blob: 9e4d6aab611b829a22640e7bcdbcbecfc6ee5c45 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/lockd/svcsubs.c
3 *
4 * Various support routines for the NLM server.
5 *
6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
7 */
8
Linus Torvalds1da177e2005-04-16 15:20:36 -07009#include <linux/types.h>
10#include <linux/string.h>
11#include <linux/time.h>
12#include <linux/in.h>
Ingo Molnar353ab6e2006-03-26 01:37:12 -080013#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/sunrpc/svc.h>
15#include <linux/sunrpc/clnt.h>
16#include <linux/nfsd/nfsfh.h>
17#include <linux/nfsd/export.h>
18#include <linux/lockd/lockd.h>
19#include <linux/lockd/share.h>
Wendy Cheng4373ea82008-01-17 11:10:12 -050020#include <linux/module.h>
21#include <linux/mount.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
23#define NLMDBG_FACILITY NLMDBG_SVCSUBS
24
25
26/*
27 * Global file hash table
28 */
Olaf Kirch07ba8062006-10-04 02:15:58 -070029#define FILE_HASH_BITS 7
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#define FILE_NRHASH (1<<FILE_HASH_BITS)
Olaf Kirch07ba8062006-10-04 02:15:58 -070031static struct hlist_head nlm_files[FILE_NRHASH];
Ingo Molnar353ab6e2006-03-26 01:37:12 -080032static DEFINE_MUTEX(nlm_file_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
Chuck Lever0bbacc42005-11-01 16:53:32 -050034#ifdef NFSD_DEBUG
35static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f)
36{
37 u32 *fhp = (u32*)f->data;
38
39 /* print the first 32 bytes of the fh */
40 dprintk("lockd: %s (%08x %08x %08x %08x %08x %08x %08x %08x)\n",
41 msg, fhp[0], fhp[1], fhp[2], fhp[3],
42 fhp[4], fhp[5], fhp[6], fhp[7]);
43}
44
45static inline void nlm_debug_print_file(char *msg, struct nlm_file *file)
46{
Josef Sipek225a7192006-12-08 02:37:18 -080047 struct inode *inode = file->f_file->f_path.dentry->d_inode;
Chuck Lever0bbacc42005-11-01 16:53:32 -050048
49 dprintk("lockd: %s %s/%ld\n",
50 msg, inode->i_sb->s_id, inode->i_ino);
51}
52#else
53static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f)
54{
55 return;
56}
57
58static inline void nlm_debug_print_file(char *msg, struct nlm_file *file)
59{
60 return;
61}
62#endif
63
Linus Torvalds1da177e2005-04-16 15:20:36 -070064static inline unsigned int file_hash(struct nfs_fh *f)
65{
66 unsigned int tmp=0;
67 int i;
68 for (i=0; i<NFS2_FHSIZE;i++)
69 tmp += f->data[i];
70 return tmp & (FILE_NRHASH - 1);
71}
72
73/*
74 * Lookup file info. If it doesn't exist, create a file info struct
75 * and open a (VFS) file for the given inode.
76 *
77 * FIXME:
78 * Note that we open the file O_RDONLY even when creating write locks.
79 * This is not quite right, but for now, we assume the client performs
80 * the proper R/W checking.
81 */
Al Viro52921e02006-10-19 23:28:46 -070082__be32
Linus Torvalds1da177e2005-04-16 15:20:36 -070083nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
84 struct nfs_fh *f)
85{
Olaf Kirch07ba8062006-10-04 02:15:58 -070086 struct hlist_node *pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 struct nlm_file *file;
88 unsigned int hash;
Al Viro52921e02006-10-19 23:28:46 -070089 __be32 nfserr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
J. Bruce Fields50431d92007-08-31 17:09:33 -040091 nlm_debug_print_fh("nlm_lookup_file", f);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
93 hash = file_hash(f);
94
95 /* Lock file table */
Ingo Molnar353ab6e2006-03-26 01:37:12 -080096 mutex_lock(&nlm_file_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
Olaf Kirch07ba8062006-10-04 02:15:58 -070098 hlist_for_each_entry(file, pos, &nlm_files[hash], f_list)
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 if (!nfs_compare_fh(&file->f_handle, f))
100 goto found;
101
Chuck Lever0bbacc42005-11-01 16:53:32 -0500102 nlm_debug_print_fh("creating file for", f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
104 nfserr = nlm_lck_denied_nolocks;
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -0700105 file = kzalloc(sizeof(*file), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 if (!file)
107 goto out_unlock;
108
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 memcpy(&file->f_handle, f, sizeof(struct nfs_fh));
Neil Brown89e63ef2006-10-04 02:16:06 -0700110 mutex_init(&file->f_mutex);
Olaf Kirch07ba8062006-10-04 02:15:58 -0700111 INIT_HLIST_NODE(&file->f_list);
Olaf Kirch68a2d76c2006-10-04 02:15:57 -0700112 INIT_LIST_HEAD(&file->f_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113
114 /* Open the file. Note that this must not sleep for too long, else
115 * we would lock up lockd:-) So no NFS re-exports, folks.
