1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Super block/filesystem wide operations
4 *
5 * Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk> and
6 * Michael Callahan <callahan@maths.ox.ac.uk>
7 *
8 * Rewritten for Linux 2.1. Peter Braam <braam@cs.cmu.edu>
9 * Copyright (C) Carnegie Mellon University
10 */
11
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/mm.h>
15 #include <linux/string.h>
16 #include <linux/stat.h>
17 #include <linux/errno.h>
18 #include <linux/unistd.h>
19 #include <linux/mutex.h>
20 #include <linux/spinlock.h>
21 #include <linux/file.h>
22 #include <linux/vfs.h>
23 #include <linux/slab.h>
24 #include <linux/pid_namespace.h>
25 #include <linux/uaccess.h>
26 #include <linux/fs.h>
27 #include <linux/fs_context.h>
28 #include <linux/fs_parser.h>
29 #include <linux/vmalloc.h>
30
31 #include <linux/coda.h>
32 #include "coda_psdev.h"
33 #include "coda_linux.h"
34 #include "coda_cache.h"
35
36 #include "coda_int.h"
37
38 /* VFS super_block ops */
39 static void coda_evict_inode(struct inode *);
40 static void coda_put_super(struct super_block *);
41 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
42
43 static struct kmem_cache * coda_inode_cachep;
44
45 static struct inode *coda_alloc_inode(struct super_block *sb)
46 {
47 struct coda_inode_info *ei;
48 ei = alloc_inode_sb(sb, coda_inode_cachep, GFP_KERNEL);
49 if (!ei)
50 return NULL;
51 memset(&ei->c_fid, 0, sizeof(struct CodaFid));
52 ei->c_flags = 0;
53 ei->c_uid = GLOBAL_ROOT_UID;
54 ei->c_cached_perm = 0;
55 spin_lock_init(&ei->c_lock);
56 return &ei->vfs_inode;
57 }
58
59 static void coda_free_inode(struct inode *inode)
60 {
61 kmem_cache_free(coda_inode_cachep, ITOC(inode));
62 }
63
64 static void init_once(void *foo)
65 {
66 struct coda_inode_info *ei = (struct coda_inode_info *) foo;
67
68 inode_init_once(&ei->vfs_inode);
69 }
70
71 int __init coda_init_inodecache(void)
72 {
73 coda_inode_cachep = kmem_cache_create("coda_inode_cache",
74 sizeof(struct coda_inode_info), 0,
75 SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,
76 init_once);
77 if (coda_inode_cachep == NULL)
78 return -ENOMEM;
79 return 0;
80 }
81
82 void coda_destroy_inodecache(void)
83 {
84 /*
85 * Make sure all delayed rcu free inodes are flushed before we
86 * destroy cache.
87 */
88 rcu_barrier();
89 kmem_cache_destroy(coda_inode_cachep);
90 }
91
92 static int coda_reconfigure(struct fs_context *fc)
93 {
94 sync_filesystem(fc->root->d_sb);
95 fc->sb_flags |= SB_NOATIME;
96 return 0;
97 }
98
99 /* exported operations */
100 static const struct super_operations coda_super_operations =
101 {
102 .alloc_inode = coda_alloc_inode,
103 .free_inode = coda_free_inode,
104 .evict_inode = coda_evict_inode,
105 .put_super = coda_put_super,
106 .statfs = coda_statfs,
107 };
108
109 struct coda_fs_context {
110 int idx;
111 };
112
113 enum {
114 Opt_fd,
115 };
116
117 static const struct fs_parameter_spec coda_param_specs[] = {
118 fsparam_fd ("fd", Opt_fd),
119 {}
120 };
121
122 static int coda_parse_fd(struct fs_context *fc, int fd)
123 {
124 struct coda_fs_context *ctx = fc->fs_private;
125 struct fd f;
126 struct inode *inode;
127 int idx;
128
129 f = fdget(fd);
130 if (!f.file)
131 return -EBADF;
132 inode = file_inode(f.file);
133 if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
134 fdput(f);
135 return invalf(fc, "code: Not coda psdev");
136 }
137
138 idx = iminor(inode);
139 fdput(f);
140
141 if (idx < 0 || idx >= MAX_CODADEVS)
142 return invalf(fc, "coda: Bad minor number");
143 ctx->idx = idx;
144 return 0;
145 }
146
147 static int coda_parse_param(struct fs_context *fc, struct fs_parameter *param)
148 {
149 struct fs_parse_result result;
150 int opt;
151
152 opt = fs_parse(fc, coda_param_specs, param, &result);
153 if (opt < 0)
154 return opt;
155
156 switch (opt) {
157 case Opt_fd:
158 return coda_parse_fd(fc, result.uint_32);
159 }
160
161 return 0;
162 }
163
164 /*
165 * Parse coda's binary mount data form. We ignore any errors and go with index
166 * 0 if we get one for backward compatibility.
