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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/fs/locks.c | |
3 | * | |
4 | * Provide support for fcntl()'s F_GETLK, F_SETLK, and F_SETLKW calls. | |
5 | * Doug Evans (dje@spiff.uucp), August 07, 1992 | |
6 | * | |
7 | * Deadlock detection added. | |
8 | * FIXME: one thing isn't handled yet: | |
9 | * - mandatory locks (requires lots of changes elsewhere) | |
10 | * Kelly Carmichael (kelly@[142.24.8.65]), September 17, 1994. | |
11 | * | |
12 | * Miscellaneous edits, and a total rewrite of posix_lock_file() code. | |
13 | * Kai Petzke (wpp@marie.physik.tu-berlin.de), 1994 | |
14 | * | |
15 | * Converted file_lock_table to a linked list from an array, which eliminates | |
16 | * the limits on how many active file locks are open. | |
17 | * Chad Page (pageone@netcom.com), November 27, 1994 | |
18 | * | |
19 | * Removed dependency on file descriptors. dup()'ed file descriptors now | |
20 | * get the same locks as the original file descriptors, and a close() on | |
21 | * any file descriptor removes ALL the locks on the file for the current | |
22 | * process. Since locks still depend on the process id, locks are inherited | |
23 | * after an exec() but not after a fork(). This agrees with POSIX, and both | |
24 | * BSD and SVR4 practice. | |
25 | * Andy Walker (andy@lysaker.kvaerner.no), February 14, 1995 | |
26 | * | |
27 | * Scrapped free list which is redundant now that we allocate locks | |
28 | * dynamically with kmalloc()/kfree(). | |
29 | * Andy Walker (andy@lysaker.kvaerner.no), February 21, 1995 | |
30 | * | |
31 | * Implemented two lock personalities - FL_FLOCK and FL_POSIX. | |
32 | * | |
33 | * FL_POSIX locks are created with calls to fcntl() and lockf() through the | |
34 | * fcntl() system call. They have the semantics described above. | |
35 | * | |
36 | * FL_FLOCK locks are created with calls to flock(), through the flock() | |
37 | * system call, which is new. Old C libraries implement flock() via fcntl() | |
38 | * and will continue to use the old, broken implementation. | |
39 | * | |
40 | * FL_FLOCK locks follow the 4.4 BSD flock() semantics. They are associated | |
41 | * with a file pointer (filp). As a result they can be shared by a parent | |
42 | * process and its children after a fork(). They are removed when the last | |
43 | * file descriptor referring to the file pointer is closed (unless explicitly | |
44 | * unlocked). | |
45 | * | |
46 | * FL_FLOCK locks never deadlock, an existing lock is always removed before | |
47 | * upgrading from shared to exclusive (or vice versa). When this happens | |
48 | * any processes blocked by the current lock are woken up and allowed to | |
49 | * run before the new lock is applied. | |
50 | * Andy Walker (andy@lysaker.kvaerner.no), June 09, 1995 | |
51 | * | |
52 | * Removed some race conditions in flock_lock_file(), marked other possible | |
53 | * races. Just grep for FIXME to see them. | |
54 | * Dmitry Gorodchanin (pgmdsg@ibi.com), February 09, 1996. | |
55 | * | |
56 | * Addressed Dmitry's concerns. Deadlock checking no longer recursive. | |
57 | * Lock allocation changed to GFP_ATOMIC as we can't afford to sleep | |
58 | * once we've checked for blocking and deadlocking. | |
59 | * Andy Walker (andy@lysaker.kvaerner.no), April 03, 1996. | |
60 | * | |
61 | * Initial implementation of mandatory locks. SunOS turned out to be | |
62 | * a rotten model, so I implemented the "obvious" semantics. | |
395cf969 | 63 | * See 'Documentation/filesystems/mandatory-locking.txt' for details. |
1da177e4 LT |
64 | * Andy Walker (andy@lysaker.kvaerner.no), April 06, 1996. |
65 | * | |
66 | * Don't allow mandatory locks on mmap()'ed files. Added simple functions to | |
67 | * check if a file has mandatory locks, used by mmap(), open() and creat() to | |
68 | * see if system call should be rejected. Ref. HP-UX/SunOS/Solaris Reference | |
69 | * Manual, Section 2. | |
70 | * Andy Walker (andy@lysaker.kvaerner.no), April 09, 1996. | |
71 | * | |
72 | * Tidied up block list handling. Added '/proc/locks' interface. | |
73 | * Andy Walker (andy@lysaker.kvaerner.no), April 24, 1996. | |
74 | * | |
75 | * Fixed deadlock condition for pathological code that mixes calls to | |
76 | * flock() and fcntl(). | |
77 | * Andy Walker (andy@lysaker.kvaerner.no), April 29, 1996. | |
78 | * | |
79 | * Allow only one type of locking scheme (FL_POSIX or FL_FLOCK) to be in use | |
80 | * for a given file at a time. Changed the CONFIG_LOCK_MANDATORY scheme to | |
81 | * guarantee sensible behaviour in the case where file system modules might | |
82 | * be compiled with different options than the kernel itself. | |
83 | * Andy Walker (andy@lysaker.kvaerner.no), May 15, 1996. | |
84 | * | |
85 | * Added a couple of missing wake_up() calls. Thanks to Thomas Meckel | |
86 | * (Thomas.Meckel@mni.fh-giessen.de) for spotting this. | |
87 | * Andy Walker (andy@lysaker.kvaerner.no), May 15, 1996. | |
88 | * | |
89 | * Changed FL_POSIX locks to use the block list in the same way as FL_FLOCK | |
90 | * locks. Changed process synchronisation to avoid dereferencing locks that | |
91 | * have already been freed. | |
92 | * Andy Walker (andy@lysaker.kvaerner.no), Sep 21, 1996. | |
93 | * | |
94 | * Made the block list a circular list to minimise searching in the list. | |
95 | * Andy Walker (andy@lysaker.kvaerner.no), Sep 25, 1996. | |
96 | * | |
97 | * Made mandatory locking a mount option. Default is not to allow mandatory | |
98 | * locking. | |
99 | * Andy Walker (andy@lysaker.kvaerner.no), Oct 04, 1996. | |
100 | * | |
101 | * Some adaptations for NFS support. | |
102 | * Olaf Kirch (okir@monad.swb.de), Dec 1996, | |
103 | * | |
104 | * Fixed /proc/locks interface so that we can't overrun the buffer we are handed. | |
105 | * Andy Walker (andy@lysaker.kvaerner.no), May 12, 1997. | |
106 | * | |
107 | * Use slab allocator instead of kmalloc/kfree. | |
108 | * Use generic list implementation from <linux/list.h>. | |
109 | * Sped up posix_locks_deadlock by only considering blocked locks. | |
110 | * Matthew Wilcox <willy@debian.org>, March, 2000. | |
111 | * | |
112 | * Leases and LOCK_MAND | |
113 | * Matthew Wilcox <willy@debian.org>, June, 2000. | |
114 | * Stephen Rothwell <sfr@canb.auug.org.au>, June, 2000. | |
115 | */ | |
116 | ||
117 | #include <linux/capability.h> | |
118 | #include <linux/file.h> | |
9f3acc31 | 119 | #include <linux/fdtable.h> |
1da177e4 LT |
120 | #include <linux/fs.h> |
121 | #include <linux/init.h> | |
1da177e4 LT |
122 | #include <linux/security.h> |
123 | #include <linux/slab.h> | |
1da177e4 LT |
124 | #include <linux/syscalls.h> |
125 | #include <linux/time.h> | |
4fb3a538 | 126 | #include <linux/rcupdate.h> |
ab1f1611 | 127 | #include <linux/pid_namespace.h> |
48f74186 | 128 | #include <linux/hashtable.h> |
7012b02a | 129 | #include <linux/percpu.h> |
1da177e4 | 130 | |
62af4f1f JL |
131 | #define CREATE_TRACE_POINTS |
132 | #include <trace/events/filelock.h> | |
133 | ||
7c0f6ba6 | 134 | #include <linux/uaccess.h> |
1da177e4 LT |
135 | |
136 | #define IS_POSIX(fl) (fl->fl_flags & FL_POSIX) | |
137 | #define IS_FLOCK(fl) (fl->fl_flags & FL_FLOCK) | |
11afe9f7 | 138 | #define IS_LEASE(fl) (fl->fl_flags & (FL_LEASE|FL_DELEG|FL_LAYOUT)) |
cff2fce5 | 139 | #define IS_OFDLCK(fl) (fl->fl_flags & FL_OFDLCK) |
9d5b86ac | 140 | #define IS_REMOTELCK(fl) (fl->fl_pid <= 0) |
1da177e4 | 141 | |
ab83fa4b BF |
142 | static bool lease_breaking(struct file_lock *fl) |
143 | { | |
778fc546 BF |
144 | return fl->fl_flags & (FL_UNLOCK_PENDING | FL_DOWNGRADE_PENDING); |
145 | } | |
146 | ||
147 | static int target_leasetype(struct file_lock *fl) | |
148 | { | |
149 | if (fl->fl_flags & FL_UNLOCK_PENDING) | |
150 | return F_UNLCK; | |
151 | if (fl->fl_flags & FL_DOWNGRADE_PENDING) | |
152 | return F_RDLCK; | |
153 | return fl->fl_type; | |
ab83fa4b BF |
154 | } |
155 | ||
1da177e4 LT |
156 | int leases_enable = 1; |
157 | int lease_break_time = 45; | |
158 | ||
1c8c601a | 159 | /* |
7012b02a | 160 | * The global file_lock_list is only used for displaying /proc/locks, so we |
7c3f654d PZ |
161 | * keep a list on each CPU, with each list protected by its own spinlock. |
162 | * Global serialization is done using file_rwsem. | |
163 | * | |
164 | * Note that alterations to the list also require that the relevant flc_lock is | |
165 | * held. | |
1c8c601a | 166 | */ |
7c3f654d PZ |
167 | struct file_lock_list_struct { |
168 | spinlock_t lock; | |
169 | struct hlist_head hlist; | |
170 | }; | |
171 | static DEFINE_PER_CPU(struct file_lock_list_struct, file_lock_list); | |
aba37660 | 172 | DEFINE_STATIC_PERCPU_RWSEM(file_rwsem); |
88974691 | 173 | |
1c8c601a | 174 | /* |
48f74186 | 175 | * The blocked_hash is used to find POSIX lock loops for deadlock detection. |
7b2296af | 176 | * It is protected by blocked_lock_lock. |
48f74186 JL |
177 | * |
178 | * We hash locks by lockowner in order to optimize searching for the lock a | |
179 | * particular lockowner is waiting on. | |
180 | * | |
181 | * FIXME: make this value scale via some heuristic? We generally will want more | |
182 | * buckets when we have more lockowners holding locks, but that's a little | |
183 | * difficult to determine without knowing what the workload will look like. | |
1c8c601a | 184 | */ |
48f74186 JL |
185 | #define BLOCKED_HASH_BITS 7 |
186 | static DEFINE_HASHTABLE(blocked_hash, BLOCKED_HASH_BITS); | |
88974691 | 187 | |
1c8c601a | 188 | /* |
7b2296af JL |
189 | * This lock protects the blocked_hash. Generally, if you're accessing it, you |
190 | * want to be holding this lock. | |
1c8c601a | 191 | * |
ada5c1da N |
192 | * In addition, it also protects the fl->fl_blocked_requests list, and the |
193 | * fl->fl_blocker pointer for file_lock structures that are acting as lock | |
194 | * requests (in contrast to those that are acting as records of acquired locks). | |
1c8c601a JL |
195 | * |
196 | * Note that when we acquire this lock in order to change the above fields, | |
6109c850 | 197 | * we often hold the flc_lock as well. In certain cases, when reading the fields |
1c8c601a | 198 | * protected by this lock, we can skip acquiring it iff we already hold the |
6109c850 | 199 | * flc_lock. |
1c8c601a | 200 | */ |
7b2296af | 201 | static DEFINE_SPINLOCK(blocked_lock_lock); |
1da177e4 | 202 | |
4a075e39 | 203 | static struct kmem_cache *flctx_cache __read_mostly; |
e18b890b | 204 | static struct kmem_cache *filelock_cache __read_mostly; |
1da177e4 | 205 | |
4a075e39 | 206 | static struct file_lock_context * |
5c1c669a | 207 | locks_get_lock_context(struct inode *inode, int type) |
4a075e39 | 208 | { |
128a3785 | 209 | struct file_lock_context *ctx; |
4a075e39 | 210 | |
128a3785 DV |
211 | /* paired with cmpxchg() below */ |
212 | ctx = smp_load_acquire(&inode->i_flctx); | |
213 | if (likely(ctx) || type == F_UNLCK) | |
4a075e39 JL |
214 | goto out; |
215 | ||
128a3785 DV |
216 | ctx = kmem_cache_alloc(flctx_cache, GFP_KERNEL); |
217 | if (!ctx) | |
4a075e39 JL |
218 | goto out; |
219 | ||
128a3785 DV |
220 | spin_lock_init(&ctx->flc_lock); |
221 | INIT_LIST_HEAD(&ctx->flc_flock); | |
222 | INIT_LIST_HEAD(&ctx->flc_posix); | |
223 | INIT_LIST_HEAD(&ctx->flc_lease); | |
4a075e39 JL |
224 | |
225 | /* | |
226 | * Assign the pointer if it's not already assigned. If it is, then | |
227 | * free the context we just allocated. | |
228 | */ | |
128a3785 DV |
229 | if (cmpxchg(&inode->i_flctx, NULL, ctx)) { |
230 | kmem_cache_free(flctx_cache, ctx); | |
231 | ctx = smp_load_acquire(&inode->i_flctx); | |
232 | } | |
4a075e39 | 233 | out: |
1890910f | 234 | trace_locks_get_lock_context(inode, type, ctx); |
128a3785 | 235 | return ctx; |
4a075e39 JL |
236 | } |
237 | ||
e24dadab JL |
238 | static void |
239 | locks_dump_ctx_list(struct list_head *list, char *list_type) | |
240 | { | |
241 | struct file_lock *fl; | |
242 | ||
243 | list_for_each_entry(fl, list, fl_list) { | |
244 | 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); | |
245 | } | |
246 | } | |
247 | ||
248 | static void | |
249 | locks_check_ctx_lists(struct inode *inode) | |
250 | { | |
251 | struct file_lock_context *ctx = inode->i_flctx; | |
252 | ||
253 | if (unlikely(!list_empty(&ctx->flc_flock) || | |
254 | !list_empty(&ctx->flc_posix) || | |
255 | !list_empty(&ctx->flc_lease))) { | |
256 | pr_warn("Leaked locks on dev=0x%x:0x%x ino=0x%lx:\n", | |
257 | MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev), | |
258 | inode->i_ino); | |
259 | locks_dump_ctx_list(&ctx->flc_flock, "FLOCK"); | |
260 | locks_dump_ctx_list(&ctx->flc_posix, "POSIX"); | |
261 | locks_dump_ctx_list(&ctx->flc_lease, "LEASE"); | |
262 | } | |
263 | } | |
264 | ||
3953704f BC |
265 | static void |
266 | locks_check_ctx_file_list(struct file *filp, struct list_head *list, | |
267 | char *list_type) | |
268 | { | |
269 | struct file_lock *fl; | |
270 | struct inode *inode = locks_inode(filp); | |
271 | ||
272 | list_for_each_entry(fl, list, fl_list) | |
273 | if (fl->fl_file == filp) | |
274 | pr_warn("Leaked %s lock on dev=0x%x:0x%x ino=0x%lx " | |
275 | " fl_owner=%p fl_flags=0x%x fl_type=0x%x fl_pid=%u\n", | |
276 | list_type, MAJOR(inode->i_sb->s_dev), | |
277 | MINOR(inode->i_sb->s_dev), inode->i_ino, | |
278 | fl->fl_owner, fl->fl_flags, fl->fl_type, fl->fl_pid); | |
279 | } | |
280 | ||
4a075e39 | 281 | void |
f27a0fe0 | 282 | locks_free_lock_context(struct inode *inode) |
4a075e39 | 283 | { |
f27a0fe0 JL |
284 | struct file_lock_context *ctx = inode->i_flctx; |
285 | ||
e24dadab JL |
286 | if (unlikely(ctx)) { |
287 | locks_check_ctx_lists(inode); | |
4a075e39 JL |
288 | kmem_cache_free(flctx_cache, ctx); |
289 | } | |
290 | } | |
291 | ||
ee19cc40 | 292 | static void locks_init_lock_heads(struct file_lock *fl) |
a51cb91d | 293 | { |
139ca04e | 294 | INIT_HLIST_NODE(&fl->fl_link); |
6dee60f6 | 295 | INIT_LIST_HEAD(&fl->fl_list); |
ada5c1da N |
296 | INIT_LIST_HEAD(&fl->fl_blocked_requests); |
297 | INIT_LIST_HEAD(&fl->fl_blocked_member); | |
ee19cc40 | 298 | init_waitqueue_head(&fl->fl_wait); |
a51cb91d MS |
299 | } |
300 | ||
1da177e4 | 301 | /* Allocate an empty lock structure. */ |
c5b1f0d9 | 302 | struct file_lock *locks_alloc_lock(void) |
1da177e4 | 303 | { |
