From: Filipe Manana <fdmanana@suse.com>
Date: Thu, 4 Jul 2019 15:24:44 +0000 (+0100)
Subject: Btrfs: fix inode cache waiters hanging on path allocation failure
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=9d123a35d7e97bb2139747b16127c9b22b6a593e;p=openwrt%2Fstaging%2Fblogic.git

Btrfs: fix inode cache waiters hanging on path allocation failure

If the caching thread fails to allocate a path, it returns without waking
up any cache waiters, leaving them hang forever. Fix this by following the
same approach as when we fail to start the caching thread: print an error
message, disable inode caching and make the wakers fallback to non-caching
mode behaviour (calling btrfs_find_free_objectid()).

Fixes: 581bb050941b4f ("Btrfs: Cache free inode numbers in memory")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---

diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
index c242ae434355..c692c8b6e371 100644
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -42,8 +42,10 @@ static int caching_kthread(void *data)
 		return 0;
 
 	path = btrfs_alloc_path();
-	if (!path)
+	if (!path) {
+		fail_caching_thread(root);
 		return -ENOMEM;
+	}
 
 	/* Since the commit root is read-only, we can safely skip locking. */
 	path->skip_locking = 1;