1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/fs/lockd/svcsubs.c
5 * Various support routines for the NLM server.
7 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
10 #include <linux/types.h>
11 #include <linux/string.h>
12 #include <linux/time.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>
24 #define NLMDBG_FACILITY NLMDBG_SVCSUBS
28 * Global file hash table
30 #define FILE_HASH_BITS 7
31 #define FILE_NRHASH (1<<FILE_HASH_BITS)
32 static struct hlist_head nlm_files[FILE_NRHASH];
33 static DEFINE_MUTEX(nlm_file_mutex);
35 #ifdef CONFIG_SUNRPC_DEBUG
36 static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f)
38 u32 *fhp = (u32*)f->data;
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]);
46 static inline void nlm_debug_print_file(char *msg, struct nlm_file *file)
48 struct inode *inode = nlmsvc_file_inode(file);
50 dprintk("lockd: %s %s/%ld\n",
51 msg, inode->i_sb->s_id, inode->i_ino);
54 static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f)
59 static inline void nlm_debug_print_file(char *msg, struct nlm_file *file)
65 static inline unsigned int file_hash(struct nfs_fh *f)
69 for (i=0; i<NFS2_FHSIZE;i++)
71 return tmp & (FILE_NRHASH - 1);
75 * Lookup file info. If it doesn't exist, create a file info struct
76 * and open a (VFS) file for the given inode.
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.
84 nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
85 struct nlm_lock *lock)
87 struct nlm_file *file;
91 nlm_debug_print_fh("nlm_lookup_file", &lock->fh);
93 hash = file_hash(&lock->fh);
96 mutex_lock(&nlm_file_mutex);
98 hlist_for_each_entry(file, &nlm_files[hash], f_list)
99 if (!nfs_compare_fh(&file->f_handle, &lock->fh))
102 nlm_debug_print_fh("creating file for", &lock->fh);
104 nfserr = nlm_lck_denied_nolocks;
105 file = kzalloc(sizeof(*file), GFP_KERNEL);
109 memcpy(&file->f_handle, &lock->fh, sizeof(struct nfs_fh));
110 mutex_init(&file->f_mutex);
111 INIT_HLIST_NODE(&file->f_list);
112 INIT_LIST_HEAD(&file->f_blocks);
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.
117 * We have to make sure we have the right credential to open
120 nfserr = nlmsvc_ops->fopen(rqstp, &lock->fh, &file->f_file);
122 dprintk("lockd: open failed (error %d)\n", nfserr);
126 hlist_add_head(&file->f_list, &nlm_files[hash]);
129 dprintk("lockd: found file %p (count %d)\n", file, file->f_count);
135 mutex_unlock(&nlm_file_mutex);
144 * Delete a file after having released all locks, blocks and shares
147 nlm_delete_file(struct nlm_file *file)
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);
155 printk(KERN_WARNING "lockd: attempt to release unknown file!\n");
160 * Loop over all locks on the given file and perform the specified
164 nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file,
165 nlm_host_match_fn_t match)
167 struct inode *inode = nlmsvc_file_inode(file);
168 struct file_lock *fl;
169 struct file_lock_context *flctx = inode->i_flctx;
170 struct nlm_host *lockhost;
172 if (!flctx || list_empty_careful(&flctx->flc_posix))
176 spin_lock(&flctx->flc_lock);
177 list_for_each_entry(fl, &flctx->flc_posix, fl_list) {
178 if (fl->fl_lmops != &nlmsvc_lock_operations)
181 /* update current lock count */
184 lockhost = ((struct nlm_lockowner *)fl->fl_owner)->host;
185 if (match(lockhost, host)) {
186 struct file_lock lock = *fl;
188 spin_unlock(&flctx->flc_lock);
189 lock.fl_type = F_UNLCK;
191 lock.fl_end = OFFSET_MAX;
192 if (vfs_lock_file(file->f_file, F_SETLK, &lock, NULL) < 0) {
193 printk("lockd: unlock failure in %s:%d\n",
200 spin_unlock(&flctx->flc_lock);
206 nlmsvc_always_match(void *dummy1, struct nlm_host *dummy2)
212 * Inspect a single file
215 nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, nlm_host_match_fn_t match)
217 nlmsvc_traverse_blocks(host, file, match);
218 nlmsvc_traverse_shares(host, file, match);
219 return nlm_traverse_locks(host, file, match);
223 * Quick check whether there are still any locks, blocks or
224 * shares on a given file.
227 nlm_file_inuse(struct nlm_file *file)
229 struct inode *inode = nlmsvc_file_inode(file);
230 struct file_lock *fl;
231 struct file_lock_context *flctx = inode->i_flctx;
233 if (file->f_count || !list_empty(&file->f_blocks) || file->f_shares)
236 if (flctx && !list_empty_careful(&flctx->flc_posix)) {
237 spin_lock(&flctx->flc_lock);
238 list_for_each_entry(fl, &flctx->flc_posix, fl_list) {
239 if (fl->fl_lmops == &nlmsvc_lock_operations) {
240 spin_unlock(&flctx->flc_lock);
244 spin_unlock(&flctx->flc_lock);
251 * Loop over all files in the file table.
