blob: d0ef94cfb3da4d218b66a0a4046d96ab30506f3b [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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090013#include <linux/slab.h>
Ingo Molnar353ab6e2006-03-26 01:37:12 -080014#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/sunrpc/svc.h>
16#include <linux/sunrpc/clnt.h>
17#include <linux/nfsd/nfsfh.h>
18#include <linux/nfsd/export.h>
19#include <linux/lockd/lockd.h>
20#include <linux/lockd/share.h>
Wendy Cheng4373ea82008-01-17 11:10:12 -050021#include <linux/module.h>
22#include <linux/mount.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023
24#define NLMDBG_FACILITY NLMDBG_SVCSUBS
25
26
27/*
28 * Global file hash table
29 */
Olaf Kirch07ba8062006-10-04 02:15:58 -070030#define FILE_HASH_BITS 7
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#define FILE_NRHASH (1<<FILE_HASH_BITS)
Olaf Kirch07ba8062006-10-04 02:15:58 -070032static struct hlist_head nlm_files[FILE_NRHASH];
Ingo Molnar353ab6e2006-03-26 01:37:12 -080033static DEFINE_MUTEX(nlm_file_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
Chuck Lever0bbacc42005-11-01 16:53:32 -050035#ifdef NFSD_DEBUG
36static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f)
37{
38 u32 *fhp = (u32*)f->data;
39
40 /* print the first 32 bytes of the fh */
41 dprintk("lockd: %s (%08x %08x %08x %08x %08x %08x %08x %08x)\n",
42 msg, fhp[0], fhp[1], fhp[2], fhp[3],
43 fhp[4], fhp[5], fhp[6], fhp[7]);
44}
45
46static inline void nlm_debug_print_file(char *msg, struct nlm_file *file)
47{
Josef Sipek225a7192006-12-08 02:37:18 -080048 struct inode *inode = file->f_file->f_path.dentry->d_inode;
Chuck Lever0bbacc42005-11-01 16:53:32 -050049
50 dprintk("lockd: %s %s/%ld\n",
51 msg, inode->i_sb->s_id, inode->i_ino);
52}
53#else
54static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f)
55{
56 return;
57}
58
59static inline void nlm_debug_print_file(char *msg, struct nlm_file *file)
60{
61 return;
62}
63#endif
64
Linus Torvalds1da177e2005-04-16 15:20:36 -070065static inline unsigned int file_hash(struct nfs_fh *f)
66{
67 unsigned int tmp=0;
68 int i;
69 for (i=0; i<NFS2_FHSIZE;i++)
70 tmp += f->data[i];
71 return tmp & (FILE_NRHASH - 1);
72}
73
74/*
75 * Lookup file info. If it doesn't exist, create a file info struct
76 * and open a (VFS) file for the given inode.
77 *
78 * FIXME:
79 * Note that we open the file O_RDONLY even when creating write locks.
80 * This is not quite right, but for now, we assume the client performs
81 * the proper R/W checking.
82 */
Al Viro52921e02006-10-19 23:28:46 -070083__be32
Linus Torvalds1da177e2005-04-16 15:20:36 -070084nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
85 struct nfs_fh *f)
86{
Olaf Kirch07ba8062006-10-04 02:15:58 -070087 struct hlist_node *pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 struct nlm_file *file;
89 unsigned int hash;
Al Viro52921e02006-10-19 23:28:46 -070090 __be32 nfserr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070091
J. Bruce Fields50431d92007-08-31 17:09:33 -040092 nlm_debug_print_fh("nlm_lookup_file", f);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093
94 hash = file_hash(f);
95
96 /* Lock file table */
Ingo Molnar353ab6e2006-03-26 01:37:12 -080097 mutex_lock(&nlm_file_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
Olaf Kirch07ba8062006-10-04 02:15:58 -070099 hlist_for_each_entry(file, pos, &nlm_files[hash], f_list)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 if (!nfs_compare_fh(&file->f_handle, f))
101 goto found;
102
Chuck Lever0bbacc42005-11-01 16:53:32 -0500103 nlm_debug_print_fh("creating file for", f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104
105 nfserr = nlm_lck_denied_nolocks;
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -0700106 file = kzalloc(sizeof(*file), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 if (!file)
108 goto out_unlock;
109
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 memcpy(&file->f_handle, f, sizeof(struct nfs_fh));
Neil Brown89e63ef2006-10-04 02:16:06 -0700111 mutex_init(&file->f_mutex);
Olaf Kirch07ba8062006-10-04 02:15:58 -0700112 INIT_HLIST_NODE(&file->f_list);
Olaf Kirch68a2d762006-10-04 02:15:57 -0700113 INIT_LIST_HEAD(&file->f_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
115 /* Open the file. Note that this must not sleep for too long, else
116 * we would lock up lockd:-) So no NFS re-exports, folks.
