From 9e271ae27e4407388c5b25c747abc25c07838b0b Mon Sep 17 00:00:00 2001 From: Anand Jain Date: Fri, 14 Aug 2015 18:33:02 +0800 Subject: [PATCH] Btrfs: kernel operation should come after user input has been verified By general rule of thumb there shouldn't be any way that user land could trigger a kernel operation just by sending wrong arguments. Here do commit cleanups after user input has been verified. Signed-off-by: Anand Jain Signed-off-by: David Sterba --- fs/btrfs/dev-replace.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index 7aed8a8ce694..02031fc07f7f 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -327,19 +327,6 @@ int btrfs_dev_replace_start(struct btrfs_root *root, args->start.tgtdev_name[0] == '\0') return -EINVAL; - /* - * Here we commit the transaction to make sure commit_total_bytes - * of all the devices are updated. - */ - trans = btrfs_attach_transaction(root); - if (!IS_ERR(trans)) { - ret = btrfs_commit_transaction(trans, root); - if (ret) - return ret; - } else if (PTR_ERR(trans) != -ENOENT) { - return PTR_ERR(trans); - } - /* the disk copy procedure reuses the scrub code */ mutex_lock(&fs_info->volume_mutex); ret = btrfs_dev_replace_find_srcdev(root, args->start.srcdevid, @@ -356,6 +343,19 @@ int btrfs_dev_replace_start(struct btrfs_root *root, if (ret) return ret; + /* + * Here we commit the transaction to make sure commit_total_bytes + * of all the devices are updated. + */ + trans = btrfs_attach_transaction(root); + if (!IS_ERR(trans)) { + ret = btrfs_commit_transaction(trans, root); + if (ret) + return ret; + } else if (PTR_ERR(trans) != -ENOENT) { + return PTR_ERR(trans); + } + btrfs_dev_replace_lock(dev_replace); switch (dev_replace->replace_state) { case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: