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TOMOYO Linux Cross Reference
Linux/fs/aio.c

Version: ~ [ linux-6.12-rc7 ] ~ [ linux-6.11.7 ] ~ [ linux-6.10.14 ] ~ [ linux-6.9.12 ] ~ [ linux-6.8.12 ] ~ [ linux-6.7.12 ] ~ [ linux-6.6.60 ] ~ [ linux-6.5.13 ] ~ [ linux-6.4.16 ] ~ [ linux-6.3.13 ] ~ [ linux-6.2.16 ] ~ [ linux-6.1.116 ] ~ [ linux-6.0.19 ] ~ [ linux-5.19.17 ] ~ [ linux-5.18.19 ] ~ [ linux-5.17.15 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.171 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.229 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.285 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.323 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.336 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.337 ] ~ [ linux-4.4.302 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.12 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

Diff markup

Differences between /fs/aio.c (Version linux-6.12-rc7) and /fs/aio.c (Version linux-4.14.336)


  1 /*                                                  1 /*
  2  *      An async IO implementation for Linux        2  *      An async IO implementation for Linux
  3  *      Written by Benjamin LaHaise <bcrl@kvac      3  *      Written by Benjamin LaHaise <bcrl@kvack.org>
  4  *                                                  4  *
  5  *      Implements an efficient asynchronous i      5  *      Implements an efficient asynchronous io interface.
  6  *                                                  6  *
  7  *      Copyright 2000, 2001, 2002 Red Hat, In      7  *      Copyright 2000, 2001, 2002 Red Hat, Inc.  All Rights Reserved.
  8  *      Copyright 2018 Christoph Hellwig.      << 
  9  *                                                  8  *
 10  *      See ../COPYING for licensing terms.         9  *      See ../COPYING for licensing terms.
 11  */                                                10  */
 12 #define pr_fmt(fmt) "%s: " fmt, __func__           11 #define pr_fmt(fmt) "%s: " fmt, __func__
 13                                                    12 
 14 #include <linux/kernel.h>                          13 #include <linux/kernel.h>
 15 #include <linux/init.h>                            14 #include <linux/init.h>
 16 #include <linux/errno.h>                           15 #include <linux/errno.h>
 17 #include <linux/time.h>                            16 #include <linux/time.h>
 18 #include <linux/aio_abi.h>                         17 #include <linux/aio_abi.h>
 19 #include <linux/export.h>                          18 #include <linux/export.h>
 20 #include <linux/syscalls.h>                        19 #include <linux/syscalls.h>
 21 #include <linux/backing-dev.h>                     20 #include <linux/backing-dev.h>
 22 #include <linux/refcount.h>                    << 
 23 #include <linux/uio.h>                             21 #include <linux/uio.h>
 24                                                    22 
 25 #include <linux/sched/signal.h>                    23 #include <linux/sched/signal.h>
 26 #include <linux/fs.h>                              24 #include <linux/fs.h>
 27 #include <linux/file.h>                            25 #include <linux/file.h>
 28 #include <linux/mm.h>                              26 #include <linux/mm.h>
 29 #include <linux/mman.h>                            27 #include <linux/mman.h>
                                                   >>  28 #include <linux/mmu_context.h>
 30 #include <linux/percpu.h>                          29 #include <linux/percpu.h>
 31 #include <linux/slab.h>                            30 #include <linux/slab.h>
 32 #include <linux/timer.h>                           31 #include <linux/timer.h>
 33 #include <linux/aio.h>                             32 #include <linux/aio.h>
 34 #include <linux/highmem.h>                         33 #include <linux/highmem.h>
 35 #include <linux/workqueue.h>                       34 #include <linux/workqueue.h>
 36 #include <linux/security.h>                        35 #include <linux/security.h>
 37 #include <linux/eventfd.h>                         36 #include <linux/eventfd.h>
 38 #include <linux/blkdev.h>                          37 #include <linux/blkdev.h>
 39 #include <linux/compat.h>                          38 #include <linux/compat.h>
 40 #include <linux/migrate.h>                         39 #include <linux/migrate.h>
 41 #include <linux/ramfs.h>                           40 #include <linux/ramfs.h>
 42 #include <linux/percpu-refcount.h>                 41 #include <linux/percpu-refcount.h>
 43 #include <linux/mount.h>                           42 #include <linux/mount.h>
 44 #include <linux/pseudo_fs.h>                   << 
 45                                                    43 
                                                   >>  44 #include <asm/kmap_types.h>
 46 #include <linux/uaccess.h>                         45 #include <linux/uaccess.h>
 47 #include <linux/nospec.h>                          46 #include <linux/nospec.h>
 48                                                    47 
 49 #include "internal.h"                              48 #include "internal.h"
 50                                                    49 
 51 #define KIOCB_KEY               0              << 
 52                                                << 
 53 #define AIO_RING_MAGIC                  0xa10a     50 #define AIO_RING_MAGIC                  0xa10a10a1
 54 #define AIO_RING_COMPAT_FEATURES        1          51 #define AIO_RING_COMPAT_FEATURES        1
 55 #define AIO_RING_INCOMPAT_FEATURES      0          52 #define AIO_RING_INCOMPAT_FEATURES      0
 56 struct aio_ring {                                  53 struct aio_ring {
 57         unsigned        id;     /* kernel inte     54         unsigned        id;     /* kernel internal index number */
 58         unsigned        nr;     /* number of i     55         unsigned        nr;     /* number of io_events */
 59         unsigned        head;   /* Written to      56         unsigned        head;   /* Written to by userland or under ring_lock
 60                                  * mutex by ai     57                                  * mutex by aio_read_events_ring(). */
 61         unsigned        tail;                      58         unsigned        tail;
 62                                                    59 
 63         unsigned        magic;                     60         unsigned        magic;
 64         unsigned        compat_features;           61         unsigned        compat_features;
 65         unsigned        incompat_features;         62         unsigned        incompat_features;
 66         unsigned        header_length;  /* siz     63         unsigned        header_length;  /* size of aio_ring */
 67                                                    64 
 68                                                    65 
 69         struct io_event         io_events[];   !!  66         struct io_event         io_events[0];
 70 }; /* 128 bytes + ring size */                     67 }; /* 128 bytes + ring size */
 71                                                    68 
 72 /*                                             << 
 73  * Plugging is meant to work with larger batch << 
 74  * have more than the below, then don't bother << 
 75  */                                            << 
 76 #define AIO_PLUG_THRESHOLD      2              << 
 77                                                << 
 78 #define AIO_RING_PAGES  8                          69 #define AIO_RING_PAGES  8
 79                                                    70 
 80 struct kioctx_table {                              71 struct kioctx_table {
 81         struct rcu_head         rcu;               72         struct rcu_head         rcu;
 82         unsigned                nr;                73         unsigned                nr;
 83         struct kioctx __rcu     *table[] __cou !!  74         struct kioctx __rcu     *table[];
 84 };                                                 75 };
 85                                                    76 
 86 struct kioctx_cpu {                                77 struct kioctx_cpu {
 87         unsigned                reqs_available     78         unsigned                reqs_available;
 88 };                                                 79 };
 89                                                    80 
 90 struct ctx_rq_wait {                               81 struct ctx_rq_wait {
 91         struct completion comp;                    82         struct completion comp;
 92         atomic_t count;                            83         atomic_t count;
 93 };                                                 84 };
 94                                                    85 
 95 struct kioctx {                                    86 struct kioctx {
 96         struct percpu_ref       users;             87         struct percpu_ref       users;
 97         atomic_t                dead;              88         atomic_t                dead;
 98                                                    89 
 99         struct percpu_ref       reqs;              90         struct percpu_ref       reqs;
100                                                    91 
101         unsigned long           user_id;           92         unsigned long           user_id;
102                                                    93 
103         struct kioctx_cpu __percpu *cpu;       !!  94         struct __percpu kioctx_cpu *cpu;
104                                                    95 
105         /*                                         96         /*
106          * For percpu reqs_available, number o     97          * For percpu reqs_available, number of slots we move to/from global
107          * counter at a time:                      98          * counter at a time:
108          */                                        99          */
109         unsigned                req_batch;        100         unsigned                req_batch;
110         /*                                        101         /*
111          * This is what userspace passed to io    102          * This is what userspace passed to io_setup(), it's not used for
112          * anything but counting against the g    103          * anything but counting against the global max_reqs quota.
113          *                                        104          *
114          * The real limit is nr_events - 1, wh    105          * The real limit is nr_events - 1, which will be larger (see
115          * aio_setup_ring())                      106          * aio_setup_ring())
116          */                                       107          */
117         unsigned                max_reqs;         108         unsigned                max_reqs;
118                                                   109 
119         /* Size of ringbuffer, in units of str    110         /* Size of ringbuffer, in units of struct io_event */
120         unsigned                nr_events;        111         unsigned                nr_events;
121                                                   112 
122         unsigned long           mmap_base;        113         unsigned long           mmap_base;
123         unsigned long           mmap_size;        114         unsigned long           mmap_size;
124                                                   115 
125         struct folio            **ring_folios; !! 116         struct page             **ring_pages;
126         long                    nr_pages;         117         long                    nr_pages;
127                                                   118 
128         struct rcu_work         free_rwork;    !! 119         struct rcu_head         free_rcu;
                                                   >> 120         struct work_struct      free_work;      /* see free_ioctx() */
129                                                   121 
130         /*                                        122         /*
131          * signals when all in-flight requests    123          * signals when all in-flight requests are done
132          */                                       124          */
133         struct ctx_rq_wait      *rq_wait;         125         struct ctx_rq_wait      *rq_wait;
134                                                   126 
135         struct {                                  127         struct {
136                 /*                                128                 /*
137                  * This counts the number of a    129                  * This counts the number of available slots in the ringbuffer,
138                  * so we avoid overflowing it:    130                  * so we avoid overflowing it: it's decremented (if positive)
139                  * when allocating a kiocb and    131                  * when allocating a kiocb and incremented when the resulting
140                  * io_event is pulled off the     132                  * io_event is pulled off the ringbuffer.
141                  *                                133                  *
142                  * We batch accesses to it wit    134                  * We batch accesses to it with a percpu version.
143                  */                               135                  */
144                 atomic_t        reqs_available    136                 atomic_t        reqs_available;
145         } ____cacheline_aligned_in_smp;           137         } ____cacheline_aligned_in_smp;
146                                                   138 
147         struct {                                  139         struct {
148                 spinlock_t      ctx_lock;         140                 spinlock_t      ctx_lock;
149                 struct list_head active_reqs;     141                 struct list_head active_reqs;   /* used for cancellation */
150         } ____cacheline_aligned_in_smp;           142         } ____cacheline_aligned_in_smp;
151                                                   143 
152         struct {                                  144         struct {
153                 struct mutex    ring_lock;        145                 struct mutex    ring_lock;
154                 wait_queue_head_t wait;           146                 wait_queue_head_t wait;
155         } ____cacheline_aligned_in_smp;           147         } ____cacheline_aligned_in_smp;
156                                                   148 
157         struct {                                  149         struct {
158                 unsigned        tail;             150                 unsigned        tail;
159                 unsigned        completed_even    151                 unsigned        completed_events;
160                 spinlock_t      completion_loc    152                 spinlock_t      completion_lock;
161         } ____cacheline_aligned_in_smp;           153         } ____cacheline_aligned_in_smp;
162                                                   154 
163         struct folio            *internal_foli !! 155         struct page             *internal_pages[AIO_RING_PAGES];
164         struct file             *aio_ring_file    156         struct file             *aio_ring_file;
165                                                   157 
166         unsigned                id;               158         unsigned                id;
167 };                                                159 };
168                                                   160 
169 /*                                                161 /*
170  * First field must be the file pointer in all !! 162  * We use ki_cancel == KIOCB_CANCELLED to indicate that a kiocb has been either
171  * iocb unions! See also 'struct kiocb' in <li !! 163  * cancelled or completed (this makes a certain amount of sense because
                                                   >> 164  * successful cancellation - io_cancel() - does deliver the completion to
                                                   >> 165  * userspace).
                                                   >> 166  *
                                                   >> 167  * And since most things don't implement kiocb cancellation and we'd really like
                                                   >> 168  * kiocb completion to be lockless when possible, we use ki_cancel to
                                                   >> 169  * synchronize cancellation and completion - we only set it to KIOCB_CANCELLED
                                                   >> 170  * with xchg() or cmpxchg(), see batch_complete_aio() and kiocb_cancel().
172  */                                               171  */
173 struct fsync_iocb {                            !! 172 #define KIOCB_CANCELLED         ((void *) (~0ULL))
174         struct file             *file;         << 
175         struct work_struct      work;          << 
176         bool                    datasync;      << 
177         struct cred             *creds;        << 
178 };                                             << 
179                                                << 
180 struct poll_iocb {                             << 
181         struct file             *file;         << 
182         struct wait_queue_head  *head;         << 
183         __poll_t                events;        << 
184         bool                    cancelled;     << 
185         bool                    work_scheduled << 
186         bool                    work_need_resc << 
187         struct wait_queue_entry wait;          << 
188         struct work_struct      work;          << 
189 };                                             << 
190                                                   173 
191 /*                                             << 
192  * NOTE! Each of the iocb union members has th << 
193  * as the first entry in their struct definiti << 
194  * access the file pointer through any of the  << 
195  * or directly as just 'ki_filp' in this struc << 
196  */                                            << 
197 struct aio_kiocb {                                174 struct aio_kiocb {
198         union {                                !! 175         struct kiocb            common;
199                 struct file             *ki_fi << 
200                 struct kiocb            rw;    << 
201                 struct fsync_iocb       fsync; << 
202                 struct poll_iocb        poll;  << 
203         };                                     << 
204                                                   176 
205         struct kioctx           *ki_ctx;          177         struct kioctx           *ki_ctx;
206         kiocb_cancel_fn         *ki_cancel;       178         kiocb_cancel_fn         *ki_cancel;
207                                                   179 
208         struct io_event         ki_res;        !! 180         struct iocb __user      *ki_user_iocb;  /* user's aiocb */
                                                   >> 181         __u64                   ki_user_data;   /* user's data for completion */
209                                                   182 
210         struct list_head        ki_list;          183         struct list_head        ki_list;        /* the aio core uses this
211                                                   184                                                  * for cancellation */
212         refcount_t              ki_refcnt;     << 
213                                                   185 
214         /*                                        186         /*
215          * If the aio_resfd field of the users    187          * If the aio_resfd field of the userspace iocb is not zero,
216          * this is the underlying eventfd cont    188          * this is the underlying eventfd context to deliver events to.
217          */                                       189          */
218         struct eventfd_ctx      *ki_eventfd;      190         struct eventfd_ctx      *ki_eventfd;
219 };                                                191 };
220                                                   192 
221 /*------ sysctl variables----*/                   193 /*------ sysctl variables----*/
222 static DEFINE_SPINLOCK(aio_nr_lock);              194 static DEFINE_SPINLOCK(aio_nr_lock);
223 static unsigned long aio_nr;            /* cur !! 195 unsigned long aio_nr;           /* current system wide number of aio requests */
224 static unsigned long aio_max_nr = 0x10000; /*  !! 196 unsigned long aio_max_nr = 0x10000; /* system wide maximum number of aio requests */
225 /*----end sysctl variables---*/                   197 /*----end sysctl variables---*/
226 #ifdef CONFIG_SYSCTL                           << 
227 static struct ctl_table aio_sysctls[] = {      << 
228         {                                      << 
229                 .procname       = "aio-nr",    << 
230                 .data           = &aio_nr,     << 
231                 .maxlen         = sizeof(aio_n << 
232                 .mode           = 0444,        << 
233                 .proc_handler   = proc_doulong << 
234         },                                     << 
235         {                                      << 
236                 .procname       = "aio-max-nr" << 
237                 .data           = &aio_max_nr, << 
238                 .maxlen         = sizeof(aio_m << 
239                 .mode           = 0644,        << 
240                 .proc_handler   = proc_doulong << 
241         },                                     << 
242 };                                             << 
243                                                << 
244 static void __init aio_sysctl_init(void)       << 
245 {                                              << 
246         register_sysctl_init("fs", aio_sysctls << 
247 }                                              << 
248 #else                                          << 
249 #define aio_sysctl_init() do { } while (0)     << 
250 #endif                                         << 
251                                                   198 
252 static struct kmem_cache        *kiocb_cachep;    199 static struct kmem_cache        *kiocb_cachep;
253 static struct kmem_cache        *kioctx_cachep    200 static struct kmem_cache        *kioctx_cachep;
254                                                   201 
255 static struct vfsmount *aio_mnt;                  202 static struct vfsmount *aio_mnt;
256                                                   203 
257 static const struct file_operations aio_ring_f    204 static const struct file_operations aio_ring_fops;
258 static const struct address_space_operations a    205 static const struct address_space_operations aio_ctx_aops;
259                                                   206 
260 static struct file *aio_private_file(struct ki    207 static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages)
261 {                                                 208 {
                                                   >> 209         struct qstr this = QSTR_INIT("[aio]", 5);
262         struct file *file;                        210         struct file *file;
                                                   >> 211         struct path path;
263         struct inode *inode = alloc_anon_inode    212         struct inode *inode = alloc_anon_inode(aio_mnt->mnt_sb);
264         if (IS_ERR(inode))                        213         if (IS_ERR(inode))
265                 return ERR_CAST(inode);           214                 return ERR_CAST(inode);
266                                                   215 
267         inode->i_mapping->a_ops = &aio_ctx_aop    216         inode->i_mapping->a_ops = &aio_ctx_aops;
268         inode->i_mapping->i_private_data = ctx !! 217         inode->i_mapping->private_data = ctx;
269         inode->i_size = PAGE_SIZE * nr_pages;     218         inode->i_size = PAGE_SIZE * nr_pages;
270                                                   219 
271         file = alloc_file_pseudo(inode, aio_mn !! 220         path.dentry = d_alloc_pseudo(aio_mnt->mnt_sb, &this);
272                                 O_RDWR, &aio_r !! 221         if (!path.dentry) {
273         if (IS_ERR(file))                      << 
274                 iput(inode);                      222                 iput(inode);
                                                   >> 223                 return ERR_PTR(-ENOMEM);
                                                   >> 224         }
                                                   >> 225         path.mnt = mntget(aio_mnt);
                                                   >> 226 
                                                   >> 227         d_instantiate(path.dentry, inode);
                                                   >> 228         file = alloc_file(&path, FMODE_READ | FMODE_WRITE, &aio_ring_fops);
                                                   >> 229         if (IS_ERR(file)) {
                                                   >> 230                 path_put(&path);
                                                   >> 231                 return file;
                                                   >> 232         }
                                                   >> 233 
                                                   >> 234         file->f_flags = O_RDWR;
275         return file;                              235         return file;
276 }                                                 236 }
277                                                   237 
278 static int aio_init_fs_context(struct fs_conte !! 238 static struct dentry *aio_mount(struct file_system_type *fs_type,
                                                   >> 239                                 int flags, const char *dev_name, void *data)
279 {                                                 240 {
280         if (!init_pseudo(fc, AIO_RING_MAGIC))  !! 241         static const struct dentry_operations ops = {
281                 return -ENOMEM;                !! 242                 .d_dname        = simple_dname,
282         fc->s_iflags |= SB_I_NOEXEC;           !! 243         };
283         return 0;                              !! 244         struct dentry *root = mount_pseudo(fs_type, "aio:", NULL, &ops,
                                                   >> 245                                            AIO_RING_MAGIC);
                                                   >> 246 
                                                   >> 247         if (!IS_ERR(root))
                                                   >> 248                 root->d_sb->s_iflags |= SB_I_NOEXEC;
                                                   >> 249         return root;
284 }                                                 250 }
285                                                   251 
286 /* aio_setup                                      252 /* aio_setup
287  *      Creates the slab caches used by the ai    253  *      Creates the slab caches used by the aio routines, panic on
288  *      failure as this is done early during t    254  *      failure as this is done early during the boot sequence.
