blob: e577a78d7bacf9e07d3cb50f4bb657d30d5e9446 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/lockd/svclock.c
3 *
4 * Handling of server-side locks, mostly of the blocked variety.
5 * This is the ugliest part of lockd because we tread on very thin ice.
6 * GRANT and CANCEL calls may get stuck, meet in mid-flight, etc.
7 * IMNSHO introducing the grant callback into the NLM protocol was one
8 * of the worst ideas Sun ever had. Except maybe for the idea of doing
9 * NFS file locking at all.
10 *
11 * I'm trying hard to avoid race conditions by protecting most accesses
12 * to a file's list of blocked locks through a semaphore. The global
13 * list of blocked locks is not protected in this fashion however.
14 * Therefore, some functions (such as the RPC callback for the async grant
15 * call) move blocked locks towards the head of the list *while some other
16 * process might be traversing it*. This should not be a problem in
17 * practice, because this will only cause functions traversing the list
18 * to visit some blocks twice.
19 *
20 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
21 */
22
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/types.h>
24#include <linux/errno.h>
25#include <linux/kernel.h>
26#include <linux/sched.h>
27#include <linux/smp_lock.h>
28#include <linux/sunrpc/clnt.h>
29#include <linux/sunrpc/svc.h>
30#include <linux/lockd/nlm.h>
31#include <linux/lockd/lockd.h>
Jeff Laytond751a7c2008-02-07 16:34:55 -050032#include <linux/kthread.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34#define NLMDBG_FACILITY NLMDBG_SVCLOCK
35
36#ifdef CONFIG_LOCKD_V4
37#define nlm_deadlock nlm4_deadlock
38#else
39#define nlm_deadlock nlm_lck_denied
40#endif
41
Trond Myklebust6849c0c2006-03-20 13:44:39 -050042static void nlmsvc_release_block(struct nlm_block *block);
Linus Torvalds1da177e2005-04-16 15:20:36 -070043static void nlmsvc_insert_block(struct nlm_block *block, unsigned long);
Olaf Kirch68a2d762006-10-04 02:15:57 -070044static void nlmsvc_remove_block(struct nlm_block *block);
Trond Myklebust963d8fe2006-01-03 09:55:04 +010045
Trond Myklebust5e1abf82006-03-20 13:44:39 -050046static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock);
47static void nlmsvc_freegrantargs(struct nlm_rqst *call);
Trond Myklebust963d8fe2006-01-03 09:55:04 +010048static const struct rpc_call_ops nlmsvc_grant_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
50/*
51 * The list of blocked locks to retry
52 */
Olaf Kirch68a2d762006-10-04 02:15:57 -070053static LIST_HEAD(nlm_blocked);
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
55/*
56 * Insert a blocked lock into the global list
57 */
58static void
59nlmsvc_insert_block(struct nlm_block *block, unsigned long when)
60{
Olaf Kirch68a2d762006-10-04 02:15:57 -070061 struct nlm_block *b;
62 struct list_head *pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
64 dprintk("lockd: nlmsvc_insert_block(%p, %ld)\n", block, when);
Olaf Kirch68a2d762006-10-04 02:15:57 -070065 if (list_empty(&block->b_list)) {
66 kref_get(&block->b_count);
67 } else {
68 list_del_init(&block->b_list);
69 }
70
71 pos = &nlm_blocked;
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 if (when != NLM_NEVER) {
73 if ((when += jiffies) == NLM_NEVER)
74 when ++;
Olaf Kirch68a2d762006-10-04 02:15:57 -070075 list_for_each(pos, &nlm_blocked) {
76 b = list_entry(pos, struct nlm_block, b_list);
77 if (time_after(b->b_when,when) || b->b_when == NLM_NEVER)
78 break;
79 }
80 /* On normal exit from the loop, pos == &nlm_blocked,
81 * so we will be adding to the end of the list - good
82 */
83 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
Olaf Kirch68a2d762006-10-04 02:15:57 -070085 list_add_tail(&block->b_list, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 block->b_when = when;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087}
88
89/*
90 * Remove a block from the global list
91 */
Olaf Kirch68a2d762006-10-04 02:15:57 -070092static inline void
Linus Torvalds1da177e2005-04-16 15:20:36 -070093nlmsvc_remove_block(struct nlm_block *block)
94{
Olaf Kirch68a2d762006-10-04 02:15:57 -070095 if (!list_empty(&block->b_list)) {
96 list_del_init(&block->b_list);
97 nlmsvc_release_block(block);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070099}
100
101/*
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500102 * Find a block for a given lock
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 */
104static struct nlm_block *
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500105nlmsvc_lookup_block(struct nlm_file *file, struct nlm_lock *lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106{
Olaf Kirch68a2d762006-10-04 02:15:57 -0700107 struct nlm_block *block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 struct file_lock *fl;
109
110 dprintk("lockd: nlmsvc_lookup_block f=%p pd=%d %Ld-%Ld ty=%d\n",
111 file, lock->fl.fl_pid,
112 (long long)lock->fl.fl_start,
113 (long long)lock->fl.fl_end, lock->fl.fl_type);
Olaf Kirch68a2d762006-10-04 02:15:57 -0700114 list_for_each_entry(block, &nlm_blocked, b_list) {
Trond Myklebust92737232006-03-20 13:44:45 -0500115 fl = &block->b_call->a_args.lock.fl;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 dprintk("lockd: check f=%p pd=%d %Ld-%Ld ty=%d cookie=%s\n",
117 block->b_file, fl->fl_pid,
118 (long long)fl->fl_start,
119 (long long)fl->fl_end, fl->fl_type,
Trond Myklebust92737232006-03-20 13:44:45 -0500120 nlmdbg_cookie2a(&block->b_call->a_args.cookie));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 if (block->b_file == file && nlm_compare_locks(fl, &lock->fl)) {
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500122 kref_get(&block->b_count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 return block;
124 }
125 }
126
127 return NULL;
128}
129
130static inline int nlm_cookie_match(struct nlm_cookie *a, struct nlm_cookie *b)
131{
J. Bruce Fields6d7bbbb2008-07-15 14:38:32 -0400132 if (a->len != b->len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 return 0;
J. Bruce Fields6d7bbbb2008-07-15 14:38:32 -0400134 if (memcmp(a->data, b->data, a->len))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 return 0;
136 return 1;
137}
138
139/*
140 * Find a block with a given NLM cookie.
