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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
9#include <linux/types.h>
10#include <linux/string.h>
11#include <linux/time.h>
12#include <linux/in.h>
13#include <linux/slab.h>
14#include <linux/mutex.h>
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>
21#include <linux/module.h>
22#include <linux/mount.h>
23
24#define NLMDBG_FACILITY NLMDBG_SVCSUBS
25
26
27/*
28 * Global file hash table
29 */
30#define FILE_HASH_BITS 7
31#define FILE_NRHASH (1<<FILE_HASH_BITS)
32static struct hlist_head nlm_files[FILE_NRHASH];
33static DEFINE_MUTEX(nlm_file_mutex);
34
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{
48 struct inode *inode = file->f_file->f_path.dentry->d_inode;
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
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 */
83__be32
84nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
85 struct nfs_fh *f)
86{
87 struct hlist_node *pos;
88 struct nlm_file *file;
89 unsigned int hash;
90 __be32 nfserr;
91
92 nlm_debug_print_fh("nlm_lookup_file", f);
93
94 hash = file_hash(f);
95
96 /* Lock file table */
97 mutex_lock(&nlm_file_mutex);
98
99 hlist_for_each_entry(file, pos, &nlm_files[hash], f_list)
100 if (!nfs_compare_fh(&file->f_handle, f))
101 goto found;
102
103 nlm_debug_print_fh("creating file for", f);
104
105 nfserr = nlm_lck_denied_nolocks;
106 file = kzalloc(sizeof(*file), GFP_KERNEL);
107 if (!file)
108 goto out_unlock;
109
110 memcpy(&file->f_handle, f, sizeof(struct nfs_fh));
111 mutex_init(&file->f_mutex);
112 INIT_HLIST_NODE(&file->f_list);
113 INIT_LIST_HEAD(&file->f_blocks);
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) {
122 dprintk("lockd: open failed (error %d)\n", nfserr);
123 goto out_free;
124 }
125
126 hlist_add_head(&file->f_list, &nlm_files[hash]);
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:
135 mutex_unlock(&nlm_file_mutex);
136 return nfserr;
137
138out_free:
139 kfree(file);
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{
149 nlm_debug_print_file("closing file", file);
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");
156 }
157}
158
159/*
160 * Loop over all locks on the given file and perform the specified
161 * action.
162 */
163static int
164nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file,
165 nlm_host_match_fn_t match)
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;
173 lock_flocks(); /* protects i_flock list */
174 for (fl = inode->i_flock; fl; fl = fl->fl_next) {
175 if (fl->fl_lmops != &nlmsvc_lock_operations)
176 continue;
177
178 /* update current lock count */
179 file->f_locks++;
180
181 lockhost = (struct nlm_host *) fl->fl_owner;
182 if (match(lockhost, host)) {
183 struct file_lock lock = *fl;
184
185 unlock_flocks();
186 lock.fl_type = F_UNLCK;
187 lock.fl_start = 0;
188 lock.fl_end = OFFSET_MAX;
189 if (vfs_lock_file(file->f_file, F_SETLK, &lock, NULL) < 0) {
190 printk("lockd: unlock failure in %s:%d\n",
191 __FILE__, __LINE__);
192 return 1;
193 }
194 goto again;
195 }
196 }
197 unlock_flocks();
198
199 return 0;
200}
201
202static int
203nlmsvc_always_match(void *dummy1, struct nlm_host *dummy2)
204{
205 return 1;
206}
207
208/*
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.
222 */
223static inline int
224nlm_file_inuse(struct nlm_file *file)
225{
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
232 lock_flocks();
233 for (fl = inode->i_flock; fl; fl = fl->fl_next) {
234 if (fl->fl_lmops == &nlmsvc_lock_operations) {
235 unlock_flocks();
236 return 1;
237 }
238 }
239 unlock_flocks();
240 file->f_locks = 0;
241 return 0;
242}
243
244/*
245 * Loop over all files in the file table.
