[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / lockd / svcsubs.c

/*
 * linux/fs/lockd/svcsubs.c
 *
 * Various support routines for the NLM server.
 *
 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/types.h>
#include <linux/string.h>
#include <linux/time.h>
#include <linux/in.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfsd/nfsfh.h>
#include <linux/nfsd/export.h>
#include <linux/lockd/lockd.h>
#include <linux/lockd/share.h>
#include <linux/module.h>
#include <linux/mount.h>

#define NLMDBG_FACILITY		NLMDBG_SVCSUBS


/*
 * Global file hash table
 */
#define FILE_HASH_BITS		7
#define FILE_NRHASH		(1<<FILE_HASH_BITS)
static struct hlist_head	nlm_files[FILE_NRHASH];
static DEFINE_MUTEX(nlm_file_mutex);

#ifdef NFSD_DEBUG
static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f)
{
	u32 *fhp = (u32*)f->data;

	/* print the first 32 bytes of the fh */
	dprintk("lockd: %s (%08x %08x %08x %08x %08x %08x %08x %08x)\n",
		msg, fhp[0], fhp[1], fhp[2], fhp[3],
		fhp[4], fhp[5], fhp[6], fhp[7]);
}

static inline void nlm_debug_print_file(char *msg, struct nlm_file *file)
{
	struct inode *inode = file->f_file->f_path.dentry->d_inode;

	dprintk("lockd: %s %s/%ld\n",
		msg, inode->i_sb->s_id, inode->i_ino);
}
#else
static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f)
{
	return;
}

static inline void nlm_debug_print_file(char *msg, struct nlm_file *file)
{
	return;
}
#endif

static inline unsigned int file_hash(struct nfs_fh *f)
{
	unsigned int tmp=0;
	int i;
	for (i=0; i<NFS2_FHSIZE;i++)
		tmp += f->data[i];
	return tmp & (FILE_NRHASH - 1);
}

/*
 * Lookup file info. If it doesn't exist, create a file info struct
 * and open a (VFS) file for the given inode.
 *
 * FIXME:
 * Note that we open the file O_RDONLY even when creating write locks.
 * This is not quite right, but for now, we assume the client performs
 * the proper R/W checking.
 */
__be32
nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
					struct nfs_fh *f)
{
	struct hlist_node *pos;
	struct nlm_file	*file;
	unsigned int	hash;
	__be32		nfserr;

	nlm_debug_print_fh("nlm_lookup_file", f);

	hash = file_hash(f);

	/* Lock file table */
	mutex_lock(&nlm_file_mutex);

	hlist_for_each_entry(file, pos, &nlm_files[hash], f_list)
		if (!nfs_compare_fh(&file->f_handle, f))
			goto found;

	nlm_debug_print_fh("creating file for", f);

	nfserr = nlm_lck_denied_nolocks;
	file = kzalloc(sizeof(*file), GFP_KERNEL);
	if (!file)
		goto out_unlock;

	memcpy(&file->f_handle, f, sizeof(struct nfs_fh));
	mutex_init(&file->f_mutex);
	INIT_HLIST_NODE(&file->f_list);
	INIT_LIST_HEAD(&file->f_blocks);

	/* Open the file. Note that this must not sleep for too long, else
	 * we would lock up lockd:-) So no NFS re-exports, folks.
	 *
	 * We have to make sure we have the right credential to open
	 * the file.
	 */
	if ((nfserr = nlmsvc_ops->fopen(rqstp, f, &file->f_file)) != 0) {
		dprintk("lockd: open failed (error %d)\n", nfserr);
		goto out_free;
	}

	hlist_add_head(&file->f_list, &nlm_files[hash]);

found:
	dprintk("lockd: found file %p (count %d)\n", file, file->f_count);
	*result = file;
	file->f_count++;
	nfserr = 0;

out_unlock:
	mutex_unlock(&nlm_file_mutex);
	return nfserr;

out_free:
	kfree(file);
	goto out_unlock;
}

/*
 * Delete a file after having released all locks, blocks and shares
 */
static inline void
nlm_delete_file(struct nlm_file *file)
{
	nlm_debug_print_file("closing file", file);
	if (!hlist_unhashed(&file->f_list)) {
		hlist_del(&file->f_list);
		nlmsvc_ops->fclose(file->f_file);
		kfree(file);
	} else {
		printk(KERN_WARNING "lockd: attempt to release unknown file!\n");
	}
}

