Commit | Line | Data |
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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/fs/locks.c | |
4 | * | |
e9728cc7 BF |
5 | * We implement four types of file locks: BSD locks, posix locks, open |
6 | * file description locks, and leases. For details about BSD locks, | |
7 | * see the flock(2) man page; for details about the other three, see | |
8 | * fcntl(2). | |
1da177e4 | 9 | * |
fd7732e0 N |
10 | * |
11 | * Locking conflicts and dependencies: | |
12 | * If multiple threads attempt to lock the same byte (or flock the same file) | |
13 | * only one can be granted the lock, and other must wait their turn. | |
14 | * The first lock has been "applied" or "granted", the others are "waiting" | |
15 | * and are "blocked" by the "applied" lock.. | |
16 | * | |
17 | * Waiting and applied locks are all kept in trees whose properties are: | |
18 | * | |
19 | * - the root of a tree may be an applied or waiting lock. | |
20 | * - every other node in the tree is a waiting lock that | |
21 | * conflicts with every ancestor of that node. | |
22 | * | |
23 | * Every such tree begins life as a waiting singleton which obviously | |
24 | * satisfies the above properties. | |
25 | * | |
26 | * The only ways we modify trees preserve these properties: | |
27 | * | |
28 | * 1. We may add a new leaf node, but only after first verifying that it | |
29 | * conflicts with all of its ancestors. | |
30 | * 2. We may remove the root of a tree, creating a new singleton | |
31 | * tree from the root and N new trees rooted in the immediate | |
32 | * children. | |
33 | * 3. If the root of a tree is not currently an applied lock, we may | |
34 | * apply it (if possible). | |
35 | * 4. We may upgrade the root of the tree (either extend its range, | |
36 | * or upgrade its entire range from read to write). | |
37 | * | |
38 | * When an applied lock is modified in a way that reduces or downgrades any | |
39 | * part of its range, we remove all its children (2 above). This particularly | |
40 | * happens when a lock is unlocked. | |
41 | * | |
42 | * For each of those child trees we "wake up" the thread which is | |
43 | * waiting for the lock so it can continue handling as follows: if the | |
44 | * root of the tree applies, we do so (3). If it doesn't, it must | |
45 | * conflict with some applied lock. We remove (wake up) all of its children | |
46 | * (2), and add it is a new leaf to the tree rooted in the applied | |
47 | * lock (1). We then repeat the process recursively with those | |
48 | * children. | |
49 | * | |
1da177e4 LT |
50 | */ |
51 | ||
52 | #include <linux/capability.h> | |
53 | #include <linux/file.h> | |
9f3acc31 | 54 | #include <linux/fdtable.h> |
1da177e4 LT |
55 | #include <linux/fs.h> |
56 | #include <linux/init.h> | |
1da177e4 LT |
57 | #include <linux/security.h> |
58 | #include <linux/slab.h> | |
1da177e4 LT |
59 | #include <linux/syscalls.h> |
60 | #include <linux/time.h> | |
4fb3a538 | 61 | #include <linux/rcupdate.h> |
ab1f1611 | 62 | #include <linux/pid_namespace.h> |
48f74186 | 63 | #include <linux/hashtable.h> |
7012b02a | 64 | #include <linux/percpu.h> |
1da177e4 | 65 | |
62af4f1f JL |
66 | #define CREATE_TRACE_POINTS |
67 | #include <trace/events/filelock.h> | |
68 | ||
7c0f6ba6 | 69 | #include <linux/uaccess.h> |
1da177e4 LT |
70 | |
71 | #define IS_POSIX(fl) (fl->fl_flags & FL_POSIX) | |
72 | #define IS_FLOCK(fl) (fl->fl_flags & FL_FLOCK) | |
11afe9f7 | 73 | #define IS_LEASE(fl) (fl->fl_flags & (FL_LEASE|FL_DELEG|FL_LAYOUT)) |
cff2fce5 | 74 | #define IS_OFDLCK(fl) (fl->fl_flags & FL_OFDLCK) |
9d5b86ac | 75 | #define IS_REMOTELCK(fl) (fl->fl_pid <= 0) |
1da177e4 | 76 | |
ab83fa4b BF |
77 | static bool lease_breaking(struct file_lock *fl) |
78 | { | |
778fc546 BF |
79 | return fl->fl_flags & (FL_UNLOCK_PENDING | FL_DOWNGRADE_PENDING); |
80 | } | |
81 | ||
82 | static int target_leasetype(struct file_lock *fl) | |
83 | { | |
84 | if (fl->fl_flags & FL_UNLOCK_PENDING) | |
85 | return F_UNLCK; | |
86 | if (fl->fl_flags & FL_DOWNGRADE_PENDING) | |
87 | return F_RDLCK; | |
88 | return fl->fl_type; | |
ab83fa4b BF |
89 | } |
90 | ||
1da177e4 LT |
91 | int leases_enable = 1; |
92 | int lease_break_time = 45; | |
93 | ||
1c8c601a | 94 | /* |
7012b02a | 95 | * The global file_lock_list is only used for displaying /proc/locks, so we |
7c3f654d PZ |
96 | * keep a list on each CPU, with each list protected by its own spinlock. |
97 | * Global serialization is done using file_rwsem. | |
98 | * | |
99 | * Note that alterations to the list also require that the relevant flc_lock is | |
100 | * held. | |
1c8c601a | 101 | */ |
7c3f654d PZ |
102 | struct file_lock_list_struct { |
103 | spinlock_t lock; | |
104 | struct hlist_head hlist; | |
105 | }; | |
106 | static DEFINE_PER_CPU(struct file_lock_list_struct, file_lock_list); | |
aba37660 | 107 | DEFINE_STATIC_PERCPU_RWSEM(file_rwsem); |
88974691 | 108 | |
eb82dd39 | 109 | |
1c8c601a | 110 | /* |
48f74186 | 111 | * The blocked_hash is used to find POSIX lock loops for deadlock detection. |
7b2296af | 112 | * It is protected by blocked_lock_lock. |
48f74186 JL |
113 | * |
114 | * We hash locks by lockowner in order to optimize searching for the lock a | |
115 | * particular lockowner is waiting on. | |
116 | * | |
117 | * FIXME: make this value scale via some heuristic? We generally will want more | |
118 | * buckets when we have more lockowners holding locks, but that's a little | |
119 | * difficult to determine without knowing what the workload will look like. | |
1c8c601a | 120 | */ |
48f74186 JL |
121 | #define BLOCKED_HASH_BITS 7 |
122 | static DEFINE_HASHTABLE(blocked_hash, BLOCKED_HASH_BITS); | |
88974691 | 123 | |
1c8c601a | 124 | /* |
7b2296af JL |
125 | * This lock protects the blocked_hash. Generally, if you're accessing it, you |
126 | * want to be holding this lock. | |
1c8c601a | 127 | * |
ada5c1da N |
128 | * In addition, it also protects the fl->fl_blocked_requests list, and the |
129 | * fl->fl_blocker pointer for file_lock structures that are acting as lock | |
130 | * requests (in contrast to those that are acting as records of acquired locks). | |
1c8c601a JL |
131 | * |
132 | * Note that when we acquire this lock in order to change the above fields, | |
6109c850 | 133 | * we often hold the flc_lock as well. In certain cases, when reading the fields |
1c8c601a | 134 | * protected by this lock, we can skip acquiring it iff we already hold the |
6109c850 | 135 | * flc_lock. |
1c8c601a | 136 | */ |
7b2296af | 137 | static DEFINE_SPINLOCK(blocked_lock_lock); |
1da177e4 | 138 | |
4a075e39 | 139 | static struct kmem_cache *flctx_cache __read_mostly; |
e18b890b | 140 | static struct kmem_cache *filelock_cache __read_mostly; |
1da177e4 | 141 | |
4a075e39 | 142 | static struct file_lock_context * |
5c1c669a | 143 | locks_get_lock_context(struct inode *inode, int type) |
4a075e39 | 144 | { |
128a3785 | 145 | struct file_lock_context *ctx; |
4a075e39 | 146 | |
128a3785 DV |
147 | /* paired with cmpxchg() below */ |
148 | ctx = smp_load_acquire(&inode->i_flctx); | |
149 | if (likely(ctx) || type == F_UNLCK) | |
4a075e39 JL |
150 | goto out; |
151 | ||
128a3785 DV |
152 | ctx = kmem_cache_alloc(flctx_cache, GFP_KERNEL); |
153 | if (!ctx) | |
4a075e39 JL |
154 | goto out; |
155 | ||
128a3785 DV |
156 | spin_lock_init(&ctx->flc_lock); |
157 | INIT_LIST_HEAD(&ctx->flc_flock); | |
158 | INIT_LIST_HEAD(&ctx->flc_posix); | |
159 | INIT_LIST_HEAD(&ctx->flc_lease); | |
4a075e39 JL |
160 | |
161 | /* | |
162 | * Assign the pointer if it's not already assigned. If it is, then | |
163 | * free the context we just allocated. | |
164 | */ | |
128a3785 DV |
165 | if (cmpxchg(&inode->i_flctx, NULL, ctx)) { |
166 | kmem_cache_free(flctx_cache, ctx); | |
167 | ctx = smp_load_acquire(&inode->i_flctx); | |
168 | } | |
4a075e39 | 169 | out: |
1890910f | 170 | trace_locks_get_lock_context(inode, type, ctx); |
128a3785 | 171 | return ctx; |
4a075e39 JL |
172 | } |
173 | ||
e24dadab JL |
174 | static void |
175 | locks_dump_ctx_list(struct list_head *list, char *list_type) | |
176 | { | |
177 | struct file_lock *fl; | |
178 | ||
179 | list_for_each_entry(fl, list, fl_list) { | |
180 | pr_warn("%s: fl_owner=%p fl_flags=0x%x fl_type=0x%x fl_pid=%u\n", list_type, fl->fl_owner, fl->fl_flags, fl->fl_type, fl->fl_pid); | |
181 | } | |
182 | } | |
183 | ||
184 | static void | |
185 | locks_check_ctx_lists(struct inode *inode) | |
186 | { | |
187 | struct file_lock_context *ctx = inode->i_flctx; | |
188 | ||
189 | if (unlikely(!list_empty(&ctx->flc_flock) || | |
190 | !list_empty(&ctx->flc_posix) || | |
191 | !list_empty(&ctx->flc_lease))) { | |
192 | pr_warn("Leaked locks on dev=0x%x:0x%x ino=0x%lx:\n", | |
193 | MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev), | |
194 | inode->i_ino); | |
195 | locks_dump_ctx_list(&ctx->flc_flock, "FLOCK"); | |
196 | locks_dump_ctx_list(&ctx->flc_posix, "POSIX"); | |
197 | locks_dump_ctx_list(&ctx->flc_lease, "LEASE"); | |
198 | } | |
199 | } | |
200 | ||
3953704f BC |
201 | static void |
202 | locks_check_ctx_file_list(struct file *filp, struct list_head *list, | |
203 | char *list_type) | |
204 | { | |
205 | struct file_lock *fl; | |
206 | struct inode *inode = locks_inode(filp); | |
207 | ||
208 | list_for_each_entry(fl, list, fl_list) | |
209 | if (fl->fl_file == filp) | |
210 | pr_warn("Leaked %s lock on dev=0x%x:0x%x ino=0x%lx " | |
211 | " fl_owner=%p fl_flags=0x%x fl_type=0x%x fl_pid=%u\n", | |
212 | list_type, MAJOR(inode->i_sb->s_dev), | |
213 | MINOR(inode->i_sb->s_dev), inode->i_ino, | |
214 | fl->fl_owner, fl->fl_flags, fl->fl_type, fl->fl_pid); | |
215 | } | |
216 | ||
4a075e39 | 217 | void |
f27a0fe0 | 218 | locks_free_lock_context(struct inode *inode) |
4a075e39 | 219 | { |
f27a0fe0 JL |
220 | struct file_lock_context *ctx = inode->i_flctx; |
221 | ||
e24dadab JL |
222 | if (unlikely(ctx)) { |
223 | locks_check_ctx_lists(inode); | |
4a075e39 JL |
224 | kmem_cache_free(flctx_cache, ctx); |
225 | } | |
226 | } | |
227 | ||
ee19cc40 | 228 | static void locks_init_lock_heads(struct file_lock *fl) |
a51cb91d | 229 | { |
139ca04e | 230 | INIT_HLIST_NODE(&fl->fl_link); |
6dee60f6 | 231 | INIT_LIST_HEAD(&fl->fl_list); |
ada5c1da N |
232 | INIT_LIST_HEAD(&fl->fl_blocked_requests); |
233 | INIT_LIST_HEAD(&fl->fl_blocked_member); | |
ee19cc40 | 234 | init_waitqueue_head(&fl->fl_wait); |
a51cb91d MS |
235 | } |
236 | ||
1da177e4 | 237 | /* Allocate an empty lock structure. */ |
c5b1f0d9 | 238 | struct file_lock *locks_alloc_lock(void) |
1da177e4 | 239 | { |
ee19cc40 | 240 | struct file_lock *fl = kmem_cache_zalloc(filelock_cache, GFP_KERNEL); |
a51cb91d MS |
241 | |
242 | if (fl) | |
ee19cc40 | 243 | locks_init_lock_heads(fl); |
a51cb91d MS |
244 | |
245 | return fl; | |
1da177e4 | 246 | } |
c5b1f0d9 | 247 | EXPORT_SYMBOL_GPL(locks_alloc_lock); |
1da177e4 | 248 | |
a9e61e25 | 249 | void locks_release_private(struct file_lock *fl) |
47831f35 | 250 | { |
5926459e N |
251 | BUG_ON(waitqueue_active(&fl->fl_wait)); |
252 | BUG_ON(!list_empty(&fl->fl_list)); | |
253 | BUG_ON(!list_empty(&fl->fl_blocked_requests)); | |
254 | BUG_ON(!list_empty(&fl->fl_blocked_member)); | |
255 | BUG_ON(!hlist_unhashed(&fl->fl_link)); | |
256 | ||
47831f35 TM |
257 | if (fl->fl_ops) { |
258 | if (fl->fl_ops->fl_release_private) | |
259 | fl->fl_ops->fl_release_private(fl); | |
260 | fl->fl_ops = NULL; | |
261 | } | |
47831f35 | 262 | |
5c97d7b1 | 263 | if (fl->fl_lmops) { |
cae80b30 JL |
264 | if (fl->fl_lmops->lm_put_owner) { |
265 | fl->fl_lmops->lm_put_owner(fl->fl_owner); | |
266 | fl->fl_owner = NULL; | |
267 | } | |
5c97d7b1 KM |
268 | fl->fl_lmops = NULL; |
269 | } | |
47831f35 | 270 | } |
a9e61e25 | 271 | EXPORT_SYMBOL_GPL(locks_release_private); |
47831f35 | 272 | |
1da177e4 | 273 | /* Free a lock which is not in use. */ |
05fa3135 | 274 | void locks_free_lock(struct file_lock *fl) |
1da177e4 | 275 | { |
47831f35 | 276 | locks_release_private(fl); |
1da177e4 LT |
277 | kmem_cache_free(filelock_cache, fl); |
278 | } | |
05fa3135 | 279 | EXPORT_SYMBOL(locks_free_lock); |
1da177e4 | 280 | |
ed9814d8 JL |
281 | static void |
282 | locks_dispose_list(struct list_head *dispose) | |
283 | { | |
284 | struct file_lock *fl; | |
285 | ||
286 | while (!list_empty(dispose)) { | |
6dee60f6 JL |
287 | fl = list_first_entry(dispose, struct file_lock, fl_list); |
288 | list_del_init(&fl->fl_list); | |
ed9814d8 JL |
289 | locks_free_lock(fl); |
290 | } | |
291 | } | |
292 | ||
1da177e4 LT |
293 | void locks_init_lock(struct file_lock *fl) |
294 | { | |
ee19cc40 MS |
295 | memset(fl, 0, sizeof(struct file_lock)); |
296 | locks_init_lock_heads(fl); | |
1da177e4 | 297 | } |
1da177e4 LT |
298 | EXPORT_SYMBOL(locks_init_lock); |
299 | ||
1da177e4 LT |
300 | /* |
301 | * Initialize a new lock from an existing file_lock structure. | |
302 | */ | |
3fe0fff1 | 303 | void locks_copy_conflock(struct file_lock *new, struct file_lock *fl) |
1da177e4 LT |
304 | { |
305 | new->fl_owner = fl->fl_owner; | |
306 | new->fl_pid = fl->fl_pid; | |
0996905f | 307 | new->fl_file = NULL; |
1da177e4 LT |
308 | new->fl_flags = fl->fl_flags; |
309 | new->fl_type = fl->fl_type; | |
310 | new->fl_start = fl->fl_start; | |
311 | new->fl_end = fl->fl_end; | |
f328296e | 312 | new->fl_lmops = fl->fl_lmops; |
0996905f | 313 | new->fl_ops = NULL; |
f328296e KM |
314 | |
315 | if (fl->fl_lmops) { | |
316 | if (fl->fl_lmops->lm_get_owner) | |
cae80b30 | 317 | fl->fl_lmops->lm_get_owner(fl->fl_owner); |
f328296e | 318 | } |
0996905f | 319 | } |
3fe0fff1 | 320 | EXPORT_SYMBOL(locks_copy_conflock); |
0996905f TM |
321 | |
322 | void locks_copy_lock(struct file_lock *new, struct file_lock *fl) | |
323 | { | |
566709bd JL |
324 | /* "new" must be a freshly-initialized lock */ |
325 | WARN_ON_ONCE(new->fl_ops); | |
0996905f | 326 | |
3fe0fff1 | 327 | locks_copy_conflock(new, fl); |
f328296e | 328 | |
0996905f | 329 | new->fl_file = fl->fl_file; |
1da177e4 | 330 | new->fl_ops = fl->fl_ops; |
47831f35 | 331 | |
f328296e KM |
332 | if (fl->fl_ops) { |
333 | if (fl->fl_ops->fl_copy_lock) | |
334 | fl->fl_ops->fl_copy_lock(new, fl); | |
335 | } | |
1da177e4 | 336 | } |
1da177e4 LT |
337 | EXPORT_SYMBOL(locks_copy_lock); |
338 | ||
5946c431 N |
339 | static void locks_move_blocks(struct file_lock *new, struct file_lock *fl) |
340 | { | |
