On Thu, Jan 02, 2025 at 02:04:10PM +0000, John Garry wrote:
> rtvol guarantees alloc unit alignment through rt_extsize. As such, it is
> possible to atomically write multiple FS blocks in a rtvol (up to
> rt_extsize).
>
> Add a member to xfs_mount to hold the pre-calculated atomic write unit max.
>
> The value in rt_extsize is not necessarily a power-of-2, so find the
> largest power-of-2 evenly divisible into rt_extsize.
>
> Signed-off-by: John Garry <john.g.garry@xxxxxxxxxx>
I guess that works.
Reviewed-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
--D
> ---
> fs/xfs/libxfs/xfs_sb.c | 3 +++
> fs/xfs/xfs_mount.h | 1 +
> fs/xfs/xfs_rtalloc.c | 23 +++++++++++++++++++++++
> fs/xfs/xfs_rtalloc.h | 4 ++++
> 4 files changed, 31 insertions(+)
>
> diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
> index 3b5623611eba..6381060df901 100644
> --- a/fs/xfs/libxfs/xfs_sb.c
> +++ b/fs/xfs/libxfs/xfs_sb.c
> @@ -25,6 +25,7 @@
> #include "xfs_da_format.h"
> #include "xfs_health.h"
> #include "xfs_ag.h"
> +#include "xfs_rtalloc.h"
> #include "xfs_rtbitmap.h"
> #include "xfs_exchrange.h"
> #include "xfs_rtgroup.h"
> @@ -1149,6 +1150,8 @@ xfs_sb_mount_rextsize(
> rgs->blklog = 0;
> rgs->blkmask = (uint64_t)-1;
> }
> +
> + xfs_rt_awu_update(mp);
> }
>
> /* Update incore sb rt extent size, then recompute the cached rt geometry. */
> diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
> index db9dade7d22a..f2f1d2c667cc 100644
> --- a/fs/xfs/xfs_mount.h
> +++ b/fs/xfs/xfs_mount.h
> @@ -191,6 +191,7 @@ typedef struct xfs_mount {
> bool m_fail_unmount;
> bool m_finobt_nores; /* no per-AG finobt resv. */
> bool m_update_sb; /* sb needs update in mount */
> + xfs_extlen_t m_rt_awu_max; /* rt atomic write unit max */
>
> /*
> * Bitsets of per-fs metadata that have been checked and/or are sick.
> diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
> index fcfa6e0eb3ad..e3093f3c7670 100644
> --- a/fs/xfs/xfs_rtalloc.c
> +++ b/fs/xfs/xfs_rtalloc.c
> @@ -735,6 +735,28 @@ xfs_rtginode_ensure(
> return xfs_rtginode_create(rtg, type, true);
> }
>
> +void
> +xfs_rt_awu_update(
> + struct xfs_mount *mp)
> +{
> + xfs_agblock_t rsize = mp->m_sb.sb_rextsize;
> + xfs_extlen_t awu_max;
> +
> + if (is_power_of_2(rsize)) {
> + mp->m_rt_awu_max = rsize;
> + return;
> + }
> +
> + /* Find highest power-of-2 evenly divisible into sb_rextsize */
> + awu_max = 1;
> + while (1) {
> + if (rsize % (awu_max * 2))
> + break;
> + awu_max *= 2;
> + }
> + mp->m_rt_awu_max = awu_max;
> +}
> +
> static struct xfs_mount *
> xfs_growfs_rt_alloc_fake_mount(
> const struct xfs_mount *mp,
> @@ -969,6 +991,7 @@ xfs_growfs_rt_bmblock(
> */
> mp->m_rsumlevels = nmp->m_rsumlevels;
> mp->m_rsumblocks = nmp->m_rsumblocks;
> + mp->m_rt_awu_max = nmp->m_rt_awu_max;
>
> /*
> * Recompute the growfsrt reservation from the new rsumsize.
> diff --git a/fs/xfs/xfs_rtalloc.h b/fs/xfs/xfs_rtalloc.h
> index 8e2a07b8174b..fcb7bb3df470 100644
> --- a/fs/xfs/xfs_rtalloc.h
> +++ b/fs/xfs/xfs_rtalloc.h
> @@ -42,6 +42,10 @@ xfs_growfs_rt(
> struct xfs_mount *mp, /* file system mount structure */
> xfs_growfs_rt_t *in); /* user supplied growfs struct */
>
> +void
> +xfs_rt_awu_update(
> + struct xfs_mount *mp);
> +
> int xfs_rtalloc_reinit_frextents(struct xfs_mount *mp);
> #else
> # define xfs_growfs_rt(mp,in) (-ENOSYS)
> --
> 2.31.1
>
>
