Compare prepaths when comparing superblocks

The patch
fs/cifs: make share unaccessible at root level mountable
makes use of prepaths when any component of the underlying path is
inaccessible.

When mounting 2 separate shares having different prepaths but are other
wise similar in other respects, we end up sharing superblocks when we
shouldn't be doing so.

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Tested-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
This commit is contained in:
Sachin Prabhu 2016-07-29 22:38:20 +01:00 committed by Steve French
parent 4214ebf465
commit c1d8b24d18
1 changed files with 20 additions and 1 deletions

View File

@ -2781,6 +2781,24 @@ compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
return 1;
}
static int
match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
{
struct cifs_sb_info *old = CIFS_SB(sb);
struct cifs_sb_info *new = mnt_data->cifs_sb;
if (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) {
if (!(new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH))
return 0;
/* The prepath should be null terminated strings */
if (strcmp(new->prepath, old->prepath))
return 0;
return 1;
}
return 0;
}
int
cifs_match_super(struct super_block *sb, void *data)
{
@ -2808,7 +2826,8 @@ cifs_match_super(struct super_block *sb, void *data)
if (!match_server(tcp_srv, volume_info) ||
!match_session(ses, volume_info) ||
!match_tcon(tcon, volume_info->UNC)) {
!match_tcon(tcon, volume_info->UNC) ||
!match_prepath(sb, mnt_data)) {
rc = 0;
goto out;
}