341 | struct file_lock *f; | |
342 | ||
343 | /* | |
344 | * As ctx->flc_lock is held, new requests cannot be added to | |
345 | * ->fl_blocked_requests, so we don't need a lock to check if it | |
346 | * is empty. | |
347 | */ | |
348 | if (list_empty(&fl->fl_blocked_requests)) | |
349 | return; | |
350 | spin_lock(&blocked_lock_lock); | |
351 | list_splice_init(&fl->fl_blocked_requests, &new->fl_blocked_requests); | |
bf77ae4c | 352 | list_for_each_entry(f, &new->fl_blocked_requests, fl_blocked_member) |
5946c431 N |
353 | f->fl_blocker = new; |
354 | spin_unlock(&blocked_lock_lock); | |
355 | } | |
356 | ||
1da177e4 | 357 | static inline int flock_translate_cmd(int cmd) { |
1da177e4 LT |
358 | switch (cmd) { |
359 | case LOCK_SH: | |
360 | return F_RDLCK; | |
361 | case LOCK_EX: | |
362 | return F_WRLCK; | |
363 | case LOCK_UN: | |
364 | return F_UNLCK; | |
365 | } | |
366 | return -EINVAL; | |
367 | } | |
368 | ||
369 | /* Fill in a file_lock structure with an appropriate FLOCK lock. */ | |
6e129d00 | 370 | static struct file_lock * |
d6367d62 | 371 | flock_make_lock(struct file *filp, unsigned int cmd, struct file_lock *fl) |
1da177e4 | 372 | { |
1da177e4 | 373 | int type = flock_translate_cmd(cmd); |
6e129d00 | 374 | |
1da177e4 | 375 | if (type < 0) |
6e129d00 | 376 | return ERR_PTR(type); |
7bbd1fc0 | 377 | |
d6367d62 N |
378 | if (fl == NULL) { |
379 | fl = locks_alloc_lock(); | |
380 | if (fl == NULL) | |
381 | return ERR_PTR(-ENOMEM); | |
382 | } else { | |
383 | locks_init_lock(fl); | |
384 | } | |
1da177e4 LT |
385 | |
386 | fl->fl_file = filp; | |
73a8f5f7 | 387 | fl->fl_owner = filp; |
1da177e4 LT |
388 | fl->fl_pid = current->tgid; |
389 | fl->fl_flags = FL_FLOCK; | |
390 | fl->fl_type = type; | |
391 | fl->fl_end = OFFSET_MAX; | |
7bbd1fc0 | 392 | |
6e129d00 | 393 | return fl; |
1da177e4 LT |
394 | } |
395 | ||
0ec4f431 | 396 | static int assign_type(struct file_lock *fl, long type) |
1da177e4 LT |
397 | { |
398 | switch (type) { | |
399 | case F_RDLCK: | |
400 | case F_WRLCK: | |
401 | case F_UNLCK: | |
402 | fl->fl_type = type; | |
403 | break; | |
404 | default: | |
405 | return -EINVAL; | |
406 | } | |
407 | return 0; | |
408 | } | |
409 | ||
ef12e72a BF |
410 | static int flock64_to_posix_lock(struct file *filp, struct file_lock *fl, |
411 | struct flock64 *l) | |
1da177e4 | 412 | { |
1da177e4 | 413 | switch (l->l_whence) { |
f5579f8c | 414 | case SEEK_SET: |
ef12e72a | 415 | fl->fl_start = 0; |
1da177e4 | 416 | break; |
f5579f8c | 417 | case SEEK_CUR: |
ef12e72a | 418 | fl->fl_start = filp->f_pos; |
1da177e4 | 419 | break; |
f5579f8c | 420 | case SEEK_END: |
ef12e72a | 421 | fl->fl_start = i_size_read(file_inode(filp)); |
1da177e4 LT |
422 | break; |
423 | default: | |
424 | return -EINVAL; | |
425 | } | |
ef12e72a BF |
426 | if (l->l_start > OFFSET_MAX - fl->fl_start) |
427 | return -EOVERFLOW; | |
428 | fl->fl_start += l->l_start; | |
429 | if (fl->fl_start < 0) | |
430 | return -EINVAL; | |
1da177e4 LT |
431 | |
432 | /* POSIX-1996 leaves the case l->l_len < 0 undefined; | |
433 | POSIX-2001 defines it. */ | |
4c780a46 | 434 | if (l->l_len > 0) { |
ef12e72a BF |
435 | if (l->l_len - 1 > OFFSET_MAX - fl->fl_start) |
436 | return -EOVERFLOW; | |
16238415 | 437 | fl->fl_end = fl->fl_start + (l->l_len - 1); |
ef12e72a | 438 | |
4c780a46 | 439 | } else if (l->l_len < 0) { |
ef12e72a | 440 | if (fl->fl_start + l->l_len < 0) |
4c780a46 | 441 | return -EINVAL; |
ef12e72a BF |
442 | fl->fl_end = fl->fl_start - 1; |
443 | fl->fl_start += l->l_len; | |
444 | } else | |
445 | fl->fl_end = OFFSET_MAX; | |
446 | ||
1da177e4 LT |
447 | fl->fl_owner = current->files; |
448 | fl->fl_pid = current->tgid; | |
449 | fl->fl_file = filp; | |
450 | fl->fl_flags = FL_POSIX; | |
451 | fl->fl_ops = NULL; | |
452 | fl->fl_lmops = NULL; | |
453 | ||
454 | return assign_type(fl, l->l_type); | |
455 | } | |
456 | ||
ef12e72a BF |
457 | /* Verify a "struct flock" and copy it to a "struct file_lock" as a POSIX |
458 | * style lock. | |
459 | */ | |
460 | static int flock_to_posix_lock(struct file *filp, struct file_lock *fl, | |
461 | struct flock *l) | |
1da177e4 | 462 | { |
ef12e72a BF |
463 | struct flock64 ll = { |
464 | .l_type = l->l_type, | |
465 | .l_whence = l->l_whence, | |
466 | .l_start = l->l_start, | |
467 | .l_len = l->l_len, | |
468 | }; | |
469 | ||
470 | return flock64_to_posix_lock(filp, fl, &ll); | |
1da177e4 | 471 | } |
1da177e4 LT |
472 | |
473 | /* default lease lock manager operations */ | |
4d01b7f5 JL |
474 | static bool |
475 | lease_break_callback(struct file_lock *fl) | |
1da177e4 LT |
476 | { |
477 | kill_fasync(&fl->fl_fasync, SIGIO, POLL_MSG); | |
4d01b7f5 | 478 | return false; |
1da177e4 LT |
479 | } |
480 | ||
1c7dd2ff JL |
481 | static void |
482 | lease_setup(struct file_lock *fl, void **priv) | |
483 | { | |
484 | struct file *filp = fl->fl_file; | |
485 | struct fasync_struct *fa = *priv; | |
486 | ||
487 | /* | |
488 | * fasync_insert_entry() returns the old entry if any. If there was no | |
489 | * old entry, then it used "priv" and inserted it into the fasync list. | |
490 | * Clear the pointer to indicate that it shouldn't be freed. | |
491 | */ | |
492 | if (!fasync_insert_entry(fa->fa_fd, filp, &fl->fl_fasync, fa)) | |
493 | *priv = NULL; | |
494 | ||
01919134 | 495 | __f_setown(filp, task_pid(current), PIDTYPE_TGID, 0); |
1c7dd2ff JL |
496 | } |
497 | ||
7b021967 | 498 | static const struct lock_manager_operations lease_manager_ops = { |
8fb47a4f | 499 | .lm_break = lease_break_callback, |
8fb47a4f | 500 | .lm_change = lease_modify, |
1c7dd2ff | 501 | .lm_setup = lease_setup, |
1da177e4 LT |
502 | }; |
503 | ||
504 | /* | |
505 | * Initialize a lease, use the default lock manager operations | |
506 | */ | |
0ec4f431 | 507 | static int lease_init(struct file *filp, long type, struct file_lock *fl) |
447a5647 | 508 | { |
75dff55a TM |
509 | if (assign_type(fl, type) != 0) |
510 | return -EINVAL; | |
511 | ||
7ca76311 | 512 | fl->fl_owner = filp; |
1da177e4 LT |
513 | fl->fl_pid = current->tgid; |
514 | ||
515 | fl->fl_file = filp; | |
516 | fl->fl_flags = FL_LEASE; | |
1da177e4 LT |
517 | fl->fl_start = 0; |
518 | fl->fl_end = OFFSET_MAX; | |
519 | fl->fl_ops = NULL; | |
520 | fl->fl_lmops = &lease_manager_ops; | |
521 | return 0; | |
522 | } | |
523 | ||
524 | /* Allocate a file_lock initialised to this type of lease */ | |
0ec4f431 | 525 | static struct file_lock *lease_alloc(struct file *filp, long type) |
1da177e4 LT |
526 | { |
527 | struct file_lock *fl = locks_alloc_lock(); | |
75dff55a | 528 | int error = -ENOMEM; |
1da177e4 LT |
529 | |
530 | if (fl == NULL) | |
e32b8ee2 | 531 | return ERR_PTR(error); |
1da177e4 LT |
532 | |
533 | error = lease_init(filp, type, fl); | |
75dff55a TM |
534 | if (error) { |
535 | locks_free_lock(fl); | |
e32b8ee2 | 536 | return ERR_PTR(error); |
75dff55a | 537 | } |
e32b8ee2 | 538 | return fl; |
1da177e4 LT |
539 | } |
540 | ||
541 | /* Check if two locks overlap each other. | |
542 | */ | |
543 | static inline int locks_overlap(struct file_lock *fl1, struct file_lock *fl2) | |
544 | { | |
545 | return ((fl1->fl_end >= fl2->fl_start) && | |
546 | (fl2->fl_end >= fl1->fl_start)); | |
547 | } | |
548 | ||
549 | /* | |
550 | * Check whether two locks have the same owner. | |
551 | */ | |
33443c42 | 552 | static int posix_same_owner(struct file_lock *fl1, struct file_lock *fl2) |
1da177e4 | 553 | { |
1da177e4 LT |
554 | return fl1->fl_owner == fl2->fl_owner; |
555 | } | |
556 | ||
6109c850 | 557 | /* Must be called with the flc_lock held! */ |
6ca10ed8 | 558 | static void locks_insert_global_locks(struct file_lock *fl) |
88974691 | 559 | { |
7c3f654d PZ |
560 | struct file_lock_list_struct *fll = this_cpu_ptr(&file_lock_list); |
561 | ||
aba37660 PZ |
562 | percpu_rwsem_assert_held(&file_rwsem); |
563 | ||
7c3f654d | 564 | spin_lock(&fll->lock); |
7012b02a | 565 | fl->fl_link_cpu = smp_processor_id(); |
7c3f654d PZ |
566 | hlist_add_head(&fl->fl_link, &fll->hlist); |
567 | spin_unlock(&fll->lock); | |
88974691 JL |
568 | } |
569 | ||
6109c850 | 570 | /* Must be called with the flc_lock held! */ |
6ca10ed8 | 571 | static void locks_delete_global_locks(struct file_lock *fl) |
88974691 | 572 | { |
7c3f654d PZ |
573 | struct file_lock_list_struct *fll; |
574 | ||
aba37660 PZ |
575 | percpu_rwsem_assert_held(&file_rwsem); |
576 | ||
7012b02a JL |
577 | /* |
578 | * Avoid taking lock if already unhashed. This is safe since this check | |
6109c850 | 579 | * is done while holding the flc_lock, and new insertions into the list |
7012b02a JL |
580 | * also require that it be held. |
581 | */ | |
582 | if (hlist_unhashed(&fl->fl_link)) | |
583 | return; | |
7c3f654d PZ |
584 | |
585 | fll = per_cpu_ptr(&file_lock_list, fl->fl_link_cpu); | |
586 | spin_lock(&fll->lock); | |
139ca04e | 587 | hlist_del_init(&fl->fl_link); |
7c3f654d | 588 | spin_unlock(&fll->lock); |
88974691 JL |
589 | } |
590 | ||
3999e493 JL |
591 | static unsigned long |
592 | posix_owner_key(struct file_lock *fl) | |
593 | { | |
3999e493 JL |
594 | return (unsigned long)fl->fl_owner; |
595 | } | |
596 | ||
6ca10ed8 | 597 | static void locks_insert_global_blocked(struct file_lock *waiter) |
88974691 | 598 | { |
663d5af7 DW |
599 | lockdep_assert_held(&blocked_lock_lock); |
600 | ||
3999e493 | 601 | hash_add(blocked_hash, &waiter->fl_link, posix_owner_key(waiter)); |
88974691 JL |
602 | } |
603 | ||
6ca10ed8 | 604 | static void locks_delete_global_blocked(struct file_lock *waiter) |
88974691 | 605 | { |
663d5af7 DW |
606 | lockdep_assert_held(&blocked_lock_lock); |
607 | ||
48f74186 | 608 | hash_del(&waiter->fl_link); |
88974691 JL |
609 | } |
610 | ||
1da177e4 LT |
611 | /* Remove waiter from blocker's block list. |
612 | * When blocker ends up pointing to itself then the list is empty. | |
1c8c601a | 613 | * |
7b2296af | 614 | * Must be called with blocked_lock_lock held. |
1da177e4 | 615 | */ |
33443c42 | 616 | static void __locks_delete_block(struct file_lock *waiter) |
1da177e4 | 617 | { |
88974691 | 618 | locks_delete_global_blocked(waiter); |
ada5c1da | 619 | list_del_init(&waiter->fl_blocked_member); |
1da177e4 LT |
620 | } |
621 | ||
ad6bbd8b N |
622 | static void __locks_wake_up_blocks(struct file_lock *blocker) |
623 | { | |
624 | while (!list_empty(&blocker->fl_blocked_requests)) { | |
625 | struct file_lock *waiter; | |
626 | ||
627 | waiter = list_first_entry(&blocker->fl_blocked_requests, | |
628 | struct file_lock, fl_blocked_member); | |
629 | __locks_delete_block(waiter); | |
630 | if (waiter->fl_lmops && waiter->fl_lmops->lm_notify) | |
631 | waiter->fl_lmops->lm_notify(waiter); | |
632 | else | |
633 | wake_up(&waiter->fl_wait); | |
dcf23ac3 LT |
634 | |
635 | /* | |
636 | * The setting of fl_blocker to NULL marks the "done" | |
637 | * point in deleting a block. Paired with acquire at the top | |
638 | * of locks_delete_block(). | |
639 | */ | |
640 | smp_store_release(&waiter->fl_blocker, NULL); | |
ad6bbd8b N |
641 | } |
642 | } | |
643 | ||
cb03f94f | 644 | /** |
529adfe8 | 645 | * locks_delete_block - stop waiting for a file lock |
cb03f94f N |
646 | * @waiter: the lock which was waiting |
647 | * | |
648 | * lockd/nfsd need to disconnect the lock while working on it. | |
649 | */ | |
650 | int locks_delete_block(struct file_lock *waiter) | |
1da177e4 | 651 | { |
cb03f94f N |
652 | int status = -ENOENT; |
653 | ||
dcf23ac3 LT |
654 | /* |
655 | * If fl_blocker is NULL, it won't be set again as this thread "owns" | |
656 | * the lock and is the only one that might try to claim the lock. | |
657 | * | |
658 | * We use acquire/release to manage fl_blocker so that we can | |
659 | * optimize away taking the blocked_lock_lock in many cases. | |
660 | * | |
661 | * The smp_load_acquire guarantees two things: | |
662 | * | |
663 | * 1/ that fl_blocked_requests can be tested locklessly. If something | |
664 | * was recently added to that list it must have been in a locked region | |
665 | * *before* the locked region when fl_blocker was set to NULL. | |
666 | * | |
667 | * 2/ that no other thread is accessing 'waiter', so it is safe to free | |
668 | * it. __locks_wake_up_blocks is careful not to touch waiter after | |
669 | * fl_blocker is released. | |
670 | * | |
671 | * If a lockless check of fl_blocker shows it to be NULL, we know that | |
672 | * no new locks can be inserted into its fl_blocked_requests list, and | |
673 | * can avoid doing anything further if the list is empty. | |
674 | */ | |
675 | if (!smp_load_acquire(&waiter->fl_blocker) && | |
676 | list_empty(&waiter->fl_blocked_requests)) | |
677 | return status; | |
678 | ||
7b2296af | 679 | spin_lock(&blocked_lock_lock); |
cb03f94f N |
680 | if (waiter->fl_blocker) |
681 | status = 0; | |
5946c431 | 682 | __locks_wake_up_blocks(waiter); |
1da177e4 | 683 | __locks_delete_block(waiter); |
dcf23ac3 LT |
684 | |
685 | /* | |
686 | * The setting of fl_blocker to NULL marks the "done" point in deleting | |
687 | * a block. Paired with acquire at the top of this function. | |
688 | */ | |
689 | smp_store_release(&waiter->fl_blocker, NULL); | |
7b2296af | 690 | spin_unlock(&blocked_lock_lock); |
cb03f94f | 691 | return status; |
1da177e4 | 692 | } |
cb03f94f | 693 | EXPORT_SYMBOL(locks_delete_block); |
1da177e4 LT |
694 | |
695 | /* Insert waiter into blocker's block list. | |
696 | * We use a circular list so that processes can be easily woken up in | |
697 | * the order they blocked. The documentation doesn't require this but | |
698 | * it seems like the reasonable thing to do. | |
1c8c601a | 699 | * |
6109c850 | 700 | * Must be called with both the flc_lock and blocked_lock_lock held. The |
ada5c1da N |
701 | * fl_blocked_requests list itself is protected by the blocked_lock_lock, |
702 | * but by ensuring that the flc_lock is also held on insertions we can avoid | |
703 | * taking the blocked_lock_lock in some cases when we see that the | |
704 | * fl_blocked_requests list is empty. | |
fd7732e0 N |
705 | * |
706 | * Rather than just adding to the list, we check for conflicts with any existing | |
707 | * waiters, and add beneath any waiter that blocks the new waiter. | |
708 | * Thus wakeups don't happen until needed. | |
1da177e4 | 709 | */ |
1c8c601a | 710 | static void __locks_insert_block(struct file_lock *blocker, |
fd7732e0 N |
711 | struct file_lock *waiter, |
