smb3: extend fscache mount volume coherency check

It is better to check volume id and creation time, not just
the root inode number to verify if the volume has changed
when remounting.

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/cifs/cache.c b/fs/cifs/cache.c
index b7420e605b28804be516a5cd9c2ab250bffc5ea0..0f2adecb94f22473c0e9af3952f5716fd5ef5624 100644 (file)
--- a/fs/cifs/cache.c
+++ b/fs/cifs/cache.c
@@ -53,13 +53,6 @@ const struct fscache_cookie_def cifs_fscache_server_index_def = {
        .type = FSCACHE_COOKIE_TYPE_INDEX,
 };
 
-/*
- * Auxiliary data attached to CIFS superblock within the cache
- */
-struct cifs_fscache_super_auxdata {
-       u64     resource_id;            /* unique server resource id */
-};
-
 char *extract_sharename(const char *treename)
 {
        const char *src;
@@ -98,6 +91,8 @@ fscache_checkaux cifs_fscache_super_check_aux(void *cookie_netfs_data,
 
        memset(&auxdata, 0, sizeof(auxdata));
        auxdata.resource_id = tcon->resource_id;
+       auxdata.vol_create_time = tcon->vol_create_time;
+       auxdata.vol_serial_number = tcon->vol_serial_number;
 
        if (memcmp(data, &auxdata, datalen) != 0)
                return FSCACHE_CHECKAUX_OBSOLETE;

diff --git a/fs/cifs/fscache.c b/fs/cifs/fscache.c
index ea6ace9c2417dd954047799e691a7759cd2c5471..da688185403c3ee2550590e37c7bc6ff82d50f99 100644 (file)
--- a/fs/cifs/fscache.c
+++ b/fs/cifs/fscache.c
@@ -96,6 +96,7 @@ void cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
 {
        struct TCP_Server_Info *server = tcon->ses->server;
        char *sharename;
+       struct cifs_fscache_super_auxdata auxdata;
 
        sharename = extract_sharename(tcon->treeName);
        if (IS_ERR(sharename)) {
@@ -104,11 +105,16 @@ void cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
                return;
        }
 
+       memset(&auxdata, 0, sizeof(auxdata));
+       auxdata.resource_id = tcon->resource_id;
+       auxdata.vol_create_time = tcon->vol_create_time;
+       auxdata.vol_serial_number = tcon->vol_serial_number;
+
        tcon->fscache =
                fscache_acquire_cookie(server->fscache,
                                       &cifs_fscache_super_index_def,
                                       sharename, strlen(sharename),
-                                      &tcon->resource_id, sizeof(tcon->resource_id),
+                                      &auxdata, sizeof(auxdata),
                                       tcon, 0, true);
        kfree(sharename);
        cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
@@ -117,8 +123,15 @@ void cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
 
 void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon)
 {
+       struct cifs_fscache_super_auxdata auxdata;
+
+       memset(&auxdata, 0, sizeof(auxdata));
+       auxdata.resource_id = tcon->resource_id;
+       auxdata.vol_create_time = tcon->vol_create_time;
+       auxdata.vol_serial_number = tcon->vol_serial_number;
+
        cifs_dbg(FYI, "%s: (0x%p)\n", __func__, tcon->fscache);
-       fscache_relinquish_cookie(tcon->fscache, &tcon->resource_id, false);
+       fscache_relinquish_cookie(tcon->fscache, &auxdata, false);
        tcon->fscache = NULL;
 }
 

diff --git a/fs/cifs/fscache.h b/fs/cifs/fscache.h
index 8c0862e413064c32a6df043e8d27f0d8530b2849..1091633d2adbd2aed356c653d052e96d4b4268ef 100644 (file)
--- a/fs/cifs/fscache.h
+++ b/fs/cifs/fscache.h
@@ -27,6 +27,15 @@
 
 #ifdef CONFIG_CIFS_FSCACHE
 
+/*
+ * Auxiliary data attached to CIFS superblock within the cache
+ */
+struct cifs_fscache_super_auxdata {
+       u64     resource_id;            /* unique server resource id */
+       __le64  vol_create_time;
+       u32     vol_serial_number;
+} __packed;
+
 /*
  * Auxiliary data attached to CIFS inode within the cache
  */