Btrfs: fix oops while writing data to SSD partitions
Here I have a two SSD-partitions btrfs, and they are defaultly set to
"data=raid0, metadata=raid1", then I try to fill my btrfs partition
till "No space left on device", via "dd if=/dev/zero of=/mnt/btrfs/tmp".
I get an oops panic from kernel BUG at fs/btrfs/extent-tree.c:5199!, which
refers to find_free_extent's
BUG_ON(index != get_block_group_index(block_group));
In SSD mode, in order to find enough space to alloc, we may check the
block_group cache which has been checked sometime before, but the index is not
updated, where it hits the BUG_ON.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Acked-by: Josef Bacik <josef@redhat.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 a4db88d..b172b7f 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5079,7 +5079,9 @@
* group is does point to and try again
*/
if (!last_ptr_loop && last_ptr->block_group &&
- last_ptr->block_group != block_group) {
+ last_ptr->block_group != block_group &&
+ index <=
+ get_block_group_index(last_ptr->block_group)) {
btrfs_put_block_group(block_group);
block_group = last_ptr->block_group;