141 */
142static inline struct nlm_block *
Olaf Kirch39be4502006-10-04 02:16:03 -0700143nlmsvc_find_block(struct nlm_cookie *cookie)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144{
145 struct nlm_block *block;
146
Olaf Kirch68a2d762006-10-04 02:15:57 -0700147 list_for_each_entry(block, &nlm_blocked, b_list) {
Olaf Kirch39be4502006-10-04 02:16:03 -0700148 if (nlm_cookie_match(&block->b_call->a_args.cookie,cookie))
Olaf Kirch68a2d762006-10-04 02:15:57 -0700149 goto found;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 }
151
Olaf Kirch68a2d762006-10-04 02:15:57 -0700152 return NULL;
153
154found:
Olaf Kirch39be4502006-10-04 02:16:03 -0700155 dprintk("nlmsvc_find_block(%s): block=%p\n", nlmdbg_cookie2a(cookie), block);
Olaf Kirch68a2d762006-10-04 02:15:57 -0700156 kref_get(&block->b_count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 return block;
158}
159
160/*
161 * Create a block and initialize it.
162 *
163 * Note: we explicitly set the cookie of the grant reply to that of
164 * the blocked lock request. The spec explicitly mentions that the client
165 * should _not_ rely on the callback containing the same cookie as the
166 * request, but (as I found out later) that's because some implementations
167 * do just this. Never mind the standards comittees, they support our
168 * logging industries.
Olaf Kirch39be4502006-10-04 02:16:03 -0700169 *
170 * 10 years later: I hope we can safely ignore these old and broken
171 * clients by now. Let's fix this so we can uniquely identify an incoming
172 * GRANTED_RES message by cookie, without having to rely on the client's IP
173 * address. --okir
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 */
Trond Myklebust255129d2007-09-25 15:55:03 -0400175static struct nlm_block *
176nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_host *host,
177 struct nlm_file *file, struct nlm_lock *lock,
178 struct nlm_cookie *cookie)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179{
180 struct nlm_block *block;
Trond Myklebust92737232006-03-20 13:44:45 -0500181 struct nlm_rqst *call = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
J. Bruce Fields560de0e2008-07-15 15:05:45 -0400183 nlm_get_host(host);
Trond Myklebust92737232006-03-20 13:44:45 -0500184 call = nlm_alloc_call(host);
185 if (call == NULL)
186 return NULL;
187
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 /* Allocate memory for block, and initialize arguments */
Trond Myklebust92737232006-03-20 13:44:45 -0500189 block = kzalloc(sizeof(*block), GFP_KERNEL);
190 if (block == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 goto failed;
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500192 kref_init(&block->b_count);
Olaf Kirch68a2d762006-10-04 02:15:57 -0700193 INIT_LIST_HEAD(&block->b_list);
194 INIT_LIST_HEAD(&block->b_flist);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195
Trond Myklebust92737232006-03-20 13:44:45 -0500196 if (!nlmsvc_setgrantargs(call, lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 goto failed_free;
198
199 /* Set notifier function for VFS, and init args */
Trond Myklebust92737232006-03-20 13:44:45 -0500200 call->a_args.lock.fl.fl_flags |= FL_SLEEP;
201 call->a_args.lock.fl.fl_lmops = &nlmsvc_lock_operations;
Olaf Kirch39be4502006-10-04 02:16:03 -0700202 nlmclnt_next_cookie(&call->a_args.cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203
204 dprintk("lockd: created block %p...\n", block);
205
206 /* Create and initialize the block */
207 block->b_daemon = rqstp->rq_server;
208 block->b_host = host;
209 block->b_file = file;
Marc Eshel5ea0d752006-11-28 16:27:06 -0500210 block->b_fl = NULL;
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500211 file->f_count++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212
213 /* Add to file's list of blocks */
Olaf Kirch68a2d762006-10-04 02:15:57 -0700214 list_add(&block->b_flist, &file->f_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
216 /* Set up RPC arguments for callback */
Trond Myklebust92737232006-03-20 13:44:45 -0500217 block->b_call = call;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 call->a_flags = RPC_TASK_ASYNC;
Trond Myklebust92737232006-03-20 13:44:45 -0500219 call->a_block = block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220
221 return block;
222
223failed_free:
224 kfree(block);
225failed:
Trond Myklebust92737232006-03-20 13:44:45 -0500226 nlm_release_call(call);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 return NULL;
228}
229
230/*
J. Bruce Fields3c61eec2008-04-07 13:05:27 -0400231 * Delete a block.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 * It is the caller's responsibility to check whether the file
233 * can be closed hereafter.