ee19cc40 | 304 | struct file_lock *fl = kmem_cache_zalloc(filelock_cache, GFP_KERNEL); |
a51cb91d MS |
305 | |
306 | if (fl) | |
ee19cc40 | 307 | locks_init_lock_heads(fl); |
a51cb91d MS |
308 | |
309 | return fl; | |
1da177e4 | 310 | } |
c5b1f0d9 | 311 | EXPORT_SYMBOL_GPL(locks_alloc_lock); |
1da177e4 | 312 | |
a9e61e25 | 313 | void locks_release_private(struct file_lock *fl) |
47831f35 TM |
314 | { |
315 | if (fl->fl_ops) { | |
316 | if (fl->fl_ops->fl_release_private) | |
317 | fl->fl_ops->fl_release_private(fl); | |
318 | fl->fl_ops = NULL; | |
319 | } | |
47831f35 | 320 | |
5c97d7b1 | 321 | if (fl->fl_lmops) { |
cae80b30 JL |
322 | if (fl->fl_lmops->lm_put_owner) { |
323 | fl->fl_lmops->lm_put_owner(fl->fl_owner); | |
324 | fl->fl_owner = NULL; | |
325 | } | |
5c97d7b1 KM |
326 | fl->fl_lmops = NULL; |
327 | } | |
47831f35 | 328 | } |
a9e61e25 | 329 | EXPORT_SYMBOL_GPL(locks_release_private); |
47831f35 | 330 | |
1da177e4 | 331 | /* Free a lock which is not in use. */ |
05fa3135 | 332 | void locks_free_lock(struct file_lock *fl) |
1da177e4 | 333 | { |
5ce29646 | 334 | BUG_ON(waitqueue_active(&fl->fl_wait)); |
6dee60f6 | 335 | BUG_ON(!list_empty(&fl->fl_list)); |
ada5c1da N |
336 | BUG_ON(!list_empty(&fl->fl_blocked_requests)); |
337 | BUG_ON(!list_empty(&fl->fl_blocked_member)); | |
139ca04e | 338 | BUG_ON(!hlist_unhashed(&fl->fl_link)); |
1da177e4 | 339 | |
47831f35 | 340 | locks_release_private(fl); |
1da177e4 LT |
341 | kmem_cache_free(filelock_cache, fl); |
342 | } | |
05fa3135 | 343 | EXPORT_SYMBOL(locks_free_lock); |
1da177e4 | 344 | |
ed9814d8 JL |
345 | static void |
346 | locks_dispose_list(struct list_head *dispose) | |
347 | { | |
348 | struct file_lock *fl; | |
349 | ||
350 | while (!list_empty(dispose)) { | |
6dee60f6 JL |
351 | fl = list_first_entry(dispose, struct file_lock, fl_list); |
352 | list_del_init(&fl->fl_list); | |
ed9814d8 JL |
353 | locks_free_lock(fl); |
354 | } | |
355 | } | |
356 | ||
1da177e4 LT |
357 | void locks_init_lock(struct file_lock *fl) |
358 | { | |
ee19cc40 MS |
359 | memset(fl, 0, sizeof(struct file_lock)); |
360 | locks_init_lock_heads(fl); | |
1da177e4 LT |
361 | } |
362 | ||
363 | EXPORT_SYMBOL(locks_init_lock); | |
364 | ||
1da177e4 LT |
365 | /* |
366 | * Initialize a new lock from an existing file_lock structure. | |
367 | */ | |
3fe0fff1 | 368 | void locks_copy_conflock(struct file_lock *new, struct file_lock *fl) |
1da177e4 LT |
369 | { |
370 | new->fl_owner = fl->fl_owner; | |
371 | new->fl_pid = fl->fl_pid; | |
0996905f | 372 | new->fl_file = NULL; |
1da177e4 LT |
373 | new->fl_flags = fl->fl_flags; |
374 | new->fl_type = fl->fl_type; | |
375 | new->fl_start = fl->fl_start; | |
376 | new->fl_end = fl->fl_end; | |
f328296e | 377 | new->fl_lmops = fl->fl_lmops; |
0996905f | 378 | new->fl_ops = NULL; |
f328296e KM |
379 | |
380 | if (fl->fl_lmops) { | |
381 | if (fl->fl_lmops->lm_get_owner) | |
cae80b30 | 382 | fl->fl_lmops->lm_get_owner(fl->fl_owner); |
f328296e | 383 | } |
0996905f | 384 | } |
3fe0fff1 | 385 | EXPORT_SYMBOL(locks_copy_conflock); |
0996905f TM |
386 | |
387 | void locks_copy_lock(struct file_lock *new, struct file_lock *fl) | |
388 | { | |
566709bd JL |
389 | /* "new" must be a freshly-initialized lock */ |
390 | WARN_ON_ONCE(new->fl_ops); | |
0996905f | 391 | |
3fe0fff1 | 392 | locks_copy_conflock(new, fl); |
f328296e | 393 | |
0996905f | 394 | new->fl_file = fl->fl_file; |
1da177e4 | 395 | new->fl_ops = fl->fl_ops; |
47831f35 | 396 | |
f328296e KM |
397 | if (fl->fl_ops) { |
398 | if (fl->fl_ops->fl_copy_lock) | |
399 | fl->fl_ops->fl_copy_lock(new, fl); | |
400 | } | |
1da177e4 LT |
401 | } |
402 | ||
403 | EXPORT_SYMBOL(locks_copy_lock); | |
404 | ||
405 | static inline int flock_translate_cmd(int cmd) { | |
406 | if (cmd & LOCK_MAND) | |
407 | return cmd & (LOCK_MAND | LOCK_RW); | |
408 | switch (cmd) { | |
409 | case LOCK_SH: | |
410 | return F_RDLCK; | |
411 | case LOCK_EX: | |
412 | return F_WRLCK; | |
413 | case LOCK_UN: | |
414 | return F_UNLCK; | |
415 | } | |
416 | return -EINVAL; | |
417 | } | |
418 | ||
419 | /* Fill in a file_lock structure with an appropriate FLOCK lock. */ | |
6e129d00 | 420 | static struct file_lock * |
d6367d62 | 421 | flock_make_lock(struct file *filp, unsigned int cmd, struct file_lock *fl) |
1da177e4 | 422 | { |
1da177e4 | 423 | int type = flock_translate_cmd(cmd); |
6e129d00 | 424 | |
1da177e4 | 425 | if (type < 0) |
6e129d00 | 426 | return ERR_PTR(type); |
1da177e4 | 427 | |
d6367d62 N |
428 | if (fl == NULL) { |
429 | fl = locks_alloc_lock(); | |
430 | if (fl == NULL) | |
431 | return ERR_PTR(-ENOMEM); | |
432 | } else { | |
433 | locks_init_lock(fl); | |
434 | } | |
1da177e4 LT |
435 | |
436 | fl->fl_file = filp; | |
73a8f5f7 | 437 | fl->fl_owner = filp; |
1da177e4 LT |
438 | fl->fl_pid = current->tgid; |
439 | fl->fl_flags = FL_FLOCK; | |
440 | fl->fl_type = type; | |
441 | fl->fl_end = OFFSET_MAX; | |
442 | ||
6e129d00 | 443 | return fl; |
1da177e4 LT |
444 | } |
445 | ||
0ec4f431 | 446 | static int assign_type(struct file_lock *fl, long type) |
1da177e4 LT |
447 | { |
448 | switch (type) { | |
449 | case F_RDLCK: | |
450 | case F_WRLCK: | |
451 | case F_UNLCK: | |
452 | fl->fl_type = type; | |
453 | break; | |
454 | default: | |
455 | return -EINVAL; | |
456 | } | |
457 | return 0; | |
458 | } | |
459 | ||
ef12e72a BF |
460 | static int flock64_to_posix_lock(struct file *filp, struct file_lock *fl, |
461 | struct flock64 *l) | |
1da177e4 | 462 | { |
1da177e4 | 463 | switch (l->l_whence) { |
f5579f8c | 464 | case SEEK_SET: |
ef12e72a | 465 | fl->fl_start = 0; |
1da177e4 | 466 | break; |
f5579f8c | 467 | case SEEK_CUR: |
ef12e72a | 468 | fl->fl_start = filp->f_pos; |
1da177e4 | 469 | break; |
f5579f8c | 470 | case SEEK_END: |
ef12e72a | 471 | fl->fl_start = i_size_read(file_inode(filp)); |
1da177e4 LT |
472 | break; |
473 | default: | |
474 | return -EINVAL; | |
475 | } | |
ef12e72a BF |
476 | if (l->l_start > OFFSET_MAX - fl->fl_start) |
477 | return -EOVERFLOW; | |
478 | fl->fl_start += l->l_start; | |
479 | if (fl->fl_start < 0) | |
480 | return -EINVAL; | |
1da177e4 LT |
481 | |
482 | /* POSIX-1996 leaves the case l->l_len < 0 undefined; | |
483 | POSIX-2001 defines it. */ | |
4c780a46 | 484 | if (l->l_len > 0) { |
ef12e72a BF |
485 | if (l->l_len - 1 > OFFSET_MAX - fl->fl_start) |
486 | return -EOVERFLOW; | |
487 | fl->fl_end = fl->fl_start + l->l_len - 1; | |
488 | ||
4c780a46 | 489 | } else if (l->l_len < 0) { |
ef12e72a | 490 | if (fl->fl_start + l->l_len < 0) |
4c780a46 | 491 | return -EINVAL; |
ef12e72a BF |
492 | fl->fl_end = fl->fl_start - 1; |
493 | fl->fl_start += l->l_len; | |
494 | } else | |
495 | fl->fl_end = OFFSET_MAX; | |
496 | ||
1da177e4 LT |
497 | fl->fl_owner = current->files; |
498 | fl->fl_pid = current->tgid; | |
499 | fl->fl_file = filp; | |
500 | fl->fl_flags = FL_POSIX; | |
501 | fl->fl_ops = NULL; | |
502 | fl->fl_lmops = NULL; | |
503 | ||
504 | return assign_type(fl, l->l_type); | |
505 | } | |
506 | ||
ef12e72a BF |
507 | /* Verify a "struct flock" and copy it to a "struct file_lock" as a POSIX |
508 | * style lock. | |
509 | */ | |
510 | static int flock_to_posix_lock(struct file *filp, struct file_lock *fl, | |
511 | struct flock *l) | |
1da177e4 | 512 | { |
ef12e72a BF |
513 | struct flock64 ll = { |
514 | .l_type = l->l_type, | |
515 | .l_whence = l->l_whence, | |
516 | .l_start = l->l_start, | |
517 | .l_len = l->l_len, | |
518 | }; | |
519 | ||
520 | return flock64_to_posix_lock(filp, fl, &ll); | |
1da177e4 | 521 | } |
1da177e4 LT |
522 | |
523 | /* default lease lock manager operations */ | |
4d01b7f5 JL |
524 | static bool |
525 | lease_break_callback(struct file_lock *fl) | |
1da177e4 LT |
526 | { |
527 | kill_fasync(&fl->fl_fasync, SIGIO, POLL_MSG); | |
4d01b7f5 | 528 | return false; |
1da177e4 LT |
529 | } |
530 | ||
1c7dd2ff JL |
531 | static void |
532 | lease_setup(struct file_lock *fl, void **priv) | |
533 | { | |
534 | struct file *filp = fl->fl_file; | |
535 | struct fasync_struct *fa = *priv; | |
536 | ||
537 | /* | |
538 | * fasync_insert_entry() returns the old entry if any. If there was no | |
539 | * old entry, then it used "priv" and inserted it into the fasync list. | |
540 | * Clear the pointer to indicate that it shouldn't be freed. | |
541 | */ | |
542 | if (!fasync_insert_entry(fa->fa_fd, filp, &fl->fl_fasync, fa)) | |
543 | *priv = NULL; | |
544 | ||
01919134 | 545 | __f_setown(filp, task_pid(current), PIDTYPE_TGID, 0); |
1c7dd2ff JL |
546 | } |
547 | ||
7b021967 | 548 | static const struct lock_manager_operations lease_manager_ops = { |
8fb47a4f | 549 | .lm_break = lease_break_callback, |
8fb47a4f | 550 | .lm_change = lease_modify, |
1c7dd2ff | 551 | .lm_setup = lease_setup, |
1da177e4 LT |
552 | }; |
553 | ||
554 | /* | |
555 | * Initialize a lease, use the default lock manager operations | |
556 | */ | |
0ec4f431 | 557 | static int lease_init(struct file *filp, long type, struct file_lock *fl) |
447a5647 | 558 | { |
75dff55a TM |
559 | if (assign_type(fl, type) != 0) |
560 | return -EINVAL; | |
561 | ||
7ca76311 | 562 | fl->fl_owner = filp; |
1da177e4 LT |
563 | fl->fl_pid = current->tgid; |
564 | ||
565 | fl->fl_file = filp; | |
566 | fl->fl_flags = FL_LEASE; | |
1da177e4 LT |
567 | fl->fl_start = 0; |
568 | fl->fl_end = OFFSET_MAX; | |
569 | fl->fl_ops = NULL; | |
570 | fl->fl_lmops = &lease_manager_ops; | |
571 | return 0; | |
572 | } | |
573 | ||
574 | /* Allocate a file_lock initialised to this type of lease */ | |
0ec4f431 | 575 | static struct file_lock *lease_alloc(struct file *filp, long type) |
1da177e4 LT |
576 | { |
577 | struct file_lock *fl = locks_alloc_lock(); | |
75dff55a | 578 | int error = -ENOMEM; |
1da177e4 LT |
579 | |
580 | if (fl == NULL) | |
e32b8ee2 | 581 | return ERR_PTR(error); |
1da177e4 LT |
582 | |
583 | error = lease_init(filp, type, fl); | |
75dff55a TM |
584 | if (error) { |
585 | locks_free_lock(fl); | |
e32b8ee2 | 586 | return ERR_PTR(error); |
75dff55a | 587 | } |
e32b8ee2 | 588 | return fl; |
1da177e4 LT |
589 | } |
590 | ||
591 | /* Check if two locks overlap each other. | |
592 | */ | |
593 | static inline int locks_overlap(struct file_lock *fl1, struct file_lock *fl2) | |
594 | { | |
595 | return ((fl1->fl_end >= fl2->fl_start) && | |
596 | (fl2->fl_end >= fl1->fl_start)); | |
597 | } | |
598 | ||
599 | /* | |
600 | * Check whether two locks have the same owner. | |
601 | */ | |
33443c42 | 602 | static int posix_same_owner(struct file_lock *fl1, struct file_lock *fl2) |
1da177e4 | 603 | { |
8fb47a4f | 604 | if (fl1->fl_lmops && fl1->fl_lmops->lm_compare_owner) |
1da177e4 | 605 | return fl2->fl_lmops == fl1->fl_lmops && |
8fb47a4f | 606 | fl1->fl_lmops->lm_compare_owner(fl1, fl2); |
1da177e4 LT |
607 | return fl1->fl_owner == fl2->fl_owner; |
608 | } | |
609 | ||
6109c850 | 610 | /* Must be called with the flc_lock held! */ |
6ca10ed8 | 611 | static void locks_insert_global_locks(struct file_lock *fl) |
88974691 | 612 | { |
7c3f654d PZ |
613 | struct file_lock_list_struct *fll = this_cpu_ptr(&file_lock_list); |
614 | ||
aba37660 PZ |
615 | percpu_rwsem_assert_held(&file_rwsem); |
616 | ||
7c3f654d | 617 | spin_lock(&fll->lock); |
7012b02a | 618 | fl->fl_link_cpu = smp_processor_id(); |
7c3f654d PZ |
619 | hlist_add_head(&fl->fl_link, &fll->hlist); |
620 | spin_unlock(&fll->lock); | |
88974691 JL |
621 | } |
622 | ||
6109c850 | 623 | /* Must be called with the flc_lock held! */ |
6ca10ed8 | 624 | static void locks_delete_global_locks(struct file_lock *fl) |
88974691 | 625 | { |
7c3f654d PZ |
626 | struct file_lock_list_struct *fll; |
627 | ||
aba37660 PZ |
628 | percpu_rwsem_assert_held(&file_rwsem); |
629 | ||
7012b02a JL |
630 | /* |
631 | * Avoid taking lock if already unhashed. This is safe since this check | |
6109c850 | 632 | * is done while holding the flc_lock, and new insertions into the list |
7012b02a JL |
633 | * also require that it be held. |
634 | */ | |
635 | if (hlist_unhashed(&fl->fl_link)) | |
636 | return; | |
7c3f654d PZ |
637 | |
638 | fll = per_cpu_ptr(&file_lock_list, fl->fl_link_cpu); | |
639 | spin_lock(&fll->lock); | |
139ca04e | 640 | hlist_del_init(&fl->fl_link); |
7c3f654d | 641 | spin_unlock(&fll->lock); |
88974691 JL |
642 | } |
643 | ||
3999e493 JL |
644 | static unsigned long |
645 | posix_owner_key(struct file_lock *fl) | |
646 | { | |
647 | if (fl->fl_lmops && fl->fl_lmops->lm_owner_key) | |
648 | return fl->fl_lmops->lm_owner_key(fl); | |
649 | return (unsigned long)fl->fl_owner; | |
650 | } | |
651 | ||
6ca10ed8 | 652 | static void locks_insert_global_blocked(struct file_lock *waiter) |
88974691 | 653 | { |
663d5af7 DW |
654 | lockdep_assert_held(&blocked_lock_lock); |
655 | ||
3999e493 | 656 | hash_add(blocked_hash, &waiter->fl_link, posix_owner_key(waiter)); |
88974691 JL |
657 | } |
658 | ||
6ca10ed8 | 659 | static void locks_delete_global_blocked(struct file_lock *waiter) |
88974691 | 660 | { |
663d5af7 DW |
661 | lockdep_assert_held(&blocked_lock_lock); |
662 | ||
48f74186 | 663 | hash_del(&waiter->fl_link); |
88974691 JL |
664 | } |
665 | ||
1da177e4 LT |
666 | /* Remove waiter from blocker's block list. |
667 | * When blocker ends up pointing to itself then the list is empty. | |
1c8c601a | 668 | * |
7b2296af | 669 | * Must be called with blocked_lock_lock held. |
1da177e4 | 670 | */ |
33443c42 | 671 | static void __locks_delete_block(struct file_lock *waiter) |
1da177e4 | 672 | { |
88974691 | 673 | locks_delete_global_blocked(waiter); |
ada5c1da N |
674 | list_del_init(&waiter->fl_blocked_member); |
675 | waiter->fl_blocker = NULL; | |
1da177e4 LT |
676 | } |
677 | ||
ad6bbd8b N |
678 | static void __locks_wake_up_blocks(struct file_lock *blocker) |
679 | { | |
680 | while (!list_empty(&blocker->fl_blocked_requests)) { | |
681 | struct file_lock *waiter; | |
682 | ||
683 | waiter = list_first_entry(&blocker->fl_blocked_requests, | |
684 | struct file_lock, fl_blocked_member); | |
685 | __locks_delete_block(waiter); | |
686 | if (waiter->fl_lmops && waiter->fl_lmops->lm_notify) | |
687 | waiter->fl_lmops->lm_notify(waiter); | |
688 | else | |
689 | wake_up(&waiter->fl_wait); | |
690 | } | |
691 | } | |
692 | ||
1a9e64a7 | 693 | static void locks_delete_block(struct file_lock *waiter) |
1da177e4 | 694 | { |