116 *
117 * We have to make sure we have the right credential to open
118 * the file.
119 */
120 if ((nfserr = nlmsvc_ops->fopen(rqstp, f, &file->f_file)) != 0) {
Olaf Kirchf0737a32006-10-04 02:15:54 -0700121 dprintk("lockd: open failed (error %d)\n", nfserr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 goto out_free;
123 }
124
Olaf Kirch07ba8062006-10-04 02:15:58 -0700125 hlist_add_head(&file->f_list, &nlm_files[hash]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126
127found:
128 dprintk("lockd: found file %p (count %d)\n", file, file->f_count);
129 *result = file;
130 file->f_count++;
131 nfserr = 0;
132
133out_unlock:
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800134 mutex_unlock(&nlm_file_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 return nfserr;
136
137out_free:
138 kfree(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 goto out_unlock;
140}
141
142/*
143 * Delete a file after having released all locks, blocks and shares
144 */
145static inline void
146nlm_delete_file(struct nlm_file *file)
147{
Chuck Lever0bbacc42005-11-01 16:53:32 -0500148 nlm_debug_print_file("closing file", file);
Olaf Kirch07ba8062006-10-04 02:15:58 -0700149 if (!hlist_unhashed(&file->f_list)) {
150 hlist_del(&file->f_list);
151 nlmsvc_ops->fclose(file->f_file);
152 kfree(file);
153 } else {
154 printk(KERN_WARNING "lockd: attempt to release unknown file!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156}
157
158/*
159 * Loop over all locks on the given file and perform the specified
160 * action.
161 */
162static int
Olaf Kirchf2af7932006-10-04 02:15:59 -0700163nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file,
164 nlm_host_match_fn_t match)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165{
166 struct inode *inode = nlmsvc_file_inode(file);
167 struct file_lock *fl;
168 struct nlm_host *lockhost;
169
170again:
171 file->f_locks = 0;
172 for (fl = inode->i_flock; fl; fl = fl->fl_next) {
J. Bruce Fields7117bf32006-03-20 13:44:26 -0500173 if (fl->fl_lmops != &nlmsvc_lock_operations)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 continue;
175
176 /* update current lock count */
177 file->f_locks++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178
Olaf Kirchf2af7932006-10-04 02:15:59 -0700179 lockhost = (struct nlm_host *) fl->fl_owner;
180 if (match(lockhost, host)) {
181 struct file_lock lock = *fl;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
183 lock.fl_type = F_UNLCK;
184 lock.fl_start = 0;
185 lock.fl_end = OFFSET_MAX;
Marc Eshel1a8322b2006-11-28 16:27:06 -0500186 if (vfs_lock_file(file->f_file, F_SETLK, &lock, NULL) < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 printk("lockd: unlock failure in %s:%d\n",
188 __FILE__, __LINE__);
189 return 1;
190 }
191 goto again;
192 }
193 }
194
195 return 0;
196}
197
Wendy Cheng17efa372008-01-17 11:10:12 -0500198static int
199nlmsvc_always_match(void *dummy1, struct nlm_host *dummy2)
200{
201 return 1;
202}
203
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204/*
Olaf Kirchf2af7932006-10-04 02:15:59 -0700205 * Inspect a single file
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 */
207static inline int
Olaf Kirchf2af7932006-10-04 02:15:59 -0700208nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, nlm_host_match_fn_t match)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209{
Olaf Kirchf2af7932006-10-04 02:15:59 -0700210 nlmsvc_traverse_blocks(host, file, match);
211 nlmsvc_traverse_shares(host, file, match);
212 return nlm_traverse_locks(host, file, match);
213}
214
215/*
216 * Quick check whether there are still any locks, blocks or
217 * shares on a given file.
218 */
219static inline int
220nlm_file_inuse(struct nlm_file *file)
221{
222 struct inode *inode = nlmsvc_file_inode(file);
223 struct file_lock *fl;
224
225 if (file->f_count || !list_empty(&file->f_blocks) || file->f_shares)
226 return 1;
227
228 for (fl = inode->i_flock; fl; fl = fl->fl_next) {
229 if (fl->fl_lmops == &nlmsvc_lock_operations)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 }
Olaf Kirchf2af7932006-10-04 02:15:59 -0700232 file->f_locks = 0;
233 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234}
235
236/*
237 * Loop over all files in the file table.
