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Commit | Line | Data |
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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> | |
353ab6e9 | 13 | #include <linux/mutex.h> |
1da177e4 LT |
14 | #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> | |
20 | #include <linux/lockd/sm_inter.h> | |
21 | ||
22 | #define NLMDBG_FACILITY NLMDBG_SVCSUBS | |
23 | ||
24 | ||
25 | /* | |
26 | * Global file hash table | |
27 | */ | |
07ba8063 | 28 | #define FILE_HASH_BITS 7 |
1da177e4 | 29 | #define FILE_NRHASH (1<<FILE_HASH_BITS) |
07ba8063 | 30 | static struct hlist_head nlm_files[FILE_NRHASH]; |
353ab6e9 | 31 | static DEFINE_MUTEX(nlm_file_mutex); |
1da177e4 | 32 | |
0bbacc40 CL |
33 | #ifdef NFSD_DEBUG |
34 | static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f) | |
35 | { | |
36 | u32 *fhp = (u32*)f->data; | |
37 | ||
38 | /* print the first 32 bytes of the fh */ | |
39 | dprintk("lockd: %s (%08x %08x %08x %08x %08x %08x %08x %08x)\n", | |
40 | msg, fhp[0], fhp[1], fhp[2], fhp[3], | |
41 | fhp[4], fhp[5], fhp[6], fhp[7]); | |
42 | } | |
43 | ||
44 | static inline void nlm_debug_print_file(char *msg, struct nlm_file *file) | |
45 | { | |
225a719f | 46 | struct inode *inode = file->f_file->f_path.dentry->d_inode; |
0bbacc40 CL |
47 | |
48 | dprintk("lockd: %s %s/%ld\n", | |
49 | msg, inode->i_sb->s_id, inode->i_ino); | |
50 | } | |
51 | #else | |
52 | static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f) | |
53 | { | |
54 | return; | |
55 | } | |
56 | ||
57 | static inline void nlm_debug_print_file(char *msg, struct nlm_file *file) | |
58 | { | |
59 | return; | |
60 | } | |
61 | #endif | |
62 | ||
1da177e4 LT |
63 | static inline unsigned int file_hash(struct nfs_fh *f) |
64 | { | |
65 | unsigned int tmp=0; | |
66 | int i; | |
67 | for (i=0; i<NFS2_FHSIZE;i++) | |
68 | tmp += f->data[i]; | |
69 | return tmp & (FILE_NRHASH - 1); | |
70 | } | |
71 | ||
72 | /* | |
73 | * Lookup file info. If it doesn't exist, create a file info struct | |
74 | * and open a (VFS) file for the given inode. | |
75 | * | |
76 | * FIXME: | |
77 | * Note that we open the file O_RDONLY even when creating write locks. | |
78 | * This is not quite right, but for now, we assume the client performs | |
79 | * the proper R/W checking. | |
80 | */ | |
52921e02 | 81 | __be32 |
1da177e4 LT |
82 | nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result, |
83 | struct nfs_fh *f) | |
84 | { | |
07ba8063 | 85 | struct hlist_node *pos; |
1da177e4 LT |
86 | struct nlm_file *file; |
87 | unsigned int hash; | |
52921e02 | 88 | __be32 nfserr; |
1da177e4 | 89 | |
0bbacc40 | 90 | nlm_debug_print_fh("nlm_file_lookup", f); |
1da177e4 LT |
91 | |
92 | hash = file_hash(f); | |
93 | ||
94 | /* Lock file table */ | |
353ab6e9 | 95 | mutex_lock(&nlm_file_mutex); |
1da177e4 | 96 | |
07ba8063 | 97 | hlist_for_each_entry(file, pos, &nlm_files[hash], f_list) |
1da177e4 LT |
98 | if (!nfs_compare_fh(&file->f_handle, f)) |
99 | goto found; | |
100 | ||
0bbacc40 | 101 | nlm_debug_print_fh("creating file for", f); |
1da177e4 LT |
102 | |
103 | nfserr = nlm_lck_denied_nolocks; | |