7b2296af | 695 | spin_lock(&blocked_lock_lock); |
1da177e4 | 696 | __locks_delete_block(waiter); |
7b2296af | 697 | spin_unlock(&blocked_lock_lock); |
1da177e4 LT |
698 | } |
699 | ||
700 | /* Insert waiter into blocker's block list. | |
701 | * We use a circular list so that processes can be easily woken up in | |
702 | * the order they blocked. The documentation doesn't require this but | |
703 | * it seems like the reasonable thing to do. | |
1c8c601a | 704 | * |
6109c850 | 705 | * Must be called with both the flc_lock and blocked_lock_lock held. The |
ada5c1da N |
706 | * fl_blocked_requests list itself is protected by the blocked_lock_lock, |
707 | * but by ensuring that the flc_lock is also held on insertions we can avoid | |
708 | * taking the blocked_lock_lock in some cases when we see that the | |
709 | * fl_blocked_requests list is empty. | |
1da177e4 | 710 | */ |
1c8c601a JL |
711 | static void __locks_insert_block(struct file_lock *blocker, |
712 | struct file_lock *waiter) | |
1da177e4 | 713 | { |
ada5c1da N |
714 | BUG_ON(!list_empty(&waiter->fl_blocked_member)); |
715 | waiter->fl_blocker = blocker; | |
716 | list_add_tail(&waiter->fl_blocked_member, &blocker->fl_blocked_requests); | |
cff2fce5 | 717 | if (IS_POSIX(blocker) && !IS_OFDLCK(blocker)) |
1c8c601a JL |
718 | locks_insert_global_blocked(waiter); |
719 | } | |
720 | ||
6109c850 | 721 | /* Must be called with flc_lock held. */ |
1c8c601a JL |
722 | static void locks_insert_block(struct file_lock *blocker, |
723 | struct file_lock *waiter) | |
724 | { | |
7b2296af | 725 | spin_lock(&blocked_lock_lock); |
1c8c601a | 726 | __locks_insert_block(blocker, waiter); |
7b2296af | 727 | spin_unlock(&blocked_lock_lock); |
1da177e4 LT |
728 | } |
729 | ||
1cb36012 JL |
730 | /* |
731 | * Wake up processes blocked waiting for blocker. | |
732 | * | |
6109c850 | 733 | * Must be called with the inode->flc_lock held! |
1da177e4 LT |
734 | */ |
735 | static void locks_wake_up_blocks(struct file_lock *blocker) | |
736 | { | |
4e8c765d JL |
737 | /* |
738 | * Avoid taking global lock if list is empty. This is safe since new | |
6109c850 | 739 | * blocked requests are only added to the list under the flc_lock, and |
ada5c1da N |
740 | * the flc_lock is always held here. Note that removal from the |
741 | * fl_blocked_requests list does not require the flc_lock, so we must | |
742 | * recheck list_empty() after acquiring the blocked_lock_lock. | |
4e8c765d | 743 | */ |
ada5c1da | 744 | if (list_empty(&blocker->fl_blocked_requests)) |
4e8c765d JL |
745 | return; |
746 | ||
7b2296af | 747 | spin_lock(&blocked_lock_lock); |
ad6bbd8b | 748 | __locks_wake_up_blocks(blocker); |
7b2296af | 749 | spin_unlock(&blocked_lock_lock); |
1da177e4 LT |
750 | } |
751 | ||
5263e31e | 752 | static void |
e084c1bd | 753 | locks_insert_lock_ctx(struct file_lock *fl, struct list_head *before) |
5263e31e | 754 | { |
5263e31e JL |
755 | list_add_tail(&fl->fl_list, before); |
756 | locks_insert_global_locks(fl); | |
757 | } | |
758 | ||
8634b51f | 759 | static void |
e084c1bd | 760 | locks_unlink_lock_ctx(struct file_lock *fl) |
1da177e4 | 761 | { |
88974691 | 762 | locks_delete_global_locks(fl); |
8634b51f | 763 | list_del_init(&fl->fl_list); |
1da177e4 | 764 | locks_wake_up_blocks(fl); |
24cbe784 JL |
765 | } |
766 | ||
8634b51f | 767 | static void |
e084c1bd | 768 | locks_delete_lock_ctx(struct file_lock *fl, struct list_head *dispose) |
24cbe784 | 769 | { |
e084c1bd | 770 | locks_unlink_lock_ctx(fl); |
ed9814d8 | 771 | if (dispose) |
6dee60f6 | 772 | list_add(&fl->fl_list, dispose); |
ed9814d8 JL |
773 | else |
774 | locks_free_lock(fl); | |
1da177e4 LT |
775 | } |
776 | ||
777 | /* Determine if lock sys_fl blocks lock caller_fl. Common functionality | |
778 | * checks for shared/exclusive status of overlapping locks. | |
779 | */ | |
780 | static int locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl) | |
781 | { | |
782 | if (sys_fl->fl_type == F_WRLCK) | |
783 | return 1; | |
784 | if (caller_fl->fl_type == F_WRLCK) | |
785 | return 1; | |
786 | return 0; | |
787 | } | |
788 | ||
789 | /* Determine if lock sys_fl blocks lock caller_fl. POSIX specific | |
790 | * checking before calling the locks_conflict(). | |
791 | */ | |
792 | static int posix_locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl) | |
793 | { | |
794 | /* POSIX locks owned by the same process do not conflict with | |
795 | * each other. | |
796 | */ | |
9b8c8695 | 797 | if (posix_same_owner(caller_fl, sys_fl)) |
1da177e4 LT |
798 | return (0); |
799 | ||
800 | /* Check whether they overlap */ | |
801 | if (!locks_overlap(caller_fl, sys_fl)) | |
802 | return 0; | |
803 | ||
804 | return (locks_conflict(caller_fl, sys_fl)); | |
805 | } | |
806 | ||
807 | /* Determine if lock sys_fl blocks lock caller_fl. FLOCK specific | |
808 | * checking before calling the locks_conflict(). | |
809 | */ | |
810 | static int flock_locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl) | |
811 | { | |
812 | /* FLOCK locks referring to the same filp do not conflict with | |
813 | * each other. | |
814 | */ | |
9b8c8695 | 815 | if (caller_fl->fl_file == sys_fl->fl_file) |
1da177e4 LT |
816 | return (0); |
817 | if ((caller_fl->fl_type & LOCK_MAND) || (sys_fl->fl_type & LOCK_MAND)) | |
818 | return 0; | |
819 | ||
820 | return (locks_conflict(caller_fl, sys_fl)); | |
821 | } | |
822 | ||
6d34ac19 | 823 | void |
9d6a8c5c | 824 | posix_test_lock(struct file *filp, struct file_lock *fl) |
1da177e4 LT |
825 | { |
826 | struct file_lock *cfl; | |
bd61e0a9 | 827 | struct file_lock_context *ctx; |
c568d683 | 828 | struct inode *inode = locks_inode(filp); |
1da177e4 | 829 | |
128a3785 | 830 | ctx = smp_load_acquire(&inode->i_flctx); |
bd61e0a9 JL |
831 | if (!ctx || list_empty_careful(&ctx->flc_posix)) { |
832 | fl->fl_type = F_UNLCK; | |
833 | return; | |
834 | } | |
835 | ||
6109c850 | 836 | spin_lock(&ctx->flc_lock); |
bd61e0a9 JL |
837 | list_for_each_entry(cfl, &ctx->flc_posix, fl_list) { |
838 | if (posix_locks_conflict(fl, cfl)) { | |
839 | locks_copy_conflock(fl, cfl); | |
bd61e0a9 JL |
840 | goto out; |
841 | } | |
1da177e4 | 842 | } |
bd61e0a9 JL |
843 | fl->fl_type = F_UNLCK; |
844 | out: | |
6109c850 | 845 | spin_unlock(&ctx->flc_lock); |
6d34ac19 | 846 | return; |
1da177e4 | 847 | } |
1da177e4 LT |
848 | EXPORT_SYMBOL(posix_test_lock); |
849 | ||
b533184f BF |
850 | /* |
851 | * Deadlock detection: | |
852 | * | |
853 | * We attempt to detect deadlocks that are due purely to posix file | |
854 | * locks. | |
1da177e4 | 855 | * |
b533184f BF |
856 | * We assume that a task can be waiting for at most one lock at a time. |
857 | * So for any acquired lock, the process holding that lock may be | |
858 | * waiting on at most one other lock. That lock in turns may be held by | |
859 | * someone waiting for at most one other lock. Given a requested lock | |
860 | * caller_fl which is about to wait for a conflicting lock block_fl, we | |
861 | * follow this chain of waiters to ensure we are not about to create a | |
862 | * cycle. | |
1da177e4 | 863 | * |
b533184f BF |
864 | * Since we do this before we ever put a process to sleep on a lock, we |
865 | * are ensured that there is never a cycle; that is what guarantees that | |
866 | * the while() loop in posix_locks_deadlock() eventually completes. | |
97855b49 | 867 | * |
b533184f BF |
868 | * Note: the above assumption may not be true when handling lock |
869 | * requests from a broken NFS client. It may also fail in the presence | |
870 | * of tasks (such as posix threads) sharing the same open file table. | |
b533184f | 871 | * To handle those cases, we just bail out after a few iterations. |
57b65325 | 872 | * |
cff2fce5 | 873 | * For FL_OFDLCK locks, the owner is the filp, not the files_struct. |
57b65325 JL |
874 | * Because the owner is not even nominally tied to a thread of |
875 | * execution, the deadlock detection below can't reasonably work well. Just | |
876 | * skip it for those. | |
877 | * | |
cff2fce5 | 878 | * In principle, we could do a more limited deadlock detection on FL_OFDLCK |
57b65325 JL |
879 | * locks that just checks for the case where two tasks are attempting to |
880 | * upgrade from read to write locks on the same inode. | |
1da177e4 | 881 | */ |
97855b49 BF |
882 | |
883 | #define MAX_DEADLK_ITERATIONS 10 | |
884 | ||
b533184f BF |
885 | /* Find a lock that the owner of the given block_fl is blocking on. */ |
886 | static struct file_lock *what_owner_is_waiting_for(struct file_lock *block_fl) | |
887 | { | |
888 | struct file_lock *fl; | |
889 | ||
3999e493 | 890 | hash_for_each_possible(blocked_hash, fl, fl_link, posix_owner_key(block_fl)) { |
b533184f | 891 | if (posix_same_owner(fl, block_fl)) |
ada5c1da | 892 | return fl->fl_blocker; |
b533184f BF |
893 | } |
894 | return NULL; | |
895 | } | |
896 | ||
7b2296af | 897 | /* Must be called with the blocked_lock_lock held! */ |
b0904e14 | 898 | static int posix_locks_deadlock(struct file_lock *caller_fl, |
1da177e4 LT |
899 | struct file_lock *block_fl) |
900 | { | |
97855b49 | 901 | int i = 0; |
1da177e4 | 902 | |
663d5af7 DW |
903 | lockdep_assert_held(&blocked_lock_lock); |
904 | ||
57b65325 JL |
905 | /* |
906 | * This deadlock detector can't reasonably detect deadlocks with | |
cff2fce5 | 907 | * FL_OFDLCK locks, since they aren't owned by a process, per-se. |
57b65325 | 908 | */ |
cff2fce5 | 909 | if (IS_OFDLCK(caller_fl)) |
57b65325 JL |
910 | return 0; |
911 | ||
b533184f BF |
912 | while ((block_fl = what_owner_is_waiting_for(block_fl))) { |
913 | if (i++ > MAX_DEADLK_ITERATIONS) | |
914 | return 0; | |
915 | if (posix_same_owner(caller_fl, block_fl)) | |
916 | return 1; | |
1da177e4 LT |
917 | } |
918 | return 0; | |
919 | } | |
920 | ||
1da177e4 | 921 | /* Try to create a FLOCK lock on filp. We always insert new FLOCK locks |
02888f41 | 922 | * after any leases, but before any posix locks. |
f475ae95 TM |
923 | * |
924 | * Note that if called with an FL_EXISTS argument, the caller may determine | |
925 | * whether or not a lock was successfully freed by testing the return | |
926 | * value for -ENOENT. | |
1da177e4 | 927 | */ |
bcd7f78d | 928 | static int flock_lock_inode(struct inode *inode, struct file_lock *request) |
1da177e4 | 929 | { |
993dfa87 | 930 | struct file_lock *new_fl = NULL; |
5263e31e JL |
931 | struct file_lock *fl; |
932 | struct file_lock_context *ctx; | |
1da177e4 | 933 | int error = 0; |
5263e31e | 934 | bool found = false; |
ed9814d8 | 935 | LIST_HEAD(dispose); |
1da177e4 | 936 | |
5c1c669a JL |
937 | ctx = locks_get_lock_context(inode, request->fl_type); |
938 | if (!ctx) { | |
939 | if (request->fl_type != F_UNLCK) | |
940 | return -ENOMEM; | |
941 | return (request->fl_flags & FL_EXISTS) ? -ENOENT : 0; | |
942 | } | |
5263e31e | 943 | |
b89f4321 | 944 | if (!(request->fl_flags & FL_ACCESS) && (request->fl_type != F_UNLCK)) { |
84d535ad | 945 | new_fl = locks_alloc_lock(); |
b89f4321 AB |
946 | if (!new_fl) |
947 | return -ENOMEM; | |
84d535ad PE |
948 | } |
949 | ||
87709e28 | 950 | percpu_down_read_preempt_disable(&file_rwsem); |
6109c850 | 951 | spin_lock(&ctx->flc_lock); |
b89f4321 AB |
952 | if (request->fl_flags & FL_ACCESS) |
953 | goto find_conflict; | |
954 | ||
5263e31e | 955 | list_for_each_entry(fl, &ctx->flc_flock, fl_list) { |
bcd7f78d | 956 | if (request->fl_file != fl->fl_file) |
1da177e4 | 957 | continue; |
993dfa87 | 958 | if (request->fl_type == fl->fl_type) |
1da177e4 | 959 | goto out; |
5263e31e | 960 | found = true; |
e084c1bd | 961 | locks_delete_lock_ctx(fl, &dispose); |
1da177e4 LT |
962 | break; |
963 | } | |
1da177e4 | 964 | |
f475ae95 TM |
965 | if (request->fl_type == F_UNLCK) { |
966 | if ((request->fl_flags & FL_EXISTS) && !found) | |
967 | error = -ENOENT; | |
993dfa87 | 968 | goto out; |
f475ae95 | 969 | } |
1da177e4 | 970 | |
f07f18dd | 971 | find_conflict: |
5263e31e | 972 | list_for_each_entry(fl, &ctx->flc_flock, fl_list) { |
993dfa87 | 973 | if (!flock_locks_conflict(request, fl)) |
1da177e4 LT |
974 | continue; |
975 | error = -EAGAIN; | |
bde74e4b MS |
976 | if (!(request->fl_flags & FL_SLEEP)) |
977 | goto out; | |
978 | error = FILE_LOCK_DEFERRED; | |
979 | locks_insert_block(fl, request); | |
1da177e4 LT |
980 | goto out; |
981 | } | |
f07f18dd TM |
982 | if (request->fl_flags & FL_ACCESS) |
983 | goto out; | |
993dfa87 | 984 | locks_copy_lock(new_fl, request); |
e084c1bd | 985 | locks_insert_lock_ctx(new_fl, &ctx->flc_flock); |
993dfa87 | 986 | new_fl = NULL; |
9cedc194 | 987 | error = 0; |
1da177e4 LT |
988 | |
989 | out: | |
6109c850 | 990 | spin_unlock(&ctx->flc_lock); |
87709e28 | 991 | percpu_up_read_preempt_enable(&file_rwsem); |
993dfa87 TM |
992 | if (new_fl) |
993 | locks_free_lock(new_fl); | |
ed9814d8 | 994 | locks_dispose_list(&dispose); |
c883da31 | 995 | trace_flock_lock_inode(inode, request, error); |
1da177e4 LT |
996 | return error; |
997 | } | |
998 | ||
b4d629a3 JL |
999 | static int posix_lock_inode(struct inode *inode, struct file_lock *request, |
1000 | struct file_lock *conflock) | |
1da177e4 | 1001 | { |
bd61e0a9 | 1002 | struct file_lock *fl, *tmp; |
39005d02 MS |
1003 | struct file_lock *new_fl = NULL; |
1004 | struct file_lock *new_fl2 = NULL; | |
1da177e4 LT |
1005 | struct file_lock *left = NULL; |
1006 | struct file_lock *right = NULL; | |
bd61e0a9 | 1007 | struct file_lock_context *ctx; |
b9746ef8 JL |
1008 | int error; |
1009 | bool added = false; | |
ed9814d8 | 1010 | LIST_HEAD(dispose); |
1da177e4 | 1011 | |
5c1c669a | 1012 | ctx = locks_get_lock_context(inode, request->fl_type); |
bd61e0a9 | 1013 | if (!ctx) |
5c1c669a | 1014 | return (request->fl_type == F_UNLCK) ? 0 : -ENOMEM; |
bd61e0a9 | 1015 | |
1da177e4 LT |
1016 | /* |
1017 | * We may need two file_lock structures for this operation, | |
1018 | * so we get them in advance to avoid races. | |
39005d02 MS |
1019 | * |
1020 | * In some cases we can be sure, that no new locks will be needed | |
1da177e4 | 1021 | */ |
39005d02 MS |
1022 | if (!(request->fl_flags & FL_ACCESS) && |
1023 | (request->fl_type != F_UNLCK || | |
1024 | request->fl_start != 0 || request->fl_end != OFFSET_MAX)) { | |
1025 | new_fl = locks_alloc_lock(); | |
1026 | new_fl2 = locks_alloc_lock(); | |
1027 | } | |
1da177e4 | 1028 | |