117 *
118 * We have to make sure we have the right credential to open
119 * the file.
120 */
121 if ((nfserr = nlmsvc_ops->fopen(rqstp, f, &file->f_file)) != 0) {
Olaf Kirchf0737a32006-10-04 02:15:54 -0700122 dprintk("lockd: open failed (error %d)\n", nfserr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 goto out_free;
124 }
125
Olaf Kirch07ba8062006-10-04 02:15:58 -0700126 hlist_add_head(&file->f_list, &nlm_files[hash]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127
128found:
129 dprintk("lockd: found file %p (count %d)\n", file, file->f_count);
130 *result = file;
131 file->f_count++;
132 nfserr = 0;
133
134out_unlock:
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800135 mutex_unlock(&nlm_file_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 return nfserr;
137
138out_free:
139 kfree(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 goto out_unlock;
141}
142
143/*
144 * Delete a file after having released all locks, blocks and shares
145 */
146static inline void
147nlm_delete_file(struct nlm_file *file)
148{
Chuck Lever0bbacc42005-11-01 16:53:32 -0500149 nlm_debug_print_file("closing file", file);
Olaf Kirch07ba8062006-10-04 02:15:58 -0700150 if (!hlist_unhashed(&file->f_list)) {
151 hlist_del(&file->f_list);
152 nlmsvc_ops->fclose(file->f_file);
153 kfree(file);
154 } else {
155 printk(KERN_WARNING "lockd: attempt to release unknown file!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157}
158
159/*
160 * Loop over all locks on the given file and perform the specified
161 * action.
162 */
163static int
Olaf Kirchf2af7932006-10-04 02:15:59 -0700164nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file,
165 nlm_host_match_fn_t match)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166{
167 struct inode *inode = nlmsvc_file_inode(file);
168 struct file_lock *fl;
169 struct nlm_host *lockhost;
170
171again:
172 file->f_locks = 0;
173 for (fl = inode->i_flock; fl; fl = fl->fl_next) {
J. Bruce Fields7117bf32006-03-20 13:44:26 -0500174 if (fl->fl_lmops != &nlmsvc_lock_operations)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 continue;
176
177 /* update current lock count */
178 file->f_locks++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179
Olaf Kirchf2af7932006-10-04 02:15:59 -0700180 lockhost = (struct nlm_host *) fl->fl_owner;
181 if (match(lockhost, host)) {
182 struct file_lock lock = *fl;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
184 lock.fl_type = F_UNLCK;
185 lock.fl_start = 0;
186 lock.fl_end = OFFSET_MAX;
Marc Eshel1a8322b2006-11-28 16:27:06 -0500187 if (vfs_lock_file(file->f_file, F_SETLK, &lock, NULL) < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 printk("lockd: unlock failure in %s:%d\n",
189 __FILE__, __LINE__);
190 return 1;
191 }
192 goto again;
193 }
194 }
195
196 return 0;
197}
198
Wendy Cheng17efa372008-01-17 11:10:12 -0500199static int
200nlmsvc_always_match(void *dummy1, struct nlm_host *dummy2)
201{
202 return 1;
203}
204
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205/*
Olaf Kirchf2af7932006-10-04 02:15:59 -0700206 * Inspect a single file
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 */
208static inline int
Olaf Kirchf2af7932006-10-04 02:15:59 -0700209nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, nlm_host_match_fn_t match)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210{
Olaf Kirchf2af7932006-10-04 02:15:59 -0700211 nlmsvc_traverse_blocks(host, file, match);
212 nlmsvc_traverse_shares(host, file, match);
213 return nlm_traverse_locks(host, file, match);
214}
215
216/*
217 * Quick check whether there are still any locks, blocks or
218 * shares on a given file.
219 */
220static inline int
221nlm_file_inuse(struct nlm_file *file)
222{
223 struct inode *inode = nlmsvc_file_inode(file);
224 struct file_lock *fl;
225
226 if (file->f_count || !list_empty(&file->f_blocks) || file->f_shares)
227 return 1;
228
229 for (fl = inode->i_flock; fl; fl = fl->fl_next) {
230 if (fl->fl_lmops == &nlmsvc_lock_operations)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 }
Olaf Kirchf2af7932006-10-04 02:15:59 -0700233 file->f_locks = 0;
234 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235}
236
237/*
238 * Loop over all files in the file table.