254 nlm_traverse_files(void *data, nlm_host_match_fn_t match,
255 int (*is_failover_file)(void *data, struct nlm_file *file))
257 struct hlist_node *next;
258 struct nlm_file *file;
261 mutex_lock(&nlm_file_mutex);
262 for (i = 0; i < FILE_NRHASH; i++) {
263 hlist_for_each_entry_safe(file, next, &nlm_files[i], f_list) {
264 if (is_failover_file && !is_failover_file(data, file))
267 mutex_unlock(&nlm_file_mutex);
269 /* Traverse locks, blocks and shares of this file
270 * and update file->f_locks count */
271 if (nlm_inspect_file(data, file, match))
274 mutex_lock(&nlm_file_mutex);
276 /* No more references to this file. Let go of it. */
277 if (list_empty(&file->f_blocks) && !file->f_locks
278 && !file->f_shares && !file->f_count) {
279 hlist_del(&file->f_list);
280 nlmsvc_ops->fclose(file->f_file);
285 mutex_unlock(&nlm_file_mutex);
290 * Release file. If there are no more remote locks on this file,
291 * close it and free the handle.
293 * Note that we can't do proper reference counting without major
294 * contortions because the code in fs/locks.c creates, deletes and
295 * splits locks without notification. Our only way is to walk the
296 * entire lock list each time we remove a lock.
299 nlm_release_file(struct nlm_file *file)
301 dprintk("lockd: nlm_release_file(%p, ct = %d)\n",
302 file, file->f_count);
304 /* Lock file table */
305 mutex_lock(&nlm_file_mutex);
307 /* If there are no more locks etc, delete the file */
308 if (--file->f_count == 0 && !nlm_file_inuse(file))
309 nlm_delete_file(file);
311 mutex_unlock(&nlm_file_mutex);
315 * Helpers function for resource traversal
318 * used by the garbage collector; simply sets h_inuse only for those
319 * hosts, which passed network check.
323 * returns 1 iff the two hosts match. Used to release
324 * all resources bound to a specific host.
327 * returns 1 iff the host is a client.
328 * Used by nlmsvc_invalidate_all
332 nlmsvc_mark_host(void *data, struct nlm_host *hint)
334 struct nlm_host *host = data;
336 if ((hint->net == NULL) ||
337 (host->net == hint->net))
343 nlmsvc_same_host(void *data, struct nlm_host *other)
345 struct nlm_host *host = data;
347 return host == other;
351 nlmsvc_is_client(void *data, struct nlm_host *dummy)
353 struct nlm_host *host = data;
355 if (host->h_server) {
356 /* we are destroying locks even though the client
357 * hasn't asked us too, so don't unmonitor the
360 if (host->h_nsmhandle)
361 host->h_nsmhandle->sm_sticky = 1;
368 * Mark all hosts that still hold resources
371 nlmsvc_mark_resources(struct net *net)
373 struct nlm_host hint;
375 dprintk("lockd: %s for net %x\n", __func__, net ? net->ns.inum : 0);
377 nlm_traverse_files(&hint, nlmsvc_mark_host, NULL);
381 * Release all resources held by the given client
384 nlmsvc_free_host_resources(struct nlm_host *host)
386 dprintk("lockd: nlmsvc_free_host_resources\n");
388 if (nlm_traverse_files(host, nlmsvc_same_host, NULL)) {
390 "lockd: couldn't remove all locks held by %s\n",
397 * nlmsvc_invalidate_all - remove all locks held for clients
399 * Release all locks held by NFS clients.
403 nlmsvc_invalidate_all(void)
406 * Previously, the code would call
407 * nlmsvc_free_host_resources for each client in
408 * turn, which is about as inefficient as it gets.
409 * Now we just do it once in nlm_traverse_files.
411 nlm_traverse_files(NULL, nlmsvc_is_client, NULL);
415 nlmsvc_match_sb(void *datap, struct nlm_file *file)
417 struct super_block *sb = datap;
419 return sb == nlmsvc_file_inode(file)->i_sb;
423 * nlmsvc_unlock_all_by_sb - release locks held on this file system
426 * Release all locks held by clients accessing this file system.
429 nlmsvc_unlock_all_by_sb(struct super_block *sb)
433 ret = nlm_traverse_files(sb, nlmsvc_always_match, nlmsvc_match_sb);
434 return ret ? -EIO : 0;
436 EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_sb);
439 nlmsvc_match_ip(void *datap, struct nlm_host *host)
441 return rpc_cmp_addr(nlm_srcaddr(host), datap);
445 * nlmsvc_unlock_all_by_ip - release local locks by IP address
446 * @server_addr: server's IP address as seen by clients
448 * Release all locks held by clients accessing this host
449 * via the passed in IP address.
452 nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr)
456 ret = nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL);
457 return ret ? -EIO : 0;
459 EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_ip);