[PATCH 37/46] xfs: implement busy extent tracking for rtgroups

Darrick J. Wong
2024-12-07T00:01:01Z

From: Darrick J. Wong <djwong@kernel.org>

Source kernel commit: 7e85fc2394115db56be678b617ed646563926581

For rtgroups filesystems, track newly freed (rt) space through the log
until the rt EFIs have been committed to disk. This way we ensure that
space cannot be reused until all traces of the old owner are gone.

As a fringe benefit, we now support -o discard on the realtime device.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
libxfs/xfs_rtbitmap.c | 11 ++++++++++-
libxfs/xfs_rtgroup.h | 13 +++++++++++++
2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/libxfs/xfs_rtbitmap.c b/libxfs/xfs_rtbitmap.c
index e304f07189d3c9..b439fb3c20709f 100644
--- a/libxfs/xfs_rtbitmap.c
+++ b/libxfs/xfs_rtbitmap.c
@@ -1116,6 +1116,7 @@ xfs_rtfree_blocks(
{
struct xfs_mount *mp = tp->t_mountp;
xfs_extlen_t mod;
+ int error;

ASSERT(rtlen <= XFS_MAX_BMBT_EXTLEN);

@@ -1131,8 +1132,16 @@ xfs_rtfree_blocks(
return -EIO;
}

- return xfs_rtfree_extent(tp, rtg, xfs_rtb_to_rtx(mp, rtbno),
+ error = xfs_rtfree_extent(tp, rtg, xfs_rtb_to_rtx(mp, rtbno),
xfs_extlen_to_rtxlen(mp, rtlen));
+ if (error)
+ return error;
+
+ if (xfs_has_rtgroups(mp))
+ xfs_extent_busy_insert(tp, rtg_group(rtg),
+ xfs_rtb_to_rgbno(mp, rtbno), rtlen, 0);
+
+ return 0;
}

/* Find all the free records within a given range. */
diff --git a/libxfs/xfs_rtgroup.h b/libxfs/xfs_rtgroup.h
index 1e51dc62d1143e..7e7e491ff06fa5 100644
--- a/libxfs/xfs_rtgroup.h
+++ b/libxfs/xfs_rtgroup.h
@@ -155,6 +155,19 @@ xfs_rtbno_is_group_start(
return (rtbno & mp->m_groups[XG_TYPE_RTG].blkmask) == 0;
}

+/* Convert an rtgroups rt extent number into an rgbno. */
+static inline xfs_rgblock_t
+xfs_rtx_to_rgbno(
+ struct xfs_rtgroup *rtg,
+ xfs_rtxnum_t rtx)
+{
+ struct xfs_mount *mp = rtg_mount(rtg);
+
+ if (likely(mp->m_rtxblklog >= 0))
+ return rtx << mp->m_rtxblklog;
+ return rtx * mp->m_sb.sb_rextsize;
+}
+
static inline xfs_daddr_t
xfs_rtb_to_daddr(
struct xfs_mount *mp,