1 /* AFS file locking support
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
14 #define AFS_LOCK_GRANTED 0
15 #define AFS_LOCK_PENDING 1
16 #define AFS_LOCK_YOUR_TRY 2
18 struct workqueue_struct
*afs_lock_manager
;
20 static void afs_next_locker(struct afs_vnode
*vnode
, int error
);
21 static void afs_fl_copy_lock(struct file_lock
*new, struct file_lock
*fl
);
22 static void afs_fl_release_private(struct file_lock
*fl
);
24 static const struct file_lock_operations afs_lock_ops
= {
25 .fl_copy_lock
= afs_fl_copy_lock
,
26 .fl_release_private
= afs_fl_release_private
,
29 static inline void afs_set_lock_state(struct afs_vnode
*vnode
, enum afs_lock_state state
)
31 _debug("STATE %u -> %u", vnode
->lock_state
, state
);
32 vnode
->lock_state
= state
;
35 static atomic_t afs_file_lock_debug_id
;
38 * if the callback is broken on this vnode, then the lock may now be available
40 void afs_lock_may_be_available(struct afs_vnode
*vnode
)
42 _enter("{%llx:%llu}", vnode
->fid
.vid
, vnode
->fid
.vnode
);
44 spin_lock(&vnode
->lock
);
45 if (vnode
->lock_state
== AFS_VNODE_LOCK_WAITING_FOR_CB
)
46 afs_next_locker(vnode
, 0);
47 trace_afs_flock_ev(vnode
, NULL
, afs_flock_callback_break
, 0);
48 spin_unlock(&vnode
->lock
);
52 * the lock will time out in 5 minutes unless we extend it, so schedule
53 * extension in a bit less than that time
55 static void afs_schedule_lock_extension(struct afs_vnode
*vnode
)
57 ktime_t expires_at
, now
, duration
;
60 expires_at
= ktime_add_ms(vnode
->locked_at
, AFS_LOCKWAIT
* 1000 / 2);
61 now
= ktime_get_real();
62 duration
= ktime_sub(expires_at
, now
);
66 duration_j
= nsecs_to_jiffies(ktime_to_ns(duration
));
68 queue_delayed_work(afs_lock_manager
, &vnode
->lock_work
, duration_j
);
72 * In the case of successful completion of a lock operation, record the time
73 * the reply appeared and start the lock extension timer.
75 void afs_lock_op_done(struct afs_call
*call
)
77 struct afs_vnode
*vnode
= call
->lvnode
;
79 if (call
->error
== 0) {
80 spin_lock(&vnode
->lock
);
81 trace_afs_flock_ev(vnode
, NULL
, afs_flock_timestamp
, 0);
82 vnode
->locked_at
= call
->reply_time
;
83 afs_schedule_lock_extension(vnode
);
84 spin_unlock(&vnode
->lock
);
89 * grant one or more locks (readlocks are allowed to jump the queue if the
90 * first lock in the queue is itself a readlock)
91 * - the caller must hold the vnode lock
93 static void afs_grant_locks(struct afs_vnode
*vnode
)
95 struct file_lock
*p
, *_p
;
96 bool exclusive
= (vnode
->lock_type
== AFS_LOCK_WRITE
);
98 list_for_each_entry_safe(p
, _p
, &vnode
->pending_locks
, fl_u
.afs
.link
) {
99 if (!exclusive
&& p
->fl_type
== F_WRLCK
)
102 list_move_tail(&p
->fl_u
.afs
.link
, &vnode
->granted_locks
);
103 p
->fl_u
.afs
.state
= AFS_LOCK_GRANTED
;
104 trace_afs_flock_op(vnode
, p
, afs_flock_op_grant
);
105 wake_up(&p
->fl_wait
);
110 * If an error is specified, reject every pending lock that matches the
111 * authentication and type of the lock we failed to get. If there are any
112 * remaining lockers, try to wake up one of them to have a go.
