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
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.