btrfs: qgroup: Fix a race in delayed_ref which leads to abort trans
Between btrfs_allocerved_file_extent() and
btrfs_add_delayed_qgroup_reserve(), there is a window that delayed_refs
are run and delayed ref head maybe freed before
btrfs_add_delayed_qgroup_reserve().
This will cause btrfs_dad_delayed_qgroup_reserve() to return -ENOENT,
and cause transaction to be aborted.
This patch will record qgroup reserve space info into delayed_ref_head
at btrfs_add_delayed_ref(), to eliminate the race window.
Reported-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 6f030c2..4439fbb 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2127,17 +2127,13 @@
ins.type = BTRFS_EXTENT_ITEM_KEY;
ret = btrfs_alloc_reserved_file_extent(trans, root,
root->root_key.objectid,
- btrfs_ino(inode), file_pos, &ins);
- if (ret < 0)
- goto out;
+ btrfs_ino(inode), file_pos,
+ ram_bytes, &ins);
/*
- * Release the reserved range from inode dirty range map, and
- * move it to delayed ref codes, as now accounting only happens at
- * commit_transaction() time.
+ * Release the reserved range from inode dirty range map, as it is
+ * already moved into delayed_ref_head
*/
btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
- ret = btrfs_add_delayed_qgroup_reserve(root->fs_info, trans,
- root->objectid, disk_bytenr, ram_bytes);
out:
btrfs_free_path(path);