On 26.03.2018 11:27, Anand Jain wrote:
> 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.
Which call chain provides the device-replace and device-delete contexts?
I think it is worth it documenting them in the changelog.
>
> Signed-off-by: Anand Jain <anand.jain@xxxxxxxxxx>
Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>
> ---
> fs/btrfs/disk-io.c | 35 +++++++++++++++++------------------
> 1 file changed, 17 insertions(+), 18 deletions(-)
>
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 6299ab18da5f..3cc50041c0b9 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -2565,24 +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
> - 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
> @@ -3128,6 +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))
> @@ -3148,6 +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) {
> + 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;
> }
>
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