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authorDavid Howells <dhowells@redhat.com>2007-07-16 02:40:12 -0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-16 12:05:43 -0400
commite8d6c554126b830217c5e9f549e0e21f865a0a8a (patch)
treec43219c6ef4e6a9b4f0ac46d6bd8b675dc249a8b
parentb0fed3140f57c435d2783b698c5090f325c22bad (diff)
AFS: implement file locking
Implement file locking for AFS. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/afs/Makefile1
-rw-r--r--fs/afs/afs.h8
-rw-r--r--fs/afs/afs_fs.h3
-rw-r--r--fs/afs/callback.c3
-rw-r--r--fs/afs/dir.c1
-rw-r--r--fs/afs/file.c2
-rw-r--r--fs/afs/flock.c558
-rw-r--r--fs/afs/fsclient.c155
-rw-r--r--fs/afs/internal.h30
-rw-r--r--fs/afs/main.c1
-rw-r--r--fs/afs/misc.c1
-rw-r--r--fs/afs/super.c3
-rw-r--r--fs/afs/vnode.c130
-rw-r--r--include/linux/fs.h4
14 files changed, 885 insertions, 15 deletions
diff --git a/fs/afs/Makefile b/fs/afs/Makefile
index 73ce561f3ea0..a66671082cfb 100644
--- a/fs/afs/Makefile
+++ b/fs/afs/Makefile
@@ -8,6 +8,7 @@ kafs-objs := \
8 cmservice.o \ 8 cmservice.o \
9 dir.o \ 9 dir.o \
10 file.o \ 10 file.o \
11 flock.o \
11 fsclient.o \ 12 fsclient.o \
12 inode.o \ 13 inode.o \
13 main.o \ 14 main.o \
diff --git a/fs/afs/afs.h b/fs/afs/afs.h
index 245257948140..c548aa346f0d 100644
--- a/fs/afs/afs.h
+++ b/fs/afs/afs.h
@@ -37,6 +37,13 @@ typedef enum {
37 AFS_FTYPE_SYMLINK = 3, 37 AFS_FTYPE_SYMLINK = 3,
38} afs_file_type_t; 38} afs_file_type_t;
39 39
40typedef enum {
41 AFS_LOCK_READ = 0, /* read lock request */
42 AFS_LOCK_WRITE = 1, /* write lock request */
43} afs_lock_type_t;
44
45#define AFS_LOCKWAIT (5 * 60) /* time until a lock times out (seconds) */
46
40/* 47/*
41 * AFS file identifier 48 * AFS file identifier
42 */ 49 */
@@ -120,6 +127,7 @@ struct afs_file_status {
120 struct afs_fid parent; /* parent dir ID for non-dirs only */ 127 struct afs_fid parent; /* parent dir ID for non-dirs only */
121 time_t mtime_client; /* last time client changed data */ 128 time_t mtime_client; /* last time client changed data */
122 time_t mtime_server; /* last time server changed data */ 129 time_t mtime_server; /* last time server changed data */
130 s32 lock_count; /* file lock count (0=UNLK -1=WRLCK +ve=#RDLCK */
123}; 131};
124 132
125/* 133/*
diff --git a/fs/afs/afs_fs.h b/fs/afs/afs_fs.h
index a18c374ebe08..eb647323d8f0 100644
--- a/fs/afs/afs_fs.h
+++ b/fs/afs/afs_fs.h
@@ -31,6 +31,9 @@ enum AFS_FS_Operations {
31 FSGETVOLUMEINFO = 148, /* AFS Get information about a volume */ 31 FSGETVOLUMEINFO = 148, /* AFS Get information about a volume */
32 FSGETVOLUMESTATUS = 149, /* AFS Get volume status information */ 32 FSGETVOLUMESTATUS = 149, /* AFS Get volume status information */
33 FSGETROOTVOLUME = 151, /* AFS Get root volume name */ 33 FSGETROOTVOLUME = 151, /* AFS Get root volume name */
34 FSSETLOCK = 156, /* AFS Request a file lock */
35 FSEXTENDLOCK = 157, /* AFS Extend a file lock */
36 FSRELEASELOCK = 158, /* AFS Release a file lock */
34 FSLOOKUP = 161, /* AFS lookup file in directory */ 37 FSLOOKUP = 161, /* AFS lookup file in directory */
35 FSFETCHDATA64 = 65537, /* AFS Fetch file data */ 38 FSFETCHDATA64 = 65537, /* AFS Fetch file data */
36 FSSTOREDATA64 = 65538, /* AFS Store file data */ 39 FSSTOREDATA64 = 65538, /* AFS Store file data */
diff --git a/fs/afs/callback.c b/fs/afs/callback.c
index bacf518c6fa8..b8243945818d 100644
--- a/fs/afs/callback.c
+++ b/fs/afs/callback.c
@@ -125,6 +125,9 @@ static void afs_break_callback(struct afs_server *server,
125 spin_unlock(&server->cb_lock); 125 spin_unlock(&server->cb_lock);
126 126
127 queue_work(afs_callback_update_worker, &vnode->cb_broken_work); 127 queue_work(afs_callback_update_worker, &vnode->cb_broken_work);
128 if (list_empty(&vnode->granted_locks) &&
129 !list_empty(&vnode->pending_locks))
130 afs_lock_may_be_available(vnode);
128 spin_unlock(&vnode->lock); 131 spin_unlock(&vnode->lock);
129 } 132 }
130} 133}
diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index 546c59522eb1..33fe39ad4e03 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -44,6 +44,7 @@ const struct file_operations afs_dir_file_operations = {
44 .open = afs_dir_open, 44 .open = afs_dir_open,
45 .release = afs_release, 45 .release = afs_release,
46 .readdir = afs_readdir, 46 .readdir = afs_readdir,
47 .lock = afs_lock,
47}; 48};
48 49
49const struct inode_operations afs_dir_inode_operations = { 50const struct inode_operations afs_dir_inode_operations = {
diff --git a/fs/afs/file.c b/fs/afs/file.c
index aede7eb66dd4..525f7c56e068 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -34,6 +34,8 @@ const struct file_operations afs_file_operations = {
34 .mmap = generic_file_readonly_mmap, 34 .mmap = generic_file_readonly_mmap,
35 .splice_read = generic_file_splice_read, 35 .splice_read = generic_file_splice_read,
36 .fsync = afs_fsync, 36 .fsync = afs_fsync,
37 .lock = afs_lock,
38 .flock = afs_flock,
37}; 39};
38 40
39const struct inode_operations afs_file_inode_operations = { 41const struct inode_operations afs_file_inode_operations = {
diff --git a/fs/afs/flock.c b/fs/afs/flock.c
new file mode 100644
index 000000000000..8f07f8d1bfa9
--- /dev/null
+++ b/fs/afs/flock.c
@@ -0,0 +1,558 @@
1/* AFS file locking support
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
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.
