Re: [PATCH V4 18/20] xfsprogs: Add mkfs option to create filesystem with large extent counters

Darrick J. Wong
2022-01-05T01:15:46Z

On Tue, Dec 14, 2021 at 02:18:09PM +0530, Chandan Babu R wrote:
> Enabling nrext64 option on mkfs.xfs command line extends the maximum values of
> inode data and attr fork extent counters to 2^48 - 1 and 2^32 - 1
> respectively. This also sets the XFS_SB_FEAT_INCOMPAT_NREXT64 incompat flag
> on the superblock preventing older kernels from mounting such a filesystem.
>
> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>

Looks reasonable. There's a silly nit that mtk prefers that each
sentence in a Linux man page start on a separate line, but I'll let Eric
decide if he cares about that for xfsprogs manpages.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
> man/man8/mkfs.xfs.8 | 7 +++++++
> mkfs/xfs_mkfs.c | 23 +++++++++++++++++++++++
> 2 files changed, 30 insertions(+)
>
> diff --git a/man/man8/mkfs.xfs.8 b/man/man8/mkfs.xfs.8
> index a7f70285..923940e3 100644
> --- a/man/man8/mkfs.xfs.8
> +++ b/man/man8/mkfs.xfs.8
> @@ -639,6 +639,13 @@ space over time such that no free extents are large enough to
> accommodate a chunk of 64 inodes. Without this feature enabled, inode
> allocations can fail with out of space errors under severe fragmented
> free space conditions.
> +.TP
> +.BI nrext64[= value]
> +Extend maximum values of inode data and attr fork extent counters from 2^31 -
> +1 and 2^15 - 1 to 2^48 - 1 and 2^32 - 1 respectively. If the value is
> +omitted, 1 is assumed. This feature is disabled by default. This feature is
> +only available for filesystems formatted with -m crc=1.
> +.TP
> .RE
> .PP
> .PD 0
> diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
> index 53904677..6609776f 100644
> --- a/mkfs/xfs_mkfs.c
> +++ b/mkfs/xfs_mkfs.c
> @@ -78,6 +78,7 @@ enum {
> I_ATTR,
> I_PROJID32BIT,
> I_SPINODES,
> + I_NREXT64,
> I_MAX_OPTS,
> };
>
> @@ -432,6 +433,7 @@ static struct opt_params iopts = {
> [I_ATTR] = "attr",
> [I_PROJID32BIT] = "projid32bit",
> [I_SPINODES] = "sparse",
> + [I_NREXT64] = "nrext64",
> },
> .subopt_params = {
> { .index = I_ALIGN,
> @@ -480,6 +482,12 @@ static struct opt_params iopts = {
> .maxval = 1,
> .defaultval = 1,
> },
> + { .index = I_NREXT64,
> + .conflicts = { { NULL, LAST_CONFLICT } },
> + .minval = 0,
> + .maxval = 1,
> + .defaultval = 1,
> + }
> },
> };
>
> @@ -804,6 +812,7 @@ struct sb_feat_args {
> bool bigtime; /* XFS_SB_FEAT_INCOMPAT_BIGTIME */
> bool nodalign;
> bool nortalign;
> + bool nrext64;
> };
>
> struct cli_params {
> @@ -1585,6 +1594,9 @@ inode_opts_parser(
> case I_SPINODES:
> cli->sb_feat.spinodes = getnum(value, opts, subopt);
> break;
> + case I_NREXT64:
> + cli->sb_feat.nrext64 = getnum(value, opts, subopt);
> + break;
> default:
> return -EINVAL;
> }
> @@ -2153,6 +2165,14 @@ _("timestamps later than 2038 not supported without CRC support\n"));
> usage();
> }
> cli->sb_feat.bigtime = false;
> +
> + if (cli->sb_feat.nrext64 &&
> + cli_opt_set(&iopts, I_NREXT64)) {
> + fprintf(stderr,
> +_("64 bit extent count not supported without CRC support\n"));
> + usage();
> + }
> + cli->sb_feat.nrext64 = false;
> }
>
> if (!cli->sb_feat.finobt) {
> @@ -3145,6 +3165,8 @@ sb_set_features(
> sbp->sb_features_incompat |= XFS_SB_FEAT_INCOMPAT_SPINODES;
> }
>
> + if (fp->nrext64)
> + sbp->sb_features_incompat |= XFS_SB_FEAT_INCOMPAT_NREXT64;
> }
>
> /*
> @@ -3854,6 +3876,7 @@ main(
> .nodalign = false,
> .nortalign = false,
> .bigtime = false,
> + .nrext64 = false,
> },
> };
>
> --
> 2.30.2
>