/*
 * Loop over all locks on the given file and perform the specified
 * action.
 */
static int
nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file,
			nlm_host_match_fn_t match)
{
	struct inode	 *inode = nlmsvc_file_inode(file);
	struct file_lock *fl;
	struct nlm_host	 *lockhost;

again:
	file->f_locks = 0;
	for (fl = inode->i_flock; fl; fl = fl->fl_next) {
		if (fl->fl_lmops != &nlmsvc_lock_operations)
			continue;

		/* update current lock count */
		file->f_locks++;

		lockhost = (struct nlm_host *) fl->fl_owner;
		if (match(lockhost, host)) {
			struct file_lock lock = *fl;

			lock.fl_type  = F_UNLCK;
			lock.fl_start = 0;
			lock.fl_end   = OFFSET_MAX;
			if (vfs_lock_file(file->f_file, F_SETLK, &lock, NULL) < 0) {
				printk("lockd: unlock failure in %s:%d\n",
						__FILE__, __LINE__);
				return 1;
			}
			goto again;
		}
	}

	return 0;
}

static int
nlmsvc_always_match(void *dummy1, struct nlm_host *dummy2)
{
	return 1;
}

/*
 * Inspect a single file
 */
static inline int
nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, nlm_host_match_fn_t match)
{
	nlmsvc_traverse_blocks(host, file, match);
	nlmsvc_traverse_shares(host, file, match);
	return nlm_traverse_locks(host, file, match);
}

/*
 * Quick check whether there are still any locks, blocks or
 * shares on a given file.
 */
static inline int
nlm_file_inuse(struct nlm_file *file)
{
	struct inode	 *inode = nlmsvc_file_inode(file);
	struct file_lock *fl;

	if (file->f_count || !list_empty(&file->f_blocks) || file->f_shares)
		return 1;

	for (fl = inode->i_flock; fl; fl = fl->fl_next) {
		if (fl->fl_lmops == &nlmsvc_lock_operations)
			return 1;
	}
	file->f_locks = 0;
	return 0;
}

/*
 * Loop over all files in the file table.
 */
static int
nlm_traverse_files(void *data, nlm_host_match_fn_t match,
		int (*is_failover_file)(void *data, struct nlm_file *file))
{
	struct hlist_node *pos, *next;
	struct nlm_file	*file;
	int i, ret = 0;

	mutex_lock(&nlm_file_mutex);
	for (i = 0; i < FILE_NRHASH; i++) {
		hlist_for_each_entry_safe(file, pos, next, &nlm_files[i], f_list) {
			if (is_failover_file && !is_failover_file(data, file))
				continue;
			file->f_count++;
			mutex_unlock(&nlm_file_mutex);

			/* Traverse locks, blocks and shares of this file
			 * and update file->f_locks count */
			if (nlm_inspect_file(data, file, match))
				ret = 1;

			mutex_lock(&nlm_file_mutex);
			file->f_count--;
			/* No more references to this file. Let go of it. */
			if (list_empty(&file->f_blocks) && !file->f_locks
			 && !file->f_shares && !file->f_count) {
				hlist_del(&file->f_list);
				nlmsvc_ops->fclose(file->f_file);
				kfree(file);
			}
		}
	}
	mutex_unlock(&nlm_file_mutex);
	return ret;
}

/*
 * Release file. If there are no more remote locks on this file,
 * close it and free the handle.
 *
 * Note that we can't do proper reference counting without major
 * contortions because the code in fs/locks.c creates, deletes and
 * splits locks without notification. Our only way is to walk the
 * entire lock list each time we remove a lock.
 */
void
nlm_release_file(struct nlm_file *file)
{
	dprintk("lockd: nlm_release_file(%p, ct = %d)\n",
				file, file->f_count);

