[people/ms/linux.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/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/lockd/sm_inter.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_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.
 */
u32
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;
	u32		nfserr;

	nlm_debug_print_fh("nlm_file_lookup", 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);
#ifdef CONFIG_LOCKD_V4
	if (nfserr == 1)
		nfserr = nlm4_stale_fh;
	else
#endif
	nfserr = nlm_lck_denied;
	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 (posix_lock_file(file->f_file, &lock) < 0) {
				printk("lockd: unlock failure in %s:%d\n",
						__FILE__, __LINE__);
				return 1;
			}
			goto again;
		}
	}

	return 0;
}

/*
 * 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(struct nlm_host *host, nlm_host_match_fn_t match)
{
	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) {
			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(host, 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(struct nlm_host *host, struct nlm_host *dummy)
{
	host->h_inuse = 1;
	return 0;
}

static int
nlmsvc_same_host(struct nlm_host *host, struct nlm_host *other)
{
	return host == other;
}

static int
nlmsvc_is_client(struct nlm_host *host, struct nlm_host *dummy)
{
	return host->h_server;
}

/*
 * 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);
}

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

/*
 * Remove all locks held for clients
 */
void
nlmsvc_invalidate_all(void)
{
	/* Release all locks held by NFS clients.
	 * 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);
}
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>
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	{
	46	struct inode *inode = file->f_file->f_dentry->d_inode;
	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	*/
	81	u32
	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;
	88	u32 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
1da177e4 LT	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);
	138	#ifdef CONFIG_LOCKD_V4
	139	if (nfserr == 1)
	140	nfserr = nlm4_stale_fh;
	141	else
	142	#endif
	143	nfserr = nlm_lck_denied;
	144	goto out_unlock;
	145	}
	146
	147	/*
	148	* Delete a file after having released all locks, blocks and shares
	149	*/
	150	static inline void
	151	nlm_delete_file(struct nlm_file *file)
	152	{
0bbacc40	153	nlm_debug_print_file("closing file", file);
07ba8063 OK	154	if (!hlist_unhashed(&file->f_list)) {
	155	hlist_del(&file->f_list);
	156	nlmsvc_ops->fclose(file->f_file);
	157	kfree(file);
	158	} else {
	159	printk(KERN_WARNING "lockd: attempt to release unknown file!\n");
1da177e4	160	}
1da177e4 LT	161	}
	162
	163	/*
	164	* Loop over all locks on the given file and perform the specified
	165	* action.
	166	*/
	167	static int
f2af793d OK	168	nlm_traverse_locks(struct nlm_host host, struct nlm_file file,
f2af793d OK	169	nlm_host_match_fn_t match)
1da177e4 LT	170	{
	171	struct inode *inode = nlmsvc_file_inode(file);
	172	struct file_lock *fl;
	173	struct nlm_host *lockhost;
	174
	175	again:
	176	file->f_locks = 0;
	177	for (fl = inode->i_flock; fl; fl = fl->fl_next) {
7117bf3d	178	if (fl->fl_lmops != &nlmsvc_lock_operations)
1da177e4 LT	179	continue;
	180
	181	/* update current lock count */
	182	file->f_locks++;
f2af793d	183
1da177e4	184	lockhost = (struct nlm_host *) fl->fl_owner;
f2af793d	185	if (match(lockhost, host)) {
1da177e4 LT	186	struct file_lock lock = *fl;
1da177e4 LT	187
1da177e4 LT	188	lock.fl_type = F_UNLCK;
	189	lock.fl_start = 0;
	190	lock.fl_end = OFFSET_MAX;
	191	if (posix_lock_file(file->f_file, &lock) < 0) {
	192	printk("lockd: unlock failure in %s:%d\n",
	193	__FILE__, __LINE__);
	194	return 1;
	195	}
	196	goto again;
	197	}
	198	}
	199
	200	return 0;
	201	}
	202
	203	/*
f2af793d OK	204	* Inspect a single file
	205	*/
	206	static inline int
	207	nlm_inspect_file(struct nlm_host host, struct nlm_file file, nlm_host_match_fn_t match)
	208	{
	209	nlmsvc_traverse_blocks(host, file, match);
	210	nlmsvc_traverse_shares(host, file, match);
	211	return nlm_traverse_locks(host, file, match);
	212	}
	213
	214	/*
	215	* Quick check whether there are still any locks, blocks or
	216	* shares on a given file.
1da177e4 LT	217	*/
1da177e4 LT	218	static inline int
f2af793d	219	nlm_file_inuse(struct nlm_file *file)
1da177e4	220	{
f2af793d OK	221	struct inode *inode = nlmsvc_file_inode(file);
	222	struct file_lock *fl;
	223