114 static void afs_next_locker(struct afs_vnode
*vnode
, int error
)
116 struct file_lock
*p
, *_p
, *next
= NULL
;
117 struct key
*key
= vnode
->lock_key
;
118 unsigned int fl_type
= F_RDLCK
;
122 if (vnode
->lock_type
== AFS_LOCK_WRITE
)
125 list_for_each_entry_safe(p
, _p
, &vnode
->pending_locks
, fl_u
.afs
.link
) {
127 p
->fl_type
== fl_type
&&
128 afs_file_key(p
->fl_file
) == key
) {
129 list_del_init(&p
->fl_u
.afs
.link
);
130 p
->fl_u
.afs
.state
= error
;
131 wake_up(&p
->fl_wait
);
134 /* Select the next locker to hand off to. */
136 (next
->fl_type
== F_WRLCK
|| p
->fl_type
== F_RDLCK
))
141 vnode
->lock_key
= NULL
;
145 afs_set_lock_state(vnode
, AFS_VNODE_LOCK_SETTING
);
146 next
->fl_u
.afs
.state
= AFS_LOCK_YOUR_TRY
;
147 trace_afs_flock_op(vnode
, next
, afs_flock_op_wake
);
148 wake_up(&next
->fl_wait
);
150 afs_set_lock_state(vnode
, AFS_VNODE_LOCK_NONE
);
151 trace_afs_flock_ev(vnode
, NULL
, afs_flock_no_lockers
, 0);
158 * Kill off all waiters in the the pending lock queue due to the vnode being
161 static void afs_kill_lockers_enoent(struct afs_vnode
*vnode
)
165 afs_set_lock_state(vnode
, AFS_VNODE_LOCK_DELETED
);
167 while (!list_empty(&vnode
->pending_locks
)) {
168 p
= list_entry(vnode
->pending_locks
.next
,
169 struct file_lock
, fl_u
.afs
.link
);
170 list_del_init(&p
->fl_u
.afs
.link
);
171 p
->fl_u
.afs
.state
= -ENOENT
;
172 wake_up(&p
->fl_wait
);
175 key_put(vnode
->lock_key
);
176 vnode
->lock_key
= NULL
;
180 * Get a lock on a file
182 static int afs_set_lock(struct afs_vnode
*vnode
, struct key
*key
,
183 afs_lock_type_t type
)
185 struct afs_status_cb
*scb
;
186 struct afs_fs_cursor fc
;
189 _enter("%s{%llx:%llu.%u},%x,%u",
194 key_serial(key
), type
);
196 scb
= kzalloc(sizeof(struct afs_status_cb
), GFP_KERNEL
);
201 if (afs_begin_vnode_operation(&fc
, vnode
, key
, true)) {
202 while (afs_select_fileserver(&fc
)) {
203 fc
.cb_break
= afs_calc_vnode_cb_break(vnode
);
204 afs_fs_set_lock(&fc
, type
, scb
);
207 afs_check_for_remote_deletion(&fc
, vnode
);
208 afs_vnode_commit_status(&fc
, vnode
, fc
.cb_break
, NULL
, scb
);
209 ret
= afs_end_vnode_operation(&fc
);
213 _leave(" = %d", ret
);
218 * Extend a lock on a file
220 static int afs_extend_lock(struct afs_vnode
*vnode
, struct key
*key
)
222 struct afs_status_cb
*scb
;
223 struct afs_fs_cursor fc
;
226 _enter("%s{%llx:%llu.%u},%x",
233 scb
= kzalloc(sizeof(struct afs_status_cb
), GFP_KERNEL
