Linux Audio

Check our new training course

Loading...
v3.1
 
  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);
v5.14.15
  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 = locks_inode(file->f_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
 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 nlm_file	*file;
 88	unsigned int	hash;
 89	__be32		nfserr;
 90
 91	nlm_debug_print_fh("nlm_lookup_file", f);
 92
 93	hash = file_hash(f);
 94
 95	/* Lock file table */
 96	mutex_lock(&nlm_file_mutex);
 97
 98	hlist_for_each_entry(file, &nlm_files[hash], f_list)
 99		if (!nfs_compare_fh(&file->f_handle, f))
100			goto found;
101
102	nlm_debug_print_fh("creating file for", f);
103
104	nfserr = nlm_lck_denied_nolocks;
105	file = kzalloc(sizeof(*file), GFP_KERNEL);
106	if (!file)
107		goto out_unlock;
108
109	memcpy(&file->f_handle, f, sizeof(struct nfs_fh));
110	mutex_init(&file->f_mutex);
111	INIT_HLIST_NODE(&file->f_list);
112	INIT_LIST_HEAD(&file->f_blocks);
113
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.
116	 *
117	 * We have to make sure we have the right credential to open
118	 * the file.
119	 */
120	if ((nfserr = nlmsvc_ops->fopen(rqstp, f, &file->f_file)) != 0) {
121		dprintk("lockd: open failed (error %d)\n", nfserr);
122		goto out_free;
123	}
124
125	hlist_add_head(&file->f_list, &nlm_files[hash]);
126
127found:
128	dprintk("lockd: found file %p (count %d)\n", file, file->f_count);
129	*result = file;
130	file->f_count++;
131	nfserr = 0;
132
133out_unlock:
134	mutex_unlock(&nlm_file_mutex);
135	return nfserr;
136
137out_free:
138	kfree(file);
139	goto out_unlock;
140}
141
142/*
143 * Delete a file after having released all locks, blocks and shares
144 */
145static inline void
146nlm_delete_file(struct nlm_file *file)
147{
148	nlm_debug_print_file("closing file", file);
149	if (!hlist_unhashed(&file->f_list)) {
150		hlist_del(&file->f_list);
151		nlmsvc_ops->fclose(file->f_file);
152		kfree(file);
153	} else {
154		printk(KERN_WARNING "lockd: attempt to release unknown file!\n");
155	}
156}
157
158/*
159 * Loop over all locks on the given file and perform the specified
160 * action.
161 */
162static int
163nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file,
164			nlm_host_match_fn_t match)
165{
166	struct inode	 *inode = nlmsvc_file_inode(file);
167	struct file_lock *fl;
168	struct file_lock_context *flctx = inode->i_flctx;
169	struct nlm_host	 *lockhost;
170
171	if (!flctx || list_empty_careful(&flctx->flc_posix))
172		return 0;
173again:
174	file->f_locks = 0;
175	spin_lock(&flctx->flc_lock);
176	list_for_each_entry(fl, &flctx->flc_posix, fl_list) {
177		if (fl->fl_lmops != &nlmsvc_lock_operations)
178			continue;
179
180		/* update current lock count */
181		file->f_locks++;
182
183		lockhost = ((struct nlm_lockowner *)fl->fl_owner)->host;
184		if (match(lockhost, host)) {
185			struct file_lock lock = *fl;
186
187			spin_unlock(&flctx->flc_lock);
188			lock.fl_type  = F_UNLCK;
189			lock.fl_start = 0;
190			lock.fl_end   = OFFSET_MAX;
191			if (vfs_lock_file(file->f_file, F_SETLK, &lock, NULL) < 0) {
192				printk("lockd: unlock failure in %s:%d\n",
193						__FILE__, __LINE__);
194				return 1;
195			}
196			goto again;
197		}
198	}
199	spin_unlock(&flctx->flc_lock);
200
201	return 0;
202}
203
204static int
205nlmsvc_always_match(void *dummy1, struct nlm_host *dummy2)
206{
207	return 1;
208}
209
210/*
211 * Inspect a single file
212 */
213static inline int
214nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, nlm_host_match_fn_t match)
215{
216	nlmsvc_traverse_blocks(host, file, match);
217	nlmsvc_traverse_shares(host, file, match);
218	return nlm_traverse_locks(host, file, match);
219}
220
221/*
222 * Quick check whether there are still any locks, blocks or
223 * shares on a given file.
224 */
225static inline int
226nlm_file_inuse(struct nlm_file *file)
227{
228	struct inode	 *inode = nlmsvc_file_inode(file);
229	struct file_lock *fl;
230	struct file_lock_context *flctx = inode->i_flctx;
231
232	if (file->f_count || !list_empty(&file->f_blocks) || file->f_shares)
233		return 1;
234
235	if (flctx && !list_empty_careful(&flctx->flc_posix)) {
236		spin_lock(&flctx->flc_lock);
237		list_for_each_entry(fl, &flctx->flc_posix, fl_list) {
238			if (fl->fl_lmops == &nlmsvc_lock_operations) {
239				spin_unlock(&flctx->flc_lock);
240				return 1;
241			}
242		}
243		spin_unlock(&flctx->flc_lock);
244	}
 
