[mirror_ubuntu-zesty-kernel.git] / fs / cifs / cache.c

/*
 *   fs/cifs/cache.c - CIFS filesystem cache index structure definitions
 *
 *   Copyright (c) 2010 Novell, Inc.
 *   Authors(s): Suresh Jayaraman (sjayaraman@suse.de>
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
#include "fscache.h"
#include "cifs_debug.h"

/*
 * CIFS filesystem definition for FS-Cache
 */
struct fscache_netfs cifs_fscache_netfs = {
	.name = "cifs",
	.version = 0,
};

/*
 * Register CIFS for caching with FS-Cache
 */
int cifs_fscache_register(void)
{
	return fscache_register_netfs(&cifs_fscache_netfs);
}

/*
 * Unregister CIFS for caching
 */
void cifs_fscache_unregister(void)
{
	fscache_unregister_netfs(&cifs_fscache_netfs);
}

/*
 * Key layout of CIFS server cache index object
 */
struct cifs_server_key {
	uint16_t	family;		/* address family */
	__be16		port;		/* IP port */
	union {
		struct in_addr	ipv4_addr;
		struct in6_addr	ipv6_addr;
	} addr[0];
};

/*
 * Server object keyed by {IPaddress,port,family} tuple
 */
static uint16_t cifs_server_get_key(const void *cookie_netfs_data,
				   void *buffer, uint16_t maxbuf)
{
	const struct TCP_Server_Info *server = cookie_netfs_data;
	const struct sockaddr *sa = (struct sockaddr *) &server->dstaddr;
	const struct sockaddr_in *addr = (struct sockaddr_in *) sa;
	const struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *) sa;
	struct cifs_server_key *key = buffer;
	uint16_t key_len = sizeof(struct cifs_server_key);

	memset(key, 0, key_len);

	/*
	 * Should not be a problem as sin_family/sin6_family overlays
	 * sa_family field
	 */
	switch (sa->sa_family) {
	case AF_INET:
		key->family = sa->sa_family;
		key->port = addr->sin_port;
		key->addr[0].ipv4_addr = addr->sin_addr;
		key_len += sizeof(key->addr[0].ipv4_addr);
		break;

	case AF_INET6:
		key->family = sa->sa_family;
		key->port = addr6->sin6_port;
		key->addr[0].ipv6_addr = addr6->sin6_addr;
		key_len += sizeof(key->addr[0].ipv6_addr);
		break;

	default:
		cifs_dbg(VFS, "Unknown network family '%d'\n", sa->sa_family);
		key_len = 0;
		break;
	}

	return key_len;
}

/*
 * Server object for FS-Cache
 */
const struct fscache_cookie_def cifs_fscache_server_index_def = {
	.name = "CIFS.server",
	.type = FSCACHE_COOKIE_TYPE_INDEX,
	.get_key = cifs_server_get_key,
};

/*
 * Auxiliary data attached to CIFS superblock within the cache
 */
struct cifs_fscache_super_auxdata {
	u64	resource_id;		/* unique server resource id */
};

static char *extract_sharename(const char *treename)
{
	const char *src;
	char *delim, *dst;
	int len;

	/* skip double chars at the beginning */
	src = treename + 2;

	/* share name is always preceded by '\\' now */
	delim = strchr(src, '\\');
	if (!delim)
		return ERR_PTR(-EINVAL);
	delim++;
	len = strlen(delim);

	/* caller has to free the memory */
	dst = kstrndup(delim, len, GFP_KERNEL);
	if (!dst)
		return ERR_PTR(-ENOMEM);

	return dst;
}

/*
 * Superblock object currently keyed by share name
 */
static uint16_t cifs_super_get_key(const void *cookie_netfs_data, void *buffer,
				   uint16_t maxbuf)
{
	const struct cifs_tcon *tcon = cookie_netfs_data;
	char *sharename;
	uint16_t len;

	sharename = extract_sharename(tcon->treeName);
	if (IS_ERR(sharename)) {
		cifs_dbg(FYI, "%s: couldn't extract sharename\n", __func__);
		sharename = NULL;
		return 0;
	}

	len = strlen(sharename);
	if (len > maxbuf)
		return 0;

	memcpy(buffer, sharename, len);

	kfree(sharename);

	return len;
}

static uint16_t
cifs_fscache_super_get_aux(const void *cookie_netfs_data, void *buffer,
			   uint16_t maxbuf)
{
	struct cifs_fscache_super_auxdata auxdata;
	const struct cifs_tcon *tcon = cookie_netfs_data;