234 */
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500235static int nlmsvc_unlink_block(struct nlm_block *block)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236{
Trond Myklebust09c79382006-03-20 13:44:38 -0500237 int status;
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500238 dprintk("lockd: unlinking block %p...\n", block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239
240 /* Remove block from list */
Trond Myklebust92737232006-03-20 13:44:45 -0500241 status = posix_unblock_lock(block->b_file->f_file, &block->b_call->a_args.lock.fl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 nlmsvc_remove_block(block);
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500243 return status;
244}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500246static void nlmsvc_free_block(struct kref *kref)
247{
248 struct nlm_block *block = container_of(kref, struct nlm_block, b_count);
249 struct nlm_file *file = block->b_file;
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500250
251 dprintk("lockd: freeing block %p...\n", block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252
253 /* Remove block from file's list of blocks */
Neil Brown89e63ef2006-10-04 02:16:06 -0700254 mutex_lock(&file->f_mutex);
Olaf Kirch68a2d762006-10-04 02:15:57 -0700255 list_del_init(&block->b_flist);
Neil Brown89e63ef2006-10-04 02:16:06 -0700256 mutex_unlock(&file->f_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
Trond Myklebust92737232006-03-20 13:44:45 -0500258 nlmsvc_freegrantargs(block->b_call);
259 nlm_release_call(block->b_call);
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500260 nlm_release_file(block->b_file);
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500261 kfree(block->b_fl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 kfree(block);
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500263}
264
265static void nlmsvc_release_block(struct nlm_block *block)
266{
267 if (block != NULL)
268 kref_put(&block->b_count, nlmsvc_free_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269}
270
Olaf Kirchf2af7932006-10-04 02:15:59 -0700271/*
272 * Loop over all blocks and delete blocks held by
273 * a matching host.
274 */
275void nlmsvc_traverse_blocks(struct nlm_host *host,
276 struct nlm_file *file,
277 nlm_host_match_fn_t match)
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500278{
Olaf Kirch68a2d762006-10-04 02:15:57 -0700279 struct nlm_block *block, *next;
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500280
281restart:
Neil Brown89e63ef2006-10-04 02:16:06 -0700282 mutex_lock(&file->f_mutex);
Olaf Kirch68a2d762006-10-04 02:15:57 -0700283 list_for_each_entry_safe(block, next, &file->f_blocks, b_flist) {
Olaf Kirchf2af7932006-10-04 02:15:59 -0700284 if (!match(block->b_host, host))
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500285 continue;
Olaf Kirch68a2d762006-10-04 02:15:57 -0700286 /* Do not destroy blocks that are not on
287 * the global retry list - why? */
288 if (list_empty(&block->b_list))
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500289 continue;
290 kref_get(&block->b_count);
Neil Brown89e63ef2006-10-04 02:16:06 -0700291 mutex_unlock(&file->f_mutex);
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500292 nlmsvc_unlink_block(block);
293 nlmsvc_release_block(block);
294 goto restart;
295 }
Neil Brown89e63ef2006-10-04 02:16:06 -0700296 mutex_unlock(&file->f_mutex);
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500297}
298
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299/*
Trond Myklebust5e1abf82006-03-20 13:44:39 -0500300 * Initialize arguments for GRANTED call. The nlm_rqst structure
301 * has been cleared already.
302 */
303static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock)
304{
305 locks_copy_lock(&call->a_args.lock.fl, &lock->fl);
306 memcpy(&call->a_args.lock.fh, &lock->fh, sizeof(call->a_args.lock.fh));
Serge E. Hallyne9ff3992006-10-02 02:18:11 -0700307 call->a_args.lock.caller = utsname()->nodename;
Trond Myklebust5e1abf82006-03-20 13:44:39 -0500308 call->a_args.lock.oh.len = lock->oh.len;
309
310 /* set default data area */
311 call->a_args.lock.oh.data = call->a_owner;
312 call->a_args.lock.svid = lock->fl.fl_pid;
313
314 if (lock->oh.len > NLMCLNT_OHSIZE) {
315 void *data = kmalloc(lock->oh.len, GFP_KERNEL);
Trond Myklebust92737232006-03-20 13:44:45 -0500316 if (!data)
Trond Myklebust5e1abf82006-03-20 13:44:39 -0500317 return 0;
Trond Myklebust5e1abf82006-03-20 13:44:39 -0500318 call->a_args.lock.oh.data = (u8 *) data;
319 }
320
321 memcpy(call->a_args.lock.oh.data, lock->oh.data, lock->oh.len);
322 return 1;
323}
324
325static void nlmsvc_freegrantargs(struct nlm_rqst *call)
326{
Trond Myklebust92737232006-03-20 13:44:45 -0500327 if (call->a_args.lock.oh.data != call->a_owner)
Trond Myklebust5e1abf82006-03-20 13:44:39 -0500328 kfree(call->a_args.lock.oh.data);
Felix Blyakhera9e61e22009-03-31 15:12:56 -0500329
330 locks_release_private(&call->a_args.lock.fl);
Trond Myklebust5e1abf82006-03-20 13:44:39 -0500331}
332
333/*
Marc Eshel2b36f412006-11-28 16:26:47 -0500334 * Deferred lock request handling for non-blocking lock
335 */
Al Viroca5c8cd2007-07-26 17:33:49 +0100336static __be32
Marc Eshel2b36f412006-11-28 16:26:47 -0500337nlmsvc_defer_lock_rqst(struct svc_rqst *rqstp, struct nlm_block *block)
338{
Al Viroca5c8cd2007-07-26 17:33:49 +0100339 __be32 status = nlm_lck_denied_nolocks;
Marc Eshel2b36f412006-11-28 16:26:47 -0500340
341 block->b_flags |= B_QUEUED;
342
343 nlmsvc_insert_block(block, NLM_TIMEOUT);
344
345 block->b_cache_req = &rqstp->rq_chandle;
346 if (rqstp->rq_chandle.defer) {
347 block->b_deferred_req =
348 rqstp->rq_chandle.defer(block->b_cache_req);
349 if (block->b_deferred_req != NULL)
350 status = nlm_drop_reply;
351 }
352 dprintk("lockd: nlmsvc_defer_lock_rqst block %p flags %d status %d\n",
Al Viroca5c8cd2007-07-26 17:33:49 +0100353 block, block->b_flags, ntohl(status));
Marc Eshel2b36f412006-11-28 16:26:47 -0500354
355 return status;
356}
357
358/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 * Attempt to establish a lock, and if it can't be granted, block it
360 * if required.
