This is a note to let you know that I've just added the patch titled Btrfs: don't allow the replace procedure on read only filesystems to the 3.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: btrfs-don-t-allow-the-replace-procedure-on-read-only-filesystems.patch and it can be found in the queue-3.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From bbb651e469d99f0088e286fdeb54acca7bb4ad4e Mon Sep 17 00:00:00 2001 From: Stefan Behrens <sbehrens@xxxxxxxxxxxxxxxx> Date: Mon, 19 Aug 2013 18:51:13 +0200 Subject: Btrfs: don't allow the replace procedure on read only filesystems From: Stefan Behrens <sbehrens@xxxxxxxxxxxxxxxx> commit bbb651e469d99f0088e286fdeb54acca7bb4ad4e upstream. If you start the replace procedure on a read only filesystem, at the end the procedure fails to write the updated dev_items to the chunk tree. The problem is that this error is not indicated except for a WARN_ON(). If the user now thinks that everything was done as expected and destroys the source device (with mkfs or with a hammer). The next mount fails with "failed to read chunk root" and the filesystem is gone. This commit adds code to fail the attempt to start the replace procedure if the filesystem is mounted read-only. Signed-off-by: Stefan Behrens <sbehrens@xxxxxxxxxxxxxxxx> Signed-off-by: Josef Bacik <jbacik@xxxxxxxxxxxx> Signed-off-by: Chris Mason <chris.mason@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/btrfs/ioctl.c | 3 +++ 1 file changed, 3 insertions(+) --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3299,6 +3299,9 @@ static long btrfs_ioctl_dev_replace(stru switch (p->cmd) { case BTRFS_IOCTL_DEV_REPLACE_CMD_START: + if (root->fs_info->sb->s_flags & MS_RDONLY) + return -EROFS; + if (atomic_xchg( &root->fs_info->mutually_exclusive_operation_running, 1)) { Patches currently in stable-queue which might be from sbehrens@xxxxxxxxxxxxxxxx are queue-3.10/btrfs-don-t-allow-the-replace-procedure-on-read-only-filesystems.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html