smb: client: fix shared DFS root mounts with different prefixes
When having two DFS root mounts that are connected to same namespace,
same mount options but different prefix paths, we can't really use the
shared @server->origin_fullpath when chasing DFS links in them.
Move the origin_fullpath field to cifs_tcon structure so when having
shared DFS root mounts with different prefix paths, and we need to
chase any DFS links, dfs_get_automount_devname() will pick up the
correct full path out of the @tcon that will be used for the new
mount.
Before patch
mount.cifs //dom/dfs/dir /mnt/1 -o ...
mount.cifs //dom/dfs /mnt/2 -o ...
# shared server, ses, tcon
# server: origin_fullpath=//dom/dfs/dir
# @server->origin_fullpath + '/dir/link1'
$ ls /mnt/2/dir/link1
ls: cannot open directory '/mnt/2/dir/link1': No such file or directory
After patch
mount.cifs //dom/dfs/dir /mnt/1 -o ...
mount.cifs //dom/dfs /mnt/2 -o ...
# shared server & ses
# tcon_1: origin_fullpath=//dom/dfs/dir
# tcon_2: origin_fullpath=//dom/dfs
# @tcon_2->origin_fullpath + '/dir/link1'
$ ls /mnt/2/dir/link1
dir0 dir1 dir10 dir3 dir5 dir6 dir7 dir9 target2_file.txt tsub
Fixes: 8e3554150d6c ("cifs: fix sharing of DFS connections")
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
diff --git a/fs/smb/client/cifs_debug.c b/fs/smb/client/cifs_debug.c
index bfa8950..fb4162a 100644
--- a/fs/smb/client/cifs_debug.c
+++ b/fs/smb/client/cifs_debug.c
@@ -122,6 +122,12 @@ static void cifs_debug_tcon(struct seq_file *m, struct cifs_tcon *tcon)
seq_puts(m, " nosparse");
if (tcon->need_reconnect)
seq_puts(m, "\tDISCONNECTED ");
+ spin_lock(&tcon->tc_lock);
+ if (tcon->origin_fullpath) {
+ seq_printf(m, "\n\tDFS origin fullpath: %s",
+ tcon->origin_fullpath);
+ }
+ spin_unlock(&tcon->tc_lock);
seq_putc(m, '\n');
}
@@ -428,13 +434,9 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v)
seq_printf(m, "\nIn Send: %d In MaxReq Wait: %d",
atomic_read(&server->in_send),
atomic_read(&server->num_waiters));
- if (IS_ENABLED(CONFIG_CIFS_DFS_UPCALL)) {
- if (server->origin_fullpath)
- seq_printf(m, "\nDFS origin full path: %s",
- server->origin_fullpath);
- if (server->leaf_fullpath)
- seq_printf(m, "\nDFS leaf full path: %s",
- server->leaf_fullpath);
+ if (server->leaf_fullpath) {
+ seq_printf(m, "\nDFS leaf full path: %s",
+ server->leaf_fullpath);
}
seq_printf(m, "\n\n\tSessions: ");