239 */
240static int
Wendy Cheng17efa372008-01-17 11:10:12 -0500241nlm_traverse_files(void *data, nlm_host_match_fn_t match,
242 int (*is_failover_file)(void *data, struct nlm_file *file))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243{
Olaf Kirch07ba8062006-10-04 02:15:58 -0700244 struct hlist_node *pos, *next;
245 struct nlm_file *file;
Trond Myklebust01df9c52006-08-10 11:58:57 -0400246 int i, ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800248 mutex_lock(&nlm_file_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 for (i = 0; i < FILE_NRHASH; i++) {
Olaf Kirch07ba8062006-10-04 02:15:58 -0700250 hlist_for_each_entry_safe(file, pos, next, &nlm_files[i], f_list) {
Wendy Cheng17efa372008-01-17 11:10:12 -0500251 if (is_failover_file && !is_failover_file(data, file))
252 continue;
Trond Myklebust01df9c52006-08-10 11:58:57 -0400253 file->f_count++;
254 mutex_unlock(&nlm_file_mutex);
255
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 /* Traverse locks, blocks and shares of this file
257 * and update file->f_locks count */
Wendy Cheng4373ea82008-01-17 11:10:12 -0500258 if (nlm_inspect_file(data, file, match))
Trond Myklebust01df9c52006-08-10 11:58:57 -0400259 ret = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260
Trond Myklebust01df9c52006-08-10 11:58:57 -0400261 mutex_lock(&nlm_file_mutex);
262 file->f_count--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 /* No more references to this file. Let go of it. */
Olaf Kirch68a2d762006-10-04 02:15:57 -0700264 if (list_empty(&file->f_blocks) && !file->f_locks
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 && !file->f_shares && !file->f_count) {
Olaf Kirch07ba8062006-10-04 02:15:58 -0700266 hlist_del(&file->f_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 nlmsvc_ops->fclose(file->f_file);
268 kfree(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 }
270 }
271 }
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800272 mutex_unlock(&nlm_file_mutex);
Trond Myklebust01df9c52006-08-10 11:58:57 -0400273 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274}
275
276/*
277 * Release file. If there are no more remote locks on this file,
278 * close it and free the handle.
279 *
280 * Note that we can't do proper reference counting without major
281 * contortions because the code in fs/locks.c creates, deletes and
282 * splits locks without notification. Our only way is to walk the
283 * entire lock list each time we remove a lock.
284 */
285void
286nlm_release_file(struct nlm_file *file)
287{
288 dprintk("lockd: nlm_release_file(%p, ct = %d)\n",
289 file, file->f_count);
290
291 /* Lock file table */
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800292 mutex_lock(&nlm_file_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293
294 /* If there are no more locks etc, delete the file */
Olaf Kirchf2af7932006-10-04 02:15:59 -0700295 if (--file->f_count == 0 && !nlm_file_inuse(file))
296 nlm_delete_file(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800298 mutex_unlock(&nlm_file_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299}
300
301/*
Olaf Kirchf2af7932006-10-04 02:15:59 -0700302 * Helpers function for resource traversal
303 *
304 * nlmsvc_mark_host:
305 * used by the garbage collector; simply sets h_inuse.
306 * Always returns 0.
307 *
308 * nlmsvc_same_host:
309 * returns 1 iff the two hosts match. Used to release
310 * all resources bound to a specific host.
311 *
312 * nlmsvc_is_client:
313 * returns 1 iff the host is a client.
