fs/cifs/cache.c - arm/linux - Git at Google

 /*
  *   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;
 }

 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,
 };
	/*
	* 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;
	}

	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,
	};