);
238 if (afs_begin_vnode_operation(&fc
, vnode
, key
, false)) {
239 while (afs_select_current_fileserver(&fc
)) {
240 fc
.cb_break
= afs_calc_vnode_cb_break(vnode
);
241 afs_fs_extend_lock(&fc
, scb
);
244 afs_check_for_remote_deletion(&fc
, vnode
);
245 afs_vnode_commit_status(&fc
, vnode
, fc
.cb_break
, NULL
, scb
);
246 ret
= afs_end_vnode_operation(&fc
);
250 _leave(" = %d", ret
);
255 * Release a lock on a file
257 static int afs_release_lock(struct afs_vnode
*vnode
, struct key
*key
)
259 struct afs_status_cb
*scb
;
260 struct afs_fs_cursor fc
;
263 _enter("%s{%llx:%llu.%u},%x",
270 scb
= kzalloc(sizeof(struct afs_status_cb
), GFP_KERNEL
);
275 if (afs_begin_vnode_operation(&fc
, vnode
, key
, false)) {
276 while (afs_select_current_fileserver(&fc
)) {
277 fc
.cb_break
= afs_calc_vnode_cb_break(vnode
);
278 afs_fs_release_lock(&fc
, scb
);
281 afs_check_for_remote_deletion(&fc
, vnode
);
282 afs_vnode_commit_status(&fc
, vnode
, fc
.cb_break
, NULL
, scb
);
283 ret
= afs_end_vnode_operation(&fc
);
287 _leave(" = %d", ret
);
292 * do work for a lock, including:
293 * - probing for a lock we're waiting on but didn't get immediately
294 * - extending a lock that's close to timing out
296 void afs_lock_work(struct work_struct
*work
)
298 struct afs_vnode
*vnode
=
299 container_of(work
, struct afs_vnode
, lock_work
.work
);
303 _enter("{%llx:%llu}", vnode
->fid
.vid
, vnode
->fid
.vnode
);
305 spin_lock(&vnode
->lock
);
308 _debug("wstate %u for %p", vnode
->lock_state
, vnode
);
309 switch (vnode
->lock_state
) {
310 case AFS_VNODE_LOCK_NEED_UNLOCK
:
311 afs_set_lock_state(vnode
, AFS_VNODE_LOCK_UNLOCKING
);
312 trace_afs_flock_ev(vnode
, NULL
, afs_flock_work_unlocking
, 0);
313 spin_unlock(&vnode
->lock
);
315 /* attempt to release the server lock; if it fails, we just
316 * wait 5 minutes and it'll expire anyway */
317 ret
= afs_release_lock(vnode
, vnode
->lock_key
);
318 if (ret
< 0 && vnode
->lock_state
!= AFS_VNODE_LOCK_DELETED
) {
319 trace_afs_flock_ev(vnode
, NULL
, afs_flock_release_fail
,
321 printk(KERN_WARNING
"AFS:"
322 " Failed to release lock on {%llx:%llx} error %d\n",
323 vnode
->fid
.vid
, vnode
->fid
.vnode
, ret
);
326 spin_lock(&vnode
->lock
);
328 afs_kill_lockers_enoent(vnode
);
330 afs_next_locker(vnode
, 0);
331 spin_unlock(&vnode
->lock
);
334 /* If we've already got a lock, then it must be time to extend that
335 * lock as AFS locks time out after 5 minutes.