712 | bool conflict(struct file_lock *, | |
713 | struct file_lock *)) | |
1da177e4 | 714 | { |
fd7732e0 | 715 | struct file_lock *fl; |
ada5c1da | 716 | BUG_ON(!list_empty(&waiter->fl_blocked_member)); |
fd7732e0 N |
717 | |
718 | new_blocker: | |
719 | list_for_each_entry(fl, &blocker->fl_blocked_requests, fl_blocked_member) | |
720 | if (conflict(fl, waiter)) { | |
721 | blocker = fl; | |
722 | goto new_blocker; | |
723 | } | |
ada5c1da N |
724 | waiter->fl_blocker = blocker; |
725 | list_add_tail(&waiter->fl_blocked_member, &blocker->fl_blocked_requests); | |
cff2fce5 | 726 | if (IS_POSIX(blocker) && !IS_OFDLCK(blocker)) |
1c8c601a | 727 | locks_insert_global_blocked(waiter); |
5946c431 N |
728 | |
729 | /* The requests in waiter->fl_blocked are known to conflict with | |
730 | * waiter, but might not conflict with blocker, or the requests | |
731 | * and lock which block it. So they all need to be woken. | |
732 | */ | |
733 | __locks_wake_up_blocks(waiter); | |
1c8c601a JL |
734 | } |
735 | ||
6109c850 | 736 | /* Must be called with flc_lock held. */ |
1c8c601a | 737 | static void locks_insert_block(struct file_lock *blocker, |
fd7732e0 N |
738 | struct file_lock *waiter, |
739 | bool conflict(struct file_lock *, | |
740 | struct file_lock *)) | |
1c8c601a | 741 | { |
7b2296af | 742 | spin_lock(&blocked_lock_lock); |
fd7732e0 | 743 | __locks_insert_block(blocker, waiter, conflict); |
7b2296af | 744 | spin_unlock(&blocked_lock_lock); |
1da177e4 LT |
745 | } |
746 | ||
1cb36012 JL |
747 | /* |
748 | * Wake up processes blocked waiting for blocker. | |
749 | * | |
6109c850 | 750 | * Must be called with the inode->flc_lock held! |
1da177e4 LT |
751 | */ |
752 | static void locks_wake_up_blocks(struct file_lock *blocker) | |
753 | { | |
4e8c765d JL |
754 | /* |
755 | * Avoid taking global lock if list is empty. This is safe since new | |
6109c850 | 756 | * blocked requests are only added to the list under the flc_lock, and |
ada5c1da N |
757 | * the flc_lock is always held here. Note that removal from the |
758 | * fl_blocked_requests list does not require the flc_lock, so we must | |
759 | * recheck list_empty() after acquiring the blocked_lock_lock. | |
4e8c765d | 760 | */ |
ada5c1da | 761 | if (list_empty(&blocker->fl_blocked_requests)) |
4e8c765d JL |
762 | return; |
763 | ||
7b2296af | 764 | spin_lock(&blocked_lock_lock); |
ad6bbd8b | 765 | __locks_wake_up_blocks(blocker); |
7b2296af | 766 | spin_unlock(&blocked_lock_lock); |
1da177e4 LT |
767 | } |
768 | ||
5263e31e | 769 | static void |
e084c1bd | 770 | locks_insert_lock_ctx(struct file_lock *fl, struct list_head *before) |
5263e31e | 771 | { |
5263e31e JL |
772 | list_add_tail(&fl->fl_list, before); |
773 | locks_insert_global_locks(fl); | |
774 | } | |
775 | ||
8634b51f | 776 | static void |
e084c1bd | 777 | locks_unlink_lock_ctx(struct file_lock *fl) |
1da177e4 | 778 | { |
88974691 | 779 | locks_delete_global_locks(fl); |
8634b51f | 780 | list_del_init(&fl->fl_list); |
1da177e4 | 781 | locks_wake_up_blocks(fl); |
24cbe784 JL |
782 | } |
783 | ||
8634b51f | 784 | static void |
e084c1bd | 785 | locks_delete_lock_ctx(struct file_lock *fl, struct list_head *dispose) |
24cbe784 | 786 | { |
e084c1bd | 787 | locks_unlink_lock_ctx(fl); |
ed9814d8 | 788 | if (dispose) |
6dee60f6 | 789 | list_add(&fl->fl_list, dispose); |
ed9814d8 JL |
790 | else |
791 | locks_free_lock(fl); | |
1da177e4 LT |
792 | } |
793 | ||
794 | /* Determine if lock sys_fl blocks lock caller_fl. Common functionality | |
795 | * checks for shared/exclusive status of overlapping locks. | |
796 | */ | |
c0e15908 N |
797 | static bool locks_conflict(struct file_lock *caller_fl, |
798 | struct file_lock *sys_fl) | |
1da177e4 LT |
799 | { |
800 | if (sys_fl->fl_type == F_WRLCK) | |
c0e15908 | 801 | return true; |
1da177e4 | 802 | if (caller_fl->fl_type == F_WRLCK) |
c0e15908 N |
803 | return true; |
804 | return false; | |
1da177e4 LT |
805 | } |
806 | ||
807 | /* Determine if lock sys_fl blocks lock caller_fl. POSIX specific | |
808 | * checking before calling the locks_conflict(). | |
809 | */ | |
c0e15908 N |
810 | static bool posix_locks_conflict(struct file_lock *caller_fl, |
811 | struct file_lock *sys_fl) | |
1da177e4 LT |
812 | { |
813 | /* POSIX locks owned by the same process do not conflict with | |
814 | * each other. | |
815 | */ | |
9b8c8695 | 816 | if (posix_same_owner(caller_fl, sys_fl)) |
c0e15908 | 817 | return false; |
1da177e4 LT |
818 | |
819 | /* Check whether they overlap */ | |
820 | if (!locks_overlap(caller_fl, sys_fl)) | |
c0e15908 | 821 | return false; |
1da177e4 | 822 | |
c0e15908 | 823 | return locks_conflict(caller_fl, sys_fl); |
1da177e4 LT |
824 | } |
825 | ||
826 | /* Determine if lock sys_fl blocks lock caller_fl. FLOCK specific | |
827 | * checking before calling the locks_conflict(). | |
828 | */ | |
c0e15908 N |
829 | static bool flock_locks_conflict(struct file_lock *caller_fl, |
830 | struct file_lock *sys_fl) | |
1da177e4 LT |
831 | { |
832 | /* FLOCK locks referring to the same filp do not conflict with | |
833 | * each other. | |
834 | */ | |
9b8c8695 | 835 | if (caller_fl->fl_file == sys_fl->fl_file) |
c0e15908 | 836 | return false; |
1da177e4 | 837 | |
c0e15908 | 838 | return locks_conflict(caller_fl, sys_fl); |
1da177e4 LT |
839 | } |
840 | ||
6d34ac19 | 841 | void |
9d6a8c5c | 842 | posix_test_lock(struct file *filp, struct file_lock *fl) |
1da177e4 LT |
843 | { |
844 | struct file_lock *cfl; | |
bd61e0a9 | 845 | struct file_lock_context *ctx; |
c568d683 | 846 | struct inode *inode = locks_inode(filp); |
1da177e4 | 847 | |
128a3785 | 848 | ctx = smp_load_acquire(&inode->i_flctx); |
bd61e0a9 JL |
849 | if (!ctx || list_empty_careful(&ctx->flc_posix)) { |
850 | fl->fl_type = F_UNLCK; | |
851 | return; | |
852 | } | |
853 | ||
6109c850 | 854 | spin_lock(&ctx->flc_lock); |
bd61e0a9 JL |
855 | list_for_each_entry(cfl, &ctx->flc_posix, fl_list) { |
856 | if (posix_locks_conflict(fl, cfl)) { | |
857 | locks_copy_conflock(fl, cfl); | |
bd61e0a9 JL |
858 | goto out; |
859 | } | |
1da177e4 | 860 | } |
bd61e0a9 JL |
861 | fl->fl_type = F_UNLCK; |
862 | out: | |
6109c850 | 863 | spin_unlock(&ctx->flc_lock); |
6d34ac19 | 864 | return; |
1da177e4 | 865 | } |
1da177e4 LT |
866 | EXPORT_SYMBOL(posix_test_lock); |
867 | ||
b533184f BF |
868 | /* |
869 | * Deadlock detection: | |
870 | * | |
871 | * We attempt to detect deadlocks that are due purely to posix file | |
872 | * locks. | |
1da177e4 | 873 | * |
b533184f BF |
874 | * We assume that a task can be waiting for at most one lock at a time. |
875 | * So for any acquired lock, the process holding that lock may be | |
876 | * waiting on at most one other lock. That lock in turns may be held by | |
877 | * someone waiting for at most one other lock. Given a requested lock | |
878 | * caller_fl which is about to wait for a conflicting lock block_fl, we | |
879 | * follow this chain of waiters to ensure we are not about to create a | |
880 | * cycle. | |
1da177e4 | 881 | * |
b533184f BF |
882 | * Since we do this before we ever put a process to sleep on a lock, we |
883 | * are ensured that there is never a cycle; that is what guarantees that | |
884 | * the while() loop in posix_locks_deadlock() eventually completes. | |
97855b49 | 885 | * |
b533184f BF |
886 | * Note: the above assumption may not be true when handling lock |
887 | * requests from a broken NFS client. It may also fail in the presence | |
888 | * of tasks (such as posix threads) sharing the same open file table. | |
b533184f | 889 | * To handle those cases, we just bail out after a few iterations. |
57b65325 | 890 | * |
cff2fce5 | 891 | * For FL_OFDLCK locks, the owner is the filp, not the files_struct. |
57b65325 JL |
892 | * Because the owner is not even nominally tied to a thread of |
893 | * execution, the deadlock detection below can't reasonably work well. Just | |
894 | * skip it for those. | |
895 | * | |
cff2fce5 | 896 | * In principle, we could do a more limited deadlock detection on FL_OFDLCK |
57b65325 JL |
897 | * locks that just checks for the case where two tasks are attempting to |
898 | * upgrade from read to write locks on the same inode. | |
1da177e4 | 899 | */ |
97855b49 BF |
900 | |
901 | #define MAX_DEADLK_ITERATIONS 10 | |
902 | ||
b533184f BF |
903 | /* Find a lock that the owner of the given block_fl is blocking on. */ |
904 | static struct file_lock *what_owner_is_waiting_for(struct file_lock *block_fl) | |
905 | { | |
906 | struct file_lock *fl; | |
907 | ||
3999e493 | 908 | hash_for_each_possible(blocked_hash, fl, fl_link, posix_owner_key(block_fl)) { |
5946c431 N |
909 | if (posix_same_owner(fl, block_fl)) { |
910 | while (fl->fl_blocker) | |
911 | fl = fl->fl_blocker; | |
912 | return fl; | |
913 | } | |
b533184f BF |
914 | } |
915 | return NULL; | |
916 | } | |
917 | ||
7b2296af | 918 | /* Must be called with the blocked_lock_lock held! */ |
b0904e14 | 919 | static int posix_locks_deadlock(struct file_lock *caller_fl, |
1da177e4 LT |
920 | struct file_lock *block_fl) |
921 | { | |
97855b49 | 922 | int i = 0; |
1da177e4 | 923 | |
663d5af7 DW |
924 | lockdep_assert_held(&blocked_lock_lock); |
925 | ||
57b65325 JL |
926 | /* |
927 | * This deadlock detector can't reasonably detect deadlocks with | |
cff2fce5 | 928 | * FL_OFDLCK locks, since they aren't owned by a process, per-se. |
57b65325 | 929 | */ |
cff2fce5 | 930 | if (IS_OFDLCK(caller_fl)) |
57b65325 JL |
931 | return 0; |
932 | ||
b533184f BF |
933 | while ((block_fl = what_owner_is_waiting_for(block_fl))) { |
934 | if (i++ > MAX_DEADLK_ITERATIONS) | |
935 | return 0; | |
936 | if (posix_same_owner(caller_fl, block_fl)) | |
937 | return 1; | |
1da177e4 LT |
938 | } |
939 | return 0; | |
940 | } | |
941 | ||
1da177e4 | 942 | /* Try to create a FLOCK lock on filp. We always insert new FLOCK locks |
02888f41 | 943 | * after any leases, but before any posix locks. |
f475ae95 TM |
944 | * |
945 | * Note that if called with an FL_EXISTS argument, the caller may determine | |
946 | * whether or not a lock was successfully freed by testing the return | |
947 | * value for -ENOENT. | |
1da177e4 | 948 | */ |
bcd7f78d | 949 | static int flock_lock_inode(struct inode *inode, struct file_lock *request) |
1da177e4 | 950 | { |
993dfa87 | 951 | struct file_lock *new_fl = NULL; |
5263e31e JL |
952 | struct file_lock *fl; |
953 | struct file_lock_context *ctx; | |
1da177e4 | 954 | int error = 0; |
5263e31e | 955 | bool found = false; |
ed9814d8 | 956 | LIST_HEAD(dispose); |
1da177e4 | 957 | |
5c1c669a JL |
958 | ctx = locks_get_lock_context(inode, request->fl_type); |
959 | if (!ctx) { | |
960 | if (request->fl_type != F_UNLCK) | |
961 | return -ENOMEM; | |
962 | return (request->fl_flags & FL_EXISTS) ? -ENOENT : 0; | |
963 | } | |
5263e31e | 964 | |
b89f4321 | 965 | if (!(request->fl_flags & FL_ACCESS) && (request->fl_type != F_UNLCK)) { |
84d535ad | 966 | new_fl = locks_alloc_lock(); |
b89f4321 AB |
967 | if (!new_fl) |
968 | return -ENOMEM; | |
84d535ad PE |
969 | } |
970 | ||
02e525b2 | 971 | percpu_down_read(&file_rwsem); |
6109c850 | 972 | spin_lock(&ctx->flc_lock); |
b89f4321 AB |
973 | if (request->fl_flags & FL_ACCESS) |
974 | goto find_conflict; | |
975 | ||
5263e31e | 976 | list_for_each_entry(fl, &ctx->flc_flock, fl_list) { |
bcd7f78d | 977 | if (request->fl_file != fl->fl_file) |
1da177e4 | 978 | continue; |
993dfa87 | 979 | if (request->fl_type == fl->fl_type) |
1da177e4 | 980 | goto out; |
5263e31e | 981 | found = true; |
e084c1bd | 982 | locks_delete_lock_ctx(fl, &dispose); |
1da177e4 LT |
983 | break; |
984 | } | |
1da177e4 | 985 | |
f475ae95 TM |
986 | if (request->fl_type == F_UNLCK) { |
987 | if ((request->fl_flags & FL_EXISTS) && !found) | |
988 | error = -ENOENT; | |
993dfa87 | 989 | goto out; |
f475ae95 | 990 | } |
1da177e4 | 991 | |
f07f18dd | 992 | find_conflict: |
5263e31e | 993 | list_for_each_entry(fl, &ctx->flc_flock, fl_list) { |
993dfa87 | 994 | if (!flock_locks_conflict(request, fl)) |
1da177e4 LT |
995 | continue; |
996 | error = -EAGAIN; | |
bde74e4b MS |
997 | if (!(request->fl_flags & FL_SLEEP)) |
998 | goto out; | |
999 | error = FILE_LOCK_DEFERRED; | |
fd7732e0 | 1000 | locks_insert_block(fl, request, flock_locks_conflict); |
1da177e4 LT |
1001 | goto out; |
1002 | } | |
f07f18dd TM |
1003 | if (request->fl_flags & FL_ACCESS) |
1004 | goto out; | |
993dfa87 | 1005 | locks_copy_lock(new_fl, request); |
5946c431 | 1006 | locks_move_blocks(new_fl, request); |
e084c1bd | 1007 | locks_insert_lock_ctx(new_fl, &ctx->flc_flock); |
993dfa87 | 1008 | new_fl = NULL; |
9cedc194 | 1009 | error = 0; |
1da177e4 LT |
1010 | |
1011 | out: | |
6109c850 | 1012 | spin_unlock(&ctx->flc_lock); |
02e525b2 | 1013 | percpu_up_read(&file_rwsem); |
993dfa87 TM |
1014 | if (new_fl) |
1015 | locks_free_lock(new_fl); | |
ed9814d8 | 1016 | locks_dispose_list(&dispose); |
c883da31 | 1017 | trace_flock_lock_inode(inode, request, error); |
1da177e4 LT |
1018 | return error; |
1019 | } | |
1020 | ||
b4d629a3 JL |
1021 | static int posix_lock_inode(struct inode *inode, struct file_lock *request, |
1022 | struct file_lock *conflock) | |
1da177e4 | 1023 | { |
bd61e0a9 | 1024 | struct file_lock *fl, *tmp; |
39005d02 MS |
1025 | struct file_lock *new_fl = NULL; |
1026 | struct file_lock *new_fl2 = NULL; | |
1da177e4 LT |
1027 | struct file_lock *left = NULL; |
1028 | struct file_lock *right = NULL; | |
bd61e0a9 | 1029 | struct file_lock_context *ctx; |
b9746ef8 JL |
1030 | int error; |
1031 | bool added = false; | |
ed9814d8 | 1032 | LIST_HEAD(dispose); |
1da177e4 | 1033 | |
5c1c669a | 1034 | ctx = locks_get_lock_context(inode, request->fl_type); |
bd61e0a9 | 1035 | if (!ctx) |
5c1c669a | 1036 | return (request->fl_type == F_UNLCK) ? 0 : -ENOMEM; |
bd61e0a9 | 1037 | |
1da177e4 LT |
1038 | /* |
1039 | * We may need two file_lock structures for this operation, | |
1040 | * so we get them in advance to avoid races. | |
39005d02 MS |
1041 | * |
1042 | * In some cases we can be sure, that no new locks will be needed | |
1da177e4 | 1043 | */ |
39005d02 MS |
1044 | if (!(request->fl_flags & FL_ACCESS) && |
1045 | (request->fl_type != F_UNLCK || | |
1046 | request->fl_start != 0 || request->fl_end != OFFSET_MAX)) { | |
1047 | new_fl = locks_alloc_lock(); | |
1048 | new_fl2 = locks_alloc_lock(); | |
1049 | } | |
1da177e4 | 1050 | |