238 */
239static int
Wendy Cheng17efa372008-01-17 11:10:12 -0500240nlm_traverse_files(void *data, nlm_host_match_fn_t match,
241 int (*is_failover_file)(void *data, struct nlm_file *file))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242{
Olaf Kirch07ba8062006-10-04 02:15:58 -0700243 struct hlist_node *pos, *next;
244 struct nlm_file *file;
Trond Myklebust01df9c52006-08-10 11:58:57 -0400245 int i, ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800247 mutex_lock(&nlm_file_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 for (i = 0; i < FILE_NRHASH; i++) {
Olaf Kirch07ba8062006-10-04 02:15:58 -0700249 hlist_for_each_entry_safe(file, pos, next, &nlm_files[i], f_list) {
Wendy Cheng17efa372008-01-17 11:10:12 -0500250 if (is_failover_file && !is_failover_file(data, file))
251 continue;
Trond Myklebust01df9c52006-08-10 11:58:57 -0400252 file->f_count++;
253 mutex_unlock(&nlm_file_mutex);
254
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 /* Traverse locks, blocks and shares of this file
256 * and update file->f_locks count */
Wendy Cheng4373ea82008-01-17 11:10:12 -0500257 if (nlm_inspect_file(data, file, match))
Trond Myklebust01df9c52006-08-10 11:58:57 -0400258 ret = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259
Trond Myklebust01df9c52006-08-10 11:58:57 -0400260 mutex_lock(&nlm_file_mutex);
261 file->f_count--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 /* No more references to this file. Let go of it. */
Olaf Kirch68a2d76c2006-10-04 02:15:57 -0700263 if (list_empty(&file->f_blocks) && !file->f_locks
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 && !file->f_shares && !file->f_count) {
Olaf Kirch07ba8062006-10-04 02:15:58 -0700265 hlist_del(&file->f_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 nlmsvc_ops->fclose(file->f_file);
267 kfree(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 }
269 }
270 }
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800271 mutex_unlock(&nlm_file_mutex);
Trond Myklebust01df9c52006-08-10 11:58:57 -0400272 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273}
274
275/*
276 * Release file. If there are no more remote locks on this file,
277 * close it and free the handle.
278 *
279 * Note that we can't do proper reference counting without major
280 * contortions because the code in fs/locks.c creates, deletes and
281 * splits locks without notification. Our only way is to walk the
282 * entire lock list each time we remove a lock.
283 */
284void
285nlm_release_file(struct nlm_file *file)
286{
287 dprintk("lockd: nlm_release_file(%p, ct = %d)\n",
288 file, file->f_count);
289
290 /* Lock file table */
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800291 mutex_lock(&nlm_file_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292
293 /* If there are no more locks etc, delete the file */
Olaf Kirchf2af7932006-10-04 02:15:59 -0700294 if (--file->f_count == 0 && !nlm_file_inuse(file))
295 nlm_delete_file(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800297 mutex_unlock(&nlm_file_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298}
299
300/*
Olaf Kirchf2af7932006-10-04 02:15:59 -0700301 * Helpers function for resource traversal
302 *
303 * nlmsvc_mark_host:
304 * used by the garbage collector; simply sets h_inuse.
305 * Always returns 0.
306 *
307 * nlmsvc_same_host:
308 * returns 1 iff the two hosts match. Used to release
309 * all resources bound to a specific host.
310 *
311 * nlmsvc_is_client:
312 * returns 1 iff the host is a client.
