diff mbox

[2/3,xenial,SRU] Compare prepaths when comparing superblocks

Message ID 1474633449-52911-3-git-send-email-seth.forshee@canonical.com
State New
Headers show

Commit Message

Seth Forshee Sept. 23, 2016, 12:24 p.m. UTC 
From: Sachin Prabhu <sprabhu@redhat.com>

BugLink: http://bugs.launchpad.net/bugs/1626112

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>
(cherry picked from commit c1d8b24d18192764fe82067ec6aa8d4c3bf094e0)
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
---
 fs/cifs/connect.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)
diff mbox

Patch

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 94e6982..b5c5aa6 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2812,6 +2812,24 @@  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)
 {
@@ -2839,7 +2857,8 @@  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;
 	}