289  */                                               255  */
290 static int __init aio_setup(void)                 256 static int __init aio_setup(void)
291 {                                                 257 {
292         static struct file_system_type aio_fs     258         static struct file_system_type aio_fs = {
293                 .name           = "aio",          259                 .name           = "aio",
294                 .init_fs_context = aio_init_fs !! 260                 .mount          = aio_mount,
295                 .kill_sb        = kill_anon_su    261                 .kill_sb        = kill_anon_super,
296         };                                        262         };
297         aio_mnt = kern_mount(&aio_fs);            263         aio_mnt = kern_mount(&aio_fs);
298         if (IS_ERR(aio_mnt))                      264         if (IS_ERR(aio_mnt))
299                 panic("Failed to create aio fs    265                 panic("Failed to create aio fs mount.");
300                                                   266 
301         kiocb_cachep = KMEM_CACHE(aio_kiocb, S    267         kiocb_cachep = KMEM_CACHE(aio_kiocb, SLAB_HWCACHE_ALIGN|SLAB_PANIC);
302         kioctx_cachep = KMEM_CACHE(kioctx,SLAB    268         kioctx_cachep = KMEM_CACHE(kioctx,SLAB_HWCACHE_ALIGN|SLAB_PANIC);
303         aio_sysctl_init();                     !! 269 
                                                   >> 270         pr_debug("sizeof(struct page) = %zu\n", sizeof(struct page));
                                                   >> 271 
304         return 0;                                 272         return 0;
305 }                                                 273 }
306 __initcall(aio_setup);                            274 __initcall(aio_setup);
307                                                   275 
308 static void put_aio_ring_file(struct kioctx *c    276 static void put_aio_ring_file(struct kioctx *ctx)
309 {                                                 277 {
310         struct file *aio_ring_file = ctx->aio_    278         struct file *aio_ring_file = ctx->aio_ring_file;
311         struct address_space *i_mapping;          279         struct address_space *i_mapping;
312                                                   280 
313         if (aio_ring_file) {                      281         if (aio_ring_file) {
314                 truncate_setsize(file_inode(ai    282                 truncate_setsize(file_inode(aio_ring_file), 0);
315                                                   283 
316                 /* Prevent further access to t    284                 /* Prevent further access to the kioctx from migratepages */
317                 i_mapping = aio_ring_file->f_m    285                 i_mapping = aio_ring_file->f_mapping;
318                 spin_lock(&i_mapping->i_privat !! 286                 spin_lock(&i_mapping->private_lock);
319                 i_mapping->i_private_data = NU !! 287                 i_mapping->private_data = NULL;
320                 ctx->aio_ring_file = NULL;        288                 ctx->aio_ring_file = NULL;
321                 spin_unlock(&i_mapping->i_priv !! 289                 spin_unlock(&i_mapping->private_lock);
322                                                   290 
323                 fput(aio_ring_file);              291                 fput(aio_ring_file);
324         }                                         292         }
325 }                                                 293 }
326                                                   294 
327 static void aio_free_ring(struct kioctx *ctx)     295 static void aio_free_ring(struct kioctx *ctx)
328 {                                                 296 {
329         int i;                                    297         int i;
330                                                   298 
331         /* Disconnect the kiotx from the ring     299         /* Disconnect the kiotx from the ring file.  This prevents future
332          * accesses to the kioctx from page mi    300          * accesses to the kioctx from page migration.
333          */                                       301          */
334         put_aio_ring_file(ctx);                   302         put_aio_ring_file(ctx);
335                                                   303 
336         for (i = 0; i < ctx->nr_pages; i++) {     304         for (i = 0; i < ctx->nr_pages; i++) {
337                 struct folio *folio = ctx->rin !! 305                 struct page *page;
338                                                !! 306                 pr_debug("pid(%d) [%d] page->count=%d\n", current->pid, i,
339                 if (!folio)                    !! 307                                 page_count(ctx->ring_pages[i]));
                                                   >> 308                 page = ctx->ring_pages[i];
                                                   >> 309                 if (!page)
340                         continue;                 310                         continue;
341                                                !! 311                 ctx->ring_pages[i] = NULL;
342                 pr_debug("pid(%d) [%d] folio-> !! 312                 put_page(page);
343                          folio_ref_count(folio << 
344                 ctx->ring_folios[i] = NULL;    << 
345                 folio_put(folio);              << 
346         }                                         313         }
347                                                   314 
348         if (ctx->ring_folios && ctx->ring_foli !! 315         if (ctx->ring_pages && ctx->ring_pages != ctx->internal_pages) {
349                 kfree(ctx->ring_folios);       !! 316                 kfree(ctx->ring_pages);
350                 ctx->ring_folios = NULL;       !! 317                 ctx->ring_pages = NULL;
351         }                                         318         }
352 }                                                 319 }
353                                                   320 
354 static int aio_ring_mremap(struct vm_area_stru    321 static int aio_ring_mremap(struct vm_area_struct *vma)
355 {                                                 322 {
356         struct file *file = vma->vm_file;         323         struct file *file = vma->vm_file;
357         struct mm_struct *mm = vma->vm_mm;        324         struct mm_struct *mm = vma->vm_mm;
358         struct kioctx_table *table;               325         struct kioctx_table *table;
359         int i, res = -EINVAL;                     326         int i, res = -EINVAL;
360                                                   327 
361         spin_lock(&mm->ioctx_lock);               328         spin_lock(&mm->ioctx_lock);
362         rcu_read_lock();                          329         rcu_read_lock();
363         table = rcu_dereference(mm->ioctx_tabl    330         table = rcu_dereference(mm->ioctx_table);
364         if (!table)                               331         if (!table)
365                 goto out_unlock;                  332                 goto out_unlock;
366                                                   333 
367         for (i = 0; i < table->nr; i++) {         334         for (i = 0; i < table->nr; i++) {
368                 struct kioctx *ctx;               335                 struct kioctx *ctx;
369                                                   336 
370                 ctx = rcu_dereference(table->t    337                 ctx = rcu_dereference(table->table[i]);
371                 if (ctx && ctx->aio_ring_file     338                 if (ctx && ctx->aio_ring_file == file) {
372                         if (!atomic_read(&ctx-    339                         if (!atomic_read(&ctx->dead)) {
373                                 ctx->user_id =    340                                 ctx->user_id = ctx->mmap_base = vma->vm_start;
374                                 res = 0;          341                                 res = 0;
375                         }                         342                         }
376                         break;                    343                         break;
377                 }                                 344                 }
378         }                                         345         }
379                                                   346 
380 out_unlock:                                       347 out_unlock:
381         rcu_read_unlock();                        348         rcu_read_unlock();
382         spin_unlock(&mm->ioctx_lock);             349         spin_unlock(&mm->ioctx_lock);
383         return res;                               350         return res;
384 }                                                 351 }
385                                                   352 
386 static const struct vm_operations_struct aio_r    353 static const struct vm_operations_struct aio_ring_vm_ops = {
387         .mremap         = aio_ring_mremap,        354         .mremap         = aio_ring_mremap,
388 #if IS_ENABLED(CONFIG_MMU)                        355 #if IS_ENABLED(CONFIG_MMU)
389         .fault          = filemap_fault,          356         .fault          = filemap_fault,
390         .map_pages      = filemap_map_pages,      357         .map_pages      = filemap_map_pages,
391         .page_mkwrite   = filemap_page_mkwrite    358         .page_mkwrite   = filemap_page_mkwrite,
392 #endif                                            359 #endif
393 };                                                360 };
394                                                   361 
395 static int aio_ring_mmap(struct file *file, st    362 static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma)
396 {                                                 363 {
397         vm_flags_set(vma, VM_DONTEXPAND);      !! 364         vma->vm_flags |= VM_DONTEXPAND;
398         vma->vm_ops = &aio_ring_vm_ops;           365         vma->vm_ops = &aio_ring_vm_ops;
399         return 0;                                 366         return 0;
400 }                                                 367 }
401                                                   368 
402 static const struct file_operations aio_ring_f    369 static const struct file_operations aio_ring_fops = {
403         .mmap = aio_ring_mmap,                    370         .mmap = aio_ring_mmap,
404 };                                                371 };
405                                                   372 
406 #if IS_ENABLED(CONFIG_MIGRATION)                  373 #if IS_ENABLED(CONFIG_MIGRATION)
407 static int aio_migrate_folio(struct address_sp !! 374 static int aio_migratepage(struct address_space *mapping, struct page *new,
408                         struct folio *src, enu !! 375                         struct page *old, enum migrate_mode mode)
409 {                                                 376 {
410         struct kioctx *ctx;                       377         struct kioctx *ctx;
411         unsigned long flags;                      378         unsigned long flags;
412         pgoff_t idx;                              379         pgoff_t idx;
413         int rc = 0;                            !! 380         int rc;
                                                   >> 381 
                                                   >> 382         /*
                                                   >> 383          * We cannot support the _NO_COPY case here, because copy needs to
                                                   >> 384          * happen under the ctx->completion_lock. That does not work with the
                                                   >> 385          * migration workflow of MIGRATE_SYNC_NO_COPY.
                                                   >> 386          */
                                                   >> 387         if (mode == MIGRATE_SYNC_NO_COPY)
                                                   >> 388                 return -EINVAL;
414                                                   389 
415         /* mapping->i_private_lock here protec !! 390         rc = 0;
416         spin_lock(&mapping->i_private_lock);   !! 391 
417         ctx = mapping->i_private_data;         !! 392         /* mapping->private_lock here protects against the kioctx teardown.  */
                                                   >> 393         spin_lock(&mapping->private_lock);
                                                   >> 394         ctx = mapping->private_data;
418         if (!ctx) {                               395         if (!ctx) {
419                 rc = -EINVAL;                     396                 rc = -EINVAL;
420                 goto out;                         397                 goto out;
421         }                                         398         }
422                                                   399 
423         /* The ring_lock mutex.  The prevents     400         /* The ring_lock mutex.  The prevents aio_read_events() from writing
424          * to the ring's head, and prevents pa    401          * to the ring's head, and prevents page migration from mucking in
425          * a partially initialized kiotx.         402          * a partially initialized kiotx.
426          */                                       403          */
427         if (!mutex_trylock(&ctx->ring_lock)) {    404         if (!mutex_trylock(&ctx->ring_lock)) {
428                 rc = -EAGAIN;                     405                 rc = -EAGAIN;
429                 goto out;                         406                 goto out;
430         }                                         407         }
431                                                   408 
432         idx = src->index;                      !! 409         idx = old->index;
433         if (idx < (pgoff_t)ctx->nr_pages) {       410         if (idx < (pgoff_t)ctx->nr_pages) {
434                 /* Make sure the old folio has !! 411                 /* Make sure the old page hasn't already been changed */
435                 if (ctx->ring_folios[idx] != s !! 412                 if (ctx->ring_pages[idx] != old)
436                         rc = -EAGAIN;             413                         rc = -EAGAIN;
437         } else                                    414         } else
438                 rc = -EINVAL;                     415                 rc = -EINVAL;
439                                                   416 
440         if (rc != 0)                              417         if (rc != 0)
441                 goto out_unlock;                  418                 goto out_unlock;
442                                                   419 
443         /* Writeback must be complete */          420         /* Writeback must be complete */
444         BUG_ON(folio_test_writeback(src));     !! 421         BUG_ON(PageWriteback(old));
445         folio_get(dst);                        !! 422         get_page(new);
446                                                   423 
447         rc = folio_migrate_mapping(mapping, ds !! 424         rc = migrate_page_move_mapping(mapping, new, old, NULL, mode, 1);
448         if (rc != MIGRATEPAGE_SUCCESS) {          425         if (rc != MIGRATEPAGE_SUCCESS) {
449                 folio_put(dst);                !! 426                 put_page(new);
450                 goto out_unlock;                  427                 goto out_unlock;
451         }                                         428         }
452                                                   429 
453         /* Take completion_lock to prevent oth    430         /* Take completion_lock to prevent other writes to the ring buffer
454          * while the old folio is copied to th !! 431          * while the old page is copied to the new.  This prevents new
455          * events from being lost.                432          * events from being lost.
456          */                                       433          */
457         spin_lock_irqsave(&ctx->completion_loc    434         spin_lock_irqsave(&ctx->completion_lock, flags);
458         folio_copy(dst, src);                  !! 435         migrate_page_copy(new, old);
459         folio_migrate_flags(dst, src);         !! 436         BUG_ON(ctx->ring_pages[idx] != old);
460         BUG_ON(ctx->ring_folios[idx] != src);  !! 437         ctx->ring_pages[idx] = new;
461         ctx->ring_folios[idx] = dst;           << 
462         spin_unlock_irqrestore(&ctx->completio    438         spin_unlock_irqrestore(&ctx->completion_lock, flags);
463                                                   439 
464         /* The old folio is no longer accessib !! 440         /* The old page is no longer accessible. */
465         folio_put(src);                        !! 441         put_page(old);
466                                                   442 
467 out_unlock:                                       443 out_unlock:
468         mutex_unlock(&ctx->ring_lock);            444         mutex_unlock(&ctx->ring_lock);
469 out:                                              445 out:
470         spin_unlock(&mapping->i_private_lock); !! 446         spin_unlock(&mapping->private_lock);
471         return rc;                                447         return rc;
472 }                                                 448 }
473 #else                                          << 
474 #define aio_migrate_folio NULL                 << 
475 #endif                                            449 #endif
476                                                   450 
477 static const struct address_space_operations a    451 static const struct address_space_operations aio_ctx_aops = {
478         .dirty_folio    = noop_dirty_folio,    !! 452         .set_page_dirty = __set_page_dirty_no_writeback,
479         .migrate_folio  = aio_migrate_folio,   !! 453 #if IS_ENABLED(CONFIG_MIGRATION)
                                                   >> 454         .migratepage    = aio_migratepage,
                                                   >> 455 #endif
480 };                                                456 };
481                                                   457 
482 static int aio_setup_ring(struct kioctx *ctx,     458 static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
483 {                                                 459 {
484         struct aio_ring *ring;                    460         struct aio_ring *ring;
485         struct mm_struct *mm = current->mm;       461         struct mm_struct *mm = current->mm;
486         unsigned long size, unused;               462         unsigned long size, unused;
487         int nr_pages;                             463         int nr_pages;
488         int i;                                    464         int i;
489         struct file *file;                        465         struct file *file;
490                                                   466 
491         /* Compensate for the ring buffer's he    467         /* Compensate for the ring buffer's head/tail overlap entry */
492         nr_events += 2; /* 1 is required, 2 fo    468         nr_events += 2; /* 1 is required, 2 for good luck */
493                                                   469 
494         size = sizeof(struct aio_ring);           470         size = sizeof(struct aio_ring);
495         size += sizeof(struct io_event) * nr_e    471         size += sizeof(struct io_event) * nr_events;
496                                                   472 
497         nr_pages = PFN_UP(size);                  473         nr_pages = PFN_UP(size);
498         if (nr_pages < 0)                         474         if (nr_pages < 0)
499                 return -EINVAL;                   475                 return -EINVAL;
500                                                   476 
501         file = aio_private_file(ctx, nr_pages)    477         file = aio_private_file(ctx, nr_pages);
502         if (IS_ERR(file)) {                       478         if (IS_ERR(file)) {
503                 ctx->aio_ring_file = NULL;        479                 ctx->aio_ring_file = NULL;
504                 return -ENOMEM;                   480                 return -ENOMEM;
505         }                                         481         }
506                                                   482 
507         ctx->aio_ring_file = file;                483         ctx->aio_ring_file = file;
508         nr_events = (PAGE_SIZE * nr_pages - si    484         nr_events = (PAGE_SIZE * nr_pages - sizeof(struct aio_ring))
509                         / sizeof(struct io_eve    485                         / sizeof(struct io_event);
510                                                   486 
511         ctx->ring_folios = ctx->internal_folio !! 487         ctx->ring_pages = ctx->internal_pages;
512         if (nr_pages > AIO_RING_PAGES) {          488         if (nr_pages > AIO_RING_PAGES) {
513                 ctx->ring_folios = kcalloc(nr_ !! 489                 ctx->ring_pages = kcalloc(nr_pages, sizeof(struct page *),
514                                            GFP !! 490                                           GFP_KERNEL);
515                 if (!ctx->ring_folios) {       !! 491                 if (!ctx->ring_pages) {
516                         put_aio_ring_file(ctx)    492                         put_aio_ring_file(ctx);
517                         return -ENOMEM;           493                         return -ENOMEM;
518                 }                                 494                 }
519         }                                         495         }
520                                                   496 
521         for (i = 0; i < nr_pages; i++) {          497         for (i = 0; i < nr_pages; i++) {
522                 struct folio *folio;           !! 498                 struct page *page;
523                                                !! 499                 page = find_or_create_page(file->f_mapping,
524                 folio = __filemap_get_folio(fi !! 500                                            i, GFP_HIGHUSER | __GFP_ZERO);
525                                             FG !! 501                 if (!page)
526                                             GF << 
527                 if (IS_ERR(folio))             << 
528                         break;                    502                         break;
                                                   >> 503                 pr_debug("pid(%d) page[%d]->count=%d\n",
                                                   >> 504                          current->pid, i, page_count(page));
                                                   >> 505                 SetPageUptodate(page);
                                                   >> 506                 unlock_page(page);
529                                                   507 
530                 pr_debug("pid(%d) [%d] folio-> !! 508                 ctx->ring_pages[i] = page;
531                          folio_ref_count(folio << 
532                 folio_end_read(folio, true);   << 
533                                                << 
534                 ctx->ring_folios[i] = folio;   << 
535         }                                         509         }
536         ctx->nr_pages = i;                        510         ctx->nr_pages = i;
537                                                   511 
538         if (unlikely(i != nr_pages)) {            512         if (unlikely(i != nr_pages)) {
539                 aio_free_ring(ctx);               513                 aio_free_ring(ctx);
540                 return -ENOMEM;                   514                 return -ENOMEM;
541         }                                         515         }
542                                                   516 
543         ctx->mmap_size = nr_pages * PAGE_SIZE;    517         ctx->mmap_size = nr_pages * PAGE_SIZE;
544         pr_debug("attempting mmap of %lu bytes    518         pr_debug("attempting mmap of %lu bytes\n", ctx->mmap_size);
545                                                   519 
546         if (mmap_write_lock_killable(mm)) {    !! 520         if (down_write_killable(&mm->mmap_sem)) {
547                 ctx->mmap_size = 0;               521                 ctx->mmap_size = 0;
548                 aio_free_ring(ctx);               522                 aio_free_ring(ctx);
549                 return -EINTR;                    523                 return -EINTR;
550         }                                         524         }
551                                                   525 
552         ctx->mmap_base = do_mmap(ctx->aio_ring !! 526         ctx->mmap_base = do_mmap_pgoff(ctx->aio_ring_file, 0, ctx->mmap_size,
553                                  PROT_READ | P !! 527                                        PROT_READ | PROT_WRITE,
554                                  MAP_SHARED, 0 !! 528                                        MAP_SHARED, 0, &unused, NULL);
555         mmap_write_unlock(mm);                 !! 529         up_write(&mm->mmap_sem);
556         if (IS_ERR((void *)ctx->mmap_base)) {     530         if (IS_ERR((void *)ctx->mmap_base)) {
557                 ctx->mmap_size = 0;               531                 ctx->mmap_size = 0;
558                 aio_free_ring(ctx);               532                 aio_free_ring(ctx);
559                 return -ENOMEM;                   533                 return -ENOMEM;
560         }                                         534         }
561                                                   535 
562         pr_debug("mmap address: 0x%08lx\n", ct    536         pr_debug("mmap address: 0x%08lx\n", ctx->mmap_base);
563                                                   537 
564         ctx->user_id = ctx->mmap_base;            538         ctx->user_id = ctx->mmap_base;
565         ctx->nr_events = nr_events; /* trusted    539         ctx->nr_events = nr_events; /* trusted copy */
566                                                   540 
567         ring = folio_address(ctx->ring_folios[ !! 541         ring = kmap_atomic(ctx->ring_pages[0]);
568         ring->nr = nr_events;   /* user copy *    542         ring->nr = nr_events;   /* user copy */
569         ring->id = ~0U;                           543         ring->id = ~0U;
570         ring->head = ring->tail = 0;              544         ring->head = ring->tail = 0;
571         ring->magic = AIO_RING_MAGIC;             545         ring->magic = AIO_RING_MAGIC;
572         ring->compat_features = AIO_RING_COMPA    546         ring->compat_features = AIO_RING_COMPAT_FEATURES;
573         ring->incompat_features = AIO_RING_INC    547         ring->incompat_features = AIO_RING_INCOMPAT_FEATURES;
574         ring->header_length = sizeof(struct ai    548         ring->header_length = sizeof(struct aio_ring);
575         flush_dcache_folio(ctx->ring_folios[0] !! 549         kunmap_atomic(ring);
                                                   >> 550         flush_dcache_page(ctx->ring_pages[0]);
576                                                   551 
577         return 0;                                 552         return 0;
578 }                                                 553 }
579                                                   554 
580 #define AIO_EVENTS_PER_PAGE     (PAGE_SIZE / s    555 #define AIO_EVENTS_PER_PAGE     (PAGE_SIZE / sizeof(struct io_event))
581 #define AIO_EVENTS_FIRST_PAGE   ((PAGE_SIZE -     556 #define AIO_EVENTS_FIRST_PAGE   ((PAGE_SIZE - sizeof(struct aio_ring)) / sizeof(struct io_event))
582 #define AIO_EVENTS_OFFSET       (AIO_EVENTS_PE    557 #define AIO_EVENTS_OFFSET       (AIO_EVENTS_PER_PAGE - AIO_EVENTS_FIRST_PAGE)
583                                                   558 
584 void kiocb_set_cancel_fn(struct kiocb *iocb, k    559 void kiocb_set_cancel_fn(struct kiocb *iocb, kiocb_cancel_fn *cancel)
585 {                                                 560 {
586         struct aio_kiocb *req;                 !! 561         struct aio_kiocb *req = container_of(iocb, struct aio_kiocb, common);
587         struct kioctx *ctx;                    !! 562         struct kioctx *ctx = req->ki_ctx;
588         unsigned long flags;                      563         unsigned long flags;
589                                                   564 
590         /*                                     !! 565         spin_lock_irqsave(&ctx->ctx_lock, flags);
591          * kiocb didn't come from aio or is ne << 
592          * ignore it.                          << 
593          */                                    << 
594         if (!(iocb->ki_flags & IOCB_AIO_RW))   << 
595                 return;                        << 
596                                                << 
597         req = container_of(iocb, struct aio_ki << 
598                                                << 
599         if (WARN_ON_ONCE(!list_empty(&req->ki_ << 
600                 return;                        << 
601                                                   566 
602         ctx = req->ki_ctx;                     !! 567         if (!req->ki_list.next)
                                                   >> 568                 list_add(&req->ki_list, &ctx->active_reqs);
603                                                   569 
604         spin_lock_irqsave(&ctx->ctx_lock, flag << 
605         list_add_tail(&req->ki_list, &ctx->act << 
606         req->ki_cancel = cancel;                  570         req->ki_cancel = cancel;
                                                   >> 571 
607         spin_unlock_irqrestore(&ctx->ctx_lock,    572         spin_unlock_irqrestore(&ctx->ctx_lock, flags);
608 }                                                 573 }
609 EXPORT_SYMBOL(kiocb_set_cancel_fn);               574 EXPORT_SYMBOL(kiocb_set_cancel_fn);
610                                                   575 
                                                   >> 576 static int kiocb_cancel(struct aio_kiocb *kiocb)
                                                   >> 577 {
                                                   >> 578         kiocb_cancel_fn *old, *cancel;
                                                   >> 579 
                                                   >> 580         /*
                                                   >> 581          * Don't want to set kiocb->ki_cancel = KIOCB_CANCELLED unless it
                                                   >> 582          * actually has a cancel function, hence the cmpxchg()
                                                   >> 583          */
                                                   >> 584 
                                                   >> 585         cancel = ACCESS_ONCE(kiocb->ki_cancel);
                                                   >> 586         do {
                                                   >> 587                 if (!cancel || cancel == KIOCB_CANCELLED)
                                                   >> 588                         return -EINVAL;
                                                   >> 589 
                                                   >> 590                 old = cancel;
                                                   >> 591                 cancel = cmpxchg(&kiocb->ki_cancel, old, KIOCB_CANCELLED);
                                                   >> 592         } while (cancel != old);
                                                   >> 593 
                                                   >> 594         return cancel(&kiocb->common);
                                                   >> 595 }
                                                   >> 596 
611 /*                                                597 /*
612  * free_ioctx() should be RCU delayed to synch    598  * free_ioctx() should be RCU delayed to synchronize against the RCU
613  * protected lookup_ioctx() and also needs pro    599  * protected lookup_ioctx() and also needs process context to call
614  * aio_free_ring().  Use rcu_work.             !! 600  * aio_free_ring(), so the double bouncing through kioctx->free_rcu and
                                                   >> 601  * ->free_work.
