[PATCH v2 11/18] xfs: extend transaction reservations for parent attributes

[Allison Henderson <allison.henderson@oracle.com>]

We need to add, remove or modify parent pointer attributes during
create/link/unlink/rename operations atomically with the dirents in the
parent directories being modified. This means they need to be modified
in the same transaction as the parent directories, and so we need to add
the required space for the attribute modifications to the transaction
reservations.

[achender: rebased]

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
---
 fs/xfs/libxfs/xfs_trans_resv.c | 105 +++++++++++++++++++++++++++------
 1 file changed, 86 insertions(+), 19 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_trans_resv.c b/fs/xfs/libxfs/xfs_trans_resv.c
index e9913c2c5a24..b43ac4be7564 100644
--- a/fs/xfs/libxfs/xfs_trans_resv.c
+++ b/fs/xfs/libxfs/xfs_trans_resv.c
@@ -909,24 +909,67 @@ xfs_calc_sb_reservation(
 	return xfs_calc_buf_res(1, mp->m_sb.sb_sectsize);
 }
 
-void
-xfs_trans_resv_calc(
-	struct xfs_mount	*mp,
-	struct xfs_trans_resv	*resp)
+STATIC void
+xfs_calc_parent_ptr_reservations(
+	struct xfs_mount     *mp)
 {
-	int			logcount_adj = 0;
+	struct xfs_trans_resv   *resp = M_RES(mp);
 
-	/*
-	 * The following transactions are logged in physical format and
-	 * require a permanent reservation on space.
-	 */
-	resp->tr_write.tr_logres = xfs_calc_write_reservation(mp, false);
-	resp->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT;
-	resp->tr_write.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
+	/* Calculate extra space needed for parent pointer attributes */
+	if (!xfs_has_parent(mp))
+		return;
 
-	resp->tr_itruncate.tr_logres = xfs_calc_itruncate_reservation(mp, false);
-	resp->tr_itruncate.tr_logcount = XFS_ITRUNCATE_LOG_COUNT;
-	resp->tr_itruncate.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
+	/* rename can add/remove/modify 4 parent attributes */
+	resp->tr_rename.tr_logres += 4 * max(resp->tr_attrsetm.tr_logres,
+					 resp->tr_attrrm.tr_logres);
+	resp->tr_rename.tr_logcount += 4 * max(resp->tr_attrsetm.tr_logcount,
+					   resp->tr_attrrm.tr_logcount);
+
+	/* create will add 1 parent attribute */
+	resp->tr_create.tr_logres += resp->tr_attrsetm.tr_logres;
+	resp->tr_create.tr_logcount += resp->tr_attrsetm.tr_logcount;
+
+	/* mkdir will add 1 parent attribute */
+	resp->tr_mkdir.tr_logres += resp->tr_attrsetm.tr_logres;
+	resp->tr_mkdir.tr_logcount += resp->tr_attrsetm.tr_logcount;
+
+	/* link will add 1 parent attribute */
+	resp->tr_link.tr_logres += resp->tr_attrsetm.tr_logres;
+	resp->tr_link.tr_logcount += resp->tr_attrsetm.tr_logcount;
+
+	/* symlink will add 1 parent attribute */
+	resp->tr_symlink.tr_logres += resp->tr_attrsetm.tr_logres;
+	resp->tr_symlink.tr_logcount += resp->tr_attrsetm.tr_logcount;
+
+	/* remove will remove 1 parent attribute */
+	resp->tr_remove.tr_logres += resp->tr_attrrm.tr_logres;
+	resp->tr_remove.tr_logcount += resp->tr_attrrm.tr_logcount;
+}
+
+/*
+ * Namespace reservations.
+ *
+ * These get tricky when parent pointers are enabled as we have attribute
+ * modifications occurring from within these transactions. Rather than confuse
+ * each of these reservation calculations with the conditional attribute
+ * reservations, add them here in a clear and concise manner. This assumes that
+ * the attribute reservations have already been calculated.
+ *
+ * Note that we only include the static attribute reservation here; the runtime
+ * reservation will have to be modified by the size of the attributes being
+ * added/removed/modified. See the comments on the attribute reservation
+ * calculations for more details.
+ *
+ * Note for rename: rename will vastly overestimate requirements. This will be
+ * addressed later when modifications are made to ensure parent attribute
+ * modifications can be done atomically with the rename operation.
+ */
+STATIC void
+xfs_calc_namespace_reservations(
+	struct xfs_mount	*mp,
+	struct xfs_trans_resv	*resp)
+{
+	ASSERT(resp->tr_attrsetm.tr_logres > 0);
 
 	resp->tr_rename.tr_logres = xfs_calc_rename_reservation(mp);
 	resp->tr_rename.tr_logcount = XFS_RENAME_LOG_COUNT;
@@ -948,15 +991,37 @@ xfs_trans_resv_calc(
 	resp->tr_create.tr_logcount = XFS_CREATE_LOG_COUNT;
 	resp->tr_create.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
 
+	resp->tr_mkdir.tr_logres = xfs_calc_mkdir_reservation(mp);
+	resp->tr_mkdir.tr_logcount = XFS_MKDIR_LOG_COUNT;
+	resp->tr_mkdir.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
+
+	xfs_calc_parent_ptr_reservations(mp);
+}
+
+void
+xfs_trans_resv_calc(
+	struct xfs_mount	*mp,
+	struct xfs_trans_resv	*resp)
+{
+	int			logcount_adj = 0;
+
+	/*
+	 * The following transactions are logged in physical format and
+	 * require a permanent reservation on space.
+	 */
+	resp->tr_write.tr_logres = xfs_calc_write_reservation(mp, false);
+	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, false);
+	resp->tr_itruncate.tr_logcount = XFS_ITRUNCATE_LOG_COUNT;
+	resp->tr_itruncate.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
+
 	resp->tr_create_tmpfile.tr_logres =
 			xfs_calc_create_tmpfile_reservation(mp);
 	resp->tr_create_tmpfile.tr_logcount = XFS_CREATE_TMPFILE_LOG_COUNT;
 	resp->tr_create_tmpfile.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
 
-	resp->tr_mkdir.tr_logres = xfs_calc_mkdir_reservation(mp);
-	resp->tr_mkdir.tr_logcount = XFS_MKDIR_LOG_COUNT;
-	resp->tr_mkdir.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
-
 	resp->tr_ifree.tr_logres = xfs_calc_ifree_reservation(mp);
 	resp->tr_ifree.tr_logcount = XFS_INACTIVE_LOG_COUNT;
 	resp->tr_ifree.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
@@ -986,6 +1051,8 @@ xfs_trans_resv_calc(
 	resp->tr_qm_dqalloc.tr_logcount = XFS_WRITE_LOG_COUNT;
 	resp->tr_qm_dqalloc.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
 
+	xfs_calc_namespace_reservations(mp, resp);
+
 	/*
 	 * The following transactions are logged in logical format with
 	 * a default log count.
-- 
2.25.1