10 */
11
12#include <linux/smp_lock.h>
13#include "internal.h"
14
15#define AFS_LOCK_GRANTED 0
16#define AFS_LOCK_PENDING 1
17
18static void afs_fl_copy_lock(struct file_lock *new, struct file_lock *fl);
19static void afs_fl_release_private(struct file_lock *fl);
20
21static struct workqueue_struct *afs_lock_manager;
22
23static struct file_lock_operations afs_lock_ops = {
24 .fl_copy_lock = afs_fl_copy_lock,
25 .fl_release_private = afs_fl_release_private,
26};
27
28/*
29 * initialise the lock manager thread if it isn't already running
30 */
31static int afs_init_lock_manager(void)
32{
33 if (!afs_lock_manager) {
34 afs_lock_manager = create_singlethread_workqueue("kafs_lockd");
35 if (!afs_lock_manager)
36 return -ENOMEM;
37 }
38 return 0;
39}
40
41/*
42 * destroy the lock manager thread if it's running
43 */
44void __exit afs_kill_lock_manager(void)
45{
46 if (afs_lock_manager)
47 destroy_workqueue(afs_lock_manager);
48}
49
50/*
51 * if the callback is broken on this vnode, then the lock may now be available
52 */
53void afs_lock_may_be_available(struct afs_vnode *vnode)
54{
55 _enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode);
56
57 queue_delayed_work(afs_lock_manager, &vnode->lock_work, 0);
58}
59
60/*
61 * the lock will time out in 5 minutes unless we extend it, so schedule
62 * extension in a bit less than that time
63 */
64static void afs_schedule_lock_extension(struct afs_vnode *vnode)
65{
66 queue_delayed_work(afs_lock_manager, &vnode->lock_work,
67 AFS_LOCKWAIT * HZ / 2);
68}
69
70/*
71 * do work for a lock, including:
72 * - probing for a lock we're waiting on but didn't get immediately
73 * - extending a lock that's close to timing out
74 */
75void afs_lock_work(struct work_struct *work)
76{
77 struct afs_vnode *vnode =
78 container_of(work, struct afs_vnode, lock_work.work);
79 struct file_lock *fl;
80 afs_lock_type_t type;
81 struct key *key;
82 int ret;
83
84 _enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode);
85
86 spin_lock(&vnode->lock);
87
88 if (test_bit(AFS_VNODE_UNLOCKING, &vnode->flags)) {
89 _debug("unlock");
90 spin_unlock(&vnode->lock);
91
92 /* attempt to release the server lock; if it fails, we just
93 * wait 5 minutes and it'll time out anyway */
94 ret = afs_vnode_release_lock(vnode, vnode->unlock_key);
95 if (ret < 0)
96 printk(KERN_WARNING "AFS:"
97 " Failed to release lock on {%x:%x} error %d\n",
98 vnode->fid.vid, vnode->fid.vnode, ret);
99
100 spin_lock(&vnode->lock);
101 key_put(vnode->unlock_key);
102 vnode->unlock_key = NULL;
103 clear_bit(AFS_VNODE_UNLOCKING, &vnode->flags);
104 }
105
106 /* if we've got a lock, then it must be time to extend that lock as AFS
107 * locks time out after 5 minutes */
108 if (!list_empty(&vnode->granted_locks)) {
109 _debug("extend");
110
111 if (test_and_set_bit(AFS_VNODE_LOCKING, &vnode->flags))
112 BUG();
113 fl = list_entry(vnode->granted_locks.next,
114 struct file_lock, fl_u.afs.link);
115 key = key_get(fl->fl_file->private_data);
116 spin_unlock(&vnode->lock);
117
118 ret = afs_vnode_extend_lock(vnode, key);
119 clear_bit(AFS_VNODE_LOCKING, &vnode->flags);
120 key_put(key);
121 switch (ret) {
122 case 0:
123 afs_schedule_lock_extension(vnode);
124 break;
125 default:
126 /* ummm... we failed to extend the lock - retry
127 * extension shortly */
128 printk(KERN_WARNING "AFS:"
129 " Failed to extend lock on {%x:%x} error %d\n",
130 vnode->fid.vid, vnode->fid.vnode, ret);
131 queue_delayed_work(afs_lock_manager, &vnode->lock_work,
132 HZ * 10);
133 break;
134 }
135 _leave(" [extend]");
136 return;
137 }
138
139 /* if we don't have a granted lock, then we must've been called back by
140 * the server, and so if might be possible to get a lock we're
141 * currently waiting for */
142 if (!list_empty(&vnode->pending_locks)) {
143 _debug("get");
144
145 if (test_and_set_bit(AFS_VNODE_LOCKING, &vnode->flags))
146 BUG();
147 fl = list_entry(vnode->pending_locks.next,
148 struct file_lock, fl_u.afs.link);
149 key = key_get(fl->fl_file->private_data);
150 type = (fl->fl_type == F_RDLCK) ?