f8314dc6 | 104 | file = kzalloc(sizeof(*file), GFP_KERNEL); |
1da177e4 LT |
105 | if (!file) |
106 | goto out_unlock; | |
107 | ||
1da177e4 | 108 | memcpy(&file->f_handle, f, sizeof(struct nfs_fh)); |
89e63ef6 | 109 | mutex_init(&file->f_mutex); |
07ba8063 | 110 | INIT_HLIST_NODE(&file->f_list); |
68a2d76c | 111 | INIT_LIST_HEAD(&file->f_blocks); |
1da177e4 LT |
112 | |
113 | /* Open the file. Note that this must not sleep for too long, else | |
114 | * we would lock up lockd:-) So no NFS re-exports, folks. | |
115 | * | |
116 | * We have to make sure we have the right credential to open | |
117 | * the file. | |
118 | */ | |
119 | if ((nfserr = nlmsvc_ops->fopen(rqstp, f, &file->f_file)) != 0) { | |
f0737a39 | 120 | dprintk("lockd: open failed (error %d)\n", nfserr); |
1da177e4 LT |
121 | goto out_free; |
122 | } | |
123 | ||
07ba8063 | 124 | hlist_add_head(&file->f_list, &nlm_files[hash]); |
1da177e4 LT |
125 | |
126 | found: | |
127 | dprintk("lockd: found file %p (count %d)\n", file, file->f_count); | |
128 | *result = file; | |
129 | file->f_count++; | |
130 | nfserr = 0; | |
131 | ||
132 | out_unlock: | |
353ab6e9 | 133 | mutex_unlock(&nlm_file_mutex); |
1da177e4 LT |
134 | return nfserr; |
135 | ||
136 | out_free: | |
137 | kfree(file); | |
1da177e4 LT |
138 | goto out_unlock; |
139 | } | |
140 | ||
141 | /* | |
142 | * Delete a file after having released all locks, blocks and shares | |
143 | */ | |
144 | static inline void | |
145 | nlm_delete_file(struct nlm_file *file) | |
146 | { | |
0bbacc40 | 147 | nlm_debug_print_file("closing file", file); |
07ba8063 OK |
148 | if (!hlist_unhashed(&file->f_list)) { |
149 | hlist_del(&file->f_list); | |
150 | nlmsvc_ops->fclose(file->f_file); | |
151 | kfree(file); | |
152 | } else { | |
153 | printk(KERN_WARNING "lockd: attempt to release unknown file!\n"); | |
1da177e4 | 154 | } |
1da177e4 LT |
155 | } |
156 | ||
157 | /* | |
158 | * Loop over all locks on the given file and perform the specified | |
159 | * action. | |
160 | */ | |
161 | static int | |
f2af793d OK |
162 | nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file, |
163 | nlm_host_match_fn_t match) | |
1da177e4 LT |
164 | { |
165 | struct inode *inode = nlmsvc_file_inode(file); | |
166 | struct file_lock *fl; | |
167 | struct nlm_host *lockhost; | |
168 | ||
169 | again: | |
170 | file->f_locks = 0; | |
171 | for (fl = inode->i_flock; fl; fl = fl->fl_next) { | |
7117bf3d | 172 | if (fl->fl_lmops != &nlmsvc_lock_operations) |
1da177e4 LT |
173 | continue; |
174 | ||
175 | /* update current lock count */ | |
176 | file->f_locks++; | |
f2af793d | 177 | |
1da177e4 | 178 | lockhost = (struct nlm_host *) fl->fl_owner; |
f2af793d | 179 | if (match(lockhost, host)) { |
1da177e4 LT |
180 | struct file_lock lock = *fl; |
181 | ||
1da177e4 LT |
182 | lock.fl_type = F_UNLCK; |
183 | lock.fl_start = 0; | |
184 | lock.fl_end = OFFSET_MAX; | |
185 | if (posix_lock_file(file->f_file, &lock) < 0) { | |
186 | printk("lockd: unlock failure in %s:%d\n", | |
187 | __FILE__, __LINE__); | |
188 | return 1; | |
189 | } | |
190 | goto again; | |
191 | } | |
