blob: 6063a8e4b9f3223104843bce393882181b890539 [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);
Trond Myklebust5e1abf82006-03-20 13:44:39 -0500329}
330
331/*
Marc Eshel2b36f412006-11-28 16:26:47 -0500332 * Deferred lock request handling for non-blocking lock
333 */
Al Viroca5c8cd2007-07-26 17:33:49 +0100334static __be32
Marc Eshel2b36f412006-11-28 16:26:47 -0500335nlmsvc_defer_lock_rqst(struct svc_rqst *rqstp, struct nlm_block *block)
336{
Al Viroca5c8cd2007-07-26 17:33:49 +0100337 __be32 status = nlm_lck_denied_nolocks;
Marc Eshel2b36f412006-11-28 16:26:47 -0500338
339 block->b_flags |= B_QUEUED;
340
341 nlmsvc_insert_block(block, NLM_TIMEOUT);
342
343 block->b_cache_req = &rqstp->rq_chandle;
344 if (rqstp->rq_chandle.defer) {
345 block->b_deferred_req =
346 rqstp->rq_chandle.defer(block->b_cache_req);
347 if (block->b_deferred_req != NULL)
348 status = nlm_drop_reply;
349 }
350 dprintk("lockd: nlmsvc_defer_lock_rqst block %p flags %d status %d\n",
Al Viroca5c8cd2007-07-26 17:33:49 +0100351 block, block->b_flags, ntohl(status));
Marc Eshel2b36f412006-11-28 16:26:47 -0500352
353 return status;
354}
355
356/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 * Attempt to establish a lock, and if it can't be granted, block it
358 * if required.
359 */
Al Viro52921e02006-10-19 23:28:46 -0700360__be32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file,
Jeff Layton6cde4de2008-07-15 14:26:17 -0400362 struct nlm_host *host, struct nlm_lock *lock, int wait,
J. Bruce Fieldsb2b50282008-02-06 13:59:23 -0500363 struct nlm_cookie *cookie, int reclaim)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364{
Marc Eshelf8120482006-12-05 23:48:10 -0500365 struct nlm_block *block = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 int error;
Al Viro52921e02006-10-19 23:28:46 -0700367 __be32 ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368
369 dprintk("lockd: nlmsvc_lock(%s/%ld, ty=%d, pi=%d, %Ld-%Ld, bl=%d)\n",
Josef Sipek225a7192006-12-08 02:37:18 -0800370 file->f_file->f_path.dentry->d_inode->i_sb->s_id,
371 file->f_file->f_path.dentry->d_inode->i_ino,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 lock->fl.fl_type, lock->fl.fl_pid,
373 (long long)lock->fl.fl_start,
374 (long long)lock->fl.fl_end,
375 wait);
376
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 /* Lock file against concurrent access */
Neil Brown89e63ef2006-10-04 02:16:06 -0700378 mutex_lock(&file->f_mutex);
Marc Eshelf8120482006-12-05 23:48:10 -0500379 /* Get existing block (in case client is busy-waiting)
380 * or create new block
381 */
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500382 block = nlmsvc_lookup_block(file, lock);
Trond Myklebust09c79382006-03-20 13:44:38 -0500383 if (block == NULL) {
J. Bruce Fields560de0e2008-07-15 15:05:45 -0400384 block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
Marc Eshelf8120482006-12-05 23:48:10 -0500385 ret = nlm_lck_denied_nolocks;
386 if (block == NULL)
387 goto out;
Trond Myklebust92737232006-03-20 13:44:45 -0500388 lock = &block->b_call->a_args.lock;