151 AFS_LOCK_READ : AFS_LOCK_WRITE;
152 spin_unlock(&vnode->lock);
153
154 ret = afs_vnode_set_lock(vnode, key, type);
155 clear_bit(AFS_VNODE_LOCKING, &vnode->flags);
156 switch (ret) {
157 case -EWOULDBLOCK:
158 _debug("blocked");
159 break;
160 case 0:
161 _debug("acquired");
162 if (type == AFS_LOCK_READ)
163 set_bit(AFS_VNODE_READLOCKED, &vnode->flags);
164 else
165 set_bit(AFS_VNODE_WRITELOCKED, &vnode->flags);
166 ret = AFS_LOCK_GRANTED;
167 default:
168 spin_lock(&vnode->lock);
169 /* the pending lock may have been withdrawn due to a
170 * signal */
171 if (list_entry(vnode->pending_locks.next,
172 struct file_lock, fl_u.afs.link) == fl) {
173 fl->fl_u.afs.state = ret;
174 if (ret == AFS_LOCK_GRANTED)
175 list_move_tail(&fl->fl_u.afs.link,
176 &vnode->granted_locks);
177 else
178 list_del_init(&fl->fl_u.afs.link);
179 wake_up(&fl->fl_wait);
180 spin_unlock(&vnode->lock);
181 } else {
182 _debug("withdrawn");
183 clear_bit(AFS_VNODE_READLOCKED, &vnode->flags);
184 clear_bit(AFS_VNODE_WRITELOCKED, &vnode->flags);
185 spin_unlock(&vnode->lock);
186 afs_vnode_release_lock(vnode, key);
187 if (!list_empty(&vnode->pending_locks))
188 afs_lock_may_be_available(vnode);
189 }
190 break;
191 }
192 key_put(key);
193 _leave(" [pend]");
194 return;
195 }
196
197 /* looks like the lock request was withdrawn on a signal */
198 spin_unlock(&vnode->lock);
199 _leave(" [no locks]");
200}
201
202/*
203 * pass responsibility for the unlocking of a vnode on the server to the
204 * manager thread, lest a pending signal in the calling thread interrupt
205 * AF_RXRPC
206 * - the caller must hold the vnode lock
207 */
208static void afs_defer_unlock(struct afs_vnode *vnode, struct key *key)
209{
210 cancel_delayed_work(&vnode->lock_work);
211 if (!test_and_clear_bit(AFS_VNODE_READLOCKED, &vnode->flags) &&
212 !test_and_clear_bit(AFS_VNODE_WRITELOCKED, &vnode->flags))
213 BUG();
214 if (test_and_set_bit(AFS_VNODE_UNLOCKING, &vnode->flags))
215 BUG();
216 vnode->unlock_key = key_get(key);
217 afs_lock_may_be_available(vnode);
218}
219
220/*
221 * request a lock on a file on the server
222 */
223static int afs_do_setlk(struct file *file, struct file_lock *fl)
224{
225 struct afs_vnode *vnode = AFS_FS_I(file->f_mapping->host);
226 afs_lock_type_t type;
227 struct key *key = file->private_data;
228 int ret;
229
230 _enter("{%x:%u},%u", vnode->fid.vid, vnode->fid.vnode, fl->fl_type);
231
232 /* only whole-file locks are supported */
233 if (fl->fl_start != 0 || fl->fl_end != OFFSET_MAX)
234 return -EINVAL;
235
236 ret = afs_init_lock_manager();
237 if (ret < 0)
238 return ret;
239
240 fl->fl_ops = &afs_lock_ops;
241 INIT_LIST_HEAD(&fl->fl_u.afs.link);
242 fl->fl_u.afs.state = AFS_LOCK_PENDING;
243
244 type = (fl->fl_type == F_RDLCK) ? AFS_LOCK_READ : AFS_LOCK_WRITE;
245
246 lock_kernel();
247
248 /* make sure we've got a callback on this file and that our view of the
249 * data version is up to date */
250 ret = afs_vnode_fetch_status(vnode, NULL, key);
251 if (ret < 0)
252 goto error;
253
254 if (vnode->status.lock_count != 0 && !(fl->fl_flags & FL_SLEEP)) {
255 ret = -EAGAIN;
256 goto error;
257 }
258
259 spin_lock(&vnode->lock);
260
261 if (list_empty(&vnode->pending_locks)) {
262 /* if there's no-one else with a lock on this vnode, then we
263 * need to ask the server for a lock */
264 if (list_empty(&vnode->granted_locks)) {
265 _debug("not locked");
266 ASSERTCMP(vnode->flags &
267 ((1 << AFS_VNODE_LOCKING) |
268 (1 << AFS_VNODE_READLOCKED) |
269 (1 << AFS_VNODE_WRITELOCKED)), ==, 0);
270 list_add_tail(&fl->fl_u.afs.link, &vnode->pending_locks);
271 set_bit(AFS_VNODE_LOCKING, &vnode->flags);
272 spin_unlock(&vnode->lock);
273
274 ret = afs_vnode_set_lock(vnode, key, type);
275 clear_bit(AFS_VNODE_LOCKING, &vnode->flags);
276 switch (ret) {
277 case 0:
278 goto acquired_server_lock;
279 case -EWOULDBLOCK:
280 spin_lock(&vnode->lock);
281 ASSERT(list_empty(&vnode->granted_locks));
282 ASSERTCMP(vnode->pending_locks.next, ==,
283 &fl->fl_u.afs.link);
284 goto wait;
285 default:
286 spin_lock(&vnode->lock);
287 list_del_init(&fl->fl_u.afs.link);
288 spin_unlock(&vnode->lock);
289 goto error;
290 }
291 }
292
293 /* if we've already got a readlock on the server and no waiting
294 * writelocks, then we might be able to instantly grant another
295 * readlock */
296 if (type == AFS_LOCK_READ &&
297 vnode->flags & (1 << AFS_VNODE_READLOCKED)) {
298 _debug("instant readlock");
299 ASSERTCMP(vnode->flags &
300 ((1 << AFS_VNODE_LOCKING) |
301 (1 << AFS_VNODE_WRITELOCKED)), ==, 0);
