Re: [PATCH 39/43] xfs: support zone gaps

Darrick J. Wong
2024-12-13T22:55:14Z

On Wed, Dec 11, 2024 at 09:55:04AM +0100, Christoph Hellwig wrote:
> Zoned devices can have gaps beyond the usable capacity of a zone and the
> end in the LBA/daddr address space. In other words, the hardware
> equivalent to the RT groups already takes care of the power of 2
> alignment for us. In this case the sparse FSB/RTB address space maps 1:1
> to the device address space.

Heh, sparse lba ranges.

> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> fs/xfs/libxfs/xfs_format.h | 4 +++-
> fs/xfs/libxfs/xfs_group.h | 6 +++++-
> fs/xfs/libxfs/xfs_rtgroup.h | 13 ++++++++-----
> fs/xfs/libxfs/xfs_sb.c | 3 +++
> fs/xfs/libxfs/xfs_zones.c | 19 +++++++++++++++++--
> fs/xfs/xfs_mount.h | 9 +++++++++
> 6 files changed, 45 insertions(+), 9 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
> index fc56de8fe696..9491a09f6aa7 100644
> --- a/fs/xfs/libxfs/xfs_format.h
> +++ b/fs/xfs/libxfs/xfs_format.h
> @@ -398,6 +398,7 @@ xfs_sb_has_ro_compat_feature(
> #define XFS_SB_FEAT_INCOMPAT_PARENT (1 << 7) /* parent pointers */
> #define XFS_SB_FEAT_INCOMPAT_METADIR (1 << 8) /* metadata dir tree */
> #define XFS_SB_FEAT_INCOMPAT_ZONED (1U << 31)/* zoned RT allocator */
> +#define XFS_SB_FEAT_INCOMPAT_ZONE_GAPS (1U << 30)/* RTGs have LBA gaps */

These will have to be renumbered before merging.