87709e28 | 1029 | percpu_down_read_preempt_disable(&file_rwsem); |
6109c850 | 1030 | spin_lock(&ctx->flc_lock); |
1cb36012 JL |
1031 | /* |
1032 | * New lock request. Walk all POSIX locks and look for conflicts. If | |
1033 | * there are any, either return error or put the request on the | |
48f74186 | 1034 | * blocker's list of waiters and the global blocked_hash. |
1cb36012 | 1035 | */ |
1da177e4 | 1036 | if (request->fl_type != F_UNLCK) { |
bd61e0a9 | 1037 | list_for_each_entry(fl, &ctx->flc_posix, fl_list) { |
1da177e4 LT |
1038 | if (!posix_locks_conflict(request, fl)) |
1039 | continue; | |
5842add2 | 1040 | if (conflock) |
3fe0fff1 | 1041 | locks_copy_conflock(conflock, fl); |
1da177e4 LT |
1042 | error = -EAGAIN; |
1043 | if (!(request->fl_flags & FL_SLEEP)) | |
1044 | goto out; | |
1c8c601a JL |
1045 | /* |
1046 | * Deadlock detection and insertion into the blocked | |
1047 | * locks list must be done while holding the same lock! | |
1048 | */ | |
1da177e4 | 1049 | error = -EDEADLK; |
7b2296af | 1050 | spin_lock(&blocked_lock_lock); |
1c8c601a JL |
1051 | if (likely(!posix_locks_deadlock(request, fl))) { |
1052 | error = FILE_LOCK_DEFERRED; | |
1053 | __locks_insert_block(fl, request); | |
1054 | } | |
7b2296af | 1055 | spin_unlock(&blocked_lock_lock); |
1da177e4 LT |
1056 | goto out; |
1057 | } | |
1058 | } | |
1059 | ||
1060 | /* If we're just looking for a conflict, we're done. */ | |
1061 | error = 0; | |
1062 | if (request->fl_flags & FL_ACCESS) | |
1063 | goto out; | |
1064 | ||
bd61e0a9 JL |
1065 | /* Find the first old lock with the same owner as the new lock */ |
1066 | list_for_each_entry(fl, &ctx->flc_posix, fl_list) { | |
1067 | if (posix_same_owner(request, fl)) | |
1068 | break; | |
1da177e4 LT |
1069 | } |
1070 | ||
1cb36012 | 1071 | /* Process locks with this owner. */ |
bd61e0a9 JL |
1072 | list_for_each_entry_safe_from(fl, tmp, &ctx->flc_posix, fl_list) { |
1073 | if (!posix_same_owner(request, fl)) | |
1074 | break; | |
1075 | ||
1076 | /* Detect adjacent or overlapping regions (if same lock type) */ | |
1da177e4 | 1077 | if (request->fl_type == fl->fl_type) { |
449231d6 OK |
1078 | /* In all comparisons of start vs end, use |
1079 | * "start - 1" rather than "end + 1". If end | |
1080 | * is OFFSET_MAX, end + 1 will become negative. | |
1081 | */ | |
1da177e4 | 1082 | if (fl->fl_end < request->fl_start - 1) |
bd61e0a9 | 1083 | continue; |
1da177e4 LT |
1084 | /* If the next lock in the list has entirely bigger |
1085 | * addresses than the new one, insert the lock here. | |
1086 | */ | |
449231d6 | 1087 | if (fl->fl_start - 1 > request->fl_end) |
1da177e4 LT |
1088 | break; |
1089 | ||
1090 | /* If we come here, the new and old lock are of the | |
1091 | * same type and adjacent or overlapping. Make one | |
1092 | * lock yielding from the lower start address of both | |
1093 | * locks to the higher end address. | |
1094 | */ | |
1095 | if (fl->fl_start > request->fl_start) | |
1096 | fl->fl_start = request->fl_start; | |
1097 | else | |
1098 | request->fl_start = fl->fl_start; | |
1099 | if (fl->fl_end < request->fl_end) | |
1100 | fl->fl_end = request->fl_end; | |
1101 | else | |
1102 | request->fl_end = fl->fl_end; | |
1103 | if (added) { | |
e084c1bd | 1104 | locks_delete_lock_ctx(fl, &dispose); |
1da177e4 LT |
1105 | continue; |
1106 | } | |
1107 | request = fl; | |
b9746ef8 | 1108 | added = true; |
bd61e0a9 | 1109 | } else { |
1da177e4 LT |
1110 | /* Processing for different lock types is a bit |
1111 | * more complex. | |
1112 | */ | |
1113 | if (fl->fl_end < request->fl_start) | |
bd61e0a9 | 1114 | continue; |
1da177e4 LT |
1115 | if (fl->fl_start > request->fl_end) |
1116 | break; | |
1117 | if (request->fl_type == F_UNLCK) | |
b9746ef8 | 1118 | added = true; |
1da177e4 LT |
1119 | if (fl->fl_start < request->fl_start) |
1120 | left = fl; | |
1121 | /* If the next lock in the list has a higher end | |
1122 | * address than the new one, insert the new one here. | |
1123 | */ | |
1124 | if (fl->fl_end > request->fl_end) { | |
1125 | right = fl; | |
1126 | break; | |
1127 | } | |
1128 | if (fl->fl_start >= request->fl_start) { | |
1129 | /* The new lock completely replaces an old | |
1130 | * one (This may happen several times). | |
1131 | */ | |
1132 | if (added) { | |
e084c1bd | 1133 | locks_delete_lock_ctx(fl, &dispose); |
1da177e4 LT |
1134 | continue; |
1135 | } | |
b84d49f9 JL |
1136 | /* |
1137 | * Replace the old lock with new_fl, and | |
1138 | * remove the old one. It's safe to do the | |
1139 | * insert here since we know that we won't be | |
1140 | * using new_fl later, and that the lock is | |
1141 | * just replacing an existing lock. | |
1da177e4 | 1142 | */ |
b84d49f9 JL |
1143 | error = -ENOLCK; |
1144 | if (!new_fl) | |
1145 | goto out; | |
1146 | locks_copy_lock(new_fl, request); | |
1147 | request = new_fl; | |
1148 | new_fl = NULL; | |
e084c1bd JL |
1149 | locks_insert_lock_ctx(request, &fl->fl_list); |
1150 | locks_delete_lock_ctx(fl, &dispose); | |
b9746ef8 | 1151 | added = true; |
1da177e4 LT |
1152 | } |
1153 | } | |
1da177e4 LT |
1154 | } |
1155 | ||
0d9a490a | 1156 | /* |
1cb36012 JL |
1157 | * The above code only modifies existing locks in case of merging or |
1158 | * replacing. If new lock(s) need to be inserted all modifications are | |
1159 | * done below this, so it's safe yet to bail out. | |
0d9a490a MS |
1160 | */ |
1161 | error = -ENOLCK; /* "no luck" */ | |
1162 | if (right && left == right && !new_fl2) | |
1163 | goto out; | |
1164 | ||
1da177e4 LT |
1165 | error = 0; |
1166 | if (!added) { | |
f475ae95 TM |
1167 | if (request->fl_type == F_UNLCK) { |
1168 | if (request->fl_flags & FL_EXISTS) | |
1169 | error = -ENOENT; | |
1da177e4 | 1170 | goto out; |
f475ae95 | 1171 | } |
0d9a490a MS |
1172 | |
1173 | if (!new_fl) { | |
1174 | error = -ENOLCK; | |
1175 | goto out; | |
1176 | } | |
1da177e4 | 1177 | locks_copy_lock(new_fl, request); |
e084c1bd | 1178 | locks_insert_lock_ctx(new_fl, &fl->fl_list); |
2e2f756f | 1179 | fl = new_fl; |
1da177e4 LT |
1180 | new_fl = NULL; |
1181 | } | |
1182 | if (right) { | |
1183 | if (left == right) { | |
1184 | /* The new lock breaks the old one in two pieces, | |
1185 | * so we have to use the second new lock. | |
1186 | */ | |
1187 | left = new_fl2; | |
1188 | new_fl2 = NULL; | |
1189 | locks_copy_lock(left, right); | |
e084c1bd | 1190 | locks_insert_lock_ctx(left, &fl->fl_list); |
1da177e4 LT |
1191 | } |
1192 | right->fl_start = request->fl_end + 1; | |
1193 | locks_wake_up_blocks(right); | |
1194 | } | |
1195 | if (left) { | |
1196 | left->fl_end = request->fl_start - 1; | |
1197 | locks_wake_up_blocks(left); | |
1198 | } | |
1199 | out: | |
6109c850 | 1200 | spin_unlock(&ctx->flc_lock); |
87709e28 | 1201 | percpu_up_read_preempt_enable(&file_rwsem); |
1da177e4 LT |
1202 | /* |
1203 | * Free any unused locks. | |
1204 | */ | |
1205 | if (new_fl) | |
1206 | locks_free_lock(new_fl); | |
1207 | if (new_fl2) | |
1208 | locks_free_lock(new_fl2); | |
ed9814d8 | 1209 | locks_dispose_list(&dispose); |
1890910f JL |
1210 | trace_posix_lock_inode(inode, request, error); |
1211 | ||
1da177e4 LT |
1212 | return error; |
1213 | } | |
1214 | ||
1215 | /** | |
1216 | * posix_lock_file - Apply a POSIX-style lock to a file | |
1217 | * @filp: The file to apply the lock to | |
1218 | * @fl: The lock to be applied | |
150b3934 | 1219 | * @conflock: Place to return a copy of the conflicting lock, if found. |
1da177e4 LT |
1220 | * |
1221 | * Add a POSIX style lock to a file. | |
1222 | * We merge adjacent & overlapping locks whenever possible. | |
1223 | * POSIX locks are sorted by owner task, then by starting address | |
f475ae95 TM |
1224 | * |
1225 | * Note that if called with an FL_EXISTS argument, the caller may determine | |
1226 | * whether or not a lock was successfully freed by testing the return | |
1227 | * value for -ENOENT. | |
1da177e4 | 1228 | */ |
150b3934 | 1229 | int posix_lock_file(struct file *filp, struct file_lock *fl, |
5842add2 AA |
1230 | struct file_lock *conflock) |
1231 | { | |
c568d683 | 1232 | return posix_lock_inode(locks_inode(filp), fl, conflock); |
1da177e4 | 1233 | } |
150b3934 | 1234 | EXPORT_SYMBOL(posix_lock_file); |
1da177e4 LT |
1235 | |
1236 | /** | |
29d01b22 JL |
1237 | * posix_lock_inode_wait - Apply a POSIX-style lock to a file |
1238 | * @inode: inode of file to which lock request should be applied | |
1da177e4 LT |
1239 | * @fl: The lock to be applied |
1240 | * | |
616fb38f | 1241 | * Apply a POSIX style lock request to an inode. |
1da177e4 | 1242 | */ |
616fb38f | 1243 | static int posix_lock_inode_wait(struct inode *inode, struct file_lock *fl) |
1da177e4 LT |
1244 | { |
1245 | int error; | |
1246 | might_sleep (); | |
1247 | for (;;) { | |
b4d629a3 | 1248 | error = posix_lock_inode(inode, fl, NULL); |
bde74e4b | 1249 | if (error != FILE_LOCK_DEFERRED) |
1da177e4 | 1250 | break; |
ada5c1da | 1251 | error = wait_event_interruptible(fl->fl_wait, !fl->fl_blocker); |
1da177e4 LT |
1252 | if (!error) |
1253 | continue; | |
1254 | ||
1255 | locks_delete_block(fl); | |
1256 | break; | |
1257 | } | |
1258 | return error; | |
1259 | } | |
29d01b22 | 1260 | |
9e8925b6 | 1261 | #ifdef CONFIG_MANDATORY_FILE_LOCKING |
1da177e4 LT |
1262 | /** |
1263 | * locks_mandatory_locked - Check for an active lock | |
d7a06983 | 1264 | * @file: the file to check |
1da177e4 LT |
1265 | * |
1266 | * Searches the inode's list of locks to find any POSIX locks which conflict. | |
1267 | * This function is called from locks_verify_locked() only. | |
1268 | */ | |
d7a06983 | 1269 | int locks_mandatory_locked(struct file *file) |
1da177e4 | 1270 | { |
bd61e0a9 | 1271 | int ret; |
c568d683 | 1272 | struct inode *inode = locks_inode(file); |
bd61e0a9 | 1273 | struct file_lock_context *ctx; |
1da177e4 LT |
1274 | struct file_lock *fl; |
1275 | ||
128a3785 | 1276 | ctx = smp_load_acquire(&inode->i_flctx); |
bd61e0a9 JL |
1277 | if (!ctx || list_empty_careful(&ctx->flc_posix)) |
1278 | return 0; | |
1279 | ||
1da177e4 LT |
1280 | /* |
1281 | * Search the lock list for this inode for any POSIX locks. | |
1282 | */ | |
6109c850 | 1283 | spin_lock(&ctx->flc_lock); |
bd61e0a9 JL |
1284 | ret = 0; |
1285 | list_for_each_entry(fl, &ctx->flc_posix, fl_list) { | |
73a8f5f7 | 1286 | if (fl->fl_owner != current->files && |
bd61e0a9 JL |
1287 | fl->fl_owner != file) { |
1288 | ret = -EAGAIN; | |
1da177e4 | 1289 | break; |
bd61e0a9 | 1290 | } |
1da177e4 | 1291 | } |
6109c850 | 1292 | spin_unlock(&ctx->flc_lock); |
bd61e0a9 | 1293 | return ret; |
1da177e4 LT |
1294 | } |
1295 | ||
1296 | /** | |
1297 | * locks_mandatory_area - Check for a conflicting lock | |
acc15575 | 1298 | * @inode: the file to check |
1da177e4 | 1299 | * @filp: how the file was opened (if it was) |
acc15575 CH |
1300 | * @start: first byte in the file to check |
1301 | * @end: lastbyte in the file to check | |
1302 | * @type: %F_WRLCK for a write lock, else %F_RDLCK | |
1da177e4 LT |
1303 | * |
1304 | * Searches the inode's list of locks to find any POSIX locks which conflict. | |
1da177e4 | 1305 | */ |
acc15575 CH |
1306 | int locks_mandatory_area(struct inode *inode, struct file *filp, loff_t start, |
1307 | loff_t end, unsigned char type) | |
1da177e4 LT |
1308 | { |
1309 | struct file_lock fl; | |
1310 | int error; | |
29723ade | 1311 | bool sleep = false; |
1da177e4 LT |
1312 | |
1313 | locks_init_lock(&fl); | |
1da177e4 LT |
1314 | fl.fl_pid = current->tgid; |
1315 | fl.fl_file = filp; | |
1316 | fl.fl_flags = FL_POSIX | FL_ACCESS; | |
1317 | if (filp && !(filp->f_flags & O_NONBLOCK)) | |
29723ade | 1318 | sleep = true; |
acc15575 CH |
1319 | fl.fl_type = type; |
1320 | fl.fl_start = start; | |
1321 | fl.fl_end = end; | |
1da177e4 LT |
1322 | |
1323 | for (;;) { | |
29723ade | 1324 | if (filp) { |
73a8f5f7 | 1325 | fl.fl_owner = filp; |
29723ade | 1326 | fl.fl_flags &= ~FL_SLEEP; |
b4d629a3 | 1327 | error = posix_lock_inode(inode, &fl, NULL); |
29723ade JL |
1328 | if (!error) |
1329 | break; | |
1330 | } | |
1331 | ||
1332 | if (sleep) | |
1333 | fl.fl_flags |= FL_SLEEP; | |
1334 | fl.fl_owner = current->files; | |
b4d629a3 | 1335 | error = posix_lock_inode(inode, &fl, NULL); |
bde74e4b | 1336 | if (error != FILE_LOCK_DEFERRED) |
1da177e4 | 1337 | break; |
ada5c1da | 1338 | error = wait_event_interruptible(fl.fl_wait, !fl.fl_blocker); |
1da177e4 LT |
1339 | if (!error) { |
1340 | /* | |
1341 | * If we've been sleeping someone might have | |
1342 | * changed the permissions behind our back. | |
1343 | */ | |
a16877ca | 1344 | if (__mandatory_lock(inode)) |
1da177e4 LT |
1345 | continue; |
1346 | } | |
1347 | ||
1348 | locks_delete_block(&fl); | |
1349 | break; | |
1350 | } | |
1351 | ||
1352 | return error; | |
1353 | } | |
1354 | ||
1355 | EXPORT_SYMBOL(locks_mandatory_area); | |
9e8925b6 | 1356 | #endif /* CONFIG_MANDATORY_FILE_LOCKING */ |
1da177e4 | 1357 | |
778fc546 BF |
1358 | static void lease_clear_pending(struct file_lock *fl, int arg) |
1359 | { | |
1360 | switch (arg) { | |
1361 | case F_UNLCK: | |
1362 | fl->fl_flags &= ~FL_UNLOCK_PENDING; | |
1363 | /* fall through: */ | |
1364 | case F_RDLCK: | |
1365 | fl->fl_flags &= ~FL_DOWNGRADE_PENDING; | |
1366 | } | |
1367 | } | |
1368 | ||
1da177e4 | 1369 | /* We already had a lease on this file; just change its type */ |
7448cc37 | 1370 | int lease_modify(struct file_lock *fl, int arg, struct list_head *dispose) |
1da177e4 | 1371 | { |
1da177e4 LT |
1372 | int error = assign_type(fl, arg); |
1373 | ||
1374 | if (error) | |
1375 | return error; | |
778fc546 | 1376 | lease_clear_pending(fl, arg); |
1da177e4 | 1377 | locks_wake_up_blocks(fl); |
3b6e2723 FB |
1378 | if (arg == F_UNLCK) { |
1379 | struct file *filp = fl->fl_file; | |
1380 | ||
1381 | f_delown(filp); | |
1382 | filp->f_owner.signum = 0; | |
96d6d59c BF |
1383 | fasync_helper(0, fl->fl_file, 0, &fl->fl_fasync); |
1384 | if (fl->fl_fasync != NULL) { | |
1385 | printk(KERN_ERR "locks_delete_lock: fasync == %p\n", fl->fl_fasync); | |
1386 | fl->fl_fasync = NULL; | |
1387 | } | |
e084c1bd | 1388 | locks_delete_lock_ctx(fl, dispose); |
3b6e2723 | 1389 | } |
1da177e4 LT |
1390 | return 0; |
1391 | } | |
1da177e4 LT |
1392 | EXPORT_SYMBOL(lease_modify); |
1393 | ||
778fc546 BF |
1394 | static bool past_time(unsigned long then) |