192 | } | |
193 | ||
194 | return 0; | |
195 | } | |
196 | ||
197 | /* | |
f2af793d OK |
198 | * Inspect a single file |
199 | */ | |
200 | static inline int | |
201 | nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, nlm_host_match_fn_t match) | |
202 | { | |
203 | nlmsvc_traverse_blocks(host, file, match); | |
204 | nlmsvc_traverse_shares(host, file, match); | |
205 | return nlm_traverse_locks(host, file, match); | |
206 | } | |
207 | ||
208 | /* | |
209 | * Quick check whether there are still any locks, blocks or | |
210 | * shares on a given file. | |
1da177e4 LT |
211 | */ |
212 | static inline int | |
f2af793d | 213 | nlm_file_inuse(struct nlm_file *file) |
1da177e4 | 214 | { |
f2af793d OK |
215 | struct inode *inode = nlmsvc_file_inode(file); |
216 | struct file_lock *fl; | |
217 | ||
218 | if (file->f_count || !list_empty(&file->f_blocks) || file->f_shares) | |
219 | return 1; | |
220 | ||
221 | for (fl = inode->i_flock; fl; fl = fl->fl_next) { | |
222 | if (fl->fl_lmops == &nlmsvc_lock_operations) | |
1da177e4 | 223 | return 1; |
1da177e4 | 224 | } |
f2af793d OK |
225 | file->f_locks = 0; |
226 | return 0; | |
1da177e4 LT |
227 | } |
228 | ||
229 | /* | |
230 | * Loop over all files in the file table. | |
231 | */ | |
232 | static int | |
f2af793d | 233 | nlm_traverse_files(struct nlm_host *host, nlm_host_match_fn_t match) |
1da177e4 | 234 | { |
07ba8063 OK |
235 | struct hlist_node *pos, *next; |
236 | struct nlm_file *file; | |
01df9c5e | 237 | int i, ret = 0; |
1da177e4 | 238 | |
353ab6e9 | 239 | mutex_lock(&nlm_file_mutex); |
1da177e4 | 240 | for (i = 0; i < FILE_NRHASH; i++) { |
07ba8063 | 241 | hlist_for_each_entry_safe(file, pos, next, &nlm_files[i], f_list) { |
01df9c5e TM |
242 | file->f_count++; |
243 | mutex_unlock(&nlm_file_mutex); | |
244 | ||
1da177e4 LT |
245 | /* Traverse locks, blocks and shares of this file |
246 | * and update file->f_locks count */ | |
f2af793d | 247 | if (nlm_inspect_file(host, file, match)) |
01df9c5e | 248 | ret = 1; |
1da177e4 | 249 | |
01df9c5e TM |
250 | mutex_lock(&nlm_file_mutex); |
251 | file->f_count--; | |
1da177e4 | 252 | /* No more references to this file. Let go of it. */ |
68a2d76c | 253 | if (list_empty(&file->f_blocks) && !file->f_locks |
1da177e4 | 254 | && !file->f_shares && !file->f_count) { |
07ba8063 | 255 | hlist_del(&file->f_list); |
1da177e4 LT |
256 | nlmsvc_ops->fclose(file->f_file); |
257 | kfree(file); | |
1da177e4 LT |
258 | } |
259 | } | |
260 | } | |
353ab6e9 | 261 | mutex_unlock(&nlm_file_mutex); |
01df9c5e | 262 | return ret; |
1da177e4 LT |
263 | } |
264 | ||
265 | /* | |
266 | * Release file. If there are no more remote locks on this file, | |
267 | * close it and free the handle. | |
268 | * | |
269 | * Note that we can't do proper reference counting without major | |
270 | * contortions because the code in fs/locks.c creates, deletes and | |
271 | * splits locks without notification. Our only way is to walk the | |
272 | * entire lock list each time we remove a lock. | |
273 | */ | |
274 | void | |
275 | nlm_release_file(struct nlm_file *file) | |
276 | { | |