	/* Lock file table */
	mutex_lock(&nlm_file_mutex);

	/* If there are no more locks etc, delete the file */
	if (--file->f_count == 0 && !nlm_file_inuse(file))
		nlm_delete_file(file);

	mutex_unlock(&nlm_file_mutex);
}

/*
 * Helpers function for resource traversal
 *
 * nlmsvc_mark_host:
 *	used by the garbage collector; simply sets h_inuse.
 *	Always returns 0.
 *
 * nlmsvc_same_host:
 *	returns 1 iff the two hosts match. Used to release
 *	all resources bound to a specific host.
 *
 * nlmsvc_is_client:
 *	returns 1 iff the host is a client.
 *	Used by nlmsvc_invalidate_all
 */
static int
nlmsvc_mark_host(void *data, struct nlm_host *dummy)
{
	struct nlm_host *host = data;

	host->h_inuse = 1;
	return 0;
}

static int
nlmsvc_same_host(void *data, struct nlm_host *other)
{
	struct nlm_host *host = data;

	return host == other;
}

static int
nlmsvc_is_client(void *data, struct nlm_host *dummy)
{
	struct nlm_host *host = data;

	if (host->h_server) {
		/* we are destroying locks even though the client
		 * hasn't asked us too, so don't unmonitor the
		 * client
		 */
		if (host->h_nsmhandle)
			host->h_nsmhandle->sm_sticky = 1;
		return 1;
	} else
		return 0;
}

/*
 * Mark all hosts that still hold resources
 */
void
nlmsvc_mark_resources(void)
{
	dprintk("lockd: nlmsvc_mark_resources\n");
	nlm_traverse_files(NULL, nlmsvc_mark_host, NULL);
}

/*
 * Release all resources held by the given client
 */
void
nlmsvc_free_host_resources(struct nlm_host *host)
{
	dprintk("lockd: nlmsvc_free_host_resources\n");

	if (nlm_traverse_files(host, nlmsvc_same_host, NULL)) {
		printk(KERN_WARNING
			"lockd: couldn't remove all locks held by %s\n",
			host->h_name);
		BUG();
	}
}

/**
 * nlmsvc_invalidate_all - remove all locks held for clients
 *
 * Release all locks held by NFS clients.
 *
 */
void
nlmsvc_invalidate_all(void)
{
	/*
	 * Previously, the code would call
	 * nlmsvc_free_host_resources for each client in
	 * turn, which is about as inefficient as it gets.
	 * Now we just do it once in nlm_traverse_files.
	 */
	nlm_traverse_files(NULL, nlmsvc_is_client, NULL);
}

static int
nlmsvc_match_sb(void *datap, struct nlm_file *file)
{
	struct super_block *sb = datap;

	return sb == file->f_file->f_path.mnt->mnt_sb;
}

/**
 * nlmsvc_unlock_all_by_sb - release locks held on this file system
 * @sb: super block
 *
 * Release all locks held by clients accessing this file system.
 */
int
nlmsvc_unlock_all_by_sb(struct super_block *sb)
{
	int ret;

	ret = nlm_traverse_files(sb, nlmsvc_always_match, nlmsvc_match_sb);
	return ret ? -EIO : 0;
}
EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_sb);

static int
nlmsvc_match_ip(void *datap, struct nlm_host *host)
{
	return rpc_cmp_addr(nlm_srcaddr(host), datap);
}

