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Commit d03382ce authored by Suresh Jayaraman's avatar Suresh Jayaraman Committed by Steve French
Browse files

cifs: define superblock-level cache index objects and register them 



Define superblock-level cache index objects (managed by cifsTconInfo structs).
Each superblock object is created in a server-level index object and in itself
an index into which inode-level objects are inserted.

The superblock object is keyed by sharename. The UniqueId/IndexNumber is used to
validate that the exported share is the same since we accessed it last time.

Signed-off-by: default avatarSuresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent 8913007e

fs/cifs/cache.c

+109 −0
Original line number Diff line number Diff line
@@ -106,3 +106,112 @@ const struct fscache_cookie_def cifs_fscache_server_index_def = { 
	.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 cifsTconInfo *tcon = cookie_netfs_data;

	char *sharename;

	uint16_t len;



	sharename = extract_sharename(tcon->treeName);

	if (IS_ERR(sharename)) {

		cFYI(1, "CIFS: couldn't extract sharename\n");

		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 cifsTconInfo *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 cifsTconInfo *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,

};

fs/cifs/cifsglob.h

+4 −0
Original line number Diff line number Diff line
@@ -299,6 +299,10 @@ struct cifsTconInfo { 
	bool local_lease:1; /* check leases (only) on local system not remote */

	bool broken_posix_open; /* e.g. Samba server versions < 3.3.2, 3.2.9 */

	bool need_reconnect:1; /* connection reset, tid now invalid */

#ifdef CONFIG_CIFS_FSCACHE

	u64 resource_id;		/* server resource id */

	struct fscache_cookie *fscache;	/* cookie for share */

#endif

	/* BB add field for back pointer to sb struct(s)? */

};

fs/cifs/connect.c

+3 −0
Original line number Diff line number Diff line
@@ -1837,6 +1837,7 @@ cifs_put_tcon(struct cifsTconInfo *tcon) 
	_FreeXid(xid);



	tconInfoFree(tcon);

	cifs_fscache_release_super_cookie(tcon);

	cifs_put_smb_ses(ses);

}
@@ -1906,6 +1907,8 @@ cifs_get_tcon(struct cifsSesInfo *ses, struct smb_vol *volume_info) 
	list_add(&tcon->tcon_list, &ses->tcon_list);

	write_unlock(&cifs_tcp_ses_lock);



	cifs_fscache_get_super_cookie(tcon);



	return tcon;



out_fail:

fs/cifs/fscache.c

+17 −0
Original line number Diff line number Diff line
@@ -39,3 +39,20 @@ void cifs_fscache_release_client_cookie(struct TCP_Server_Info *server) 
	server->fscache = NULL;

}



void cifs_fscache_get_super_cookie(struct cifsTconInfo *tcon)

{

	struct TCP_Server_Info *server = tcon->ses->server;



	tcon->fscache =

		fscache_acquire_cookie(server->fscache,

				&cifs_fscache_super_index_def, tcon);

	cFYI(1, "CIFS: get superblock cookie (0x%p/0x%p)",

				server->fscache, tcon->fscache);

}



void cifs_fscache_release_super_cookie(struct cifsTconInfo *tcon)

{

	cFYI(1, "CIFS: releasing superblock cookie (0x%p)", tcon->fscache);

	fscache_relinquish_cookie(tcon->fscache, 0);

	tcon->fscache = NULL;

}

fs/cifs/fscache.h

+6 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 


extern struct fscache_netfs cifs_fscache_netfs;

extern const struct fscache_cookie_def cifs_fscache_server_index_def;

extern const struct fscache_cookie_def cifs_fscache_super_index_def;



extern int cifs_fscache_register(void);

extern void cifs_fscache_unregister(void);
@@ -38,6 +39,8 @@ extern void cifs_fscache_unregister(void); 
 */

extern void cifs_fscache_get_client_cookie(struct TCP_Server_Info *);

extern void cifs_fscache_release_client_cookie(struct TCP_Server_Info *);

extern void cifs_fscache_get_super_cookie(struct cifsTconInfo *);

extern void cifs_fscache_release_super_cookie(struct cifsTconInfo *);



#else /* CONFIG_CIFS_FSCACHE */

static inline int cifs_fscache_register(void) { return 0; }
@@ -47,6 +50,9 @@ static inline void 
cifs_fscache_get_client_cookie(struct TCP_Server_Info *server) {}

static inline void

cifs_fscache_get_client_cookie(struct TCP_Server_Info *server); {}

static inline void cifs_fscache_get_super_cookie(struct cifsTconInfo *tcon) {}

static inline void

cifs_fscache_release_super_cookie(struct cifsTconInfo *tcon) {}



#endif /* CONFIG_CIFS_FSCACHE */