[patch added to 3.12-stable] Compare prepaths when comparing superblocks
From: Jiri Slaby <hidden>
Date: 2017-01-27 10:49:12
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
From: Sachin Prabhu <redacted> This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== commit c1d8b24d18192764fe82067ec6aa8d4c3bf094e0 upstream. 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 <redacted> Tested-by: Aurelien Aptel <redacted> Signed-off-by: Steve French <smfrench@gmail.com> Acked-by: Aurelien Aptel <redacted> Signed-off-by: Jiri Slaby <redacted> --- fs/cifs/connect.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 98c9c867f1b3..7491e8445458 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c@@ -2742,6 +2742,24 @@ 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) {
@@ -2769,7 +2787,8 @@ 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; }
--
2.11.0