[linux-2.6-block.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		5
#define FILE_NRHASH		(1<<FILE_HASH_BITS)
static struct nlm_file *	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 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);

	for (file = nlm_files[hash]; file; file = file->f_next)
		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));
	file->f_hash = hash;
	init_MUTEX(&file->f_sema);

	/* 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 (nfserr %d)\n", ntohl(nfserr));
		goto out_free;
	}

	file->f_next = nlm_files[hash];
	nlm_files[hash] = file;

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)
{
	struct nlm_file	**fp, *f;

	nlm_debug_print_file("closing file", file);

	fp = nlm_files + file->f_hash;
	while ((f = *fp) != NULL) {
		if (f == file) {
			*fp = file->f_next;
			nlmsvc_ops->fclose(file->f_file);
			kfree(file);
			return;
		}
		fp = &f->f_next;
	}

	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, int action)
{
	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 (action == NLM_ACT_MARK)
			lockhost->h_inuse = 1;
		else if (action == NLM_ACT_CHECK)
			return 1;
		else if (action == NLM_ACT_UNLOCK) {
			struct file_lock lock = *fl;

			if (host && lockhost != host)
				continue;

			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;
}

/*
 * Operate on a single file
 */
static inline int
nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, int action)
{
	if (action == NLM_ACT_CHECK) {
		/* Fast path for mark and sweep garbage collection */
		if (file->f_count || file->f_blocks || file->f_shares)
			return 1;
	} else {
		nlmsvc_traverse_blocks(host, file, action);
		nlmsvc_traverse_shares(host, file, action);
	}
	return nlm_traverse_locks(host, file, action);
}

/*
 * Loop over all files in the file table.
 */
static int
nlm_traverse_files(struct nlm_host *host, int action)
{
	struct nlm_file	*file, **fp;
	int i, ret = 0;

	mutex_lock(&nlm_file_mutex);
	for (i = 0; i < FILE_NRHASH; i++) {
		fp = nlm_files + i;
		while ((file = *fp) != NULL) {
			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, action))
				ret = 1;

			mutex_lock(&nlm_file_mutex);
			file->f_count--;
			/* No more references to this file. Let go of it. */
			if (!file->f_blocks && !file->f_locks
			 && !file->f_shares && !file->f_count) {
				*fp = file->f_next;
				nlmsvc_ops->fclose(file->f_file);
				kfree(file);
			} else {
				fp = &file->f_next;
			}
		}
	}
	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) {
		if(!nlm_inspect_file(NULL, file, NLM_ACT_CHECK))
			nlm_delete_file(file);
	}