361 */
Al Viro52921e02006-10-19 23:28:46 -0700362__be32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file,
Jeff Layton6cde4de2008-07-15 14:26:17 -0400364 struct nlm_host *host, struct nlm_lock *lock, int wait,
J. Bruce Fieldsb2b50282008-02-06 13:59:23 -0500365 struct nlm_cookie *cookie, int reclaim)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366{
Marc Eshelf8120482006-12-05 23:48:10 -0500367 struct nlm_block *block = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 int error;
Al Viro52921e02006-10-19 23:28:46 -0700369 __be32 ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370
371 dprintk("lockd: nlmsvc_lock(%s/%ld, ty=%d, pi=%d, %Ld-%Ld, bl=%d)\n",
Josef Sipek225a7192006-12-08 02:37:18 -0800372 file->f_file->f_path.dentry->d_inode->i_sb->s_id,
373 file->f_file->f_path.dentry->d_inode->i_ino,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 lock->fl.fl_type, lock->fl.fl_pid,
375 (long long)lock->fl.fl_start,
376 (long long)lock->fl.fl_end,
377 wait);
378
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 /* Lock file against concurrent access */
Neil Brown89e63ef2006-10-04 02:16:06 -0700380 mutex_lock(&file->f_mutex);
Marc Eshelf8120482006-12-05 23:48:10 -0500381 /* Get existing block (in case client is busy-waiting)
382 * or create new block
383 */
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500384 block = nlmsvc_lookup_block(file, lock);
Trond Myklebust09c79382006-03-20 13:44:38 -0500385 if (block == NULL) {
J. Bruce Fields560de0e2008-07-15 15:05:45 -0400386 block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
Marc Eshelf8120482006-12-05 23:48:10 -0500387 ret = nlm_lck_denied_nolocks;
388 if (block == NULL)
389 goto out;
Trond Myklebust92737232006-03-20 13:44:45 -0500390 lock = &block->b_call->a_args.lock;
Marc Eshelf8120482006-12-05 23:48:10 -0500391 } else
392 lock->fl.fl_flags &= ~FL_SLEEP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393
Marc Eshel1a8322b2006-11-28 16:27:06 -0500394 if (block->b_flags & B_QUEUED) {
395 dprintk("lockd: nlmsvc_lock deferred block %p flags %d\n",
396 block, block->b_flags);
397 if (block->b_granted) {
398 nlmsvc_unlink_block(block);
399 ret = nlm_granted;
400 goto out;
401 }
402 if (block->b_flags & B_TIMED_OUT) {
403 nlmsvc_unlink_block(block);
404 ret = nlm_lck_denied;
405 goto out;
406 }
407 ret = nlm_drop_reply;
408 goto out;
409 }
410
J. Bruce Fieldsb2b50282008-02-06 13:59:23 -0500411 if (locks_in_grace() && !reclaim) {
412 ret = nlm_lck_denied_grace_period;
413 goto out;
414 }
J. Bruce Fieldsd22b1cf2008-02-06 15:05:12 -0500415 if (reclaim && !locks_in_grace()) {
416 ret = nlm_lck_denied_grace_period;
417 goto out;
418 }
J. Bruce Fieldsb2b50282008-02-06 13:59:23 -0500419
Marc Eshel1a8322b2006-11-28 16:27:06 -0500420 if (!wait)
421 lock->fl.fl_flags &= ~FL_SLEEP;
422 error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL);
Trond Myklebust09c79382006-03-20 13:44:38 -0500423 lock->fl.fl_flags &= ~FL_SLEEP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424
Marc Eshel1a8322b2006-11-28 16:27:06 -0500425 dprintk("lockd: vfs_lock_file returned %d\n", error);
J. Bruce Fields6d7bbbb2008-07-15 14:38:32 -0400426 switch (error) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 case 0:
Andy Adamson15dadef2006-03-20 13:44:24 -0500428 ret = nlm_granted;
429 goto out;
Trond Myklebust09c79382006-03-20 13:44:38 -0500430 case -EAGAIN:
Miklos Szeredie33d1ea2009-02-09 12:30:43 -0500431 /*
432 * If this is a blocking request for an
433 * already pending lock request then we need
434 * to put it back on lockd's block list
435 */
436 if (wait)
437 break;
Marc Eshel1a8322b2006-11-28 16:27:06 -0500438 ret = nlm_lck_denied;
Miklos Szeredie33d1ea2009-02-09 12:30:43 -0500439 goto out;
Miklos Szeredibde74e42008-07-25 01:48:57 -0700440 case FILE_LOCK_DEFERRED:
Marc Eshel1a8322b2006-11-28 16:27:06 -0500441 if (wait)
442 break;
443 /* Filesystem lock operation is in progress
444 Add it to the queue waiting for callback */
445 ret = nlmsvc_defer_lock_rqst(rqstp, block);
446 goto out;
Trond Myklebust09c79382006-03-20 13:44:38 -0500447 case -EDEADLK:
Andy Adamson15dadef2006-03-20 13:44:24 -0500448 ret = nlm_deadlock;
449 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450 default: /* includes ENOLCK */
Andy Adamson15dadef2006-03-20 13:44:24 -0500451 ret = nlm_lck_denied_nolocks;
452 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 }
454
Trond Myklebust09c79382006-03-20 13:44:38 -0500455 ret = nlm_lck_blocked;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456
457 /* Append to list of blocked */
Marc Eshelf8120482006-12-05 23:48:10 -0500458 nlmsvc_insert_block(block, NLM_NEVER);
Andy Adamson15dadef2006-03-20 13:44:24 -0500459out:
Neil Brown89e63ef2006-10-04 02:16:06 -0700460 mutex_unlock(&file->f_mutex);
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500461 nlmsvc_release_block(block);
Andy Adamson15dadef2006-03-20 13:44:24 -0500462 dprintk("lockd: nlmsvc_lock returned %u\n", ret);
463 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464}
465
466/*
467 * Test for presence of a conflicting lock.
