From 61cfea9bb84d41b09e59822c33b3eb27acc48358 Mon Sep 17 00:00:00 2001 From: WuBo Date: Tue, 26 Jul 2011 03:30:11 +0000 Subject: [PATCH] Btrfs: Protect the readonly flag of block group The access for ro in btrfs_block_group_cache should be protected because of the racy lock in relocation. Signed-off-by: Wu Bo Signed-off-by: Chris Mason --- fs/btrfs/extent-tree.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index db2057f..a4db88d 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -6549,8 +6549,6 @@ static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force) u64 min_allocable_bytes; int ret = -ENOSPC; - if (cache->ro) - return 0; /* * We need some metadata space and system metadata space for @@ -6566,6 +6564,12 @@ static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force) 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); @@ -6579,7 +6583,7 @@ static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force) cache->ro = 1; ret = 0; } - +out: spin_unlock(&cache->lock); spin_unlock(&sinfo->lock); return ret; -- 2.7.4