Trying to reproduce a log enospc bug I hit a panic in the async reclaim code
during log replay. This is because we use fs_info->fs_root as our root for
shrinking and such. Technically we can use whatever root we want, but let's
just not allow async reclaim while we're doing log replay. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
---
fs/btrfs/extent-tree.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 53714ef..e3fde87 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4513,7 +4513,13 @@ again:
space_info->flush = 1;
} else if (!ret && space_info->flags &
BTRFS_BLOCK_GROUP_METADATA) {
used += orig_bytes;
- if (need_do_async_reclaim(space_info, root->fs_info, used) &&
+ /*
+ * We will do the space reservation dance during log replay,
+ * which means we won't have fs_info->fs_root set, so don't do
+ * the async reclaim as we will panic.
+ */
+ if (root->fs_info->fs_root &&
+ need_do_async_reclaim(space_info, root->fs_info, used) &&
!work_busy(&root->fs_info->async_reclaim_work))
queue_work(system_unbound_wq,
&root->fs_info->async_reclaim_work);
--
1.8.3.1
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