During mount context, we aren't verifying the superblock checksum for all the devices, instead, we verify it only for the struct btrfs_fs_device::latest_bdev. This patch fixes it by moving the checksum verification code from the function open_ctree() into the function btrfs_read_dev_one_super().
By doing this now we are verifying the superblock checksum in the mount-context, device-replace and, device-delete context. The device-replace and device-delete call-chain is as show below after this patch. delete-device/replace: btrfs_rm_device() || btrfs_dev_replace_by_ioctl() |_btrfs_find_device_by_devspec() |_btrfs_find_device_missing_or_by_path() |_btrfs_find_device_by_path() |_btrfs_get_bdev_and_sb() |_btrfs_read_dev_super() |_btrfs_read_dev_one_super() |_btrfs_check_super_csum() Test case: Before: mkfs.btrfs -fq -draid1 -mraid1 /dev/sdb /dev/sdc dd if=/dev/urandom of=/dev/sdc ibs=1 obs=1 count=1 seek=64K mount /dev/sdb /btrfs <-- success as kernel does not check csum for non-btrfs_fs_devices::latest_bdev. After: mkfs.btrfs -fq -draid1 -mraid1 /dev/sdb /dev/sdc dd if=/dev/urandom of=/dev/sdc ibs=1 obs=1 count=1 seek=64K mount /dev/sdb /btrfs mount: mount /dev/sdc on /btrfs failed: Structure needs cleaning mount -o degraded /dev/sdc /btrfs mount: mount /dev/sdc on /btrfs failed: Structure needs cleaning So the current recovery step is to fix the primary superblock, by using the btrfs-progs cli. Signed-off-by: Anand Jain <anand.j...@oracle.com> Reviewed-by: Nikolay Borisov <nbori...@suse.com> --- v1->v2: git commit log update. With the call-chain (which I believe will go away in the long term, we need the uuid from the userland not the disk-path). And add test case. Check err < 0 explicitly and drop check for "else if (err == -EUCLEAN)" v1: err = btrfs_check_super_csum(bh->b_data); if (err) { if (err == -EINVAL) pr_err("BTRFS error (device %pg): unsupported checksum algorithm", bdev); else if (err == -EUCLEAN) pr_err("BTRFS error (device %pg): superblock checksum mismatch", bdev); brelse(bh); return err; } fs/btrfs/disk-io.c | 33 +++++++++++++++++---------------- 1 file changed, 17 insertions(+), 16 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 37b0cf489fdd..1eabcc4bf8d2 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2565,22 +2565,6 @@ int open_ctree(struct super_block *sb, } /* - * We want to check superblock checksum, the type is stored inside. - * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k). - */ - err = btrfs_check_super_csum(bh->b_data); - if (err) { - if (err == -EINVAL) - pr_err("BTRFS error (device %pg): unsupported checksum algorithm", - fs_devices->latest_bdev); - else if (err == -EUCLEAN) - pr_err("BTRFS error (device %pg): superblock checksum mismatch", - fs_devices->latest_bdev); - brelse(bh); - goto fail_alloc; - } - - /* * super_copy is zeroed at allocation time and we never touch the * following bytes up to INFO_SIZE, the checksum is calculated from * the whole block of INFO_SIZE @@ -3126,6 +3110,7 @@ int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num, struct buffer_head *bh; struct btrfs_super_block *super; u64 bytenr; + int err; bytenr = btrfs_sb_offset(copy_num); if (bytenr + BTRFS_SUPER_INFO_SIZE >= i_size_read(bdev->bd_inode)) @@ -3146,6 +3131,22 @@ int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num, return -EINVAL; } + /* + * Check the superblock checksum, the type is stored inside. + * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k). + */ + err = btrfs_check_super_csum(bh->b_data); + if (err < 0) { + if (err == -EINVAL) + pr_err("BTRFS error (device %pg): unsupported checksum algorithm", + bdev); + else if (err == -EUCLEAN) + pr_err("BTRFS error (device %pg): superblock checksum mismatch", + bdev); + brelse(bh); + return err; + } + *bh_ret = bh; return 0; } -- 2.7.0 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html