Marc Eshelf8120482006-12-05 23:48:10 -0500389 } else
390 lock->fl.fl_flags &= ~FL_SLEEP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391
Marc Eshel1a8322b2006-11-28 16:27:06 -0500392 if (block->b_flags & B_QUEUED) {
393 dprintk("lockd: nlmsvc_lock deferred block %p flags %d\n",
394 block, block->b_flags);
395 if (block->b_granted) {
396 nlmsvc_unlink_block(block);
397 ret = nlm_granted;
398 goto out;
399 }
400 if (block->b_flags & B_TIMED_OUT) {
401 nlmsvc_unlink_block(block);
402 ret = nlm_lck_denied;
403 goto out;
404 }
405 ret = nlm_drop_reply;
406 goto out;
407 }
408
J. Bruce Fieldsb2b50282008-02-06 13:59:23 -0500409 if (locks_in_grace() && !reclaim) {
410 ret = nlm_lck_denied_grace_period;
411 goto out;
412 }
J. Bruce Fieldsd22b1cf2008-02-06 15:05:12 -0500413 if (reclaim && !locks_in_grace()) {
414 ret = nlm_lck_denied_grace_period;
415 goto out;
416 }
J. Bruce Fieldsb2b50282008-02-06 13:59:23 -0500417
Marc Eshel1a8322b2006-11-28 16:27:06 -0500418 if (!wait)
419 lock->fl.fl_flags &= ~FL_SLEEP;
420 error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL);
Trond Myklebust09c79382006-03-20 13:44:38 -0500421 lock->fl.fl_flags &= ~FL_SLEEP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422
Marc Eshel1a8322b2006-11-28 16:27:06 -0500423 dprintk("lockd: vfs_lock_file returned %d\n", error);
J. Bruce Fields6d7bbbb2008-07-15 14:38:32 -0400424 switch (error) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 case 0:
Andy Adamson15dadef2006-03-20 13:44:24 -0500426 ret = nlm_granted;
427 goto out;
Trond Myklebust09c79382006-03-20 13:44:38 -0500428 case -EAGAIN:
Marc Eshel1a8322b2006-11-28 16:27:06 -0500429 ret = nlm_lck_denied;
Miklos Szeredibde74e42008-07-25 01:48:57 -0700430 goto out;
431 case FILE_LOCK_DEFERRED:
Marc Eshel1a8322b2006-11-28 16:27:06 -0500432 if (wait)
433 break;
434 /* Filesystem lock operation is in progress
435 Add it to the queue waiting for callback */
436 ret = nlmsvc_defer_lock_rqst(rqstp, block);
437 goto out;
Trond Myklebust09c79382006-03-20 13:44:38 -0500438 case -EDEADLK:
Andy Adamson15dadef2006-03-20 13:44:24 -0500439 ret = nlm_deadlock;
440 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 default: /* includes ENOLCK */
Andy Adamson15dadef2006-03-20 13:44:24 -0500442 ret = nlm_lck_denied_nolocks;
443 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 }
445
Trond Myklebust09c79382006-03-20 13:44:38 -0500446 ret = nlm_lck_blocked;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447
448 /* Append to list of blocked */
Marc Eshelf8120482006-12-05 23:48:10 -0500449 nlmsvc_insert_block(block, NLM_NEVER);
Andy Adamson15dadef2006-03-20 13:44:24 -0500450out:
Neil Brown89e63ef2006-10-04 02:16:06 -0700451 mutex_unlock(&file->f_mutex);
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500452 nlmsvc_release_block(block);
Andy Adamson15dadef2006-03-20 13:44:24 -0500453 dprintk("lockd: nlmsvc_lock returned %u\n", ret);
454 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455}
456
457/*
458 * Test for presence of a conflicting lock.