/**
 * nlmsvc_unlock_all_by_ip - release local locks by IP address
 * @server_addr: server's IP address as seen by clients
 *
 * Release all locks held by clients accessing this host
 * via the passed in IP address.
 */
int
nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr)
{
	int ret;

	ret = nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL);
	return ret ? -EIO : 0;
}
EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_ip);
Commit	Line	Data
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>
4373ea84 WC	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	32	static struct hlist_head nlm_files[FILE_NRHASH];
353ab6e9	33	static DEFINE_MUTEX(nlm_file_mutex);
1da177e4	34
0bbacc40 CL	35	#ifdef NFSD_DEBUG
	36	static 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
	46	static 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
	54	static inline void nlm_debug_print_fh(char msg, struct nfs_fh f)
	55	{
	56	return;
	57	}
	58
	59	static inline void nlm_debug_print_file(char msg, struct nlm_file file)
	60	{
	61	return;
	62	}
	63	#endif
	64
1da177e4 LT	65	static 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	84	nlm_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;
1da177e4 LT	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
1da177e4 LT	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
	128	found:
	129	dprintk("lockd: found file %p (count %d)\n", file, file->f_count);
	130	*result = file;
	131	file->f_count++;
	132	nfserr = 0;
	133
	134	out_unlock:
353ab6e9	135	mutex_unlock(&nlm_file_mutex);
1da177e4 LT	136	return nfserr;
	137
	138	out_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	*/
	146	static inline void
	147	nlm_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	*/
	163	static int
f2af793d OK	164	nlm_traverse_locks(struct nlm_host host, struct nlm_file file,
f2af793d OK	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
	171	again:
	172	file->f_locks = 0;
	173	for (fl = inode->i_flock; fl; fl = fl->fl_next) {
7117bf3d	174	if (fl->fl_lmops != &nlmsvc_lock_operations)
1da177e4 LT	175	continue;
	176
	177	/* update current lock count */
	178	file->f_locks++;
f2af793d	179
1da177e4	180	lockhost = (struct nlm_host *) fl->fl_owner;
f2af793d	181	if (match(lockhost, host)) {
1da177e4 LT	182	struct file_lock lock = *fl;
1da177e4 LT	183
1da177e4 LT	184	lock.fl_type = F_UNLCK;
	185	lock.fl_start = 0;
	186	lock.fl_end = OFFSET_MAX;
1a8322b2	187	if (vfs_lock_file(file->f_file, F_SETLK, &lock, NULL) < 0) {
1da177e4 LT	188	printk("lockd: unlock failure in %s:%d\n",
	189	__FILE__, __LINE__);
	190	return 1;
	191	}
	192	goto again;
	193	}
	194	}
	195
	196	return 0;
	197	}
	198
17efa372 WC	199	static int
	200	nlmsvc_always_match(void dummy1, struct nlm_host dummy2)
	201	{
	202	return 1;
	203	}
	204
1da177e4	205	/*
f2af793d OK	206	* Inspect a single file
	207	*/
	208	static inline int
	209	nlm_inspect_file(struct nlm_host host, struct nlm_file file, nlm_host_match_fn_t match)
	210	{
	211	nlmsvc_traverse_blocks(host, file, match);
	212	nlmsvc_traverse_shares(host, file, match);
	213	return nlm_traverse_locks(host, file, match);
	214	}
	215
	216	/*
	217	* Quick check whether there are still any locks, blocks or
	218	* shares on a given file.
1da177e4 LT	219	*/
1da177e4 LT	220	static inline int
f2af793d	221	nlm_file_inuse(struct nlm_file *file)
1da177e4	222	{
f2af793d OK	223	struct inode *inode = nlmsvc_file_inode(file);