615  */                                               602  */
616 static void free_ioctx(struct work_struct *wor    603 static void free_ioctx(struct work_struct *work)
617 {                                                 604 {
618         struct kioctx *ctx = container_of(to_r !! 605         struct kioctx *ctx = container_of(work, struct kioctx, free_work);
619                                           free !! 606 
620         pr_debug("freeing %p\n", ctx);            607         pr_debug("freeing %p\n", ctx);
621                                                   608 
622         aio_free_ring(ctx);                       609         aio_free_ring(ctx);
623         free_percpu(ctx->cpu);                    610         free_percpu(ctx->cpu);
624         percpu_ref_exit(&ctx->reqs);              611         percpu_ref_exit(&ctx->reqs);
625         percpu_ref_exit(&ctx->users);             612         percpu_ref_exit(&ctx->users);
626         kmem_cache_free(kioctx_cachep, ctx);      613         kmem_cache_free(kioctx_cachep, ctx);
627 }                                                 614 }
628                                                   615 
                                                   >> 616 static void free_ioctx_rcufn(struct rcu_head *head)
                                                   >> 617 {
                                                   >> 618         struct kioctx *ctx = container_of(head, struct kioctx, free_rcu);
                                                   >> 619 
                                                   >> 620         INIT_WORK(&ctx->free_work, free_ioctx);
                                                   >> 621         schedule_work(&ctx->free_work);
                                                   >> 622 }
                                                   >> 623 
629 static void free_ioctx_reqs(struct percpu_ref     624 static void free_ioctx_reqs(struct percpu_ref *ref)
630 {                                                 625 {
631         struct kioctx *ctx = container_of(ref,    626         struct kioctx *ctx = container_of(ref, struct kioctx, reqs);
632                                                   627 
633         /* At this point we know that there ar    628         /* At this point we know that there are no any in-flight requests */
634         if (ctx->rq_wait && atomic_dec_and_tes    629         if (ctx->rq_wait && atomic_dec_and_test(&ctx->rq_wait->count))
635                 complete(&ctx->rq_wait->comp);    630                 complete(&ctx->rq_wait->comp);
636                                                   631 
637         /* Synchronize against RCU protected t    632         /* Synchronize against RCU protected table->table[] dereferences */
638         INIT_RCU_WORK(&ctx->free_rwork, free_i !! 633         call_rcu(&ctx->free_rcu, free_ioctx_rcufn);
639         queue_rcu_work(system_wq, &ctx->free_r << 
640 }                                                 634 }
641                                                   635 
642 /*                                                636 /*
643  * When this function runs, the kioctx has bee    637  * When this function runs, the kioctx has been removed from the "hash table"
644  * and ctx->users has dropped to 0, so we know    638  * and ctx->users has dropped to 0, so we know no more kiocbs can be submitted -
645  * now it's safe to cancel any that need to be    639  * now it's safe to cancel any that need to be.
646  */                                               640  */
647 static void free_ioctx_users(struct percpu_ref    641 static void free_ioctx_users(struct percpu_ref *ref)
648 {                                                 642 {
649         struct kioctx *ctx = container_of(ref,    643         struct kioctx *ctx = container_of(ref, struct kioctx, users);
650         struct aio_kiocb *req;                    644         struct aio_kiocb *req;
651                                                   645 
652         spin_lock_irq(&ctx->ctx_lock);            646         spin_lock_irq(&ctx->ctx_lock);
653                                                   647 
654         while (!list_empty(&ctx->active_reqs))    648         while (!list_empty(&ctx->active_reqs)) {
655                 req = list_first_entry(&ctx->a    649                 req = list_first_entry(&ctx->active_reqs,
656                                        struct     650                                        struct aio_kiocb, ki_list);
657                 req->ki_cancel(&req->rw);      !! 651                 kiocb_cancel(req);
658                 list_del_init(&req->ki_list);     652                 list_del_init(&req->ki_list);
659         }                                         653         }
660                                                   654 
661         spin_unlock_irq(&ctx->ctx_lock);          655         spin_unlock_irq(&ctx->ctx_lock);
662                                                   656 
663         percpu_ref_kill(&ctx->reqs);              657         percpu_ref_kill(&ctx->reqs);
664         percpu_ref_put(&ctx->reqs);               658         percpu_ref_put(&ctx->reqs);
665 }                                                 659 }
666                                                   660 
667 static int ioctx_add_table(struct kioctx *ctx,    661 static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
668 {                                                 662 {
669         unsigned i, new_nr;                       663         unsigned i, new_nr;
670         struct kioctx_table *table, *old;         664         struct kioctx_table *table, *old;
671         struct aio_ring *ring;                    665         struct aio_ring *ring;
672                                                   666 
673         spin_lock(&mm->ioctx_lock);               667         spin_lock(&mm->ioctx_lock);
674         table = rcu_dereference_raw(mm->ioctx_    668         table = rcu_dereference_raw(mm->ioctx_table);
675                                                   669 
676         while (1) {                               670         while (1) {
677                 if (table)                        671                 if (table)
678                         for (i = 0; i < table-    672                         for (i = 0; i < table->nr; i++)
679                                 if (!rcu_acces    673                                 if (!rcu_access_pointer(table->table[i])) {
680                                         ctx->i    674                                         ctx->id = i;
681                                         rcu_as    675                                         rcu_assign_pointer(table->table[i], ctx);
682                                         spin_u    676                                         spin_unlock(&mm->ioctx_lock);
683                                                   677 
684                                         /* Whi    678                                         /* While kioctx setup is in progress,
685                                          * we     679                                          * we are protected from page migration
686                                          * cha !! 680                                          * changes ring_pages by ->ring_lock.
687                                          */       681                                          */
688                                         ring = !! 682                                         ring = kmap_atomic(ctx->ring_pages[0]);
689                                         ring->    683                                         ring->id = ctx->id;
                                                   >> 684                                         kunmap_atomic(ring);
690                                         return    685                                         return 0;
691                                 }                 686                                 }
692                                                   687 
693                 new_nr = (table ? table->nr :     688                 new_nr = (table ? table->nr : 1) * 4;
694                 spin_unlock(&mm->ioctx_lock);     689                 spin_unlock(&mm->ioctx_lock);
695                                                   690 
696                 table = kzalloc(struct_size(ta !! 691                 table = kzalloc(sizeof(*table) + sizeof(struct kioctx *) *
                                                   >> 692                                 new_nr, GFP_KERNEL);
697                 if (!table)                       693                 if (!table)
698                         return -ENOMEM;           694                         return -ENOMEM;
699                                                   695 
700                 table->nr = new_nr;               696                 table->nr = new_nr;
701                                                   697 
702                 spin_lock(&mm->ioctx_lock);       698                 spin_lock(&mm->ioctx_lock);
703                 old = rcu_dereference_raw(mm->    699                 old = rcu_dereference_raw(mm->ioctx_table);
704                                                   700 
705                 if (!old) {                       701                 if (!old) {
706                         rcu_assign_pointer(mm-    702                         rcu_assign_pointer(mm->ioctx_table, table);
707                 } else if (table->nr > old->nr    703                 } else if (table->nr > old->nr) {
708                         memcpy(table->table, o    704                         memcpy(table->table, old->table,
709                                old->nr * sizeo    705                                old->nr * sizeof(struct kioctx *));
710                                                   706 
711                         rcu_assign_pointer(mm-    707                         rcu_assign_pointer(mm->ioctx_table, table);
712                         kfree_rcu(old, rcu);      708                         kfree_rcu(old, rcu);
713                 } else {                          709                 } else {
714                         kfree(table);             710                         kfree(table);
715                         table = old;              711                         table = old;
716                 }                                 712                 }
717         }                                         713         }
718 }                                                 714 }
719                                                   715 
720 static void aio_nr_sub(unsigned nr)               716 static void aio_nr_sub(unsigned nr)
721 {                                                 717 {
722         spin_lock(&aio_nr_lock);                  718         spin_lock(&aio_nr_lock);
723         if (WARN_ON(aio_nr - nr > aio_nr))        719         if (WARN_ON(aio_nr - nr > aio_nr))
724                 aio_nr = 0;                       720                 aio_nr = 0;
725         else                                      721         else
726                 aio_nr -= nr;                     722                 aio_nr -= nr;
727         spin_unlock(&aio_nr_lock);                723         spin_unlock(&aio_nr_lock);
728 }                                                 724 }
729                                                   725 
730 /* ioctx_alloc                                    726 /* ioctx_alloc
731  *      Allocates and initializes an ioctx.  R    727  *      Allocates and initializes an ioctx.  Returns an ERR_PTR if it failed.
732  */                                               728  */
733 static struct kioctx *ioctx_alloc(unsigned nr_    729 static struct kioctx *ioctx_alloc(unsigned nr_events)
734 {                                                 730 {
735         struct mm_struct *mm = current->mm;       731         struct mm_struct *mm = current->mm;
736         struct kioctx *ctx;                       732         struct kioctx *ctx;
737         int err = -ENOMEM;                        733         int err = -ENOMEM;
738                                                   734 
739         /*                                        735         /*
740          * Store the original nr_events -- wha    736          * Store the original nr_events -- what userspace passed to io_setup(),
741          * for counting against the global lim    737          * for counting against the global limit -- before it changes.
742          */                                       738          */
743         unsigned int max_reqs = nr_events;        739         unsigned int max_reqs = nr_events;
744                                                   740 
745         /*                                        741         /*
746          * We keep track of the number of avai    742          * We keep track of the number of available ringbuffer slots, to prevent
747          * overflow (reqs_available), and we a    743          * overflow (reqs_available), and we also use percpu counters for this.
748          *                                        744          *
749          * So since up to half the slots might    745          * So since up to half the slots might be on other cpu's percpu counters
750          * and unavailable, double nr_events s    746          * and unavailable, double nr_events so userspace sees what they
751          * expected: additionally, we move req    747          * expected: additionally, we move req_batch slots to/from percpu
752          * counters at a time, so make sure th    748          * counters at a time, so make sure that isn't 0:
753          */                                       749          */
754         nr_events = max(nr_events, num_possibl    750         nr_events = max(nr_events, num_possible_cpus() * 4);
755         nr_events *= 2;                           751         nr_events *= 2;
756                                                   752 
757         /* Prevent overflows */                   753         /* Prevent overflows */
758         if (nr_events > (0x10000000U / sizeof(    754         if (nr_events > (0x10000000U / sizeof(struct io_event))) {
759                 pr_debug("ENOMEM: nr_events to    755                 pr_debug("ENOMEM: nr_events too high\n");
760                 return ERR_PTR(-EINVAL);          756                 return ERR_PTR(-EINVAL);
761         }                                         757         }
762                                                   758 
763         if (!nr_events || (unsigned long)max_r    759         if (!nr_events || (unsigned long)max_reqs > aio_max_nr)
764                 return ERR_PTR(-EAGAIN);          760                 return ERR_PTR(-EAGAIN);
765                                                   761 
766         ctx = kmem_cache_zalloc(kioctx_cachep,    762         ctx = kmem_cache_zalloc(kioctx_cachep, GFP_KERNEL);
767         if (!ctx)                                 763         if (!ctx)
768                 return ERR_PTR(-ENOMEM);          764                 return ERR_PTR(-ENOMEM);
769                                                   765 
770         ctx->max_reqs = max_reqs;                 766         ctx->max_reqs = max_reqs;
771                                                   767 
772         spin_lock_init(&ctx->ctx_lock);           768         spin_lock_init(&ctx->ctx_lock);
773         spin_lock_init(&ctx->completion_lock);    769         spin_lock_init(&ctx->completion_lock);
774         mutex_init(&ctx->ring_lock);              770         mutex_init(&ctx->ring_lock);
775         /* Protect against page migration thro    771         /* Protect against page migration throughout kiotx setup by keeping
776          * the ring_lock mutex held until setu    772          * the ring_lock mutex held until setup is complete. */
777         mutex_lock(&ctx->ring_lock);              773         mutex_lock(&ctx->ring_lock);
778         init_waitqueue_head(&ctx->wait);          774         init_waitqueue_head(&ctx->wait);
779                                                   775 
780         INIT_LIST_HEAD(&ctx->active_reqs);        776         INIT_LIST_HEAD(&ctx->active_reqs);
781                                                   777 
782         if (percpu_ref_init(&ctx->users, free_    778         if (percpu_ref_init(&ctx->users, free_ioctx_users, 0, GFP_KERNEL))
783                 goto err;                         779                 goto err;
784                                                   780 
785         if (percpu_ref_init(&ctx->reqs, free_i    781         if (percpu_ref_init(&ctx->reqs, free_ioctx_reqs, 0, GFP_KERNEL))
786                 goto err;                         782                 goto err;
787                                                   783 
788         ctx->cpu = alloc_percpu(struct kioctx_    784         ctx->cpu = alloc_percpu(struct kioctx_cpu);
789         if (!ctx->cpu)                            785         if (!ctx->cpu)
790                 goto err;                         786                 goto err;
791                                                   787 
792         err = aio_setup_ring(ctx, nr_events);     788         err = aio_setup_ring(ctx, nr_events);
793         if (err < 0)                              789         if (err < 0)
794                 goto err;                         790                 goto err;
795                                                   791 
796         atomic_set(&ctx->reqs_available, ctx->    792         atomic_set(&ctx->reqs_available, ctx->nr_events - 1);
797         ctx->req_batch = (ctx->nr_events - 1)     793         ctx->req_batch = (ctx->nr_events - 1) / (num_possible_cpus() * 4);
798         if (ctx->req_batch < 1)                   794         if (ctx->req_batch < 1)
799                 ctx->req_batch = 1;               795                 ctx->req_batch = 1;
800                                                   796 
801         /* limit the number of system wide aio    797         /* limit the number of system wide aios */
802         spin_lock(&aio_nr_lock);                  798         spin_lock(&aio_nr_lock);
803         if (aio_nr + ctx->max_reqs > aio_max_n    799         if (aio_nr + ctx->max_reqs > aio_max_nr ||
804             aio_nr + ctx->max_reqs < aio_nr) {    800             aio_nr + ctx->max_reqs < aio_nr) {
805                 spin_unlock(&aio_nr_lock);        801                 spin_unlock(&aio_nr_lock);
806                 err = -EAGAIN;                    802                 err = -EAGAIN;
807                 goto err_ctx;                     803                 goto err_ctx;
808         }                                         804         }
809         aio_nr += ctx->max_reqs;                  805         aio_nr += ctx->max_reqs;
810         spin_unlock(&aio_nr_lock);                806         spin_unlock(&aio_nr_lock);
811                                                   807 
812         percpu_ref_get(&ctx->users);    /* io_    808         percpu_ref_get(&ctx->users);    /* io_setup() will drop this ref */
813         percpu_ref_get(&ctx->reqs);     /* fre    809         percpu_ref_get(&ctx->reqs);     /* free_ioctx_users() will drop this */
814                                                   810 
815         err = ioctx_add_table(ctx, mm);           811         err = ioctx_add_table(ctx, mm);
816         if (err)                                  812         if (err)
817                 goto err_cleanup;                 813                 goto err_cleanup;
818                                                   814 
819         /* Release the ring_lock mutex now tha    815         /* Release the ring_lock mutex now that all setup is complete. */
820         mutex_unlock(&ctx->ring_lock);            816         mutex_unlock(&ctx->ring_lock);
821                                                   817 
822         pr_debug("allocated ioctx %p[%ld]: mm=    818         pr_debug("allocated ioctx %p[%ld]: mm=%p mask=0x%x\n",
823                  ctx, ctx->user_id, mm, ctx->n    819                  ctx, ctx->user_id, mm, ctx->nr_events);
824         return ctx;                               820         return ctx;
825                                                   821 
826 err_cleanup:                                      822 err_cleanup:
827         aio_nr_sub(ctx->max_reqs);                823         aio_nr_sub(ctx->max_reqs);
828 err_ctx:                                          824 err_ctx:
829         atomic_set(&ctx->dead, 1);                825         atomic_set(&ctx->dead, 1);
830         if (ctx->mmap_size)                       826         if (ctx->mmap_size)
831                 vm_munmap(ctx->mmap_base, ctx-    827                 vm_munmap(ctx->mmap_base, ctx->mmap_size);
832         aio_free_ring(ctx);                       828         aio_free_ring(ctx);
833 err:                                              829 err:
834         mutex_unlock(&ctx->ring_lock);            830         mutex_unlock(&ctx->ring_lock);
835         free_percpu(ctx->cpu);                    831         free_percpu(ctx->cpu);
836         percpu_ref_exit(&ctx->reqs);              832         percpu_ref_exit(&ctx->reqs);
837         percpu_ref_exit(&ctx->users);             833         percpu_ref_exit(&ctx->users);
838         kmem_cache_free(kioctx_cachep, ctx);      834         kmem_cache_free(kioctx_cachep, ctx);
839         pr_debug("error allocating ioctx %d\n"    835         pr_debug("error allocating ioctx %d\n", err);
840         return ERR_PTR(err);                      836         return ERR_PTR(err);
841 }                                                 837 }
842                                                   838 
843 /* kill_ioctx                                     839 /* kill_ioctx
844  *      Cancels all outstanding aio requests o    840  *      Cancels all outstanding aio requests on an aio context.  Used
845  *      when the processes owning a context ha    841  *      when the processes owning a context have all exited to encourage
846  *      the rapid destruction of the kioctx.      842  *      the rapid destruction of the kioctx.