459 */
Al Viro52921e02006-10-19 23:28:46 -0700460__be32
Marc Eshel85f3f1b32006-11-28 16:27:06 -0500461nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
Jeff Layton8f920d52008-07-15 14:06:48 -0400462 struct nlm_host *host, struct nlm_lock *lock,
463 struct nlm_lock *conflock, struct nlm_cookie *cookie)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464{
Marc Eshel5ea0d752006-11-28 16:27:06 -0500465 struct nlm_block *block = NULL;
466 int error;
467 __be32 ret;
468
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 dprintk("lockd: nlmsvc_testlock(%s/%ld, ty=%d, %Ld-%Ld)\n",
Josef Sipek225a7192006-12-08 02:37:18 -0800470 file->f_file->f_path.dentry->d_inode->i_sb->s_id,
471 file->f_file->f_path.dentry->d_inode->i_ino,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 lock->fl.fl_type,
473 (long long)lock->fl.fl_start,
474 (long long)lock->fl.fl_end);
475
Marc Eshel5ea0d752006-11-28 16:27:06 -0500476 /* Get existing block (in case client is busy-waiting) */
477 block = nlmsvc_lookup_block(file, lock);
478
479 if (block == NULL) {
480 struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
481
482 if (conf == NULL)
483 return nlm_granted;
Trond Myklebust255129d2007-09-25 15:55:03 -0400484 block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
Marc Eshel5ea0d752006-11-28 16:27:06 -0500485 if (block == NULL) {
486 kfree(conf);
487 return nlm_granted;
488 }
489 block->b_fl = conf;
490 }
491 if (block->b_flags & B_QUEUED) {
492 dprintk("lockd: nlmsvc_testlock deferred block %p flags %d fl %p\n",
493 block, block->b_flags, block->b_fl);
494 if (block->b_flags & B_TIMED_OUT) {
495 nlmsvc_unlink_block(block);
Oleg Drokin29dbf542007-11-29 14:02:21 -0500496 ret = nlm_lck_denied;
497 goto out;
Marc Eshel5ea0d752006-11-28 16:27:06 -0500498 }
499 if (block->b_flags & B_GOT_CALLBACK) {
Oleg Drokin54ca95e2008-01-11 21:57:35 -0500500 nlmsvc_unlink_block(block);
Marc Eshel5ea0d752006-11-28 16:27:06 -0500501 if (block->b_fl != NULL
502 && block->b_fl->fl_type != F_UNLCK) {
503 lock->fl = *block->b_fl;
504 goto conf_lock;
Oleg Drokin29dbf542007-11-29 14:02:21 -0500505 } else {
Oleg Drokin29dbf542007-11-29 14:02:21 -0500506 ret = nlm_granted;
507 goto out;
Marc Eshel5ea0d752006-11-28 16:27:06 -0500508 }
509 }
Oleg Drokin29dbf542007-11-29 14:02:21 -0500510 ret = nlm_drop_reply;
511 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 }
513
J. Bruce Fieldsb2b50282008-02-06 13:59:23 -0500514 if (locks_in_grace()) {
515 ret = nlm_lck_denied_grace_period;
516 goto out;
517 }
Marc Eshel5ea0d752006-11-28 16:27:06 -0500518 error = vfs_test_lock(file->f_file, &lock->fl);
Miklos Szeredibde74e42008-07-25 01:48:57 -0700519 if (error == FILE_LOCK_DEFERRED) {
Oleg Drokin29dbf542007-11-29 14:02:21 -0500520 ret = nlmsvc_defer_lock_rqst(rqstp, block);
521 goto out;
522 }
Marc Eshel5ea0d752006-11-28 16:27:06 -0500523 if (error) {
524 ret = nlm_lck_denied_nolocks;
525 goto out;
526 }
527 if (lock->fl.fl_type == F_UNLCK) {
528 ret = nlm_granted;
529 goto out;
530 }
531
532conf_lock:
533 dprintk("lockd: conflicting lock(ty=%d, %Ld-%Ld)\n",
534 lock->fl.fl_type, (long long)lock->fl.fl_start,
535 (long long)lock->fl.fl_end);
536 conflock->caller = "somehost"; /* FIXME */
537 conflock->len = strlen(conflock->caller);
538 conflock->oh.len = 0; /* don't return OH info */
539 conflock->svid = lock->fl.fl_pid;
540 conflock->fl.fl_type = lock->fl.fl_type;
541 conflock->fl.fl_start = lock->fl.fl_start;
542 conflock->fl.fl_end = lock->fl.fl_end;
543 ret = nlm_lck_denied;
544out:
545 if (block)
546 nlmsvc_release_block(block);
547 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548}
549
550/*
551 * Remove a lock.
552 * This implies a CANCEL call: We send a GRANT_MSG, the client replies
553 * with a GRANT_RES call which gets lost, and calls UNLOCK immediately
554 * afterwards. In this case the block will still be there, and hence
555 * must be removed.