1395 | { | |
1396 | if (!then) | |
1397 | /* 0 is a special value meaning "this never expires": */ | |
1398 | return false; | |
1399 | return time_after(jiffies, then); | |
1400 | } | |
1401 | ||
c45198ed | 1402 | static void time_out_leases(struct inode *inode, struct list_head *dispose) |
1da177e4 | 1403 | { |
8634b51f JL |
1404 | struct file_lock_context *ctx = inode->i_flctx; |
1405 | struct file_lock *fl, *tmp; | |
1da177e4 | 1406 | |
6109c850 | 1407 | lockdep_assert_held(&ctx->flc_lock); |
f82b4b67 | 1408 | |
8634b51f | 1409 | list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list) { |
62af4f1f | 1410 | trace_time_out_leases(inode, fl); |
778fc546 | 1411 | if (past_time(fl->fl_downgrade_time)) |
7448cc37 | 1412 | lease_modify(fl, F_RDLCK, dispose); |
778fc546 | 1413 | if (past_time(fl->fl_break_time)) |
7448cc37 | 1414 | lease_modify(fl, F_UNLCK, dispose); |
1da177e4 LT |
1415 | } |
1416 | } | |
1417 | ||
df4e8d2c BF |
1418 | static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker) |
1419 | { | |
11afe9f7 CH |
1420 | if ((breaker->fl_flags & FL_LAYOUT) != (lease->fl_flags & FL_LAYOUT)) |
1421 | return false; | |
df4e8d2c BF |
1422 | if ((breaker->fl_flags & FL_DELEG) && (lease->fl_flags & FL_LEASE)) |
1423 | return false; | |
1424 | return locks_conflict(breaker, lease); | |
1425 | } | |
1426 | ||
03d12ddf JL |
1427 | static bool |
1428 | any_leases_conflict(struct inode *inode, struct file_lock *breaker) | |
1429 | { | |
8634b51f | 1430 | struct file_lock_context *ctx = inode->i_flctx; |
03d12ddf JL |
1431 | struct file_lock *fl; |
1432 | ||
6109c850 | 1433 | lockdep_assert_held(&ctx->flc_lock); |
03d12ddf | 1434 | |
8634b51f | 1435 | list_for_each_entry(fl, &ctx->flc_lease, fl_list) { |
03d12ddf JL |
1436 | if (leases_conflict(fl, breaker)) |
1437 | return true; | |
1438 | } | |
1439 | return false; | |
1440 | } | |
1441 | ||
1da177e4 LT |
1442 | /** |
1443 | * __break_lease - revoke all outstanding leases on file | |
1444 | * @inode: the inode of the file to return | |
df4e8d2c BF |
1445 | * @mode: O_RDONLY: break only write leases; O_WRONLY or O_RDWR: |
1446 | * break all leases | |
1447 | * @type: FL_LEASE: break leases and delegations; FL_DELEG: break | |
1448 | * only delegations | |
1da177e4 | 1449 | * |
87250dd2 | 1450 | * break_lease (inlined for speed) has checked there already is at least |
1451 | * some kind of lock (maybe a lease) on this file. Leases are broken on | |
1452 | * a call to open() or truncate(). This function can sleep unless you | |
1da177e4 LT |
1453 | * specified %O_NONBLOCK to your open(). |
1454 | */ | |
df4e8d2c | 1455 | int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) |
1da177e4 | 1456 | { |
778fc546 | 1457 | int error = 0; |
128a3785 | 1458 | struct file_lock_context *ctx; |
a901125c | 1459 | struct file_lock *new_fl, *fl, *tmp; |
1da177e4 | 1460 | unsigned long break_time; |
8737c930 | 1461 | int want_write = (mode & O_ACCMODE) != O_RDONLY; |
c45198ed | 1462 | LIST_HEAD(dispose); |
1da177e4 | 1463 | |
8737c930 | 1464 | new_fl = lease_alloc(NULL, want_write ? F_WRLCK : F_RDLCK); |
6d4b9e38 LT |
1465 | if (IS_ERR(new_fl)) |
1466 | return PTR_ERR(new_fl); | |
df4e8d2c | 1467 | new_fl->fl_flags = type; |
1da177e4 | 1468 | |
8634b51f | 1469 | /* typically we will check that ctx is non-NULL before calling */ |
128a3785 | 1470 | ctx = smp_load_acquire(&inode->i_flctx); |
8634b51f JL |
1471 | if (!ctx) { |
1472 | WARN_ON_ONCE(1); | |
1473 | return error; | |
1474 | } | |
1475 | ||
87709e28 | 1476 | percpu_down_read_preempt_disable(&file_rwsem); |
6109c850 | 1477 | spin_lock(&ctx->flc_lock); |
1da177e4 | 1478 | |
c45198ed | 1479 | time_out_leases(inode, &dispose); |
1da177e4 | 1480 | |
03d12ddf | 1481 | if (!any_leases_conflict(inode, new_fl)) |
778fc546 BF |
1482 | goto out; |
1483 | ||
1da177e4 LT |
1484 | break_time = 0; |
1485 | if (lease_break_time > 0) { | |
1486 | break_time = jiffies + lease_break_time * HZ; | |
1487 | if (break_time == 0) | |
1488 | break_time++; /* so that 0 means no break time */ | |
1489 | } | |
1490 | ||
a901125c | 1491 | list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list) { |
df4e8d2c BF |
1492 | if (!leases_conflict(fl, new_fl)) |
1493 | continue; | |
778fc546 BF |
1494 | if (want_write) { |
1495 | if (fl->fl_flags & FL_UNLOCK_PENDING) | |
1496 | continue; | |
1497 | fl->fl_flags |= FL_UNLOCK_PENDING; | |
1da177e4 | 1498 | fl->fl_break_time = break_time; |
778fc546 | 1499 | } else { |
8634b51f | 1500 | if (lease_breaking(fl)) |
778fc546 BF |
1501 | continue; |
1502 | fl->fl_flags |= FL_DOWNGRADE_PENDING; | |
1503 | fl->fl_downgrade_time = break_time; | |
1da177e4 | 1504 | } |
4d01b7f5 | 1505 | if (fl->fl_lmops->lm_break(fl)) |
e084c1bd | 1506 | locks_delete_lock_ctx(fl, &dispose); |
1da177e4 LT |
1507 | } |
1508 | ||
8634b51f | 1509 | if (list_empty(&ctx->flc_lease)) |
4d01b7f5 JL |
1510 | goto out; |
1511 | ||
843c6b2f | 1512 | if (mode & O_NONBLOCK) { |
62af4f1f | 1513 | trace_break_lease_noblock(inode, new_fl); |
1da177e4 LT |
1514 | error = -EWOULDBLOCK; |
1515 | goto out; | |
1516 | } | |
1517 | ||
1518 | restart: | |
8634b51f JL |
1519 | fl = list_first_entry(&ctx->flc_lease, struct file_lock, fl_list); |
1520 | break_time = fl->fl_break_time; | |
f1c6bb2c | 1521 | if (break_time != 0) |
1da177e4 | 1522 | break_time -= jiffies; |
f1c6bb2c JL |
1523 | if (break_time == 0) |
1524 | break_time++; | |
8634b51f | 1525 | locks_insert_block(fl, new_fl); |
62af4f1f | 1526 | trace_break_lease_block(inode, new_fl); |
6109c850 | 1527 | spin_unlock(&ctx->flc_lock); |
87709e28 | 1528 | percpu_up_read_preempt_enable(&file_rwsem); |
aba37660 | 1529 | |
c45198ed | 1530 | locks_dispose_list(&dispose); |
4321e01e | 1531 | error = wait_event_interruptible_timeout(new_fl->fl_wait, |
ada5c1da | 1532 | !new_fl->fl_blocker, break_time); |
aba37660 | 1533 | |
87709e28 | 1534 | percpu_down_read_preempt_disable(&file_rwsem); |
6109c850 | 1535 | spin_lock(&ctx->flc_lock); |
62af4f1f | 1536 | trace_break_lease_unblock(inode, new_fl); |
1c8c601a | 1537 | locks_delete_block(new_fl); |
1da177e4 | 1538 | if (error >= 0) { |
778fc546 BF |
1539 | /* |
1540 | * Wait for the next conflicting lease that has not been | |
1541 | * broken yet | |
1542 | */ | |
03d12ddf JL |
1543 | if (error == 0) |
1544 | time_out_leases(inode, &dispose); | |
1545 | if (any_leases_conflict(inode, new_fl)) | |
1546 | goto restart; | |
1da177e4 LT |
1547 | error = 0; |
1548 | } | |
1da177e4 | 1549 | out: |
6109c850 | 1550 | spin_unlock(&ctx->flc_lock); |
87709e28 | 1551 | percpu_up_read_preempt_enable(&file_rwsem); |
c45198ed | 1552 | locks_dispose_list(&dispose); |
6d4b9e38 | 1553 | locks_free_lock(new_fl); |
1da177e4 LT |
1554 | return error; |
1555 | } | |
1556 | ||
1557 | EXPORT_SYMBOL(__break_lease); | |
1558 | ||
1559 | /** | |
76c47948 | 1560 | * lease_get_mtime - update modified time of an inode with exclusive lease |
1da177e4 | 1561 | * @inode: the inode |
76c47948 | 1562 | * @time: pointer to a timespec which contains the last modified time |
1da177e4 LT |
1563 | * |
1564 | * This is to force NFS clients to flush their caches for files with | |
1565 | * exclusive leases. The justification is that if someone has an | |
a6b91919 | 1566 | * exclusive lease, then they could be modifying it. |
1da177e4 | 1567 | */ |
95582b00 | 1568 | void lease_get_mtime(struct inode *inode, struct timespec64 *time) |
1da177e4 | 1569 | { |
bfe86024 | 1570 | bool has_lease = false; |
128a3785 | 1571 | struct file_lock_context *ctx; |
8634b51f | 1572 | struct file_lock *fl; |
bfe86024 | 1573 | |
128a3785 | 1574 | ctx = smp_load_acquire(&inode->i_flctx); |
8634b51f | 1575 | if (ctx && !list_empty_careful(&ctx->flc_lease)) { |
6109c850 | 1576 | spin_lock(&ctx->flc_lock); |
8ace5dfb GT |
1577 | fl = list_first_entry_or_null(&ctx->flc_lease, |
1578 | struct file_lock, fl_list); | |
1579 | if (fl && (fl->fl_type == F_WRLCK)) | |
1580 | has_lease = true; | |
6109c850 | 1581 | spin_unlock(&ctx->flc_lock); |
bfe86024 JL |
1582 | } |
1583 | ||
1584 | if (has_lease) | |
c2050a45 | 1585 | *time = current_time(inode); |
1da177e4 LT |
1586 | } |
1587 | ||
1588 | EXPORT_SYMBOL(lease_get_mtime); | |
1589 | ||
1590 | /** | |
1591 | * fcntl_getlease - Enquire what lease is currently active | |
1592 | * @filp: the file | |
1593 | * | |
1594 | * The value returned by this function will be one of | |
1595 | * (if no lease break is pending): | |
1596 | * | |
1597 | * %F_RDLCK to indicate a shared lease is held. | |
1598 | * | |
1599 | * %F_WRLCK to indicate an exclusive lease is held. | |
1600 | * | |
1601 | * %F_UNLCK to indicate no lease is held. | |
1602 | * | |
1603 | * (if a lease break is pending): | |
1604 | * | |
1605 | * %F_RDLCK to indicate an exclusive lease needs to be | |
1606 | * changed to a shared lease (or removed). | |
1607 | * | |
1608 | * %F_UNLCK to indicate the lease needs to be removed. | |
1609 | * | |
1610 | * XXX: sfr & willy disagree over whether F_INPROGRESS | |
1611 | * should be returned to userspace. | |
1612 | */ | |
1613 | int fcntl_getlease(struct file *filp) | |
1614 | { | |
1615 | struct file_lock *fl; | |
c568d683 | 1616 | struct inode *inode = locks_inode(filp); |
128a3785 | 1617 | struct file_lock_context *ctx; |
1da177e4 | 1618 | int type = F_UNLCK; |
c45198ed | 1619 | LIST_HEAD(dispose); |
1da177e4 | 1620 | |
128a3785 | 1621 | ctx = smp_load_acquire(&inode->i_flctx); |
8634b51f | 1622 | if (ctx && !list_empty_careful(&ctx->flc_lease)) { |
5f43086b | 1623 | percpu_down_read_preempt_disable(&file_rwsem); |
6109c850 | 1624 | spin_lock(&ctx->flc_lock); |
c568d683 | 1625 | time_out_leases(inode, &dispose); |
8634b51f JL |
1626 | list_for_each_entry(fl, &ctx->flc_lease, fl_list) { |
1627 | if (fl->fl_file != filp) | |
1628 | continue; | |
778fc546 | 1629 | type = target_leasetype(fl); |
1da177e4 LT |
1630 | break; |
1631 | } | |
6109c850 | 1632 | spin_unlock(&ctx->flc_lock); |
5f43086b PZ |
1633 | percpu_up_read_preempt_enable(&file_rwsem); |
1634 | ||
8634b51f | 1635 | locks_dispose_list(&dispose); |
1da177e4 | 1636 | } |
1da177e4 LT |
1637 | return type; |
1638 | } | |
1639 | ||
24cbe784 JL |
1640 | /** |
1641 | * check_conflicting_open - see if the given dentry points to a file that has | |
1642 | * an existing open that would conflict with the | |
1643 | * desired lease. | |
1644 | * @dentry: dentry to check | |
1645 | * @arg: type of lease that we're trying to acquire | |
7fadc59c | 1646 | * @flags: current lock flags |
24cbe784 JL |
1647 | * |
1648 | * Check to see if there's an existing open fd on this file that would | |
1649 | * conflict with the lease we're trying to set. | |
1650 | */ | |
1651 | static int | |
11afe9f7 | 1652 | check_conflicting_open(const struct dentry *dentry, const long arg, int flags) |
24cbe784 JL |
1653 | { |
1654 | int ret = 0; | |
1655 | struct inode *inode = dentry->d_inode; | |
1656 | ||
11afe9f7 CH |
1657 | if (flags & FL_LAYOUT) |
1658 | return 0; | |
1659 | ||
8cf9ee50 | 1660 | if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0)) |
24cbe784 JL |
1661 | return -EAGAIN; |
1662 | ||
1663 | if ((arg == F_WRLCK) && ((d_count(dentry) > 1) || | |
1664 | (atomic_read(&inode->i_count) > 1))) | |
1665 | ret = -EAGAIN; | |
1666 | ||
1667 | return ret; | |
1668 | } | |
1669 | ||
e6f5c789 JL |
1670 | static int |
1671 | generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **priv) | |
1da177e4 | 1672 | { |
8634b51f | 1673 | struct file_lock *fl, *my_fl = NULL, *lease; |
0f7fc9e4 | 1674 | struct dentry *dentry = filp->f_path.dentry; |
c568d683 | 1675 | struct inode *inode = dentry->d_inode; |
8634b51f | 1676 | struct file_lock_context *ctx; |
df4e8d2c | 1677 | bool is_deleg = (*flp)->fl_flags & FL_DELEG; |
c1f24ef4 | 1678 | int error; |
c45198ed | 1679 | LIST_HEAD(dispose); |
1da177e4 | 1680 | |
096657b6 | 1681 | lease = *flp; |
62af4f1f JL |
1682 | trace_generic_add_lease(inode, lease); |
1683 | ||
5c1c669a JL |
1684 | /* Note that arg is never F_UNLCK here */ |
1685 | ctx = locks_get_lock_context(inode, arg); | |
8634b51f JL |
1686 | if (!ctx) |
1687 | return -ENOMEM; | |
1688 | ||
df4e8d2c BF |
1689 | /* |
1690 | * In the delegation case we need mutual exclusion with | |
1691 | * a number of operations that take the i_mutex. We trylock | |
1692 | * because delegations are an optional optimization, and if | |
1693 | * there's some chance of a conflict--we'd rather not | |
1694 | * bother, maybe that's a sign this just isn't a good file to | |
1695 | * hand out a delegation on. | |
1696 | */ | |
5955102c | 1697 | if (is_deleg && !inode_trylock(inode)) |
df4e8d2c BF |
1698 | return -EAGAIN; |
1699 | ||
1700 | if (is_deleg && arg == F_WRLCK) { | |
1701 | /* Write delegations are not currently supported: */ | |
5955102c | 1702 | inode_unlock(inode); |
df4e8d2c BF |
1703 | WARN_ON_ONCE(1); |
1704 | return -EINVAL; | |
1705 | } | |
096657b6 | 1706 | |
87709e28 | 1707 | percpu_down_read_preempt_disable(&file_rwsem); |
6109c850 | 1708 | spin_lock(&ctx->flc_lock); |
c45198ed | 1709 | time_out_leases(inode, &dispose); |
11afe9f7 | 1710 | error = check_conflicting_open(dentry, arg, lease->fl_flags); |
24cbe784 | 1711 | if (error) |
096657b6 | 1712 | goto out; |
6d5e8b05 | 1713 | |
1da177e4 LT |
1714 | /* |
1715 | * At this point, we know that if there is an exclusive | |
1716 | * lease on this file, then we hold it on this filp | |
1717 | * (otherwise our open of this file would have blocked). | |
1718 | * And if we are trying to acquire an exclusive lease, | |
1719 | * then the file is not open by anyone (including us) | |
1720 | * except for this filp. | |
1721 | */ | |
c1f24ef4 | 1722 | error = -EAGAIN; |
8634b51f | 1723 | list_for_each_entry(fl, &ctx->flc_lease, fl_list) { |
2ab99ee1 CH |
1724 | if (fl->fl_file == filp && |
1725 | fl->fl_owner == lease->fl_owner) { | |
8634b51f | 1726 | my_fl = fl; |
c1f24ef4 BF |
1727 | continue; |
1728 | } | |
8634b51f | 1729 | |
c1f24ef4 BF |
1730 | /* |
1731 | * No exclusive leases if someone else has a lease on | |
1732 | * this file: | |
1733 | */ | |
1734 | if (arg == F_WRLCK) | |
1735 | goto out; | |
1736 | /* | |
1737 | * Modifying our existing lease is OK, but no getting a | |
1738 | * new lease if someone else is opening for write: | |