02e525b2 | 1051 | percpu_down_read(&file_rwsem); |
6109c850 | 1052 | spin_lock(&ctx->flc_lock); |
1cb36012 JL |
1053 | /* |
1054 | * New lock request. Walk all POSIX locks and look for conflicts. If | |
1055 | * there are any, either return error or put the request on the | |
48f74186 | 1056 | * blocker's list of waiters and the global blocked_hash. |
1cb36012 | 1057 | */ |
1da177e4 | 1058 | if (request->fl_type != F_UNLCK) { |
bd61e0a9 | 1059 | list_for_each_entry(fl, &ctx->flc_posix, fl_list) { |
1da177e4 LT |
1060 | if (!posix_locks_conflict(request, fl)) |
1061 | continue; | |
5842add2 | 1062 | if (conflock) |
3fe0fff1 | 1063 | locks_copy_conflock(conflock, fl); |
1da177e4 LT |
1064 | error = -EAGAIN; |
1065 | if (!(request->fl_flags & FL_SLEEP)) | |
1066 | goto out; | |
1c8c601a JL |
1067 | /* |
1068 | * Deadlock detection and insertion into the blocked | |
1069 | * locks list must be done while holding the same lock! | |
1070 | */ | |
1da177e4 | 1071 | error = -EDEADLK; |
7b2296af | 1072 | spin_lock(&blocked_lock_lock); |
945ab8f6 JL |
1073 | /* |
1074 | * Ensure that we don't find any locks blocked on this | |
1075 | * request during deadlock detection. | |
1076 | */ | |
1077 | __locks_wake_up_blocks(request); | |
1c8c601a JL |
1078 | if (likely(!posix_locks_deadlock(request, fl))) { |
1079 | error = FILE_LOCK_DEFERRED; | |
fd7732e0 N |
1080 | __locks_insert_block(fl, request, |
1081 | posix_locks_conflict); | |
1c8c601a | 1082 | } |
7b2296af | 1083 | spin_unlock(&blocked_lock_lock); |
1da177e4 | 1084 | goto out; |
7bbd1fc0 N |
1085 | } |
1086 | } | |
1da177e4 LT |
1087 | |
1088 | /* If we're just looking for a conflict, we're done. */ | |
1089 | error = 0; | |
1090 | if (request->fl_flags & FL_ACCESS) | |
1091 | goto out; | |
1092 | ||
bd61e0a9 JL |
1093 | /* Find the first old lock with the same owner as the new lock */ |
1094 | list_for_each_entry(fl, &ctx->flc_posix, fl_list) { | |
1095 | if (posix_same_owner(request, fl)) | |
1096 | break; | |
1da177e4 LT |
1097 | } |
1098 | ||
1cb36012 | 1099 | /* Process locks with this owner. */ |
bd61e0a9 JL |
1100 | list_for_each_entry_safe_from(fl, tmp, &ctx->flc_posix, fl_list) { |
1101 | if (!posix_same_owner(request, fl)) | |
1102 | break; | |
1103 | ||
1104 | /* Detect adjacent or overlapping regions (if same lock type) */ | |
1da177e4 | 1105 | if (request->fl_type == fl->fl_type) { |
449231d6 OK |
1106 | /* In all comparisons of start vs end, use |
1107 | * "start - 1" rather than "end + 1". If end | |
1108 | * is OFFSET_MAX, end + 1 will become negative. | |
1109 | */ | |
1da177e4 | 1110 | if (fl->fl_end < request->fl_start - 1) |
bd61e0a9 | 1111 | continue; |
1da177e4 LT |
1112 | /* If the next lock in the list has entirely bigger |
1113 | * addresses than the new one, insert the lock here. | |
1114 | */ | |
449231d6 | 1115 | if (fl->fl_start - 1 > request->fl_end) |
1da177e4 LT |
1116 | break; |
1117 | ||
1118 | /* If we come here, the new and old lock are of the | |
1119 | * same type and adjacent or overlapping. Make one | |
1120 | * lock yielding from the lower start address of both | |
1121 | * locks to the higher end address. | |
1122 | */ | |
1123 | if (fl->fl_start > request->fl_start) | |
1124 | fl->fl_start = request->fl_start; | |
1125 | else | |
1126 | request->fl_start = fl->fl_start; | |
1127 | if (fl->fl_end < request->fl_end) | |
1128 | fl->fl_end = request->fl_end; | |
1129 | else | |
1130 | request->fl_end = fl->fl_end; | |
1131 | if (added) { | |
e084c1bd | 1132 | locks_delete_lock_ctx(fl, &dispose); |
1da177e4 LT |
1133 | continue; |
1134 | } | |
1135 | request = fl; | |
b9746ef8 | 1136 | added = true; |
bd61e0a9 | 1137 | } else { |
1da177e4 LT |
1138 | /* Processing for different lock types is a bit |
1139 | * more complex. | |
1140 | */ | |
1141 | if (fl->fl_end < request->fl_start) | |
bd61e0a9 | 1142 | continue; |
1da177e4 LT |
1143 | if (fl->fl_start > request->fl_end) |
1144 | break; | |
1145 | if (request->fl_type == F_UNLCK) | |
b9746ef8 | 1146 | added = true; |
1da177e4 LT |
1147 | if (fl->fl_start < request->fl_start) |
1148 | left = fl; | |
1149 | /* If the next lock in the list has a higher end | |
1150 | * address than the new one, insert the new one here. | |
1151 | */ | |
1152 | if (fl->fl_end > request->fl_end) { | |
1153 | right = fl; | |
1154 | break; | |
1155 | } | |
1156 | if (fl->fl_start >= request->fl_start) { | |
1157 | /* The new lock completely replaces an old | |
1158 | * one (This may happen several times). | |
1159 | */ | |
1160 | if (added) { | |
e084c1bd | 1161 | locks_delete_lock_ctx(fl, &dispose); |
1da177e4 LT |
1162 | continue; |
1163 | } | |
b84d49f9 JL |
1164 | /* |
1165 | * Replace the old lock with new_fl, and | |
1166 | * remove the old one. It's safe to do the | |
1167 | * insert here since we know that we won't be | |
1168 | * using new_fl later, and that the lock is | |
1169 | * just replacing an existing lock. | |
1da177e4 | 1170 | */ |
b84d49f9 JL |
1171 | error = -ENOLCK; |
1172 | if (!new_fl) | |
1173 | goto out; | |
1174 | locks_copy_lock(new_fl, request); | |
5ef15968 | 1175 | locks_move_blocks(new_fl, request); |
b84d49f9 JL |
1176 | request = new_fl; |
1177 | new_fl = NULL; | |
e084c1bd JL |
1178 | locks_insert_lock_ctx(request, &fl->fl_list); |
1179 | locks_delete_lock_ctx(fl, &dispose); | |
b9746ef8 | 1180 | added = true; |
1da177e4 LT |
1181 | } |
1182 | } | |
1da177e4 LT |
1183 | } |
1184 | ||
0d9a490a | 1185 | /* |
1cb36012 JL |
1186 | * The above code only modifies existing locks in case of merging or |
1187 | * replacing. If new lock(s) need to be inserted all modifications are | |
1188 | * done below this, so it's safe yet to bail out. | |
0d9a490a MS |
1189 | */ |
1190 | error = -ENOLCK; /* "no luck" */ | |
1191 | if (right && left == right && !new_fl2) | |
1192 | goto out; | |
1193 | ||
1da177e4 LT |
1194 | error = 0; |
1195 | if (!added) { | |
f475ae95 TM |
1196 | if (request->fl_type == F_UNLCK) { |
1197 | if (request->fl_flags & FL_EXISTS) | |
1198 | error = -ENOENT; | |
1da177e4 | 1199 | goto out; |
f475ae95 | 1200 | } |
0d9a490a MS |
1201 | |
1202 | if (!new_fl) { | |
1203 | error = -ENOLCK; | |
1204 | goto out; | |
1205 | } | |
1da177e4 | 1206 | locks_copy_lock(new_fl, request); |
5946c431 | 1207 | locks_move_blocks(new_fl, request); |
e084c1bd | 1208 | locks_insert_lock_ctx(new_fl, &fl->fl_list); |
2e2f756f | 1209 | fl = new_fl; |
1da177e4 LT |
1210 | new_fl = NULL; |
1211 | } | |
1212 | if (right) { | |
1213 | if (left == right) { | |
1214 | /* The new lock breaks the old one in two pieces, | |
1215 | * so we have to use the second new lock. | |
1216 | */ | |
1217 | left = new_fl2; | |
1218 | new_fl2 = NULL; | |
1219 | locks_copy_lock(left, right); | |
e084c1bd | 1220 | locks_insert_lock_ctx(left, &fl->fl_list); |
1da177e4 LT |
1221 | } |
1222 | right->fl_start = request->fl_end + 1; | |
1223 | locks_wake_up_blocks(right); | |
1224 | } | |
1225 | if (left) { | |
1226 | left->fl_end = request->fl_start - 1; | |
1227 | locks_wake_up_blocks(left); | |
1228 | } | |
1229 | out: | |
6109c850 | 1230 | spin_unlock(&ctx->flc_lock); |
02e525b2 | 1231 | percpu_up_read(&file_rwsem); |
1da177e4 LT |
1232 | /* |
1233 | * Free any unused locks. | |
1234 | */ | |
1235 | if (new_fl) | |
1236 | locks_free_lock(new_fl); | |
1237 | if (new_fl2) | |
1238 | locks_free_lock(new_fl2); | |
ed9814d8 | 1239 | locks_dispose_list(&dispose); |
1890910f JL |
1240 | trace_posix_lock_inode(inode, request, error); |
1241 | ||
1da177e4 LT |
1242 | return error; |
1243 | } | |
1244 | ||
1245 | /** | |
1246 | * posix_lock_file - Apply a POSIX-style lock to a file | |
1247 | * @filp: The file to apply the lock to | |
1248 | * @fl: The lock to be applied | |
150b3934 | 1249 | * @conflock: Place to return a copy of the conflicting lock, if found. |
1da177e4 LT |
1250 | * |
1251 | * Add a POSIX style lock to a file. | |
1252 | * We merge adjacent & overlapping locks whenever possible. | |
1253 | * POSIX locks are sorted by owner task, then by starting address | |
f475ae95 TM |
1254 | * |
1255 | * Note that if called with an FL_EXISTS argument, the caller may determine | |
1256 | * whether or not a lock was successfully freed by testing the return | |
1257 | * value for -ENOENT. | |
1da177e4 | 1258 | */ |
150b3934 | 1259 | int posix_lock_file(struct file *filp, struct file_lock *fl, |
5842add2 AA |
1260 | struct file_lock *conflock) |
1261 | { | |
c568d683 | 1262 | return posix_lock_inode(locks_inode(filp), fl, conflock); |
1da177e4 | 1263 | } |
150b3934 | 1264 | EXPORT_SYMBOL(posix_lock_file); |
1da177e4 LT |
1265 | |
1266 | /** | |
29d01b22 JL |
1267 | * posix_lock_inode_wait - Apply a POSIX-style lock to a file |
1268 | * @inode: inode of file to which lock request should be applied | |
1da177e4 LT |
1269 | * @fl: The lock to be applied |
1270 | * | |
616fb38f | 1271 | * Apply a POSIX style lock request to an inode. |
1da177e4 | 1272 | */ |
616fb38f | 1273 | static int posix_lock_inode_wait(struct inode *inode, struct file_lock *fl) |
1da177e4 LT |
1274 | { |
1275 | int error; | |
1276 | might_sleep (); | |
1277 | for (;;) { | |
b4d629a3 | 1278 | error = posix_lock_inode(inode, fl, NULL); |
bde74e4b | 1279 | if (error != FILE_LOCK_DEFERRED) |
1da177e4 | 1280 | break; |
dcf23ac3 LT |
1281 | error = wait_event_interruptible(fl->fl_wait, |
1282 | list_empty(&fl->fl_blocked_member)); | |
16306a61 N |
1283 | if (error) |
1284 | break; | |
1da177e4 | 1285 | } |
16306a61 | 1286 | locks_delete_block(fl); |
1da177e4 LT |
1287 | return error; |
1288 | } | |
29d01b22 | 1289 | |
778fc546 BF |
1290 | static void lease_clear_pending(struct file_lock *fl, int arg) |
1291 | { | |
1292 | switch (arg) { | |
1293 | case F_UNLCK: | |
1294 | fl->fl_flags &= ~FL_UNLOCK_PENDING; | |
df561f66 | 1295 | fallthrough; |
778fc546 BF |
1296 | case F_RDLCK: |
1297 | fl->fl_flags &= ~FL_DOWNGRADE_PENDING; | |
1298 | } | |
1299 | } | |
1300 | ||
1da177e4 | 1301 | /* We already had a lease on this file; just change its type */ |
7448cc37 | 1302 | int lease_modify(struct file_lock *fl, int arg, struct list_head *dispose) |
1da177e4 | 1303 | { |
1da177e4 LT |
1304 | int error = assign_type(fl, arg); |
1305 | ||
1306 | if (error) | |
1307 | return error; | |
778fc546 | 1308 | lease_clear_pending(fl, arg); |
1da177e4 | 1309 | locks_wake_up_blocks(fl); |
3b6e2723 FB |
1310 | if (arg == F_UNLCK) { |
1311 | struct file *filp = fl->fl_file; | |
1312 | ||
1313 | f_delown(filp); | |
1314 | filp->f_owner.signum = 0; | |
96d6d59c BF |
1315 | fasync_helper(0, fl->fl_file, 0, &fl->fl_fasync); |
1316 | if (fl->fl_fasync != NULL) { | |
1317 | printk(KERN_ERR "locks_delete_lock: fasync == %p\n", fl->fl_fasync); | |
1318 | fl->fl_fasync = NULL; | |
1319 | } | |
e084c1bd | 1320 | locks_delete_lock_ctx(fl, dispose); |
3b6e2723 | 1321 | } |
1da177e4 LT |
1322 | return 0; |
1323 | } | |
1da177e4 LT |
1324 | EXPORT_SYMBOL(lease_modify); |
1325 | ||
778fc546 BF |
1326 | static bool past_time(unsigned long then) |
1327 | { | |
1328 | if (!then) | |
1329 | /* 0 is a special value meaning "this never expires": */ | |
1330 | return false; | |
1331 | return time_after(jiffies, then); | |
1332 | } | |
1333 | ||
c45198ed | 1334 | static void time_out_leases(struct inode *inode, struct list_head *dispose) |
1da177e4 | 1335 | { |
8634b51f JL |
1336 | struct file_lock_context *ctx = inode->i_flctx; |
1337 | struct file_lock *fl, *tmp; | |
1da177e4 | 1338 | |
6109c850 | 1339 | lockdep_assert_held(&ctx->flc_lock); |
f82b4b67 | 1340 | |
8634b51f | 1341 | list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list) { |
62af4f1f | 1342 | trace_time_out_leases(inode, fl); |
778fc546 | 1343 | if (past_time(fl->fl_downgrade_time)) |
7448cc37 | 1344 | lease_modify(fl, F_RDLCK, dispose); |
778fc546 | 1345 | if (past_time(fl->fl_break_time)) |
7448cc37 | 1346 | lease_modify(fl, F_UNLCK, dispose); |
1da177e4 LT |
1347 | } |
1348 | } | |
1349 | ||
df4e8d2c BF |
1350 | static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker) |
1351 | { | |
d51f527f IW |
1352 | bool rc; |
1353 | ||
28df3d15 BF |
1354 | if (lease->fl_lmops->lm_breaker_owns_lease |
1355 | && lease->fl_lmops->lm_breaker_owns_lease(lease)) | |
1356 | return false; | |
d51f527f IW |
1357 | if ((breaker->fl_flags & FL_LAYOUT) != (lease->fl_flags & FL_LAYOUT)) { |
1358 | rc = false; | |
1359 | goto trace; | |
1360 | } | |
1361 | if ((breaker->fl_flags & FL_DELEG) && (lease->fl_flags & FL_LEASE)) { | |
1362 | rc = false; | |
1363 | goto trace; | |
1364 | } | |
1365 | ||
1366 | rc = locks_conflict(breaker, lease); | |
1367 | trace: | |
1368 | trace_leases_conflict(rc, lease, breaker); | |
1369 | return rc; | |
df4e8d2c BF |
1370 | } |
1371 | ||
03d12ddf JL |
1372 | static bool |
1373 | any_leases_conflict(struct inode *inode, struct file_lock *breaker) | |
1374 | { | |
8634b51f | 1375 | struct file_lock_context *ctx = inode->i_flctx; |
03d12ddf JL |
1376 | struct file_lock *fl; |
1377 | ||
6109c850 | 1378 | lockdep_assert_held(&ctx->flc_lock); |
03d12ddf | 1379 | |
8634b51f | 1380 | list_for_each_entry(fl, &ctx->flc_lease, fl_list) { |
03d12ddf JL |
1381 | if (leases_conflict(fl, breaker)) |
1382 | return true; | |
1383 | } | |
1384 | return false; | |
1385 | } | |
1386 | ||
1da177e4 LT |
1387 | /** |
1388 | * __break_lease - revoke all outstanding leases on file | |
1389 | * @inode: the inode of the file to return | |
df4e8d2c BF |
1390 | * @mode: O_RDONLY: break only write leases; O_WRONLY or O_RDWR: |
1391 | * break all leases | |
1392 | * @type: FL_LEASE: break leases and delegations; FL_DELEG: break | |
1393 | * only delegations | |
1da177e4 | 1394 | * |
87250dd2 | 1395 | * break_lease (inlined for speed) has checked there already is at least |
1396 | * some kind of lock (maybe a lease) on this file. Leases are broken on | |
1397 | * a call to open() or truncate(). This function can sleep unless you | |
1da177e4 LT |
1398 | * specified %O_NONBLOCK to your open(). |
1399 | */ | |
df4e8d2c | 1400 | int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) |
1da177e4 | 1401 | { |
778fc546 | 1402 | int error = 0; |
128a3785 | 1403 | struct file_lock_context *ctx; |
a901125c | 1404 | struct file_lock *new_fl, *fl, *tmp; |
1da177e4 | 1405 | unsigned long break_time; |
8737c930 | 1406 | int want_write = (mode & O_ACCMODE) != O_RDONLY; |
c45198ed | 1407 | LIST_HEAD(dispose); |
