[075/115] xfs: drop compatibility minimum log size computations for reflink

Commit Message

Darrick J. Wong July 30, 2024, 12:43 a.m. UTC

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

Source kernel commit: 6ed858c7c678218aa8df9d9e75d5e9955c105415

Let's also drop the oversized minimum log computations for reflink and
rmap that were the result of bugs introduced many years ago.

Signed-off-by: Darrick J. Wong <[e-mail]>
Reviewed-by: Allison Henderson <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>
---
 libxfs/xfs_log_rlimit.c |   14 ++++++++++++++
 1 file changed, 14 insertions(+)

Patch

diff --git a/libxfs/xfs_log_rlimit.c b/libxfs/xfs_log_rlimit.c
index a7bbd2933..246d5f486 100644
--- a/libxfs/xfs_log_rlimit.c
+++ b/libxfs/xfs_log_rlimit.c
@@ -24,6 +24,11 @@ 
  * because that can create the situation where a newer mkfs writes a new
  * filesystem that an older kernel won't mount.
  *
+ * Several years prior, we also discovered that the transaction reservations
+ * for rmap and reflink operations were unnecessarily large.  That was fixed,
+ * but the minimum log size computation was left alone to avoid the
+ * compatibility problems noted above.  Fix that too.
+ *
  * Therefore, we only may correct the computation starting with filesystem
  * features that didn't exist in 2023.  In other words, only turn this on if
  * the filesystem has parent pointers.
@@ -80,6 +85,15 @@  xfs_log_calc_trans_resv_for_minlogblocks(
 {
 	unsigned int		rmap_maxlevels = mp->m_rmap_maxlevels;
 
+	/*
+	 * If the feature set is new enough, drop the oversized minimum log
+	 * size computation introduced by the original reflink code.
+	 */
+	if (xfs_want_minlogsize_fixes(&mp->m_sb)) {
+		xfs_trans_resv_calc(mp, resv);
+		return;
+	}
+
 	/*
 	 * In the early days of rmap+reflink, we always set the rmap maxlevels
 	 * to 9 even if the AG was small enough that it would never grow to