Btrfs: Use btrfs_join_transaction to avoid deadlocks during snapshot creation
Snapshot creation happens at a specific time during transaction commit. We
need to make sure the code called by snapshot creation doesn't wait
for the running transaction to commit.
This changes btrfs_delete_inode and finish_pending_snaps to use
btrfs_join_transaction instead of btrfs_start_transaction to avoid deadlocks.
It would be better if btrfs_delete_inode didn't use the join, but the
call path that triggers it is:
btrfs_commit_transaction->create_pending_snapshots->
create_pending_snapshot->btrfs_lookup_dentry->
fixup_tree_root_location->btrfs_read_fs_root->
btrfs_read_fs_root_no_name->btrfs_orphan_cleanup->iput
This will be fixed in a later patch by moving the orphan cleanup to the
cleaner thread.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2 files changed