468 */
Al Viro52921e02006-10-19 23:28:46 -0700469__be32
Marc Eshel85f3f1b32006-11-28 16:27:06 -0500470nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
Jeff Layton8f920d52008-07-15 14:06:48 -0400471 struct nlm_host *host, struct nlm_lock *lock,
472 struct nlm_lock *conflock, struct nlm_cookie *cookie)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473{
Marc Eshel5ea0d752006-11-28 16:27:06 -0500474 struct nlm_block *block = NULL;
475 int error;
476 __be32 ret;
477
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 dprintk("lockd: nlmsvc_testlock(%s/%ld, ty=%d, %Ld-%Ld)\n",
Josef Sipek225a7192006-12-08 02:37:18 -0800479 file->f_file->f_path.dentry->d_inode->i_sb->s_id,
480 file->f_file->f_path.dentry->d_inode->i_ino,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 lock->fl.fl_type,
482 (long long)lock->fl.fl_start,
483 (long long)lock->fl.fl_end);
484
Marc Eshel5ea0d752006-11-28 16:27:06 -0500485 /* Get existing block (in case client is busy-waiting) */
486 block = nlmsvc_lookup_block(file, lock);
487
488 if (block == NULL) {
489 struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
490
491 if (conf == NULL)
492 return nlm_granted;
Trond Myklebust255129d2007-09-25 15:55:03 -0400493 block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
Marc Eshel5ea0d752006-11-28 16:27:06 -0500494 if (block == NULL) {
495 kfree(conf);
496 return nlm_granted;
497 }
498 block->b_fl = conf;
499 }
500 if (block->b_flags & B_QUEUED) {
501 dprintk("lockd: nlmsvc_testlock deferred block %p flags %d fl %p\n",
502 block, block->b_flags, block->b_fl);
503 if (block->b_flags & B_TIMED_OUT) {
504 nlmsvc_unlink_block(block);
Oleg Drokin29dbf542007-11-29 14:02:21 -0500505 ret = nlm_lck_denied;
506 goto out;
Marc Eshel5ea0d752006-11-28 16:27:06 -0500507 }
508 if (block->b_flags & B_GOT_CALLBACK) {
Oleg Drokin54ca95e2008-01-11 21:57:35 -0500509 nlmsvc_unlink_block(block);
Marc Eshel5ea0d752006-11-28 16:27:06 -0500510 if (block->b_fl != NULL
511 && block->b_fl->fl_type != F_UNLCK) {
512 lock->fl = *block->b_fl;
513 goto conf_lock;
Oleg Drokin29dbf542007-11-29 14:02:21 -0500514 } else {
Oleg Drokin29dbf542007-11-29 14:02:21 -0500515 ret = nlm_granted;
516 goto out;
Marc Eshel5ea0d752006-11-28 16:27:06 -0500517 }
518 }
Oleg Drokin29dbf542007-11-29 14:02:21 -0500519 ret = nlm_drop_reply;
520 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 }
522
J. Bruce Fieldsb2b50282008-02-06 13:59:23 -0500523 if (locks_in_grace()) {
524 ret = nlm_lck_denied_grace_period;
525 goto out;
526 }
Marc Eshel5ea0d752006-11-28 16:27:06 -0500527 error = vfs_test_lock(file->f_file, &lock->fl);
Miklos Szeredibde74e42008-07-25 01:48:57 -0700528 if (error == FILE_LOCK_DEFERRED) {
Oleg Drokin29dbf542007-11-29 14:02:21 -0500529 ret = nlmsvc_defer_lock_rqst(rqstp, block);
530 goto out;
531 }
Marc Eshel5ea0d752006-11-28 16:27:06 -0500532 if (error) {
533 ret = nlm_lck_denied_nolocks;
534 goto out;
535 }
536 if (lock->fl.fl_type == F_UNLCK) {
537 ret = nlm_granted;
538 goto out;
539 }
540
541conf_lock:
542 dprintk("lockd: conflicting lock(ty=%d, %Ld-%Ld)\n",
543 lock->fl.fl_type, (long long)lock->fl.fl_start,
544 (long long)lock->fl.fl_end);
545 conflock->caller = "somehost"; /* FIXME */
546 conflock->len = strlen(conflock->caller);
547 conflock->oh.len = 0; /* don't return OH info */
548 conflock->svid = lock->fl.fl_pid;
549 conflock->fl.fl_type = lock->fl.fl_type;
550 conflock->fl.fl_start = lock->fl.fl_start;
551 conflock->fl.fl_end = lock->fl.fl_end;
552 ret = nlm_lck_denied;
553out:
554 if (block)
555 nlmsvc_release_block(block);
556 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557}
558
559/*
560 * Remove a lock.