1739 | */ | |
1740 | if (fl->fl_flags & FL_UNLOCK_PENDING) | |
1741 | goto out; | |
1da177e4 LT |
1742 | } |
1743 | ||
8634b51f | 1744 | if (my_fl != NULL) { |
0164bf02 JL |
1745 | lease = my_fl; |
1746 | error = lease->fl_lmops->lm_change(lease, arg, &dispose); | |
1c7dd2ff JL |
1747 | if (error) |
1748 | goto out; | |
1749 | goto out_setup; | |
1da177e4 LT |
1750 | } |
1751 | ||
1da177e4 LT |
1752 | error = -EINVAL; |
1753 | if (!leases_enable) | |
1754 | goto out; | |
1755 | ||
e084c1bd | 1756 | locks_insert_lock_ctx(lease, &ctx->flc_lease); |
24cbe784 JL |
1757 | /* |
1758 | * The check in break_lease() is lockless. It's possible for another | |
1759 | * open to race in after we did the earlier check for a conflicting | |
1760 | * open but before the lease was inserted. Check again for a | |
1761 | * conflicting open and cancel the lease if there is one. | |
1762 | * | |
1763 | * We also add a barrier here to ensure that the insertion of the lock | |
1764 | * precedes these checks. | |
1765 | */ | |
1766 | smp_mb(); | |
11afe9f7 | 1767 | error = check_conflicting_open(dentry, arg, lease->fl_flags); |
8634b51f | 1768 | if (error) { |
e084c1bd | 1769 | locks_unlink_lock_ctx(lease); |
8634b51f JL |
1770 | goto out; |
1771 | } | |
1c7dd2ff JL |
1772 | |
1773 | out_setup: | |
1774 | if (lease->fl_lmops->lm_setup) | |
1775 | lease->fl_lmops->lm_setup(lease, priv); | |
1da177e4 | 1776 | out: |
6109c850 | 1777 | spin_unlock(&ctx->flc_lock); |
87709e28 | 1778 | percpu_up_read_preempt_enable(&file_rwsem); |
c45198ed | 1779 | locks_dispose_list(&dispose); |
df4e8d2c | 1780 | if (is_deleg) |
5955102c | 1781 | inode_unlock(inode); |
8634b51f | 1782 | if (!error && !my_fl) |
1c7dd2ff | 1783 | *flp = NULL; |
1da177e4 LT |
1784 | return error; |
1785 | } | |
8335ebd9 | 1786 | |
2ab99ee1 | 1787 | static int generic_delete_lease(struct file *filp, void *owner) |
8335ebd9 | 1788 | { |
0efaa7e8 | 1789 | int error = -EAGAIN; |
8634b51f | 1790 | struct file_lock *fl, *victim = NULL; |
c568d683 | 1791 | struct inode *inode = locks_inode(filp); |
128a3785 | 1792 | struct file_lock_context *ctx; |
c45198ed | 1793 | LIST_HEAD(dispose); |
8335ebd9 | 1794 | |
128a3785 | 1795 | ctx = smp_load_acquire(&inode->i_flctx); |
8634b51f JL |
1796 | if (!ctx) { |
1797 | trace_generic_delete_lease(inode, NULL); | |
1798 | return error; | |
1799 | } | |
1800 | ||
87709e28 | 1801 | percpu_down_read_preempt_disable(&file_rwsem); |
6109c850 | 1802 | spin_lock(&ctx->flc_lock); |
8634b51f | 1803 | list_for_each_entry(fl, &ctx->flc_lease, fl_list) { |
2ab99ee1 CH |
1804 | if (fl->fl_file == filp && |
1805 | fl->fl_owner == owner) { | |
8634b51f | 1806 | victim = fl; |
0efaa7e8 | 1807 | break; |
8634b51f | 1808 | } |
8335ebd9 | 1809 | } |
a9b1b455 | 1810 | trace_generic_delete_lease(inode, victim); |
8634b51f | 1811 | if (victim) |
7448cc37 | 1812 | error = fl->fl_lmops->lm_change(victim, F_UNLCK, &dispose); |
6109c850 | 1813 | spin_unlock(&ctx->flc_lock); |
87709e28 | 1814 | percpu_up_read_preempt_enable(&file_rwsem); |
c45198ed | 1815 | locks_dispose_list(&dispose); |
0efaa7e8 | 1816 | return error; |
8335ebd9 BF |
1817 | } |
1818 | ||
1819 | /** | |
1820 | * generic_setlease - sets a lease on an open file | |
1c7dd2ff JL |
1821 | * @filp: file pointer |
1822 | * @arg: type of lease to obtain | |
1823 | * @flp: input - file_lock to use, output - file_lock inserted | |
1824 | * @priv: private data for lm_setup (may be NULL if lm_setup | |
1825 | * doesn't require it) | |
8335ebd9 BF |
1826 | * |
1827 | * The (input) flp->fl_lmops->lm_break function is required | |
1828 | * by break_lease(). | |
8335ebd9 | 1829 | */ |
e6f5c789 JL |
1830 | int generic_setlease(struct file *filp, long arg, struct file_lock **flp, |
1831 | void **priv) | |
8335ebd9 | 1832 | { |
c568d683 | 1833 | struct inode *inode = locks_inode(filp); |
8335ebd9 BF |
1834 | int error; |
1835 | ||
8e96e3b7 | 1836 | if ((!uid_eq(current_fsuid(), inode->i_uid)) && !capable(CAP_LEASE)) |
8335ebd9 BF |
1837 | return -EACCES; |
1838 | if (!S_ISREG(inode->i_mode)) | |
1839 | return -EINVAL; | |
1840 | error = security_file_lock(filp, arg); | |
1841 | if (error) | |
1842 | return error; | |
1843 | ||
8335ebd9 BF |
1844 | switch (arg) { |
1845 | case F_UNLCK: | |
2ab99ee1 | 1846 | return generic_delete_lease(filp, *priv); |
8335ebd9 BF |
1847 | case F_RDLCK: |
1848 | case F_WRLCK: | |
0efaa7e8 JL |
1849 | if (!(*flp)->fl_lmops->lm_break) { |
1850 | WARN_ON_ONCE(1); | |
1851 | return -ENOLCK; | |
1852 | } | |
11afe9f7 | 1853 | |
e6f5c789 | 1854 | return generic_add_lease(filp, arg, flp, priv); |
8335ebd9 | 1855 | default: |
8d657eb3 | 1856 | return -EINVAL; |
8335ebd9 BF |
1857 | } |
1858 | } | |
0af1a450 | 1859 | EXPORT_SYMBOL(generic_setlease); |
1da177e4 | 1860 | |
b89f4321 | 1861 | /** |
e51673aa | 1862 | * vfs_setlease - sets a lease on an open file |
1c7dd2ff JL |
1863 | * @filp: file pointer |
1864 | * @arg: type of lease to obtain | |
1865 | * @lease: file_lock to use when adding a lease | |
1866 | * @priv: private info for lm_setup when adding a lease (may be | |
1867 | * NULL if lm_setup doesn't require it) | |
e51673aa JL |
1868 | * |
1869 | * Call this to establish a lease on the file. The "lease" argument is not | |
1870 | * used for F_UNLCK requests and may be NULL. For commands that set or alter | |
80b79dd0 MCC |
1871 | * an existing lease, the ``(*lease)->fl_lmops->lm_break`` operation must be |
1872 | * set; if not, this function will return -ENOLCK (and generate a scary-looking | |
e51673aa | 1873 | * stack trace). |
1c7dd2ff JL |
1874 | * |
1875 | * The "priv" pointer is passed directly to the lm_setup function as-is. It | |
1876 | * may be NULL if the lm_setup operation doesn't require it. | |
1da177e4 | 1877 | */ |
e6f5c789 JL |
1878 | int |
1879 | vfs_setlease(struct file *filp, long arg, struct file_lock **lease, void **priv) | |
1da177e4 | 1880 | { |
de2a4a50 | 1881 | if (filp->f_op->setlease) |
f82b4b67 | 1882 | return filp->f_op->setlease(filp, arg, lease, priv); |
1c7dd2ff | 1883 | else |
f82b4b67 | 1884 | return generic_setlease(filp, arg, lease, priv); |
1da177e4 | 1885 | } |
a9933cea | 1886 | EXPORT_SYMBOL_GPL(vfs_setlease); |
1da177e4 | 1887 | |
0ceaf6c7 | 1888 | static int do_fcntl_add_lease(unsigned int fd, struct file *filp, long arg) |
1da177e4 | 1889 | { |
1c7dd2ff | 1890 | struct file_lock *fl; |
f7347ce4 | 1891 | struct fasync_struct *new; |
1da177e4 LT |
1892 | int error; |
1893 | ||
c5b1f0d9 AB |
1894 | fl = lease_alloc(filp, arg); |
1895 | if (IS_ERR(fl)) | |
1896 | return PTR_ERR(fl); | |
1da177e4 | 1897 | |
f7347ce4 LT |
1898 | new = fasync_alloc(); |
1899 | if (!new) { | |
1900 | locks_free_lock(fl); | |
1901 | return -ENOMEM; | |
1902 | } | |
1c7dd2ff | 1903 | new->fa_fd = fd; |
f7347ce4 | 1904 | |
1c7dd2ff | 1905 | error = vfs_setlease(filp, arg, &fl, (void **)&new); |
2dfb928f JL |
1906 | if (fl) |
1907 | locks_free_lock(fl); | |
f7347ce4 LT |
1908 | if (new) |
1909 | fasync_free(new); | |
1da177e4 LT |
1910 | return error; |
1911 | } | |
1912 | ||
0ceaf6c7 BF |
1913 | /** |
1914 | * fcntl_setlease - sets a lease on an open file | |
1915 | * @fd: open file descriptor | |
1916 | * @filp: file pointer | |
1917 | * @arg: type of lease to obtain | |
1918 | * | |
1919 | * Call this fcntl to establish a lease on the file. | |
1920 | * Note that you also need to call %F_SETSIG to | |
1921 | * receive a signal when the lease is broken. | |
1922 | */ | |
1923 | int fcntl_setlease(unsigned int fd, struct file *filp, long arg) | |
1924 | { | |
1925 | if (arg == F_UNLCK) | |
2ab99ee1 | 1926 | return vfs_setlease(filp, F_UNLCK, NULL, (void **)&filp); |
0ceaf6c7 BF |
1927 | return do_fcntl_add_lease(fd, filp, arg); |
1928 | } | |
1929 | ||
1da177e4 | 1930 | /** |
29d01b22 JL |
1931 | * flock_lock_inode_wait - Apply a FLOCK-style lock to a file |
1932 | * @inode: inode of the file to apply to | |
1da177e4 LT |
1933 | * @fl: The lock to be applied |
1934 | * | |
29d01b22 | 1935 | * Apply a FLOCK style lock request to an inode. |
1da177e4 | 1936 | */ |
616fb38f | 1937 | static int flock_lock_inode_wait(struct inode *inode, struct file_lock *fl) |
1da177e4 LT |
1938 | { |
1939 | int error; | |
1940 | might_sleep(); | |
1941 | for (;;) { | |
29d01b22 | 1942 | error = flock_lock_inode(inode, fl); |
bde74e4b | 1943 | if (error != FILE_LOCK_DEFERRED) |
1da177e4 | 1944 | break; |
ada5c1da | 1945 | error = wait_event_interruptible(fl->fl_wait, !fl->fl_blocker); |
1da177e4 LT |
1946 | if (!error) |
1947 | continue; | |
1948 | ||
1949 | locks_delete_block(fl); | |
1950 | break; | |
1951 | } | |
1952 | return error; | |
1953 | } | |
1954 | ||
e55c34a6 BC |
1955 | /** |
1956 | * locks_lock_inode_wait - Apply a lock to an inode | |
1957 | * @inode: inode of the file to apply to | |
1958 | * @fl: The lock to be applied | |
1959 | * | |
1960 | * Apply a POSIX or FLOCK style lock request to an inode. | |
1961 | */ | |
1962 | int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl) | |
1963 | { | |
1964 | int res = 0; | |
1965 | switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { | |
1966 | case FL_POSIX: | |
1967 | res = posix_lock_inode_wait(inode, fl); | |
1968 | break; | |
1969 | case FL_FLOCK: | |
1970 | res = flock_lock_inode_wait(inode, fl); | |
1971 | break; | |
1972 | default: | |
1973 | BUG(); | |
1974 | } | |
1975 | return res; | |
1976 | } | |
1977 | EXPORT_SYMBOL(locks_lock_inode_wait); | |
1978 | ||
1da177e4 LT |
1979 | /** |
1980 | * sys_flock: - flock() system call. | |
1981 | * @fd: the file descriptor to lock. | |
1982 | * @cmd: the type of lock to apply. | |
1983 | * | |
1984 | * Apply a %FL_FLOCK style lock to an open file descriptor. | |
80b79dd0 | 1985 | * The @cmd can be one of: |
1da177e4 | 1986 | * |
80b79dd0 MCC |
1987 | * - %LOCK_SH -- a shared lock. |
1988 | * - %LOCK_EX -- an exclusive lock. | |
1989 | * - %LOCK_UN -- remove an existing lock. | |
1990 | * - %LOCK_MAND -- a 'mandatory' flock. | |
1991 | * This exists to emulate Windows Share Modes. | |
1da177e4 LT |
1992 | * |
1993 | * %LOCK_MAND can be combined with %LOCK_READ or %LOCK_WRITE to allow other | |
1994 | * processes read and write access respectively. | |
1995 | */ | |
002c8976 | 1996 | SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) |
1da177e4 | 1997 | { |
2903ff01 | 1998 | struct fd f = fdget(fd); |
1da177e4 LT |
1999 | struct file_lock *lock; |
2000 | int can_sleep, unlock; | |
2001 | int error; | |
2002 | ||
2003 | error = -EBADF; | |
2903ff01 | 2004 | if (!f.file) |
1da177e4 LT |
2005 | goto out; |
2006 | ||
2007 | can_sleep = !(cmd & LOCK_NB); | |
2008 | cmd &= ~LOCK_NB; | |
2009 | unlock = (cmd == LOCK_UN); | |
2010 | ||
aeb5d727 | 2011 | if (!unlock && !(cmd & LOCK_MAND) && |
2903ff01 | 2012 | !(f.file->f_mode & (FMODE_READ|FMODE_WRITE))) |
1da177e4 LT |
2013 | goto out_putf; |
2014 | ||
d6367d62 | 2015 | lock = flock_make_lock(f.file, cmd, NULL); |
6e129d00 JL |
2016 | if (IS_ERR(lock)) { |
2017 | error = PTR_ERR(lock); | |
1da177e4 | 2018 | goto out_putf; |
6e129d00 JL |
2019 | } |
2020 | ||
1da177e4 LT |
2021 | if (can_sleep) |
2022 | lock->fl_flags |= FL_SLEEP; | |
2023 | ||
2903ff01 | 2024 | error = security_file_lock(f.file, lock->fl_type); |
1da177e4 LT |
2025 | if (error) |
2026 | goto out_free; | |
2027 | ||
de2a4a50 | 2028 | if (f.file->f_op->flock) |
2903ff01 | 2029 | error = f.file->f_op->flock(f.file, |
1da177e4 LT |
2030 | (can_sleep) ? F_SETLKW : F_SETLK, |
2031 | lock); | |
2032 | else | |
4f656367 | 2033 | error = locks_lock_file_wait(f.file, lock); |
1da177e4 LT |
2034 | |
2035 | out_free: | |
993dfa87 | 2036 | locks_free_lock(lock); |
1da177e4 LT |
2037 | |
2038 | out_putf: | |
2903ff01 | 2039 | fdput(f); |
1da177e4 LT |
2040 | out: |
2041 | return error; | |
2042 | } | |
2043 | ||
3ee17abd BF |
2044 | /** |
2045 | * vfs_test_lock - test file byte range lock | |
2046 | * @filp: The file to test lock for | |
6924c554 | 2047 | * @fl: The lock to test; also used to hold result |
3ee17abd BF |
2048 | * |
2049 | * Returns -ERRNO on failure. Indicates presence of conflicting lock by | |
2050 | * setting conf->fl_type to something other than F_UNLCK. | |
2051 | */ | |
2052 | int vfs_test_lock(struct file *filp, struct file_lock *fl) | |
2053 | { | |
de2a4a50 | 2054 | if (filp->f_op->lock) |
3ee17abd BF |
2055 | return filp->f_op->lock(filp, F_GETLK, fl); |
2056 | posix_test_lock(filp, fl); | |
2057 | return 0; | |
2058 | } | |
2059 | EXPORT_SYMBOL_GPL(vfs_test_lock); | |
2060 | ||
9d5b86ac BC |
2061 | /** |
2062 | * locks_translate_pid - translate a file_lock's fl_pid number into a namespace | |
2063 | * @fl: The file_lock who's fl_pid should be translated | |
2064 | * @ns: The namespace into which the pid should be translated | |
2065 | * | |
2066 | * Used to tranlate a fl_pid into a namespace virtual pid number | |
2067 | */ | |
2068 | static pid_t locks_translate_pid(struct file_lock *fl, struct pid_namespace *ns) | |
2069 | { | |
2070 | pid_t vnr; | |
2071 | struct pid *pid; | |
2072 | ||
2073 | if (IS_OFDLCK(fl)) | |
2074 | return -1; | |
2075 | if (IS_REMOTELCK(fl)) | |
2076 | return fl->fl_pid; | |
826d7bc9 KK |
2077 | /* |
2078 | * If the flock owner process is dead and its pid has been already | |
2079 | * freed, the translation below won't work, but we still want to show | |
2080 | * flock owner pid number in init pidns. | |
2081 | */ | |
2082 | if (ns == &init_pid_ns) | |
2083 | return (pid_t)fl->fl_pid; | |
9d5b86ac BC |
2084 | |
2085 | rcu_read_lock(); | |
2086 | pid = find_pid_ns(fl->fl_pid, &init_pid_ns); | |
2087 | vnr = pid_nr_ns(pid, ns); | |
2088 | rcu_read_unlock(); | |
2089 | return vnr; | |
2090 | } | |
2091 | ||
c2fa1b8a BF |
2092 | static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl) |
2093 | { | |
9d5b86ac | 2094 | flock->l_pid = locks_translate_pid(fl, task_active_pid_ns(current)); |
c2fa1b8a BF |
2095 | #if BITS_PER_LONG == 32 |
2096 | /* | |
2097 | * Make sure we can represent the posix lock via | |
2098 | * legacy 32bit flock. | |
2099 | */ | |
2100 | if (fl->fl_start > OFFT_OFFSET_MAX) | |
2101 | return -EOVERFLOW; | |
2102 | if (fl->fl_end != OFFSET_MAX && fl->fl_end > OFFT_OFFSET_MAX) | |
2103 | return -EOVERFLOW; | |
2104 | #endif | |
2105 | flock->l_start = fl->fl_start; | |
