[05/37] xfs: realtime rmap btree transaction reservations

Commit Message

Darrick J. Wong Dec. 13, 2024, 1:01 a.m. UTC

From: Darrick J. Wong <[e-mail]>

Make sure that there's enough log reservation to handle mapping
and unmapping realtime extents.  We have to reserve enough space
to handle a split in the rtrmapbt to add the record and a second
split in the regular rmapbt to record the rtrmapbt split.

Signed-off-by: "Darrick J. Wong" <[e-mail]>
---
 fs/xfs/libxfs/xfs_exchmaps.c    |    4 +++-
 fs/xfs/libxfs/xfs_trans_resv.c  |   12 ++++++++++--
 fs/xfs/libxfs/xfs_trans_space.h |   13 +++++++++++++
 3 files changed, 26 insertions(+), 3 deletions(-)

Comments

Christoph Hellwig Dec. 13, 2024, 6:24 a.m. UTC | #1

Looks good:

Reviewed-by: Christoph Hellwig <[e-mail]>

Patch

diff --git a/fs/xfs/libxfs/xfs_exchmaps.c b/fs/xfs/libxfs/xfs_exchmaps.c
index 2021396651de27..3f1d6a98c11819 100644
--- a/fs/xfs/libxfs/xfs_exchmaps.c
+++ b/fs/xfs/libxfs/xfs_exchmaps.c
@@ -662,7 +662,9 @@  xfs_exchmaps_rmapbt_blocks(
 	if (!xfs_has_rmapbt(mp))
 		return 0;
 	if (XFS_IS_REALTIME_INODE(req->ip1))
-		return 0;
+		return howmany_64(req->nr_exchanges,
+					XFS_MAX_CONTIG_RTRMAPS_PER_BLOCK(mp)) *
+			XFS_RTRMAPADD_SPACE_RES(mp);
 
 	return howmany_64(req->nr_exchanges,
 					XFS_MAX_CONTIG_RMAPS_PER_BLOCK(mp)) *
diff --git a/fs/xfs/libxfs/xfs_trans_resv.c b/fs/xfs/libxfs/xfs_trans_resv.c
index bab402340b5da8..f3392eb2d7f41f 100644
--- a/fs/xfs/libxfs/xfs_trans_resv.c
+++ b/fs/xfs/libxfs/xfs_trans_resv.c
@@ -213,7 +213,9 @@  xfs_calc_inode_chunk_res(
  * Per-extent log reservation for the btree changes involved in freeing or
  * allocating a realtime extent.  We have to be able to log as many rtbitmap
  * blocks as needed to mark inuse XFS_BMBT_MAX_EXTLEN blocks' worth of realtime
- * extents, as well as the realtime summary block.
+ * extents, as well as the realtime summary block (t1).  Realtime rmap btree
+ * operations happen in a second transaction, so factor in a couple of rtrmapbt
+ * splits (t2).
  */
 static unsigned int
 xfs_rtalloc_block_count(
@@ -222,10 +224,16 @@  xfs_rtalloc_block_count(
 {
 	unsigned int		rtbmp_blocks;
 	xfs_rtxlen_t		rtxlen;
+	unsigned int		t1, t2 = 0;
 
 	rtxlen = xfs_extlen_to_rtxlen(mp, XFS_MAX_BMBT_EXTLEN);
 	rtbmp_blocks = xfs_rtbitmap_blockcount_len(mp, rtxlen);
-	return (rtbmp_blocks + 1) * num_ops;
+	t1 = (rtbmp_blocks + 1) * num_ops;
+
+	if (xfs_has_rmapbt(mp))
+		t2 = num_ops * (2 * mp->m_rtrmap_maxlevels - 1);
+
+	return max(t1, t2);
 }
 
 /*
diff --git a/fs/xfs/libxfs/xfs_trans_space.h b/fs/xfs/libxfs/xfs_trans_space.h
index 1155ff2d37e29f..d89b570aafcc64 100644
--- a/fs/xfs/libxfs/xfs_trans_space.h
+++ b/fs/xfs/libxfs/xfs_trans_space.h
@@ -14,6 +14,19 @@ 
 #define XFS_MAX_CONTIG_BMAPS_PER_BLOCK(mp)    \
 		(((mp)->m_bmap_dmxr[0]) - ((mp)->m_bmap_dmnr[0]))
 
+/* Worst case number of realtime rmaps that can be held in a block. */
+#define XFS_MAX_CONTIG_RTRMAPS_PER_BLOCK(mp)    \
+		(((mp)->m_rtrmap_mxr[0]) - ((mp)->m_rtrmap_mnr[0]))
+
+/* Adding one realtime rmap could split every level to the top of the tree. */
+#define XFS_RTRMAPADD_SPACE_RES(mp) ((mp)->m_rtrmap_maxlevels)
+
+/* Blocks we might need to add "b" realtime rmaps to a tree. */
+#define XFS_NRTRMAPADD_SPACE_RES(mp, b) \
+	((((b) + XFS_MAX_CONTIG_RTRMAPS_PER_BLOCK(mp) - 1) / \
+	  XFS_MAX_CONTIG_RTRMAPS_PER_BLOCK(mp)) * \
+	  XFS_RTRMAPADD_SPACE_RES(mp))
+
 /* Worst case number of rmaps that can be held in a block. */
 #define XFS_MAX_CONTIG_RMAPS_PER_BLOCK(mp)    \
 		(((mp)->m_rmap_mxr[0]) - ((mp)->m_rmap_mnr[0]))