1da177e4 | 1408 | |
8737c930 | 1409 | new_fl = lease_alloc(NULL, want_write ? F_WRLCK : F_RDLCK); |
6d4b9e38 LT |
1410 | if (IS_ERR(new_fl)) |
1411 | return PTR_ERR(new_fl); | |
df4e8d2c | 1412 | new_fl->fl_flags = type; |
1da177e4 | 1413 | |
8634b51f | 1414 | /* typically we will check that ctx is non-NULL before calling */ |
128a3785 | 1415 | ctx = smp_load_acquire(&inode->i_flctx); |
8634b51f JL |
1416 | if (!ctx) { |
1417 | WARN_ON_ONCE(1); | |
cfddf9f4 | 1418 | goto free_lock; |
8634b51f JL |
1419 | } |
1420 | ||
02e525b2 | 1421 | percpu_down_read(&file_rwsem); |
6109c850 | 1422 | spin_lock(&ctx->flc_lock); |
1da177e4 | 1423 | |
c45198ed | 1424 | time_out_leases(inode, &dispose); |
1da177e4 | 1425 | |
03d12ddf | 1426 | if (!any_leases_conflict(inode, new_fl)) |
778fc546 BF |
1427 | goto out; |
1428 | ||
1da177e4 LT |
1429 | break_time = 0; |
1430 | if (lease_break_time > 0) { | |
1431 | break_time = jiffies + lease_break_time * HZ; | |
1432 | if (break_time == 0) | |
1433 | break_time++; /* so that 0 means no break time */ | |
1434 | } | |
1435 | ||
a901125c | 1436 | list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list) { |
df4e8d2c BF |
1437 | if (!leases_conflict(fl, new_fl)) |
1438 | continue; | |
778fc546 BF |
1439 | if (want_write) { |
1440 | if (fl->fl_flags & FL_UNLOCK_PENDING) | |
1441 | continue; | |
1442 | fl->fl_flags |= FL_UNLOCK_PENDING; | |
1da177e4 | 1443 | fl->fl_break_time = break_time; |
778fc546 | 1444 | } else { |
8634b51f | 1445 | if (lease_breaking(fl)) |
778fc546 BF |
1446 | continue; |
1447 | fl->fl_flags |= FL_DOWNGRADE_PENDING; | |
1448 | fl->fl_downgrade_time = break_time; | |
1da177e4 | 1449 | } |
4d01b7f5 | 1450 | if (fl->fl_lmops->lm_break(fl)) |
e084c1bd | 1451 | locks_delete_lock_ctx(fl, &dispose); |
1da177e4 LT |
1452 | } |
1453 | ||
8634b51f | 1454 | if (list_empty(&ctx->flc_lease)) |
4d01b7f5 JL |
1455 | goto out; |
1456 | ||
843c6b2f | 1457 | if (mode & O_NONBLOCK) { |
62af4f1f | 1458 | trace_break_lease_noblock(inode, new_fl); |
1da177e4 LT |
1459 | error = -EWOULDBLOCK; |
1460 | goto out; | |
1461 | } | |
1462 | ||
1463 | restart: | |
8634b51f JL |
1464 | fl = list_first_entry(&ctx->flc_lease, struct file_lock, fl_list); |
1465 | break_time = fl->fl_break_time; | |
f1c6bb2c | 1466 | if (break_time != 0) |
1da177e4 | 1467 | break_time -= jiffies; |
f1c6bb2c JL |
1468 | if (break_time == 0) |
1469 | break_time++; | |
fd7732e0 | 1470 | locks_insert_block(fl, new_fl, leases_conflict); |
62af4f1f | 1471 | trace_break_lease_block(inode, new_fl); |
6109c850 | 1472 | spin_unlock(&ctx->flc_lock); |
02e525b2 | 1473 | percpu_up_read(&file_rwsem); |
aba37660 | 1474 | |
c45198ed | 1475 | locks_dispose_list(&dispose); |
4321e01e | 1476 | error = wait_event_interruptible_timeout(new_fl->fl_wait, |
dcf23ac3 LT |
1477 | list_empty(&new_fl->fl_blocked_member), |
1478 | break_time); | |
aba37660 | 1479 | |
02e525b2 | 1480 | percpu_down_read(&file_rwsem); |
6109c850 | 1481 | spin_lock(&ctx->flc_lock); |
62af4f1f | 1482 | trace_break_lease_unblock(inode, new_fl); |
1c8c601a | 1483 | locks_delete_block(new_fl); |
1da177e4 | 1484 | if (error >= 0) { |
778fc546 BF |
1485 | /* |
1486 | * Wait for the next conflicting lease that has not been | |
1487 | * broken yet | |
1488 | */ | |
03d12ddf JL |
1489 | if (error == 0) |
1490 | time_out_leases(inode, &dispose); | |
1491 | if (any_leases_conflict(inode, new_fl)) | |
1492 | goto restart; | |
1da177e4 LT |
1493 | error = 0; |
1494 | } | |
1da177e4 | 1495 | out: |
6109c850 | 1496 | spin_unlock(&ctx->flc_lock); |
02e525b2 | 1497 | percpu_up_read(&file_rwsem); |
c45198ed | 1498 | locks_dispose_list(&dispose); |
cfddf9f4 | 1499 | free_lock: |
6d4b9e38 | 1500 | locks_free_lock(new_fl); |
1da177e4 LT |
1501 | return error; |
1502 | } | |
1da177e4 LT |
1503 | EXPORT_SYMBOL(__break_lease); |
1504 | ||
1505 | /** | |
76c47948 | 1506 | * lease_get_mtime - update modified time of an inode with exclusive lease |
1da177e4 | 1507 | * @inode: the inode |
76c47948 | 1508 | * @time: pointer to a timespec which contains the last modified time |
1da177e4 LT |
1509 | * |
1510 | * This is to force NFS clients to flush their caches for files with | |
1511 | * exclusive leases. The justification is that if someone has an | |
a6b91919 | 1512 | * exclusive lease, then they could be modifying it. |
1da177e4 | 1513 | */ |
95582b00 | 1514 | void lease_get_mtime(struct inode *inode, struct timespec64 *time) |
1da177e4 | 1515 | { |
bfe86024 | 1516 | bool has_lease = false; |
128a3785 | 1517 | struct file_lock_context *ctx; |
8634b51f | 1518 | struct file_lock *fl; |
bfe86024 | 1519 | |
128a3785 | 1520 | ctx = smp_load_acquire(&inode->i_flctx); |
8634b51f | 1521 | if (ctx && !list_empty_careful(&ctx->flc_lease)) { |
6109c850 | 1522 | spin_lock(&ctx->flc_lock); |
8ace5dfb GT |
1523 | fl = list_first_entry_or_null(&ctx->flc_lease, |
1524 | struct file_lock, fl_list); | |
1525 | if (fl && (fl->fl_type == F_WRLCK)) | |
1526 | has_lease = true; | |
6109c850 | 1527 | spin_unlock(&ctx->flc_lock); |
bfe86024 JL |
1528 | } |
1529 | ||
1530 | if (has_lease) | |
c2050a45 | 1531 | *time = current_time(inode); |
1da177e4 | 1532 | } |
1da177e4 LT |
1533 | EXPORT_SYMBOL(lease_get_mtime); |
1534 | ||
1535 | /** | |
1536 | * fcntl_getlease - Enquire what lease is currently active | |
1537 | * @filp: the file | |
1538 | * | |
1539 | * The value returned by this function will be one of | |
1540 | * (if no lease break is pending): | |
1541 | * | |
1542 | * %F_RDLCK to indicate a shared lease is held. | |
1543 | * | |
1544 | * %F_WRLCK to indicate an exclusive lease is held. | |
1545 | * | |
1546 | * %F_UNLCK to indicate no lease is held. | |
1547 | * | |
1548 | * (if a lease break is pending): | |
1549 | * | |
1550 | * %F_RDLCK to indicate an exclusive lease needs to be | |
1551 | * changed to a shared lease (or removed). | |
1552 | * | |
1553 | * %F_UNLCK to indicate the lease needs to be removed. | |
1554 | * | |
1555 | * XXX: sfr & willy disagree over whether F_INPROGRESS | |
1556 | * should be returned to userspace. | |
1557 | */ | |
1558 | int fcntl_getlease(struct file *filp) | |
1559 | { | |
1560 | struct file_lock *fl; | |
c568d683 | 1561 | struct inode *inode = locks_inode(filp); |
128a3785 | 1562 | struct file_lock_context *ctx; |
1da177e4 | 1563 | int type = F_UNLCK; |
c45198ed | 1564 | LIST_HEAD(dispose); |
1da177e4 | 1565 | |
128a3785 | 1566 | ctx = smp_load_acquire(&inode->i_flctx); |
8634b51f | 1567 | if (ctx && !list_empty_careful(&ctx->flc_lease)) { |
02e525b2 | 1568 | percpu_down_read(&file_rwsem); |
6109c850 | 1569 | spin_lock(&ctx->flc_lock); |
c568d683 | 1570 | time_out_leases(inode, &dispose); |
8634b51f JL |
1571 | list_for_each_entry(fl, &ctx->flc_lease, fl_list) { |
1572 | if (fl->fl_file != filp) | |
1573 | continue; | |
778fc546 | 1574 | type = target_leasetype(fl); |
1da177e4 LT |
1575 | break; |
1576 | } | |
6109c850 | 1577 | spin_unlock(&ctx->flc_lock); |
02e525b2 | 1578 | percpu_up_read(&file_rwsem); |
5f43086b | 1579 | |
8634b51f | 1580 | locks_dispose_list(&dispose); |
1da177e4 | 1581 | } |
1da177e4 LT |
1582 | return type; |
1583 | } | |
1584 | ||
24cbe784 | 1585 | /** |
387e3746 | 1586 | * check_conflicting_open - see if the given file points to an inode that has |
7bbd1fc0 N |
1587 | * an existing open that would conflict with the |
1588 | * desired lease. | |
387e3746 | 1589 | * @filp: file to check |
24cbe784 | 1590 | * @arg: type of lease that we're trying to acquire |
7fadc59c | 1591 | * @flags: current lock flags |
24cbe784 JL |
1592 | * |
1593 | * Check to see if there's an existing open fd on this file that would | |
1594 | * conflict with the lease we're trying to set. | |
1595 | */ | |
1596 | static int | |
387e3746 | 1597 | check_conflicting_open(struct file *filp, const long arg, int flags) |
24cbe784 | 1598 | { |
387e3746 AG |
1599 | struct inode *inode = locks_inode(filp); |
1600 | int self_wcount = 0, self_rcount = 0; | |
24cbe784 | 1601 | |
11afe9f7 CH |
1602 | if (flags & FL_LAYOUT) |
1603 | return 0; | |
aba2072f BF |
1604 | if (flags & FL_DELEG) |
1605 | /* We leave these checks to the caller */ | |
1606 | return 0; | |
11afe9f7 | 1607 | |
387e3746 AG |
1608 | if (arg == F_RDLCK) |
1609 | return inode_is_open_for_write(inode) ? -EAGAIN : 0; | |
1610 | else if (arg != F_WRLCK) | |
1611 | return 0; | |
1612 | ||
1613 | /* | |
1614 | * Make sure that only read/write count is from lease requestor. | |
1615 | * Note that this will result in denying write leases when i_writecount | |
1616 | * is negative, which is what we want. (We shouldn't grant write leases | |
1617 | * on files open for execution.) | |
1618 | */ | |
1619 | if (filp->f_mode & FMODE_WRITE) | |
1620 | self_wcount = 1; | |
1621 | else if (filp->f_mode & FMODE_READ) | |
1622 | self_rcount = 1; | |
24cbe784 | 1623 | |
387e3746 AG |
1624 | if (atomic_read(&inode->i_writecount) != self_wcount || |
1625 | atomic_read(&inode->i_readcount) != self_rcount) | |
1626 | return -EAGAIN; | |
24cbe784 | 1627 | |
387e3746 | 1628 | return 0; |
24cbe784 JL |
1629 | } |
1630 | ||
e6f5c789 JL |
1631 | static int |
1632 | generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **priv) | |
1da177e4 | 1633 | { |
8634b51f | 1634 | struct file_lock *fl, *my_fl = NULL, *lease; |
387e3746 | 1635 | struct inode *inode = locks_inode(filp); |
8634b51f | 1636 | struct file_lock_context *ctx; |
df4e8d2c | 1637 | bool is_deleg = (*flp)->fl_flags & FL_DELEG; |
c1f24ef4 | 1638 | int error; |
c45198ed | 1639 | LIST_HEAD(dispose); |
1da177e4 | 1640 | |
096657b6 | 1641 | lease = *flp; |
62af4f1f JL |
1642 | trace_generic_add_lease(inode, lease); |
1643 | ||
5c1c669a JL |
1644 | /* Note that arg is never F_UNLCK here */ |
1645 | ctx = locks_get_lock_context(inode, arg); | |
8634b51f JL |
1646 | if (!ctx) |
1647 | return -ENOMEM; | |
1648 | ||
df4e8d2c BF |
1649 | /* |
1650 | * In the delegation case we need mutual exclusion with | |
1651 | * a number of operations that take the i_mutex. We trylock | |
1652 | * because delegations are an optional optimization, and if | |
1653 | * there's some chance of a conflict--we'd rather not | |
1654 | * bother, maybe that's a sign this just isn't a good file to | |
1655 | * hand out a delegation on. | |
1656 | */ | |
5955102c | 1657 | if (is_deleg && !inode_trylock(inode)) |
df4e8d2c BF |
1658 | return -EAGAIN; |
1659 | ||
1660 | if (is_deleg && arg == F_WRLCK) { | |
1661 | /* Write delegations are not currently supported: */ | |
5955102c | 1662 | inode_unlock(inode); |
df4e8d2c BF |
1663 | WARN_ON_ONCE(1); |
1664 | return -EINVAL; | |
1665 | } | |
096657b6 | 1666 | |
02e525b2 | 1667 | percpu_down_read(&file_rwsem); |
6109c850 | 1668 | spin_lock(&ctx->flc_lock); |
c45198ed | 1669 | time_out_leases(inode, &dispose); |
387e3746 | 1670 | error = check_conflicting_open(filp, arg, lease->fl_flags); |
24cbe784 | 1671 | if (error) |
096657b6 | 1672 | goto out; |
6d5e8b05 | 1673 | |
1da177e4 LT |
1674 | /* |
1675 | * At this point, we know that if there is an exclusive | |
1676 | * lease on this file, then we hold it on this filp | |
1677 | * (otherwise our open of this file would have blocked). | |
1678 | * And if we are trying to acquire an exclusive lease, | |
1679 | * then the file is not open by anyone (including us) | |
1680 | * except for this filp. | |
1681 | */ | |
c1f24ef4 | 1682 | error = -EAGAIN; |
8634b51f | 1683 | list_for_each_entry(fl, &ctx->flc_lease, fl_list) { |
2ab99ee1 CH |
1684 | if (fl->fl_file == filp && |
1685 | fl->fl_owner == lease->fl_owner) { | |
8634b51f | 1686 | my_fl = fl; |
c1f24ef4 BF |
1687 | continue; |
1688 | } | |
8634b51f | 1689 | |
c1f24ef4 BF |
1690 | /* |
1691 | * No exclusive leases if someone else has a lease on | |
1692 | * this file: | |
1693 | */ | |
1694 | if (arg == F_WRLCK) | |
1695 | goto out; | |
1696 | /* | |
1697 | * Modifying our existing lease is OK, but no getting a | |
1698 | * new lease if someone else is opening for write: | |
1699 | */ | |
1700 | if (fl->fl_flags & FL_UNLOCK_PENDING) | |
1701 | goto out; | |
1da177e4 LT |
1702 | } |
1703 | ||
8634b51f | 1704 | if (my_fl != NULL) { |
0164bf02 JL |
1705 | lease = my_fl; |
1706 | error = lease->fl_lmops->lm_change(lease, arg, &dispose); | |
1c7dd2ff JL |
1707 | if (error) |
1708 | goto out; | |
1709 | goto out_setup; | |
1da177e4 LT |
1710 | } |
1711 | ||
1da177e4 LT |
1712 | error = -EINVAL; |
1713 | if (!leases_enable) | |
1714 | goto out; | |
1715 | ||
e084c1bd | 1716 | locks_insert_lock_ctx(lease, &ctx->flc_lease); |
24cbe784 JL |
1717 | /* |
1718 | * The check in break_lease() is lockless. It's possible for another | |
1719 | * open to race in after we did the earlier check for a conflicting | |
1720 | * open but before the lease was inserted. Check again for a | |
1721 | * conflicting open and cancel the lease if there is one. | |
1722 | * | |
1723 | * We also add a barrier here to ensure that the insertion of the lock | |
1724 | * precedes these checks. | |
1725 | */ | |
1726 | smp_mb(); | |
387e3746 | 1727 | error = check_conflicting_open(filp, arg, lease->fl_flags); |
8634b51f | 1728 | if (error) { |
e084c1bd | 1729 | locks_unlink_lock_ctx(lease); |
8634b51f JL |
1730 | goto out; |
1731 | } | |
1c7dd2ff JL |
1732 | |
1733 | out_setup: | |
1734 | if (lease->fl_lmops->lm_setup) | |
1735 | lease->fl_lmops->lm_setup(lease, priv); | |
1da177e4 | 1736 | out: |
6109c850 | 1737 | spin_unlock(&ctx->flc_lock); |
02e525b2 | 1738 | percpu_up_read(&file_rwsem); |
c45198ed | 1739 | locks_dispose_list(&dispose); |
df4e8d2c | 1740 | if (is_deleg) |
5955102c | 1741 | inode_unlock(inode); |
8634b51f | 1742 | if (!error && !my_fl) |
1c7dd2ff | 1743 | *flp = NULL; |
1da177e4 LT |
1744 | return error; |
1745 | } | |
8335ebd9 | 1746 | |
2ab99ee1 | 1747 | static int generic_delete_lease(struct file *filp, void *owner) |
8335ebd9 | 1748 | { |
0efaa7e8 | 1749 | int error = -EAGAIN; |
8634b51f | 1750 | struct file_lock *fl, *victim = NULL; |
c568d683 | 1751 | struct inode *inode = locks_inode(filp); |
128a3785 | 1752 | struct file_lock_context *ctx; |
c45198ed | 1753 | LIST_HEAD(dispose); |
8335ebd9 | 1754 | |
128a3785 | 1755 | ctx = smp_load_acquire(&inode->i_flctx); |
8634b51f JL |
1756 | if (!ctx) { |
1757 | trace_generic_delete_lease(inode, NULL); | |
1758 | return error; | |
1759 | } | |
1760 | ||
02e525b2 | 1761 | percpu_down_read(&file_rwsem); |