302 ASSERT(!list_empty(&vnode->granted_locks));
303 goto sharing_existing_lock;
304 }
305 }
306
307 /* otherwise, we need to wait for a local lock to become available */
308 _debug("wait local");
309 list_add_tail(&fl->fl_u.afs.link, &vnode->pending_locks);
310wait:
311 if (!(fl->fl_flags & FL_SLEEP)) {
312 _debug("noblock");
313 ret = -EAGAIN;
314 goto abort_attempt;
315 }
316 spin_unlock(&vnode->lock);
317
318 /* now we need to sleep and wait for the lock manager thread to get the
319 * lock from the server */
320 _debug("sleep");
321 ret = wait_event_interruptible(fl->fl_wait,
322 fl->fl_u.afs.state <= AFS_LOCK_GRANTED);
323 if (fl->fl_u.afs.state <= AFS_LOCK_GRANTED) {
324 ret = fl->fl_u.afs.state;
325 if (ret < 0)
326 goto error;
327 spin_lock(&vnode->lock);
328 goto given_lock;
329 }
330
331 /* we were interrupted, but someone may still be in the throes of
332 * giving us the lock */
333 _debug("intr");
334 ASSERTCMP(ret, ==, -ERESTARTSYS);
335
336 spin_lock(&vnode->lock);
337 if (fl->fl_u.afs.state <= AFS_LOCK_GRANTED) {
338 ret = fl->fl_u.afs.state;
339 if (ret < 0) {
340 spin_unlock(&vnode->lock);
341 goto error;
342 }
343 goto given_lock;
344 }
345
346abort_attempt:
347 /* we aren't going to get the lock, either because we're unwilling to
348 * wait, or because some signal happened */
349 _debug("abort");
350 if (list_empty(&vnode->granted_locks) &&
351 vnode->pending_locks.next == &fl->fl_u.afs.link) {
352 if (vnode->pending_locks.prev != &fl->fl_u.afs.link) {
353 /* kick the next pending lock into having a go */
354 list_del_init(&fl->fl_u.afs.link);
355 afs_lock_may_be_available(vnode);
356 }
357 } else {
358 list_del_init(&fl->fl_u.afs.link);
359 }
360 spin_unlock(&vnode->lock);
361 goto error;
362
363acquired_server_lock:
364 /* we've acquired a server lock, but it needs to be renewed after 5
365 * mins */
366 spin_lock(&vnode->lock);
367 afs_schedule_lock_extension(vnode);
368 if (type == AFS_LOCK_READ)
369 set_bit(AFS_VNODE_READLOCKED, &vnode->flags);
370 else
371 set_bit(AFS_VNODE_WRITELOCKED, &vnode->flags);
372sharing_existing_lock:
373 /* the lock has been granted as far as we're concerned... */
374 fl->fl_u.afs.state = AFS_LOCK_GRANTED;
375 list_move_tail(&fl->fl_u.afs.link, &vnode->granted_locks);
376given_lock:
377 /* ... but we do still need to get the VFS's blessing */
378 ASSERT(!(vnode->flags & (1 << AFS_VNODE_LOCKING)));
379 ASSERT((vnode->flags & ((1 << AFS_VNODE_READLOCKED) |
380 (1 << AFS_VNODE_WRITELOCKED))) != 0);
381 ret = posix_lock_file(file, fl, NULL);
382 if (ret < 0)
383 goto vfs_rejected_lock;
384 spin_unlock(&vnode->lock);
385
386 /* again, make sure we've got a callback on this file and, again, make
387 * sure that our view of the data version is up to date (we ignore
388 * errors incurred here and deal with the consequences elsewhere) */
389 afs_vnode_fetch_status(vnode, NULL, key);
390
391error:
392 unlock_kernel();
393 _leave(" = %d", ret);
394 return ret;
395
396vfs_rejected_lock:
397 /* the VFS rejected the lock we just obtained, so we have to discard
398 * what we just got */
399 _debug("vfs refused %d", ret);
400 list_del_init(&fl->fl_u.afs.link);
401 if (list_empty(&vnode->granted_locks))
402 afs_defer_unlock(vnode, key);
403 spin_unlock(&vnode->lock);
404 goto abort_attempt;
405}
406
407/*
408 * unlock on a file on the server
409 */
410static int afs_do_unlk(struct file *file, struct file_lock *fl)
411{
412 struct afs_vnode *vnode = AFS_FS_I(file->f_mapping->host);
413 struct key *key = file->private_data;
414 int ret;
415
416 _enter("{%x:%u},%u", vnode->fid.vid, vnode->fid.vnode, fl->fl_type);
417
418 /* only whole-file unlocks are supported */
419 if (fl->fl_start != 0 || fl->fl_end != OFFSET_MAX)
420 return -EINVAL;
421
422 fl->fl_ops = &afs_lock_ops;
423 INIT_LIST_HEAD(&fl->fl_u.afs.link);
424 fl->fl_u.afs.state = AFS_LOCK_PENDING;
425
426 spin_lock(&vnode->lock);
427 ret = posix_lock_file(file, fl, NULL);
428 if (ret < 0) {
429 spin_unlock(&vnode->lock);
430 _leave(" = %d [vfs]", ret);
431 return ret;
432 }
433
434 /* discard the server lock only if all granted locks are gone */
435 if (list_empty(&vnode->granted_locks))
436 afs_defer_unlock(vnode, key);
437 spin_unlock(&vnode->lock);
438 _leave(" = 0");
439 return 0;
440}
441
442/*
443 * return information about a lock we currently hold, if indeed we hold one
444 */
445static int afs_do_getlk(struct file *file, struct file_lock *fl)
446{
447 struct afs_vnode *vnode = AFS_FS_I(file->f_mapping->host);
448 struct key *key = file->private_data;
449 int ret, lock_count;
450
451 _enter("");
