On Tue, May 21, 2019 at 02:30:57PM -0500, Eric Sandeen wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> Data block sharing (a.k.a. reflink) has been stable for a while, so turn
> it on by default.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> [sandeen: update comments & man page]
> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
Looks good to me.
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Hmm I'm not allowed to RVB my own patch, right?
--D
> ---
>
> diff --git a/man/man8/mkfs.xfs.8 b/man/man8/mkfs.xfs.8
> index 4b8c78c..78b1501 100644
> --- a/man/man8/mkfs.xfs.8
> +++ b/man/man8/mkfs.xfs.8
> @@ -231,7 +231,7 @@ available for the data forks of regular files.
> .IP
> By default,
> .B mkfs.xfs
> -will not create reference count btrees and therefore will not enable the
> +will create reference count btrees and therefore will enable the
> reflink feature. This feature is only available for filesystems created with
> the (default)
> .B \-m crc=1
> @@ -239,6 +239,13 @@ option set. When the option
> .B \-m crc=0
> is used, the reference count btree feature is not supported and reflink is
> disabled.
> +.IP
> +Note: the filesystem DAX mount option (
> +.B \-o dax
> +) is incompatible with
> +reflink-enabled XFS filesystems. To use filesystem DAX with XFS, specify the
> +.B \-m reflink=0
> +option to mkfs.xfs to disable the reflink feature.
> .RE
> .TP
> .BI \-d " data_section_options"
> diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
> index 0910664..ddb25ec 100644
> --- a/mkfs/xfs_mkfs.c
> +++ b/mkfs/xfs_mkfs.c
> @@ -1973,15 +1973,15 @@ _("Directory ftype field always enabled on CRC enabled filesystems\n"));
> usage();
> }
>
> - } else {
> + } else { /* !crcs_enabled */
> /*
> - * The kernel doesn't currently support crc=0,finobt=1
> - * filesystems. If crcs are not enabled and the user has not
> - * explicitly turned finobt on, then silently turn it off to
> - * avoid an unnecessary warning.
> + * The kernel doesn't support crc=0,finobt=1 filesystems.
> + * If crcs are not enabled and the user has not explicitly
> + * turned finobt on, then silently turn it off to avoid an
> + * unnecessary warning.
> * If the user explicitly tried to use crc=0,finobt=1,
> * then issue an error.
> - * The same is also for sparse inodes.
> + * The same is also true for sparse inodes and reflink.
> */
> if (cli->sb_feat.finobt && cli_opt_set(&mopts, M_FINOBT)) {
> fprintf(stderr,
> @@ -2004,7 +2004,7 @@ _("rmapbt not supported without CRC support\n"));
> }
> cli->sb_feat.rmapbt = false;
>
> - if (cli->sb_feat.reflink) {
> + if (cli->sb_feat.reflink && cli_opt_set(&mopts, M_REFLINK)) {
> fprintf(stderr,
> _("reflink not supported without CRC support\n"));
> usage();
> @@ -3876,7 +3876,7 @@ main(
> .finobt = true,
> .spinodes = true,
> .rmapbt = false,
> - .reflink = false,
> + .reflink = true,
> .parent_pointers = false,
> .nodalign = false,
> .nortalign = false,
>
>