2106 | flock->l_len = fl->fl_end == OFFSET_MAX ? 0 : | |
2107 | fl->fl_end - fl->fl_start + 1; | |
2108 | flock->l_whence = 0; | |
129a84de | 2109 | flock->l_type = fl->fl_type; |
c2fa1b8a BF |
2110 | return 0; |
2111 | } | |
2112 | ||
2113 | #if BITS_PER_LONG == 32 | |
2114 | static void posix_lock_to_flock64(struct flock64 *flock, struct file_lock *fl) | |
2115 | { | |
9d5b86ac | 2116 | flock->l_pid = locks_translate_pid(fl, task_active_pid_ns(current)); |
c2fa1b8a BF |
2117 | flock->l_start = fl->fl_start; |
2118 | flock->l_len = fl->fl_end == OFFSET_MAX ? 0 : | |
2119 | fl->fl_end - fl->fl_start + 1; | |
2120 | flock->l_whence = 0; | |
2121 | flock->l_type = fl->fl_type; | |
2122 | } | |
2123 | #endif | |
2124 | ||
1da177e4 LT |
2125 | /* Report the first existing lock that would conflict with l. |
2126 | * This implements the F_GETLK command of fcntl(). | |
2127 | */ | |
a75d30c7 | 2128 | int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock *flock) |
1da177e4 | 2129 | { |
52306e88 | 2130 | struct file_lock *fl; |
1da177e4 LT |
2131 | int error; |
2132 | ||
52306e88 BC |
2133 | fl = locks_alloc_lock(); |
2134 | if (fl == NULL) | |
2135 | return -ENOMEM; | |
1da177e4 | 2136 | error = -EINVAL; |
a75d30c7 | 2137 | if (flock->l_type != F_RDLCK && flock->l_type != F_WRLCK) |
1da177e4 LT |
2138 | goto out; |
2139 | ||
52306e88 | 2140 | error = flock_to_posix_lock(filp, fl, flock); |
1da177e4 LT |
2141 | if (error) |
2142 | goto out; | |
2143 | ||
0d3f7a2d | 2144 | if (cmd == F_OFD_GETLK) { |
90478939 | 2145 | error = -EINVAL; |
a75d30c7 | 2146 | if (flock->l_pid != 0) |
90478939 JL |
2147 | goto out; |
2148 | ||
5d50ffd7 | 2149 | cmd = F_GETLK; |
52306e88 BC |
2150 | fl->fl_flags |= FL_OFDLCK; |
2151 | fl->fl_owner = filp; | |
5d50ffd7 JL |
2152 | } |
2153 | ||
52306e88 | 2154 | error = vfs_test_lock(filp, fl); |
3ee17abd BF |
2155 | if (error) |
2156 | goto out; | |
1da177e4 | 2157 | |
52306e88 BC |
2158 | flock->l_type = fl->fl_type; |
2159 | if (fl->fl_type != F_UNLCK) { | |
2160 | error = posix_lock_to_flock(flock, fl); | |
c2fa1b8a | 2161 | if (error) |
52306e88 | 2162 | goto out; |
1da177e4 | 2163 | } |
1da177e4 | 2164 | out: |
52306e88 | 2165 | locks_free_lock(fl); |
1da177e4 LT |
2166 | return error; |
2167 | } | |
2168 | ||
7723ec97 ME |
2169 | /** |
2170 | * vfs_lock_file - file byte range lock | |
2171 | * @filp: The file to apply the lock to | |
2172 | * @cmd: type of locking operation (F_SETLK, F_GETLK, etc.) | |
2173 | * @fl: The lock to be applied | |
150b3934 ME |
2174 | * @conf: Place to return a copy of the conflicting lock, if found. |
2175 | * | |
2176 | * A caller that doesn't care about the conflicting lock may pass NULL | |
2177 | * as the final argument. | |
2178 | * | |
2179 | * If the filesystem defines a private ->lock() method, then @conf will | |
2180 | * be left unchanged; so a caller that cares should initialize it to | |
2181 | * some acceptable default. | |
2beb6614 ME |
2182 | * |
2183 | * To avoid blocking kernel daemons, such as lockd, that need to acquire POSIX | |
2184 | * locks, the ->lock() interface may return asynchronously, before the lock has | |
2185 | * been granted or denied by the underlying filesystem, if (and only if) | |
8fb47a4f | 2186 | * lm_grant is set. Callers expecting ->lock() to return asynchronously |
2beb6614 ME |
2187 | * will only use F_SETLK, not F_SETLKW; they will set FL_SLEEP if (and only if) |
2188 | * the request is for a blocking lock. When ->lock() does return asynchronously, | |
8fb47a4f | 2189 | * it must return FILE_LOCK_DEFERRED, and call ->lm_grant() when the lock |
2beb6614 ME |
2190 | * request completes. |
2191 | * If the request is for non-blocking lock the file system should return | |
bde74e4b MS |
2192 | * FILE_LOCK_DEFERRED then try to get the lock and call the callback routine |
2193 | * with the result. If the request timed out the callback routine will return a | |
2beb6614 ME |
2194 | * nonzero return code and the file system should release the lock. The file |
2195 | * system is also responsible to keep a corresponding posix lock when it | |
2196 | * grants a lock so the VFS can find out which locks are locally held and do | |
2197 | * the correct lock cleanup when required. | |
2198 | * The underlying filesystem must not drop the kernel lock or call | |
8fb47a4f | 2199 | * ->lm_grant() before returning to the caller with a FILE_LOCK_DEFERRED |
2beb6614 | 2200 | * return code. |
7723ec97 | 2201 | */ |
150b3934 | 2202 | int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, struct file_lock *conf) |
7723ec97 | 2203 | { |
de2a4a50 | 2204 | if (filp->f_op->lock) |
7723ec97 ME |
2205 | return filp->f_op->lock(filp, cmd, fl); |
2206 | else | |
150b3934 | 2207 | return posix_lock_file(filp, fl, conf); |
7723ec97 ME |
2208 | } |
2209 | EXPORT_SYMBOL_GPL(vfs_lock_file); | |
2210 | ||
b648a6de MS |
2211 | static int do_lock_file_wait(struct file *filp, unsigned int cmd, |
2212 | struct file_lock *fl) | |
2213 | { | |
2214 | int error; | |
2215 | ||
2216 | error = security_file_lock(filp, fl->fl_type); | |
2217 | if (error) | |
2218 | return error; | |
2219 | ||
764c76b3 MS |
2220 | for (;;) { |
2221 | error = vfs_lock_file(filp, cmd, fl, NULL); | |
2222 | if (error != FILE_LOCK_DEFERRED) | |
b648a6de | 2223 | break; |
ada5c1da | 2224 | error = wait_event_interruptible(fl->fl_wait, !fl->fl_blocker); |
764c76b3 MS |
2225 | if (!error) |
2226 | continue; | |
2227 | ||
2228 | locks_delete_block(fl); | |
2229 | break; | |
b648a6de MS |
2230 | } |
2231 | ||
2232 | return error; | |
2233 | } | |
2234 | ||
6ca7d910 | 2235 | /* Ensure that fl->fl_file has compatible f_mode for F_SETLK calls */ |
cf01f4ee JL |
2236 | static int |
2237 | check_fmode_for_setlk(struct file_lock *fl) | |
2238 | { | |
2239 | switch (fl->fl_type) { | |
2240 | case F_RDLCK: | |
2241 | if (!(fl->fl_file->f_mode & FMODE_READ)) | |
2242 | return -EBADF; | |
2243 | break; | |
2244 | case F_WRLCK: | |
2245 | if (!(fl->fl_file->f_mode & FMODE_WRITE)) | |
2246 | return -EBADF; | |
2247 | } | |
2248 | return 0; | |
2249 | } | |
2250 | ||
1da177e4 LT |
2251 | /* Apply the lock described by l to an open file descriptor. |
2252 | * This implements both the F_SETLK and F_SETLKW commands of fcntl(). | |
2253 | */ | |
c293621b | 2254 | int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, |
a75d30c7 | 2255 | struct flock *flock) |
1da177e4 LT |
2256 | { |
2257 | struct file_lock *file_lock = locks_alloc_lock(); | |
a75d30c7 | 2258 | struct inode *inode = locks_inode(filp); |
0b2bac2f | 2259 | struct file *f; |
1da177e4 LT |
2260 | int error; |
2261 | ||
2262 | if (file_lock == NULL) | |
2263 | return -ENOLCK; | |
2264 | ||
1da177e4 LT |
2265 | /* Don't allow mandatory locks on files that may be memory mapped |
2266 | * and shared. | |
2267 | */ | |
a16877ca | 2268 | if (mandatory_lock(inode) && mapping_writably_mapped(filp->f_mapping)) { |
1da177e4 LT |
2269 | error = -EAGAIN; |
2270 | goto out; | |
2271 | } | |
2272 | ||
a75d30c7 | 2273 | error = flock_to_posix_lock(filp, file_lock, flock); |
1da177e4 LT |
2274 | if (error) |
2275 | goto out; | |
5d50ffd7 | 2276 | |
cf01f4ee JL |
2277 | error = check_fmode_for_setlk(file_lock); |
2278 | if (error) | |
2279 | goto out; | |
2280 | ||
5d50ffd7 JL |
2281 | /* |
2282 | * If the cmd is requesting file-private locks, then set the | |
cff2fce5 | 2283 | * FL_OFDLCK flag and override the owner. |
5d50ffd7 JL |
2284 | */ |
2285 | switch (cmd) { | |
0d3f7a2d | 2286 | case F_OFD_SETLK: |
90478939 | 2287 | error = -EINVAL; |
a75d30c7 | 2288 | if (flock->l_pid != 0) |
90478939 JL |
2289 | goto out; |
2290 | ||
5d50ffd7 | 2291 | cmd = F_SETLK; |
cff2fce5 | 2292 | file_lock->fl_flags |= FL_OFDLCK; |
73a8f5f7 | 2293 | file_lock->fl_owner = filp; |
5d50ffd7 | 2294 | break; |
0d3f7a2d | 2295 | case F_OFD_SETLKW: |
90478939 | 2296 | error = -EINVAL; |
a75d30c7 | 2297 | if (flock->l_pid != 0) |
90478939 JL |
2298 | goto out; |
2299 | ||
5d50ffd7 | 2300 | cmd = F_SETLKW; |
cff2fce5 | 2301 | file_lock->fl_flags |= FL_OFDLCK; |
73a8f5f7 | 2302 | file_lock->fl_owner = filp; |
5d50ffd7 JL |
2303 | /* Fallthrough */ |
2304 | case F_SETLKW: | |
1da177e4 LT |
2305 | file_lock->fl_flags |= FL_SLEEP; |
2306 | } | |
5d50ffd7 | 2307 | |
b648a6de | 2308 | error = do_lock_file_wait(filp, cmd, file_lock); |
1da177e4 | 2309 | |
c293621b | 2310 | /* |
0752ba80 JL |
2311 | * Attempt to detect a close/fcntl race and recover by releasing the |
2312 | * lock that was just acquired. There is no need to do that when we're | |
2313 | * unlocking though, or for OFD locks. | |
c293621b | 2314 | */ |
0752ba80 JL |
2315 | if (!error && file_lock->fl_type != F_UNLCK && |
2316 | !(file_lock->fl_flags & FL_OFDLCK)) { | |
7f3697e2 JL |
2317 | /* |
2318 | * We need that spin_lock here - it prevents reordering between | |
2319 | * update of i_flctx->flc_posix and check for it done in | |
2320 | * close(). rcu_read_lock() wouldn't do. | |
2321 | */ | |
2322 | spin_lock(¤t->files->file_lock); | |
2323 | f = fcheck(fd); | |
2324 | spin_unlock(¤t->files->file_lock); | |
2325 | if (f != filp) { | |
2326 | file_lock->fl_type = F_UNLCK; | |
2327 | error = do_lock_file_wait(filp, cmd, file_lock); | |
2328 | WARN_ON_ONCE(error); | |
2329 | error = -EBADF; | |
2330 | } | |
1da177e4 | 2331 | } |
c293621b | 2332 | out: |
1890910f | 2333 | trace_fcntl_setlk(inode, file_lock, error); |
1da177e4 LT |
2334 | locks_free_lock(file_lock); |
2335 | return error; | |
2336 | } | |
2337 | ||
2338 | #if BITS_PER_LONG == 32 | |
2339 | /* Report the first existing lock that would conflict with l. | |
2340 | * This implements the F_GETLK command of fcntl(). | |
2341 | */ | |
a75d30c7 | 2342 | int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 *flock) |
1da177e4 | 2343 | { |
52306e88 | 2344 | struct file_lock *fl; |
1da177e4 LT |
2345 | int error; |
2346 | ||
52306e88 BC |
2347 | fl = locks_alloc_lock(); |
2348 | if (fl == NULL) | |
2349 | return -ENOMEM; | |
2350 | ||
1da177e4 | 2351 | error = -EINVAL; |
a75d30c7 | 2352 | if (flock->l_type != F_RDLCK && flock->l_type != F_WRLCK) |
1da177e4 LT |
2353 | goto out; |
2354 | ||
52306e88 | 2355 | error = flock64_to_posix_lock(filp, fl, flock); |
1da177e4 LT |
2356 | if (error) |
2357 | goto out; | |
2358 | ||
0d3f7a2d | 2359 | if (cmd == F_OFD_GETLK) { |
90478939 | 2360 | error = -EINVAL; |
a75d30c7 | 2361 | if (flock->l_pid != 0) |
90478939 JL |
2362 | goto out; |
2363 | ||
5d50ffd7 | 2364 | cmd = F_GETLK64; |
52306e88 BC |
2365 | fl->fl_flags |= FL_OFDLCK; |
2366 | fl->fl_owner = filp; | |
5d50ffd7 JL |
2367 | } |
2368 | ||
52306e88 | 2369 | error = vfs_test_lock(filp, fl); |
3ee17abd BF |
2370 | if (error) |
2371 | goto out; | |
2372 | ||
52306e88 BC |
2373 | flock->l_type = fl->fl_type; |
2374 | if (fl->fl_type != F_UNLCK) | |
2375 | posix_lock_to_flock64(flock, fl); | |
f328296e | 2376 | |
1da177e4 | 2377 | out: |
52306e88 | 2378 | locks_free_lock(fl); |
1da177e4 LT |
2379 | return error; |
2380 | } | |
2381 | ||
2382 | /* Apply the lock described by l to an open file descriptor. | |
2383 | * This implements both the F_SETLK and F_SETLKW commands of fcntl(). | |
2384 | */ | |
c293621b | 2385 | int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd, |
a75d30c7 | 2386 | struct flock64 *flock) |
1da177e4 LT |
2387 | { |
2388 | struct file_lock *file_lock = locks_alloc_lock(); | |
a75d30c7 | 2389 | struct inode *inode = locks_inode(filp); |
0b2bac2f | 2390 | struct file *f; |
1da177e4 LT |
2391 | int error; |
2392 | ||
2393 | if (file_lock == NULL) | |
2394 | return -ENOLCK; | |
2395 | ||
1da177e4 LT |
2396 | /* Don't allow mandatory locks on files that may be memory mapped |
2397 | * and shared. | |
2398 | */ | |
a16877ca | 2399 | if (mandatory_lock(inode) && mapping_writably_mapped(filp->f_mapping)) { |
1da177e4 LT |
2400 | error = -EAGAIN; |
2401 | goto out; | |
2402 | } | |
2403 | ||
a75d30c7 | 2404 | error = flock64_to_posix_lock(filp, file_lock, flock); |
1da177e4 LT |
2405 | if (error) |
2406 | goto out; | |
5d50ffd7 | 2407 | |
cf01f4ee JL |
2408 | error = check_fmode_for_setlk(file_lock); |
2409 | if (error) | |
2410 | goto out; | |
2411 | ||
5d50ffd7 JL |
2412 | /* |
2413 | * If the cmd is requesting file-private locks, then set the | |
cff2fce5 | 2414 | * FL_OFDLCK flag and override the owner. |
5d50ffd7 JL |
2415 | */ |
2416 | switch (cmd) { | |
0d3f7a2d | 2417 | case F_OFD_SETLK: |
90478939 | 2418 | error = -EINVAL; |
a75d30c7 | 2419 | if (flock->l_pid != 0) |
90478939 JL |
2420 | goto out; |
2421 | ||
5d50ffd7 | 2422 | cmd = F_SETLK64; |
cff2fce5 | 2423 | file_lock->fl_flags |= FL_OFDLCK; |
73a8f5f7 | 2424 | file_lock->fl_owner = filp; |
5d50ffd7 | 2425 | break; |
0d3f7a2d | 2426 | case F_OFD_SETLKW: |
90478939 | 2427 | error = -EINVAL; |
a75d30c7 | 2428 | if (flock->l_pid != 0) |
90478939 JL |
2429 | goto out; |
2430 | ||
5d50ffd7 | 2431 | cmd = F_SETLKW64; |
cff2fce5 | 2432 | file_lock->fl_flags |= FL_OFDLCK; |
73a8f5f7 | 2433 | file_lock->fl_owner = filp; |
5d50ffd7 JL |
2434 | /* Fallthrough */ |
2435 | case F_SETLKW64: | |
1da177e4 LT |
2436 | file_lock->fl_flags |= FL_SLEEP; |
2437 | } | |
5d50ffd7 | 2438 | |
b648a6de | 2439 | error = do_lock_file_wait(filp, cmd, file_lock); |
1da177e4 | 2440 | |
c293621b | 2441 | /* |
0752ba80 JL |
2442 | * Attempt to detect a close/fcntl race and recover by releasing the |
2443 | * lock that was just acquired. There is no need to do that when we're | |
2444 | * unlocking though, or for OFD locks. | |
c293621b | 2445 | */ |
0752ba80 JL |
2446 | if (!error && file_lock->fl_type != F_UNLCK && |
2447 | !(file_lock->fl_flags & FL_OFDLCK)) { | |
7f3697e2 JL |
2448 | /* |
2449 | * We need that spin_lock here - it prevents reordering between | |
2450 | * update of i_flctx->flc_posix and check for it done in | |
2451 | * close(). rcu_read_lock() wouldn't do. | |
2452 | */ | |
2453 | spin_lock(¤t->files->file_lock); | |
2454 | f = fcheck(fd); | |
2455 | spin_unlock(¤t->files->file_lock); | |
2456 | if (f != filp) { | |
2457 | file_lock->fl_type = F_UNLCK; | |
2458 | error = do_lock_file_wait(filp, cmd, file_lock); | |
2459 | WARN_ON_ONCE(error); | |
2460 | error = -EBADF; | |
2461 | } | |
1da177e4 | 2462 | } |
1da177e4 LT |
2463 | out: |
2464 | locks_free_lock(file_lock); | |