6109c850 | 1762 | spin_lock(&ctx->flc_lock); |
8634b51f | 1763 | list_for_each_entry(fl, &ctx->flc_lease, fl_list) { |
2ab99ee1 CH |
1764 | if (fl->fl_file == filp && |
1765 | fl->fl_owner == owner) { | |
8634b51f | 1766 | victim = fl; |
0efaa7e8 | 1767 | break; |
8634b51f | 1768 | } |
8335ebd9 | 1769 | } |
a9b1b455 | 1770 | trace_generic_delete_lease(inode, victim); |
8634b51f | 1771 | if (victim) |
7448cc37 | 1772 | error = fl->fl_lmops->lm_change(victim, F_UNLCK, &dispose); |
6109c850 | 1773 | spin_unlock(&ctx->flc_lock); |
02e525b2 | 1774 | percpu_up_read(&file_rwsem); |
c45198ed | 1775 | locks_dispose_list(&dispose); |
0efaa7e8 | 1776 | return error; |
8335ebd9 BF |
1777 | } |
1778 | ||
1779 | /** | |
1780 | * generic_setlease - sets a lease on an open file | |
1c7dd2ff JL |
1781 | * @filp: file pointer |
1782 | * @arg: type of lease to obtain | |
1783 | * @flp: input - file_lock to use, output - file_lock inserted | |
1784 | * @priv: private data for lm_setup (may be NULL if lm_setup | |
1785 | * doesn't require it) | |
8335ebd9 BF |
1786 | * |
1787 | * The (input) flp->fl_lmops->lm_break function is required | |
1788 | * by break_lease(). | |
8335ebd9 | 1789 | */ |
e6f5c789 JL |
1790 | int generic_setlease(struct file *filp, long arg, struct file_lock **flp, |
1791 | void **priv) | |
8335ebd9 | 1792 | { |
c568d683 | 1793 | struct inode *inode = locks_inode(filp); |
8335ebd9 BF |
1794 | int error; |
1795 | ||
8e96e3b7 | 1796 | if ((!uid_eq(current_fsuid(), inode->i_uid)) && !capable(CAP_LEASE)) |
8335ebd9 BF |
1797 | return -EACCES; |
1798 | if (!S_ISREG(inode->i_mode)) | |
1799 | return -EINVAL; | |
1800 | error = security_file_lock(filp, arg); | |
1801 | if (error) | |
1802 | return error; | |
1803 | ||
8335ebd9 BF |
1804 | switch (arg) { |
1805 | case F_UNLCK: | |
2ab99ee1 | 1806 | return generic_delete_lease(filp, *priv); |
8335ebd9 BF |
1807 | case F_RDLCK: |
1808 | case F_WRLCK: | |
0efaa7e8 JL |
1809 | if (!(*flp)->fl_lmops->lm_break) { |
1810 | WARN_ON_ONCE(1); | |
1811 | return -ENOLCK; | |
1812 | } | |
11afe9f7 | 1813 | |
e6f5c789 | 1814 | return generic_add_lease(filp, arg, flp, priv); |
8335ebd9 | 1815 | default: |
8d657eb3 | 1816 | return -EINVAL; |
8335ebd9 BF |
1817 | } |
1818 | } | |
0af1a450 | 1819 | EXPORT_SYMBOL(generic_setlease); |
1da177e4 | 1820 | |
18f6622e JL |
1821 | #if IS_ENABLED(CONFIG_SRCU) |
1822 | /* | |
1823 | * Kernel subsystems can register to be notified on any attempt to set | |
1824 | * a new lease with the lease_notifier_chain. This is used by (e.g.) nfsd | |
1825 | * to close files that it may have cached when there is an attempt to set a | |
1826 | * conflicting lease. | |
1827 | */ | |
1828 | static struct srcu_notifier_head lease_notifier_chain; | |
1829 | ||
1830 | static inline void | |
1831 | lease_notifier_chain_init(void) | |
1832 | { | |
1833 | srcu_init_notifier_head(&lease_notifier_chain); | |
1834 | } | |
1835 | ||
1836 | static inline void | |
1837 | setlease_notifier(long arg, struct file_lock *lease) | |
1838 | { | |
1839 | if (arg != F_UNLCK) | |
1840 | srcu_notifier_call_chain(&lease_notifier_chain, arg, lease); | |
1841 | } | |
1842 | ||
1843 | int lease_register_notifier(struct notifier_block *nb) | |
1844 | { | |
1845 | return srcu_notifier_chain_register(&lease_notifier_chain, nb); | |
1846 | } | |
1847 | EXPORT_SYMBOL_GPL(lease_register_notifier); | |
1848 | ||
1849 | void lease_unregister_notifier(struct notifier_block *nb) | |
1850 | { | |
1851 | srcu_notifier_chain_unregister(&lease_notifier_chain, nb); | |
1852 | } | |
1853 | EXPORT_SYMBOL_GPL(lease_unregister_notifier); | |
1854 | ||
1855 | #else /* !IS_ENABLED(CONFIG_SRCU) */ | |
1856 | static inline void | |
1857 | lease_notifier_chain_init(void) | |
1858 | { | |
1859 | } | |
1860 | ||
1861 | static inline void | |
1862 | setlease_notifier(long arg, struct file_lock *lease) | |
1863 | { | |
1864 | } | |
1865 | ||
1866 | int lease_register_notifier(struct notifier_block *nb) | |
1867 | { | |
1868 | return 0; | |
1869 | } | |
1870 | EXPORT_SYMBOL_GPL(lease_register_notifier); | |
1871 | ||
1872 | void lease_unregister_notifier(struct notifier_block *nb) | |
1873 | { | |
1874 | } | |
1875 | EXPORT_SYMBOL_GPL(lease_unregister_notifier); | |
1876 | ||
1877 | #endif /* IS_ENABLED(CONFIG_SRCU) */ | |
1878 | ||
b89f4321 | 1879 | /** |
e51673aa | 1880 | * vfs_setlease - sets a lease on an open file |
1c7dd2ff JL |
1881 | * @filp: file pointer |
1882 | * @arg: type of lease to obtain | |
1883 | * @lease: file_lock to use when adding a lease | |
1884 | * @priv: private info for lm_setup when adding a lease (may be | |
7bbd1fc0 | 1885 | * NULL if lm_setup doesn't require it) |
e51673aa JL |
1886 | * |
1887 | * Call this to establish a lease on the file. The "lease" argument is not | |
1888 | * used for F_UNLCK requests and may be NULL. For commands that set or alter | |
80b79dd0 MCC |
1889 | * an existing lease, the ``(*lease)->fl_lmops->lm_break`` operation must be |
1890 | * set; if not, this function will return -ENOLCK (and generate a scary-looking | |
e51673aa | 1891 | * stack trace). |
1c7dd2ff JL |
1892 | * |
1893 | * The "priv" pointer is passed directly to the lm_setup function as-is. It | |
1894 | * may be NULL if the lm_setup operation doesn't require it. | |
1da177e4 | 1895 | */ |
e6f5c789 JL |
1896 | int |
1897 | vfs_setlease(struct file *filp, long arg, struct file_lock **lease, void **priv) | |
1da177e4 | 1898 | { |
18f6622e JL |
1899 | if (lease) |
1900 | setlease_notifier(arg, *lease); | |
de2a4a50 | 1901 | if (filp->f_op->setlease) |
f82b4b67 | 1902 | return filp->f_op->setlease(filp, arg, lease, priv); |
1c7dd2ff | 1903 | else |
f82b4b67 | 1904 | return generic_setlease(filp, arg, lease, priv); |
1da177e4 | 1905 | } |
a9933cea | 1906 | EXPORT_SYMBOL_GPL(vfs_setlease); |
1da177e4 | 1907 | |
0ceaf6c7 | 1908 | static int do_fcntl_add_lease(unsigned int fd, struct file *filp, long arg) |
1da177e4 | 1909 | { |
1c7dd2ff | 1910 | struct file_lock *fl; |
f7347ce4 | 1911 | struct fasync_struct *new; |
1da177e4 LT |
1912 | int error; |
1913 | ||
c5b1f0d9 AB |
1914 | fl = lease_alloc(filp, arg); |
1915 | if (IS_ERR(fl)) | |
1916 | return PTR_ERR(fl); | |
1da177e4 | 1917 | |
f7347ce4 LT |
1918 | new = fasync_alloc(); |
1919 | if (!new) { | |
1920 | locks_free_lock(fl); | |
1921 | return -ENOMEM; | |
1922 | } | |
1c7dd2ff | 1923 | new->fa_fd = fd; |
f7347ce4 | 1924 | |
1c7dd2ff | 1925 | error = vfs_setlease(filp, arg, &fl, (void **)&new); |
2dfb928f JL |
1926 | if (fl) |
1927 | locks_free_lock(fl); | |
f7347ce4 LT |
1928 | if (new) |
1929 | fasync_free(new); | |
1da177e4 LT |
1930 | return error; |
1931 | } | |
1932 | ||
0ceaf6c7 BF |
1933 | /** |
1934 | * fcntl_setlease - sets a lease on an open file | |
1935 | * @fd: open file descriptor | |
1936 | * @filp: file pointer | |
1937 | * @arg: type of lease to obtain | |
1938 | * | |
1939 | * Call this fcntl to establish a lease on the file. | |
1940 | * Note that you also need to call %F_SETSIG to | |
1941 | * receive a signal when the lease is broken. | |
1942 | */ | |
1943 | int fcntl_setlease(unsigned int fd, struct file *filp, long arg) | |
1944 | { | |
1945 | if (arg == F_UNLCK) | |
2ab99ee1 | 1946 | return vfs_setlease(filp, F_UNLCK, NULL, (void **)&filp); |
0ceaf6c7 BF |
1947 | return do_fcntl_add_lease(fd, filp, arg); |
1948 | } | |
1949 | ||
1da177e4 | 1950 | /** |
29d01b22 JL |
1951 | * flock_lock_inode_wait - Apply a FLOCK-style lock to a file |
1952 | * @inode: inode of the file to apply to | |
1da177e4 LT |
1953 | * @fl: The lock to be applied |
1954 | * | |
29d01b22 | 1955 | * Apply a FLOCK style lock request to an inode. |
1da177e4 | 1956 | */ |
616fb38f | 1957 | static int flock_lock_inode_wait(struct inode *inode, struct file_lock *fl) |
1da177e4 LT |
1958 | { |
1959 | int error; | |
1960 | might_sleep(); | |
1961 | for (;;) { | |
29d01b22 | 1962 | error = flock_lock_inode(inode, fl); |
bde74e4b | 1963 | if (error != FILE_LOCK_DEFERRED) |
1da177e4 | 1964 | break; |
dcf23ac3 LT |
1965 | error = wait_event_interruptible(fl->fl_wait, |
1966 | list_empty(&fl->fl_blocked_member)); | |
16306a61 N |
1967 | if (error) |
1968 | break; | |
1da177e4 | 1969 | } |
16306a61 | 1970 | locks_delete_block(fl); |
1da177e4 LT |
1971 | return error; |
1972 | } | |
1973 | ||
e55c34a6 BC |
1974 | /** |
1975 | * locks_lock_inode_wait - Apply a lock to an inode | |
1976 | * @inode: inode of the file to apply to | |
1977 | * @fl: The lock to be applied | |
1978 | * | |
1979 | * Apply a POSIX or FLOCK style lock request to an inode. | |
1980 | */ | |
1981 | int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl) | |
1982 | { | |
1983 | int res = 0; | |
1984 | switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { | |
1985 | case FL_POSIX: | |
1986 | res = posix_lock_inode_wait(inode, fl); | |
1987 | break; | |
1988 | case FL_FLOCK: | |
1989 | res = flock_lock_inode_wait(inode, fl); | |
1990 | break; | |
1991 | default: | |
1992 | BUG(); | |
1993 | } | |
1994 | return res; | |
1995 | } | |
1996 | EXPORT_SYMBOL(locks_lock_inode_wait); | |
1997 | ||
1da177e4 LT |
1998 | /** |
1999 | * sys_flock: - flock() system call. | |
2000 | * @fd: the file descriptor to lock. | |
2001 | * @cmd: the type of lock to apply. | |
2002 | * | |
2003 | * Apply a %FL_FLOCK style lock to an open file descriptor. | |
80b79dd0 | 2004 | * The @cmd can be one of: |
1da177e4 | 2005 | * |
80b79dd0 MCC |
2006 | * - %LOCK_SH -- a shared lock. |
2007 | * - %LOCK_EX -- an exclusive lock. | |
2008 | * - %LOCK_UN -- remove an existing lock. | |
90f7d7a0 | 2009 | * - %LOCK_MAND -- a 'mandatory' flock. (DEPRECATED) |
1da177e4 | 2010 | * |
90f7d7a0 | 2011 | * %LOCK_MAND support has been removed from the kernel. |
1da177e4 | 2012 | */ |
002c8976 | 2013 | SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) |
1da177e4 | 2014 | { |
2903ff01 | 2015 | struct fd f = fdget(fd); |
1da177e4 LT |
2016 | struct file_lock *lock; |
2017 | int can_sleep, unlock; | |
2018 | int error; | |
2019 | ||
2020 | error = -EBADF; | |
2903ff01 | 2021 | if (!f.file) |
1da177e4 LT |
2022 | goto out; |
2023 | ||
2024 | can_sleep = !(cmd & LOCK_NB); | |
2025 | cmd &= ~LOCK_NB; | |
2026 | unlock = (cmd == LOCK_UN); | |
2027 | ||
90f7d7a0 JL |
2028 | if (!unlock && !(f.file->f_mode & (FMODE_READ|FMODE_WRITE))) |
2029 | goto out_putf; | |
2030 | ||
2031 | /* | |
2032 | * LOCK_MAND locks were broken for a long time in that they never | |
2033 | * conflicted with one another and didn't prevent any sort of open, | |
2034 | * read or write activity. | |
2035 | * | |
2036 | * Just ignore these requests now, to preserve legacy behavior, but | |
2037 | * throw a warning to let people know that they don't actually work. | |
2038 | */ | |
2039 | if (cmd & LOCK_MAND) { | |
2040 | pr_warn_once("Attempt to set a LOCK_MAND lock via flock(2). This support has been removed and the request ignored.\n"); | |
2041 | error = 0; | |
1da177e4 | 2042 | goto out_putf; |
90f7d7a0 | 2043 | } |
1da177e4 | 2044 | |
d6367d62 | 2045 | lock = flock_make_lock(f.file, cmd, NULL); |
6e129d00 JL |
2046 | if (IS_ERR(lock)) { |
2047 | error = PTR_ERR(lock); | |
1da177e4 | 2048 | goto out_putf; |
6e129d00 JL |
2049 | } |
2050 | ||
1da177e4 LT |
2051 | if (can_sleep) |
2052 | lock->fl_flags |= FL_SLEEP; | |
2053 | ||
2903ff01 | 2054 | error = security_file_lock(f.file, lock->fl_type); |
1da177e4 LT |
2055 | if (error) |
2056 | goto out_free; | |
2057 | ||
de2a4a50 | 2058 | if (f.file->f_op->flock) |
2903ff01 | 2059 | error = f.file->f_op->flock(f.file, |
1da177e4 LT |
2060 | (can_sleep) ? F_SETLKW : F_SETLK, |
2061 | lock); | |
2062 | else | |
4f656367 | 2063 | error = locks_lock_file_wait(f.file, lock); |
1da177e4 LT |
2064 | |
2065 | out_free: | |
993dfa87 | 2066 | locks_free_lock(lock); |
1da177e4 LT |
2067 | |
2068 | out_putf: | |
2903ff01 | 2069 | fdput(f); |
1da177e4 LT |
2070 | out: |
2071 | return error; | |
2072 | } | |
2073 | ||
3ee17abd BF |
2074 | /** |
2075 | * vfs_test_lock - test file byte range lock | |
2076 | * @filp: The file to test lock for | |
6924c554 | 2077 | * @fl: The lock to test; also used to hold result |
3ee17abd BF |
2078 | * |
2079 | * Returns -ERRNO on failure. Indicates presence of conflicting lock by | |
2080 | * setting conf->fl_type to something other than F_UNLCK. | |
2081 | */ | |
2082 | int vfs_test_lock(struct file *filp, struct file_lock *fl) | |
2083 | { | |
de2a4a50 | 2084 | if (filp->f_op->lock) |
3ee17abd BF |
2085 | return filp->f_op->lock(filp, F_GETLK, fl); |
2086 | posix_test_lock(filp, fl); | |
2087 | return 0; | |
2088 | } | |
2089 | EXPORT_SYMBOL_GPL(vfs_test_lock); | |
2090 | ||
9d5b86ac BC |
2091 | /** |
2092 | * locks_translate_pid - translate a file_lock's fl_pid number into a namespace | |
2093 | * @fl: The file_lock who's fl_pid should be translated | |
2094 | * @ns: The namespace into which the pid should be translated | |
2095 | * | |
2096 | * Used to tranlate a fl_pid into a namespace virtual pid number | |
2097 | */ | |
2098 | static pid_t locks_translate_pid(struct file_lock *fl, struct pid_namespace *ns) | |
2099 | { | |
2100 | pid_t vnr; | |
2101 | struct pid *pid; | |
2102 | ||
2103 | if (IS_OFDLCK(fl)) | |
2104 | return -1; | |
2105 | if (IS_REMOTELCK(fl)) | |
2106 | return fl->fl_pid; | |
826d7bc9 KK |
2107 | /* |
2108 | * If the flock owner process is dead and its pid has been already | |
2109 | * freed, the translation below won't work, but we still want to show | |
2110 | * flock owner pid number in init pidns. | |
2111 | */ | |
2112 | if (ns == &init_pid_ns) | |
2113 | return (pid_t)fl->fl_pid; | |
9d5b86ac BC |
2114 | |
2115 | rcu_read_lock(); | |
2116 | pid = find_pid_ns(fl->fl_pid, &init_pid_ns); | |
2117 | vnr = pid_nr_ns(pid, ns); | |
2118 | rcu_read_unlock(); | |
2119 | return vnr; | |
2120 | } | |
2121 | ||
c2fa1b8a BF |
2122 | static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl) |
2123 | { | |
9d5b86ac | 2124 | flock->l_pid = locks_translate_pid(fl, task_active_pid_ns(current)); |
c2fa1b8a BF |
2125 | #if BITS_PER_LONG == 32 |
2126 | /* | |
2127 | * Make sure we can represent the posix lock via | |
2128 | * legacy 32bit flock. | |
2129 | */ | |
2130 | if (fl->fl_start > OFFT_OFFSET_MAX) | |
2131 | return -EOVERFLOW; | |
2132 | if (fl->fl_end != OFFSET_MAX && fl->fl_end > OFFT_OFFSET_MAX) | |
2133 | return -EOVERFLOW; | |