452
453 fl->fl_type = F_UNLCK;
454
455 mutex_lock(&vnode->vfs_inode.i_mutex);
456
457 /* check local lock records first */
458 ret = 0;
459 if (posix_test_lock(file, fl) == 0) {
460 /* no local locks; consult the server */
461 ret = afs_vnode_fetch_status(vnode, NULL, key);
462 if (ret < 0)
463 goto error;
464 lock_count = vnode->status.lock_count;
465 if (lock_count) {
466 if (lock_count > 0)
467 fl->fl_type = F_RDLCK;
468 else
469 fl->fl_type = F_WRLCK;
470 fl->fl_start = 0;
471 fl->fl_end = OFFSET_MAX;
472 }
473 }
474
475error:
476 mutex_unlock(&vnode->vfs_inode.i_mutex);
477 _leave(" = %d [%hd]", ret, fl->fl_type);
478 return ret;
479}
480
481/*
482 * manage POSIX locks on a file
483 */
484int afs_lock(struct file *file, int cmd, struct file_lock *fl)
485{
486 struct afs_vnode *vnode = AFS_FS_I(file->f_dentry->d_inode);
487
488 _enter("{%x:%u},%d,{t=%x,fl=%x,r=%Ld:%Ld}",
489 vnode->fid.vid, vnode->fid.vnode, cmd,
490 fl->fl_type, fl->fl_flags,
491 (long long) fl->fl_start, (long long) fl->fl_end);
492
493 /* AFS doesn't support mandatory locks */
494 if ((vnode->vfs_inode.i_mode & (S_ISGID | S_IXGRP)) == S_ISGID &&
495 fl->fl_type != F_UNLCK)
496 return -ENOLCK;
497
498 if (IS_GETLK(cmd))
499 return afs_do_getlk(file, fl);
500 if (fl->fl_type == F_UNLCK)
501 return afs_do_unlk(file, fl);
502 return afs_do_setlk(file, fl);
503}
504
505/*
506 * manage FLOCK locks on a file
507 */
508int afs_flock(struct file *file, int cmd, struct file_lock *fl)
509{
510 struct afs_vnode *vnode = AFS_FS_I(file->f_dentry->d_inode);
511
512 _enter("{%x:%u},%d,{t=%x,fl=%x}",
513 vnode->fid.vid, vnode->fid.vnode, cmd,
514 fl->fl_type, fl->fl_flags);
515
516 /*
517 * No BSD flocks over NFS allowed.
518 * Note: we could try to fake a POSIX lock request here by
519 * using ((u32) filp | 0x80000000) or some such as the pid.
520 * Not sure whether that would be unique, though, or whether
521 * that would break in other places.
522 */
523 if (!(fl->fl_flags & FL_FLOCK))
524 return -ENOLCK;
525
526 /* we're simulating flock() locks using posix locks on the server */
527 fl->fl_owner = (fl_owner_t) file;
528 fl->fl_start = 0;
529 fl->fl_end = OFFSET_MAX;
530
531 if (fl->fl_type == F_UNLCK)
532 return afs_do_unlk(file, fl);
533 return afs_do_setlk(file, fl);
534}
535
536/*
537 * the POSIX lock management core VFS code copies the lock record and adds the
538 * copy into its own list, so we need to add that copy to the vnode's lock
539 * queue in the same place as the original (which will be deleted shortly
540 * after)
541 */
542static void afs_fl_copy_lock(struct file_lock *new, struct file_lock *fl)
543{
544 _enter("");
545
546 list_add(&new->fl_u.afs.link, &fl->fl_u.afs.link);
547}
548
549/*
550 * need to remove this lock from the vnode queue when it's removed from the
551 * VFS's list
552 */
553static void afs_fl_release_private(struct file_lock *fl)
554{
555 _enter("");
556
557 list_del_init(&fl->fl_u.afs.link);
558}
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index 5dff1308b6f0..023b95b0d9d7 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -67,7 +67,7 @@ static void xdr_decode_AFSFetchStatus(const __be32 **_bp,
67 EXTRACT(status->group); 67 EXTRACT(status->group);
68 bp++; /* sync counter */ 68 bp++; /* sync counter */
69 data_version |= (u64) ntohl(*bp++) << 32; 69 data_version |= (u64) ntohl(*bp++) << 32;
70 bp++; /* lock count */ 70 EXTRACT(status->lock_count);
71 size |= (u64) ntohl(*bp++) << 32; 71 size |= (u64) ntohl(*bp++) << 32;
72 bp++; /* spare 4 */ 72 bp++; /* spare 4 */
73 *_bp = bp; 73 *_bp = bp;
@@ -1748,3 +1748,156 @@ int afs_fs_get_volume_status(struct afs_server *server,
1748 1748
1749 return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode); 1749 return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
1750} 1750}
1751
1752/*
1753 * deliver reply data to an FS.SetLock, FS.ExtendLock or FS.ReleaseLock
1754 */
1755static int afs_deliver_fs_xxxx_lock(struct afs_call *call,
1756 struct sk_buff *skb, bool last)
1757{
1758 const __be32 *bp;
1759
1760 _enter("{%u},{%u},%d", call->unmarshall, skb->len, last);
1761
1762 afs_transfer_reply(call, skb);
1763 if (!last)
1764 return 0;
1765
1766 if (call->reply_size != call->reply_max)
1767 return -EBADMSG;
1768
1769 /* unmarshall the reply once we've received all of it */
1770 bp = call->buffer;
1771 /* xdr_decode_AFSVolSync(&bp, call->replyX); */
1772
1773 _leave(" = 0 [done]");
1774 return 0;
1775}
1776
1777/*
1778 * FS.SetLock operation type
1779 */
1780static const struct afs_call_type afs_RXFSSetLock = {
