Re: [PATCH URGENT v1.1 1/2] btrfs-progs: disk-io: Make super block write error easier to read

Nikolay Borisov
2019-03-27T11:34:16Z

On 27.03.19 г. 11:46 ч., Qu Wenruo wrote:
> When we failed to write super blocks, we just output something like:
> WARNING: failed to write sb: I/O error
> Or
> WARNING: failed to write all sb data
>
> There is no info about which device failed and there are two different
> error message for the same write error.
>
> This patch will change it to something more detailed:
> ERROR: failed to write super block for devid 1: write error: I/O error
>
> This provides the basis for later super block flush error handling.
>
> Signed-off-by: Qu Wenruo <wqu@suse.com>

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

> ---
> disk-io.c | 25 ++++++++++++++-----------
> 1 file changed, 14 insertions(+), 11 deletions(-)
>
> diff --git a/disk-io.c b/disk-io.c
> index 797b9b79ea3c..f7fb7026cd94 100644
> --- a/disk-io.c
> +++ b/disk-io.c
> @@ -1599,8 +1599,13 @@ static int write_dev_supers(struct btrfs_fs_info *fs_info,
> ret = pwrite64(device->fd, fs_info->super_copy,
> BTRFS_SUPER_INFO_SIZE,
> fs_info->super_bytenr);
> - if (ret != BTRFS_SUPER_INFO_SIZE)
> - goto write_err;
> + if (ret != BTRFS_SUPER_INFO_SIZE) {
> + errno = EIO;
> + error(
> + "failed to write super block for devid %llu: write error: %m",
> + device->devid);
> + return -EIO;
> + }
> return 0;
> }
>
> @@ -1622,18 +1627,16 @@ static int write_dev_supers(struct btrfs_fs_info *fs_info,
> */
> ret = pwrite64(device->fd, fs_info->super_copy,
> BTRFS_SUPER_INFO_SIZE, bytenr);
> - if (ret != BTRFS_SUPER_INFO_SIZE)
> - goto write_err;
> + if (ret != BTRFS_SUPER_INFO_SIZE) {
> + errno = EIO;
> + error(
> + "failed to write super block for devid %llu: write error: %m",
> + device->devid);
> + return -errno;
> + }
> }
>
> return 0;
> -
> -write_err:
> - if (ret > 0)
> - fprintf(stderr, "WARNING: failed to write all sb data\n");
> - else
> - fprintf(stderr, "WARNING: failed to write sb: %m\n");
> - return ret;
> }
>
> int write_all_supers(struct btrfs_fs_info *fs_info)
>