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CommitLineData
1da177e4
LT
1/*
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
1da177e4
LT
9#include <linux/types.h>
10#include <linux/string.h>
11#include <linux/time.h>
12#include <linux/in.h>
5a0e3ad6 13#include <linux/slab.h>
353ab6e9 14#include <linux/mutex.h>
1da177e4
LT
15#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>
4373ea84
WC
21#include <linux/module.h>
22#include <linux/mount.h>
1da177e4
LT
23
24#define NLMDBG_FACILITY NLMDBG_SVCSUBS
25
26
27/*
28 * Global file hash table
29 */
07ba8063 30#define FILE_HASH_BITS 7
1da177e4 31#define FILE_NRHASH (1<<FILE_HASH_BITS)
07ba8063 32static struct hlist_head nlm_files[FILE_NRHASH];
353ab6e9 33static DEFINE_MUTEX(nlm_file_mutex);
1da177e4 34
0bbacc40
CL
35#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{
225a719f 48 struct inode *inode = file->f_file->f_path.dentry->d_inode;
0bbacc40
CL
49
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
1da177e4
LT
65static 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 */
52921e02 83__be32
1da177e4
LT
84nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
85 struct nfs_fh *f)
86{
07ba8063 87 struct hlist_node *pos;
1da177e4
LT
88 struct nlm_file *file;
89 unsigned int hash;
52921e02 90 __be32 nfserr;
1da177e4 91
50431d94 92 nlm_debug_print_fh("nlm_lookup_file", f);
1da177e4
LT
93
94 hash = file_hash(f);
95
96 /* Lock file table */
353ab6e9 97 mutex_lock(&nlm_file_mutex);
1da177e4 98
07ba8063 99 hlist_for_each_entry(file, pos, &nlm_files[hash], f_list)
1da177e4
LT
100 if (!nfs_compare_fh(&file->f_handle, f))
101 goto found;
102
0bbacc40 103 nlm_debug_print_fh("creating file for", f);
1da177e4
LT
104
105 nfserr = nlm_lck_denied_nolocks;
f8314dc6 106 file = kzalloc(sizeof(*file), GFP_KERNEL);
1da177e4
LT
107 if (!file)
108 goto out_unlock;
109
1da177e4 110 memcpy(&file->f_handle, f, sizeof(struct nfs_fh));
89e63ef6 111 mutex_init(&file->f_mutex);
07ba8063 112 INIT_HLIST_NODE(&file->f_list);
68a2d76c 113 INIT_LIST_HEAD(&file->f_blocks);
1da177e4
LT
114
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) {
f0737a39 122 dprintk("lockd: open failed (error %d)\n", nfserr);
1da177e4
LT
123 goto out_free;
124 }
125
07ba8063 126 hlist_add_head(&file->f_list, &nlm_files[hash]);
1da177e4
LT
127
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:
353ab6e9 135 mutex_unlock(&nlm_file_mutex);
1da177e4
LT
136 return nfserr;
137
138out_free:
139 kfree(file);
1da177e4
LT
140 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{
0bbacc40 149 nlm_debug_print_file("closing file", file);
07ba8063
OK
150 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");
1da177e4 156 }
1da177e4
LT
157}
158
159/*
160 * Loop over all locks on the given file and perform the specified
161 * action.
162 */
163static int
f2af793d
OK
164nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file,
165 nlm_host_match_fn_t match)
1da177e4
LT
166{
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;
763641d8 173 lock_flocks(); /* protects i_flock list */
1da177e4 174 for (fl = inode->i_flock; fl; fl = fl->fl_next) {
7117bf3d 175 if (fl->fl_lmops != &nlmsvc_lock_operations)
1da177e4
LT
176 continue;
177
178 /* update current lock count */
179 file->f_locks++;
f2af793d 180
1da177e4 181 lockhost = (struct nlm_host *) fl->fl_owner;
f2af793d 182 if (match(lockhost, host)) {
1da177e4
LT
183 struct file_lock lock = *fl;
184
763641d8 185 unlock_flocks();
1da177e4
LT
186 lock.fl_type = F_UNLCK;
187 lock.fl_start = 0;
188 lock.fl_end = OFFSET_MAX;
1a8322b2 189 if (vfs_lock_file(file->f_file, F_SETLK, &lock, NULL) < 0) {
1da177e4
LT
190 printk("lockd: unlock failure in %s:%d\n",
191 __FILE__, __LINE__);
192 return 1;
193 }
194 goto again;
195 }
196 }
763641d8 197 unlock_flocks();
1da177e4
LT
198
199 return 0;
200}
201
17efa372
WC
202static int
203nlmsvc_always_match(void *dummy1, struct nlm_host *dummy2)
204{
205 return 1;
206}
207
1da177e4 208/*
f2af793d
OK
209 * Inspect a single file
210 */
211static inline int
212nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, nlm_host_match_fn_t match)
213{
214 nlmsvc_traverse_blocks(host, file, match);
215 nlmsvc_traverse_shares(host, file, match);
216 return nlm_traverse_locks(host, file, match);
217}
218
219/*
220 * Quick check whether there are still any locks, blocks or
221 * shares on a given file.