1781 .name = "FS.SetLock",
1782 .deliver = afs_deliver_fs_xxxx_lock,
1783 .abort_to_error = afs_abort_to_error,
1784 .destructor = afs_flat_call_destructor,
1785};
1786
1787/*
1788 * FS.ExtendLock operation type
1789 */
1790static const struct afs_call_type afs_RXFSExtendLock = {
1791 .name = "FS.ExtendLock",
1792 .deliver = afs_deliver_fs_xxxx_lock,
1793 .abort_to_error = afs_abort_to_error,
1794 .destructor = afs_flat_call_destructor,
1795};
1796
1797/*
1798 * FS.ReleaseLock operation type
1799 */
1800static const struct afs_call_type afs_RXFSReleaseLock = {
1801 .name = "FS.ReleaseLock",
1802 .deliver = afs_deliver_fs_xxxx_lock,
1803 .abort_to_error = afs_abort_to_error,
1804 .destructor = afs_flat_call_destructor,
1805};
1806
1807/*
1808 * get a lock on a file
1809 */
1810int afs_fs_set_lock(struct afs_server *server,
1811 struct key *key,
1812 struct afs_vnode *vnode,
1813 afs_lock_type_t type,
1814 const struct afs_wait_mode *wait_mode)
1815{
1816 struct afs_call *call;
1817 __be32 *bp;
1818
1819 _enter("");
1820
1821 call = afs_alloc_flat_call(&afs_RXFSSetLock, 5 * 4, 6 * 4);
1822 if (!call)
1823 return -ENOMEM;
1824
1825 call->key = key;
1826 call->reply = vnode;
1827 call->service_id = FS_SERVICE;
1828 call->port = htons(AFS_FS_PORT);
1829
1830 /* marshall the parameters */
1831 bp = call->request;
1832 *bp++ = htonl(FSSETLOCK);
1833 *bp++ = htonl(vnode->fid.vid);
1834 *bp++ = htonl(vnode->fid.vnode);
1835 *bp++ = htonl(vnode->fid.unique);
1836 *bp++ = htonl(type);
1837
1838 return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
1839}
1840
1841/*
1842 * extend a lock on a file
1843 */
1844int afs_fs_extend_lock(struct afs_server *server,
1845 struct key *key,
1846 struct afs_vnode *vnode,
1847 const struct afs_wait_mode *wait_mode)
1848{
1849 struct afs_call *call;
1850 __be32 *bp;
1851
1852 _enter("");
1853
1854 call = afs_alloc_flat_call(&afs_RXFSExtendLock, 4 * 4, 6 * 4);
1855 if (!call)
1856 return -ENOMEM;
1857
1858 call->key = key;
1859 call->reply = vnode;
1860 call->service_id = FS_SERVICE;
1861 call->port = htons(AFS_FS_PORT);
1862
1863 /* marshall the parameters */
1864 bp = call->request;
1865 *bp++ = htonl(FSEXTENDLOCK);
1866 *bp++ = htonl(vnode->fid.vid);
1867 *bp++ = htonl(vnode->fid.vnode);
1868 *bp++ = htonl(vnode->fid.unique);
1869
1870 return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
1871}
1872
1873/*
1874 * release a lock on a file
1875 */
1876int afs_fs_release_lock(struct afs_server *server,
1877 struct key *key,
1878 struct afs_vnode *vnode,
1879 const struct afs_wait_mode *wait_mode)
1880{
1881 struct afs_call *call;
1882 __be32 *bp;
1883
1884 _enter("");
1885
1886 call = afs_alloc_flat_call(&afs_RXFSReleaseLock, 4 * 4, 6 * 4);
1887 if (!call)
1888 return -ENOMEM;
1889
1890 call->key = key;
1891 call->reply = vnode;
1892 call->service_id = FS_SERVICE;
1893 call->port = htons(AFS_FS_PORT);
1894
1895 /* marshall the parameters */
1896 bp = call->request;
1897 *bp++ = htonl(FSRELEASELOCK);
1898 *bp++ = htonl(vnode->fid.vid);
1899 *bp++ = htonl(vnode->fid.vnode);
1900 *bp++ = htonl(vnode->fid.unique);
1901
1902 return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
1903}
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 2c55dd94a1de..6306438f331f 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -351,10 +351,18 @@ struct afs_vnode {
351#define AFS_VNODE_ZAP_DATA 3 /* set if vnode's data should be invalidated */ 351#define AFS_VNODE_ZAP_DATA 3 /* set if vnode's data should be invalidated */
352#define AFS_VNODE_DELETED 4 /* set if vnode deleted on server */ 352#define AFS_VNODE_DELETED 4 /* set if vnode deleted on server */
353#define AFS_VNODE_MOUNTPOINT 5 /* set if vnode is a mountpoint symlink */ 353#define AFS_VNODE_MOUNTPOINT 5 /* set if vnode is a mountpoint symlink */
354#define AFS_VNODE_LOCKING 6 /* set if waiting for lock on vnode */
355#define AFS_VNODE_READLOCKED 7 /* set if vnode is read-locked on the server */
356#define AFS_VNODE_WRITELOCKED 8 /* set if vnode is write-locked on the server */
357#define AFS_VNODE_UNLOCKING 9 /* set if vnode is being unlocked on the server */
354 358
355 long acl_order; /* ACL check count (callback break count) */ 359 long acl_order; /* ACL check count (callback break count) */
356 360
357 struct list_head writebacks; /* alterations in pagecache that need writing */ 361 struct list_head writebacks; /* alterations in pagecache that need writing */
362 struct list_head pending_locks; /* locks waiting to be granted */
363 struct list_head granted_locks; /* locks granted on this file */