	mutex_unlock(&nlm_file_mutex);
}

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

	nlm_traverse_files(NULL, NLM_ACT_MARK);
}

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

/*
 * delete all hosts structs for clients
 */
void
nlmsvc_invalidate_all(void)
{
	struct nlm_host *host;
	while ((host = nlm_find_client()) != NULL) {
		nlmsvc_free_host_resources(host);
		host->h_expires = 0;
		host->h_killed = 1;
		nlm_release_host(host);
	}
}
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	*/
	28	#define FILE_HASH_BITS 5
	29	#define FILE_NRHASH (1<<FILE_HASH_BITS)
	30	static struct nlm_file * 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	{
	85	struct nlm_file *file;
	86	unsigned int hash;
	87	u32 nfserr;
1da177e4	88
0bbacc40	89	nlm_debug_print_fh("nlm_file_lookup", f);
1da177e4 LT	90
	91	hash = file_hash(f);
	92
	93	/* Lock file table */
353ab6e9	94	mutex_lock(&nlm_file_mutex);
1da177e4 LT	95
	96	for (file = nlm_files[hash]; file; file = file->f_next)
	97	if (!nfs_compare_fh(&file->f_handle, f))
	98	goto found;
	99
0bbacc40	100	nlm_debug_print_fh("creating file for", f);
1da177e4 LT	101
1da177e4 LT	102	nfserr = nlm_lck_denied_nolocks;
f8314dc6	103	file = kzalloc(sizeof(*file), GFP_KERNEL);
1da177e4 LT	104	if (!file)
	105	goto out_unlock;
	106
1da177e4 LT	107	memcpy(&file->f_handle, f, sizeof(struct nfs_fh));
	108	file->f_hash = hash;
	109	init_MUTEX(&file->f_sema);
	110
	111	/* Open the file. Note that this must not sleep for too long, else
	112	* we would lock up lockd:-) So no NFS re-exports, folks.
	113	*
	114	* We have to make sure we have the right credential to open
	115	* the file.
	116	*/
	117	if ((nfserr = nlmsvc_ops->fopen(rqstp, f, &file->f_file)) != 0) {
	118	dprintk("lockd: open failed (nfserr %d)\n", ntohl(nfserr));
	119	goto out_free;
	120	}
	121
	122	file->f_next = nlm_files[hash];
	123	nlm_files[hash] = file;
	124
	125	found:
	126	dprintk("lockd: found file %p (count %d)\n", file, file->f_count);
	127	*result = file;
	128	file->f_count++;
	129	nfserr = 0;
	130
	131	out_unlock:
353ab6e9	132	mutex_unlock(&nlm_file_mutex);
1da177e4 LT	133	return nfserr;
	134
	135	out_free:
	136	kfree(file);
	137	#ifdef CONFIG_LOCKD_V4
	138	if (nfserr == 1)
	139	nfserr = nlm4_stale_fh;
	140	else
	141	#endif
	142	nfserr = nlm_lck_denied;
	143	goto out_unlock;
	144	}
	145
	146	/*
	147	* Delete a file after having released all locks, blocks and shares
	148	*/
	149	static inline void
	150	nlm_delete_file(struct nlm_file *file)
	151	{
1da177e4 LT	152	struct nlm_file *fp, f;
1da177e4 LT	153
0bbacc40 CL	154	nlm_debug_print_file("closing file", file);
0bbacc40 CL	155
1da177e4 LT	156	fp = nlm_files + file->f_hash;
	157	while ((f = *fp) != NULL) {
	158	if (f == file) {
	159	*fp = file->f_next;
	160	nlmsvc_ops->fclose(file->f_file);
	161	kfree(file);
	162	return;
	163	}
	164	fp = &f->f_next;
	165	}
	166
	167	printk(KERN_WARNING "lockd: attempt to release unknown file!\n");
	168	}
	169
	170	/*
	171	* Loop over all locks on the given file and perform the specified
	172	* action.
	173	*/
	174	static int
	175	nlm_traverse_locks(struct nlm_host host, struct nlm_file file, int action)
	176	{
	177	struct inode *inode = nlmsvc_file_inode(file);
	178	struct file_lock *fl;
	179	struct nlm_host *lockhost;
	180
	181	again:
	182	file->f_locks = 0;
	183	for (fl = inode->i_flock; fl; fl = fl->fl_next) {
7117bf3d	184	if (fl->fl_lmops != &nlmsvc_lock_operations)
1da177e4 LT	185	continue;
	186
	187	/* update current lock count */
	188	file->f_locks++;
	189	lockhost = (struct nlm_host *) fl->fl_owner;
	190	if (action == NLM_ACT_MARK)
	191	lockhost->h_inuse = 1;
	192	else if (action == NLM_ACT_CHECK)
	193	return 1;
	194	else if (action == NLM_ACT_UNLOCK) {
	195	struct file_lock lock = *fl;
	196
	197	if (host && lockhost != host)