1da177e4
LT
222 */
223static inline int
f2af793d 224nlm_file_inuse(struct nlm_file *file)
1da177e4 225{
f2af793d
OK
226 struct inode *inode = nlmsvc_file_inode(file);
227 struct file_lock *fl;
228
229 if (file->f_count || !list_empty(&file->f_blocks) || file->f_shares)
230 return 1;
231
763641d8 232 lock_flocks();
f2af793d 233 for (fl = inode->i_flock; fl; fl = fl->fl_next) {
763641d8
AB
234 if (fl->fl_lmops == &nlmsvc_lock_operations) {
235 unlock_flocks();
1da177e4 236 return 1;
763641d8 237 }
1da177e4 238 }
763641d8 239 unlock_flocks();
f2af793d
OK
240 file->f_locks = 0;
241 return 0;
1da177e4
LT
242}
243
244/*
245 * Loop over all files in the file table.
246 */
247static int
17efa372
WC
248nlm_traverse_files(void *data, nlm_host_match_fn_t match,
249 int (*is_failover_file)(void *data, struct nlm_file *file))
1da177e4 250{
07ba8063
OK
251 struct hlist_node *pos, *next;
252 struct nlm_file *file;
01df9c5e 253 int i, ret = 0;
1da177e4 254
353ab6e9 255 mutex_lock(&nlm_file_mutex);
1da177e4 256 for (i = 0; i < FILE_NRHASH; i++) {
07ba8063 257 hlist_for_each_entry_safe(file, pos, next, &nlm_files[i], f_list) {
17efa372
WC
258 if (is_failover_file && !is_failover_file(data, file))
259 continue;
01df9c5e
TM
260 file->f_count++;
261 mutex_unlock(&nlm_file_mutex);
262
1da177e4
LT
263 /* Traverse locks, blocks and shares of this file
264 * and update file->f_locks count */
4373ea84 265 if (nlm_inspect_file(data, file, match))
01df9c5e 266 ret = 1;
1da177e4 267
01df9c5e
TM
268 mutex_lock(&nlm_file_mutex);
269 file->f_count--;
1da177e4 270 /* No more references to this file. Let go of it. */
68a2d76c 271 if (list_empty(&file->f_blocks) && !file->f_locks
1da177e4 272 && !file->f_shares && !file->f_count) {
07ba8063 273 hlist_del(&file->f_list);
1da177e4
LT
274 nlmsvc_ops->fclose(file->f_file);
275 kfree(file);
1da177e4
LT
276 }
277 }
278 }
353ab6e9 279 mutex_unlock(&nlm_file_mutex);
01df9c5e 280 return ret;
1da177e4
LT
281}
282
283/*
284 * Release file. If there are no more remote locks on this file,
285 * close it and free the handle.
286 *
287 * Note that we can't do proper reference counting without major
288 * contortions because the code in fs/locks.c creates, deletes and
289 * splits locks without notification. Our only way is to walk the
290 * entire lock list each time we remove a lock.
291 */
292void
293nlm_release_file(struct nlm_file *file)
294{
295 dprintk("lockd: nlm_release_file(%p, ct = %d)\n",
296 file, file->f_count);
297
298 /* Lock file table */
353ab6e9 299 mutex_lock(&nlm_file_mutex);
1da177e4
LT
300
301 /* If there are no more locks etc, delete the file */
f2af793d
OK
302 if (--file->f_count == 0 && !nlm_file_inuse(file))
303 nlm_delete_file(file);
1da177e4 304
353ab6e9 305 mutex_unlock(&nlm_file_mutex);
1da177e4
LT
306}
307
f2af793d
OK
308/*
309 * Helpers function for resource traversal
310 *
311 * nlmsvc_mark_host:
312 * used by the garbage collector; simply sets h_inuse.