364 struct delayed_work lock_work; /* work to be done in locking */
365 struct key *unlock_key; /* key to be used in unlocking */
358 366
359 /* outstanding callback notification on this file */ 367 /* outstanding callback notification on this file */
360 struct rb_node server_rb; /* link in server->fs_vnodes */ 368 struct rb_node server_rb; /* link in server->fs_vnodes */
@@ -474,6 +482,15 @@ extern int afs_open(struct inode *, struct file *);
474extern int afs_release(struct inode *, struct file *); 482extern int afs_release(struct inode *, struct file *);
475 483
476/* 484/*
485 * flock.c
486 */
487extern void __exit afs_kill_lock_manager(void);
488extern void afs_lock_work(struct work_struct *);
489extern void afs_lock_may_be_available(struct afs_vnode *);
490extern int afs_lock(struct file *, int, struct file_lock *);
491extern int afs_flock(struct file *, int, struct file_lock *);
492
493/*
477 * fsclient.c 494 * fsclient.c
478 */ 495 */
479extern int afs_fs_fetch_file_status(struct afs_server *, struct key *, 496extern int afs_fs_fetch_file_status(struct afs_server *, struct key *,
@@ -513,6 +530,15 @@ extern int afs_fs_get_volume_status(struct afs_server *, struct key *,
513 struct afs_vnode *, 530 struct afs_vnode *,
514 struct afs_volume_status *, 531 struct afs_volume_status *,
515 const struct afs_wait_mode *); 532 const struct afs_wait_mode *);
533extern int afs_fs_set_lock(struct afs_server *, struct key *,
534 struct afs_vnode *, afs_lock_type_t,
535 const struct afs_wait_mode *);
536extern int afs_fs_extend_lock(struct afs_server *, struct key *,
537 struct afs_vnode *,
538 const struct afs_wait_mode *);
539extern int afs_fs_release_lock(struct afs_server *, struct key *,
540 struct afs_vnode *,
541 const struct afs_wait_mode *);
516 542
517/* 543/*
518 * inode.c 544 * inode.c
@@ -681,6 +707,10 @@ extern int afs_vnode_store_data(struct afs_writeback *, pgoff_t, pgoff_t,
681extern int afs_vnode_setattr(struct afs_vnode *, struct key *, struct iattr *); 707extern int afs_vnode_setattr(struct afs_vnode *, struct key *, struct iattr *);
682extern int afs_vnode_get_volume_status(struct afs_vnode *, struct key *, 708extern int afs_vnode_get_volume_status(struct afs_vnode *, struct key *,
683 struct afs_volume_status *); 709 struct afs_volume_status *);
710extern int afs_vnode_set_lock(struct afs_vnode *, struct key *,
711 afs_lock_type_t);
712extern int afs_vnode_extend_lock(struct afs_vnode *, struct key *);
713extern int afs_vnode_release_lock(struct afs_vnode *, struct key *);
684 714
685/* 715/*
686 * volume.c 716 * volume.c
diff --git a/fs/afs/main.c b/fs/afs/main.c
index cd21195bbb24..0f60f6b35769 100644
--- a/fs/afs/main.c
+++ b/fs/afs/main.c
@@ -168,6 +168,7 @@ static void __exit afs_exit(void)
168 printk(KERN_INFO "kAFS: Red Hat AFS client v0.1 unregistering.\n"); 168 printk(KERN_INFO "kAFS: Red Hat AFS client v0.1 unregistering.\n");
169 169
170 afs_fs_exit(); 170 afs_fs_exit();
171 afs_kill_lock_manager();
171 afs_close_socket(); 172 afs_close_socket();
172 afs_purge_servers(); 173 afs_purge_servers();
173 afs_callback_update_kill(); 174 afs_callback_update_kill();
diff --git a/fs/afs/misc.c b/fs/afs/misc.c
index d1a889c40742..2d33a5f7d218 100644
--- a/fs/afs/misc.c
+++ b/fs/afs/misc.c
@@ -35,6 +35,7 @@ int afs_abort_to_error(u32 abort_code)
35 case VOVERQUOTA: return -EDQUOT; 35 case VOVERQUOTA: return -EDQUOT;
36 case VBUSY: return -EBUSY; 36 case VBUSY: return -EBUSY;
37 case VMOVED: return -ENXIO; 37 case VMOVED: return -ENXIO;
38 case 0x2f6df0a: return -EWOULDBLOCK;
38 case 0x2f6df0c: return -EACCES; 39 case 0x2f6df0c: return -EACCES;
39 case 0x2f6df0f: return -EBUSY; 40 case 0x2f6df0f: return -EBUSY;
40 case 0x2f6df10: return -EEXIST; 41 case 0x2f6df10: return -EEXIST;
diff --git a/fs/afs/super.c b/fs/afs/super.c
index 2e8496ba1205..993cdf1cce3a 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -460,6 +460,9 @@ static void afs_i_init_once(void *_vnode, struct kmem_cache *cachep,
460 spin_lock_init(&vnode->writeback_lock); 460 spin_lock_init(&vnode->writeback_lock);
461 spin_lock_init(&vnode->lock); 461 spin_lock_init(&vnode->lock);
462 INIT_LIST_HEAD(&vnode->writebacks); 462 INIT_LIST_HEAD(&vnode->writebacks);
463 INIT_LIST_HEAD(&vnode->pending_locks);
464 INIT_LIST_HEAD(&vnode->granted_locks);
465 INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);
463 INIT_WORK(&vnode->cb_broken_work, afs_broken_callback_work); 466 INIT_WORK(&vnode->cb_broken_work, afs_broken_callback_work);
464} 467}
465 468
diff --git a/fs/afs/vnode.c b/fs/afs/vnode.c