847  */                                               843  */
848 static int kill_ioctx(struct mm_struct *mm, st    844 static int kill_ioctx(struct mm_struct *mm, struct kioctx *ctx,
849                       struct ctx_rq_wait *wait    845                       struct ctx_rq_wait *wait)
850 {                                                 846 {
851         struct kioctx_table *table;               847         struct kioctx_table *table;
852                                                   848 
853         spin_lock(&mm->ioctx_lock);               849         spin_lock(&mm->ioctx_lock);
854         if (atomic_xchg(&ctx->dead, 1)) {         850         if (atomic_xchg(&ctx->dead, 1)) {
855                 spin_unlock(&mm->ioctx_lock);     851                 spin_unlock(&mm->ioctx_lock);
856                 return -EINVAL;                   852                 return -EINVAL;
857         }                                         853         }
858                                                   854 
859         table = rcu_dereference_raw(mm->ioctx_    855         table = rcu_dereference_raw(mm->ioctx_table);
860         WARN_ON(ctx != rcu_access_pointer(tabl    856         WARN_ON(ctx != rcu_access_pointer(table->table[ctx->id]));
861         RCU_INIT_POINTER(table->table[ctx->id]    857         RCU_INIT_POINTER(table->table[ctx->id], NULL);
862         spin_unlock(&mm->ioctx_lock);             858         spin_unlock(&mm->ioctx_lock);
863                                                   859 
864         /* free_ioctx_reqs() will do the neces    860         /* free_ioctx_reqs() will do the necessary RCU synchronization */
865         wake_up_all(&ctx->wait);                  861         wake_up_all(&ctx->wait);
866                                                   862 
867         /*                                        863         /*
868          * It'd be more correct to do this in     864          * It'd be more correct to do this in free_ioctx(), after all
869          * the outstanding kiocbs have finishe    865          * the outstanding kiocbs have finished - but by then io_destroy
870          * has already returned, so io_setup()    866          * has already returned, so io_setup() could potentially return
871          * -EAGAIN with no ioctxs actually in     867          * -EAGAIN with no ioctxs actually in use (as far as userspace
872          *  could tell).                          868          *  could tell).
873          */                                       869          */
874         aio_nr_sub(ctx->max_reqs);                870         aio_nr_sub(ctx->max_reqs);
875                                                   871 
876         if (ctx->mmap_size)                       872         if (ctx->mmap_size)
877                 vm_munmap(ctx->mmap_base, ctx-    873                 vm_munmap(ctx->mmap_base, ctx->mmap_size);
878                                                   874 
879         ctx->rq_wait = wait;                      875         ctx->rq_wait = wait;
880         percpu_ref_kill(&ctx->users);             876         percpu_ref_kill(&ctx->users);
881         return 0;                                 877         return 0;
882 }                                                 878 }
883                                                   879 
884 /*                                                880 /*
885  * exit_aio: called when the last user of mm g    881  * exit_aio: called when the last user of mm goes away.  At this point, there is
886  * no way for any new requests to be submited     882  * no way for any new requests to be submited or any of the io_* syscalls to be
887  * called on the context.                         883  * called on the context.
888  *                                                884  *
889  * There may be outstanding kiocbs, but free_i    885  * There may be outstanding kiocbs, but free_ioctx() will explicitly wait on
890  * them.                                          886  * them.
891  */                                               887  */
892 void exit_aio(struct mm_struct *mm)               888 void exit_aio(struct mm_struct *mm)
893 {                                                 889 {
894         struct kioctx_table *table = rcu_deref    890         struct kioctx_table *table = rcu_dereference_raw(mm->ioctx_table);
895         struct ctx_rq_wait wait;                  891         struct ctx_rq_wait wait;
896         int i, skipped;                           892         int i, skipped;
897                                                   893 
898         if (!table)                               894         if (!table)
899                 return;                           895                 return;
900                                                   896 
901         atomic_set(&wait.count, table->nr);       897         atomic_set(&wait.count, table->nr);
902         init_completion(&wait.comp);              898         init_completion(&wait.comp);
903                                                   899 
904         skipped = 0;                              900         skipped = 0;
905         for (i = 0; i < table->nr; ++i) {         901         for (i = 0; i < table->nr; ++i) {
906                 struct kioctx *ctx =              902                 struct kioctx *ctx =
907                         rcu_dereference_protec    903                         rcu_dereference_protected(table->table[i], true);
908                                                   904 
909                 if (!ctx) {                       905                 if (!ctx) {
910                         skipped++;                906                         skipped++;
911                         continue;                 907                         continue;
912                 }                                 908                 }
913                                                   909 
914                 /*                                910                 /*
915                  * We don't need to bother wit    911                  * We don't need to bother with munmap() here - exit_mmap(mm)
916                  * is coming and it'll unmap e    912                  * is coming and it'll unmap everything. And we simply can't,
917                  * this is not necessarily our    913                  * this is not necessarily our ->mm.
918                  * Since kill_ioctx() uses non    914                  * Since kill_ioctx() uses non-zero ->mmap_size as indicator
919                  * that it needs to unmap the     915                  * that it needs to unmap the area, just set it to 0.
920                  */                               916                  */
921                 ctx->mmap_size = 0;               917                 ctx->mmap_size = 0;
922                 kill_ioctx(mm, ctx, &wait);       918                 kill_ioctx(mm, ctx, &wait);
923         }                                         919         }
924                                                   920 
925         if (!atomic_sub_and_test(skipped, &wai    921         if (!atomic_sub_and_test(skipped, &wait.count)) {
926                 /* Wait until all IO for the c    922                 /* Wait until all IO for the context are done. */
927                 wait_for_completion(&wait.comp    923                 wait_for_completion(&wait.comp);
928         }                                         924         }
929                                                   925 
930         RCU_INIT_POINTER(mm->ioctx_table, NULL    926         RCU_INIT_POINTER(mm->ioctx_table, NULL);
931         kfree(table);                             927         kfree(table);
932 }                                                 928 }
933                                                   929 
934 static void put_reqs_available(struct kioctx *    930 static void put_reqs_available(struct kioctx *ctx, unsigned nr)
935 {                                                 931 {
936         struct kioctx_cpu *kcpu;                  932         struct kioctx_cpu *kcpu;
937         unsigned long flags;                      933         unsigned long flags;
938                                                   934 
939         local_irq_save(flags);                    935         local_irq_save(flags);
940         kcpu = this_cpu_ptr(ctx->cpu);            936         kcpu = this_cpu_ptr(ctx->cpu);
941         kcpu->reqs_available += nr;               937         kcpu->reqs_available += nr;
942                                                   938 
943         while (kcpu->reqs_available >= ctx->re    939         while (kcpu->reqs_available >= ctx->req_batch * 2) {
944                 kcpu->reqs_available -= ctx->r    940                 kcpu->reqs_available -= ctx->req_batch;
945                 atomic_add(ctx->req_batch, &ct    941                 atomic_add(ctx->req_batch, &ctx->reqs_available);
946         }                                         942         }
947                                                   943 
948         local_irq_restore(flags);                 944         local_irq_restore(flags);
949 }                                                 945 }
950                                                   946 
951 static bool __get_reqs_available(struct kioctx !! 947 static bool get_reqs_available(struct kioctx *ctx)
952 {                                                 948 {
953         struct kioctx_cpu *kcpu;                  949         struct kioctx_cpu *kcpu;
954         bool ret = false;                         950         bool ret = false;
955         unsigned long flags;                      951         unsigned long flags;
956                                                   952 
957         local_irq_save(flags);                    953         local_irq_save(flags);
958         kcpu = this_cpu_ptr(ctx->cpu);            954         kcpu = this_cpu_ptr(ctx->cpu);
959         if (!kcpu->reqs_available) {              955         if (!kcpu->reqs_available) {
960                 int avail = atomic_read(&ctx-> !! 956                 int old, avail = atomic_read(&ctx->reqs_available);
961                                                   957 
962                 do {                              958                 do {
963                         if (avail < ctx->req_b    959                         if (avail < ctx->req_batch)
964                                 goto out;         960                                 goto out;
965                 } while (!atomic_try_cmpxchg(& !! 961 
966                                              & !! 962                         old = avail;
                                                   >> 963                         avail = atomic_cmpxchg(&ctx->reqs_available,
                                                   >> 964                                                avail, avail - ctx->req_batch);
                                                   >> 965                 } while (avail != old);
967                                                   966 
968                 kcpu->reqs_available += ctx->r    967                 kcpu->reqs_available += ctx->req_batch;
969         }                                         968         }
970                                                   969 
971         ret = true;                               970         ret = true;
972         kcpu->reqs_available--;                   971         kcpu->reqs_available--;
973 out:                                              972 out:
974         local_irq_restore(flags);                 973         local_irq_restore(flags);
975         return ret;                               974         return ret;
976 }                                                 975 }
977                                                   976 
978 /* refill_reqs_available                          977 /* refill_reqs_available
979  *      Updates the reqs_available reference c    978  *      Updates the reqs_available reference counts used for tracking the
980  *      number of free slots in the completion    979  *      number of free slots in the completion ring.  This can be called
981  *      from aio_complete() (to optimistically    980  *      from aio_complete() (to optimistically update reqs_available) or
982  *      from aio_get_req() (the we're out of e    981  *      from aio_get_req() (the we're out of events case).  It must be
983  *      called holding ctx->completion_lock.      982  *      called holding ctx->completion_lock.
984  */                                               983  */
985 static void refill_reqs_available(struct kioct    984 static void refill_reqs_available(struct kioctx *ctx, unsigned head,
986                                   unsigned tai    985                                   unsigned tail)
987 {                                                 986 {
988         unsigned events_in_ring, completed;       987         unsigned events_in_ring, completed;
989                                                   988 
990         /* Clamp head since userland can write    989         /* Clamp head since userland can write to it. */
991         head %= ctx->nr_events;                   990         head %= ctx->nr_events;
992         if (head <= tail)                         991         if (head <= tail)
993                 events_in_ring = tail - head;     992                 events_in_ring = tail - head;
994         else                                      993         else
995                 events_in_ring = ctx->nr_event    994                 events_in_ring = ctx->nr_events - (head - tail);
996                                                   995 
997         completed = ctx->completed_events;        996         completed = ctx->completed_events;
998         if (events_in_ring < completed)           997         if (events_in_ring < completed)
999                 completed -= events_in_ring;      998                 completed -= events_in_ring;
1000         else                                     999         else
1001                 completed = 0;                   1000                 completed = 0;
1002                                                  1001 
1003         if (!completed)                          1002         if (!completed)
1004                 return;                          1003                 return;
1005                                                  1004 
1006         ctx->completed_events -= completed;      1005         ctx->completed_events -= completed;
1007         put_reqs_available(ctx, completed);      1006         put_reqs_available(ctx, completed);
1008 }                                                1007 }
1009                                                  1008 
1010 /* user_refill_reqs_available                    1009 /* user_refill_reqs_available
1011  *      Called to refill reqs_available when     1010  *      Called to refill reqs_available when aio_get_req() encounters an
1012  *      out of space in the completion ring.     1011  *      out of space in the completion ring.
1013  */                                              1012  */
1014 static void user_refill_reqs_available(struct    1013 static void user_refill_reqs_available(struct kioctx *ctx)
1015 {                                                1014 {
1016         spin_lock_irq(&ctx->completion_lock);    1015         spin_lock_irq(&ctx->completion_lock);
1017         if (ctx->completed_events) {             1016         if (ctx->completed_events) {
1018                 struct aio_ring *ring;           1017                 struct aio_ring *ring;
1019                 unsigned head;                   1018                 unsigned head;
1020                                                  1019 
1021                 /* Access of ring->head may r    1020                 /* Access of ring->head may race with aio_read_events_ring()
1022                  * here, but that's okay sinc    1021                  * here, but that's okay since whether we read the old version
1023                  * or the new version, and ei    1022                  * or the new version, and either will be valid.  The important
1024                  * part is that head cannot p    1023                  * part is that head cannot pass tail since we prevent
1025                  * aio_complete() from updati    1024                  * aio_complete() from updating tail by holding
1026                  * ctx->completion_lock.  Eve    1025                  * ctx->completion_lock.  Even if head is invalid, the check
1027                  * against ctx->completed_eve    1026                  * against ctx->completed_events below will make sure we do the
1028                  * safe/right thing.             1027                  * safe/right thing.
1029                  */                              1028                  */
1030                 ring = folio_address(ctx->rin !! 1029                 ring = kmap_atomic(ctx->ring_pages[0]);
1031                 head = ring->head;               1030                 head = ring->head;
                                                   >> 1031                 kunmap_atomic(ring);
1032                                                  1032 
1033                 refill_reqs_available(ctx, he    1033                 refill_reqs_available(ctx, head, ctx->tail);
1034         }                                        1034         }
1035                                                  1035 
1036         spin_unlock_irq(&ctx->completion_lock    1036         spin_unlock_irq(&ctx->completion_lock);
1037 }                                                1037 }
1038                                                  1038 
1039 static bool get_reqs_available(struct kioctx  << 
1040 {                                             << 
1041         if (__get_reqs_available(ctx))        << 
1042                 return true;                  << 
1043         user_refill_reqs_available(ctx);      << 
1044         return __get_reqs_available(ctx);     << 
1045 }                                             << 
1046                                               << 
1047 /* aio_get_req                                   1039 /* aio_get_req
1048  *      Allocate a slot for an aio request.      1040  *      Allocate a slot for an aio request.
1049  * Returns NULL if no requests are free.         1041  * Returns NULL if no requests are free.
1050  *                                            << 
1051  * The refcount is initialized to 2 - one for << 
1052  * one for the synchronous code that does thi << 
1053  */                                              1042  */
1054 static inline struct aio_kiocb *aio_get_req(s    1043 static inline struct aio_kiocb *aio_get_req(struct kioctx *ctx)
1055 {                                                1044 {
1056         struct aio_kiocb *req;                   1045         struct aio_kiocb *req;
1057                                                  1046 
1058         req = kmem_cache_alloc(kiocb_cachep,  !! 1047         if (!get_reqs_available(ctx)) {
1059         if (unlikely(!req))                   !! 1048                 user_refill_reqs_available(ctx);
1060                 return NULL;                  !! 1049                 if (!get_reqs_available(ctx))
1061                                               !! 1050                         return NULL;
1062         if (unlikely(!get_reqs_available(ctx) << 
1063                 kmem_cache_free(kiocb_cachep, << 
1064                 return NULL;                  << 
1065         }                                        1051         }
1066                                                  1052 
                                                   >> 1053         req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL|__GFP_ZERO);
                                                   >> 1054         if (unlikely(!req))
                                                   >> 1055                 goto out_put;
                                                   >> 1056 
1067         percpu_ref_get(&ctx->reqs);              1057         percpu_ref_get(&ctx->reqs);
                                                   >> 1058 
1068         req->ki_ctx = ctx;                       1059         req->ki_ctx = ctx;
1069         INIT_LIST_HEAD(&req->ki_list);        << 
1070         refcount_set(&req->ki_refcnt, 2);     << 
1071         req->ki_eventfd = NULL;               << 
1072         return req;                              1060         return req;
                                                   >> 1061 out_put:
                                                   >> 1062         put_reqs_available(ctx, 1);
                                                   >> 1063         return NULL;
                                                   >> 1064 }
                                                   >> 1065 
                                                   >> 1066 static void kiocb_free(struct aio_kiocb *req)
                                                   >> 1067 {
                                                   >> 1068         if (req->common.ki_filp)
                                                   >> 1069                 fput(req->common.ki_filp);
                                                   >> 1070         if (req->ki_eventfd != NULL)
                                                   >> 1071                 eventfd_ctx_put(req->ki_eventfd);
                                                   >> 1072         kmem_cache_free(kiocb_cachep, req);
1073 }                                                1073 }
1074                                                  1074 
1075 static struct kioctx *lookup_ioctx(unsigned l    1075 static struct kioctx *lookup_ioctx(unsigned long ctx_id)
1076 {                                                1076 {
1077         struct aio_ring __user *ring  = (void    1077         struct aio_ring __user *ring  = (void __user *)ctx_id;
1078         struct mm_struct *mm = current->mm;      1078         struct mm_struct *mm = current->mm;
1079         struct kioctx *ctx, *ret = NULL;         1079         struct kioctx *ctx, *ret = NULL;
1080         struct kioctx_table *table;              1080         struct kioctx_table *table;
1081         unsigned id;                             1081         unsigned id;
1082                                                  1082 
1083         if (get_user(id, &ring->id))             1083         if (get_user(id, &ring->id))
1084                 return NULL;                     1084                 return NULL;
1085                                                  1085 
1086         rcu_read_lock();                         1086         rcu_read_lock();
1087         table = rcu_dereference(mm->ioctx_tab    1087         table = rcu_dereference(mm->ioctx_table);
1088                                                  1088 
1089         if (!table || id >= table->nr)           1089         if (!table || id >= table->nr)
1090                 goto out;                        1090                 goto out;
1091                                                  1091 
1092         id = array_index_nospec(id, table->nr    1092         id = array_index_nospec(id, table->nr);
1093         ctx = rcu_dereference(table->table[id    1093         ctx = rcu_dereference(table->table[id]);
1094         if (ctx && ctx->user_id == ctx_id) {     1094         if (ctx && ctx->user_id == ctx_id) {
1095                 if (percpu_ref_tryget_live(&c    1095                 if (percpu_ref_tryget_live(&ctx->users))
1096                         ret = ctx;               1096                         ret = ctx;
1097         }                                        1097         }
1098 out:                                             1098 out:
1099         rcu_read_unlock();                       1099         rcu_read_unlock();
1100         return ret;                              1100         return ret;
1101 }                                                1101 }
1102                                                  1102 
1103 static inline void iocb_destroy(struct aio_ki << 
1104 {                                             << 
1105         if (iocb->ki_eventfd)                 << 
1106                 eventfd_ctx_put(iocb->ki_even << 
1107         if (iocb->ki_filp)                    << 
1108                 fput(iocb->ki_filp);          << 
1109         percpu_ref_put(&iocb->ki_ctx->reqs);  << 
1110         kmem_cache_free(kiocb_cachep, iocb);  << 
1111 }                                             << 
1112                                               << 
1113 struct aio_waiter {                           << 
1114         struct wait_queue_entry w;            << 
1115         size_t                  min_nr;       << 
1116 };                                            << 
1117                                               << 
1118 /* aio_complete                                  1103 /* aio_complete
1119  *      Called when the io request on the giv    1104  *      Called when the io request on the given iocb is complete.
1120  */                                              1105  */
1121 static void aio_complete(struct aio_kiocb *io !! 1106 static void aio_complete(struct kiocb *kiocb, long res, long res2)
1122 {                                                1107 {
                                                   >> 1108         struct aio_kiocb *iocb = container_of(kiocb, struct aio_kiocb, common);
1123         struct kioctx   *ctx = iocb->ki_ctx;     1109         struct kioctx   *ctx = iocb->ki_ctx;
1124         struct aio_ring *ring;                   1110         struct aio_ring *ring;
1125         struct io_event *ev_page, *event;        1111         struct io_event *ev_page, *event;
1126         unsigned tail, pos, head, avail;      !! 1112         unsigned tail, pos, head;
1127         unsigned long   flags;                   1113         unsigned long   flags;
1128                                                  1114 
                                                   >> 1115         if (kiocb->ki_flags & IOCB_WRITE) {
                                                   >> 1116                 struct file *file = kiocb->ki_filp;
                                                   >> 1117 
                                                   >> 1118                 /*
                                                   >> 1119                  * Tell lockdep we inherited freeze protection from submission
                                                   >> 1120                  * thread.