246 */
247static int
248nlm_traverse_files(void *data, nlm_host_match_fn_t match,
249 int (*is_failover_file)(void *data, struct nlm_file *file))
250{
251 struct hlist_node *pos, *next;
252 struct nlm_file *file;
253 int i, ret = 0;
254
255 mutex_lock(&nlm_file_mutex);
256 for (i = 0; i < FILE_NRHASH; i++) {
257 hlist_for_each_entry_safe(file, pos, next, &nlm_files[i], f_list) {
258 if (is_failover_file && !is_failover_file(data, file))
259 continue;
260 file->f_count++;
261 mutex_unlock(&nlm_file_mutex);
262
263 /* Traverse locks, blocks and shares of this file
264 * and update file->f_locks count */
265 if (nlm_inspect_file(data, file, match))
266 ret = 1;
267
268 mutex_lock(&nlm_file_mutex);
269 file->f_count--;
270 /* No more references to this file. Let go of it. */
271 if (list_empty(&file->f_blocks) && !file->f_locks
272 && !file->f_shares && !file->f_count) {
273 hlist_del(&file->f_list);
274 nlmsvc_ops->fclose(file->f_file);
275 kfree(file);
276 }
277 }
278 }
279 mutex_unlock(&nlm_file_mutex);
280 return ret;
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 */
299 mutex_lock(&nlm_file_mutex);
300
301 /* If there are no more locks etc, delete the file */
302 if (--file->f_count == 0 && !nlm_file_inuse(file))
303 nlm_delete_file(file);
304
305 mutex_unlock(&nlm_file_mutex);
306}
307
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
324nlmsvc_mark_host(void *data, struct nlm_host *dummy)
325{
326 struct nlm_host *host = data;
327
328 host->h_inuse = 1;
329 return 0;
330}
331
332static int
333nlmsvc_same_host(void *data, struct nlm_host *other)
334{
335 struct nlm_host *host = data;
336
337 return host == other;
338}
339
340static int
341nlmsvc_is_client(void *data, struct nlm_host *dummy)
342{
343 struct nlm_host *host = data;
344
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;
355}
356
357/*
358 * Mark all hosts that still hold resources
359 */
360void
361nlmsvc_mark_resources(void)
362{
363 dprintk("lockd: nlmsvc_mark_resources\n");
364 nlm_traverse_files(NULL, nlmsvc_mark_host, NULL);
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
375 if (nlm_traverse_files(host, nlmsvc_same_host, NULL)) {
376 printk(KERN_WARNING
377 "lockd: couldn't remove all locks held by %s\n",
378 host->h_name);
379 BUG();
380 }
381}
382
383/**
384 * nlmsvc_invalidate_all - remove all locks held for clients
385 *
386 * Release all locks held by NFS clients.
387 *
388 */
389void
390nlmsvc_invalidate_all(void)
391{
392 /*
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 */
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
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 */
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;
422}
423EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_sb);
424
425static int
426nlmsvc_match_ip(void *datap, struct nlm_host *host)
427{
428 return rpc_cmp_addr(nlm_srcaddr(host), datap);
429}
430
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 */
438int
439nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr)
440{
441 int ret;
442
443 ret = nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL);
444 return ret ? -EIO : 0;
445}
446EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_ip);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/fs/lockd/svcsubs.c
4 *
5 * Various support routines for the NLM server.
6 *
7 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
8 */
9
10#include <linux/types.h>
11#include <linux/string.h>
12#include <linux/time.h>
13#include <linux/in.h>
14#include <linux/slab.h>
15#include <linux/mutex.h>
16#include <linux/sunrpc/svc.h>
17#include <linux/sunrpc/addr.h>
18#include <linux/lockd/lockd.h>
19#include <linux/lockd/share.h>
20#include <linux/module.h>
21#include <linux/mount.h>
22#include <uapi/linux/nfs2.h>
23
24#define NLMDBG_FACILITY NLMDBG_SVCSUBS
25
26
27/*
28 * Global file hash table
29 */
30#define FILE_HASH_BITS 7
31#define FILE_NRHASH (1<<FILE_HASH_BITS)
32static struct hlist_head nlm_files[FILE_NRHASH];
33static DEFINE_MUTEX(nlm_file_mutex);
34
35#ifdef CONFIG_SUNRPC_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{
48 struct inode *inode = nlmsvc_file_inode(file);
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
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
74int lock_to_openmode(struct file_lock *lock)
75{
76 return lock_is_write(lock) ? O_WRONLY : O_RDONLY;
77}
78
79/*
80 * Open the file. Note that if we're reexporting, for example,
81 * this could block the lockd thread for a while.
82 *
83 * We have to make sure we have the right credential to open
84 * the file.