561 * This implies a CANCEL call: We send a GRANT_MSG, the client replies
562 * with a GRANT_RES call which gets lost, and calls UNLOCK immediately
563 * afterwards. In this case the block will still be there, and hence
564 * must be removed.
565 */
Al Viro52921e02006-10-19 23:28:46 -0700566__be32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567nlmsvc_unlock(struct nlm_file *file, struct nlm_lock *lock)
568{
569 int error;
570
571 dprintk("lockd: nlmsvc_unlock(%s/%ld, pi=%d, %Ld-%Ld)\n",
Josef Sipek225a7192006-12-08 02:37:18 -0800572 file->f_file->f_path.dentry->d_inode->i_sb->s_id,
573 file->f_file->f_path.dentry->d_inode->i_ino,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 lock->fl.fl_pid,
575 (long long)lock->fl.fl_start,
576 (long long)lock->fl.fl_end);
577
578 /* First, cancel any lock that might be there */
579 nlmsvc_cancel_blocked(file, lock);
580
581 lock->fl.fl_type = F_UNLCK;
Marc Eshel1a8322b2006-11-28 16:27:06 -0500582 error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583
584 return (error < 0)? nlm_lck_denied_nolocks : nlm_granted;
585}
586
587/*
588 * Cancel a previously blocked request.
589 *
590 * A cancel request always overrides any grant that may currently
591 * be in progress.
592 * The calling procedure must check whether the file can be closed.
593 */
Al Viro52921e02006-10-19 23:28:46 -0700594__be32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595nlmsvc_cancel_blocked(struct nlm_file *file, struct nlm_lock *lock)
596{
597 struct nlm_block *block;
J. Bruce Fields64a318e2006-01-03 09:55:46 +0100598 int status = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599
600 dprintk("lockd: nlmsvc_cancel(%s/%ld, pi=%d, %Ld-%Ld)\n",
Josef Sipek225a7192006-12-08 02:37:18 -0800601 file->f_file->f_path.dentry->d_inode->i_sb->s_id,
602 file->f_file->f_path.dentry->d_inode->i_ino,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 lock->fl.fl_pid,
604 (long long)lock->fl.fl_start,
605 (long long)lock->fl.fl_end);
606
J. Bruce Fieldsb2b50282008-02-06 13:59:23 -0500607 if (locks_in_grace())
608 return nlm_lck_denied_grace_period;
609
Neil Brown89e63ef2006-10-04 02:16:06 -0700610 mutex_lock(&file->f_mutex);
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500611 block = nlmsvc_lookup_block(file, lock);
Neil Brown89e63ef2006-10-04 02:16:06 -0700612 mutex_unlock(&file->f_mutex);
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500613 if (block != NULL) {
Marc Eshel1a8322b2006-11-28 16:27:06 -0500614 vfs_cancel_lock(block->b_file->f_file,
615 &block->b_call->a_args.lock.fl);
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500616 status = nlmsvc_unlink_block(block);
617 nlmsvc_release_block(block);
618 }
J. Bruce Fields64a318e2006-01-03 09:55:46 +0100619 return status ? nlm_lck_denied : nlm_granted;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620}
621
622/*
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500623 * This is a callback from the filesystem for VFS file lock requests.
624 * It will be used if fl_grant is defined and the filesystem can not
625 * respond to the request immediately.
626 * For GETLK request it will copy the reply to the nlm_block.
627 * For SETLK or SETLKW request it will get the local posix lock.
628 * In all cases it will move the block to the head of nlm_blocked q where
629 * nlmsvc_retry_blocked() can send back a reply for SETLKW or revisit the
630 * deferred rpc for GETLK and SETLK.
631 */
632static void
633nlmsvc_update_deferred_block(struct nlm_block *block, struct file_lock *conf,
634 int result)
635{
636 block->b_flags |= B_GOT_CALLBACK;
637 if (result == 0)
638 block->b_granted = 1;
639 else
640 block->b_flags |= B_TIMED_OUT;
641 if (conf) {
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500642 if (block->b_fl)
J. Bruce Fields1a747ee2008-04-24 10:08:22 -0400643 __locks_copy_lock(block->b_fl, conf);
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500644 }
645}
646
647static int nlmsvc_grant_deferred(struct file_lock *fl, struct file_lock *conf,
648 int result)
649{
650 struct nlm_block *block;
651 int rc = -ENOENT;
652
653 lock_kernel();
654 list_for_each_entry(block, &nlm_blocked, b_list) {
655 if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) {
656 dprintk("lockd: nlmsvc_notify_blocked block %p flags %d\n",
657 block, block->b_flags);
658 if (block->b_flags & B_QUEUED) {
659 if (block->b_flags & B_TIMED_OUT) {
660 rc = -ENOLCK;
661 break;
662 }
663 nlmsvc_update_deferred_block(block, conf, result);
664 } else if (result == 0)
665 block->b_granted = 1;
666
667 nlmsvc_insert_block(block, 0);
668 svc_wake_up(block->b_daemon);
669 rc = 0;
670 break;
671 }
672 }
673 unlock_kernel();
674 if (rc == -ENOENT)
675 printk(KERN_WARNING "lockd: grant for unknown block\n");
676 return rc;
677}
678
679/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 * Unblock a blocked lock request. This is a callback invoked from the
681 * VFS layer when a lock on which we blocked is removed.
682 *
683 * This function doesn't grant the blocked lock instantly, but rather moves
684 * the block to the head of nlm_blocked where it can be picked up by lockd.