                                                   >> 1121                  */
                                                   >> 1122                 if (S_ISREG(file_inode(file)->i_mode))
                                                   >> 1123                         __sb_writers_acquired(file_inode(file)->i_sb, SB_FREEZE_WRITE);
                                                   >> 1124                 file_end_write(file);
                                                   >> 1125         }
                                                   >> 1126 
                                                   >> 1127         /*
                                                   >> 1128          * Special case handling for sync iocbs:
                                                   >> 1129          *  - events go directly into the iocb for fast handling
                                                   >> 1130          *  - the sync task with the iocb in its stack holds the single iocb
                                                   >> 1131          *    ref, no other paths have a way to get another ref
                                                   >> 1132          *  - the sync task helpfully left a reference to itself in the iocb
                                                   >> 1133          */
                                                   >> 1134         BUG_ON(is_sync_kiocb(kiocb));
                                                   >> 1135 
                                                   >> 1136         if (iocb->ki_list.next) {
                                                   >> 1137                 unsigned long flags;
                                                   >> 1138 
                                                   >> 1139                 spin_lock_irqsave(&ctx->ctx_lock, flags);
                                                   >> 1140                 list_del(&iocb->ki_list);
                                                   >> 1141                 spin_unlock_irqrestore(&ctx->ctx_lock, flags);
                                                   >> 1142         }
                                                   >> 1143 
1129         /*                                       1144         /*
1130          * Add a completion event to the ring    1145          * Add a completion event to the ring buffer. Must be done holding
1131          * ctx->completion_lock to prevent ot    1146          * ctx->completion_lock to prevent other code from messing with the tail
1132          * pointer since we might be called f    1147          * pointer since we might be called from irq context.
1133          */                                      1148          */
1134         spin_lock_irqsave(&ctx->completion_lo    1149         spin_lock_irqsave(&ctx->completion_lock, flags);
1135                                                  1150 
1136         tail = ctx->tail;                        1151         tail = ctx->tail;
1137         pos = tail + AIO_EVENTS_OFFSET;          1152         pos = tail + AIO_EVENTS_OFFSET;
1138                                                  1153 
1139         if (++tail >= ctx->nr_events)            1154         if (++tail >= ctx->nr_events)
1140                 tail = 0;                        1155                 tail = 0;
1141                                                  1156 
1142         ev_page = folio_address(ctx->ring_fol !! 1157         ev_page = kmap_atomic(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]);
1143         event = ev_page + pos % AIO_EVENTS_PE    1158         event = ev_page + pos % AIO_EVENTS_PER_PAGE;
1144                                                  1159 
1145         *event = iocb->ki_res;                !! 1160         event->obj = (u64)(unsigned long)iocb->ki_user_iocb;
1146                                               !! 1161         event->data = iocb->ki_user_data;
1147         flush_dcache_folio(ctx->ring_folios[p !! 1162         event->res = res;
1148                                               !! 1163         event->res2 = res2;
1149         pr_debug("%p[%u]: %p: %p %Lx %Lx %Lx\ !! 1164 
1150                  (void __user *)(unsigned lon !! 1165         kunmap_atomic(ev_page);
1151                  iocb->ki_res.data, iocb->ki_ !! 1166         flush_dcache_page(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]);
                                                   >> 1167 
                                                   >> 1168         pr_debug("%p[%u]: %p: %p %Lx %lx %lx\n",
                                                   >> 1169                  ctx, tail, iocb, iocb->ki_user_iocb, iocb->ki_user_data,
                                                   >> 1170                  res, res2);
1152                                                  1171 
1153         /* after flagging the request as done    1172         /* after flagging the request as done, we
1154          * must never even look at it again      1173          * must never even look at it again
1155          */                                      1174          */
1156         smp_wmb();      /* make event visible    1175         smp_wmb();      /* make event visible before updating tail */
1157                                                  1176 
1158         ctx->tail = tail;                        1177         ctx->tail = tail;
1159                                                  1178 
1160         ring = folio_address(ctx->ring_folios !! 1179         ring = kmap_atomic(ctx->ring_pages[0]);
1161         head = ring->head;                       1180         head = ring->head;
1162         ring->tail = tail;                       1181         ring->tail = tail;
1163         flush_dcache_folio(ctx->ring_folios[0 !! 1182         kunmap_atomic(ring);
                                                   >> 1183         flush_dcache_page(ctx->ring_pages[0]);
1164                                                  1184 
1165         ctx->completed_events++;                 1185         ctx->completed_events++;
1166         if (ctx->completed_events > 1)           1186         if (ctx->completed_events > 1)
1167                 refill_reqs_available(ctx, he    1187                 refill_reqs_available(ctx, head, tail);
1168                                               << 
1169         avail = tail > head                   << 
1170                 ? tail - head                 << 
1171                 : tail + ctx->nr_events - hea << 
1172         spin_unlock_irqrestore(&ctx->completi    1188         spin_unlock_irqrestore(&ctx->completion_lock, flags);
1173                                                  1189 
1174         pr_debug("added to ring %p at [%u]\n"    1190         pr_debug("added to ring %p at [%u]\n", iocb, tail);
1175                                                  1191 
1176         /*                                       1192         /*
1177          * Check if the user asked us to deli    1193          * Check if the user asked us to deliver the result through an
1178          * eventfd. The eventfd_signal() func    1194          * eventfd. The eventfd_signal() function is safe to be called
1179          * from IRQ context.                     1195          * from IRQ context.
1180          */                                      1196          */
1181         if (iocb->ki_eventfd)                 !! 1197         if (iocb->ki_eventfd != NULL)
1182                 eventfd_signal(iocb->ki_event !! 1198                 eventfd_signal(iocb->ki_eventfd, 1);
                                                   >> 1199 
                                                   >> 1200         /* everything turned out well, dispose of the aiocb. */
                                                   >> 1201         kiocb_free(iocb);
1183                                                  1202 
1184         /*                                       1203         /*
1185          * We have to order our ring_info tai    1204          * We have to order our ring_info tail store above and test
1186          * of the wait list below outside the    1205          * of the wait list below outside the wait lock.  This is
1187          * like in wake_up_bit() where cleari    1206          * like in wake_up_bit() where clearing a bit has to be
1188          * ordered with the unlocked test.       1207          * ordered with the unlocked test.
1189          */                                      1208          */
1190         smp_mb();                                1209         smp_mb();
1191                                                  1210 
1192         if (waitqueue_active(&ctx->wait)) {   !! 1211         if (waitqueue_active(&ctx->wait))
1193                 struct aio_waiter *curr, *nex !! 1212                 wake_up(&ctx->wait);
1194                 unsigned long flags;          << 
1195                                                  1213 
1196                 spin_lock_irqsave(&ctx->wait. !! 1214         percpu_ref_put(&ctx->reqs);
1197                 list_for_each_entry_safe(curr << 
1198                         if (avail >= curr->mi << 
1199                                 wake_up_proce << 
1200                                 list_del_init << 
1201                         }                     << 
1202                 spin_unlock_irqrestore(&ctx-> << 
1203         }                                     << 
1204 }                                             << 
1205                                               << 
1206 static inline void iocb_put(struct aio_kiocb  << 
1207 {                                             << 
1208         if (refcount_dec_and_test(&iocb->ki_r << 
1209                 aio_complete(iocb);           << 
1210                 iocb_destroy(iocb);           << 
1211         }                                     << 
1212 }                                                1215 }
1213                                                  1216 
1214 /* aio_read_events_ring                          1217 /* aio_read_events_ring
1215  *      Pull an event off of the ioctx's even    1218  *      Pull an event off of the ioctx's event ring.  Returns the number of
1216  *      events fetched                           1219  *      events fetched
1217  */                                              1220  */
1218 static long aio_read_events_ring(struct kioct    1221 static long aio_read_events_ring(struct kioctx *ctx,
1219                                  struct io_ev    1222                                  struct io_event __user *event, long nr)
1220 {                                                1223 {
1221         struct aio_ring *ring;                   1224         struct aio_ring *ring;
1222         unsigned head, tail, pos;                1225         unsigned head, tail, pos;
1223         long ret = 0;                            1226         long ret = 0;
1224         int copy_ret;                            1227         int copy_ret;
1225                                                  1228 
1226         /*                                       1229         /*
1227          * The mutex can block and wake us up    1230          * The mutex can block and wake us up and that will cause
1228          * wait_event_interruptible_hrtimeout    1231          * wait_event_interruptible_hrtimeout() to schedule without sleeping
1229          * and repeat. This should be rare en    1232          * and repeat. This should be rare enough that it doesn't cause
1230          * peformance issues. See the comment    1233          * peformance issues. See the comment in read_events() for more detail.
1231          */                                      1234          */
1232         sched_annotate_sleep();                  1235         sched_annotate_sleep();
1233         mutex_lock(&ctx->ring_lock);             1236         mutex_lock(&ctx->ring_lock);
1234                                                  1237 
1235         /* Access to ->ring_folios here is pr !! 1238         /* Access to ->ring_pages here is protected by ctx->ring_lock. */
1236         ring = folio_address(ctx->ring_folios !! 1239         ring = kmap_atomic(ctx->ring_pages[0]);
1237         head = ring->head;                       1240         head = ring->head;
1238         tail = ring->tail;                       1241         tail = ring->tail;
                                                   >> 1242         kunmap_atomic(ring);
1239                                                  1243 
1240         /*                                       1244         /*
1241          * Ensure that once we've read the cu    1245          * Ensure that once we've read the current tail pointer, that
1242          * we also see the events that were s    1246          * we also see the events that were stored up to the tail.
1243          */                                      1247          */
1244         smp_rmb();                               1248         smp_rmb();
1245                                                  1249 
1246         pr_debug("h%u t%u m%u\n", head, tail,    1250         pr_debug("h%u t%u m%u\n", head, tail, ctx->nr_events);
1247                                                  1251 
1248         if (head == tail)                        1252         if (head == tail)
1249                 goto out;                        1253                 goto out;
1250                                                  1254 
1251         head %= ctx->nr_events;                  1255         head %= ctx->nr_events;
1252         tail %= ctx->nr_events;                  1256         tail %= ctx->nr_events;
1253                                                  1257 
1254         while (ret < nr) {                       1258         while (ret < nr) {
1255                 long avail;                      1259                 long avail;
1256                 struct io_event *ev;             1260                 struct io_event *ev;
1257                 struct folio *folio;          !! 1261                 struct page *page;
1258                                                  1262 
1259                 avail = (head <= tail ?  tail    1263                 avail = (head <= tail ?  tail : ctx->nr_events) - head;
1260                 if (head == tail)                1264                 if (head == tail)
1261                         break;                   1265                         break;
1262                                                  1266 
                                                   >> 1267                 avail = min(avail, nr - ret);
                                                   >> 1268                 avail = min_t(long, avail, AIO_EVENTS_PER_PAGE -
                                                   >> 1269                             ((head + AIO_EVENTS_OFFSET) % AIO_EVENTS_PER_PAGE));
                                                   >> 1270 
1263                 pos = head + AIO_EVENTS_OFFSE    1271                 pos = head + AIO_EVENTS_OFFSET;
1264                 folio = ctx->ring_folios[pos  !! 1272                 page = ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE];
1265                 pos %= AIO_EVENTS_PER_PAGE;      1273                 pos %= AIO_EVENTS_PER_PAGE;
1266                                                  1274 
1267                 avail = min(avail, nr - ret); !! 1275                 ev = kmap(page);
1268                 avail = min_t(long, avail, AI << 
1269                                               << 
1270                 ev = folio_address(folio);    << 
1271                 copy_ret = copy_to_user(event    1276                 copy_ret = copy_to_user(event + ret, ev + pos,
1272                                         sizeo    1277                                         sizeof(*ev) * avail);
                                                   >> 1278                 kunmap(page);
1273                                                  1279 
1274                 if (unlikely(copy_ret)) {        1280                 if (unlikely(copy_ret)) {
1275                         ret = -EFAULT;           1281                         ret = -EFAULT;
1276                         goto out;                1282                         goto out;
1277                 }                                1283                 }
1278                                                  1284 
1279                 ret += avail;                    1285                 ret += avail;
1280                 head += avail;                   1286                 head += avail;
1281                 head %= ctx->nr_events;          1287                 head %= ctx->nr_events;
1282         }                                        1288         }
1283                                                  1289 
1284         ring = folio_address(ctx->ring_folios !! 1290         ring = kmap_atomic(ctx->ring_pages[0]);
1285         ring->head = head;                       1291         ring->head = head;
1286         flush_dcache_folio(ctx->ring_folios[0 !! 1292         kunmap_atomic(ring);
                                                   >> 1293         flush_dcache_page(ctx->ring_pages[0]);
1287                                                  1294 
1288         pr_debug("%li  h%u t%u\n", ret, head,    1295         pr_debug("%li  h%u t%u\n", ret, head, tail);
1289 out:                                             1296 out:
1290         mutex_unlock(&ctx->ring_lock);           1297         mutex_unlock(&ctx->ring_lock);
1291                                                  1298 
1292         return ret;                              1299         return ret;
1293 }                                                1300 }
1294                                                  1301 
1295 static bool aio_read_events(struct kioctx *ct    1302 static bool aio_read_events(struct kioctx *ctx, long min_nr, long nr,
1296                             struct io_event _    1303                             struct io_event __user *event, long *i)
1297 {                                                1304 {
1298         long ret = aio_read_events_ring(ctx,     1305         long ret = aio_read_events_ring(ctx, event + *i, nr - *i);
1299                                                  1306 
1300         if (ret > 0)                             1307         if (ret > 0)
1301                 *i += ret;                       1308                 *i += ret;
1302                                                  1309 
1303         if (unlikely(atomic_read(&ctx->dead))    1310         if (unlikely(atomic_read(&ctx->dead)))
1304                 ret = -EINVAL;                   1311                 ret = -EINVAL;
1305                                                  1312 
1306         if (!*i)                                 1313         if (!*i)
1307                 *i = ret;                        1314                 *i = ret;
1308                                                  1315 
1309         return ret < 0 || *i >= min_nr;          1316         return ret < 0 || *i >= min_nr;
1310 }                                                1317 }
1311                                                  1318 
1312 static long read_events(struct kioctx *ctx, l    1319 static long read_events(struct kioctx *ctx, long min_nr, long nr,
1313                         struct io_event __use    1320                         struct io_event __user *event,
1314                         ktime_t until)        !! 1321                         struct timespec __user *timeout)
1315 {                                                1322 {
1316         struct hrtimer_sleeper  t;            !! 1323         ktime_t until = KTIME_MAX;
1317         struct aio_waiter       w;            !! 1324         long ret = 0;
1318         long ret = 0, ret2 = 0;               !! 1325 
                                                   >> 1326         if (timeout) {
                                                   >> 1327                 struct timespec ts;
                                                   >> 1328 
                                                   >> 1329                 if (unlikely(copy_from_user(&ts, timeout, sizeof(ts))))
                                                   >> 1330                         return -EFAULT;
                                                   >> 1331 
                                                   >> 1332                 until = timespec_to_ktime(ts);
                                                   >> 1333         }
1319                                                  1334 
1320         /*                                       1335         /*
1321          * Note that aio_read_events() is bei    1336          * Note that aio_read_events() is being called as the conditional - i.e.
1322          * we're calling it after prepare_to_    1337          * we're calling it after prepare_to_wait() has set task state to
1323          * TASK_INTERRUPTIBLE.                   1338          * TASK_INTERRUPTIBLE.
1324          *                                       1339          *
1325          * But aio_read_events() can block, a    1340          * But aio_read_events() can block, and if it blocks it's going to flip
1326          * the task state back to TASK_RUNNIN    1341          * the task state back to TASK_RUNNING.
1327          *                                       1342          *
1328          * This should be ok, provided it doe    1343          * This should be ok, provided it doesn't flip the state back to
1329          * TASK_RUNNING and return 0 too much    1344          * TASK_RUNNING and return 0 too much - that causes us to spin. That
1330          * will only happen if the mutex_lock    1345          * will only happen if the mutex_lock() call blocks, and we then find
1331          * the ringbuffer empty. So in practi    1346          * the ringbuffer empty. So in practice we should be ok, but it's
1332          * something to be aware of when touc    1347          * something to be aware of when touching this code.
1333          */                                      1348          */
1334         aio_read_events(ctx, min_nr, nr, even !! 1349         if (until == 0)
1335         if (until == 0 || ret < 0 || ret >= m !! 1350                 aio_read_events(ctx, min_nr, nr, event, &ret);
1336                 return ret;                   !! 1351         else
1337                                               !! 1352                 wait_event_interruptible_hrtimeout(ctx->wait,
1338         hrtimer_init_sleeper_on_stack(&t, CLO !! 1353                                 aio_read_events(ctx, min_nr, nr, event, &ret),
1339         if (until != KTIME_MAX) {             !! 1354                                 until);
1340                 hrtimer_set_expires_range_ns( << 
1341                 hrtimer_sleeper_start_expires << 
1342         }                                     << 
1343                                               << 
1344         init_wait(&w.w);                      << 
1345                                               << 
1346         while (1) {                           << 
1347                 unsigned long nr_got = ret;   << 
1348                                               << 
1349                 w.min_nr = min_nr - ret;      << 
1350                                               << 
1351                 ret2 = prepare_to_wait_event( << 
1352                 if (!ret2 && !t.task)         << 
1353                         ret2 = -ETIME;        << 
1354                                               << 
1355                 if (aio_read_events(ctx, min_ << 
1356                         break;                << 
1357                                               << 
1358                 if (nr_got == ret)            << 
1359                         schedule();           << 
1360         }                                     << 
1361                                                  1355 
1362         finish_wait(&ctx->wait, &w.w);        !! 1356         if (!ret && signal_pending(current))
1363         hrtimer_cancel(&t.timer);             !! 1357                 ret = -EINTR;
1364         destroy_hrtimer_on_stack(&t.timer);   << 
1365                                                  1358 
1366         return ret;                              1359         return ret;
1367 }                                                1360 }
1368                                                  1361 
1369 /* sys_io_setup:                                 1362 /* sys_io_setup:
1370  *      Create an aio_context capable of rece    1363  *      Create an aio_context capable of receiving at least nr_events.
1371  *      ctxp must not point to an aio_context    1364  *      ctxp must not point to an aio_context that already exists, and
1372  *      must be initialized to 0 prior to the    1365  *      must be initialized to 0 prior to the call.  On successful
1373  *      creation of the aio_context, *ctxp is    1366  *      creation of the aio_context, *ctxp is filled in with the resulting 
1374  *      handle.  May fail with -EINVAL if *ct    1367  *      handle.  May fail with -EINVAL if *ctxp is not initialized,
1375  *      if the specified nr_events exceeds in    1368  *      if the specified nr_events exceeds internal limits.  May fail 
1376  *      with -EAGAIN if the specified nr_even    1369  *      with -EAGAIN if the specified nr_events exceeds the user's limit 
1377  *      of available events.  May fail with -    1370  *      of available events.  May fail with -ENOMEM if insufficient kernel
1378  *      resources are available.  May fail wi    1371  *      resources are available.  May fail with -EFAULT if an invalid
1379  *      pointer is passed for ctxp.  Will fai    1372  *      pointer is passed for ctxp.  Will fail with -ENOSYS if not
1380  *      implemented.                             1373  *      implemented.