	224	struct file_lock *fl;
	225
	226	if (file->f_count \|\| !list_empty(&file->f_blocks) \|\| file->f_shares)
	227	return 1;
	228
	229	for (fl = inode->i_flock; fl; fl = fl->fl_next) {
	230	if (fl->fl_lmops == &nlmsvc_lock_operations)
1da177e4	231	return 1;
1da177e4	232	}
f2af793d OK	233	file->f_locks = 0;
f2af793d OK	234	return 0;
1da177e4 LT	235	}
	236
	237	/*
	238	* Loop over all files in the file table.
	239	*/
	240	static int
17efa372 WC	241	nlm_traverse_files(void *data, nlm_host_match_fn_t match,
17efa372 WC	242	int (is_failover_file)(void data, struct nlm_file *file))
1da177e4	243	{
07ba8063 OK	244	struct hlist_node pos, next;
07ba8063 OK	245	struct nlm_file *file;
01df9c5e	246	int i, ret = 0;
1da177e4	247
353ab6e9	248	mutex_lock(&nlm_file_mutex);
1da177e4	249	for (i = 0; i < FILE_NRHASH; i++) {
07ba8063	250	hlist_for_each_entry_safe(file, pos, next, &nlm_files[i], f_list) {
17efa372 WC	251	if (is_failover_file && !is_failover_file(data, file))
17efa372 WC	252	continue;
01df9c5e TM	253	file->f_count++;
	254	mutex_unlock(&nlm_file_mutex);
	255
1da177e4 LT	256	/* Traverse locks, blocks and shares of this file
1da177e4 LT	257	* and update file->f_locks count */
4373ea84	258	if (nlm_inspect_file(data, file, match))
01df9c5e	259	ret = 1;
1da177e4	260
01df9c5e TM	261	mutex_lock(&nlm_file_mutex);
01df9c5e TM	262	file->f_count--;
1da177e4	263	/* No more references to this file. Let go of it. */
68a2d76c	264	if (list_empty(&file->f_blocks) && !file->f_locks
1da177e4	265	&& !file->f_shares && !file->f_count) {
07ba8063	266	hlist_del(&file->f_list);
1da177e4 LT	267	nlmsvc_ops->fclose(file->f_file);
1da177e4 LT	268	kfree(file);
1da177e4 LT	269	}
	270	}
	271	}
353ab6e9	272	mutex_unlock(&nlm_file_mutex);
01df9c5e	273	return ret;
1da177e4 LT	274	}
	275
	276	/*
	277	* Release file. If there are no more remote locks on this file,
	278	* close it and free the handle.
	279	*
	280	* Note that we can't do proper reference counting without major
	281	* contortions because the code in fs/locks.c creates, deletes and
	282	* splits locks without notification. Our only way is to walk the
	283	* entire lock list each time we remove a lock.
	284	*/
	285	void
	286	nlm_release_file(struct nlm_file *file)
	287	{
	288	dprintk("lockd: nlm_release_file(%p, ct = %d)\n",
	289	file, file->f_count);
	290
	291	/* Lock file table */
353ab6e9	292	mutex_lock(&nlm_file_mutex);
1da177e4 LT	293
1da177e4 LT	294	/* If there are no more locks etc, delete the file */
f2af793d OK	295	if (--file->f_count == 0 && !nlm_file_inuse(file))
f2af793d OK	296	nlm_delete_file(file);
1da177e4	297
353ab6e9	298	mutex_unlock(&nlm_file_mutex);
1da177e4 LT	299	}
1da177e4 LT	300
f2af793d OK	301	/*
	302	* Helpers function for resource traversal
	303	*
	304	* nlmsvc_mark_host:
	305	* used by the garbage collector; simply sets h_inuse.
	306	* Always returns 0.
	307	*
	308	* nlmsvc_same_host:
	309	* returns 1 iff the two hosts match. Used to release
	310	* all resources bound to a specific host.
	311	*
	312	* nlmsvc_is_client:
	313	* returns 1 iff the host is a client.
	314	* Used by nlmsvc_invalidate_all
	315	*/
	316	static int
4373ea84	317	nlmsvc_mark_host(void data, struct nlm_host dummy)
f2af793d	318	{
4373ea84 WC	319	struct nlm_host *host = data;
4373ea84 WC	320
f2af793d OK	321	host->h_inuse = 1;
	322	return 0;
	323	}
	324
	325	static int
