From: Josef Bacik josef@toxicpanda.com
commit 18d3bff411c8d46d40537483bdc0b61b33ce0371 upstream.
This was partially fixed by f3e3d9cc3525 ("btrfs: avoid possible signal interruption of btrfs_drop_snapshot() on relocation tree"), however it missed a spot when we restart a trans handle because we need to end the transaction. The fix is the same, simply use btrfs_join_transaction() instead of btrfs_start_transaction() when deleting reloc roots.
Fixes: f3e3d9cc3525 ("btrfs: avoid possible signal interruption of btrfs_drop_snapshot() on relocation tree") CC: stable@vger.kernel.org # 5.4+ Signed-off-by: Josef Bacik josef@toxicpanda.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/btrfs/extent-tree.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
--- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -5390,7 +5390,15 @@ int btrfs_drop_snapshot(struct btrfs_roo goto out_free; }
- trans = btrfs_start_transaction(tree_root, 0); + /* + * Use join to avoid potential EINTR from transaction + * start. See wait_reserve_ticket and the whole + * reservation callchain. + */ + if (for_reloc) + trans = btrfs_join_transaction(tree_root); + else + trans = btrfs_start_transaction(tree_root, 0); if (IS_ERR(trans)) { err = PTR_ERR(trans); goto out_free;