	memset(&auxdata, 0, sizeof(auxdata));
	auxdata.resource_id = tcon->resource_id;

	if (maxbuf > sizeof(auxdata))
		maxbuf = sizeof(auxdata);

	memcpy(buffer, &auxdata, maxbuf);

	return maxbuf;
}

static enum
fscache_checkaux cifs_fscache_super_check_aux(void *cookie_netfs_data,
					      const void *data,
					      uint16_t datalen)
{
	struct cifs_fscache_super_auxdata auxdata;
	const struct cifs_tcon *tcon = cookie_netfs_data;

	if (datalen != sizeof(auxdata))
		return FSCACHE_CHECKAUX_OBSOLETE;

	memset(&auxdata, 0, sizeof(auxdata));
	auxdata.resource_id = tcon->resource_id;

	if (memcmp(data, &auxdata, datalen) != 0)
		return FSCACHE_CHECKAUX_OBSOLETE;

	return FSCACHE_CHECKAUX_OKAY;
}

/*
 * Superblock object for FS-Cache
 */
const struct fscache_cookie_def cifs_fscache_super_index_def = {
	.name = "CIFS.super",
	.type = FSCACHE_COOKIE_TYPE_INDEX,
	.get_key = cifs_super_get_key,
	.get_aux = cifs_fscache_super_get_aux,
	.check_aux = cifs_fscache_super_check_aux,
};

/*
 * Auxiliary data attached to CIFS inode within the cache
 */
struct cifs_fscache_inode_auxdata {
	struct timespec	last_write_time;
	struct timespec	last_change_time;
	u64		eof;
};

static uint16_t cifs_fscache_inode_get_key(const void *cookie_netfs_data,
					   void *buffer, uint16_t maxbuf)
{
	const struct cifsInodeInfo *cifsi = cookie_netfs_data;
	uint16_t keylen;

	/* use the UniqueId as the key */
	keylen = sizeof(cifsi->uniqueid);
	if (keylen > maxbuf)
		keylen = 0;
	else
		memcpy(buffer, &cifsi->uniqueid, keylen);

	return keylen;
}

static void
cifs_fscache_inode_get_attr(const void *cookie_netfs_data, uint64_t *size)
{
	const struct cifsInodeInfo *cifsi = cookie_netfs_data;

	*size = cifsi->vfs_inode.i_size;
}

static uint16_t
cifs_fscache_inode_get_aux(const void *cookie_netfs_data, void *buffer,
			   uint16_t maxbuf)
{
	struct cifs_fscache_inode_auxdata auxdata;
	const struct cifsInodeInfo *cifsi = cookie_netfs_data;

	memset(&auxdata, 0, sizeof(auxdata));
	auxdata.eof = cifsi->server_eof;
	auxdata.last_write_time = cifsi->vfs_inode.i_mtime;
	auxdata.last_change_time = cifsi->vfs_inode.i_ctime;

	if (maxbuf > sizeof(auxdata))
		maxbuf = sizeof(auxdata);

	memcpy(buffer, &auxdata, maxbuf);

	return maxbuf;
}

static enum
fscache_checkaux cifs_fscache_inode_check_aux(void *cookie_netfs_data,
					      const void *data,
					      uint16_t datalen)
{
	struct cifs_fscache_inode_auxdata auxdata;
	struct cifsInodeInfo *cifsi = cookie_netfs_data;

	if (datalen != sizeof(auxdata))
		return FSCACHE_CHECKAUX_OBSOLETE;

	memset(&auxdata, 0, sizeof(auxdata));
	auxdata.eof = cifsi->server_eof;
	auxdata.last_write_time = cifsi->vfs_inode.i_mtime;
	auxdata.last_change_time = cifsi->vfs_inode.i_ctime;

	if (memcmp(data, &auxdata, datalen) != 0)
		return FSCACHE_CHECKAUX_OBSOLETE;

	return FSCACHE_CHECKAUX_OKAY;
}

static void cifs_fscache_inode_now_uncached(void *cookie_netfs_data)
{
	struct cifsInodeInfo *cifsi = cookie_netfs_data;
	struct pagevec pvec;
	pgoff_t first;
	int loop, nr_pages;

	pagevec_init(&pvec, 0);
	first = 0;

	cifs_dbg(FYI, "%s: cifs inode 0x%p now uncached\n", __func__, cifsi);

	for (;;) {
		nr_pages = pagevec_lookup(&pvec,
					  cifsi->vfs_inode.i_mapping, first,
					  PAGEVEC_SIZE - pagevec_count(&pvec));
		if (!nr_pages)
			break;