2134 | #endif | |
2135 | flock->l_start = fl->fl_start; | |
2136 | flock->l_len = fl->fl_end == OFFSET_MAX ? 0 : | |
2137 | fl->fl_end - fl->fl_start + 1; | |
2138 | flock->l_whence = 0; | |
129a84de | 2139 | flock->l_type = fl->fl_type; |
c2fa1b8a BF |
2140 | return 0; |
2141 | } | |
2142 | ||
2143 | #if BITS_PER_LONG == 32 | |
2144 | static void posix_lock_to_flock64(struct flock64 *flock, struct file_lock *fl) | |
2145 | { | |
9d5b86ac | 2146 | flock->l_pid = locks_translate_pid(fl, task_active_pid_ns(current)); |
c2fa1b8a BF |
2147 | flock->l_start = fl->fl_start; |
2148 | flock->l_len = fl->fl_end == OFFSET_MAX ? 0 : | |
2149 | fl->fl_end - fl->fl_start + 1; | |
2150 | flock->l_whence = 0; | |
2151 | flock->l_type = fl->fl_type; | |
2152 | } | |
2153 | #endif | |
2154 | ||
1da177e4 LT |
2155 | /* Report the first existing lock that would conflict with l. |
2156 | * This implements the F_GETLK command of fcntl(). | |
2157 | */ | |
a75d30c7 | 2158 | int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock *flock) |
1da177e4 | 2159 | { |
52306e88 | 2160 | struct file_lock *fl; |
1da177e4 LT |
2161 | int error; |
2162 | ||
52306e88 BC |
2163 | fl = locks_alloc_lock(); |
2164 | if (fl == NULL) | |
2165 | return -ENOMEM; | |
1da177e4 | 2166 | error = -EINVAL; |
a75d30c7 | 2167 | if (flock->l_type != F_RDLCK && flock->l_type != F_WRLCK) |
1da177e4 LT |
2168 | goto out; |
2169 | ||
52306e88 | 2170 | error = flock_to_posix_lock(filp, fl, flock); |
1da177e4 LT |
2171 | if (error) |
2172 | goto out; | |
2173 | ||
0d3f7a2d | 2174 | if (cmd == F_OFD_GETLK) { |
90478939 | 2175 | error = -EINVAL; |
a75d30c7 | 2176 | if (flock->l_pid != 0) |
90478939 JL |
2177 | goto out; |
2178 | ||
52306e88 BC |
2179 | fl->fl_flags |= FL_OFDLCK; |
2180 | fl->fl_owner = filp; | |
5d50ffd7 JL |
2181 | } |
2182 | ||
52306e88 | 2183 | error = vfs_test_lock(filp, fl); |
3ee17abd BF |
2184 | if (error) |
2185 | goto out; | |
7bbd1fc0 | 2186 | |
52306e88 BC |
2187 | flock->l_type = fl->fl_type; |
2188 | if (fl->fl_type != F_UNLCK) { | |
2189 | error = posix_lock_to_flock(flock, fl); | |
c2fa1b8a | 2190 | if (error) |
52306e88 | 2191 | goto out; |
1da177e4 | 2192 | } |
1da177e4 | 2193 | out: |
52306e88 | 2194 | locks_free_lock(fl); |
1da177e4 LT |
2195 | return error; |
2196 | } | |
2197 | ||
7723ec97 ME |
2198 | /** |
2199 | * vfs_lock_file - file byte range lock | |
2200 | * @filp: The file to apply the lock to | |
2201 | * @cmd: type of locking operation (F_SETLK, F_GETLK, etc.) | |
2202 | * @fl: The lock to be applied | |
150b3934 ME |
2203 | * @conf: Place to return a copy of the conflicting lock, if found. |
2204 | * | |
2205 | * A caller that doesn't care about the conflicting lock may pass NULL | |
2206 | * as the final argument. | |
2207 | * | |
2208 | * If the filesystem defines a private ->lock() method, then @conf will | |
2209 | * be left unchanged; so a caller that cares should initialize it to | |
2210 | * some acceptable default. | |
2beb6614 ME |
2211 | * |
2212 | * To avoid blocking kernel daemons, such as lockd, that need to acquire POSIX | |
2213 | * locks, the ->lock() interface may return asynchronously, before the lock has | |
2214 | * been granted or denied by the underlying filesystem, if (and only if) | |
8fb47a4f | 2215 | * lm_grant is set. Callers expecting ->lock() to return asynchronously |
2beb6614 ME |
2216 | * will only use F_SETLK, not F_SETLKW; they will set FL_SLEEP if (and only if) |
2217 | * the request is for a blocking lock. When ->lock() does return asynchronously, | |
8fb47a4f | 2218 | * it must return FILE_LOCK_DEFERRED, and call ->lm_grant() when the lock |
2beb6614 ME |
2219 | * request completes. |
2220 | * If the request is for non-blocking lock the file system should return | |
bde74e4b MS |
2221 | * FILE_LOCK_DEFERRED then try to get the lock and call the callback routine |
2222 | * with the result. If the request timed out the callback routine will return a | |
2beb6614 ME |
2223 | * nonzero return code and the file system should release the lock. The file |
2224 | * system is also responsible to keep a corresponding posix lock when it | |
2225 | * grants a lock so the VFS can find out which locks are locally held and do | |
2226 | * the correct lock cleanup when required. | |
2227 | * The underlying filesystem must not drop the kernel lock or call | |
8fb47a4f | 2228 | * ->lm_grant() before returning to the caller with a FILE_LOCK_DEFERRED |
2beb6614 | 2229 | * return code. |
7723ec97 | 2230 | */ |
150b3934 | 2231 | int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, struct file_lock *conf) |
7723ec97 | 2232 | { |
de2a4a50 | 2233 | if (filp->f_op->lock) |
7723ec97 ME |
2234 | return filp->f_op->lock(filp, cmd, fl); |
2235 | else | |
150b3934 | 2236 | return posix_lock_file(filp, fl, conf); |
7723ec97 ME |
2237 | } |
2238 | EXPORT_SYMBOL_GPL(vfs_lock_file); | |
2239 | ||
b648a6de MS |
2240 | static int do_lock_file_wait(struct file *filp, unsigned int cmd, |
2241 | struct file_lock *fl) | |
2242 | { | |
2243 | int error; | |
2244 | ||
2245 | error = security_file_lock(filp, fl->fl_type); | |
2246 | if (error) | |
2247 | return error; | |
2248 | ||
764c76b3 MS |
2249 | for (;;) { |
2250 | error = vfs_lock_file(filp, cmd, fl, NULL); | |
2251 | if (error != FILE_LOCK_DEFERRED) | |
b648a6de | 2252 | break; |
dcf23ac3 LT |
2253 | error = wait_event_interruptible(fl->fl_wait, |
2254 | list_empty(&fl->fl_blocked_member)); | |
16306a61 N |
2255 | if (error) |
2256 | break; | |
b648a6de | 2257 | } |
16306a61 | 2258 | locks_delete_block(fl); |
b648a6de MS |
2259 | |
2260 | return error; | |
2261 | } | |
2262 | ||
6ca7d910 | 2263 | /* Ensure that fl->fl_file has compatible f_mode for F_SETLK calls */ |
cf01f4ee JL |
2264 | static int |
2265 | check_fmode_for_setlk(struct file_lock *fl) | |
2266 | { | |
2267 | switch (fl->fl_type) { | |
2268 | case F_RDLCK: | |
2269 | if (!(fl->fl_file->f_mode & FMODE_READ)) | |
2270 | return -EBADF; | |
2271 | break; | |
2272 | case F_WRLCK: | |
2273 | if (!(fl->fl_file->f_mode & FMODE_WRITE)) | |
2274 | return -EBADF; | |
2275 | } | |
2276 | return 0; | |
2277 | } | |
2278 | ||
1da177e4 LT |
2279 | /* Apply the lock described by l to an open file descriptor. |
2280 | * This implements both the F_SETLK and F_SETLKW commands of fcntl(). | |
2281 | */ | |
c293621b | 2282 | int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, |
a75d30c7 | 2283 | struct flock *flock) |
1da177e4 LT |
2284 | { |
2285 | struct file_lock *file_lock = locks_alloc_lock(); | |
a75d30c7 | 2286 | struct inode *inode = locks_inode(filp); |
0b2bac2f | 2287 | struct file *f; |
1da177e4 LT |
2288 | int error; |
2289 | ||
2290 | if (file_lock == NULL) | |
2291 | return -ENOLCK; | |
2292 | ||
a75d30c7 | 2293 | error = flock_to_posix_lock(filp, file_lock, flock); |
1da177e4 LT |
2294 | if (error) |
2295 | goto out; | |
5d50ffd7 | 2296 | |
cf01f4ee JL |
2297 | error = check_fmode_for_setlk(file_lock); |
2298 | if (error) | |
2299 | goto out; | |
2300 | ||
5d50ffd7 JL |
2301 | /* |
2302 | * If the cmd is requesting file-private locks, then set the | |
cff2fce5 | 2303 | * FL_OFDLCK flag and override the owner. |
5d50ffd7 JL |
2304 | */ |
2305 | switch (cmd) { | |
0d3f7a2d | 2306 | case F_OFD_SETLK: |
90478939 | 2307 | error = -EINVAL; |
a75d30c7 | 2308 | if (flock->l_pid != 0) |
90478939 JL |
2309 | goto out; |
2310 | ||
5d50ffd7 | 2311 | cmd = F_SETLK; |
cff2fce5 | 2312 | file_lock->fl_flags |= FL_OFDLCK; |
73a8f5f7 | 2313 | file_lock->fl_owner = filp; |
5d50ffd7 | 2314 | break; |
0d3f7a2d | 2315 | case F_OFD_SETLKW: |
90478939 | 2316 | error = -EINVAL; |
a75d30c7 | 2317 | if (flock->l_pid != 0) |
90478939 JL |
2318 | goto out; |
2319 | ||
5d50ffd7 | 2320 | cmd = F_SETLKW; |
cff2fce5 | 2321 | file_lock->fl_flags |= FL_OFDLCK; |
73a8f5f7 | 2322 | file_lock->fl_owner = filp; |
df561f66 | 2323 | fallthrough; |
5d50ffd7 | 2324 | case F_SETLKW: |
1da177e4 LT |
2325 | file_lock->fl_flags |= FL_SLEEP; |
2326 | } | |
5d50ffd7 | 2327 | |
b648a6de | 2328 | error = do_lock_file_wait(filp, cmd, file_lock); |
1da177e4 | 2329 | |
c293621b | 2330 | /* |
0752ba80 JL |
2331 | * Attempt to detect a close/fcntl race and recover by releasing the |
2332 | * lock that was just acquired. There is no need to do that when we're | |
2333 | * unlocking though, or for OFD locks. | |
c293621b | 2334 | */ |
0752ba80 JL |
2335 | if (!error && file_lock->fl_type != F_UNLCK && |
2336 | !(file_lock->fl_flags & FL_OFDLCK)) { | |
120ce2b0 | 2337 | struct files_struct *files = current->files; |
7f3697e2 JL |
2338 | /* |
2339 | * We need that spin_lock here - it prevents reordering between | |
2340 | * update of i_flctx->flc_posix and check for it done in | |
2341 | * close(). rcu_read_lock() wouldn't do. | |
2342 | */ | |
120ce2b0 EB |
2343 | spin_lock(&files->file_lock); |
2344 | f = files_lookup_fd_locked(files, fd); | |
2345 | spin_unlock(&files->file_lock); | |
7f3697e2 JL |
2346 | if (f != filp) { |
2347 | file_lock->fl_type = F_UNLCK; | |
2348 | error = do_lock_file_wait(filp, cmd, file_lock); | |
2349 | WARN_ON_ONCE(error); | |
2350 | error = -EBADF; | |
2351 | } | |
1da177e4 | 2352 | } |
c293621b | 2353 | out: |
1890910f | 2354 | trace_fcntl_setlk(inode, file_lock, error); |
1da177e4 LT |
2355 | locks_free_lock(file_lock); |
2356 | return error; | |
2357 | } | |
2358 | ||
2359 | #if BITS_PER_LONG == 32 | |
2360 | /* Report the first existing lock that would conflict with l. | |
2361 | * This implements the F_GETLK command of fcntl(). | |
2362 | */ | |
a75d30c7 | 2363 | int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 *flock) |
1da177e4 | 2364 | { |
52306e88 | 2365 | struct file_lock *fl; |
1da177e4 LT |
2366 | int error; |
2367 | ||
52306e88 BC |
2368 | fl = locks_alloc_lock(); |
2369 | if (fl == NULL) | |
2370 | return -ENOMEM; | |
2371 | ||
1da177e4 | 2372 | error = -EINVAL; |
a75d30c7 | 2373 | if (flock->l_type != F_RDLCK && flock->l_type != F_WRLCK) |
1da177e4 LT |
2374 | goto out; |
2375 | ||
52306e88 | 2376 | error = flock64_to_posix_lock(filp, fl, flock); |
1da177e4 LT |
2377 | if (error) |
2378 | goto out; | |
2379 | ||
0d3f7a2d | 2380 | if (cmd == F_OFD_GETLK) { |
90478939 | 2381 | error = -EINVAL; |
a75d30c7 | 2382 | if (flock->l_pid != 0) |
90478939 JL |
2383 | goto out; |
2384 | ||
5d50ffd7 | 2385 | cmd = F_GETLK64; |
52306e88 BC |
2386 | fl->fl_flags |= FL_OFDLCK; |
2387 | fl->fl_owner = filp; | |
5d50ffd7 JL |
2388 | } |
2389 | ||
52306e88 | 2390 | error = vfs_test_lock(filp, fl); |
3ee17abd BF |
2391 | if (error) |
2392 | goto out; | |
2393 | ||
52306e88 BC |
2394 | flock->l_type = fl->fl_type; |
2395 | if (fl->fl_type != F_UNLCK) | |
2396 | posix_lock_to_flock64(flock, fl); | |
f328296e | 2397 | |
1da177e4 | 2398 | out: |
52306e88 | 2399 | locks_free_lock(fl); |
1da177e4 LT |
2400 | return error; |
2401 | } | |
2402 | ||
2403 | /* Apply the lock described by l to an open file descriptor. | |
2404 | * This implements both the F_SETLK and F_SETLKW commands of fcntl(). | |
2405 | */ | |
c293621b | 2406 | int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd, |
a75d30c7 | 2407 | struct flock64 *flock) |
1da177e4 LT |
2408 | { |
2409 | struct file_lock *file_lock = locks_alloc_lock(); | |
0b2bac2f | 2410 | struct file *f; |
1da177e4 LT |
2411 | int error; |
2412 | ||
2413 | if (file_lock == NULL) | |
2414 | return -ENOLCK; | |
2415 | ||
a75d30c7 | 2416 | error = flock64_to_posix_lock(filp, file_lock, flock); |
1da177e4 LT |
2417 | if (error) |
2418 | goto out; | |
5d50ffd7 | 2419 | |
cf01f4ee JL |
2420 | error = check_fmode_for_setlk(file_lock); |
2421 | if (error) | |
2422 | goto out; | |
2423 | ||
5d50ffd7 JL |
2424 | /* |
2425 | * If the cmd is requesting file-private locks, then set the | |
cff2fce5 | 2426 | * FL_OFDLCK flag and override the owner. |
5d50ffd7 JL |
2427 | */ |
2428 | switch (cmd) { | |
0d3f7a2d | 2429 | case F_OFD_SETLK: |
90478939 | 2430 | error = -EINVAL; |
a75d30c7 | 2431 | if (flock->l_pid != 0) |
90478939 JL |
2432 | goto out; |
2433 | ||
5d50ffd7 | 2434 | cmd = F_SETLK64; |
cff2fce5 | 2435 | file_lock->fl_flags |= FL_OFDLCK; |
73a8f5f7 | 2436 | file_lock->fl_owner = filp; |
5d50ffd7 | 2437 | break; |
0d3f7a2d | 2438 | case F_OFD_SETLKW: |
90478939 | 2439 | error = -EINVAL; |
a75d30c7 | 2440 | if (flock->l_pid != 0) |
90478939 JL |
2441 | goto out; |
2442 | ||
5d50ffd7 | 2443 | cmd = F_SETLKW64; |
cff2fce5 | 2444 | file_lock->fl_flags |= FL_OFDLCK; |
73a8f5f7 | 2445 | file_lock->fl_owner = filp; |
df561f66 | 2446 | fallthrough; |
5d50ffd7 | 2447 | case F_SETLKW64: |
1da177e4 LT |
2448 | file_lock->fl_flags |= FL_SLEEP; |
2449 | } | |
5d50ffd7 | 2450 | |
b648a6de | 2451 | error = do_lock_file_wait(filp, cmd, file_lock); |
1da177e4 | 2452 | |
c293621b | 2453 | /* |
0752ba80 JL |
2454 | * Attempt to detect a close/fcntl race and recover by releasing the |
2455 | * lock that was just acquired. There is no need to do that when we're | |
2456 | * unlocking though, or for OFD locks. | |
c293621b | 2457 | */ |
0752ba80 JL |
2458 | if (!error && file_lock->fl_type != F_UNLCK && |
2459 | !(file_lock->fl_flags & FL_OFDLCK)) { | |
120ce2b0 | 2460 | struct files_struct *files = current->files; |
7f3697e2 JL |
2461 | /* |
2462 | * We need that spin_lock here - it prevents reordering between | |
2463 | * update of i_flctx->flc_posix and check for it done in | |
2464 | * close(). rcu_read_lock() wouldn't do. | |
2465 | */ | |
120ce2b0 EB |
2466 | spin_lock(&files->file_lock); |
2467 | f = files_lookup_fd_locked(files, fd); | |
2468 | spin_unlock(&files->file_lock); | |
7f3697e2 JL |
2469 | if (f != filp) { |
2470 | file_lock->fl_type = F_UNLCK; | |
2471 | error = do_lock_file_wait(filp, cmd, file_lock); | |
2472 | WARN_ON_ONCE(error); | |
2473 | error = -EBADF; | |
2474 | } | |
1da177e4 | 2475 | } |
1da177e4 LT |
2476 | out: |
2477 | locks_free_lock(file_lock); | |
2478 | return error; | |
2479 | } | |
2480 | #endif /* BITS_PER_LONG == 32 */ | |
2481 | ||
2482 | /* | |
2483 | * This function is called when the file is being removed | |
2484 | * from the task's fd array. POSIX locks belonging to this task | |
2485 | * are deleted at this time. | |
2486 | */ | |
2487 | void locks_remove_posix(struct file *filp, fl_owner_t owner) | |
2488 | { | |
1890910f | 2489 | int error; |
c568d683 | 2490 | struct inode *inode = locks_inode(filp); |