85 */
86static __be32 nlm_do_fopen(struct svc_rqst *rqstp,
87 struct nlm_file *file, int mode)
88{
89 struct file **fp = &file->f_file[mode];
90 __be32 nfserr;
91
92 if (*fp)
93 return 0;
94 nfserr = nlmsvc_ops->fopen(rqstp, &file->f_handle, fp, mode);
95 if (nfserr)
96 dprintk("lockd: open failed (error %d)\n", nfserr);
97 return nfserr;
98}
99
100/*
101 * Lookup file info. If it doesn't exist, create a file info struct
102 * and open a (VFS) file for the given inode.
103 */
104__be32
105nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
106 struct nlm_lock *lock)
107{
108 struct nlm_file *file;
109 unsigned int hash;
110 __be32 nfserr;
111 int mode;
112
113 nlm_debug_print_fh("nlm_lookup_file", &lock->fh);
114
115 hash = file_hash(&lock->fh);
116 mode = lock_to_openmode(&lock->fl);
117
118 /* Lock file table */
119 mutex_lock(&nlm_file_mutex);
120
121 hlist_for_each_entry(file, &nlm_files[hash], f_list)
122 if (!nfs_compare_fh(&file->f_handle, &lock->fh)) {
123 mutex_lock(&file->f_mutex);
124 nfserr = nlm_do_fopen(rqstp, file, mode);
125 mutex_unlock(&file->f_mutex);
126 goto found;
127 }
128 nlm_debug_print_fh("creating file for", &lock->fh);
129
130 nfserr = nlm_lck_denied_nolocks;
131 file = kzalloc(sizeof(*file), GFP_KERNEL);
132 if (!file)
133 goto out_free;
134
135 memcpy(&file->f_handle, &lock->fh, sizeof(struct nfs_fh));
136 mutex_init(&file->f_mutex);
137 INIT_HLIST_NODE(&file->f_list);
138 INIT_LIST_HEAD(&file->f_blocks);
139
140 nfserr = nlm_do_fopen(rqstp, file, mode);
141 if (nfserr)
142 goto out_unlock;
143
144 hlist_add_head(&file->f_list, &nlm_files[hash]);
145
146found:
147 dprintk("lockd: found file %p (count %d)\n", file, file->f_count);
148 *result = file;
149 file->f_count++;
150
151out_unlock:
152 mutex_unlock(&nlm_file_mutex);
153 return nfserr;
154
155out_free:
156 kfree(file);
157 goto out_unlock;
158}
159
160/*
161 * Delete a file after having released all locks, blocks and shares
162 */
163static inline void
164nlm_delete_file(struct nlm_file *file)
165{
166 nlm_debug_print_file("closing file", file);
167 if (!hlist_unhashed(&file->f_list)) {
168 hlist_del(&file->f_list);
169 if (file->f_file[O_RDONLY])
170 nlmsvc_ops->fclose(file->f_file[O_RDONLY]);
171 if (file->f_file[O_WRONLY])
172 nlmsvc_ops->fclose(file->f_file[O_WRONLY]);
173 kfree(file);
174 } else {
175 printk(KERN_WARNING "lockd: attempt to release unknown file!\n");
176 }
177}
178
179static int nlm_unlock_files(struct nlm_file *file, const struct file_lock *fl)
180{
181 struct file_lock lock;
182
183 locks_init_lock(&lock);
184 lock.c.flc_type = F_UNLCK;
185 lock.fl_start = 0;
186 lock.fl_end = OFFSET_MAX;
187 lock.c.flc_owner = fl->c.flc_owner;
188 lock.c.flc_pid = fl->c.flc_pid;
189 lock.c.flc_flags = FL_POSIX;
190
191 lock.c.flc_file = file->f_file[O_RDONLY];
192 if (lock.c.flc_file && vfs_lock_file(lock.c.flc_file, F_SETLK, &lock, NULL))
193 goto out_err;
194 lock.c.flc_file = file->f_file[O_WRONLY];
195 if (lock.c.flc_file && vfs_lock_file(lock.c.flc_file, F_SETLK, &lock, NULL))
196 goto out_err;
197 return 0;
198out_err:
199 pr_warn("lockd: unlock failure in %s:%d\n", __FILE__, __LINE__);
200 return 1;
201}
202
203/*
204 * Loop over all locks on the given file and perform the specified
205 * action.