		for (loop = 0; loop < nr_pages; loop++)
			ClearPageFsCache(pvec.pages[loop]);

		first = pvec.pages[nr_pages - 1]->index + 1;

		pvec.nr = nr_pages;
		pagevec_release(&pvec);
		cond_resched();
	}
}

const struct fscache_cookie_def cifs_fscache_inode_object_def = {
	.name		= "CIFS.uniqueid",
	.type		= FSCACHE_COOKIE_TYPE_DATAFILE,
	.get_key	= cifs_fscache_inode_get_key,
	.get_attr	= cifs_fscache_inode_get_attr,
	.get_aux	= cifs_fscache_inode_get_aux,
	.check_aux	= cifs_fscache_inode_check_aux,
	.now_uncached	= cifs_fscache_inode_now_uncached,
};
Commit	Line	Data
f579cf3c SJ	1	/*
	2	* fs/cifs/cache.c - CIFS filesystem cache index structure definitions
	3	*
	4	* Copyright (c) 2010 Novell, Inc.
	5	* Authors(s): Suresh Jayaraman (sjayaraman@suse.de>
	6	*
	7	* This library is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU Lesser General Public License as published
	9	* by the Free Software Foundation; either version 2.1 of the License, or
	10	* (at your option) any later version.
	11	*
	12	* This library is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
	15	* the GNU Lesser General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU Lesser General Public License
	18	* along with this library; if not, write to the Free Software
	19	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	20	*/
	21	#include "fscache.h"
488f1d2d	22	#include "cifs_debug.h"
f579cf3c SJ	23
	24	/*
	25	* CIFS filesystem definition for FS-Cache
	26	*/
	27	struct fscache_netfs cifs_fscache_netfs = {
	28	.name = "cifs",
	29	.version = 0,
	30	};
	31
	32	/*
	33	* Register CIFS for caching with FS-Cache
	34	*/
	35	int cifs_fscache_register(void)
	36	{
	37	return fscache_register_netfs(&cifs_fscache_netfs);
	38	}
	39
	40	/*
	41	* Unregister CIFS for caching
	42	*/
	43	void cifs_fscache_unregister(void)
	44	{
	45	fscache_unregister_netfs(&cifs_fscache_netfs);
	46	}
	47
488f1d2d SJ	48	/*
	49	* Key layout of CIFS server cache index object
	50	*/
	51	struct cifs_server_key {
	52	uint16_t family; /* address family */
5443d130	53	__be16 port; /* IP port */
488f1d2d SJ	54	union {
	55	struct in_addr ipv4_addr;
	56	struct in6_addr ipv6_addr;
	57	} addr[0];
	58	};
	59
	60	/*
	61	* Server object keyed by {IPaddress,port,family} tuple
	62	*/
	63	static uint16_t cifs_server_get_key(const void *cookie_netfs_data,
	64	void *buffer, uint16_t maxbuf)
	65	{
	66	const struct TCP_Server_Info *server = cookie_netfs_data;
a9f1b85e PS	67	const struct sockaddr sa = (struct sockaddr ) &server->dstaddr;
	68	const struct sockaddr_in addr = (struct sockaddr_in ) sa;
	69	const struct sockaddr_in6 addr6 = (struct sockaddr_in6 ) sa;
488f1d2d SJ	70	struct cifs_server_key *key = buffer;
	71	uint16_t key_len = sizeof(struct cifs_server_key);
	72
	73	memset(key, 0, key_len);
	74
	75	/*
	76	* Should not be a problem as sin_family/sin6_family overlays
	77	* sa_family field
	78	*/
	79	switch (sa->sa_family) {
	80	case AF_INET:
a9f1b85e PS	81	key->family = sa->sa_family;
	82	key->port = addr->sin_port;
	83	key->addr[0].ipv4_addr = addr->sin_addr;
488f1d2d SJ	84	key_len += sizeof(key->addr[0].ipv4_addr);
	85	break;
	86
	87	case AF_INET6:
a9f1b85e PS	88	key->family = sa->sa_family;
	89	key->port = addr6->sin6_port;
	90	key->addr[0].ipv6_addr = addr6->sin6_addr;
488f1d2d SJ	91	key_len += sizeof(key->addr[0].ipv6_addr);
