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: Suresh Jayaraman <sjayaraman@xxxxxxx>
---
fs/cifs/cache.c | 109 +++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/cifs/cifsglob.h | 4 +
fs/cifs/connect.c | 3 +
fs/cifs/fscache.c | 17 ++++++++
fs/cifs/fscache.h | 6 ++
fs/cifs/inode.c | 3 +
6 files changed, 142 insertions(+)
Index: cifs-2.6/fs/cifs/cache.c
===================================================================
--- cifs-2.6.orig/fs/cifs/cache.c
+++ cifs-2.6/fs/cifs/cache.c
@@ -106,3 +106,112 @@ const struct fscache_cookie_def cifs_fsc
.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,
+};
+
Index: cifs-2.6/fs/cifs/fscache.c
===================================================================
--- cifs-2.6.orig/fs/cifs/fscache.c
+++ cifs-2.6/fs/cifs/fscache.c
@@ -39,3 +39,20 @@ void cifs_fscache_release_client_cookie(
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;
+}
Index: cifs-2.6/fs/cifs/fscache.h
===================================================================
--- cifs-2.6.orig/fs/cifs/fscache.h
+++ cifs-2.6/fs/cifs/fscache.h
@@ -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 */
Index: cifs-2.6/fs/cifs/cifsglob.h
===================================================================
--- cifs-2.6.orig/fs/cifs/cifsglob.h
+++ cifs-2.6/fs/cifs/cifsglob.h
@@ -314,6 +314,10 @@ 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)? */
};
Index: cifs-2.6/fs/cifs/connect.c
===================================================================
--- cifs-2.6.orig/fs/cifs/connect.c
+++ cifs-2.6/fs/cifs/connect.c
@@ -1779,6 +1779,7 @@ cifs_put_tcon(struct cifsTconInfo *tcon)
_FreeXid(xid);
tconInfoFree(tcon);
+ cifs_fscache_release_super_cookie(tcon);
cifs_put_smb_ses(ses);
}
@@ -1848,6 +1849,8 @@ cifs_get_tcon(struct cifsSesInfo *ses, s
list_add(&tcon->tcon_list, &ses->tcon_list);
write_unlock(&cifs_tcp_ses_lock);
+ cifs_fscache_get_super_cookie(tcon);
+
return tcon;
out_fail:
Index: cifs-2.6/fs/cifs/inode.c
===================================================================
--- cifs-2.6.orig/fs/cifs/inode.c
+++ cifs-2.6/fs/cifs/inode.c
@@ -807,6 +807,9 @@ struct inode *cifs_root_iget(struct supe
if (!inode)
return ERR_PTR(-ENOMEM);
+ /* populate tcon->resource_id */
+ cifs_sb->tcon->resource_id = CIFS_I(inode)->uniqueid;
+
if (rc && cifs_sb->tcon->ipc) {
cFYI(1, "ipc connection - fake read inode");
inode->i_mode |= S_IFDIR;
--
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