167 */
168 static int coda_parse_monolithic(struct fs_context *fc, void *_data)
169 {
170 struct coda_mount_data *data = _data;
171
172 if (!data)
173 return invalf(fc, "coda: Bad mount data");
174
175 if (data->version != CODA_MOUNT_VERSION)
176 return invalf(fc, "coda: Bad mount version");
177
178 coda_parse_fd(fc, data->fd);
179 return 0;
180 }
181
182 static int coda_fill_super(struct super_block *sb, struct fs_context *fc)
183 {
184 struct coda_fs_context *ctx = fc->fs_private;
185 struct inode *root = NULL;
186 struct venus_comm *vc;
187 struct CodaFid fid;
188 int error;
189
190 infof(fc, "coda: device index: %i\n", ctx->idx);
191
192 vc = &coda_comms[ctx->idx];
193 mutex_lock(&vc->vc_mutex);
194
195 if (!vc->vc_inuse) {
196 errorf(fc, "coda: No pseudo device");
197 error = -EINVAL;
198 goto unlock_out;
199 }
200
201 if (vc->vc_sb) {
202 errorf(fc, "coda: Device already mounted");
203 error = -EBUSY;
204 goto unlock_out;
205 }
206
207 vc->vc_sb = sb;
208 mutex_unlock(&vc->vc_mutex);
209
210 sb->s_fs_info = vc;
211 sb->s_flags |= SB_NOATIME;
212 sb->s_blocksize = 4096; /* XXXXX what do we put here?? */
213 sb->s_blocksize_bits = 12;
214 sb->s_magic = CODA_SUPER_MAGIC;
215 sb->s_op = &coda_super_operations;
216 sb->s_d_op = &coda_dentry_operations;
217 sb->s_time_gran = 1;
218 sb->s_time_min = S64_MIN;
219 sb->s_time_max = S64_MAX;
220
221 error = super_setup_bdi(sb);
222 if (error)
223 goto error;
224
225 /* get root fid from Venus: this needs the root inode */
226 error = venus_rootfid(sb, &fid);
227 if ( error ) {
228 pr_warn("%s: coda_get_rootfid failed with %d\n",
229 __func__, error);
230 goto error;
231 }
232 pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid));
233
234 /* make root inode */
235 root = coda_cnode_make(&fid, sb);
236 if (IS_ERR(root)) {
237 error = PTR_ERR(root);
238 pr_warn("Failure of coda_cnode_make for root: error %d\n",
239 error);
240 goto error;
241 }
242
243 pr_info("%s: rootinode is %ld dev %s\n",
244 __func__, root->i_ino, root->i_sb->s_id);
245 sb->s_root = d_make_root(root);
246 if (!sb->s_root) {
247 error = -EINVAL;
248 goto error;
249 }
250 return 0;
251
252 error:
253 mutex_lock(&vc->vc_mutex);
254 vc->vc_sb = NULL;
255 sb->s_fs_info = NULL;
256 unlock_out:
257 mutex_unlock(&vc->vc_mutex);
258 return error;
259 }
260
261 static void coda_put_super(struct super_block *sb)
262 {
263 struct venus_comm *vcp = coda_vcp(sb);
264 mutex_lock(&vcp->vc_mutex);
265 vcp->vc_sb = NULL;
266 sb->s_fs_info = NULL;
267 mutex_unlock(&vcp->vc_mutex);
268 mutex_destroy(&vcp->vc_mutex);
269
270 pr_info("Bye bye.\n");
271 }
272
273 static void coda_evict_inode(struct inode *inode)
274 {
275 truncate_inode_pages_final(&inode->i_data);
276 clear_inode(inode);
277 coda_cache_clear_inode(inode);
278 }
