On Tue, Jan 8, 2019 at 6:11 AM Qu Wenruo <w...@suse.com> wrote:
>
> [BUG]
> Linux v5.0-rc1 will fail fstests/btrfs/163 with the following kernel
> message:
>
> BTRFS error (device dm-6): dev extent devid 1 physical offset 13631488 len
> 8388608 is beyond device boundary 0
> BTRFS error (device dm-6): failed to verify dev extents against chunks: -117
> BTRFS error (device dm-6): open_ctree failed
>
> [CAUSE]
> Commit cf90d884b347 ("btrfs: Introduce mount time chunk <-> dev extent
> mapping check") introduced strict check on dev extents.
>
> We use btrfs_find_device() with dev uuid and fs uuid set to NULL, and
> only dependent on @devid to find the real device.
>
> For seed devices, we call clone_fs_devices() in open_seed_devices() to
> allow us search seed devices directly.
>
> However clone_fs_devices() just populates devices with devid and dev
> uuid, without populating other essential members, like disk_total_bytes.
>
> This makes any device returned by btrfs_find_device(fs_info, devid,
> NULL, NULL) is just a dummy, with 0 disk_total_bytes, and any dev
> extents on the seed device will not pass the device boundary check.
>
> [FIX]
> This patch will try to verify the device returned by btrfs_find_device()
> and if it's a dummy then re-search in seed devices.
>
> Reported-by: Filipe Manana <fdman...@suse.com>
> Fixes: cf90d884b347 ("btrfs: Introduce mount time chunk <-> dev extent
> mapping check")
> Signed-off-by: Qu Wenruo <w...@suse.com>
> ---
> fs/btrfs/volumes.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index 2576b1a379c9..3e4f8f88353e 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -7825,6 +7825,18 @@ static int verify_one_dev_extent(struct btrfs_fs_info
> *fs_info,
> ret = -EUCLEAN;
> goto out;
> }
> +
> + /* It's possible this device is a dummy for seed device */
> + if (dev->disk_total_bytes == 0) {
> + dev = find_device(fs_info->fs_devices->seed, devid, NULL);
> + if (!dev) {
> + btrfs_err(fs_info, "failed to find seed devid %llu",
> + devid);
> + ret = -EUCLEAN;
> + goto out;
> + }
> + }
Why just not pass the FSID (can be taken from fs_info->super_copy) to
the previous call to btrfs_find_device()?
It's a lot simpler.
> +
> if (physical_offset + physical_len > dev->disk_total_bytes) {
> btrfs_err(fs_info,
> "dev extent devid %llu physical offset %llu len %llu is beyond device
> boundary %llu",
> --
> 2.20.1
>
--
Filipe David Manana,
“Whether you think you can, or you think you can't — you're right.”