314 * Used by nlmsvc_invalidate_all
315 */
316static int
Wendy Cheng4373ea82008-01-17 11:10:12 -0500317nlmsvc_mark_host(void *data, struct nlm_host *dummy)
Olaf Kirchf2af7932006-10-04 02:15:59 -0700318{
Wendy Cheng4373ea82008-01-17 11:10:12 -0500319 struct nlm_host *host = data;
320
Olaf Kirchf2af7932006-10-04 02:15:59 -0700321 host->h_inuse = 1;
322 return 0;
323}
324
325static int
Wendy Cheng4373ea82008-01-17 11:10:12 -0500326nlmsvc_same_host(void *data, struct nlm_host *other)
Olaf Kirchf2af7932006-10-04 02:15:59 -0700327{
Wendy Cheng4373ea82008-01-17 11:10:12 -0500328 struct nlm_host *host = data;
329
Olaf Kirchf2af7932006-10-04 02:15:59 -0700330 return host == other;
331}
332
333static int
Wendy Cheng4373ea82008-01-17 11:10:12 -0500334nlmsvc_is_client(void *data, struct nlm_host *dummy)
Olaf Kirchf2af7932006-10-04 02:15:59 -0700335{
Wendy Cheng4373ea82008-01-17 11:10:12 -0500336 struct nlm_host *host = data;
337
NeilBrown4481d102006-10-17 00:10:17 -0700338 if (host->h_server) {
339 /* we are destroying locks even though the client
340 * hasn't asked us too, so don't unmonitor the
341 * client
342 */
343 if (host->h_nsmhandle)
344 host->h_nsmhandle->sm_sticky = 1;
345 return 1;
346 } else
347 return 0;
Olaf Kirchf2af7932006-10-04 02:15:59 -0700348}
349
350/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 * Mark all hosts that still hold resources
352 */
353void
354nlmsvc_mark_resources(void)
355{
356 dprintk("lockd: nlmsvc_mark_resources\n");
Wendy Cheng17efa372008-01-17 11:10:12 -0500357 nlm_traverse_files(NULL, nlmsvc_mark_host, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358}
359
360/*
361 * Release all resources held by the given client
362 */
363void
364nlmsvc_free_host_resources(struct nlm_host *host)
365{
366 dprintk("lockd: nlmsvc_free_host_resources\n");
367
Wendy Cheng17efa372008-01-17 11:10:12 -0500368 if (nlm_traverse_files(host, nlmsvc_same_host, NULL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 printk(KERN_WARNING
Olaf Kirchf0737a32006-10-04 02:15:54 -0700370 "lockd: couldn't remove all locks held by %s\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 host->h_name);
Olaf Kirchf0737a32006-10-04 02:15:54 -0700372 BUG();
373 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374}
375
Chuck Lever367c8c72008-06-30 18:58:14 -0400376/**
377 * nlmsvc_invalidate_all - remove all locks held for clients
378 *
379 * Release all locks held by NFS clients.
380 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 */
382void
383nlmsvc_invalidate_all(void)
384{
Chuck Lever367c8c72008-06-30 18:58:14 -0400385 /*
Olaf Kirchf2af7932006-10-04 02:15:59 -0700386 * Previously, the code would call
387 * nlmsvc_free_host_resources for each client in
388 * turn, which is about as inefficient as it gets.
389 * Now we just do it once in nlm_traverse_files.
390 */
Wendy Cheng17efa372008-01-17 11:10:12 -0500391 nlm_traverse_files(NULL, nlmsvc_is_client, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392}
Wendy Cheng4373ea82008-01-17 11:10:12 -0500393
394static int
Wendy Cheng17efa372008-01-17 11:10:12 -0500395nlmsvc_match_sb(void *datap, struct nlm_file *file)
396{
397 struct super_block *sb = datap;
398
399 return sb == file->f_file->f_path.mnt->mnt_sb;
400}
401
Chuck Lever367c8c72008-06-30 18:58:14 -0400402/**
403 * nlmsvc_unlock_all_by_sb - release locks held on this file system
404 * @sb: super block
405 *
406 * Release all locks held by clients accessing this file system.
407 */
Wendy Cheng17efa372008-01-17 11:10:12 -0500408int
409nlmsvc_unlock_all_by_sb(struct super_block *sb)
410{
411 int ret;
412
413 ret = nlm_traverse_files(sb, nlmsvc_always_match, nlmsvc_match_sb);
414 return ret ? -EIO : 0;
415}
416EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_sb);
417
418static int
Wendy Cheng4373ea82008-01-17 11:10:12 -0500419nlmsvc_match_ip(void *datap, struct nlm_host *host)
420{
Jeff Layton4516fc02009-08-14 12:57:54 -0400421 return rpc_cmp_addr(nlm_srcaddr(host), datap);
Wendy Cheng4373ea82008-01-17 11:10:12 -0500422}
423
Chuck Lever367c8c72008-06-30 18:58:14 -0400424/**
425 * nlmsvc_unlock_all_by_ip - release local locks by IP address
426 * @server_addr: server's IP address as seen by clients
427 *
428 * Release all locks held by clients accessing this host
429 * via the passed in IP address.
430 */
Wendy Cheng4373ea82008-01-17 11:10:12 -0500431int
Chuck Lever367c8c72008-06-30 18:58:14 -0400432nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr)
Wendy Cheng4373ea82008-01-17 11:10:12 -0500433{
434 int ret;
Wendy Cheng4373ea82008-01-17 11:10:12 -0500435
Chuck Lever367c8c72008-06-30 18:58:14 -0400436 ret = nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL);
437 return ret ? -EIO : 0;
Wendy Cheng4373ea82008-01-17 11:10:12 -0500438}
439EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_ip);