685 */
686static void
687nlmsvc_notify_blocked(struct file_lock *fl)
688{
Olaf Kirch68a2d762006-10-04 02:15:57 -0700689 struct nlm_block *block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690
691 dprintk("lockd: VFS unblock notification for block %p\n", fl);
Olaf Kirch68a2d762006-10-04 02:15:57 -0700692 list_for_each_entry(block, &nlm_blocked, b_list) {
Trond Myklebust92737232006-03-20 13:44:45 -0500693 if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 nlmsvc_insert_block(block, 0);
695 svc_wake_up(block->b_daemon);
696 return;
697 }
698 }
699
700 printk(KERN_WARNING "lockd: notification for unknown block!\n");
701}
702
703static int nlmsvc_same_owner(struct file_lock *fl1, struct file_lock *fl2)
704{
705 return fl1->fl_owner == fl2->fl_owner && fl1->fl_pid == fl2->fl_pid;
706}
707
708struct lock_manager_operations nlmsvc_lock_operations = {
709 .fl_compare_owner = nlmsvc_same_owner,
710 .fl_notify = nlmsvc_notify_blocked,
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500711 .fl_grant = nlmsvc_grant_deferred,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712};
713
714/*
715 * Try to claim a lock that was previously blocked.
716 *
717 * Note that we use both the RPC_GRANTED_MSG call _and_ an async
718 * RPC thread when notifying the client. This seems like overkill...
719 * Here's why:
720 * - we don't want to use a synchronous RPC thread, otherwise
721 * we might find ourselves hanging on a dead portmapper.
722 * - Some lockd implementations (e.g. HP) don't react to
723 * RPC_GRANTED calls; they seem to insist on RPC_GRANTED_MSG calls.
724 */
725static void
726nlmsvc_grant_blocked(struct nlm_block *block)
727{
728 struct nlm_file *file = block->b_file;
Trond Myklebust92737232006-03-20 13:44:45 -0500729 struct nlm_lock *lock = &block->b_call->a_args.lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 int error;
731
732 dprintk("lockd: grant blocked lock %p\n", block);
733
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500734 kref_get(&block->b_count);
735
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 /* Unlink block request from list */
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500737 nlmsvc_unlink_block(block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738
739 /* If b_granted is true this means we've been here before.
740 * Just retry the grant callback, possibly refreshing the RPC
741 * binding */
742 if (block->b_granted) {
743 nlm_rebind_host(block->b_host);
744 goto callback;
745 }
746
747 /* Try the lock operation again */
Trond Myklebust09c79382006-03-20 13:44:38 -0500748 lock->fl.fl_flags |= FL_SLEEP;
Marc Eshel1a8322b2006-11-28 16:27:06 -0500749 error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL);
Trond Myklebust09c79382006-03-20 13:44:38 -0500750 lock->fl.fl_flags &= ~FL_SLEEP;
751
Andy Adamson5de0e502006-03-20 13:44:25 -0500752 switch (error) {
753 case 0:
754 break;
Miklos Szeredibde74e42008-07-25 01:48:57 -0700755 case FILE_LOCK_DEFERRED:
Marc Eshel1a8322b2006-11-28 16:27:06 -0500756 dprintk("lockd: lock still blocked error %d\n", error);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 nlmsvc_insert_block(block, NLM_NEVER);
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500758 nlmsvc_release_block(block);
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500759 return;
Andy Adamson5de0e502006-03-20 13:44:25 -0500760 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 printk(KERN_WARNING "lockd: unexpected error %d in %s!\n",
Harvey Harrison8e24eea2008-04-30 00:55:09 -0700762 -error, __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 nlmsvc_insert_block(block, 10 * HZ);
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500764 nlmsvc_release_block(block);
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500765 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766 }
767
768callback:
769 /* Lock was granted by VFS. */
770 dprintk("lockd: GRANTing blocked lock.\n");
771 block->b_granted = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772
Jeff Layton97065012008-02-06 11:34:12 -0500773 /* keep block on the list, but don't reattempt until the RPC
774 * completes or the submission fails
775 */
776 nlmsvc_insert_block(block, NLM_NEVER);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777
Jeff Layton97065012008-02-06 11:34:12 -0500778 /* Call the client -- use a soft RPC task since nlmsvc_retry_blocked
779 * will queue up a new one if this one times out
780 */
781 error = nlm_async_call(block->b_call, NLMPROC_GRANTED_MSG,
782 &nlmsvc_grant_ops);
783
784 /* RPC submission failed, wait a bit and retry */
785 if (error < 0)
786 nlmsvc_insert_block(block, 10 * HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787}
788
789/*
790 * This is the callback from the RPC layer when the NLM_GRANTED_MSG
791 * RPC call has succeeded or timed out.
792 * Like all RPC callbacks, it is invoked by the rpciod process, so it
793 * better not sleep. Therefore, we put the blocked lock on the nlm_blocked
794 * chain once more in order to have it removed by lockd itself (which can
795 * then sleep on the file semaphore without disrupting e.g. the nfs client).
796 */
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100797static void nlmsvc_grant_callback(struct rpc_task *task, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798{
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100799 struct nlm_rqst *call = data;
Trond Myklebust92737232006-03-20 13:44:45 -0500800 struct nlm_block *block = call->a_block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 unsigned long timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802
803 dprintk("lockd: GRANT_MSG RPC callback\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804
Trond Myklebusta86dc492008-06-11 13:37:09 -0400805 lock_kernel();
Jeff Laytonc64e80d2008-02-06 11:34:13 -0500806 /* if the block is not on a list at this point then it has
807 * been invalidated. Don't try to requeue it.