	92	break;
	93
	94	default:
f96637be	95	cifs_dbg(VFS, "Unknown network family '%d'\n", sa->sa_family);
488f1d2d SJ	96	key_len = 0;
	97	break;
	98	}
	99
	100	return key_len;
	101	}
	102
	103	/*
	104	* Server object for FS-Cache
	105	*/
	106	const struct fscache_cookie_def cifs_fscache_server_index_def = {
	107	.name = "CIFS.server",
	108	.type = FSCACHE_COOKIE_TYPE_INDEX,
	109	.get_key = cifs_server_get_key,
	110	};
d03382ce SJ	111
	112	/*
	113	* Auxiliary data attached to CIFS superblock within the cache
	114	*/
	115	struct cifs_fscache_super_auxdata {
	116	u64 resource_id; /* unique server resource id */
	117	};
	118
	119	static char extract_sharename(const char treename)
	120	{
	121	const char *src;
	122	char delim, dst;
	123	int len;
	124
	125	/* skip double chars at the beginning */
	126	src = treename + 2;
	127
	128	/* share name is always preceded by '\\' now */
	129	delim = strchr(src, '\\');
	130	if (!delim)
	131	return ERR_PTR(-EINVAL);
	132	delim++;
	133	len = strlen(delim);
	134
	135	/* caller has to free the memory */
	136	dst = kstrndup(delim, len, GFP_KERNEL);
	137	if (!dst)
	138	return ERR_PTR(-ENOMEM);
	139
	140	return dst;
	141	}
	142
	143	/*
	144	* Superblock object currently keyed by share name
	145	*/
	146	static uint16_t cifs_super_get_key(const void cookie_netfs_data, void buffer,
	147	uint16_t maxbuf)
	148	{
96daf2b0	149	const struct cifs_tcon *tcon = cookie_netfs_data;
d03382ce SJ	150	char *sharename;
	151	uint16_t len;
	152
	153	sharename = extract_sharename(tcon->treeName);
	154	if (IS_ERR(sharename)) {
f96637be	155	cifs_dbg(FYI, "%s: couldn't extract sharename\n", __func__);
d03382ce SJ	156	sharename = NULL;
	157	return 0;
	158	}
	159
	160	len = strlen(sharename);
	161	if (len > maxbuf)
	162	return 0;
	163
	164	memcpy(buffer, sharename, len);
	165
	166	kfree(sharename);
	167
	168	return len;
	169	}
	170
	171	static uint16_t
	172	cifs_fscache_super_get_aux(const void cookie_netfs_data, void buffer,
	173	uint16_t maxbuf)
	174	{
	175	struct cifs_fscache_super_auxdata auxdata;
96daf2b0	176	const struct cifs_tcon *tcon = cookie_netfs_data;
d03382ce SJ	177
	178	memset(&auxdata, 0, sizeof(auxdata));
	179	auxdata.resource_id = tcon->resource_id;
	180
	181	if (maxbuf > sizeof(auxdata))
	182	maxbuf = sizeof(auxdata);
	183
	184	memcpy(buffer, &auxdata, maxbuf);
	185
	186	return maxbuf;
	187	}
	188
	189	static enum
	190	fscache_checkaux cifs_fscache_super_check_aux(void *cookie_netfs_data,
	191	const void *data,
	192	uint16_t datalen)
	193	{
	194	struct cifs_fscache_super_auxdata auxdata;
96daf2b0	195	const struct cifs_tcon *tcon = cookie_netfs_data;
d03382ce SJ	196
	197	if (datalen != sizeof(auxdata))
	198	return FSCACHE_CHECKAUX_OBSOLETE;
	199
	200	memset(&auxdata, 0, sizeof(auxdata));
	201	auxdata.resource_id = tcon->resource_id;
	202
	203	if (memcmp(data, &auxdata, datalen) != 0)
	204	return FSCACHE_CHECKAUX_OBSOLETE;
	205
	206	return FSCACHE_CHECKAUX_OKAY;
	207	}
	208
	209	/*
	210	* Superblock object for FS-Cache
	211	*/
	212	const struct fscache_cookie_def cifs_fscache_super_index_def = {
	213	.name = "CIFS.super",
	214	.type = FSCACHE_COOKIE_TYPE_INDEX,
	215	.get_key = cifs_super_get_key,
	216	.get_aux = cifs_fscache_super_get_aux,
	217	.check_aux = cifs_fscache_super_check_aux,
	218	};
	219
9451a9a5 SJ	220	/*