313 * Always returns 0.
314 *
315 * nlmsvc_same_host:
316 * returns 1 iff the two hosts match. Used to release
317 * all resources bound to a specific host.
318 *
319 * nlmsvc_is_client:
320 * returns 1 iff the host is a client.
321 * Used by nlmsvc_invalidate_all
322 */
323static int
4373ea84 324nlmsvc_mark_host(void *data, struct nlm_host *dummy)
f2af793d 325{
4373ea84
WC
326 struct nlm_host *host = data;
327
f2af793d
OK
328 host->h_inuse = 1;
329 return 0;
330}
331
332static int
4373ea84 333nlmsvc_same_host(void *data, struct nlm_host *other)
f2af793d 334{
4373ea84
WC
335 struct nlm_host *host = data;
336
f2af793d
OK
337 return host == other;
338}
339
340static int
4373ea84 341nlmsvc_is_client(void *data, struct nlm_host *dummy)
f2af793d 342{
4373ea84
WC
343 struct nlm_host *host = data;
344
4481d103
N
345 if (host->h_server) {
346 /* we are destroying locks even though the client
347 * hasn't asked us too, so don't unmonitor the
348 * client
349 */
350 if (host->h_nsmhandle)
351 host->h_nsmhandle->sm_sticky = 1;
352 return 1;
353 } else
354 return 0;
f2af793d
OK
355}
356
1da177e4
LT
357/*
358 * Mark all hosts that still hold resources
359 */
360void
361nlmsvc_mark_resources(void)
362{
363 dprintk("lockd: nlmsvc_mark_resources\n");
17efa372 364 nlm_traverse_files(NULL, nlmsvc_mark_host, NULL);
1da177e4
LT
365}
366
367/*
368 * Release all resources held by the given client
369 */
370void
371nlmsvc_free_host_resources(struct nlm_host *host)
372{
373 dprintk("lockd: nlmsvc_free_host_resources\n");
374
17efa372 375 if (nlm_traverse_files(host, nlmsvc_same_host, NULL)) {
1da177e4 376 printk(KERN_WARNING
f0737a39 377 "lockd: couldn't remove all locks held by %s\n",
1da177e4 378 host->h_name);
f0737a39
OK
379 BUG();
380 }
1da177e4
LT
381}
382
367c8c7b
CL
383/**
384 * nlmsvc_invalidate_all - remove all locks held for clients
385 *
386 * Release all locks held by NFS clients.
387 *
1da177e4
LT
388 */
389void
390nlmsvc_invalidate_all(void)
391{
367c8c7b 392 /*
f2af793d
OK
393 * Previously, the code would call
394 * nlmsvc_free_host_resources for each client in
395 * turn, which is about as inefficient as it gets.
396 * Now we just do it once in nlm_traverse_files.
397 */
17efa372
WC
398 nlm_traverse_files(NULL, nlmsvc_is_client, NULL);
399}
400
401static int
402nlmsvc_match_sb(void *datap, struct nlm_file *file)
403{
404 struct super_block *sb = datap;
405
406 return sb == file->f_file->f_path.mnt->mnt_sb;
407}
408
367c8c7b
CL
409/**
410 * nlmsvc_unlock_all_by_sb - release locks held on this file system
411 * @sb: super block
412 *
413 * Release all locks held by clients accessing this file system.
414 */
17efa372
WC
415int
416nlmsvc_unlock_all_by_sb(struct super_block *sb)
417{
418 int ret;
419
420 ret = nlm_traverse_files(sb, nlmsvc_always_match, nlmsvc_match_sb);
421 return ret ? -EIO : 0;
1da177e4 422}
17efa372 423EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_sb);
4373ea84
WC
424
425static int
426nlmsvc_match_ip(void *datap, struct nlm_host *host)
427{
4516fc04 428 return rpc_cmp_addr(nlm_srcaddr(host), datap);
4373ea84
WC
429}
430
367c8c7b
CL
431/**
432 * nlmsvc_unlock_all_by_ip - release local locks by IP address
433 * @server_addr: server's IP address as seen by clients
434 *
435 * Release all locks held by clients accessing this host
436 * via the passed in IP address.
437 */
4373ea84 438int
367c8c7b 439nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr)
4373ea84
WC
440{
441 int ret;
4373ea84 442
367c8c7b
CL
443 ret = nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL);
444 return ret ? -EIO : 0;
4373ea84
WC
445}
446EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_ip);