On Mon, Sep 14, 2020 at 02:00:52PM -0500, Eric Sandeen wrote:
> When a too-small device is created with stripe geometry, we hit an
> assert in align_ag_geometry():
>
> # truncate --size=10444800 testfile
> # mkfs.xfs -dsu=65536,sw=1 testfile
> mkfs.xfs: xfs_mkfs.c:2834: align_ag_geometry: Assertion `cfg->agcount != 0' failed.
>
> This is because align_ag_geometry() finds that the size of the last
> (only) AG is too small, and attempts to trim it off. Obviously 0
> AGs is invalid, and we hit the ASSERT.
>
> Fix this by skipping the last-ag-trim if there is only one AG, and
> add a new test to validate_ag_geometry() which offers a very specific,
> clear warning if the device (in dblocks) is smaller than the minimum
> allowed AG size.
>
> Reported-by: Zdenek Kabelac <zkabelac@xxxxxxxxxx>
> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
Seems fine to me,
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
> ---
>
> V2: remove stray printf, sorry
>
> diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
> index a687f385..2139aedb 100644
> --- a/mkfs/xfs_mkfs.c
> +++ b/mkfs/xfs_mkfs.c
> @@ -1038,6 +1038,15 @@ validate_ag_geometry(
> uint64_t agsize,
> uint64_t agcount)
> {
> + /* Is this device simply too small? */
> + if (dblocks < XFS_AG_MIN_BLOCKS(blocklog)) {
> + fprintf(stderr,
> + _("device (%lld blocks) too small, need at least %lld blocks\n"),
> + (long long)dblocks,
> + (long long)XFS_AG_MIN_BLOCKS(blocklog));
> + usage();
> + }
> +
> if (agsize < XFS_AG_MIN_BLOCKS(blocklog)) {
> fprintf(stderr,
> _("agsize (%lld blocks) too small, need at least %lld blocks\n"),
> @@ -2827,11 +2836,11 @@ validate:
> * and drop the blocks.
> */
> if (cfg->dblocks % cfg->agsize != 0 &&
> + cfg->agcount > 1 &&
> (cfg->dblocks % cfg->agsize < XFS_AG_MIN_BLOCKS(cfg->blocklog))) {
> ASSERT(!cli_opt_set(&dopts, D_AGCOUNT));
> cfg->dblocks = (xfs_rfsblock_t)((cfg->agcount - 1) * cfg->agsize);
> cfg->agcount--;
> - ASSERT(cfg->agcount != 0);
> }
>
> validate_ag_geometry(cfg->blocklog, cfg->dblocks,
>
>