1381  */                                              1374  */
1382 SYSCALL_DEFINE2(io_setup, unsigned, nr_events    1375 SYSCALL_DEFINE2(io_setup, unsigned, nr_events, aio_context_t __user *, ctxp)
1383 {                                                1376 {
1384         struct kioctx *ioctx = NULL;             1377         struct kioctx *ioctx = NULL;
1385         unsigned long ctx;                       1378         unsigned long ctx;
1386         long ret;                                1379         long ret;
1387                                                  1380 
1388         ret = get_user(ctx, ctxp);               1381         ret = get_user(ctx, ctxp);
1389         if (unlikely(ret))                       1382         if (unlikely(ret))
1390                 goto out;                        1383                 goto out;
1391                                                  1384 
1392         ret = -EINVAL;                           1385         ret = -EINVAL;
1393         if (unlikely(ctx || nr_events == 0))     1386         if (unlikely(ctx || nr_events == 0)) {
1394                 pr_debug("EINVAL: ctx %lu nr_    1387                 pr_debug("EINVAL: ctx %lu nr_events %u\n",
1395                          ctx, nr_events);        1388                          ctx, nr_events);
1396                 goto out;                        1389                 goto out;
1397         }                                        1390         }
1398                                                  1391 
1399         ioctx = ioctx_alloc(nr_events);          1392         ioctx = ioctx_alloc(nr_events);
1400         ret = PTR_ERR(ioctx);                    1393         ret = PTR_ERR(ioctx);
1401         if (!IS_ERR(ioctx)) {                    1394         if (!IS_ERR(ioctx)) {
1402                 ret = put_user(ioctx->user_id    1395                 ret = put_user(ioctx->user_id, ctxp);
1403                 if (ret)                         1396                 if (ret)
1404                         kill_ioctx(current->m    1397                         kill_ioctx(current->mm, ioctx, NULL);
1405                 percpu_ref_put(&ioctx->users)    1398                 percpu_ref_put(&ioctx->users);
1406         }                                        1399         }
1407                                                  1400 
1408 out:                                             1401 out:
1409         return ret;                              1402         return ret;
1410 }                                                1403 }
1411                                                  1404 
1412 #ifdef CONFIG_COMPAT                             1405 #ifdef CONFIG_COMPAT
1413 COMPAT_SYSCALL_DEFINE2(io_setup, unsigned, nr    1406 COMPAT_SYSCALL_DEFINE2(io_setup, unsigned, nr_events, u32 __user *, ctx32p)
1414 {                                                1407 {
1415         struct kioctx *ioctx = NULL;             1408         struct kioctx *ioctx = NULL;
1416         unsigned long ctx;                       1409         unsigned long ctx;
1417         long ret;                                1410         long ret;
1418                                                  1411 
1419         ret = get_user(ctx, ctx32p);             1412         ret = get_user(ctx, ctx32p);
1420         if (unlikely(ret))                       1413         if (unlikely(ret))
1421                 goto out;                        1414                 goto out;
1422                                                  1415 
1423         ret = -EINVAL;                           1416         ret = -EINVAL;
1424         if (unlikely(ctx || nr_events == 0))     1417         if (unlikely(ctx || nr_events == 0)) {
1425                 pr_debug("EINVAL: ctx %lu nr_    1418                 pr_debug("EINVAL: ctx %lu nr_events %u\n",
1426                          ctx, nr_events);        1419                          ctx, nr_events);
1427                 goto out;                        1420                 goto out;
1428         }                                        1421         }
1429                                                  1422 
1430         ioctx = ioctx_alloc(nr_events);          1423         ioctx = ioctx_alloc(nr_events);
1431         ret = PTR_ERR(ioctx);                    1424         ret = PTR_ERR(ioctx);
1432         if (!IS_ERR(ioctx)) {                    1425         if (!IS_ERR(ioctx)) {
1433                 /* truncating is ok because i    1426                 /* truncating is ok because it's a user address */
1434                 ret = put_user((u32)ioctx->us    1427                 ret = put_user((u32)ioctx->user_id, ctx32p);
1435                 if (ret)                         1428                 if (ret)
1436                         kill_ioctx(current->m    1429                         kill_ioctx(current->mm, ioctx, NULL);
1437                 percpu_ref_put(&ioctx->users)    1430                 percpu_ref_put(&ioctx->users);
1438         }                                        1431         }
1439                                                  1432 
1440 out:                                             1433 out:
1441         return ret;                              1434         return ret;
1442 }                                                1435 }
1443 #endif                                           1436 #endif
1444                                                  1437 
1445 /* sys_io_destroy:                               1438 /* sys_io_destroy:
1446  *      Destroy the aio_context specified.  M    1439  *      Destroy the aio_context specified.  May cancel any outstanding 
1447  *      AIOs and block on completion.  Will f    1440  *      AIOs and block on completion.  Will fail with -ENOSYS if not
1448  *      implemented.  May fail with -EINVAL i    1441  *      implemented.  May fail with -EINVAL if the context pointed to
1449  *      is invalid.                              1442  *      is invalid.
1450  */                                              1443  */
1451 SYSCALL_DEFINE1(io_destroy, aio_context_t, ct    1444 SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx)
1452 {                                                1445 {
1453         struct kioctx *ioctx = lookup_ioctx(c    1446         struct kioctx *ioctx = lookup_ioctx(ctx);
1454         if (likely(NULL != ioctx)) {             1447         if (likely(NULL != ioctx)) {
1455                 struct ctx_rq_wait wait;         1448                 struct ctx_rq_wait wait;
1456                 int ret;                         1449                 int ret;
1457                                                  1450 
1458                 init_completion(&wait.comp);     1451                 init_completion(&wait.comp);
1459                 atomic_set(&wait.count, 1);      1452                 atomic_set(&wait.count, 1);
1460                                                  1453 
1461                 /* Pass requests_done to kill    1454                 /* Pass requests_done to kill_ioctx() where it can be set
1462                  * in a thread-safe way. If w    1455                  * in a thread-safe way. If we try to set it here then we have
1463                  * a race condition if two io    1456                  * a race condition if two io_destroy() called simultaneously.
1464                  */                              1457                  */
1465                 ret = kill_ioctx(current->mm,    1458                 ret = kill_ioctx(current->mm, ioctx, &wait);
1466                 percpu_ref_put(&ioctx->users)    1459                 percpu_ref_put(&ioctx->users);
1467                                                  1460 
1468                 /* Wait until all IO for the     1461                 /* Wait until all IO for the context are done. Otherwise kernel
1469                  * keep using user-space buff    1462                  * keep using user-space buffers even if user thinks the context
1470                  * is destroyed.                 1463                  * is destroyed.
1471                  */                              1464                  */
1472                 if (!ret)                        1465                 if (!ret)
1473                         wait_for_completion(&    1466                         wait_for_completion(&wait.comp);
1474                                                  1467 
1475                 return ret;                      1468                 return ret;
1476         }                                        1469         }
1477         pr_debug("EINVAL: invalid context id\    1470         pr_debug("EINVAL: invalid context id\n");
1478         return -EINVAL;                          1471         return -EINVAL;
1479 }                                                1472 }
1480                                                  1473 
1481 static void aio_remove_iocb(struct aio_kiocb  !! 1474 static int aio_setup_rw(int rw, struct iocb *iocb, struct iovec **iovec,
1482 {                                             !! 1475                 bool vectored, bool compat, struct iov_iter *iter)
1483         struct kioctx *ctx = iocb->ki_ctx;    << 
1484         unsigned long flags;                  << 
1485                                               << 
1486         spin_lock_irqsave(&ctx->ctx_lock, fla << 
1487         list_del(&iocb->ki_list);             << 
1488         spin_unlock_irqrestore(&ctx->ctx_lock << 
1489 }                                             << 
1490                                               << 
1491 static void aio_complete_rw(struct kiocb *kio << 
1492 {                                             << 
1493         struct aio_kiocb *iocb = container_of << 
1494                                               << 
1495         if (!list_empty_careful(&iocb->ki_lis << 
1496                 aio_remove_iocb(iocb);        << 
1497                                               << 
1498         if (kiocb->ki_flags & IOCB_WRITE) {   << 
1499                 struct inode *inode = file_in << 
1500                                               << 
1501                 if (S_ISREG(inode->i_mode))   << 
1502                         kiocb_end_write(kiocb << 
1503         }                                     << 
1504                                               << 
1505         iocb->ki_res.res = res;               << 
1506         iocb->ki_res.res2 = 0;                << 
1507         iocb_put(iocb);                       << 
1508 }                                             << 
1509                                               << 
1510 static int aio_prep_rw(struct kiocb *req, con << 
1511 {                                             << 
1512         int ret;                              << 
1513                                               << 
1514         req->ki_complete = aio_complete_rw;   << 
1515         req->private = NULL;                  << 
1516         req->ki_pos = iocb->aio_offset;       << 
1517         req->ki_flags = req->ki_filp->f_iocb_ << 
1518         if (iocb->aio_flags & IOCB_FLAG_RESFD << 
1519                 req->ki_flags |= IOCB_EVENTFD << 
1520         if (iocb->aio_flags & IOCB_FLAG_IOPRI << 
1521                 /*                            << 
1522                  * If the IOCB_FLAG_IOPRIO fl << 
1523                  * aio_reqprio is interpreted << 
1524                  * class and priority.        << 
1525                  */                           << 
1526                 ret = ioprio_check_cap(iocb-> << 
1527                 if (ret) {                    << 
1528                         pr_debug("aio ioprio  << 
1529                         return ret;           << 
1530                 }                             << 
1531                                               << 
1532                 req->ki_ioprio = iocb->aio_re << 
1533         } else                                << 
1534                 req->ki_ioprio = get_current_ << 
1535                                               << 
1536         ret = kiocb_set_rw_flags(req, iocb->a << 
1537         if (unlikely(ret))                    << 
1538                 return ret;                   << 
1539                                               << 
1540         req->ki_flags &= ~IOCB_HIPRI; /* no o << 
1541         return 0;                             << 
1542 }                                             << 
1543                                               << 
1544 static ssize_t aio_setup_rw(int rw, const str << 
1545                 struct iovec **iovec, bool ve << 
1546                 struct iov_iter *iter)        << 
1547 {                                                1476 {
1548         void __user *buf = (void __user *)(ui    1477         void __user *buf = (void __user *)(uintptr_t)iocb->aio_buf;
1549         size_t len = iocb->aio_nbytes;           1478         size_t len = iocb->aio_nbytes;
1550                                                  1479 
1551         if (!vectored) {                         1480         if (!vectored) {
1552                 ssize_t ret = import_ubuf(rw, !! 1481                 ssize_t ret = import_single_range(rw, buf, len, *iovec, iter);
1553                 *iovec = NULL;                   1482                 *iovec = NULL;
1554                 return ret;                      1483                 return ret;
1555         }                                        1484         }
1556                                               !! 1485 #ifdef CONFIG_COMPAT
1557         return __import_iovec(rw, buf, len, U !! 1486         if (compat)
                                                   >> 1487                 return compat_import_iovec(rw, buf, len, UIO_FASTIOV, iovec,
                                                   >> 1488                                 iter);
                                                   >> 1489 #endif
                                                   >> 1490         return import_iovec(rw, buf, len, UIO_FASTIOV, iovec, iter);
1558 }                                                1491 }
1559                                                  1492 
1560 static inline void aio_rw_done(struct kiocb * !! 1493 static inline ssize_t aio_ret(struct kiocb *req, ssize_t ret)
1561 {                                                1494 {
1562         switch (ret) {                           1495         switch (ret) {
1563         case -EIOCBQUEUED:                       1496         case -EIOCBQUEUED:
1564                 break;                        !! 1497                 return ret;
1565         case -ERESTARTSYS:                       1498         case -ERESTARTSYS:
1566         case -ERESTARTNOINTR:                    1499         case -ERESTARTNOINTR:
1567         case -ERESTARTNOHAND:                    1500         case -ERESTARTNOHAND:
1568         case -ERESTART_RESTARTBLOCK:             1501         case -ERESTART_RESTARTBLOCK:
1569                 /*                               1502                 /*
1570                  * There's no easy way to res    1503                  * There's no easy way to restart the syscall since other AIO's
1571                  * may be already running. Ju    1504                  * may be already running. Just fail this IO with EINTR.
1572                  */                              1505                  */
1573                 ret = -EINTR;                    1506                 ret = -EINTR;
1574                 fallthrough;                  !! 1507                 /*FALLTHRU*/
1575         default:                                 1508         default:
1576                 req->ki_complete(req, ret);   !! 1509                 aio_complete(req, ret, 0);
                                                   >> 1510                 return 0;
1577         }                                        1511         }
1578 }                                                1512 }
1579                                                  1513 
1580 static int aio_read(struct kiocb *req, const  !! 1514 static ssize_t aio_read(struct kiocb *req, struct iocb *iocb, bool vectored,
1581                         bool vectored, bool c !! 1515                 bool compat)
1582 {                                                1516 {
                                                   >> 1517         struct file *file = req->ki_filp;
1583         struct iovec inline_vecs[UIO_FASTIOV]    1518         struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
1584         struct iov_iter iter;                    1519         struct iov_iter iter;
1585         struct file *file;                    !! 1520         ssize_t ret;
1586         int ret;                              << 
1587                                                  1521 
1588         ret = aio_prep_rw(req, iocb, READ);   << 
1589         if (ret)                              << 
1590                 return ret;                   << 
1591         file = req->ki_filp;                  << 
1592         if (unlikely(!(file->f_mode & FMODE_R    1522         if (unlikely(!(file->f_mode & FMODE_READ)))
1593                 return -EBADF;                   1523                 return -EBADF;
1594         if (unlikely(!file->f_op->read_iter))    1524         if (unlikely(!file->f_op->read_iter))
1595                 return -EINVAL;                  1525                 return -EINVAL;
1596                                                  1526 
1597         ret = aio_setup_rw(ITER_DEST, iocb, & !! 1527         ret = aio_setup_rw(READ, iocb, &iovec, vectored, compat, &iter);
1598         if (ret < 0)                          !! 1528         if (ret)
1599                 return ret;                      1529                 return ret;
1600         ret = rw_verify_area(READ, file, &req    1530         ret = rw_verify_area(READ, file, &req->ki_pos, iov_iter_count(&iter));
1601         if (!ret)                                1531         if (!ret)
1602                 aio_rw_done(req, file->f_op-> !! 1532                 ret = aio_ret(req, call_read_iter(file, req, &iter));
1603         kfree(iovec);                            1533         kfree(iovec);
1604         return ret;                              1534         return ret;
1605 }                                                1535 }
1606                                                  1536 
1607 static int aio_write(struct kiocb *req, const !! 1537 static ssize_t aio_write(struct kiocb *req, struct iocb *iocb, bool vectored,
1608                          bool vectored, bool  !! 1538                 bool compat)
1609 {                                                1539 {
                                                   >> 1540         struct file *file = req->ki_filp;
1610         struct iovec inline_vecs[UIO_FASTIOV]    1541         struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
1611         struct iov_iter iter;                    1542         struct iov_iter iter;
1612         struct file *file;                    !! 1543         ssize_t ret;
1613         int ret;                              << 
1614                                               << 
1615         ret = aio_prep_rw(req, iocb, WRITE);  << 
1616         if (ret)                              << 
1617                 return ret;                   << 
1618         file = req->ki_filp;                  << 
1619                                                  1544 
1620         if (unlikely(!(file->f_mode & FMODE_W    1545         if (unlikely(!(file->f_mode & FMODE_WRITE)))
1621                 return -EBADF;                   1546                 return -EBADF;
1622         if (unlikely(!file->f_op->write_iter)    1547         if (unlikely(!file->f_op->write_iter))
1623                 return -EINVAL;                  1548                 return -EINVAL;
1624                                                  1549 
1625         ret = aio_setup_rw(ITER_SOURCE, iocb, !! 1550         ret = aio_setup_rw(WRITE, iocb, &iovec, vectored, compat, &iter);
1626         if (ret < 0)                          !! 1551         if (ret)
1627                 return ret;                      1552                 return ret;
1628         ret = rw_verify_area(WRITE, file, &re    1553         ret = rw_verify_area(WRITE, file, &req->ki_pos, iov_iter_count(&iter));
1629         if (!ret) {                              1554         if (!ret) {
1630                 if (S_ISREG(file_inode(file)- << 
1631                         kiocb_start_write(req << 
1632                 req->ki_flags |= IOCB_WRITE;     1555                 req->ki_flags |= IOCB_WRITE;
1633                 aio_rw_done(req, file->f_op-> !! 1556                 file_start_write(file);
                                                   >> 1557                 ret = aio_ret(req, call_write_iter(file, req, &iter));
                                                   >> 1558                 /*
                                                   >> 1559                  * We release freeze protection in aio_complete().  Fool lockdep
                                                   >> 1560                  * by telling it the lock got released so that it doesn't
                                                   >> 1561                  * complain about held lock when we return to userspace.