337 case AFS_VNODE_LOCK_GRANTED
:
340 ASSERT(!list_empty(&vnode
->granted_locks
));
342 key
= key_get(vnode
->lock_key
);
343 afs_set_lock_state(vnode
, AFS_VNODE_LOCK_EXTENDING
);
344 trace_afs_flock_ev(vnode
, NULL
, afs_flock_work_extending
, 0);
345 spin_unlock(&vnode
->lock
);
347 ret
= afs_extend_lock(vnode
, key
); /* RPC */
351 trace_afs_flock_ev(vnode
, NULL
, afs_flock_extend_fail
,
353 pr_warning("AFS: Failed to extend lock on {%llx:%llx} error %d\n",
354 vnode
->fid
.vid
, vnode
->fid
.vnode
, ret
);
357 spin_lock(&vnode
->lock
);
359 if (ret
== -ENOENT
) {
360 afs_kill_lockers_enoent(vnode
);
361 spin_unlock(&vnode
->lock
);
365 if (vnode
->lock_state
!= AFS_VNODE_LOCK_EXTENDING
)
367 afs_set_lock_state(vnode
, AFS_VNODE_LOCK_GRANTED
);
370 queue_delayed_work(afs_lock_manager
, &vnode
->lock_work
,
372 spin_unlock(&vnode
->lock
);
376 /* If we're waiting for a callback to indicate lock release, we can't
377 * actually rely on this, so need to recheck at regular intervals. The
378 * problem is that the server might not notify us if the lock just
379 * expires (say because a client died) rather than being explicitly
382 case AFS_VNODE_LOCK_WAITING_FOR_CB
:
384 afs_next_locker(vnode
, 0);
385 spin_unlock(&vnode
->lock
);
388 case AFS_VNODE_LOCK_DELETED
:
389 afs_kill_lockers_enoent(vnode
);
390 spin_unlock(&vnode
->lock
);
395 /* Looks like a lock request was withdrawn. */
396 spin_unlock(&vnode
->lock
);
403 * pass responsibility for the unlocking of a vnode on the server to the
404 * manager thread, lest a pending signal in the calling thread interrupt
406 * - the caller must hold the vnode lock
408 static void afs_defer_unlock(struct afs_vnode
*vnode
)
410 _enter("%u", vnode
->lock_state
);
412 if (list_empty(&vnode
->granted_locks
) &&
413 (vnode
->lock_state
== AFS_VNODE_LOCK_GRANTED
||
414 vnode
->lock_state
== AFS_VNODE_LOCK_EXTENDING
)) {
415 cancel_delayed_work(&vnode
->lock_work
);
417 afs_set_lock_state(vnode
, AFS_VNODE_LOCK_NEED_UNLOCK
);
418 trace_afs_flock_ev(vnode
, NULL
, afs_flock_defer_unlock
, 0);
419 queue_delayed_work(afs_lock_manager
, &vnode
->lock_work
, 0);
424 * Check that our view of the file metadata is up to date and check to see
425 * whether we think that we have a locking permit.
427 static int afs_do_setlk_check(struct afs_vnode
*vnode
, struct key
*key
,
428 enum afs_flock_mode mode
, afs_lock_type_t type
)
433 /* Make sure we've got a callback on this file and that our view of the
434 * data version is up to date.
436 ret
= afs_validate(vnode
, key
);
440 /* Check the permission set to see if we're actually going to be
441 * allowed to get a lock on this file.
443 ret
= afs_check_permit(vnode
, key
, &access
);
447 /* At a rough estimation, you need LOCK, WRITE or INSERT perm to
448 * read-lock a file and WRITE or INSERT perm to write-lock a file.
450 * We can't rely on the server to do this for us since if we want to
451 * share a read lock that we already have, we won't go the server.
