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> --- diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c index a687f385..da8c5986 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 +2836,12 @@ validate: * and drop the blocks. */ if (cfg->dblocks % cfg->agsize != 0 && + cfg->agcount > 1 && (cfg->dblocks % cfg->agsize < XFS_AG_MIN_BLOCKS(cfg->blocklog))) { +printf("%d %d %d\n", cfg->dblocks, cfg->agsize, cfg->dblocks % cfg->agsize); 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,