	224	if (file->f_count \|\| !list_empty(&file->f_blocks) \|\| file->f_shares)
	225	return 1;
	226
	227	for (fl = inode->i_flock; fl; fl = fl->fl_next) {
	228	if (fl->fl_lmops == &nlmsvc_lock_operations)
1da177e4	229	return 1;
1da177e4	230	}
f2af793d OK	231	file->f_locks = 0;
f2af793d OK	232	return 0;
1da177e4 LT	233	}
	234
	235	/*
	236	* Loop over all files in the file table.
	237	*/
	238	static int
f2af793d	239	nlm_traverse_files(struct nlm_host *host, nlm_host_match_fn_t match)
1da177e4	240	{
07ba8063 OK	241	struct hlist_node pos, next;
07ba8063 OK	242	struct nlm_file *file;
01df9c5e	243	int i, ret = 0;
1da177e4	244
353ab6e9	245	mutex_lock(&nlm_file_mutex);
1da177e4	246	for (i = 0; i < FILE_NRHASH; i++) {
07ba8063	247	hlist_for_each_entry_safe(file, pos, next, &nlm_files[i], f_list) {
01df9c5e TM	248	file->f_count++;
	249	mutex_unlock(&nlm_file_mutex);
	250
1da177e4 LT	251	/* Traverse locks, blocks and shares of this file
1da177e4 LT	252	* and update file->f_locks count */
f2af793d	253	if (nlm_inspect_file(host, file, match))
01df9c5e	254	ret = 1;
1da177e4	255
01df9c5e TM	256	mutex_lock(&nlm_file_mutex);
01df9c5e TM	257	file->f_count--;
1da177e4	258	/* No more references to this file. Let go of it. */
68a2d76c	259	if (list_empty(&file->f_blocks) && !file->f_locks
1da177e4	260	&& !file->f_shares && !file->f_count) {
07ba8063	261	hlist_del(&file->f_list);
1da177e4 LT	262	nlmsvc_ops->fclose(file->f_file);
1da177e4 LT	263	kfree(file);
1da177e4 LT	264	}
	265	}
	266	}
353ab6e9	267	mutex_unlock(&nlm_file_mutex);
01df9c5e	268	return ret;
1da177e4 LT	269	}
	270
	271	/*
	272	* Release file. If there are no more remote locks on this file,
	273	* close it and free the handle.
	274	*
	275	* Note that we can't do proper reference counting without major
	276	* contortions because the code in fs/locks.c creates, deletes and
	277	* splits locks without notification. Our only way is to walk the
	278	* entire lock list each time we remove a lock.
	279	*/
	280	void
	281	nlm_release_file(struct nlm_file *file)
	282	{
	283	dprintk("lockd: nlm_release_file(%p, ct = %d)\n",
	284	file, file->f_count);
	285
	286	/* Lock file table */
353ab6e9	287	mutex_lock(&nlm_file_mutex);
1da177e4 LT	288
1da177e4 LT	289	/* If there are no more locks etc, delete the file */
f2af793d OK	290	if (--file->f_count == 0 && !nlm_file_inuse(file))
f2af793d OK	291	nlm_delete_file(file);
1da177e4	292
353ab6e9	293	mutex_unlock(&nlm_file_mutex);
1da177e4 LT	294	}
1da177e4 LT	295
f2af793d OK	296	/*
	297	* Helpers function for resource traversal
	298	*
	299	* nlmsvc_mark_host:
	300	* used by the garbage collector; simply sets h_inuse.
	301	* Always returns 0.
	302	*
	303	* nlmsvc_same_host:
	304	* returns 1 iff the two hosts match. Used to release
	305	* all resources bound to a specific host.
	306	*
	307	* nlmsvc_is_client:
	308	* returns 1 iff the host is a client.
	309	* Used by nlmsvc_invalidate_all
	310	*/
	311	static int
	312	nlmsvc_mark_host(struct nlm_host host, struct nlm_host dummy)
	313	{
	314	host->h_inuse = 1;
	315	return 0;
	316	}
	317
	318	static int
	319	nlmsvc_same_host(struct nlm_host host, struct nlm_host other)
	320	{
	321	return host == other;
	322	}
	323
	324	static int
	325	nlmsvc_is_client(struct nlm_host host, struct nlm_host dummy)
	326	{
	327	return host->h_server;
	328	}
	329
1da177e4 LT	330	/*
	331	* Mark all hosts that still hold resources
	332	*/
	333	void
	334	nlmsvc_mark_resources(void)
	335	{
	336	dprintk("lockd: nlmsvc_mark_resources\n");
f2af793d	337	nlm_traverse_files(NULL, nlmsvc_mark_host);
1da177e4 LT	338	}
	339
	340	/*
	341	* Release all resources held by the given client
	342	*/
	343	void
	344	nlmsvc_free_host_resources(struct nlm_host *host)
	345	{
	346	dprintk("lockd: nlmsvc_free_host_resources\n");
	347
f2af793d	348	if (nlm_traverse_files(host, nlmsvc_same_host)) {
1da177e4	349	printk(KERN_WARNING
f0737a39	350	"lockd: couldn't remove all locks held by %s\n",
1da177e4	351	host->h_name);
f0737a39 OK	352	BUG();
f0737a39 OK	353	}
1da177e4 LT	354	}
	355
	356	/*
350fce8d	357	* Remove all locks held for clients
1da177e4 LT	358	*/
	359	void
	360	nlmsvc_invalidate_all(void)
	361	{
f2af793d OK	362	/* Release all locks held by NFS clients.
	363	* Previously, the code would call
	364	* nlmsvc_free_host_resources for each client in
	365	* turn, which is about as inefficient as it gets.
	366	* Now we just do it once in nlm_traverse_files.
	367	*/
	368	nlm_traverse_files(NULL, nlmsvc_is_client);
1da177e4	369	}