453 if (type
== AFS_LOCK_READ
) {
454 if (!(access
& (AFS_ACE_INSERT
| AFS_ACE_WRITE
| AFS_ACE_LOCK
)))
457 if (!(access
& (AFS_ACE_INSERT
| AFS_ACE_WRITE
)))
465 * request a lock on a file on the server
467 static int afs_do_setlk(struct file
*file
, struct file_lock
*fl
)
469 struct inode
*inode
= locks_inode(file
);
470 struct afs_vnode
*vnode
= AFS_FS_I(inode
);
471 enum afs_flock_mode mode
= AFS_FS_S(inode
->i_sb
)->flock_mode
;
472 afs_lock_type_t type
;
473 struct key
*key
= afs_file_key(file
);
474 bool partial
, no_server_lock
= false;
477 if (mode
== afs_flock_mode_unset
)
478 mode
= afs_flock_mode_openafs
;
480 _enter("{%llx:%llu},%llu-%llu,%u,%u",
481 vnode
->fid
.vid
, vnode
->fid
.vnode
,
482 fl
->fl_start
, fl
->fl_end
, fl
->fl_type
, mode
);
484 fl
->fl_ops
= &afs_lock_ops
;
485 INIT_LIST_HEAD(&fl
->fl_u
.afs
.link
);
486 fl
->fl_u
.afs
.state
= AFS_LOCK_PENDING
;
488 partial
= (fl
->fl_start
!= 0 || fl
->fl_end
!= OFFSET_MAX
);
489 type
= (fl
->fl_type
== F_RDLCK
) ? AFS_LOCK_READ
: AFS_LOCK_WRITE
;
490 if (mode
== afs_flock_mode_write
&& partial
)
491 type
= AFS_LOCK_WRITE
;
493 ret
= afs_do_setlk_check(vnode
, key
, mode
, type
);
497 trace_afs_flock_op(vnode
, fl
, afs_flock_op_set_lock
);
499 /* AFS3 protocol only supports full-file locks and doesn't provide any
500 * method of upgrade/downgrade, so we need to emulate for partial-file
503 * The OpenAFS client only gets a server lock for a full-file lock and
504 * keeps partial-file locks local. Allow this behaviour to be emulated
507 if (mode
== afs_flock_mode_local
||
508 (partial
&& mode
== afs_flock_mode_openafs
)) {
509 no_server_lock
= true;
510 goto skip_server_lock
;
513 spin_lock(&vnode
->lock
);
514 list_add_tail(&fl
->fl_u
.afs
.link
, &vnode
->pending_locks
);
517 if (vnode
->lock_state
== AFS_VNODE_LOCK_DELETED
)
520 /* If we've already got a lock on the server then try to move to having
521 * the VFS grant the requested lock. Note that this means that other
522 * clients may get starved out.
524 _debug("try %u", vnode
->lock_state
);
525 if (vnode
->lock_state
== AFS_VNODE_LOCK_GRANTED
) {
526 if (type
== AFS_LOCK_READ
) {
527 _debug("instant readlock");
528 list_move_tail(&fl
->fl_u
.afs
.link
, &vnode
->granted_locks
);
529 fl
->fl_u
.afs
.state
= AFS_LOCK_GRANTED
;
530 goto vnode_is_locked_u
;
533 if (vnode
->lock_type
== AFS_LOCK_WRITE
) {
534 _debug("instant writelock");
535 list_move_tail(&fl
->fl_u
.afs
.link
, &vnode
->granted_locks
);
536 fl
->fl_u
.afs
.state
= AFS_LOCK_GRANTED
;
537 goto vnode_is_locked_u
;
541 if (vnode
->lock_state
== AFS_VNODE_LOCK_NONE
&&
542 !(fl
->fl_flags
& FL_SLEEP
)) {
544 if (type
== AFS_LOCK_READ
) {
545 if (vnode
->status
.lock_count
== -1)
546 goto lock_is_contended
; /* Write locked */
548 if (vnode
->status
.lock_count
!= 0)
549 goto lock_is_contended
; /* Locked */
553 if (vnode
->lock_state
!= AFS_VNODE_LOCK_NONE
)
557 /* We don't have a lock on this vnode and we aren't currently waiting
558 * for one either, so ask the server for a lock.
560 * Note that we need to be careful if we get interrupted by a signal
561 * after dispatching the request as we may still get the lock, even
562 * though we don't wait for the reply (it's not too bad a problem - the
563 * lock will expire in 5 mins anyway).