556 */
Al Viro52921e02006-10-19 23:28:46 -0700557__be32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558nlmsvc_unlock(struct nlm_file *file, struct nlm_lock *lock)
559{
560 int error;
561
562 dprintk("lockd: nlmsvc_unlock(%s/%ld, pi=%d, %Ld-%Ld)\n",
Josef Sipek225a7192006-12-08 02:37:18 -0800563 file->f_file->f_path.dentry->d_inode->i_sb->s_id,
564 file->f_file->f_path.dentry->d_inode->i_ino,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 lock->fl.fl_pid,
566 (long long)lock->fl.fl_start,
567 (long long)lock->fl.fl_end);
568
569 /* First, cancel any lock that might be there */
570 nlmsvc_cancel_blocked(file, lock);
571
572 lock->fl.fl_type = F_UNLCK;
Marc Eshel1a8322b2006-11-28 16:27:06 -0500573 error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574
575 return (error < 0)? nlm_lck_denied_nolocks : nlm_granted;
576}
577
578/*
579 * Cancel a previously blocked request.
580 *
581 * A cancel request always overrides any grant that may currently
582 * be in progress.
583 * The calling procedure must check whether the file can be closed.
584 */
Al Viro52921e02006-10-19 23:28:46 -0700585__be32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586nlmsvc_cancel_blocked(struct nlm_file *file, struct nlm_lock *lock)
587{
588 struct nlm_block *block;
J. Bruce Fields64a318e2006-01-03 09:55:46 +0100589 int status = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590
591 dprintk("lockd: nlmsvc_cancel(%s/%ld, pi=%d, %Ld-%Ld)\n",
Josef Sipek225a7192006-12-08 02:37:18 -0800592 file->f_file->f_path.dentry->d_inode->i_sb->s_id,
593 file->f_file->f_path.dentry->d_inode->i_ino,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 lock->fl.fl_pid,
595 (long long)lock->fl.fl_start,
596 (long long)lock->fl.fl_end);
597
J. Bruce Fieldsb2b50282008-02-06 13:59:23 -0500598 if (locks_in_grace())
599 return nlm_lck_denied_grace_period;
600
Neil Brown89e63ef2006-10-04 02:16:06 -0700601 mutex_lock(&file->f_mutex);
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500602 block = nlmsvc_lookup_block(file, lock);
Neil Brown89e63ef2006-10-04 02:16:06 -0700603 mutex_unlock(&file->f_mutex);
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500604 if (block != NULL) {
Marc Eshel1a8322b2006-11-28 16:27:06 -0500605 vfs_cancel_lock(block->b_file->f_file,
606 &block->b_call->a_args.lock.fl);
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500607 status = nlmsvc_unlink_block(block);
608 nlmsvc_release_block(block);
609 }
J. Bruce Fields64a318e2006-01-03 09:55:46 +0100610 return status ? nlm_lck_denied : nlm_granted;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611}
612
613/*
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500614 * This is a callback from the filesystem for VFS file lock requests.
615 * It will be used if fl_grant is defined and the filesystem can not
616 * respond to the request immediately.
617 * For GETLK request it will copy the reply to the nlm_block.
618 * For SETLK or SETLKW request it will get the local posix lock.
619 * In all cases it will move the block to the head of nlm_blocked q where
620 * nlmsvc_retry_blocked() can send back a reply for SETLKW or revisit the
621 * deferred rpc for GETLK and SETLK.
622 */
623static void
624nlmsvc_update_deferred_block(struct nlm_block *block, struct file_lock *conf,
625 int result)
626{
627 block->b_flags |= B_GOT_CALLBACK;
628 if (result == 0)
629 block->b_granted = 1;
630 else
631 block->b_flags |= B_TIMED_OUT;
632 if (conf) {
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500633 if (block->b_fl)
J. Bruce Fields1a747ee2008-04-24 10:08:22 -0400634 __locks_copy_lock(block->b_fl, conf);
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500635 }
636}
637
638static int nlmsvc_grant_deferred(struct file_lock *fl, struct file_lock *conf,
639 int result)
640{
641 struct nlm_block *block;
642 int rc = -ENOENT;
643
644 lock_kernel();
645 list_for_each_entry(block, &nlm_blocked, b_list) {
646 if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) {
647 dprintk("lockd: nlmsvc_notify_blocked block %p flags %d\n",
648 block, block->b_flags);
649 if (block->b_flags & B_QUEUED) {
650 if (block->b_flags & B_TIMED_OUT) {
651 rc = -ENOLCK;
652 break;
653 }
654 nlmsvc_update_deferred_block(block, conf, result);
655 } else if (result == 0)
656 block->b_granted = 1;
657
658 nlmsvc_insert_block(block, 0);
659 svc_wake_up(block->b_daemon);
660 rc = 0;
661 break;
662 }
663 }
664 unlock_kernel();
665 if (rc == -ENOENT)
666 printk(KERN_WARNING "lockd: grant for unknown block\n");
667 return rc;
668}
669
670/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 * Unblock a blocked lock request. This is a callback invoked from the
672 * VFS layer when a lock on which we blocked is removed.