4373ea84	326	nlmsvc_same_host(void data, struct nlm_host other)
f2af793d	327	{
4373ea84 WC	328	struct nlm_host *host = data;
4373ea84 WC	329
f2af793d OK	330	return host == other;
	331	}
	332
	333	static int
4373ea84	334	nlmsvc_is_client(void data, struct nlm_host dummy)
f2af793d	335	{
4373ea84 WC	336	struct nlm_host *host = data;
4373ea84 WC	337
4481d103 N	338	if (host->h_server) {
	339	/* we are destroying locks even though the client
	340	* hasn't asked us too, so don't unmonitor the
	341	* client
	342	*/
	343	if (host->h_nsmhandle)
	344	host->h_nsmhandle->sm_sticky = 1;
	345	return 1;
	346	} else
	347	return 0;
f2af793d OK	348	}
f2af793d OK	349
1da177e4 LT	350	/*
	351	* Mark all hosts that still hold resources
	352	*/
	353	void
	354	nlmsvc_mark_resources(void)
	355	{
	356	dprintk("lockd: nlmsvc_mark_resources\n");
17efa372	357	nlm_traverse_files(NULL, nlmsvc_mark_host, NULL);
1da177e4 LT	358	}
	359
	360	/*
	361	* Release all resources held by the given client
	362	*/
	363	void
	364	nlmsvc_free_host_resources(struct nlm_host *host)
	365	{
	366	dprintk("lockd: nlmsvc_free_host_resources\n");
	367
17efa372	368	if (nlm_traverse_files(host, nlmsvc_same_host, NULL)) {
1da177e4	369	printk(KERN_WARNING
f0737a39	370	"lockd: couldn't remove all locks held by %s\n",
1da177e4	371	host->h_name);
f0737a39 OK	372	BUG();
f0737a39 OK	373	}
1da177e4 LT	374	}
1da177e4 LT	375
367c8c7b CL	376	/**
	377	* nlmsvc_invalidate_all - remove all locks held for clients
	378	*
	379	* Release all locks held by NFS clients.
	380	*
1da177e4 LT	381	*/
	382	void
	383	nlmsvc_invalidate_all(void)
	384	{
367c8c7b	385	/*
f2af793d OK	386	* Previously, the code would call
	387	* nlmsvc_free_host_resources for each client in
	388	* turn, which is about as inefficient as it gets.
	389	* Now we just do it once in nlm_traverse_files.
	390	*/
17efa372 WC	391	nlm_traverse_files(NULL, nlmsvc_is_client, NULL);
	392	}
	393
	394	static int
	395	nlmsvc_match_sb(void datap, struct nlm_file file)
	396	{
	397	struct super_block *sb = datap;
	398
	399	return sb == file->f_file->f_path.mnt->mnt_sb;
	400	}
	401
367c8c7b CL	402	/**
	403	* nlmsvc_unlock_all_by_sb - release locks held on this file system
	404	* @sb: super block
	405	*
	406	* Release all locks held by clients accessing this file system.
	407	*/
17efa372 WC	408	int
	409	nlmsvc_unlock_all_by_sb(struct super_block *sb)
	410	{
	411	int ret;
	412
	413	ret = nlm_traverse_files(sb, nlmsvc_always_match, nlmsvc_match_sb);
	414	return ret ? -EIO : 0;
1da177e4	415	}
17efa372	416	EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_sb);
4373ea84 WC	417
	418	static int
	419	nlmsvc_match_ip(void datap, struct nlm_host host)
	420	{
4516fc04	421	return rpc_cmp_addr(nlm_srcaddr(host), datap);
4373ea84 WC	422	}
4373ea84 WC	423
367c8c7b CL	424	/**
	425	* nlmsvc_unlock_all_by_ip - release local locks by IP address
	426	* @server_addr: server's IP address as seen by clients
	427	*
	428	* Release all locks held by clients accessing this host
	429	* via the passed in IP address.
	430	*/
4373ea84	431	int
367c8c7b	432	nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr)
4373ea84 WC	433	{
4373ea84 WC	434	int ret;
4373ea84	435
367c8c7b CL	436	ret = nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL);
367c8c7b CL	437	return ret ? -EIO : 0;
4373ea84 WC	438	}
4373ea84 WC	439	EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_ip);