279
280 int coda_getattr(struct mnt_idmap *idmap, const struct path *path,
281 struct kstat *stat, u32 request_mask, unsigned int flags)
282 {
283 int err = coda_revalidate_inode(d_inode(path->dentry));
284 if (!err)
285 generic_fillattr(&nop_mnt_idmap, request_mask,
286 d_inode(path->dentry), stat);
287 return err;
288 }
289
290 int coda_setattr(struct mnt_idmap *idmap, struct dentry *de,
291 struct iattr *iattr)
292 {
293 struct inode *inode = d_inode(de);
294 struct coda_vattr vattr;
295 int error;
296
297 memset(&vattr, 0, sizeof(vattr));
298
299 inode_set_ctime_current(inode);
300 coda_iattr_to_vattr(iattr, &vattr);
301 vattr.va_type = C_VNON; /* cannot set type */
302
303 /* Venus is responsible for truncating the container-file!!! */
304 error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
305
306 if (!error) {
307 coda_vattr_to_iattr(inode, &vattr);
308 coda_cache_clear_inode(inode);
309 }
310 return error;
311 }
312
313 const struct inode_operations coda_file_inode_operations = {
314 .permission = coda_permission,
315 .getattr = coda_getattr,
316 .setattr = coda_setattr,
317 };
318
319 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
320 {
321 int error;
322
323 error = venus_statfs(dentry, buf);
324
325 if (error) {
326 /* fake something like AFS does */
327 buf->f_blocks = 9000000;
328 buf->f_bfree = 9000000;
329 buf->f_bavail = 9000000;
330 buf->f_files = 9000000;
331 buf->f_ffree = 9000000;
332 }
333
334 /* and fill in the rest */
335 buf->f_type = CODA_SUPER_MAGIC;
336 buf->f_bsize = 4096;
337 buf->f_namelen = CODA_MAXNAMLEN;
338
339 return 0;
340 }
341
342 static int coda_get_tree(struct fs_context *fc)
343 {
344 if (task_active_pid_ns(current) != &init_pid_ns)
345 return -EINVAL;
346
347 return get_tree_nodev(fc, coda_fill_super);
348 }
349
350 static void coda_free_fc(struct fs_context *fc)
351 {
352 kfree(fc->fs_private);
353 }
354
355 static const struct fs_context_operations coda_context_ops = {
356 .free = coda_free_fc,
357 .parse_param = coda_parse_param,
358 .parse_monolithic = coda_parse_monolithic,
359 .get_tree = coda_get_tree,
360 .reconfigure = coda_reconfigure,
361 };
362
363 static int coda_init_fs_context(struct fs_context *fc)
364 {
365 struct coda_fs_context *ctx;
366
367 ctx = kzalloc(sizeof(struct coda_fs_context), GFP_KERNEL);
368 if (!ctx)
369 return -ENOMEM;
370
371 fc->fs_private = ctx;
372 fc->ops = &coda_context_ops;
373 return 0;
374 }
375
376 struct file_system_type coda_fs_type = {
377 .owner = THIS_MODULE,
378 .name = "coda",
379 .init_fs_context = coda_init_fs_context,
380 .parameters = coda_param_specs,
381 .kill_sb = kill_anon_super,
382 .fs_flags = FS_BINARY_MOUNTDATA,
383 };
384 MODULE_ALIAS_FS("coda");
385
386
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