673 *
674 * This function doesn't grant the blocked lock instantly, but rather moves
675 * the block to the head of nlm_blocked where it can be picked up by lockd.
676 */
677static void
678nlmsvc_notify_blocked(struct file_lock *fl)
679{
Olaf Kirch68a2d762006-10-04 02:15:57 -0700680 struct nlm_block *block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681
682 dprintk("lockd: VFS unblock notification for block %p\n", fl);
Olaf Kirch68a2d762006-10-04 02:15:57 -0700683 list_for_each_entry(block, &nlm_blocked, b_list) {
Trond Myklebust92737232006-03-20 13:44:45 -0500684 if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 nlmsvc_insert_block(block, 0);
686 svc_wake_up(block->b_daemon);
687 return;
688 }
689 }
690
691 printk(KERN_WARNING "lockd: notification for unknown block!\n");
692}
693
694static int nlmsvc_same_owner(struct file_lock *fl1, struct file_lock *fl2)
695{
696 return fl1->fl_owner == fl2->fl_owner && fl1->fl_pid == fl2->fl_pid;
697}
698
699struct lock_manager_operations nlmsvc_lock_operations = {
700 .fl_compare_owner = nlmsvc_same_owner,
701 .fl_notify = nlmsvc_notify_blocked,
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500702 .fl_grant = nlmsvc_grant_deferred,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703};
704
705/*
706 * Try to claim a lock that was previously blocked.
707 *
708 * Note that we use both the RPC_GRANTED_MSG call _and_ an async
709 * RPC thread when notifying the client. This seems like overkill...
710 * Here's why:
711 * - we don't want to use a synchronous RPC thread, otherwise
712 * we might find ourselves hanging on a dead portmapper.
713 * - Some lockd implementations (e.g. HP) don't react to
714 * RPC_GRANTED calls; they seem to insist on RPC_GRANTED_MSG calls.
715 */
716static void
717nlmsvc_grant_blocked(struct nlm_block *block)
718{
719 struct nlm_file *file = block->b_file;
Trond Myklebust92737232006-03-20 13:44:45 -0500720 struct nlm_lock *lock = &block->b_call->a_args.lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 int error;
722
723 dprintk("lockd: grant blocked lock %p\n", block);
724
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500725 kref_get(&block->b_count);
726
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 /* Unlink block request from list */
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500728 nlmsvc_unlink_block(block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729
730 /* If b_granted is true this means we've been here before.