index 232c55dc245d..ac811e445b2d 100644
--- a/fs/afs/vnode.c
+++ b/fs/afs/vnode.c
@@ -887,11 +887,6 @@ int afs_vnode_get_volume_status(struct afs_vnode *vnode, struct key *key,
887 vnode->fid.unique, 887 vnode->fid.unique,
888 key_serial(key)); 888 key_serial(key));
889 889
890 /* this op will fetch the status */
891 spin_lock(&vnode->lock);
892 vnode->update_cnt++;
893 spin_unlock(&vnode->lock);
894
895 do { 890 do {
896 /* pick a server to query */ 891 /* pick a server to query */
897 server = afs_volume_pick_fileserver(vnode); 892 server = afs_volume_pick_fileserver(vnode);
@@ -905,20 +900,127 @@ int afs_vnode_get_volume_status(struct afs_vnode *vnode, struct key *key,
905 } while (!afs_volume_release_fileserver(vnode, server, ret)); 900 } while (!afs_volume_release_fileserver(vnode, server, ret));
906 901
907 /* adjust the flags */ 902 /* adjust the flags */
908 if (ret == 0) { 903 if (ret == 0)
909 afs_vnode_finalise_status_update(vnode, server); 904 afs_put_server(server);
905
906 _leave(" = %d", ret);
907 return ret;
908
909no_server:
910 return PTR_ERR(server);
911}
912
913/*
914 * get a lock on a file
915 */
916int afs_vnode_set_lock(struct afs_vnode *vnode, struct key *key,
917 afs_lock_type_t type)
918{
919 struct afs_server *server;
920 int ret;
921
922 _enter("%s{%x:%u.%u},%x,%u",
923 vnode->volume->vlocation->vldb.name,
924 vnode->fid.vid,
925 vnode->fid.vnode,
926 vnode->fid.unique,
927 key_serial(key), type);
928
929 do {
930 /* pick a server to query */
931 server = afs_volume_pick_fileserver(vnode);
932 if (IS_ERR(server))
933 goto no_server;
934
935 _debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
936
937 ret = afs_fs_set_lock(server, key, vnode, type, &afs_sync_call);
938
939 } while (!afs_volume_release_fileserver(vnode, server, ret));
940
941 /* adjust the flags */
942 if (ret == 0)
943 afs_put_server(server);
944
945 _leave(" = %d", ret);
946 return ret;
947
948no_server:
949 return PTR_ERR(server);
950}
951
952/*
953 * extend a lock on a file
954 */
955int afs_vnode_extend_lock(struct afs_vnode *vnode, struct key *key)
956{
957 struct afs_server *server;
958 int ret;
959
960 _enter("%s{%x:%u.%u},%x",
961 vnode->volume->vlocation->vldb.name,
962 vnode->fid.vid,
963 vnode->fid.vnode,
964 vnode->fid.unique,
965 key_serial(key));
966
967 do {
968 /* pick a server to query */
969 server = afs_volume_pick_fileserver(vnode);
970 if (IS_ERR(server))
971 goto no_server;
972
973 _debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
974
975 ret = afs_fs_extend_lock(server, key, vnode, &afs_sync_call);
976
977 } while (!afs_volume_release_fileserver(vnode, server, ret));
978
979 /* adjust the flags */
980 if (ret == 0)
981 afs_put_server(server);
982
983 _leave(" = %d", ret);
984 return ret;
985
986no_server:
987 return PTR_ERR(server);
988}
989
990/*
991 * release a lock on a file
992 */
993int afs_vnode_release_lock(struct afs_vnode *vnode, struct key *key)
994{
995 struct afs_server *server;
996 int ret;
997
998 _enter("%s{%x:%u.%u},%x",
999 vnode->volume->vlocation->vldb.name,
1000 vnode->fid.vid,
1001 vnode->fid.vnode,
1002 vnode->fid.unique,
1003 key_serial(key));
1004
1005 do {
1006 /* pick a server to query */
1007 server = afs_volume_pick_fileserver(vnode);
1008 if (IS_ERR(server))
1009 goto no_server;
1010
1011 _debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
1012
1013 ret = afs_fs_release_lock(server, key, vnode, &afs_sync_call);
1014
1015 } while (!afs_volume_release_fileserver(vnode, server, ret));
1016
1017 /* adjust the flags */
1018 if (ret == 0)
910 afs_put_server(server); 1019 afs_put_server(server);
911 } else {
912 afs_vnode_status_update_failed(vnode, ret);
913 }
914 1020
915 _leave(" = %d", ret); 1021 _leave(" = %d", ret);
916 return ret; 1022 return ret;
917 1023
918no_server: 1024no_server:
919 spin_lock(&vnode->lock);
920 vnode->update_cnt--;
921 ASSERTCMP(vnode->update_cnt, >=, 0);
922 spin_unlock(&vnode->lock);
923 return PTR_ERR(server); 1025 return PTR_ERR(server);
924} 1026}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 51c938a71dec..aa4530c1ff7a 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -820,6 +820,10 @@ struct file_lock {
820 union { 820 union {
821 struct nfs_lock_info nfs_fl; 821 struct nfs_lock_info nfs_fl;
822 struct nfs4_lock_info nfs4_fl; 822 struct nfs4_lock_info nfs4_fl;
823 struct {
824 struct list_head link; /* link in AFS vnode's pending_locks list */
825 int state; /* state of grant or error if -ve */
826 } afs;
823 } fl_u; 827 } fl_u;
824}; 828};
825 829