From: Filipe Manana Date: Mon, 11 Jun 2018 18:24:16 +0000 (+0100) Subject: Btrfs: fix return value on rename exchange failure X-Git-Tag: v4.18-rc3~1^2~3 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=c5b4a50b74018b3677098151ec5f4fce07d5e6a0;p=uclinux-h8%2Flinux.git Btrfs: fix return value on rename exchange failure If we failed during a rename exchange operation after starting/joining a transaction, we would end up replacing the return value, stored in the local 'ret' variable, with the return value from btrfs_end_transaction(). So this could end up returning 0 (success) to user space despite the operation having failed and aborted the transaction, because if there are multiple tasks having a reference on the transaction at the time btrfs_end_transaction() is called by the rename exchange, that function returns 0 (otherwise it returns -EIO and not the original error value). So fix this by not overwriting the return value on error after getting a transaction handle. Fixes: cdd1fedf8261 ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT") CC: stable@vger.kernel.org # 4.9+ Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba --- diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index c12b7a6e534a..a6bf9e2ff68f 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -9443,6 +9443,7 @@ static int btrfs_rename_exchange(struct inode *old_dir, u64 new_idx = 0; u64 root_objectid; int ret; + int ret2; bool root_log_pinned = false; bool dest_log_pinned = false; @@ -9639,7 +9640,8 @@ out_fail: dest_log_pinned = false; } } - ret = btrfs_end_transaction(trans); + ret2 = btrfs_end_transaction(trans); + ret = ret ? ret : ret2; out_notrans: if (new_ino == BTRFS_FIRST_FREE_OBJECTID) up_read(&fs_info->subvol_sem);