808 *
809 * FIXME: it's possible that the block is removed from the list
810 * after this check but before the nlmsvc_insert_block. In that
811 * case it will be added back. Perhaps we need better locking
812 * for nlm_blocked?
813 */
814 if (list_empty(&block->b_list))
Trond Myklebusta86dc492008-06-11 13:37:09 -0400815 goto out;
Jeff Laytonc64e80d2008-02-06 11:34:13 -0500816
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817 /* Technically, we should down the file semaphore here. Since we
818 * move the block towards the head of the queue only, no harm
819 * can be done, though. */
820 if (task->tk_status < 0) {
821 /* RPC error: Re-insert for retransmission */
822 timeout = 10 * HZ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 } else {
824 /* Call was successful, now wait for client callback */
825 timeout = 60 * HZ;
826 }
827 nlmsvc_insert_block(block, timeout);
828 svc_wake_up(block->b_daemon);
Trond Myklebusta86dc492008-06-11 13:37:09 -0400829out:
830 unlock_kernel();
Trond Myklebust5e1abf82006-03-20 13:44:39 -0500831}
832
Adrian Bunkec535ce2006-04-18 13:21:50 -0400833static void nlmsvc_grant_release(void *data)
Trond Myklebust5e1abf82006-03-20 13:44:39 -0500834{
Trond Myklebust6041b792006-03-20 13:44:45 -0500835 struct nlm_rqst *call = data;
836
Trond Myklebusta86dc492008-06-11 13:37:09 -0400837 lock_kernel();
Trond Myklebust6041b792006-03-20 13:44:45 -0500838 nlmsvc_release_block(call->a_block);
Trond Myklebusta86dc492008-06-11 13:37:09 -0400839 unlock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700840}
841
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100842static const struct rpc_call_ops nlmsvc_grant_ops = {
843 .rpc_call_done = nlmsvc_grant_callback,
Trond Myklebust5e1abf82006-03-20 13:44:39 -0500844 .rpc_release = nlmsvc_grant_release,
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100845};
846
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847/*
848 * We received a GRANT_RES callback. Try to find the corresponding
849 * block.
850 */
851void
Al Viroe8c5c042006-12-13 00:35:03 -0800852nlmsvc_grant_reply(struct nlm_cookie *cookie, __be32 status)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853{
854 struct nlm_block *block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855
Olaf Kirch39be4502006-10-04 02:16:03 -0700856 dprintk("grant_reply: looking for cookie %x, s=%d \n",
857 *(unsigned int *)(cookie->data), status);
858 if (!(block = nlmsvc_find_block(cookie)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860
J. Bruce Fieldsf2321422006-01-03 09:55:42 +0100861 if (block) {
Al Viroe8c5c042006-12-13 00:35:03 -0800862 if (status == nlm_lck_denied_grace_period) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863 /* Try again in a couple of seconds */
864 nlmsvc_insert_block(block, 10 * HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 } else {
866 /* Lock is now held by client, or has been rejected.
867 * In both cases, the block should be removed. */
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500868 nlmsvc_unlink_block(block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869 }
870 }
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500871 nlmsvc_release_block(block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872}
873
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500874/* Helper function to handle retry of a deferred block.
875 * If it is a blocking lock, call grant_blocked.
876 * For a non-blocking lock or test lock, revisit the request.
877 */
878static void
879retry_deferred_block(struct nlm_block *block)
880{
881 if (!(block->b_flags & B_GOT_CALLBACK))
882 block->b_flags |= B_TIMED_OUT;
883 nlmsvc_insert_block(block, NLM_TIMEOUT);
884 dprintk("revisit block %p flags %d\n", block, block->b_flags);
885 if (block->b_deferred_req) {
886 block->b_deferred_req->revisit(block->b_deferred_req, 0);
887 block->b_deferred_req = NULL;
888 }
889}
890
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891/*
892 * Retry all blocked locks that have been notified. This is where lockd
893 * picks up locks that can be granted, or grant notifications that must
894 * be retransmitted.
895 */
896unsigned long
897nlmsvc_retry_blocked(void)
898{
Olaf Kirch68a2d762006-10-04 02:15:57 -0700899 unsigned long timeout = MAX_SCHEDULE_TIMEOUT;
900 struct nlm_block *block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901
Jeff Laytond751a7c2008-02-07 16:34:55 -0500902 while (!list_empty(&nlm_blocked) && !kthread_should_stop()) {
Olaf Kirch68a2d762006-10-04 02:15:57 -0700903 block = list_entry(nlm_blocked.next, struct nlm_block, b_list);
904
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905 if (block->b_when == NLM_NEVER)
906 break;
J. Bruce Fields6d7bbbb2008-07-15 14:38:32 -0400907 if (time_after(block->b_when, jiffies)) {
Olaf Kirch68a2d762006-10-04 02:15:57 -0700908 timeout = block->b_when - jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909 break;
Olaf Kirch68a2d762006-10-04 02:15:57 -0700910 }
911
J. Bruce Fieldsf3d43c72006-08-03 15:07:47 -0400912 dprintk("nlmsvc_retry_blocked(%p, when=%ld)\n",
913 block, block->b_when);
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500914 if (block->b_flags & B_QUEUED) {
915 dprintk("nlmsvc_retry_blocked delete block (%p, granted=%d, flags=%d)\n",
916 block, block->b_granted, block->b_flags);
917 retry_deferred_block(block);
918 } else
919 nlmsvc_grant_blocked(block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 }
921
Olaf Kirch68a2d762006-10-04 02:15:57 -0700922 return timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923}