xfs: reduce the absurdly large log reservations

Back in the early days of reflink and rmap development I set the
transaction reservation sizes to be overly generous for rmap+reflink
filesystems, and a little under-generous for rmap-only filesystems.

Since we don't need *eight* transaction rolls to handle three new log
intent items, decrease the logcounts to what we actually need, and amend
the shadow reservation computation function to reflect what we used to
do so that the minimum log size doesn't change.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>

2 files changed, 50 insertions, 15 deletions

diff --git a/fs/xfs/libxfs/xfs_trans_resv.c b/fs/xfs/libxfs/xfs_trans_resv.c
index d40089418d11..c3990fd6fb88 100644
--- a/fs/xfs/libxfs/xfs_trans_resv.c
+++ b/fs/xfs/libxfs/xfs_trans_resv.c
@@ -842,18 +842,11 @@ xfs_trans_resv_calc(
 	 * require a permanent reservation on space.
 	 */
 	resp->tr_write.tr_logres = xfs_calc_write_reservation(mp);
-	if (xfs_sb_version_hasreflink(&mp->m_sb))
-		resp->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT_REFLINK;
-	else
-		resp->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT;
+	resp->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT;
 	resp->tr_write.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
 
 	resp->tr_itruncate.tr_logres = xfs_calc_itruncate_reservation(mp);
-	if (xfs_sb_version_hasreflink(&mp->m_sb))
-		resp->tr_itruncate.tr_logcount =
-				XFS_ITRUNCATE_LOG_COUNT_REFLINK;
-	else
-		resp->tr_itruncate.tr_logcount = XFS_ITRUNCATE_LOG_COUNT;
+	resp->tr_itruncate.tr_logcount = XFS_ITRUNCATE_LOG_COUNT;
 	resp->tr_itruncate.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
 
 	resp->tr_rename.tr_logres = xfs_calc_rename_reservation(mp);
@@ -910,10 +903,7 @@ xfs_trans_resv_calc(
 	resp->tr_growrtalloc.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
 
 	resp->tr_qm_dqalloc.tr_logres = xfs_calc_qm_dqalloc_reservation(mp);
-	if (xfs_sb_version_hasreflink(&mp->m_sb))
-		resp->tr_qm_dqalloc.tr_logcount = XFS_WRITE_LOG_COUNT_REFLINK;
-	else
-		resp->tr_qm_dqalloc.tr_logcount = XFS_WRITE_LOG_COUNT;
+	resp->tr_qm_dqalloc.tr_logcount = XFS_WRITE_LOG_COUNT;
 	resp->tr_qm_dqalloc.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
 
 	/*
@@ -946,6 +936,28 @@ xfs_trans_resv_calc(
 	resp->tr_clearagi.tr_logres = xfs_calc_clear_agi_bucket_reservation(mp);
 	resp->tr_growrtzero.tr_logres = xfs_calc_growrtzero_reservation(mp);
 	resp->tr_growrtfree.tr_logres = xfs_calc_growrtfree_reservation(mp);
+
+	/* Add one logcount for BUI items that appear with rmap or reflink. */
+	if (xfs_sb_version_hasreflink(&mp->m_sb) ||
+	    xfs_sb_version_hasrmapbt(&mp->m_sb)) {
+		resp->tr_itruncate.tr_logcount++;
+		resp->tr_write.tr_logcount++;
+		resp->tr_qm_dqalloc.tr_logcount++;
+	}
+
+	/* Add one logcount for refcount intent items. */
+	if (xfs_sb_version_hasreflink(&mp->m_sb)) {
+		resp->tr_itruncate.tr_logcount++;
+		resp->tr_write.tr_logcount++;
+		resp->tr_qm_dqalloc.tr_logcount++;
+	}
+
+	/* Add one logcount for rmap intent items. */
+	if (xfs_sb_version_hasrmapbt(&mp->m_sb)) {
+		resp->tr_itruncate.tr_logcount++;
+		resp->tr_write.tr_logcount++;
+		resp->tr_qm_dqalloc.tr_logcount++;
+	}
 }
 
 /*
@@ -957,5 +969,26 @@ xfs_trans_resv_calc_logsize(
 	struct xfs_mount	*mp,
 	struct xfs_trans_resv	*resp)
 {
+	ASSERT(resp != M_RES(mp));
+
 	xfs_trans_resv_calc(mp, resp);
+
+	if (xfs_sb_version_hasreflink(&mp->m_sb)) {
+		/*
+		 * In the early days of reflink we set the logcounts absurdly
+		 * high.
+		 */
+		resp->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT_REFLINK;
+		resp->tr_itruncate.tr_logcount =
+				XFS_ITRUNCATE_LOG_COUNT_REFLINK;
+		resp->tr_qm_dqalloc.tr_logcount = XFS_WRITE_LOG_COUNT_REFLINK;
+	} else if (xfs_sb_version_hasrmapbt(&mp->m_sb)) {
+		/*
+		 * In the early days of non-reflink rmap we set the logcount
+		 * too low.
+		 */
+		resp->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT;
+		resp->tr_itruncate.tr_logcount = XFS_ITRUNCATE_LOG_COUNT;
+		resp->tr_qm_dqalloc.tr_logcount = XFS_WRITE_LOG_COUNT;
+	}
 }
diff --git a/fs/xfs/libxfs/xfs_trans_resv.h b/fs/xfs/libxfs/xfs_trans_resv.h
index e69b46f1c41f..6390ba2a6ed0 100644
--- a/fs/xfs/libxfs/xfs_trans_resv.h
+++ b/fs/xfs/libxfs/xfs_trans_resv.h
@@ -75,7 +75,6 @@ struct xfs_trans_resv {
 #define	XFS_DEFAULT_LOG_COUNT		1
 #define	XFS_DEFAULT_PERM_LOG_COUNT	2
 #define	XFS_ITRUNCATE_LOG_COUNT		2
-#define	XFS_ITRUNCATE_LOG_COUNT_REFLINK	8
 #define XFS_INACTIVE_LOG_COUNT		2
 #define	XFS_CREATE_LOG_COUNT		2
 #define	XFS_CREATE_TMPFILE_LOG_COUNT	2
@@ -85,12 +84,15 @@ struct xfs_trans_resv {
 #define	XFS_LINK_LOG_COUNT		2
 #define	XFS_RENAME_LOG_COUNT		2
 #define	XFS_WRITE_LOG_COUNT		2
-#define	XFS_WRITE_LOG_COUNT_REFLINK	8
 #define	XFS_ADDAFORK_LOG_COUNT		2
 #define	XFS_ATTRINVAL_LOG_COUNT		1
 #define	XFS_ATTRSET_LOG_COUNT		3
 #define	XFS_ATTRRM_LOG_COUNT		3
 
+/* Absurdly high log counts from the early days of reflink.  Do not use. */
+#define	XFS_ITRUNCATE_LOG_COUNT_REFLINK	8
+#define	XFS_WRITE_LOG_COUNT_REFLINK	8
+
 void xfs_trans_resv_calc_logsize(struct xfs_mount *mp,
 		struct xfs_trans_resv *resp);
 void xfs_trans_resv_calc(struct xfs_mount *mp, struct xfs_trans_resv *resp);