313 * Used by nlmsvc_invalidate_all
314 */
315static int
Wendy Cheng4373ea82008-01-17 11:10:12 -0500316nlmsvc_mark_host(void *data, struct nlm_host *dummy)
Olaf Kirchf2af7932006-10-04 02:15:59 -0700317{
Wendy Cheng4373ea82008-01-17 11:10:12 -0500318 struct nlm_host *host = data;
319
Olaf Kirchf2af7932006-10-04 02:15:59 -0700320 host->h_inuse = 1;
321 return 0;
322}
323
324static int
Wendy Cheng4373ea82008-01-17 11:10:12 -0500325nlmsvc_same_host(void *data, struct nlm_host *other)
Olaf Kirchf2af7932006-10-04 02:15:59 -0700326{
Wendy Cheng4373ea82008-01-17 11:10:12 -0500327 struct nlm_host *host = data;
328
Olaf Kirchf2af7932006-10-04 02:15:59 -0700329 return host == other;
330}
331
332static int
Wendy Cheng4373ea82008-01-17 11:10:12 -0500333nlmsvc_is_client(void *data, struct nlm_host *dummy)
Olaf Kirchf2af7932006-10-04 02:15:59 -0700334{
Wendy Cheng4373ea82008-01-17 11:10:12 -0500335 struct nlm_host *host = data;
336
NeilBrown4481d102006-10-17 00:10:17 -0700337 if (host->h_server) {
338 /* we are destroying locks even though the client
339 * hasn't asked us too, so don't unmonitor the
340 * client
341 */
342 if (host->h_nsmhandle)
343 host->h_nsmhandle->sm_sticky = 1;
344 return 1;
345 } else
346 return 0;
Olaf Kirchf2af7932006-10-04 02:15:59 -0700347}
348
349/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 * Mark all hosts that still hold resources
351 */
352void
353nlmsvc_mark_resources(void)
354{
355 dprintk("lockd: nlmsvc_mark_resources\n");
Wendy Cheng17efa372008-01-17 11:10:12 -0500356 nlm_traverse_files(NULL, nlmsvc_mark_host, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357}
358
359/*
360 * Release all resources held by the given client
361 */
362void
363nlmsvc_free_host_resources(struct nlm_host *host)
364{
365 dprintk("lockd: nlmsvc_free_host_resources\n");
366
Wendy Cheng17efa372008-01-17 11:10:12 -0500367 if (nlm_traverse_files(host, nlmsvc_same_host, NULL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 printk(KERN_WARNING
Olaf Kirchf0737a32006-10-04 02:15:54 -0700369 "lockd: couldn't remove all locks held by %s\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 host->h_name);
Olaf Kirchf0737a32006-10-04 02:15:54 -0700371 BUG();
372 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373}
374
Chuck Lever367c8c72008-06-30 18:58:14 -0400375/**
376 * nlmsvc_invalidate_all - remove all locks held for clients
377 *
378 * Release all locks held by NFS clients.
379 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 */
381void
382nlmsvc_invalidate_all(void)
383{
Chuck Lever367c8c72008-06-30 18:58:14 -0400384 /*
Olaf Kirchf2af7932006-10-04 02:15:59 -0700385 * Previously, the code would call
386 * nlmsvc_free_host_resources for each client in
387 * turn, which is about as inefficient as it gets.
388 * Now we just do it once in nlm_traverse_files.
389 */
Wendy Cheng17efa372008-01-17 11:10:12 -0500390 nlm_traverse_files(NULL, nlmsvc_is_client, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391}
Wendy Cheng4373ea82008-01-17 11:10:12 -0500392
393static int
Wendy Cheng17efa372008-01-17 11:10:12 -0500394nlmsvc_match_sb(void *datap, struct nlm_file *file)
395{
396 struct super_block *sb = datap;
397
398 return sb == file->f_file->f_path.mnt->mnt_sb;
399}
400
Chuck Lever367c8c72008-06-30 18:58:14 -0400401/**
402 * nlmsvc_unlock_all_by_sb - release locks held on this file system
403 * @sb: super block
404 *
405 * Release all locks held by clients accessing this file system.
406 */
Wendy Cheng17efa372008-01-17 11:10:12 -0500407int
408nlmsvc_unlock_all_by_sb(struct super_block *sb)
409{
410 int ret;
411
412 ret = nlm_traverse_files(sb, nlmsvc_always_match, nlmsvc_match_sb);
413 return ret ? -EIO : 0;
414}
415EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_sb);
416
417static int
Wendy Cheng4373ea82008-01-17 11:10:12 -0500418nlmsvc_match_ip(void *datap, struct nlm_host *host)
419{
Chuck Lever781b61a2008-09-03 14:36:01 -0400420 return nlm_cmp_addr(nlm_srcaddr(host), datap);
Wendy Cheng4373ea82008-01-17 11:10:12 -0500421}
422
Chuck Lever367c8c72008-06-30 18:58:14 -0400423/**
424 * nlmsvc_unlock_all_by_ip - release local locks by IP address
425 * @server_addr: server's IP address as seen by clients
426 *
427 * Release all locks held by clients accessing this host
428 * via the passed in IP address.
429 */
Wendy Cheng4373ea82008-01-17 11:10:12 -0500430int
Chuck Lever367c8c72008-06-30 18:58:14 -0400431nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr)
Wendy Cheng4373ea82008-01-17 11:10:12 -0500432{
433 int ret;
Wendy Cheng4373ea82008-01-17 11:10:12 -0500434
Chuck Lever367c8c72008-06-30 18:58:14 -0400435 ret = nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL);
436 return ret ? -EIO : 0;
Wendy Cheng4373ea82008-01-17 11:10:12 -0500437}
438EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_ip);