                                                   >> 1562                  */
                                                   >> 1563                 if (S_ISREG(file_inode(file)->i_mode))
                                                   >> 1564                         __sb_writers_release(file_inode(file)->i_sb, SB_FREEZE_WRITE);
1634         }                                        1565         }
1635         kfree(iovec);                            1566         kfree(iovec);
1636         return ret;                              1567         return ret;
1637 }                                                1568 }
1638                                                  1569 
1639 static void aio_fsync_work(struct work_struct !! 1570 static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
1640 {                                             !! 1571                          struct iocb *iocb, bool compat)
1641         struct aio_kiocb *iocb = container_of << 
1642         const struct cred *old_cred = overrid << 
1643                                               << 
1644         iocb->ki_res.res = vfs_fsync(iocb->fs << 
1645         revert_creds(old_cred);               << 
1646         put_cred(iocb->fsync.creds);          << 
1647         iocb_put(iocb);                       << 
1648 }                                             << 
1649                                               << 
1650 static int aio_fsync(struct fsync_iocb *req,  << 
1651                      bool datasync)           << 
1652 {                                                1572 {
1653         if (unlikely(iocb->aio_buf || iocb->a !! 1573         struct aio_kiocb *req;
1654                         iocb->aio_rw_flags))  !! 1574         struct file *file;
1655                 return -EINVAL;               !! 1575         ssize_t ret;
1656                                                  1576 
1657         if (unlikely(!req->file->f_op->fsync) !! 1577         /* enforce forwards compatibility on users */
                                                   >> 1578         if (unlikely(iocb->aio_reserved2)) {
                                                   >> 1579                 pr_debug("EINVAL: reserve field set\n");
1658                 return -EINVAL;                  1580                 return -EINVAL;
1659                                               << 
1660         req->creds = prepare_creds();         << 
1661         if (!req->creds)                      << 
1662                 return -ENOMEM;               << 
1663                                               << 
1664         req->datasync = datasync;             << 
1665         INIT_WORK(&req->work, aio_fsync_work) << 
1666         schedule_work(&req->work);            << 
1667         return 0;                             << 
1668 }                                             << 
1669                                               << 
1670 static void aio_poll_put_work(struct work_str << 
1671 {                                             << 
1672         struct poll_iocb *req = container_of( << 
1673         struct aio_kiocb *iocb = container_of << 
1674                                               << 
1675         iocb_put(iocb);                       << 
1676 }                                             << 
1677                                               << 
1678 /*                                            << 
1679  * Safely lock the waitqueue which the reques << 
1680  * case where the ->poll() provider decides t << 
1681  *                                            << 
1682  * Returns true on success, meaning that req- << 
1683  * is on req->head, and an RCU read lock was  << 
1684  * request was already removed from its waitq << 
1685  */                                           << 
1686 static bool poll_iocb_lock_wq(struct poll_ioc << 
1687 {                                             << 
1688         wait_queue_head_t *head;              << 
1689                                               << 
1690         /*                                    << 
1691          * While we hold the waitqueue lock a << 
1692          * wake_up_pollfree() will wait for u << 
1693          * lock in the first place can race w << 
1694          *                                    << 
1695          * We solve this as eventpoll does: b << 
1696          * all users of wake_up_pollfree() wi << 
1697          * we enter rcu_read_lock() and see t << 
1698          * non-NULL, we can then lock it with << 
1699          * under us, then check whether the r << 
1700          *                                    << 
1701          * Keep holding rcu_read_lock() as lo << 
1702          * case the caller deletes the entry  << 
1703          * In that case, only RCU prevents th << 
1704          */                                   << 
1705         rcu_read_lock();                      << 
1706         head = smp_load_acquire(&req->head);  << 
1707         if (head) {                           << 
1708                 spin_lock(&head->lock);       << 
1709                 if (!list_empty(&req->wait.en << 
1710                         return true;          << 
1711                 spin_unlock(&head->lock);     << 
1712         }                                     << 
1713         rcu_read_unlock();                    << 
1714         return false;                         << 
1715 }                                             << 
1716                                               << 
1717 static void poll_iocb_unlock_wq(struct poll_i << 
1718 {                                             << 
1719         spin_unlock(&req->head->lock);        << 
1720         rcu_read_unlock();                    << 
1721 }                                             << 
1722                                               << 
1723 static void aio_poll_complete_work(struct wor << 
1724 {                                             << 
1725         struct poll_iocb *req = container_of( << 
1726         struct aio_kiocb *iocb = container_of << 
1727         struct poll_table_struct pt = { ._key << 
1728         struct kioctx *ctx = iocb->ki_ctx;    << 
1729         __poll_t mask = 0;                    << 
1730                                               << 
1731         if (!READ_ONCE(req->cancelled))       << 
1732                 mask = vfs_poll(req->file, &p << 
1733                                               << 
1734         /*                                    << 
1735          * Note that ->ki_cancel callers also << 
1736          * calling ->ki_cancel.  We need the  << 
1737          * synchronize with them.  In the can << 
1738          * itself is not actually needed, but << 
1739          * avoid further branches in the fast << 
1740          */                                   << 
1741         spin_lock_irq(&ctx->ctx_lock);        << 
1742         if (poll_iocb_lock_wq(req)) {         << 
1743                 if (!mask && !READ_ONCE(req-> << 
1744                         /*                    << 
1745                          * The request isn't  << 
1746                          * Reschedule complet << 
1747                          */                   << 
1748                         if (req->work_need_re << 
1749                                 schedule_work << 
1750                                 req->work_nee << 
1751                         } else {              << 
1752                                 req->work_sch << 
1753                         }                     << 
1754                         poll_iocb_unlock_wq(r << 
1755                         spin_unlock_irq(&ctx- << 
1756                         return;               << 
1757                 }                             << 
1758                 list_del_init(&req->wait.entr << 
1759                 poll_iocb_unlock_wq(req);     << 
1760         } /* else, POLLFREE has freed the wai << 
1761         list_del_init(&iocb->ki_list);        << 
1762         iocb->ki_res.res = mangle_poll(mask); << 
1763         spin_unlock_irq(&ctx->ctx_lock);      << 
1764                                               << 
1765         iocb_put(iocb);                       << 
1766 }                                             << 
1767                                               << 
1768 /* assumes we are called with irqs disabled * << 
1769 static int aio_poll_cancel(struct kiocb *iocb << 
1770 {                                             << 
1771         struct aio_kiocb *aiocb = container_o << 
1772         struct poll_iocb *req = &aiocb->poll; << 
1773                                               << 
1774         if (poll_iocb_lock_wq(req)) {         << 
1775                 WRITE_ONCE(req->cancelled, tr << 
1776                 if (!req->work_scheduled) {   << 
1777                         schedule_work(&aiocb- << 
1778                         req->work_scheduled = << 
1779                 }                             << 
1780                 poll_iocb_unlock_wq(req);     << 
1781         } /* else, the request was force-canc << 
1782                                               << 
1783         return 0;                             << 
1784 }                                             << 
1785                                               << 
1786 static int aio_poll_wake(struct wait_queue_en << 
1787                 void *key)                    << 
1788 {                                             << 
1789         struct poll_iocb *req = container_of( << 
1790         struct aio_kiocb *iocb = container_of << 
1791         __poll_t mask = key_to_poll(key);     << 
1792         unsigned long flags;                  << 
1793                                               << 
1794         /* for instances that support it chec << 
1795         if (mask && !(mask & req->events))    << 
1796                 return 0;                     << 
1797                                               << 
1798         /*                                    << 
1799          * Complete the request inline if pos << 
1800          * conditions be met:                 << 
1801          *   1. An event mask must have been  << 
1802          *      instead, then mask == 0 and w << 
1803          *      the events, so inline complet << 
1804          *   2. The completion work must not  << 
1805          *   3. ctx_lock must not be busy.  W << 
1806          *      already hold the waitqueue lo << 
1807          *      locking order.  Use irqsave/i << 
1808          *      filesystems (e.g. fuse) call  << 
1809          *      yet IRQs have to be disabled  << 
1810          */                                   << 
1811         if (mask && !req->work_scheduled &&   << 
1812             spin_trylock_irqsave(&iocb->ki_ct << 
1813                 struct kioctx *ctx = iocb->ki << 
1814                                               << 
1815                 list_del_init(&req->wait.entr << 
1816                 list_del(&iocb->ki_list);     << 
1817                 iocb->ki_res.res = mangle_pol << 
1818                 if (iocb->ki_eventfd && !even << 
1819                         iocb = NULL;          << 
1820                         INIT_WORK(&req->work, << 
1821                         schedule_work(&req->w << 
1822                 }                             << 
1823                 spin_unlock_irqrestore(&ctx-> << 
1824                 if (iocb)                     << 
1825                         iocb_put(iocb);       << 
1826         } else {                              << 
1827                 /*                            << 
1828                  * Schedule the completion wo << 
1829                  * scheduled, record that ano << 
1830                  *                            << 
1831                  * Don't remove the request f << 
1832                  * not actually be complete y << 
1833                  * is called), and we must no << 
1834                  * exception to this; see bel << 
1835                  */                           << 
1836                 if (req->work_scheduled) {    << 
1837                         req->work_need_resche << 
1838                 } else {                      << 
1839                         schedule_work(&req->w << 
1840                         req->work_scheduled = << 
1841                 }                             << 
1842                                               << 
1843                 /*                            << 
1844                  * If the waitqueue is being  << 
1845                  * the request inline, we hav << 
1846                  * we can.  That means immedi << 
1847                  * waitqueue and preventing a << 
1848                  * waitqueue via the request. << 
1849                  * completion work (done abov << 
1850                  * cancelled, to potentially  << 
1851                  */                           << 
1852                 if (mask & POLLFREE) {        << 
1853                         WRITE_ONCE(req->cance << 
1854                         list_del_init(&req->w << 
1855                                               << 
1856                         /*                    << 
1857                          * Careful: this *mus << 
1858                          * as req->head is NU << 
1859                          * completed and free << 
1860                          * will no longer nee << 
1861                          */                   << 
1862                         smp_store_release(&re << 
1863                 }                             << 
1864         }                                     << 
1865         return 1;                             << 
1866 }                                             << 
1867                                               << 
1868 struct aio_poll_table {                       << 
1869         struct poll_table_struct        pt;   << 
1870         struct aio_kiocb                *iocb << 
1871         bool                            queue << 
1872         int                             error << 
1873 };                                            << 
1874                                               << 
1875 static void                                   << 
1876 aio_poll_queue_proc(struct file *file, struct << 
1877                 struct poll_table_struct *p)  << 
1878 {                                             << 
1879         struct aio_poll_table *pt = container << 
1880                                               << 
1881         /* multiple wait queues per file are  << 
1882         if (unlikely(pt->queued)) {           << 
1883                 pt->error = -EINVAL;          << 
1884                 return;                       << 
1885         }                                        1581         }
1886                                                  1582 
1887         pt->queued = true;                    !! 1583         /* prevent overflows */
1888         pt->error = 0;                        !! 1584         if (unlikely(
1889         pt->iocb->poll.head = head;           !! 1585             (iocb->aio_buf != (unsigned long)iocb->aio_buf) ||
1890         add_wait_queue(head, &pt->iocb->poll. !! 1586             (iocb->aio_nbytes != (size_t)iocb->aio_nbytes) ||
1891 }                                             !! 1587             ((ssize_t)iocb->aio_nbytes < 0)
1892                                               !! 1588            )) {
1893 static int aio_poll(struct aio_kiocb *aiocb,  !! 1589                 pr_debug("EINVAL: overflow check\n");
1894 {                                             << 
1895         struct kioctx *ctx = aiocb->ki_ctx;   << 
1896         struct poll_iocb *req = &aiocb->poll; << 
1897         struct aio_poll_table apt;            << 
1898         bool cancel = false;                  << 
1899         __poll_t mask;                        << 
1900                                               << 
1901         /* reject any unknown events outside  << 
1902         if ((u16)iocb->aio_buf != iocb->aio_b << 
1903                 return -EINVAL;               << 
1904         /* reject fields that are not defined << 
1905         if (iocb->aio_offset || iocb->aio_nby << 
1906                 return -EINVAL;                  1590                 return -EINVAL;
1907                                               << 
1908         INIT_WORK(&req->work, aio_poll_comple << 
1909         req->events = demangle_poll(iocb->aio << 
1910                                               << 
1911         req->head = NULL;                     << 
1912         req->cancelled = false;               << 
1913         req->work_scheduled = false;          << 
1914         req->work_need_resched = false;       << 
1915                                               << 
1916         apt.pt._qproc = aio_poll_queue_proc;  << 
1917         apt.pt._key = req->events;            << 
1918         apt.iocb = aiocb;                     << 
1919         apt.queued = false;                   << 
1920         apt.error = -EINVAL; /* same as no su << 
1921                                               << 
1922         /* initialized the list so that we ca << 
1923         INIT_LIST_HEAD(&req->wait.entry);     << 
1924         init_waitqueue_func_entry(&req->wait, << 
1925                                               << 
1926         mask = vfs_poll(req->file, &apt.pt) & << 
1927         spin_lock_irq(&ctx->ctx_lock);        << 
1928         if (likely(apt.queued)) {             << 
1929                 bool on_queue = poll_iocb_loc << 
1930                                               << 
1931                 if (!on_queue || req->work_sc << 
1932                         /*                    << 
1933                          * aio_poll_wake() al << 
1934                          * completion work, o << 
1935                          */                   << 
1936                         if (apt.error) /* uns << 
1937                                 cancel = true << 
1938                         apt.error = 0;        << 
1939                         mask = 0;             << 
1940                 }                             << 
1941                 if (mask || apt.error) {      << 
1942                         /* Steal to complete  << 
1943                         list_del_init(&req->w << 
1944                 } else if (cancel) {          << 
1945                         /* Cancel if possible << 
1946                         WRITE_ONCE(req->cance << 
1947                 } else if (on_queue) {        << 
1948                         /*                    << 
1949                          * Actually waiting f << 
1950                          * active_reqs so tha << 
1951                          */                   << 
1952                         list_add_tail(&aiocb- << 
1953                         aiocb->ki_cancel = ai << 
1954                 }                             << 
1955                 if (on_queue)                 << 
1956                         poll_iocb_unlock_wq(r << 
1957         }                                        1591         }
1958         if (mask) { /* no async, we'd stolen  << 
1959                 aiocb->ki_res.res = mangle_po << 
1960                 apt.error = 0;                << 
1961         }                                     << 
1962         spin_unlock_irq(&ctx->ctx_lock);      << 
1963         if (mask)                             << 
1964                 iocb_put(aiocb);              << 
1965         return apt.error;                     << 
1966 }                                             << 
1967                                                  1592 
1968 static int __io_submit_one(struct kioctx *ctx !! 1593         req = aio_get_req(ctx);
1969                            struct iocb __user !! 1594         if (unlikely(!req))
1970                            bool compat)       !! 1595                 return -EAGAIN;
1971 {                                             !! 1596 
1972         req->ki_filp = fget(iocb->aio_fildes) !! 1597         req->common.ki_filp = file = fget(iocb->aio_fildes);
1973         if (unlikely(!req->ki_filp))          !! 1598         if (unlikely(!req->common.ki_filp)) {
1974                 return -EBADF;                !! 1599                 ret = -EBADF;
                                                   >> 1600                 goto out_put_req;
                                                   >> 1601         }
                                                   >> 1602         req->common.ki_pos = iocb->aio_offset;
                                                   >> 1603         req->common.ki_complete = aio_complete;
                                                   >> 1604         req->common.ki_flags = iocb_flags(req->common.ki_filp);
                                                   >> 1605         req->common.ki_hint = file_write_hint(file);
1975                                                  1606 
1976         if (iocb->aio_flags & IOCB_FLAG_RESFD    1607         if (iocb->aio_flags & IOCB_FLAG_RESFD) {
1977                 struct eventfd_ctx *eventfd;  << 
1978                 /*                               1608                 /*
1979                  * If the IOCB_FLAG_RESFD fla    1609                  * If the IOCB_FLAG_RESFD flag of aio_flags is set, get an
1980                  * instance of the file* now.    1610                  * instance of the file* now. The file descriptor must be
1981                  * an eventfd() fd, and will     1611                  * an eventfd() fd, and will be signaled for each completed
1982                  * event using the eventfd_si    1612                  * event using the eventfd_signal() function.
1983                  */                              1613                  */
1984                 eventfd = eventfd_ctx_fdget(i !! 1614                 req->ki_eventfd = eventfd_ctx_fdget((int) iocb->aio_resfd);
1985                 if (IS_ERR(eventfd))          !! 1615                 if (IS_ERR(req->ki_eventfd)) {
1986                         return PTR_ERR(eventf !! 1616                         ret = PTR_ERR(req->ki_eventfd);
                                                   >> 1617                         req->ki_eventfd = NULL;
                                                   >> 1618                         goto out_put_req;
                                                   >> 1619                 }
1987                                                  1620 
1988                 req->ki_eventfd = eventfd;    !! 1621                 req->common.ki_flags |= IOCB_EVENTFD;
1989         }                                        1622         }
1990                                                  1623 
1991         if (unlikely(put_user(KIOCB_KEY, &use !! 1624         ret = kiocb_set_rw_flags(&req->common, iocb->aio_rw_flags);
                                                   >> 1625         if (unlikely(ret)) {
                                                   >> 1626                 pr_debug("EINVAL: aio_rw_flags\n");
                                                   >> 1627                 goto out_put_req;
                                                   >> 1628         }
                                                   >> 1629 
                                                   >> 1630         ret = put_user(KIOCB_KEY, &user_iocb->aio_key);
                                                   >> 1631         if (unlikely(ret)) {
1992                 pr_debug("EFAULT: aio_key\n")    1632                 pr_debug("EFAULT: aio_key\n");
1993                 return -EFAULT;               !! 1633                 goto out_put_req;
1994         }                                        1634         }
1995                                                  1635 
1996         req->ki_res.obj = (u64)(unsigned long !! 1636         req->ki_user_iocb = user_iocb;
1997         req->ki_res.data = iocb->aio_data;    !! 1637         req->ki_user_data = iocb->aio_data;
1998         req->ki_res.res = 0;                  << 
1999         req->ki_res.res2 = 0;                 << 
2000                                                  1638 
                                                   >> 1639         get_file(file);
2001         switch (iocb->aio_lio_opcode) {          1640         switch (iocb->aio_lio_opcode) {
2002         case IOCB_CMD_PREAD:                     1641         case IOCB_CMD_PREAD:
2003                 return aio_read(&req->rw, ioc !! 1642                 ret = aio_read(&req->common, iocb, false, compat);
                                                   >> 1643                 break;
2004         case IOCB_CMD_PWRITE:                    1644         case IOCB_CMD_PWRITE:
2005                 return aio_write(&req->rw, io !! 1645                 ret = aio_write(&req->common, iocb, false, compat);
                                                   >> 1646                 break;
2006         case IOCB_CMD_PREADV:                    1647         case IOCB_CMD_PREADV:
2007                 return aio_read(&req->rw, ioc !! 1648                 ret = aio_read(&req->common, iocb, true, compat);
                                                   >> 1649                 break;
2008         case IOCB_CMD_PWRITEV:                   1650         case IOCB_CMD_PWRITEV:
2009                 return aio_write(&req->rw, io !! 1651                 ret = aio_write(&req->common, iocb, true, compat);
2010         case IOCB_CMD_FSYNC:                  !! 1652                 break;
2011                 return aio_fsync(&req->fsync, << 
2012         case IOCB_CMD_FDSYNC:                 << 
2013                 return aio_fsync(&req->fsync, << 
2014         case IOCB_CMD_POLL:                   << 
2015                 return aio_poll(req, iocb);   << 
2016         default:                                 1653         default:
2017                 pr_debug("invalid aio operati    1654                 pr_debug("invalid aio operation %d\n", iocb->aio_lio_opcode);
2018                 return -EINVAL;               !! 1655                 ret = -EINVAL;
                                                   >> 1656                 break;
2019         }                                        1657         }
                                                   >> 1658         fput(file);
                                                   >> 1659 
                                                   >> 1660         if (ret && ret != -EIOCBQUEUED)
                                                   >> 1661                 goto out_put_req;
                                                   >> 1662         return 0;
                                                   >> 1663 out_put_req:
                                                   >> 1664         put_reqs_available(ctx, 1);
                                                   >> 1665         percpu_ref_put(&ctx->reqs);
                                                   >> 1666         kiocb_free(req);
                                                   >> 1667         return ret;
2020 }                                                1668 }
2021                                                  1669 
2022 static int io_submit_one(struct kioctx *ctx,  !! 1670 static long do_io_submit(aio_context_t ctx_id, long nr,
2023                          bool compat)         !! 1671                           struct iocb __user *__user *iocbpp, bool compat)
2024 {                                                1672 {
2025         struct aio_kiocb *req;                !! 1673         struct kioctx *ctx;
2026         struct iocb iocb;                     !! 1674         long ret = 0;
2027         int err;                              !! 1675         int i = 0;
                                                   >> 1676         struct blk_plug plug;
                                                   >> 1677 
                                                   >> 1678         if (unlikely(nr < 0))
                                                   >> 1679                 return -EINVAL;
                                                   >> 1680 
                                                   >> 1681         if (unlikely(nr > LONG_MAX/sizeof(*iocbpp)))
                                                   >> 1682                 nr = LONG_MAX/sizeof(*iocbpp);
2028                                                  1683 
2029         if (unlikely(copy_from_user(&iocb, us !! 1684         if (unlikely(!access_ok(VERIFY_READ, iocbpp, (nr*sizeof(*iocbpp)))))
2030                 return -EFAULT;                  1685                 return -EFAULT;
2031                                                  1686 
2032         /* enforce forwards compatibility on  !! 1687         ctx = lookup_ioctx(ctx_id);
2033         if (unlikely(iocb.aio_reserved2)) {   !! 1688         if (unlikely(!ctx)) {
2034                 pr_debug("EINVAL: reserve fie !! 1689                 pr_debug("EINVAL: invalid context id\n");
2035                 return -EINVAL;                  1690                 return -EINVAL;
2036         }                                        1691         }
2037                                                  1692 
2038         /* prevent overflows */               !! 1693         blk_start_plug(&plug);
2039         if (unlikely(                         << 
2040             (iocb.aio_buf != (unsigned long)i << 
2041             (iocb.aio_nbytes != (size_t)iocb. << 
2042             ((ssize_t)iocb.aio_nbytes < 0)    << 
2043            )) {                               << 
2044                 pr_debug("EINVAL: overflow ch << 
2045                 return -EINVAL;               << 
2046         }                                     << 
2047                                                  1694 
2048         req = aio_get_req(ctx);               !! 1695         /*
2049         if (unlikely(!req))                   !! 1696          * AKPM: should this return a partial result if some of the IOs were
2050                 return -EAGAIN;               !! 1697          * successfully submitted?
                                                   >> 1698          */
                                                   >> 1699         for (i=0; i<nr; i++) {
                                                   >> 1700                 struct iocb __user *user_iocb;
                                                   >> 1701                 struct iocb tmp;
2051                                                  1702 
2052         err = __io_submit_one(ctx, &iocb, use !! 1703                 if (unlikely(__get_user(user_iocb, iocbpp + i))) {
                                                   >> 1704                         ret = -EFAULT;
                                                   >> 1705                         break;
                                                   >> 1706                 }
2053                                                  1707 
2054         /* Done with the synchronous referenc !! 1708                 if (unlikely(copy_from_user(&tmp, user_iocb, sizeof(tmp)))) {
2055         iocb_put(req);                        !! 1709                         ret = -EFAULT;
                                                   >> 1710                         break;
                                                   >> 1711                 }
2056                                                  1712 
2057         /*                                    !! 1713                 ret = io_submit_one(ctx, user_iocb, &tmp, compat);
2058          * If err is 0, we'd either done aio_ !! 1714                 if (ret)
2059          * arranged for that to be done async !! 1715                         break;
2060          * means that we need to destroy req  << 
2061          */                                   << 
2062         if (unlikely(err)) {                  << 
2063                 iocb_destroy(req);            << 
2064                 put_reqs_available(ctx, 1);   << 
2065         }                                        1716         }
2066         return err;                           !! 1717         blk_finish_plug(&plug);
                                                   >> 1718 
                                                   >> 1719         percpu_ref_put(&ctx->users);
                                                   >> 1720         return i ? i : ret;
2067 }                                                1721 }
2068                                                  1722 
2069 /* sys_io_submit:                                1723 /* sys_io_submit:
2070  *      Queue the nr iocbs pointed to by iocb    1724  *      Queue the nr iocbs pointed to by iocbpp for processing.  Returns
2071  *      the number of iocbs queued.  May retu    1725  *      the number of iocbs queued.  May return -EINVAL if the aio_context
2072  *      specified by ctx_id is invalid, if nr    1726  *      specified by ctx_id is invalid, if nr is < 0, if the iocb at
2073  *      *iocbpp[0] is not properly initialize    1727  *      *iocbpp[0] is not properly initialized, if the operation specified
2074  *      is invalid for the file descriptor in    1728  *      is invalid for the file descriptor in the iocb.  May fail with
2075  *      -EFAULT if any of the data structures    1729  *      -EFAULT if any of the data structures point to invalid data.  May
2076  *      fail with -EBADF if the file descript    1730  *      fail with -EBADF if the file descriptor specified in the first
2077  *      iocb is invalid.  May fail with -EAGA    1731  *      iocb is invalid.  May fail with -EAGAIN if insufficient resources
2078  *      are available to queue any iocbs.  Wi    1732  *      are available to queue any iocbs.  Will return 0 if nr is 0.  Will
2079  *      fail with -ENOSYS if not implemented.    1733  *      fail with -ENOSYS if not implemented.