Otherwise looks ok,
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> #define XFS_SB_FEAT_INCOMPAT_ALL \
> (XFS_SB_FEAT_INCOMPAT_FTYPE | \
> @@ -409,7 +410,8 @@ xfs_sb_has_ro_compat_feature(
> XFS_SB_FEAT_INCOMPAT_EXCHRANGE | \
> XFS_SB_FEAT_INCOMPAT_PARENT | \
> XFS_SB_FEAT_INCOMPAT_METADIR | \
> - XFS_SB_FEAT_INCOMPAT_ZONED)
> + XFS_SB_FEAT_INCOMPAT_ZONED | \
> + XFS_SB_FEAT_INCOMPAT_ZONE_GAPS)
>
> #define XFS_SB_FEAT_INCOMPAT_UNKNOWN ~XFS_SB_FEAT_INCOMPAT_ALL
> static inline bool
> diff --git a/fs/xfs/libxfs/xfs_group.h b/fs/xfs/libxfs/xfs_group.h
> index 430a43e1591e..996b29313bc2 100644
> --- a/fs/xfs/libxfs/xfs_group.h
> +++ b/fs/xfs/libxfs/xfs_group.h
> @@ -117,7 +117,11 @@ xfs_gbno_to_daddr(
> struct xfs_groups *g = &mp->m_groups[xg->xg_type];
> xfs_fsblock_t fsbno;
>
> - fsbno = (xfs_fsblock_t)xg->xg_gno * g->blocks + gbno;
> + if (g->has_daddr_gaps)
> + fsbno = xfs_gbno_to_fsb(xg, gbno);
> + else
> + fsbno = (xfs_fsblock_t)xg->xg_gno * g->blocks + gbno;
> +
> return XFS_FSB_TO_BB(mp, g->start_fsb + fsbno);
> }
>
> diff --git a/fs/xfs/libxfs/xfs_rtgroup.h b/fs/xfs/libxfs/xfs_rtgroup.h
> index 85d8d329d417..5b3305e09ec3 100644
> --- a/fs/xfs/libxfs/xfs_rtgroup.h
> +++ b/fs/xfs/libxfs/xfs_rtgroup.h
> @@ -245,11 +245,14 @@ xfs_rtb_to_daddr(
> xfs_rtblock_t rtbno)
> {
> struct xfs_groups *g = &mp->m_groups[XG_TYPE_RTG];
> - xfs_rgnumber_t rgno = xfs_rtb_to_rgno(mp, rtbno);
> - uint64_t start_bno = (xfs_rtblock_t)rgno * g->blocks;
>
> - return XFS_FSB_TO_BB(mp,
> - g->start_fsb + start_bno + (rtbno & g->blkmask));
> + if (xfs_has_rtgroups(mp) && !g->has_daddr_gaps) {
> + xfs_rgnumber_t rgno = xfs_rtb_to_rgno(mp, rtbno);
> +
> + rtbno = (xfs_rtblock_t)rgno * g->blocks + (rtbno & g->blkmask);
> + }
> +
> + return XFS_FSB_TO_BB(mp, g->start_fsb + rtbno);
> }
>
> static inline xfs_rtblock_t
> @@ -261,7 +264,7 @@ xfs_daddr_to_rtb(
> xfs_rfsblock_t bno;
>
> bno = XFS_BB_TO_FSBT(mp, daddr) - g->start_fsb;
> - if (xfs_has_rtgroups(mp)) {
> + if (xfs_has_rtgroups(mp) && !g->has_daddr_gaps) {
> xfs_rgnumber_t rgno;
> uint32_t rgbno;
>
> diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
> index ee56fc22fd06..18e4c4908f94 100644
> --- a/fs/xfs/libxfs/xfs_sb.c
> +++ b/fs/xfs/libxfs/xfs_sb.c
> @@ -1176,6 +1176,9 @@ xfs_sb_mount_rextsize(
> rgs->blklog = mp->m_sb.sb_rgblklog;
> rgs->blkmask = xfs_mask32lo(mp->m_sb.sb_rgblklog);
> rgs->start_fsb = mp->m_sb.sb_rtstart;
> + if (xfs_sb_has_incompat_feature(sbp,
> + XFS_SB_FEAT_INCOMPAT_ZONE_GAPS))
> + rgs->has_daddr_gaps = true;
> } else {
> rgs->blocks = 0;
> rgs->blklog = 0;
> diff --git a/fs/xfs/libxfs/xfs_zones.c b/fs/xfs/libxfs/xfs_zones.c
> index e170d7c13533..c17111f40821 100644
> --- a/fs/xfs/libxfs/xfs_zones.c
> +++ b/fs/xfs/libxfs/xfs_zones.c
> @@ -135,6 +135,7 @@ xfs_zone_validate(
> {
> struct xfs_mount *mp = rtg_mount(rtg);
> struct xfs_groups *g = &mp->m_groups[XG_TYPE_RTG];
> + uint32_t expected_size;
>
> /*
> * Check that the zone capacity matches the rtgroup size stored in the
> @@ -149,11 +150,25 @@ xfs_zone_validate(
> return -EIO;
> }
>
> - if (XFS_BB_TO_FSB(mp, zone->len) != 1 << g->blklog) {
> + if (g->has_daddr_gaps) {
> + expected_size = 1 << g->blklog;
> + } else {
> + if (zone->len != zone->capacity) {
> + xfs_warn(mp,
> +"zone %u has capacity != size ((0x%llx vs 0x%llx)",
> + rtg_rgno(rtg),
> + XFS_BB_TO_FSB(mp, zone->len),
> + XFS_BB_TO_FSB(mp, zone->capacity));
> + return -EIO;
> + }
> + expected_size = g->blocks;
> + }
> +
> + if (XFS_BB_TO_FSB(mp, zone->len) != expected_size) {
> xfs_warn(mp,
> "zone %u length (0x%llx) does match geometry (0x%x).",
> rtg_rgno(rtg), XFS_BB_TO_FSB(mp, zone->len),
> - 1 << g->blklog);
> + expected_size);
> }
>
> switch (zone->type) {
> diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
> index 831d9e09fe72..ec8612c8b71d 100644
> --- a/fs/xfs/xfs_mount.h
> +++ b/fs/xfs/xfs_mount.h
> @@ -97,6 +97,15 @@ struct xfs_groups {
> */
> uint8_t blklog;
>
> + /*
> + * Zoned devices can have gaps beyond the usable capacity of a zone and
> + * the end in the LBA/daddr address space. In other words, the hardware
> + * equivalent to the RT groups already takes care of the power of 2
> + * alignment for us. In this case the sparse FSB/RTB address space maps
> + * 1:1 to the device address space.
> + */
> + bool has_daddr_gaps;
> +
> /*
> * Mask to extract the group-relative block number from a FSB.
> * For a pre-rtgroups filesystem we pretend to have one very large
> --
> 2.45.2
>
>