From: Josef Bacik Date: Tue, 19 Nov 2019 18:59:20 +0000 (-0500) Subject: btrfs: don't double lock the subvol_sem for rename exchange X-Git-Tag: v5.15~4704^2~24 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=943eb3bf25f4a7b745dd799e031be276aa104d82;p=platform%2Fkernel%2Flinux-starfive.git btrfs: don't double lock the subvol_sem for rename exchange If we're rename exchanging two subvols we'll try to lock this lock twice, which is bad. Just lock once if either of the ino's are subvols. Fixes: cdd1fedf8261 ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba --- diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 5766c2d..e3c7664 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -9554,9 +9554,8 @@ static int btrfs_rename_exchange(struct inode *old_dir, btrfs_init_log_ctx(&ctx_dest, new_inode); /* close the race window with snapshot create/destroy ioctl */ - if (old_ino == BTRFS_FIRST_FREE_OBJECTID) - down_read(&fs_info->subvol_sem); - if (new_ino == BTRFS_FIRST_FREE_OBJECTID) + if (old_ino == BTRFS_FIRST_FREE_OBJECTID || + new_ino == BTRFS_FIRST_FREE_OBJECTID) down_read(&fs_info->subvol_sem); /* @@ -9790,9 +9789,8 @@ out_fail: ret = ret ? ret : ret2; } out_notrans: - if (new_ino == BTRFS_FIRST_FREE_OBJECTID) - up_read(&fs_info->subvol_sem); - if (old_ino == BTRFS_FIRST_FREE_OBJECTID) + if (new_ino == BTRFS_FIRST_FREE_OBJECTID || + old_ino == BTRFS_FIRST_FREE_OBJECTID) up_read(&fs_info->subvol_sem); ASSERT(list_empty(&ctx_root.list));