565 trace_afs_flock_ev(vnode
, fl
, afs_flock_try_to_lock
, 0);
566 vnode
->lock_key
= key_get(key
);
567 vnode
->lock_type
= type
;
568 afs_set_lock_state(vnode
, AFS_VNODE_LOCK_SETTING
);
569 spin_unlock(&vnode
->lock
);
571 ret
= afs_set_lock(vnode
, key
, type
); /* RPC */
573 spin_lock(&vnode
->lock
);
580 fl
->fl_u
.afs
.state
= ret
;
581 trace_afs_flock_ev(vnode
, fl
, afs_flock_fail_perm
, ret
);
582 list_del_init(&fl
->fl_u
.afs
.link
);
583 afs_next_locker(vnode
, ret
);
587 fl
->fl_u
.afs
.state
= ret
;
588 trace_afs_flock_ev(vnode
, fl
, afs_flock_fail_other
, ret
);
589 list_del_init(&fl
->fl_u
.afs
.link
);
590 afs_kill_lockers_enoent(vnode
);
594 fl
->fl_u
.afs
.state
= ret
;
595 trace_afs_flock_ev(vnode
, fl
, afs_flock_fail_other
, ret
);
596 list_del_init(&fl
->fl_u
.afs
.link
);
597 afs_next_locker(vnode
, 0);
601 /* The server doesn't have a lock-waiting queue, so the client
602 * will have to retry. The server will break the outstanding
603 * callbacks on a file when a lock is released.
605 ASSERT(list_empty(&vnode
->granted_locks
));
606 ASSERTCMP(vnode
->pending_locks
.next
, ==, &fl
->fl_u
.afs
.link
);
607 goto lock_is_contended
;
610 afs_set_lock_state(vnode
, AFS_VNODE_LOCK_GRANTED
);
611 trace_afs_flock_ev(vnode
, fl
, afs_flock_acquired
, type
);
612 afs_grant_locks(vnode
);
613 goto vnode_is_locked_u
;
617 spin_unlock(&vnode
->lock
);
619 /* the lock has been granted by the server... */
620 ASSERTCMP(fl
->fl_u
.afs
.state
, ==, AFS_LOCK_GRANTED
);
623 /* ... but the VFS still needs to distribute access on this client. */
624 trace_afs_flock_ev(vnode
, fl
, afs_flock_vfs_locking
, 0);
625 ret
= locks_lock_file_wait(file
, fl
);
626 trace_afs_flock_ev(vnode
, fl
, afs_flock_vfs_lock
, ret
);
628 goto vfs_rejected_lock
;
630 /* Again, make sure we've got a callback on this file and, again, make
631 * sure that our view of the data version is up to date (we ignore
632 * errors incurred here and deal with the consequences elsewhere).
634 afs_validate(vnode
, key
);
639 if (!(fl
->fl_flags
& FL_SLEEP
)) {
640 list_del_init(&fl
->fl_u
.afs
.link
);
641 afs_next_locker(vnode
, 0);
646 afs_set_lock_state(vnode
, AFS_VNODE_LOCK_WAITING_FOR_CB
);
647 trace_afs_flock_ev(vnode
, fl
, afs_flock_would_block
, ret
);
648 queue_delayed_work(afs_lock_manager
, &vnode
->lock_work
, HZ
* 5);
651 /* We're going to have to wait. Either this client doesn't have a lock
652 * on the server yet and we need to wait for a callback to occur, or
653 * the client does have a lock on the server, but it's shared and we
654 * need an exclusive lock.
656 spin_unlock(&vnode
->lock
);
658 trace_afs_flock_ev(vnode
, fl
, afs_flock_waiting
, 0);
659 ret
= wait_event_interruptible(fl
->fl_wait
,
660 fl
->fl_u
.afs
.state
!= AFS_LOCK_PENDING
);
661 trace_afs_flock_ev(vnode
, fl
, afs_flock_waited
, ret
);
663 if (fl
->fl_u
.afs
.state
>= 0 && fl
->fl_u
.afs
.state
!= AFS_LOCK_GRANTED
) {
664 spin_lock(&vnode
->lock
);
666 switch (fl
->fl_u
.afs
.state
) {
667 case AFS_LOCK_YOUR_TRY
:
668 fl
->fl_u
.afs
.state
= AFS_LOCK_PENDING
;
670 case AFS_LOCK_PENDING
:
672 /* We need to retry the lock. We may not be
673 * notified by the server if it just expired
674 * rather than being released.