731 * Just retry the grant callback, possibly refreshing the RPC
732 * binding */
733 if (block->b_granted) {
734 nlm_rebind_host(block->b_host);
735 goto callback;
736 }
737
738 /* Try the lock operation again */
Trond Myklebust09c79382006-03-20 13:44:38 -0500739 lock->fl.fl_flags |= FL_SLEEP;
Marc Eshel1a8322b2006-11-28 16:27:06 -0500740 error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL);
Trond Myklebust09c79382006-03-20 13:44:38 -0500741 lock->fl.fl_flags &= ~FL_SLEEP;
742
Andy Adamson5de0e502006-03-20 13:44:25 -0500743 switch (error) {
744 case 0:
745 break;
Miklos Szeredibde74e42008-07-25 01:48:57 -0700746 case FILE_LOCK_DEFERRED:
Marc Eshel1a8322b2006-11-28 16:27:06 -0500747 dprintk("lockd: lock still blocked error %d\n", error);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 nlmsvc_insert_block(block, NLM_NEVER);
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500749 nlmsvc_release_block(block);
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500750 return;
Andy Adamson5de0e502006-03-20 13:44:25 -0500751 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752 printk(KERN_WARNING "lockd: unexpected error %d in %s!\n",
Harvey Harrison8e24eea2008-04-30 00:55:09 -0700753 -error, __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 nlmsvc_insert_block(block, 10 * HZ);
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500755 nlmsvc_release_block(block);
Trond Myklebustd9f6eb72006-03-20 13:44:47 -0500756 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 }
758
759callback:
760 /* Lock was granted by VFS. */
761 dprintk("lockd: GRANTing blocked lock.\n");
762 block->b_granted = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763
Jeff Layton97065012008-02-06 11:34:12 -0500764 /* keep block on the list, but don't reattempt until the RPC
765 * completes or the submission fails
766 */
767 nlmsvc_insert_block(block, NLM_NEVER);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768
Jeff Layton97065012008-02-06 11:34:12 -0500769 /* Call the client -- use a soft RPC task since nlmsvc_retry_blocked
770 * will queue up a new one if this one times out
771 */
772 error = nlm_async_call(block->b_call, NLMPROC_GRANTED_MSG,
773 &nlmsvc_grant_ops);
774
775 /* RPC submission failed, wait a bit and retry */
776 if (error < 0)
777 nlmsvc_insert_block(block, 10 * HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778}
779
780/*
781 * This is the callback from the RPC layer when the NLM_GRANTED_MSG
782 * RPC call has succeeded or timed out.
783 * Like all RPC callbacks, it is invoked by the rpciod process, so it
784 * better not sleep. Therefore, we put the blocked lock on the nlm_blocked
785 * chain once more in order to have it removed by lockd itself (which can
786 * then sleep on the file semaphore without disrupting e.g. the nfs client).
787 */
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100788static void nlmsvc_grant_callback(struct rpc_task *task, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789{
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100790 struct nlm_rqst *call = data;
Trond Myklebust92737232006-03-20 13:44:45 -0500791 struct nlm_block *block = call->a_block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792 unsigned long timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793
794 dprintk("lockd: GRANT_MSG RPC callback\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795
Trond Myklebusta86dc492008-06-11 13:37:09 -0400796 lock_kernel();
Jeff Laytonc64e80d2008-02-06 11:34:13 -0500797 /* if the block is not on a list at this point then it has
798 * been invalidated. Don't try to requeue it.
799 *
800 * FIXME: it's possible that the block is removed from the list
801 * after this check but before the nlmsvc_insert_block. In that
802 * case it will be added back. Perhaps we need better locking
803 * for nlm_blocked?
804 */
805 if (list_empty(&block->b_list))
Trond Myklebusta86dc492008-06-11 13:37:09 -0400806 goto out;
Jeff Laytonc64e80d2008-02-06 11:34:13 -0500807
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808 /* Technically, we should down the file semaphore here. Since we
809 * move the block towards the head of the queue only, no harm
810 * can be done, though. */
811 if (task->tk_status < 0) {
812 /* RPC error: Re-insert for retransmission */
813 timeout = 10 * HZ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814 } else {
815 /* Call was successful, now wait for client callback */
816 timeout = 60 * HZ;
817 }
818 nlmsvc_insert_block(block, timeout);
819 svc_wake_up(block->b_daemon);
Trond Myklebusta86dc492008-06-11 13:37:09 -0400820out:
821 unlock_kernel();
Trond Myklebust5e1abf82006-03-20 13:44:39 -0500822}
823
Adrian Bunkec535ce2006-04-18 13:21:50 -0400824static void nlmsvc_grant_release(void *data)
Trond Myklebust5e1abf82006-03-20 13:44:39 -0500825{
Trond Myklebust6041b792006-03-20 13:44:45 -0500826 struct nlm_rqst *call = data;
827
Trond Myklebusta86dc492008-06-11 13:37:09 -0400828 lock_kernel();
Trond Myklebust6041b792006-03-20 13:44:45 -0500829 nlmsvc_release_block(call->a_block);
Trond Myklebusta86dc492008-06-11 13:37:09 -0400830 unlock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831}
832
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100833static const struct rpc_call_ops nlmsvc_grant_ops = {
834 .rpc_call_done = nlmsvc_grant_callback,
Trond Myklebust5e1abf82006-03-20 13:44:39 -0500835 .rpc_release = nlmsvc_grant_release,
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100836};
837
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838/*
839 * We received a GRANT_RES callback. Try to find the corresponding
840 * block.