206 */
207static int
208nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file,
209 nlm_host_match_fn_t match)
210{
211 struct inode *inode = nlmsvc_file_inode(file);
212 struct file_lock *fl;
213 struct file_lock_context *flctx = locks_inode_context(inode);
214 struct nlm_host *lockhost;
215
216 if (!flctx || list_empty_careful(&flctx->flc_posix))
217 return 0;
218again:
219 file->f_locks = 0;
220 spin_lock(&flctx->flc_lock);
221 for_each_file_lock(fl, &flctx->flc_posix) {
222 if (fl->fl_lmops != &nlmsvc_lock_operations)
223 continue;
224
225 /* update current lock count */
226 file->f_locks++;
227
228 lockhost = ((struct nlm_lockowner *) fl->c.flc_owner)->host;
229 if (match(lockhost, host)) {
230
231 spin_unlock(&flctx->flc_lock);
232 if (nlm_unlock_files(file, fl))
233 return 1;
234 goto again;
235 }
236 }
237 spin_unlock(&flctx->flc_lock);
238
239 return 0;
240}
241
242static int
243nlmsvc_always_match(void *dummy1, struct nlm_host *dummy2)
244{
245 return 1;
246}
247
248/*
249 * Inspect a single file
250 */
251static inline int
252nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, nlm_host_match_fn_t match)
253{
254 nlmsvc_traverse_blocks(host, file, match);
255 nlmsvc_traverse_shares(host, file, match);
256 return nlm_traverse_locks(host, file, match);
257}
258
259/*
260 * Quick check whether there are still any locks, blocks or
261 * shares on a given file.
262 */
263static inline int
264nlm_file_inuse(struct nlm_file *file)
265{
266 struct inode *inode = nlmsvc_file_inode(file);
267 struct file_lock *fl;
268 struct file_lock_context *flctx = locks_inode_context(inode);
269
270 if (file->f_count || !list_empty(&file->f_blocks) || file->f_shares)
271 return 1;
272
273 if (flctx && !list_empty_careful(&flctx->flc_posix)) {
274 spin_lock(&flctx->flc_lock);
275 for_each_file_lock(fl, &flctx->flc_posix) {
276 if (fl->fl_lmops == &nlmsvc_lock_operations) {
277 spin_unlock(&flctx->flc_lock);
278 return 1;
279 }
280 }
281 spin_unlock(&flctx->flc_lock);
282 }
283 file->f_locks = 0;
284 return 0;
285}
286
287static void nlm_close_files(struct nlm_file *file)
288{
289 if (file->f_file[O_RDONLY])
290 nlmsvc_ops->fclose(file->f_file[O_RDONLY]);
291 if (file->f_file[O_WRONLY])
292 nlmsvc_ops->fclose(file->f_file[O_WRONLY]);
293}
294
295/*
296 * Loop over all files in the file table.
297 */
298static int
299nlm_traverse_files(void *data, nlm_host_match_fn_t match,
300 int (*is_failover_file)(void *data, struct nlm_file *file))
301{
302 struct hlist_node *next;
303 struct nlm_file *file;
304 int i, ret = 0;
305
306 mutex_lock(&nlm_file_mutex);
307 for (i = 0; i < FILE_NRHASH; i++) {
308 hlist_for_each_entry_safe(file, next, &nlm_files[i], f_list) {
309 if (is_failover_file && !is_failover_file(data, file))
310 continue;
311 file->f_count++;
312 mutex_unlock(&nlm_file_mutex);
313
314 /* Traverse locks, blocks and shares of this file
315 * and update file->f_locks count */
316 if (nlm_inspect_file(data, file, match))
317 ret = 1;
318
319 mutex_lock(&nlm_file_mutex);
320 file->f_count--;
321 /* No more references to this file. Let go of it. */
322 if (list_empty(&file->f_blocks) && !file->f_locks
323 && !file->f_shares && !file->f_count) {
324 hlist_del(&file->f_list);
325 nlm_close_files(file);
326 kfree(file);
327 }
328 }
329 }
330 mutex_unlock(&nlm_file_mutex);
331 return ret;
332}
333
334/*
335 * Release file. If there are no more remote locks on this file,
336 * close it and free the handle.
337 *
338 * Note that we can't do proper reference counting without major
339 * contortions because the code in fs/locks.c creates, deletes and
340 * splits locks without notification. Our only way is to walk the
341 * entire lock list each time we remove a lock.