	221	* Auxiliary data attached to CIFS inode within the cache
	222	*/
	223	struct cifs_fscache_inode_auxdata {
	224	struct timespec last_write_time;
	225	struct timespec last_change_time;
	226	u64 eof;
	227	};
	228
	229	static uint16_t cifs_fscache_inode_get_key(const void *cookie_netfs_data,
	230	void *buffer, uint16_t maxbuf)
	231	{
	232	const struct cifsInodeInfo *cifsi = cookie_netfs_data;
	233	uint16_t keylen;
	234
	235	/* use the UniqueId as the key */
	236	keylen = sizeof(cifsi->uniqueid);
	237	if (keylen > maxbuf)
	238	keylen = 0;
	239	else
	240	memcpy(buffer, &cifsi->uniqueid, keylen);
	241
	242	return keylen;
	243	}
	244
	245	static void
	246	cifs_fscache_inode_get_attr(const void cookie_netfs_data, uint64_t size)
	247	{
	248	const struct cifsInodeInfo *cifsi = cookie_netfs_data;
	249
	250	*size = cifsi->vfs_inode.i_size;
	251	}
	252
	253	static uint16_t
	254	cifs_fscache_inode_get_aux(const void cookie_netfs_data, void buffer,
	255	uint16_t maxbuf)
	256	{
	257	struct cifs_fscache_inode_auxdata auxdata;
	258	const struct cifsInodeInfo *cifsi = cookie_netfs_data;
	259
	260	memset(&auxdata, 0, sizeof(auxdata));
	261	auxdata.eof = cifsi->server_eof;
	262	auxdata.last_write_time = cifsi->vfs_inode.i_mtime;
	263	auxdata.last_change_time = cifsi->vfs_inode.i_ctime;
	264
	265	if (maxbuf > sizeof(auxdata))
	266	maxbuf = sizeof(auxdata);
	267
	268	memcpy(buffer, &auxdata, maxbuf);
	269
	270	return maxbuf;
	271	}
	272
	273	static enum
	274	fscache_checkaux cifs_fscache_inode_check_aux(void *cookie_netfs_data,
	275	const void *data,
	276	uint16_t datalen)
	277	{
	278	struct cifs_fscache_inode_auxdata auxdata;
	279	struct cifsInodeInfo *cifsi = cookie_netfs_data;
	280
	281	if (datalen != sizeof(auxdata))
	282	return FSCACHE_CHECKAUX_OBSOLETE;
	283
284	memset(&auxdata, 0, sizeof(auxdata));
285	auxdata.eof = cifsi->server_eof;
286	auxdata.last_write_time = cifsi->vfs_inode.i_mtime;
287	auxdata.last_change_time = cifsi->vfs_inode.i_ctime;
288
289	if (memcmp(data, &auxdata, datalen) != 0)
290	return FSCACHE_CHECKAUX_OBSOLETE;
291
292	return FSCACHE_CHECKAUX_OKAY;
293	}
294
85f2d6b4 SJ	295	static void cifs_fscache_inode_now_uncached(void *cookie_netfs_data)
	296	{
	297	struct cifsInodeInfo *cifsi = cookie_netfs_data;
	298	struct pagevec pvec;
	299	pgoff_t first;
	300	int loop, nr_pages;
	301
	302	pagevec_init(&pvec, 0);
	303	first = 0;
	304
f96637be	305	cifs_dbg(FYI, "%s: cifs inode 0x%p now uncached\n", __func__, cifsi);
85f2d6b4 SJ	306
	307	for (;;) {
	308	nr_pages = pagevec_lookup(&pvec,
	309	cifsi->vfs_inode.i_mapping, first,
	310	PAGEVEC_SIZE - pagevec_count(&pvec));
	311	if (!nr_pages)
	312	break;
	313
	314	for (loop = 0; loop < nr_pages; loop++)
	315	ClearPageFsCache(pvec.pages[loop]);
	316
	317	first = pvec.pages[nr_pages - 1]->index + 1;
	318
	319	pvec.nr = nr_pages;
	320	pagevec_release(&pvec);
	321	cond_resched();
	322	}
	323	}
	324
9451a9a5 SJ	325	const struct fscache_cookie_def cifs_fscache_inode_object_def = {
	326	.name = "CIFS.uniqueid",
	327	.type = FSCACHE_COOKIE_TYPE_DATAFILE,
	328	.get_key = cifs_fscache_inode_get_key,
	329	.get_attr = cifs_fscache_inode_get_attr,
	330	.get_aux = cifs_fscache_inode_get_aux,
	331	.check_aux = cifs_fscache_inode_check_aux,
85f2d6b4	332	.now_uncached = cifs_fscache_inode_now_uncached,
9451a9a5	333	};