ff7b86b8 | 2491 | struct file_lock lock; |
128a3785 | 2492 | struct file_lock_context *ctx; |
1da177e4 LT |
2493 | |
2494 | /* | |
2495 | * If there are no locks held on this file, we don't need to call | |
2496 | * posix_lock_file(). Another process could be setting a lock on this | |
2497 | * file at the same time, but we wouldn't remove that lock anyway. | |
2498 | */ | |
c568d683 | 2499 | ctx = smp_load_acquire(&inode->i_flctx); |
bd61e0a9 | 2500 | if (!ctx || list_empty(&ctx->flc_posix)) |
1da177e4 LT |
2501 | return; |
2502 | ||
d6367d62 | 2503 | locks_init_lock(&lock); |
1da177e4 | 2504 | lock.fl_type = F_UNLCK; |
75e1fcc0 | 2505 | lock.fl_flags = FL_POSIX | FL_CLOSE; |
1da177e4 LT |
2506 | lock.fl_start = 0; |
2507 | lock.fl_end = OFFSET_MAX; | |
2508 | lock.fl_owner = owner; | |
2509 | lock.fl_pid = current->tgid; | |
2510 | lock.fl_file = filp; | |
2511 | lock.fl_ops = NULL; | |
2512 | lock.fl_lmops = NULL; | |
2513 | ||
1890910f | 2514 | error = vfs_lock_file(filp, F_SETLK, &lock, NULL); |
1da177e4 | 2515 | |
1da177e4 LT |
2516 | if (lock.fl_ops && lock.fl_ops->fl_release_private) |
2517 | lock.fl_ops->fl_release_private(&lock); | |
c568d683 | 2518 | trace_locks_remove_posix(inode, &lock, error); |
1da177e4 | 2519 | } |
1da177e4 LT |
2520 | EXPORT_SYMBOL(locks_remove_posix); |
2521 | ||
3d8e560d | 2522 | /* The i_flctx must be valid when calling into here */ |
dd459bb1 | 2523 | static void |
128a3785 | 2524 | locks_remove_flock(struct file *filp, struct file_lock_context *flctx) |
dd459bb1 | 2525 | { |
d6367d62 | 2526 | struct file_lock fl; |
c568d683 | 2527 | struct inode *inode = locks_inode(filp); |
dd459bb1 | 2528 | |
3d8e560d | 2529 | if (list_empty(&flctx->flc_flock)) |
dd459bb1 JL |
2530 | return; |
2531 | ||
d6367d62 N |
2532 | flock_make_lock(filp, LOCK_UN, &fl); |
2533 | fl.fl_flags |= FL_CLOSE; | |
2534 | ||
de2a4a50 | 2535 | if (filp->f_op->flock) |
dd459bb1 JL |
2536 | filp->f_op->flock(filp, F_SETLKW, &fl); |
2537 | else | |
bcd7f78d | 2538 | flock_lock_inode(inode, &fl); |
dd459bb1 JL |
2539 | |
2540 | if (fl.fl_ops && fl.fl_ops->fl_release_private) | |
2541 | fl.fl_ops->fl_release_private(&fl); | |
2542 | } | |
2543 | ||
3d8e560d | 2544 | /* The i_flctx must be valid when calling into here */ |
8634b51f | 2545 | static void |
128a3785 | 2546 | locks_remove_lease(struct file *filp, struct file_lock_context *ctx) |
8634b51f | 2547 | { |
8634b51f JL |
2548 | struct file_lock *fl, *tmp; |
2549 | LIST_HEAD(dispose); | |
2550 | ||
3d8e560d | 2551 | if (list_empty(&ctx->flc_lease)) |
8634b51f JL |
2552 | return; |
2553 | ||
02e525b2 | 2554 | percpu_down_read(&file_rwsem); |
6109c850 | 2555 | spin_lock(&ctx->flc_lock); |
8634b51f | 2556 | list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list) |
c4e136cd JL |
2557 | if (filp == fl->fl_file) |
2558 | lease_modify(fl, F_UNLCK, &dispose); | |
6109c850 | 2559 | spin_unlock(&ctx->flc_lock); |
02e525b2 | 2560 | percpu_up_read(&file_rwsem); |
5f43086b | 2561 | |
8634b51f JL |
2562 | locks_dispose_list(&dispose); |
2563 | } | |
2564 | ||
1da177e4 LT |
2565 | /* |
2566 | * This function is called on the last close of an open file. | |
2567 | */ | |
78ed8a13 | 2568 | void locks_remove_file(struct file *filp) |
1da177e4 | 2569 | { |
128a3785 DV |
2570 | struct file_lock_context *ctx; |
2571 | ||
c568d683 | 2572 | ctx = smp_load_acquire(&locks_inode(filp)->i_flctx); |
128a3785 | 2573 | if (!ctx) |
3d8e560d JL |
2574 | return; |
2575 | ||
dd459bb1 | 2576 | /* remove any OFD locks */ |
73a8f5f7 | 2577 | locks_remove_posix(filp, filp); |
5d50ffd7 | 2578 | |
dd459bb1 | 2579 | /* remove flock locks */ |
128a3785 | 2580 | locks_remove_flock(filp, ctx); |
dd459bb1 | 2581 | |
8634b51f | 2582 | /* remove any leases */ |
128a3785 | 2583 | locks_remove_lease(filp, ctx); |
3953704f BC |
2584 | |
2585 | spin_lock(&ctx->flc_lock); | |
2586 | locks_check_ctx_file_list(filp, &ctx->flc_posix, "POSIX"); | |
2587 | locks_check_ctx_file_list(filp, &ctx->flc_flock, "FLOCK"); | |
2588 | locks_check_ctx_file_list(filp, &ctx->flc_lease, "LEASE"); | |
2589 | spin_unlock(&ctx->flc_lock); | |
1da177e4 LT |
2590 | } |
2591 | ||
9b9d2ab4 ME |
2592 | /** |
2593 | * vfs_cancel_lock - file byte range unblock lock | |
2594 | * @filp: The file to apply the unblock to | |
2595 | * @fl: The lock to be unblocked | |
2596 | * | |
2597 | * Used by lock managers to cancel blocked requests | |
2598 | */ | |
2599 | int vfs_cancel_lock(struct file *filp, struct file_lock *fl) | |
2600 | { | |
de2a4a50 | 2601 | if (filp->f_op->lock) |
9b9d2ab4 ME |
2602 | return filp->f_op->lock(filp, F_CANCELLK, fl); |
2603 | return 0; | |
2604 | } | |
9b9d2ab4 ME |
2605 | EXPORT_SYMBOL_GPL(vfs_cancel_lock); |
2606 | ||
7f8ada98 | 2607 | #ifdef CONFIG_PROC_FS |
d8ba7a36 | 2608 | #include <linux/proc_fs.h> |
7f8ada98 PE |
2609 | #include <linux/seq_file.h> |
2610 | ||
7012b02a JL |
2611 | struct locks_iterator { |
2612 | int li_cpu; | |
2613 | loff_t li_pos; | |
2614 | }; | |
2615 | ||
7f8ada98 | 2616 | static void lock_get_status(struct seq_file *f, struct file_lock *fl, |
b8da9b10 | 2617 | loff_t id, char *pfx, int repeat) |
1da177e4 LT |
2618 | { |
2619 | struct inode *inode = NULL; | |
ab1f1611 | 2620 | unsigned int fl_pid; |
9d78edea | 2621 | struct pid_namespace *proc_pidns = proc_pid_ns(file_inode(f->file)->i_sb); |
90f7d7a0 | 2622 | int type; |
ab1f1611 | 2623 | |
9d5b86ac BC |
2624 | fl_pid = locks_translate_pid(fl, proc_pidns); |
2625 | /* | |
1cf8e5de KK |
2626 | * If lock owner is dead (and pid is freed) or not visible in current |
2627 | * pidns, zero is shown as a pid value. Check lock info from | |
2628 | * init_pid_ns to get saved lock pid value. | |
9d5b86ac | 2629 | */ |
1da177e4 LT |
2630 | |
2631 | if (fl->fl_file != NULL) | |
c568d683 | 2632 | inode = locks_inode(fl->fl_file); |
1da177e4 | 2633 | |
b8da9b10 LL |
2634 | seq_printf(f, "%lld: ", id); |
2635 | ||
2636 | if (repeat) | |
2637 | seq_printf(f, "%*s", repeat - 1 + (int)strlen(pfx), pfx); | |
2638 | ||
1da177e4 | 2639 | if (IS_POSIX(fl)) { |
c918d42a | 2640 | if (fl->fl_flags & FL_ACCESS) |
5315c26a | 2641 | seq_puts(f, "ACCESS"); |
cff2fce5 | 2642 | else if (IS_OFDLCK(fl)) |
5315c26a | 2643 | seq_puts(f, "OFDLCK"); |
c918d42a | 2644 | else |
5315c26a | 2645 | seq_puts(f, "POSIX "); |
c918d42a JL |
2646 | |
2647 | seq_printf(f, " %s ", | |
f7e33bdb | 2648 | (inode == NULL) ? "*NOINODE*" : "ADVISORY "); |
1da177e4 | 2649 | } else if (IS_FLOCK(fl)) { |
90f7d7a0 | 2650 | seq_puts(f, "FLOCK ADVISORY "); |
1da177e4 | 2651 | } else if (IS_LEASE(fl)) { |
8144f1f6 JL |
2652 | if (fl->fl_flags & FL_DELEG) |
2653 | seq_puts(f, "DELEG "); | |
2654 | else | |
2655 | seq_puts(f, "LEASE "); | |
2656 | ||
ab83fa4b | 2657 | if (lease_breaking(fl)) |
5315c26a | 2658 | seq_puts(f, "BREAKING "); |
1da177e4 | 2659 | else if (fl->fl_file) |
5315c26a | 2660 | seq_puts(f, "ACTIVE "); |
1da177e4 | 2661 | else |
5315c26a | 2662 | seq_puts(f, "BREAKER "); |
1da177e4 | 2663 | } else { |
5315c26a | 2664 | seq_puts(f, "UNKNOWN UNKNOWN "); |
1da177e4 | 2665 | } |
90f7d7a0 | 2666 | type = IS_LEASE(fl) ? target_leasetype(fl) : fl->fl_type; |
43e4cb94 | 2667 | |
90f7d7a0 JL |
2668 | seq_printf(f, "%s ", (type == F_WRLCK) ? "WRITE" : |
2669 | (type == F_RDLCK) ? "READ" : "UNLCK"); | |
1da177e4 | 2670 | if (inode) { |
3648888e | 2671 | /* userspace relies on this representation of dev_t */ |
98ca480a | 2672 | seq_printf(f, "%d %02x:%02x:%lu ", fl_pid, |
1da177e4 LT |
2673 | MAJOR(inode->i_sb->s_dev), |
2674 | MINOR(inode->i_sb->s_dev), inode->i_ino); | |
1da177e4 | 2675 | } else { |
ab1f1611 | 2676 | seq_printf(f, "%d <none>:0 ", fl_pid); |
1da177e4 LT |
2677 | } |
2678 | if (IS_POSIX(fl)) { | |
2679 | if (fl->fl_end == OFFSET_MAX) | |
7f8ada98 | 2680 | seq_printf(f, "%Ld EOF\n", fl->fl_start); |
1da177e4 | 2681 | else |
7f8ada98 | 2682 | seq_printf(f, "%Ld %Ld\n", fl->fl_start, fl->fl_end); |
1da177e4 | 2683 | } else { |
5315c26a | 2684 | seq_puts(f, "0 EOF\n"); |
1da177e4 LT |
2685 | } |
2686 | } | |
2687 | ||
b8da9b10 LL |
2688 | static struct file_lock *get_next_blocked_member(struct file_lock *node) |
2689 | { | |
2690 | struct file_lock *tmp; | |
2691 | ||
2692 | /* NULL node or root node */ | |
2693 | if (node == NULL || node->fl_blocker == NULL) | |
2694 | return NULL; | |
2695 | ||
2696 | /* Next member in the linked list could be itself */ | |
2697 | tmp = list_next_entry(node, fl_blocked_member); | |
2698 | if (list_entry_is_head(tmp, &node->fl_blocker->fl_blocked_requests, fl_blocked_member) | |
2699 | || tmp == node) { | |
2700 | return NULL; | |
2701 | } | |
2702 | ||
2703 | return tmp; | |
2704 | } | |
2705 | ||
7f8ada98 | 2706 | static int locks_show(struct seq_file *f, void *v) |
1da177e4 | 2707 | { |
7012b02a | 2708 | struct locks_iterator *iter = f->private; |
b8da9b10 | 2709 | struct file_lock *cur, *tmp; |
9d78edea | 2710 | struct pid_namespace *proc_pidns = proc_pid_ns(file_inode(f->file)->i_sb); |
b8da9b10 | 2711 | int level = 0; |
1da177e4 | 2712 | |
b8da9b10 | 2713 | cur = hlist_entry(v, struct file_lock, fl_link); |
1da177e4 | 2714 | |
b8da9b10 | 2715 | if (locks_translate_pid(cur, proc_pidns) == 0) |
d67fd44f NB |
2716 | return 0; |
2717 | ||
b8da9b10 LL |
2718 | /* View this crossed linked list as a binary tree, the first member of fl_blocked_requests |
2719 | * is the left child of current node, the next silibing in fl_blocked_member is the | |
2720 | * right child, we can alse get the parent of current node from fl_blocker, so this | |
2721 | * question becomes traversal of a binary tree | |
2722 | */ | |
2723 | while (cur != NULL) { | |
2724 | if (level) | |
2725 | lock_get_status(f, cur, iter->li_pos, "-> ", level); | |
2726 | else | |
2727 | lock_get_status(f, cur, iter->li_pos, "", level); | |
1da177e4 | 2728 | |
b8da9b10 LL |
2729 | if (!list_empty(&cur->fl_blocked_requests)) { |
2730 | /* Turn left */ | |
2731 | cur = list_first_entry_or_null(&cur->fl_blocked_requests, | |
2732 | struct file_lock, fl_blocked_member); | |
2733 | level++; | |
2734 | } else { | |
2735 | /* Turn right */ | |
2736 | tmp = get_next_blocked_member(cur); | |
2737 | /* Fall back to parent node */ | |
2738 | while (tmp == NULL && cur->fl_blocker != NULL) { | |
2739 | cur = cur->fl_blocker; | |
2740 | level--; | |
2741 | tmp = get_next_blocked_member(cur); | |
2742 | } | |
2743 | cur = tmp; | |
2744 | } | |
2745 | } | |
094f2825 | 2746 | |
7f8ada98 PE |
2747 | return 0; |
2748 | } | |
1da177e4 | 2749 | |
6c8c9031 AV |
2750 | static void __show_fd_locks(struct seq_file *f, |
2751 | struct list_head *head, int *id, | |
2752 | struct file *filp, struct files_struct *files) | |
2753 | { | |
2754 | struct file_lock *fl; | |
2755 | ||
2756 | list_for_each_entry(fl, head, fl_list) { | |
2757 | ||
2758 | if (filp != fl->fl_file) | |
2759 | continue; | |
2760 | if (fl->fl_owner != files && | |
2761 | fl->fl_owner != filp) | |
2762 | continue; | |
2763 | ||
2764 | (*id)++; | |
2765 | seq_puts(f, "lock:\t"); | |
b8da9b10 | 2766 | lock_get_status(f, fl, *id, "", 0); |
6c8c9031 AV |
2767 | } |
2768 | } | |
2769 | ||
2770 | void show_fd_locks(struct seq_file *f, | |
2771 | struct file *filp, struct files_struct *files) | |
2772 | { | |
c568d683 | 2773 | struct inode *inode = locks_inode(filp); |
6c8c9031 AV |
2774 | struct file_lock_context *ctx; |
2775 | int id = 0; | |
2776 | ||
128a3785 | 2777 | ctx = smp_load_acquire(&inode->i_flctx); |
6c8c9031 AV |
2778 | if (!ctx) |
2779 | return; | |
2780 | ||
2781 | spin_lock(&ctx->flc_lock); | |
2782 | __show_fd_locks(f, &ctx->flc_flock, &id, filp, files); | |
2783 | __show_fd_locks(f, &ctx->flc_posix, &id, filp, files); | |
2784 | __show_fd_locks(f, &ctx->flc_lease, &id, filp, files); | |
2785 | spin_unlock(&ctx->flc_lock); | |
2786 | } | |
2787 | ||
7f8ada98 | 2788 | static void *locks_start(struct seq_file *f, loff_t *pos) |
b03dfdec | 2789 | __acquires(&blocked_lock_lock) |
7f8ada98 | 2790 | { |
7012b02a | 2791 | struct locks_iterator *iter = f->private; |
99dc8292 | 2792 | |
7012b02a | 2793 | iter->li_pos = *pos + 1; |
aba37660 | 2794 | percpu_down_write(&file_rwsem); |
7b2296af | 2795 | spin_lock(&blocked_lock_lock); |
7c3f654d | 2796 | return seq_hlist_start_percpu(&file_lock_list.hlist, &iter->li_cpu, *pos); |
7f8ada98 | 2797 | } |
1da177e4 | 2798 | |
7f8ada98 PE |
2799 | static void *locks_next(struct seq_file *f, void *v, loff_t *pos) |
2800 | { | |
7012b02a JL |
2801 | struct locks_iterator *iter = f->private; |
2802 | ||
2803 | ++iter->li_pos; | |
7c3f654d | 2804 | return seq_hlist_next_percpu(v, &file_lock_list.hlist, &iter->li_cpu, pos); |
7f8ada98 | 2805 | } |
1da177e4 | 2806 | |
7f8ada98 | 2807 | static void locks_stop(struct seq_file *f, void *v) |
b03dfdec | 2808 | __releases(&blocked_lock_lock) |
7f8ada98 | 2809 | { |
7b2296af | 2810 | spin_unlock(&blocked_lock_lock); |
aba37660 | 2811 | percpu_up_write(&file_rwsem); |
1da177e4 LT |
2812 | } |
2813 | ||
d8ba7a36 | 2814 | static const struct seq_operations locks_seq_operations = { |
7f8ada98 PE |
2815 | .start = locks_start, |
2816 | .next = locks_next, | |
2817 | .stop = locks_stop, | |
2818 | .show = locks_show, | |
2819 | }; | |
d8ba7a36 | 2820 | |
d8ba7a36 AD |
2821 | static int __init proc_locks_init(void) |
2822 | { | |
44414d82 CH |
2823 | proc_create_seq_private("locks", 0, NULL, &locks_seq_operations, |
2824 | sizeof(struct locks_iterator), NULL); | |
d8ba7a36 AD |
2825 | return 0; |
2826 | } | |
91899226 | 2827 | fs_initcall(proc_locks_init); |
7f8ada98 PE |
2828 | #endif |
2829 | ||
1da177e4 LT |
2830 | static int __init filelock_init(void) |
2831 | { | |
7012b02a JL |
2832 | int i; |
2833 | ||
4a075e39 | 2834 | flctx_cache = kmem_cache_create("file_lock_ctx", |
3754707b | 2835 | sizeof(struct file_lock_context), 0, SLAB_PANIC, NULL); |
4a075e39 | 2836 | |
1da177e4 | 2837 | filelock_cache = kmem_cache_create("file_lock_cache", |
3754707b | 2838 | sizeof(struct file_lock), 0, SLAB_PANIC, NULL); |
ee19cc40 | 2839 | |
7c3f654d PZ |
2840 | for_each_possible_cpu(i) { |
2841 | struct file_lock_list_struct *fll = per_cpu_ptr(&file_lock_list, i); | |
2842 | ||
2843 | spin_lock_init(&fll->lock); | |
2844 | INIT_HLIST_HEAD(&fll->hlist); | |
2845 | } | |
7012b02a | 2846 | |
18f6622e | 2847 | lease_notifier_chain_init(); |
1da177e4 LT |
2848 | return 0; |
2849 | } | |
1da177e4 | 2850 | core_initcall(filelock_init); |