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 <wu.bo@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
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 @@
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 @@
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 @@
cache->ro = 1;
ret = 0;
}
-
+out:
spin_unlock(&cache->lock);
spin_unlock(&sinfo->lock);
return ret;