676 ASSERTCMP(vnode
->lock_state
, ==, AFS_VNODE_LOCK_WAITING_FOR_CB
);
677 afs_set_lock_state(vnode
, AFS_VNODE_LOCK_SETTING
);
678 fl
->fl_u
.afs
.state
= AFS_LOCK_PENDING
;
682 case AFS_LOCK_GRANTED
:
687 spin_unlock(&vnode
->lock
);
690 if (fl
->fl_u
.afs
.state
== AFS_LOCK_GRANTED
)
691 goto vnode_is_locked
;
692 ret
= fl
->fl_u
.afs
.state
;
696 /* The VFS rejected the lock we just obtained, so we have to discard
697 * what we just got. We defer this to the lock manager work item to
700 _debug("vfs refused %d", ret
);
703 spin_lock(&vnode
->lock
);
704 list_del_init(&fl
->fl_u
.afs
.link
);
705 afs_defer_unlock(vnode
);
708 spin_unlock(&vnode
->lock
);
710 _leave(" = %d", ret
);
715 * unlock on a file on the server
717 static int afs_do_unlk(struct file
*file
, struct file_lock
*fl
)
719 struct afs_vnode
*vnode
= AFS_FS_I(locks_inode(file
));
722 _enter("{%llx:%llu},%u", vnode
->fid
.vid
, vnode
->fid
.vnode
, fl
->fl_type
);
724 trace_afs_flock_op(vnode
, fl
, afs_flock_op_unlock
);
726 /* Flush all pending writes before doing anything with locks. */
729 ret
= locks_lock_file_wait(file
, fl
);
730 _leave(" = %d [%u]", ret
, vnode
->lock_state
);
735 * return information about a lock we currently hold, if indeed we hold one
737 static int afs_do_getlk(struct file
*file
, struct file_lock
*fl
)
739 struct afs_vnode
*vnode
= AFS_FS_I(locks_inode(file
));
740 struct key
*key
= afs_file_key(file
);
745 if (vnode
->lock_state
== AFS_VNODE_LOCK_DELETED
)
748 fl
->fl_type
= F_UNLCK
;
750 /* check local lock records first */
751 posix_test_lock(file
, fl
);
752 if (fl
->fl_type
== F_UNLCK
) {
753 /* no local locks; consult the server */
754 ret
= afs_fetch_status(vnode
, key
, false, NULL
);
758 lock_count
= READ_ONCE(vnode
->status
.lock_count
);
759 if (lock_count
!= 0) {
761 fl
->fl_type
= F_RDLCK
;
763 fl
->fl_type
= F_WRLCK
;
765 fl
->fl_end
= OFFSET_MAX
;
772 _leave(" = %d [%hd]", ret
, fl
->fl_type
);
777 * manage POSIX locks on a file
779 int afs_lock(struct file
*file
, int cmd
, struct file_lock
*fl
)
781 struct afs_vnode
*vnode
= AFS_FS_I(locks_inode(file
));
782 enum afs_flock_operation op
;
785 _enter("{%llx:%llu},%d,{t=%x,fl=%x,r=%Ld:%Ld}",
786 vnode
->fid
.vid
, vnode
->fid
.vnode
, cmd
,
787 fl
->fl_type
, fl
->fl_flags
,
788 (long long) fl
->fl_start
, (long long) fl
->fl_end
);
790 /* AFS doesn't support mandatory locks */
791 if (__mandatory_lock(&vnode
->vfs_inode
) && fl
->fl_type
!= F_UNLCK
)
795 return afs_do_getlk(file
, fl
);
797 fl
->fl_u
.afs
.debug_id
= atomic_inc_return(&afs_file_lock_debug_id
);
798 trace_afs_flock_op(vnode
, fl
, afs_flock_op_lock
);
800 if (fl
->fl_type
== F_UNLCK
)
801 ret
= afs_do_unlk(file
