Commit dde5abee authored Sep 16, 2010 by Josef Bacik Committed by Chris Mason Oct 29, 2010

Btrfs: check cache->caching_ctl before returning if caching has started



With the free space disk caching we can mark the block group as started with the
caching, but we don't have a caching ctl.  This can race with anybody else who
tries to get the caching ctl before we cache (this is very hard to do btw).  So
instead check to see if cache->caching_ctl is set, and if not return NULL.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>

parent 9d66e233

fs/btrfs/extent-tree.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -242,6 +242,12 @@ get_caching_control(struct btrfs_block_group_cache *cache)
		return NULL;
		}

		/* We're loading it the fast way, so we don't have a caching_ctl. */
		if (!cache->caching_ctl) {
		spin_unlock(&cache->lock);
		return NULL;
		}

		ctl = cache->caching_ctl;
		atomic_inc(&ctl->count);
		spin_unlock(&cache->lock);

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