orangefs: free superblock when mount fails
authorMartin Brandenburg <martin@omnibond.com>
Fri, 14 Apr 2017 18:22:41 +0000 (14:22 -0400)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 15 Apr 2017 16:39:31 +0000 (09:39 -0700)
Otherwise lockdep says:

[ 1337.483798] ================================================
[ 1337.483999] [ BUG: lock held when returning to user space! ]
[ 1337.484252] 4.11.0-rc6 #19 Not tainted
[ 1337.484423] ------------------------------------------------
[ 1337.484626] mount/14766 is leaving the kernel with locks still held!
[ 1337.484841] 1 lock held by mount/14766:
[ 1337.485017]  #0:  (&type->s_umount_key#33/1){+.+.+.}, at: [<ffffffff8124171f>] sget_userns+0x2af/0x520

Caught by xfstests generic/413 which tried to mount with the unsupported
mount option dax.  Then xfstests generic/422 ran sync which deadlocks.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Acked-by: Mike Marshall <hubcap@omnibond.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/orangefs/devorangefs-req.c
fs/orangefs/orangefs-kernel.h
fs/orangefs/super.c

index c4ab6fdf17a01426db5d6e2bb9638130147bee61..e1534c9bab16ce69e30eefd6614ca2872595fb04 100644 (file)
@@ -208,14 +208,19 @@ restart:
                                continue;
                        /*
                         * Skip ops whose filesystem we don't know about unless
-                        * it is being mounted.
+                        * it is being mounted or unmounted.  It is possible for
+                        * a filesystem we don't know about to be unmounted if
+                        * it fails to mount in the kernel after userspace has
+                        * been sent the mount request.
                         */
                        /* XXX: is there a better way to detect this? */
                        } else if (ret == -1 &&
                                   !(op->upcall.type ==
                                        ORANGEFS_VFS_OP_FS_MOUNT ||
                                     op->upcall.type ==
-                                       ORANGEFS_VFS_OP_GETATTR)) {
+                                       ORANGEFS_VFS_OP_GETATTR ||
+                                    op->upcall.type ==
+                                       ORANGEFS_VFS_OP_FS_UMOUNT)) {
                                gossip_debug(GOSSIP_DEV_DEBUG,
                                    "orangefs: skipping op tag %llu %s\n",
                                    llu(op->tag), get_opname_string(op));
index 5e48a0be976194f466b654fc1aa11dc670cdd084..8afac46fcc87a1e1d3ea8c658e0ae60c336c3d5d 100644 (file)
@@ -249,6 +249,7 @@ struct orangefs_sb_info_s {
        char devname[ORANGEFS_MAX_SERVER_ADDR_LEN];
        struct super_block *sb;
        int mount_pending;
+       int no_list;
        struct list_head list;
 };
 
index cd261c8de53a1747fc2ca185d7b4c6f207f5521e..629d8c917fa679886715360fcfe8f6cee1b5a37f 100644 (file)
@@ -493,7 +493,7 @@ struct dentry *orangefs_mount(struct file_system_type *fst,
 
        if (ret) {
                d = ERR_PTR(ret);
-               goto free_op;
+               goto free_sb_and_op;
        }
 
        /*
@@ -519,6 +519,9 @@ struct dentry *orangefs_mount(struct file_system_type *fst,
        spin_unlock(&orangefs_superblocks_lock);
        op_release(new_op);
 
+       /* Must be removed from the list now. */
+       ORANGEFS_SB(sb)->no_list = 0;
+
        if (orangefs_userspace_version >= 20906) {
                new_op = op_alloc(ORANGEFS_VFS_OP_FEATURES);
                if (!new_op)
@@ -533,6 +536,10 @@ struct dentry *orangefs_mount(struct file_system_type *fst,
 
        return dget(sb->s_root);
 
+free_sb_and_op:
+       /* Will call orangefs_kill_sb with sb not in list. */
+       ORANGEFS_SB(sb)->no_list = 1;
+       deactivate_locked_super(sb);
 free_op:
        gossip_err("orangefs_mount: mount request failed with %d\n", ret);
        if (ret == -EINVAL) {
@@ -558,12 +565,14 @@ void orangefs_kill_sb(struct super_block *sb)
         */
         orangefs_unmount_sb(sb);
 
-       /* remove the sb from our list of orangefs specific sb's */
-
-       spin_lock(&orangefs_superblocks_lock);
-       __list_del_entry(&ORANGEFS_SB(sb)->list);       /* not list_del_init */
-       ORANGEFS_SB(sb)->list.prev = NULL;
-       spin_unlock(&orangefs_superblocks_lock);
+       if (!ORANGEFS_SB(sb)->no_list) {
+               /* remove the sb from our list of orangefs specific sb's */
+               spin_lock(&orangefs_superblocks_lock);
+               /* not list_del_init */
+               __list_del_entry(&ORANGEFS_SB(sb)->list);
+               ORANGEFS_SB(sb)->list.prev = NULL;
+               spin_unlock(&orangefs_superblocks_lock);
+       }
 
        /*
         * make sure that ORANGEFS_DEV_REMOUNT_ALL loop that might've seen us