, fl
);
803 ret
= afs_do_setlk(file
, fl
);
806 case 0: op
= afs_flock_op_return_ok
; break;
807 case -EAGAIN
: op
= afs_flock_op_return_eagain
; break;
808 case -EDEADLK
: op
= afs_flock_op_return_edeadlk
; break;
809 default: op
= afs_flock_op_return_error
; break;
811 trace_afs_flock_op(vnode
, fl
, op
);
816 * manage FLOCK locks on a file
818 int afs_flock(struct file
*file
, int cmd
, struct file_lock
*fl
)
820 struct afs_vnode
*vnode
= AFS_FS_I(locks_inode(file
));
821 enum afs_flock_operation op
;
824 _enter("{%llx:%llu},%d,{t=%x,fl=%x}",
825 vnode
->fid
.vid
, vnode
->fid
.vnode
, cmd
,
826 fl
->fl_type
, fl
->fl_flags
);
829 * No BSD flocks over NFS allowed.
830 * Note: we could try to fake a POSIX lock request here by
831 * using ((u32) filp | 0x80000000) or some such as the pid.
832 * Not sure whether that would be unique, though, or whether
833 * that would break in other places.
835 if (!(fl
->fl_flags
& FL_FLOCK
))
838 fl
->fl_u
.afs
.debug_id
= atomic_inc_return(&afs_file_lock_debug_id
);
839 trace_afs_flock_op(vnode
, fl
, afs_flock_op_flock
);
841 /* we're simulating flock() locks using posix locks on the server */
842 if (fl
->fl_type
== F_UNLCK
)
843 ret
= afs_do_unlk(file
, fl
);
845 ret
= afs_do_setlk(file
, fl
);
848 case 0: op
= afs_flock_op_return_ok
; break;
849 case -EAGAIN
: op
= afs_flock_op_return_eagain
; break;
850 case -EDEADLK
: op
= afs_flock_op_return_edeadlk
; break;
851 default: op
= afs_flock_op_return_error
; break;
853 trace_afs_flock_op(vnode
, fl
, op
);
858 * the POSIX lock management core VFS code copies the lock record and adds the
859 * copy into its own list, so we need to add that copy to the vnode's lock
860 * queue in the same place as the original (which will be deleted shortly
863 static void afs_fl_copy_lock(struct file_lock
*new, struct file_lock
*fl
)
865 struct afs_vnode
*vnode
= AFS_FS_I(locks_inode(fl
->fl_file
));
869 new->fl_u
.afs
.debug_id
= atomic_inc_return(&afs_file_lock_debug_id
);
871 spin_lock(&vnode
->lock
);
872 trace_afs_flock_op(vnode
, new, afs_flock_op_copy_lock
);
873 list_add(&new->fl_u
.afs
.link
, &fl
->fl_u
.afs
.link
);
874 spin_unlock(&vnode
->lock
);
878 * need to remove this lock from the vnode queue when it's removed from the
881 static void afs_fl_release_private(struct file_lock
*fl
)
883 struct afs_vnode
*vnode
= AFS_FS_I(locks_inode(fl
->fl_file
));
887 spin_lock(&vnode
->lock
);
889 trace_afs_flock_op(vnode
, fl
, afs_flock_op_release_lock
);
890 list_del_init(&fl
->fl_u
.afs
.link
);
891 if (list_empty(&vnode
->granted_locks
))
892 afs_defer_unlock(vnode
);
894 _debug("state %u for %p", vnode
->lock_state
, vnode
);
895 spin_unlock(&vnode
->lock
);