2080  */                                              1734  */
2081 SYSCALL_DEFINE3(io_submit, aio_context_t, ctx    1735 SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr,
2082                 struct iocb __user * __user *    1736                 struct iocb __user * __user *, iocbpp)
2083 {                                                1737 {
2084         struct kioctx *ctx;                   !! 1738         return do_io_submit(ctx_id, nr, iocbpp, 0);
2085         long ret = 0;                         !! 1739 }
2086         int i = 0;                            << 
2087         struct blk_plug plug;                 << 
2088                                                  1740 
2089         if (unlikely(nr < 0))                 !! 1741 #ifdef CONFIG_COMPAT
2090                 return -EINVAL;               !! 1742 static inline long
                                                   >> 1743 copy_iocb(long nr, u32 __user *ptr32, struct iocb __user * __user *ptr64)
                                                   >> 1744 {
                                                   >> 1745         compat_uptr_t uptr;
                                                   >> 1746         int i;
2091                                                  1747 
2092         ctx = lookup_ioctx(ctx_id);           !! 1748         for (i = 0; i < nr; ++i) {
2093         if (unlikely(!ctx)) {                 !! 1749                 if (get_user(uptr, ptr32 + i))
2094                 pr_debug("EINVAL: invalid con !! 1750                         return -EFAULT;
2095                 return -EINVAL;               !! 1751                 if (put_user(compat_ptr(uptr), ptr64 + i))
                                                   >> 1752                         return -EFAULT;
2096         }                                        1753         }
2097                                               !! 1754         return 0;
2098         if (nr > ctx->nr_events)              << 
2099                 nr = ctx->nr_events;          << 
2100                                               << 
2101         if (nr > AIO_PLUG_THRESHOLD)          << 
2102                 blk_start_plug(&plug);        << 
2103         for (i = 0; i < nr; i++) {            << 
2104                 struct iocb __user *user_iocb << 
2105                                               << 
2106                 if (unlikely(get_user(user_io << 
2107                         ret = -EFAULT;        << 
2108                         break;                << 
2109                 }                             << 
2110                                               << 
2111                 ret = io_submit_one(ctx, user << 
2112                 if (ret)                      << 
2113                         break;                << 
2114         }                                     << 
2115         if (nr > AIO_PLUG_THRESHOLD)          << 
2116                 blk_finish_plug(&plug);       << 
2117                                               << 
2118         percpu_ref_put(&ctx->users);          << 
2119         return i ? i : ret;                   << 
2120 }                                                1755 }
2121                                                  1756 
2122 #ifdef CONFIG_COMPAT                          !! 1757 #define MAX_AIO_SUBMITS         (PAGE_SIZE/sizeof(struct iocb *))
                                                   >> 1758 
2123 COMPAT_SYSCALL_DEFINE3(io_submit, compat_aio_    1759 COMPAT_SYSCALL_DEFINE3(io_submit, compat_aio_context_t, ctx_id,
2124                        int, nr, compat_uptr_t !! 1760                        int, nr, u32 __user *, iocb)
2125 {                                                1761 {
2126         struct kioctx *ctx;                   !! 1762         struct iocb __user * __user *iocb64;
2127         long ret = 0;                         !! 1763         long ret;
2128         int i = 0;                            << 
2129         struct blk_plug plug;                 << 
2130                                                  1764 
2131         if (unlikely(nr < 0))                    1765         if (unlikely(nr < 0))
2132                 return -EINVAL;                  1766                 return -EINVAL;
2133                                                  1767 
2134         ctx = lookup_ioctx(ctx_id);           !! 1768         if (nr > MAX_AIO_SUBMITS)
2135         if (unlikely(!ctx)) {                 !! 1769                 nr = MAX_AIO_SUBMITS;
2136                 pr_debug("EINVAL: invalid con << 
2137                 return -EINVAL;               << 
2138         }                                     << 
2139                                                  1770 
2140         if (nr > ctx->nr_events)              !! 1771         iocb64 = compat_alloc_user_space(nr * sizeof(*iocb64));
2141                 nr = ctx->nr_events;          !! 1772         ret = copy_iocb(nr, iocb, iocb64);
                                                   >> 1773         if (!ret)
                                                   >> 1774                 ret = do_io_submit(ctx_id, nr, iocb64, 1);
                                                   >> 1775         return ret;
                                                   >> 1776 }
                                                   >> 1777 #endif
2142                                                  1778 
2143         if (nr > AIO_PLUG_THRESHOLD)          !! 1779 /* lookup_kiocb
2144                 blk_start_plug(&plug);        !! 1780  *      Finds a given iocb for cancellation.
2145         for (i = 0; i < nr; i++) {            !! 1781  */
2146                 compat_uptr_t user_iocb;      !! 1782 static struct aio_kiocb *
                                                   >> 1783 lookup_kiocb(struct kioctx *ctx, struct iocb __user *iocb, u32 key)
                                                   >> 1784 {
                                                   >> 1785         struct aio_kiocb *kiocb;
2147                                                  1786 
2148                 if (unlikely(get_user(user_io !! 1787         assert_spin_locked(&ctx->ctx_lock);
2149                         ret = -EFAULT;        << 
2150                         break;                << 
2151                 }                             << 
2152                                                  1788 
2153                 ret = io_submit_one(ctx, comp !! 1789         if (key != KIOCB_KEY)
2154                 if (ret)                      !! 1790                 return NULL;
2155                         break;                << 
2156         }                                     << 
2157         if (nr > AIO_PLUG_THRESHOLD)          << 
2158                 blk_finish_plug(&plug);       << 
2159                                                  1791 
2160         percpu_ref_put(&ctx->users);          !! 1792         /* TODO: use a hash or array, this sucks. */
2161         return i ? i : ret;                   !! 1793         list_for_each_entry(kiocb, &ctx->active_reqs, ki_list) {
                                                   >> 1794                 if (kiocb->ki_user_iocb == iocb)
                                                   >> 1795                         return kiocb;
                                                   >> 1796         }
                                                   >> 1797         return NULL;
2162 }                                                1798 }
2163 #endif                                        << 
2164                                                  1799 
2165 /* sys_io_cancel:                                1800 /* sys_io_cancel:
2166  *      Attempts to cancel an iocb previously    1801  *      Attempts to cancel an iocb previously passed to io_submit.  If
2167  *      the operation is successfully cancell    1802  *      the operation is successfully cancelled, the resulting event is
2168  *      copied into the memory pointed to by     1803  *      copied into the memory pointed to by result without being placed
2169  *      into the completion queue and 0 is re    1804  *      into the completion queue and 0 is returned.  May fail with
2170  *      -EFAULT if any of the data structures    1805  *      -EFAULT if any of the data structures pointed to are invalid.
2171  *      May fail with -EINVAL if aio_context     1806  *      May fail with -EINVAL if aio_context specified by ctx_id is
2172  *      invalid.  May fail with -EAGAIN if th    1807  *      invalid.  May fail with -EAGAIN if the iocb specified was not
2173  *      cancelled.  Will fail with -ENOSYS if    1808  *      cancelled.  Will fail with -ENOSYS if not implemented.
2174  */                                              1809  */
2175 SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx    1810 SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
2176                 struct io_event __user *, res    1811                 struct io_event __user *, result)
2177 {                                                1812 {
2178         struct kioctx *ctx;                      1813         struct kioctx *ctx;
2179         struct aio_kiocb *kiocb;                 1814         struct aio_kiocb *kiocb;
2180         int ret = -EINVAL;                    << 
2181         u32 key;                                 1815         u32 key;
2182         u64 obj = (u64)(unsigned long)iocb;   !! 1816         int ret;
2183                                                  1817 
2184         if (unlikely(get_user(key, &iocb->aio !! 1818         ret = get_user(key, &iocb->aio_key);
                                                   >> 1819         if (unlikely(ret))
2185                 return -EFAULT;                  1820                 return -EFAULT;
2186         if (unlikely(key != KIOCB_KEY))       << 
2187                 return -EINVAL;               << 
2188                                                  1821 
2189         ctx = lookup_ioctx(ctx_id);              1822         ctx = lookup_ioctx(ctx_id);
2190         if (unlikely(!ctx))                      1823         if (unlikely(!ctx))
2191                 return -EINVAL;                  1824                 return -EINVAL;
2192                                                  1825 
2193         spin_lock_irq(&ctx->ctx_lock);           1826         spin_lock_irq(&ctx->ctx_lock);
2194         /* TODO: use a hash or array, this su !! 1827 
2195         list_for_each_entry(kiocb, &ctx->acti !! 1828         kiocb = lookup_kiocb(ctx, iocb, key);
2196                 if (kiocb->ki_res.obj == obj) !! 1829         if (kiocb)
2197                         ret = kiocb->ki_cance !! 1830                 ret = kiocb_cancel(kiocb);
2198                         list_del_init(&kiocb- !! 1831         else
2199                         break;                !! 1832                 ret = -EINVAL;
2200                 }                             !! 1833 
2201         }                                     << 
2202         spin_unlock_irq(&ctx->ctx_lock);         1834         spin_unlock_irq(&ctx->ctx_lock);
2203                                                  1835 
2204         if (!ret) {                              1836         if (!ret) {
2205                 /*                               1837                 /*
2206                  * The result argument is no     1838                  * The result argument is no longer used - the io_event is
2207                  * always delivered via the r    1839                  * always delivered via the ring buffer. -EINPROGRESS indicates
2208                  * cancellation is progress:     1840                  * cancellation is progress:
2209                  */                              1841                  */
2210                 ret = -EINPROGRESS;              1842                 ret = -EINPROGRESS;
2211         }                                        1843         }
2212                                                  1844 
2213         percpu_ref_put(&ctx->users);             1845         percpu_ref_put(&ctx->users);
2214                                                  1846 
2215         return ret;                              1847         return ret;
2216 }                                                1848 }
2217                                                  1849 
2218 static long do_io_getevents(aio_context_t ctx << 
2219                 long min_nr,                  << 
2220                 long nr,                      << 
2221                 struct io_event __user *event << 
2222                 struct timespec64 *ts)        << 
2223 {                                             << 
2224         ktime_t until = ts ? timespec64_to_kt << 
2225         struct kioctx *ioctx = lookup_ioctx(c << 
2226         long ret = -EINVAL;                   << 
2227                                               << 
2228         if (likely(ioctx)) {                  << 
2229                 if (likely(min_nr <= nr && mi << 
2230                         ret = read_events(ioc << 
2231                 percpu_ref_put(&ioctx->users) << 
2232         }                                     << 
2233                                               << 
2234         return ret;                           << 
2235 }                                             << 
2236                                               << 
2237 /* io_getevents:                                 1850 /* io_getevents:
2238  *      Attempts to read at least min_nr even    1851  *      Attempts to read at least min_nr events and up to nr events from
2239  *      the completion queue for the aio_cont    1852  *      the completion queue for the aio_context specified by ctx_id. If
2240  *      it succeeds, the number of read event    1853  *      it succeeds, the number of read events is returned. May fail with
2241  *      -EINVAL if ctx_id is invalid, if min_    1854  *      -EINVAL if ctx_id is invalid, if min_nr is out of range, if nr is
2242  *      out of range, if timeout is out of ra    1855  *      out of range, if timeout is out of range.  May fail with -EFAULT
2243  *      if any of the memory specified is inv    1856  *      if any of the memory specified is invalid.  May return 0 or
2244  *      < min_nr if the timeout specified by     1857  *      < min_nr if the timeout specified by timeout has elapsed
2245  *      before sufficient events are availabl    1858  *      before sufficient events are available, where timeout == NULL
2246  *      specifies an infinite timeout. Note t    1859  *      specifies an infinite timeout. Note that the timeout pointed to by
2247  *      timeout is relative.  Will fail with     1860  *      timeout is relative.  Will fail with -ENOSYS if not implemented.
2248  */                                              1861  */
2249 #ifdef CONFIG_64BIT                           << 
2250                                               << 
2251 SYSCALL_DEFINE5(io_getevents, aio_context_t,     1862 SYSCALL_DEFINE5(io_getevents, aio_context_t, ctx_id,
2252                 long, min_nr,                    1863                 long, min_nr,
2253                 long, nr,                        1864                 long, nr,
2254                 struct io_event __user *, eve    1865                 struct io_event __user *, events,
2255                 struct __kernel_timespec __us !! 1866                 struct timespec __user *, timeout)
2256 {                                             << 
2257         struct timespec64       ts;           << 
2258         int                     ret;          << 
2259                                               << 
2260         if (timeout && unlikely(get_timespec6 << 
2261                 return -EFAULT;               << 
2262                                               << 
2263         ret = do_io_getevents(ctx_id, min_nr, << 
2264         if (!ret && signal_pending(current))  << 
2265                 ret = -EINTR;                 << 
2266         return ret;                           << 
2267 }                                             << 
2268                                               << 
2269 #endif                                        << 
2270                                               << 
2271 struct __aio_sigset {                         << 
2272         const sigset_t __user   *sigmask;     << 
2273         size_t          sigsetsize;           << 
2274 };                                            << 
2275                                               << 
2276 SYSCALL_DEFINE6(io_pgetevents,                << 
2277                 aio_context_t, ctx_id,        << 
2278                 long, min_nr,                 << 
2279                 long, nr,                     << 
2280                 struct io_event __user *, eve << 
2281                 struct __kernel_timespec __us << 
2282                 const struct __aio_sigset __u << 
2283 {                                             << 
2284         struct __aio_sigset     ksig = { NULL << 
2285         struct timespec64       ts;           << 
2286         bool interrupted;                     << 
2287         int ret;                              << 
2288                                               << 
2289         if (timeout && unlikely(get_timespec6 << 
2290                 return -EFAULT;               << 
2291                                               << 
2292         if (usig && copy_from_user(&ksig, usi << 
2293                 return -EFAULT;               << 
2294                                               << 
2295         ret = set_user_sigmask(ksig.sigmask,  << 
2296         if (ret)                              << 
2297                 return ret;                   << 
2298                                               << 
2299         ret = do_io_getevents(ctx_id, min_nr, << 
2300                                               << 
2301         interrupted = signal_pending(current) << 
2302         restore_saved_sigmask_unless(interrup << 
2303         if (interrupted && !ret)              << 
2304                 ret = -ERESTARTNOHAND;        << 
2305                                               << 
2306         return ret;                           << 
2307 }                                             << 
2308                                               << 
2309 #if defined(CONFIG_COMPAT_32BIT_TIME) && !def << 
2310                                               << 
2311 SYSCALL_DEFINE6(io_pgetevents_time32,         << 
2312                 aio_context_t, ctx_id,        << 
2313                 long, min_nr,                 << 
2314                 long, nr,                     << 
2315                 struct io_event __user *, eve << 
2316                 struct old_timespec32 __user  << 
2317                 const struct __aio_sigset __u << 
2318 {                                             << 
2319         struct __aio_sigset     ksig = { NULL << 
2320         struct timespec64       ts;           << 
2321         bool interrupted;                     << 
2322         int ret;                              << 
2323                                               << 
2324         if (timeout && unlikely(get_old_times << 
2325                 return -EFAULT;               << 
2326                                               << 
2327         if (usig && copy_from_user(&ksig, usi << 
2328                 return -EFAULT;               << 
2329                                               << 
2330                                               << 
2331         ret = set_user_sigmask(ksig.sigmask,  << 
2332         if (ret)                              << 
2333                 return ret;                   << 
2334                                               << 
2335         ret = do_io_getevents(ctx_id, min_nr, << 
2336                                               << 
2337         interrupted = signal_pending(current) << 
2338         restore_saved_sigmask_unless(interrup << 
2339         if (interrupted && !ret)              << 
2340                 ret = -ERESTARTNOHAND;        << 
2341                                               << 
2342         return ret;                           << 
2343 }                                             << 
2344                                               << 
2345 #endif                                        << 
2346                                               << 
2347 #if defined(CONFIG_COMPAT_32BIT_TIME)         << 
2348                                               << 
2349 SYSCALL_DEFINE5(io_getevents_time32, __u32, c << 
2350                 __s32, min_nr,                << 
2351                 __s32, nr,                    << 
2352                 struct io_event __user *, eve << 
2353                 struct old_timespec32 __user  << 
2354 {                                                1867 {
2355         struct timespec64 t;                  !! 1868         struct kioctx *ioctx = lookup_ioctx(ctx_id);
2356         int ret;                              !! 1869         long ret = -EINVAL;
2357                                               << 
2358         if (timeout && get_old_timespec32(&t, << 
2359                 return -EFAULT;               << 
2360                                                  1870 
2361         ret = do_io_getevents(ctx_id, min_nr, !! 1871         if (likely(ioctx)) {
2362         if (!ret && signal_pending(current))  !! 1872                 if (likely(min_nr <= nr && min_nr >= 0))
2363                 ret = -EINTR;                 !! 1873                         ret = read_events(ioctx, min_nr, nr, events, timeout);
                                                   >> 1874                 percpu_ref_put(&ioctx->users);
                                                   >> 1875         }
2364         return ret;                              1876         return ret;
2365 }                                                1877 }
2366                                                  1878 
2367 #endif                                        << 
2368                                               << 
2369 #ifdef CONFIG_COMPAT                             1879 #ifdef CONFIG_COMPAT
2370                                               !! 1880 COMPAT_SYSCALL_DEFINE5(io_getevents, compat_aio_context_t, ctx_id,
2371 struct __compat_aio_sigset {                  !! 1881                        compat_long_t, min_nr,
2372         compat_uptr_t           sigmask;      !! 1882                        compat_long_t, nr,
2373         compat_size_t           sigsetsize;   !! 1883                        struct io_event __user *, events,
2374 };                                            !! 1884                        struct compat_timespec __user *, timeout)
2375                                               !! 1885 {
2376 #if defined(CONFIG_COMPAT_32BIT_TIME)         !! 1886         struct timespec t;
2377                                               !! 1887         struct timespec __user *ut = NULL;
2378 COMPAT_SYSCALL_DEFINE6(io_pgetevents,         !! 1888 
2379                 compat_aio_context_t, ctx_id, !! 1889         if (timeout) {
2380                 compat_long_t, min_nr,        !! 1890                 if (compat_get_timespec(&t, timeout))
2381                 compat_long_t, nr,            !! 1891                         return -EFAULT;
2382                 struct io_event __user *, eve !! 1892 
2383                 struct old_timespec32 __user  !! 1893                 ut = compat_alloc_user_space(sizeof(*ut));
2384                 const struct __compat_aio_sig !! 1894                 if (copy_to_user(ut, &t, sizeof(t)))
2385 {                                             !! 1895                         return -EFAULT;
2386         struct __compat_aio_sigset ksig = { 0 !! 1896         }
2387         struct timespec64 t;                  !! 1897         return sys_io_getevents(ctx_id, min_nr, nr, events, ut);
2388         bool interrupted;                     << 
2389         int ret;                              << 
2390                                               << 
2391         if (timeout && get_old_timespec32(&t, << 
2392                 return -EFAULT;               << 
2393                                               << 
2394         if (usig && copy_from_user(&ksig, usi << 
2395                 return -EFAULT;               << 
2396                                               << 
2397         ret = set_compat_user_sigmask(compat_ << 
2398         if (ret)                              << 
2399                 return ret;                   << 
2400                                               << 
2401         ret = do_io_getevents(ctx_id, min_nr, << 
2402                                               << 
2403         interrupted = signal_pending(current) << 
2404         restore_saved_sigmask_unless(interrup << 
2405         if (interrupted && !ret)              << 
2406                 ret = -ERESTARTNOHAND;        << 
2407                                               << 
2408         return ret;                           << 
2409 }                                             << 
2410                                               << 
2411 #endif                                        << 
2412                                               << 
2413 COMPAT_SYSCALL_DEFINE6(io_pgetevents_time64,  << 
2414                 compat_aio_context_t, ctx_id, << 
2415                 compat_long_t, min_nr,        << 
2416                 compat_long_t, nr,            << 
2417                 struct io_event __user *, eve << 
2418                 struct __kernel_timespec __us << 
2419                 const struct __compat_aio_sig << 
2420 {                                             << 
2421         struct __compat_aio_sigset ksig = { 0 << 
2422         struct timespec64 t;                  << 
2423         bool interrupted;                     << 
2424         int ret;                              << 
2425                                               << 
2426         if (timeout && get_timespec64(&t, tim << 
2427                 return -EFAULT;               << 
2428                                               << 
2429         if (usig && copy_from_user(&ksig, usi << 
2430                 return -EFAULT;               << 
2431                                               << 
2432         ret = set_compat_user_sigmask(compat_ << 
2433         if (ret)                              << 
2434                 return ret;                   << 
2435                                               << 
2436         ret = do_io_getevents(ctx_id, min_nr, << 
2437                                               << 
2438         interrupted = signal_pending(current) << 
2439         restore_saved_sigmask_unless(interrup << 
2440         if (interrupted && !ret)              << 
2441                 ret = -ERESTARTNOHAND;        << 
2442                                               << 
2443         return ret;                           << 
2444 }                                                1898 }
2445 #endif                                           1899 #endif
2446                                                  1900 

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