277 | dprintk("lockd: nlm_release_file(%p, ct = %d)\n", | |
278 | file, file->f_count); | |
279 | ||
280 | /* Lock file table */ | |
353ab6e9 | 281 | mutex_lock(&nlm_file_mutex); |
1da177e4 LT |
282 | |
283 | /* If there are no more locks etc, delete the file */ | |
f2af793d OK |
284 | if (--file->f_count == 0 && !nlm_file_inuse(file)) |
285 | nlm_delete_file(file); | |
1da177e4 | 286 | |
353ab6e9 | 287 | mutex_unlock(&nlm_file_mutex); |
1da177e4 LT |
288 | } |
289 | ||
f2af793d OK |
290 | /* |
291 | * Helpers function for resource traversal | |
292 | * | |
293 | * nlmsvc_mark_host: | |
294 | * used by the garbage collector; simply sets h_inuse. | |
295 | * Always returns 0. | |
296 | * | |
297 | * nlmsvc_same_host: | |
298 | * returns 1 iff the two hosts match. Used to release | |
299 | * all resources bound to a specific host. | |
300 | * | |
301 | * nlmsvc_is_client: | |
302 | * returns 1 iff the host is a client. | |
303 | * Used by nlmsvc_invalidate_all | |
304 | */ | |
305 | static int | |
306 | nlmsvc_mark_host(struct nlm_host *host, struct nlm_host *dummy) | |
307 | { | |
308 | host->h_inuse = 1; | |
309 | return 0; | |
310 | } | |
311 | ||
312 | static int | |
313 | nlmsvc_same_host(struct nlm_host *host, struct nlm_host *other) | |
314 | { | |
315 | return host == other; | |
316 | } | |
317 | ||
318 | static int | |
319 | nlmsvc_is_client(struct nlm_host *host, struct nlm_host *dummy) | |
320 | { | |
4481d103 N |
321 | if (host->h_server) { |
322 | /* we are destroying locks even though the client | |
323 | * hasn't asked us too, so don't unmonitor the | |
324 | * client | |
325 | */ | |
326 | if (host->h_nsmhandle) | |
327 | host->h_nsmhandle->sm_sticky = 1; | |
328 | return 1; | |
329 | } else | |
330 | return 0; | |
f2af793d OK |
331 | } |
332 | ||
1da177e4 LT |
333 | /* |
334 | * Mark all hosts that still hold resources | |
335 | */ | |
336 | void | |
337 | nlmsvc_mark_resources(void) | |
338 | { | |
339 | dprintk("lockd: nlmsvc_mark_resources\n"); | |
f2af793d | 340 | nlm_traverse_files(NULL, nlmsvc_mark_host); |
1da177e4 LT |
341 | } |
342 | ||
343 | /* | |
344 | * Release all resources held by the given client | |
345 | */ | |
346 | void | |
347 | nlmsvc_free_host_resources(struct nlm_host *host) | |
348 | { | |
349 | dprintk("lockd: nlmsvc_free_host_resources\n"); | |
350 | ||
f2af793d | 351 | if (nlm_traverse_files(host, nlmsvc_same_host)) { |
1da177e4 | 352 | printk(KERN_WARNING |
f0737a39 | 353 | "lockd: couldn't remove all locks held by %s\n", |
1da177e4 | 354 | host->h_name); |
f0737a39 OK |
355 | BUG(); |
356 | } | |
1da177e4 LT |
357 | } |
358 | ||
359 | /* | |
350fce8d | 360 | * Remove all locks held for clients |
1da177e4 LT |
361 | */ |
362 | void | |
363 | nlmsvc_invalidate_all(void) | |
364 | { | |
f2af793d OK |
365 | /* Release all locks held by NFS clients. |
366 | * Previously, the code would call | |
367 | * nlmsvc_free_host_resources for each client in | |
368 | * turn, which is about as inefficient as it gets. | |
369 | * Now we just do it once in nlm_traverse_files. | |
370 | */ | |
371 | nlm_traverse_files(NULL, nlmsvc_is_client); | |
1da177e4 | 372 | } |