841 */
842void
Al Viroe8c5c042006-12-13 00:35:03 -0800843nlmsvc_grant_reply(struct nlm_cookie *cookie, __be32 status)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844{
845 struct nlm_block *block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846
Olaf Kirch39be4502006-10-04 02:16:03 -0700847 dprintk("grant_reply: looking for cookie %x, s=%d \n",
848 *(unsigned int *)(cookie->data), status);
849 if (!(block = nlmsvc_find_block(cookie)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851
J. Bruce Fieldsf2321422006-01-03 09:55:42 +0100852 if (block) {
Al Viroe8c5c042006-12-13 00:35:03 -0800853 if (status == nlm_lck_denied_grace_period) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854 /* Try again in a couple of seconds */
855 nlmsvc_insert_block(block, 10 * HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856 } else {
857 /* Lock is now held by client, or has been rejected.
858 * In both cases, the block should be removed. */
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500859 nlmsvc_unlink_block(block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860 }
861 }
Trond Myklebust6849c0c2006-03-20 13:44:39 -0500862 nlmsvc_release_block(block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863}
864
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500865/* Helper function to handle retry of a deferred block.
866 * If it is a blocking lock, call grant_blocked.
867 * For a non-blocking lock or test lock, revisit the request.
868 */
869static void
870retry_deferred_block(struct nlm_block *block)
871{
872 if (!(block->b_flags & B_GOT_CALLBACK))
873 block->b_flags |= B_TIMED_OUT;
874 nlmsvc_insert_block(block, NLM_TIMEOUT);
875 dprintk("revisit block %p flags %d\n", block, block->b_flags);
876 if (block->b_deferred_req) {
877 block->b_deferred_req->revisit(block->b_deferred_req, 0);
878 block->b_deferred_req = NULL;
879 }
880}
881
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882/*
883 * Retry all blocked locks that have been notified. This is where lockd
884 * picks up locks that can be granted, or grant notifications that must
885 * be retransmitted.
886 */
887unsigned long
888nlmsvc_retry_blocked(void)
889{
Olaf Kirch68a2d762006-10-04 02:15:57 -0700890 unsigned long timeout = MAX_SCHEDULE_TIMEOUT;
891 struct nlm_block *block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892
Jeff Laytond751a7c2008-02-07 16:34:55 -0500893 while (!list_empty(&nlm_blocked) && !kthread_should_stop()) {
Olaf Kirch68a2d762006-10-04 02:15:57 -0700894 block = list_entry(nlm_blocked.next, struct nlm_block, b_list);
895
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 if (block->b_when == NLM_NEVER)
897 break;
J. Bruce Fields6d7bbbb2008-07-15 14:38:32 -0400898 if (time_after(block->b_when, jiffies)) {
Olaf Kirch68a2d762006-10-04 02:15:57 -0700899 timeout = block->b_when - jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900 break;
Olaf Kirch68a2d762006-10-04 02:15:57 -0700901 }
902
J. Bruce Fieldsf3d43c72006-08-03 15:07:47 -0400903 dprintk("nlmsvc_retry_blocked(%p, when=%ld)\n",
904 block, block->b_when);
Marc Eshel0e4ac9d2006-11-28 16:26:51 -0500905 if (block->b_flags & B_QUEUED) {
906 dprintk("nlmsvc_retry_blocked delete block (%p, granted=%d, flags=%d)\n",
907 block, block->b_granted, block->b_flags);
908 retry_deferred_block(block);
909 } else
910 nlmsvc_grant_blocked(block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 }
912
Olaf Kirch68a2d762006-10-04 02:15:57 -0700913 return timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914}