342 */
343void
344nlm_release_file(struct nlm_file *file)
345{
346 dprintk("lockd: nlm_release_file(%p, ct = %d)\n",
347 file, file->f_count);
348
349 /* Lock file table */
350 mutex_lock(&nlm_file_mutex);
351
352 /* If there are no more locks etc, delete the file */
353 if (--file->f_count == 0 && !nlm_file_inuse(file))
354 nlm_delete_file(file);
355
356 mutex_unlock(&nlm_file_mutex);
357}
358
359/*
360 * Helpers function for resource traversal
361 *
362 * nlmsvc_mark_host:
363 * used by the garbage collector; simply sets h_inuse only for those
364 * hosts, which passed network check.
365 * Always returns 0.
366 *
367 * nlmsvc_same_host:
368 * returns 1 iff the two hosts match. Used to release
369 * all resources bound to a specific host.
370 *
371 * nlmsvc_is_client:
372 * returns 1 iff the host is a client.
373 * Used by nlmsvc_invalidate_all
374 */
375
376static int
377nlmsvc_mark_host(void *data, struct nlm_host *hint)
378{
379 struct nlm_host *host = data;
380
381 if ((hint->net == NULL) ||
382 (host->net == hint->net))
383 host->h_inuse = 1;
384 return 0;
385}
386
387static int
388nlmsvc_same_host(void *data, struct nlm_host *other)
389{
390 struct nlm_host *host = data;
391
392 return host == other;
393}
394
395static int
396nlmsvc_is_client(void *data, struct nlm_host *dummy)
397{
398 struct nlm_host *host = data;
399
400 if (host->h_server) {
401 /* we are destroying locks even though the client
402 * hasn't asked us too, so don't unmonitor the
403 * client
404 */
405 if (host->h_nsmhandle)
406 host->h_nsmhandle->sm_sticky = 1;
407 return 1;
408 } else
409 return 0;
410}
411
412/*
413 * Mark all hosts that still hold resources
414 */
415void
416nlmsvc_mark_resources(struct net *net)
417{
418 struct nlm_host hint;
419
420 dprintk("lockd: %s for net %x\n", __func__, net ? net->ns.inum : 0);
421 hint.net = net;
422 nlm_traverse_files(&hint, nlmsvc_mark_host, NULL);
423}
424
425/*
426 * Release all resources held by the given client
427 */
428void
429nlmsvc_free_host_resources(struct nlm_host *host)
430{
431 dprintk("lockd: nlmsvc_free_host_resources\n");
432
433 if (nlm_traverse_files(host, nlmsvc_same_host, NULL)) {
434 printk(KERN_WARNING
435 "lockd: couldn't remove all locks held by %s\n",
436 host->h_name);
437 BUG();
438 }
439}
440
441/**
442 * nlmsvc_invalidate_all - remove all locks held for clients
443 *
444 * Release all locks held by NFS clients.
445 *
446 */
447void
448nlmsvc_invalidate_all(void)
449{
450 /*
451 * Previously, the code would call
452 * nlmsvc_free_host_resources for each client in
453 * turn, which is about as inefficient as it gets.
454 * Now we just do it once in nlm_traverse_files.
455 */
456 nlm_traverse_files(NULL, nlmsvc_is_client, NULL);
457}
458
459
460static int
461nlmsvc_match_sb(void *datap, struct nlm_file *file)
462{
463 struct super_block *sb = datap;
464
465 return sb == nlmsvc_file_inode(file)->i_sb;
466}
467
468/**
469 * nlmsvc_unlock_all_by_sb - release locks held on this file system
470 * @sb: super block
471 *
472 * Release all locks held by clients accessing this file system.
473 */
474int
475nlmsvc_unlock_all_by_sb(struct super_block *sb)
476{
477 int ret;
478
479 ret = nlm_traverse_files(sb, nlmsvc_always_match, nlmsvc_match_sb);
480 return ret ? -EIO : 0;
481}
482EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_sb);
483
484static int
485nlmsvc_match_ip(void *datap, struct nlm_host *host)
486{
487 return rpc_cmp_addr(nlm_srcaddr(host), datap);
488}
489
490/**
491 * nlmsvc_unlock_all_by_ip - release local locks by IP address
492 * @server_addr: server's IP address as seen by clients
493 *
494 * Release all locks held by clients accessing this host
495 * via the passed in IP address.
496 */
497int
498nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr)
499{
500 int ret;
501
502 ret = nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL);
503 return ret ? -EIO : 0;
504}
505EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_ip);