On 2019/1/14 下午5:55, gregkh@linuxfoundation.org wrote:

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

My bad, the Fixes: tag is wrong.

It's should be 05a37c48604c ("btrfs: volumes: Make sure no dev extent is beyond device boundary"), which is not included in v4.19 stable.

Sorry for the inconvenience, Qu

------------------ original commit in Linus's tree ------------------

From 1b3922a8bc74231f9a767d1be6d9a061a4d4eeab Mon Sep 17 00:00:00 2001 From: Qu Wenruo wqu@suse.com Date: Tue, 8 Jan 2019 14:08:18 +0800 Subject: [PATCH] btrfs: Use real device structure to verify dev extent

[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.

Fixes: cf90d884b347 ("btrfs: Introduce mount time chunk <-> dev extent mapping check") CC: stable@vger.kernel.org # 4.19+ Reported-by: Filipe Manana fdmanana@suse.com Signed-off-by: Qu Wenruo wqu@suse.com Signed-off-by: David Sterba dsterba@suse.com

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;
  

• }
  

• }
• 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",