From mboxrd@z Thu Jan 1 00:00:00 1970 From: WuBo Subject: [PATCH] Btrfs: Protect the readonly flag of block group Date: Tue, 26 Jul 2011 11:30:11 +0800 Message-ID: <4E2E34C3.2040203@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: Linux Btrfs Return-path: List-ID: The access for ro in btrfs_block_group_cache should be protected because of the racy lock in relocation. Signed-off-by: Wu Bo --- fs/btrfs/extent-tree.c | 11 +++++++---- 1 files changed, 7 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 9ee6bd5..cc9bf80 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -8143,11 +8143,14 @@ static int set_block_group_ro(struct btrfs_block_group_cache *cache) u64 num_bytes; int ret = -ENOSPC; - if (cache->ro) - return 0; - spin_lock(&sinfo->lock); spin_lock(&cache->lock); + + if (cache->ro) { + ret = 0; + goto out; + } + num_bytes = cache->key.offset - cache->reserved - cache->pinned - cache->bytes_super - btrfs_block_group_used(&cache->item); @@ -8160,7 +8163,7 @@ static int set_block_group_ro(struct btrfs_block_group_cache *cache) cache->ro = 1; ret = 0; } - +out: spin_unlock(&cache->lock); spin_unlock(&sinfo->lock); return ret; -- 1.7.3.1