	198	continue;
	199
	200	lock.fl_type = F_UNLCK;
	201	lock.fl_start = 0;
	202	lock.fl_end = OFFSET_MAX;
	203	if (posix_lock_file(file->f_file, &lock) < 0) {
	204	printk("lockd: unlock failure in %s:%d\n",
	205	__FILE__, __LINE__);
	206	return 1;
	207	}
	208	goto again;
	209	}
	210	}
	211
	212	return 0;
	213	}
	214
	215	/*
	216	* Operate on a single file
	217	*/
	218	static inline int
	219	nlm_inspect_file(struct nlm_host host, struct nlm_file file, int action)
	220	{
	221	if (action == NLM_ACT_CHECK) {
	222	/* Fast path for mark and sweep garbage collection */
	223	if (file->f_count \|\| file->f_blocks \|\| file->f_shares)
	224	return 1;
	225	} else {
f3ee439f	226	nlmsvc_traverse_blocks(host, file, action);
5f12191b	227	nlmsvc_traverse_shares(host, file, action);
1da177e4 LT	228	}
	229	return nlm_traverse_locks(host, file, action);
	230	}
	231
	232	/*
	233	* Loop over all files in the file table.
	234	*/
	235	static int
	236	nlm_traverse_files(struct nlm_host *host, int action)
	237	{
	238	struct nlm_file file, *fp;
01df9c5e	239	int i, ret = 0;
1da177e4	240
353ab6e9	241	mutex_lock(&nlm_file_mutex);
1da177e4 LT	242	for (i = 0; i < FILE_NRHASH; i++) {
	243	fp = nlm_files + i;
	244	while ((file = *fp) != NULL) {
01df9c5e TM	245	file->f_count++;
	246	mutex_unlock(&nlm_file_mutex);
	247
1da177e4 LT	248	/* Traverse locks, blocks and shares of this file
1da177e4 LT	249	* and update file->f_locks count */
01df9c5e TM	250	if (nlm_inspect_file(host, file, action))
01df9c5e TM	251	ret = 1;
1da177e4	252
01df9c5e TM	253	mutex_lock(&nlm_file_mutex);
01df9c5e TM	254	file->f_count--;
1da177e4 LT	255	/* No more references to this file. Let go of it. */
	256	if (!file->f_blocks && !file->f_locks
	257	&& !file->f_shares && !file->f_count) {
	258	*fp = file->f_next;
	259	nlmsvc_ops->fclose(file->f_file);
	260	kfree(file);
	261	} else {
	262	fp = &file->f_next;
	263	}
	264	}
	265	}
353ab6e9	266	mutex_unlock(&nlm_file_mutex);
01df9c5e	267	return ret;
1da177e4 LT	268	}
	269
	270	/*
	271	* Release file. If there are no more remote locks on this file,
	272	* close it and free the handle.
	273	*
	274	* Note that we can't do proper reference counting without major
	275	* contortions because the code in fs/locks.c creates, deletes and
	276	* splits locks without notification. Our only way is to walk the
	277	* entire lock list each time we remove a lock.
	278	*/
	279	void
	280	nlm_release_file(struct nlm_file *file)
	281	{
	282	dprintk("lockd: nlm_release_file(%p, ct = %d)\n",
	283	file, file->f_count);
	284
	285	/* Lock file table */
353ab6e9	286	mutex_lock(&nlm_file_mutex);
1da177e4 LT	287
	288	/* If there are no more locks etc, delete the file */
	289	if(--file->f_count == 0) {
	290	if(!nlm_inspect_file(NULL, file, NLM_ACT_CHECK))
	291	nlm_delete_file(file);
	292	}
	293
353ab6e9	294	mutex_unlock(&nlm_file_mutex);
1da177e4 LT	295	}
	296
	297	/*
	298	* Mark all hosts that still hold resources
	299	*/
	300	void
	301	nlmsvc_mark_resources(void)
	302	{
	303	dprintk("lockd: nlmsvc_mark_resources\n");
	304
	305	nlm_traverse_files(NULL, NLM_ACT_MARK);
	306	}
	307
	308	/*
	309	* Release all resources held by the given client
	310	*/
	311	void
	312	nlmsvc_free_host_resources(struct nlm_host *host)
	313	{
	314	dprintk("lockd: nlmsvc_free_host_resources\n");
	315
	316	if (nlm_traverse_files(host, NLM_ACT_UNLOCK))
	317	printk(KERN_WARNING
	318	"lockd: couldn't remove all locks held by %s",
	319	host->h_name);
	320	}
	321
	322	/*
	323	* delete all hosts structs for clients
	324	*/
	325	void
	326	nlmsvc_invalidate_all(void)
	327	{
	328	struct nlm_host *host;
	329	while ((host = nlm_find_client()) != NULL) {
	330	nlmsvc_free_host_resources(host);
	331	host->h_expires = 0;
	332	host->h_killed = 1;
	333	nlm_release_host(host);
	334	}
	335	}