2465 | return error; | |
2466 | } | |
2467 | #endif /* BITS_PER_LONG == 32 */ | |
2468 | ||
2469 | /* | |
2470 | * This function is called when the file is being removed | |
2471 | * from the task's fd array. POSIX locks belonging to this task | |
2472 | * are deleted at this time. | |
2473 | */ | |
2474 | void locks_remove_posix(struct file *filp, fl_owner_t owner) | |
2475 | { | |
1890910f | 2476 | int error; |
c568d683 | 2477 | struct inode *inode = locks_inode(filp); |
ff7b86b8 | 2478 | struct file_lock lock; |
128a3785 | 2479 | struct file_lock_context *ctx; |
1da177e4 LT |
2480 | |
2481 | /* | |
2482 | * If there are no locks held on this file, we don't need to call | |
2483 | * posix_lock_file(). Another process could be setting a lock on this | |
2484 | * file at the same time, but we wouldn't remove that lock anyway. | |
2485 | */ | |
c568d683 | 2486 | ctx = smp_load_acquire(&inode->i_flctx); |
bd61e0a9 | 2487 | if (!ctx || list_empty(&ctx->flc_posix)) |
1da177e4 LT |
2488 | return; |
2489 | ||
d6367d62 | 2490 | locks_init_lock(&lock); |
1da177e4 | 2491 | lock.fl_type = F_UNLCK; |
75e1fcc0 | 2492 | lock.fl_flags = FL_POSIX | FL_CLOSE; |
1da177e4 LT |
2493 | lock.fl_start = 0; |
2494 | lock.fl_end = OFFSET_MAX; | |
2495 | lock.fl_owner = owner; | |
2496 | lock.fl_pid = current->tgid; | |
2497 | lock.fl_file = filp; | |
2498 | lock.fl_ops = NULL; | |
2499 | lock.fl_lmops = NULL; | |
2500 | ||
1890910f | 2501 | error = vfs_lock_file(filp, F_SETLK, &lock, NULL); |
1da177e4 | 2502 | |
1da177e4 LT |
2503 | if (lock.fl_ops && lock.fl_ops->fl_release_private) |
2504 | lock.fl_ops->fl_release_private(&lock); | |
c568d683 | 2505 | trace_locks_remove_posix(inode, &lock, error); |
1da177e4 LT |
2506 | } |
2507 | ||
2508 | EXPORT_SYMBOL(locks_remove_posix); | |
2509 | ||
3d8e560d | 2510 | /* The i_flctx must be valid when calling into here */ |
dd459bb1 | 2511 | static void |
128a3785 | 2512 | locks_remove_flock(struct file *filp, struct file_lock_context *flctx) |
dd459bb1 | 2513 | { |
d6367d62 | 2514 | struct file_lock fl; |
c568d683 | 2515 | struct inode *inode = locks_inode(filp); |
dd459bb1 | 2516 | |
3d8e560d | 2517 | if (list_empty(&flctx->flc_flock)) |
dd459bb1 JL |
2518 | return; |
2519 | ||
d6367d62 N |
2520 | flock_make_lock(filp, LOCK_UN, &fl); |
2521 | fl.fl_flags |= FL_CLOSE; | |
2522 | ||
de2a4a50 | 2523 | if (filp->f_op->flock) |
dd459bb1 JL |
2524 | filp->f_op->flock(filp, F_SETLKW, &fl); |
2525 | else | |
bcd7f78d | 2526 | flock_lock_inode(inode, &fl); |
dd459bb1 JL |
2527 | |
2528 | if (fl.fl_ops && fl.fl_ops->fl_release_private) | |
2529 | fl.fl_ops->fl_release_private(&fl); | |
2530 | } | |
2531 | ||
3d8e560d | 2532 | /* The i_flctx must be valid when calling into here */ |
8634b51f | 2533 | static void |
128a3785 | 2534 | locks_remove_lease(struct file *filp, struct file_lock_context *ctx) |
8634b51f | 2535 | { |
8634b51f JL |
2536 | struct file_lock *fl, *tmp; |
2537 | LIST_HEAD(dispose); | |
2538 | ||
3d8e560d | 2539 | if (list_empty(&ctx->flc_lease)) |
8634b51f JL |
2540 | return; |
2541 | ||
5f43086b | 2542 | percpu_down_read_preempt_disable(&file_rwsem); |
6109c850 | 2543 | spin_lock(&ctx->flc_lock); |
8634b51f | 2544 | list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list) |
c4e136cd JL |
2545 | if (filp == fl->fl_file) |
2546 | lease_modify(fl, F_UNLCK, &dispose); | |
6109c850 | 2547 | spin_unlock(&ctx->flc_lock); |
5f43086b PZ |
2548 | percpu_up_read_preempt_enable(&file_rwsem); |
2549 | ||
8634b51f JL |
2550 | locks_dispose_list(&dispose); |
2551 | } | |
2552 | ||
1da177e4 LT |
2553 | /* |
2554 | * This function is called on the last close of an open file. | |
2555 | */ | |
78ed8a13 | 2556 | void locks_remove_file(struct file *filp) |
1da177e4 | 2557 | { |
128a3785 DV |
2558 | struct file_lock_context *ctx; |
2559 | ||
c568d683 | 2560 | ctx = smp_load_acquire(&locks_inode(filp)->i_flctx); |
128a3785 | 2561 | if (!ctx) |
3d8e560d JL |
2562 | return; |
2563 | ||
dd459bb1 | 2564 | /* remove any OFD locks */ |
73a8f5f7 | 2565 | locks_remove_posix(filp, filp); |
5d50ffd7 | 2566 | |
dd459bb1 | 2567 | /* remove flock locks */ |
128a3785 | 2568 | locks_remove_flock(filp, ctx); |
dd459bb1 | 2569 | |
8634b51f | 2570 | /* remove any leases */ |
128a3785 | 2571 | locks_remove_lease(filp, ctx); |
3953704f BC |
2572 | |
2573 | spin_lock(&ctx->flc_lock); | |
2574 | locks_check_ctx_file_list(filp, &ctx->flc_posix, "POSIX"); | |
2575 | locks_check_ctx_file_list(filp, &ctx->flc_flock, "FLOCK"); | |
2576 | locks_check_ctx_file_list(filp, &ctx->flc_lease, "LEASE"); | |
2577 | spin_unlock(&ctx->flc_lock); | |
1da177e4 LT |
2578 | } |
2579 | ||
1da177e4 LT |
2580 | /** |
2581 | * posix_unblock_lock - stop waiting for a file lock | |
1da177e4 LT |
2582 | * @waiter: the lock which was waiting |
2583 | * | |
2584 | * lockd needs to block waiting for locks. | |
2585 | */ | |
64a318ee | 2586 | int |
f891a29f | 2587 | posix_unblock_lock(struct file_lock *waiter) |
1da177e4 | 2588 | { |
64a318ee BF |
2589 | int status = 0; |
2590 | ||
7b2296af | 2591 | spin_lock(&blocked_lock_lock); |
ada5c1da | 2592 | if (waiter->fl_blocker) |
1da177e4 | 2593 | __locks_delete_block(waiter); |
64a318ee BF |
2594 | else |
2595 | status = -ENOENT; | |
7b2296af | 2596 | spin_unlock(&blocked_lock_lock); |
64a318ee | 2597 | return status; |
1da177e4 | 2598 | } |
1da177e4 LT |
2599 | EXPORT_SYMBOL(posix_unblock_lock); |
2600 | ||
9b9d2ab4 ME |
2601 | /** |
2602 | * vfs_cancel_lock - file byte range unblock lock | |
2603 | * @filp: The file to apply the unblock to | |
2604 | * @fl: The lock to be unblocked | |
2605 | * | |
2606 | * Used by lock managers to cancel blocked requests | |
2607 | */ | |
2608 | int vfs_cancel_lock(struct file *filp, struct file_lock *fl) | |
2609 | { | |
de2a4a50 | 2610 | if (filp->f_op->lock) |
9b9d2ab4 ME |
2611 | return filp->f_op->lock(filp, F_CANCELLK, fl); |
2612 | return 0; | |
2613 | } | |
2614 | ||
2615 | EXPORT_SYMBOL_GPL(vfs_cancel_lock); | |
2616 | ||
7f8ada98 | 2617 | #ifdef CONFIG_PROC_FS |
d8ba7a36 | 2618 | #include <linux/proc_fs.h> |
7f8ada98 PE |
2619 | #include <linux/seq_file.h> |
2620 | ||
7012b02a JL |
2621 | struct locks_iterator { |
2622 | int li_cpu; | |
2623 | loff_t li_pos; | |
2624 | }; | |
2625 | ||
7f8ada98 | 2626 | static void lock_get_status(struct seq_file *f, struct file_lock *fl, |
99dc8292 | 2627 | loff_t id, char *pfx) |
1da177e4 LT |
2628 | { |
2629 | struct inode *inode = NULL; | |
ab1f1611 | 2630 | unsigned int fl_pid; |
9d5b86ac | 2631 | struct pid_namespace *proc_pidns = file_inode(f->file)->i_sb->s_fs_info; |
ab1f1611 | 2632 | |
9d5b86ac BC |
2633 | fl_pid = locks_translate_pid(fl, proc_pidns); |
2634 | /* | |
1cf8e5de KK |
2635 | * If lock owner is dead (and pid is freed) or not visible in current |
2636 | * pidns, zero is shown as a pid value. Check lock info from | |
2637 | * init_pid_ns to get saved lock pid value. | |
9d5b86ac | 2638 | */ |
1da177e4 LT |
2639 | |
2640 | if (fl->fl_file != NULL) | |
c568d683 | 2641 | inode = locks_inode(fl->fl_file); |
1da177e4 | 2642 | |
99dc8292 | 2643 | seq_printf(f, "%lld:%s ", id, pfx); |
1da177e4 | 2644 | if (IS_POSIX(fl)) { |
c918d42a | 2645 | if (fl->fl_flags & FL_ACCESS) |
5315c26a | 2646 | seq_puts(f, "ACCESS"); |
cff2fce5 | 2647 | else if (IS_OFDLCK(fl)) |
5315c26a | 2648 | seq_puts(f, "OFDLCK"); |
c918d42a | 2649 | else |
5315c26a | 2650 | seq_puts(f, "POSIX "); |
c918d42a JL |
2651 | |
2652 | seq_printf(f, " %s ", | |
1da177e4 | 2653 | (inode == NULL) ? "*NOINODE*" : |
a16877ca | 2654 | mandatory_lock(inode) ? "MANDATORY" : "ADVISORY "); |
1da177e4 LT |
2655 | } else if (IS_FLOCK(fl)) { |
2656 | if (fl->fl_type & LOCK_MAND) { | |
5315c26a | 2657 | seq_puts(f, "FLOCK MSNFS "); |
1da177e4 | 2658 | } else { |
5315c26a | 2659 | seq_puts(f, "FLOCK ADVISORY "); |
1da177e4 LT |
2660 | } |
2661 | } else if (IS_LEASE(fl)) { | |
8144f1f6 JL |
2662 | if (fl->fl_flags & FL_DELEG) |
2663 | seq_puts(f, "DELEG "); | |
2664 | else | |
2665 | seq_puts(f, "LEASE "); | |
2666 | ||
ab83fa4b | 2667 | if (lease_breaking(fl)) |
5315c26a | 2668 | seq_puts(f, "BREAKING "); |
1da177e4 | 2669 | else if (fl->fl_file) |
5315c26a | 2670 | seq_puts(f, "ACTIVE "); |
1da177e4 | 2671 | else |
5315c26a | 2672 | seq_puts(f, "BREAKER "); |
1da177e4 | 2673 | } else { |
5315c26a | 2674 | seq_puts(f, "UNKNOWN UNKNOWN "); |
1da177e4 LT |
2675 | } |
2676 | if (fl->fl_type & LOCK_MAND) { | |
7f8ada98 | 2677 | seq_printf(f, "%s ", |
1da177e4 LT |
2678 | (fl->fl_type & LOCK_READ) |
2679 | ? (fl->fl_type & LOCK_WRITE) ? "RW " : "READ " | |
2680 | : (fl->fl_type & LOCK_WRITE) ? "WRITE" : "NONE "); | |
2681 | } else { | |
7f8ada98 | 2682 | seq_printf(f, "%s ", |
ab83fa4b | 2683 | (lease_breaking(fl)) |
0ee5c6d6 JL |
2684 | ? (fl->fl_type == F_UNLCK) ? "UNLCK" : "READ " |
2685 | : (fl->fl_type == F_WRLCK) ? "WRITE" : "READ "); | |
1da177e4 LT |
2686 | } |
2687 | if (inode) { | |
3648888e | 2688 | /* userspace relies on this representation of dev_t */ |
ab1f1611 | 2689 | seq_printf(f, "%d %02x:%02x:%ld ", fl_pid, |
1da177e4 LT |
2690 | MAJOR(inode->i_sb->s_dev), |
2691 | MINOR(inode->i_sb->s_dev), inode->i_ino); | |
1da177e4 | 2692 | } else { |
ab1f1611 | 2693 | seq_printf(f, "%d <none>:0 ", fl_pid); |
1da177e4 LT |
2694 | } |
2695 | if (IS_POSIX(fl)) { | |
2696 | if (fl->fl_end == OFFSET_MAX) | |
7f8ada98 | 2697 | seq_printf(f, "%Ld EOF\n", fl->fl_start); |
1da177e4 | 2698 | else |
7f8ada98 | 2699 | seq_printf(f, "%Ld %Ld\n", fl->fl_start, fl->fl_end); |
1da177e4 | 2700 | } else { |
5315c26a | 2701 | seq_puts(f, "0 EOF\n"); |
1da177e4 LT |
2702 | } |
2703 | } | |
2704 | ||
7f8ada98 | 2705 | static int locks_show(struct seq_file *f, void *v) |
1da177e4 | 2706 | { |
7012b02a | 2707 | struct locks_iterator *iter = f->private; |
7f8ada98 | 2708 | struct file_lock *fl, *bfl; |
d67fd44f | 2709 | struct pid_namespace *proc_pidns = file_inode(f->file)->i_sb->s_fs_info; |
1da177e4 | 2710 | |
139ca04e | 2711 | fl = hlist_entry(v, struct file_lock, fl_link); |
1da177e4 | 2712 | |
9d5b86ac | 2713 | if (locks_translate_pid(fl, proc_pidns) == 0) |
d67fd44f NB |
2714 | return 0; |
2715 | ||
7012b02a | 2716 | lock_get_status(f, fl, iter->li_pos, ""); |
1da177e4 | 2717 | |
ada5c1da | 2718 | list_for_each_entry(bfl, &fl->fl_blocked_requests, fl_blocked_member) |
7012b02a | 2719 | lock_get_status(f, bfl, iter->li_pos, " ->"); |
094f2825 | 2720 | |
7f8ada98 PE |
2721 | return 0; |
2722 | } | |
1da177e4 | 2723 | |
6c8c9031 AV |
2724 | static void __show_fd_locks(struct seq_file *f, |
2725 | struct list_head *head, int *id, | |
2726 | struct file *filp, struct files_struct *files) | |
2727 | { | |
2728 | struct file_lock *fl; | |
2729 | ||
2730 | list_for_each_entry(fl, head, fl_list) { | |
2731 | ||
2732 | if (filp != fl->fl_file) | |
2733 | continue; | |
2734 | if (fl->fl_owner != files && | |
2735 | fl->fl_owner != filp) | |
2736 | continue; | |
2737 | ||
2738 | (*id)++; | |
2739 | seq_puts(f, "lock:\t"); | |
2740 | lock_get_status(f, fl, *id, ""); | |
2741 | } | |
2742 | } | |
2743 | ||
2744 | void show_fd_locks(struct seq_file *f, | |
2745 | struct file *filp, struct files_struct *files) | |
2746 | { | |
c568d683 | 2747 | struct inode *inode = locks_inode(filp); |
6c8c9031 AV |
2748 | struct file_lock_context *ctx; |
2749 | int id = 0; | |
2750 | ||
128a3785 | 2751 | ctx = smp_load_acquire(&inode->i_flctx); |
6c8c9031 AV |
2752 | if (!ctx) |
2753 | return; | |
2754 | ||
2755 | spin_lock(&ctx->flc_lock); | |
2756 | __show_fd_locks(f, &ctx->flc_flock, &id, filp, files); | |
2757 | __show_fd_locks(f, &ctx->flc_posix, &id, filp, files); | |
2758 | __show_fd_locks(f, &ctx->flc_lease, &id, filp, files); | |
2759 | spin_unlock(&ctx->flc_lock); | |
2760 | } | |
2761 | ||
7f8ada98 | 2762 | static void *locks_start(struct seq_file *f, loff_t *pos) |
b03dfdec | 2763 | __acquires(&blocked_lock_lock) |
7f8ada98 | 2764 | { |
7012b02a | 2765 | struct locks_iterator *iter = f->private; |
99dc8292 | 2766 | |
7012b02a | 2767 | iter->li_pos = *pos + 1; |
aba37660 | 2768 | percpu_down_write(&file_rwsem); |
7b2296af | 2769 | spin_lock(&blocked_lock_lock); |
7c3f654d | 2770 | return seq_hlist_start_percpu(&file_lock_list.hlist, &iter->li_cpu, *pos); |
7f8ada98 | 2771 | } |
1da177e4 | 2772 | |
7f8ada98 PE |
2773 | static void *locks_next(struct seq_file *f, void *v, loff_t *pos) |
2774 | { | |
7012b02a JL |
2775 | struct locks_iterator *iter = f->private; |
2776 | ||
2777 | ++iter->li_pos; | |
7c3f654d | 2778 | return seq_hlist_next_percpu(v, &file_lock_list.hlist, &iter->li_cpu, pos); |
7f8ada98 | 2779 | } |
1da177e4 | 2780 | |
7f8ada98 | 2781 | static void locks_stop(struct seq_file *f, void *v) |
b03dfdec | 2782 | __releases(&blocked_lock_lock) |
7f8ada98 | 2783 | { |
7b2296af | 2784 | spin_unlock(&blocked_lock_lock); |
aba37660 | 2785 | percpu_up_write(&file_rwsem); |
1da177e4 LT |
2786 | } |
2787 | ||
d8ba7a36 | 2788 | static const struct seq_operations locks_seq_operations = { |
7f8ada98 PE |
2789 | .start = locks_start, |
2790 | .next = locks_next, | |
2791 | .stop = locks_stop, | |
2792 | .show = locks_show, | |
2793 | }; | |
d8ba7a36 | 2794 | |
d8ba7a36 AD |
2795 | static int __init proc_locks_init(void) |
2796 | { | |
44414d82 CH |
2797 | proc_create_seq_private("locks", 0, NULL, &locks_seq_operations, |
2798 | sizeof(struct locks_iterator), NULL); | |
d8ba7a36 AD |
2799 | return 0; |
2800 | } | |
91899226 | 2801 | fs_initcall(proc_locks_init); |
7f8ada98 PE |
2802 | #endif |
2803 | ||
1da177e4 LT |
2804 | static int __init filelock_init(void) |
2805 | { | |
7012b02a JL |
2806 | int i; |
2807 | ||
4a075e39 JL |
2808 | flctx_cache = kmem_cache_create("file_lock_ctx", |
2809 | sizeof(struct file_lock_context), 0, SLAB_PANIC, NULL); | |
2810 | ||
1da177e4 | 2811 | filelock_cache = kmem_cache_create("file_lock_cache", |
ee19cc40 MS |
2812 | sizeof(struct file_lock), 0, SLAB_PANIC, NULL); |
2813 | ||
7012b02a | 2814 | |
7c3f654d PZ |
2815 | for_each_possible_cpu(i) { |
2816 | struct file_lock_list_struct *fll = per_cpu_ptr(&file_lock_list, i); | |
2817 | ||
2818 | spin_lock_init(&fll->lock); | |
2819 | INIT_HLIST_HEAD(&fll->hlist); | |
2820 | } | |
7012b02a | 2821 | |
1da177e4 LT |
2822 | return 0; |
2823 | } | |
2824 | ||
2825 | core_initcall(filelock_init); |