245	file->f_locks = 0;
246	return 0;
247}
248
249/*
250 * Loop over all files in the file table.
251 */
252static int
253nlm_traverse_files(void *data, nlm_host_match_fn_t match,
254		int (*is_failover_file)(void *data, struct nlm_file *file))
255{
256	struct hlist_node *next;
257	struct nlm_file	*file;
258	int i, ret = 0;
259
260	mutex_lock(&nlm_file_mutex);
261	for (i = 0; i < FILE_NRHASH; i++) {
262		hlist_for_each_entry_safe(file, next, &nlm_files[i], f_list) {
263			if (is_failover_file && !is_failover_file(data, file))
264				continue;
265			file->f_count++;
266			mutex_unlock(&nlm_file_mutex);
267
268			/* Traverse locks, blocks and shares of this file
269			 * and update file->f_locks count */
270			if (nlm_inspect_file(data, file, match))
271				ret = 1;
272
273			mutex_lock(&nlm_file_mutex);
274			file->f_count--;
275			/* No more references to this file. Let go of it. */
276			if (list_empty(&file->f_blocks) && !file->f_locks
277			 && !file->f_shares && !file->f_count) {
278				hlist_del(&file->f_list);
279				nlmsvc_ops->fclose(file->f_file);
280				kfree(file);
281			}
282		}
283	}
284	mutex_unlock(&nlm_file_mutex);
285	return ret;
286}
287
288/*
289 * Release file. If there are no more remote locks on this file,
290 * close it and free the handle.
291 *
292 * Note that we can't do proper reference counting without major
293 * contortions because the code in fs/locks.c creates, deletes and
294 * splits locks without notification. Our only way is to walk the
295 * entire lock list each time we remove a lock.
296 */
297void
298nlm_release_file(struct nlm_file *file)
299{
300	dprintk("lockd: nlm_release_file(%p, ct = %d)\n",
301				file, file->f_count);
302
303	/* Lock file table */
304	mutex_lock(&nlm_file_mutex);
305
306	/* If there are no more locks etc, delete the file */
307	if (--file->f_count == 0 && !nlm_file_inuse(file))
308		nlm_delete_file(file);
309
310	mutex_unlock(&nlm_file_mutex);
311}
312
313/*
314 * Helpers function for resource traversal
315 *
316 * nlmsvc_mark_host:
317 *	used by the garbage collector; simply sets h_inuse only for those
318 *	hosts, which passed network check.
319 *	Always returns 0.
320 *
321 * nlmsvc_same_host:
322 *	returns 1 iff the two hosts match. Used to release
323 *	all resources bound to a specific host.
324 *
325 * nlmsvc_is_client:
326 *	returns 1 iff the host is a client.
327 *	Used by nlmsvc_invalidate_all
328 */
329
330static int
331nlmsvc_mark_host(void *data, struct nlm_host *hint)
332{
333	struct nlm_host *host = data;
334
335	if ((hint->net == NULL) ||
336	    (host->net == hint->net))
337		host->h_inuse = 1;
338	return 0;
339}
340
341static int
342nlmsvc_same_host(void *data, struct nlm_host *other)
343{
344	struct nlm_host *host = data;
345
346	return host == other;
347}
348
349static int
350nlmsvc_is_client(void *data, struct nlm_host *dummy)
351{
352	struct nlm_host *host = data;
353
354	if (host->h_server) {
355		/* we are destroying locks even though the client
356		 * hasn't asked us too, so don't unmonitor the
357		 * client
358		 */
359		if (host->h_nsmhandle)
360			host->h_nsmhandle->sm_sticky = 1;
361		return 1;
362	} else
363		return 0;
364}
365
366/*
367 * Mark all hosts that still hold resources
368 */
369void
370nlmsvc_mark_resources(struct net *net)
371{
372	struct nlm_host hint;
373
374	dprintk("lockd: %s for net %x\n", __func__, net ? net->ns.inum : 0);
375	hint.net = net;
376	nlm_traverse_files(&hint, nlmsvc_mark_host, NULL);
377}
378
379/*
380 * Release all resources held by the given client
381 */
382void
383nlmsvc_free_host_resources(struct nlm_host *host)
384{
385	dprintk("lockd: nlmsvc_free_host_resources\n");
386
387	if (nlm_traverse_files(host, nlmsvc_same_host, NULL)) {
388		printk(KERN_WARNING
389			"lockd: couldn't remove all locks held by %s\n",
390			host->h_name);
391		BUG();
392	}
393}
394
395/**
396 * nlmsvc_invalidate_all - remove all locks held for clients
397 *
398 * Release all locks held by NFS clients.
399 *
400 */
401void
402nlmsvc_invalidate_all(void)
403{
404	/*
405	 * Previously, the code would call
406	 * nlmsvc_free_host_resources for each client in
407	 * turn, which is about as inefficient as it gets.
408	 * Now we just do it once in nlm_traverse_files.
409	 */
410	nlm_traverse_files(NULL, nlmsvc_is_client, NULL);
411}
412
413static int
414nlmsvc_match_sb(void *datap, struct nlm_file *file)
415{
416	struct super_block *sb = datap;
417
418	return sb == locks_inode(file->f_file)->i_sb;
419}
420
421/**
422 * nlmsvc_unlock_all_by_sb - release locks held on this file system
423 * @sb: super block
424 *
425 * Release all locks held by clients accessing this file system.
426 */
427int
428nlmsvc_unlock_all_by_sb(struct super_block *sb)
429{
430	int ret;
431
432	ret = nlm_traverse_files(sb, nlmsvc_always_match, nlmsvc_match_sb);
433	return ret ? -EIO : 0;
434}
435EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_sb);
436
437static int
438nlmsvc_match_ip(void *datap, struct nlm_host *host)
439{
440	return rpc_cmp_addr(nlm_srcaddr(host), datap);
441}
442
443/**
444 * nlmsvc_unlock_all_by_ip - release local locks by IP address
445 * @server_addr: server's IP address as seen by clients
446 *
447 * Release all locks held by clients accessing this host
448 * via the passed in IP address.
449 */
450int
451nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr)
452{
453	int ret;
454
455	ret = nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL);
456	return ret ? -EIO : 0;
457}
458EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_ip);