[PATCH 04/26] xfs: load metadata directory root at mount time

["Darrick J. Wong" <djwong@xxxxxxxxxx>]

From: Darrick J. Wong <djwong@xxxxxxxxxx>

Load the metadata directory root inode into memory at mount time and
release it at unmount time.

Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
 fs/xfs/xfs_mount.c |   31 +++++++++++++++++++++++++++++--
 fs/xfs/xfs_mount.h |    1 +
 2 files changed, 30 insertions(+), 2 deletions(-)


diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 09eef1721ef4f..b0ea88acdb618 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -35,6 +35,7 @@
 #include "xfs_trace.h"
 #include "xfs_ag.h"
 #include "xfs_rtbitmap.h"
+#include "xfs_metafile.h"
 #include "scrub/stats.h"
 
 static DEFINE_MUTEX(xfs_uuid_table_mutex);
@@ -616,6 +617,22 @@ xfs_mount_setup_inode_geom(
 	xfs_ialloc_setup_geometry(mp);
 }
 
+/* Mount the metadata directory tree root. */
+STATIC int
+xfs_mount_setup_metadir(
+	struct xfs_mount	*mp)
+{
+	int			error;
+
+	/* Load the metadata directory root inode into memory. */
+	error = xfs_metafile_iget(mp, mp->m_sb.sb_metadirino, XFS_METAFILE_DIR,
+			&mp->m_metadirip);
+	if (error)
+		xfs_warn(mp, "Failed to load metadir root directory, error %d",
+				error);
+	return error;
+}
+
 /* Compute maximum possible height for per-AG btree types for this fs. */
 static inline void
 xfs_agbtree_compute_maxlevels(
@@ -862,6 +879,12 @@ xfs_mountfs(
 		mp->m_features |= XFS_FEAT_ATTR2;
 	}
 
+	if (xfs_has_metadir(mp)) {
+		error = xfs_mount_setup_metadir(mp);
+		if (error)
+			goto out_free_metadir;
+	}
+
 	/*
 	 * Get and sanity-check the root inode.
 	 * Save the pointer to it in the mount structure.
@@ -872,7 +895,7 @@ xfs_mountfs(
 		xfs_warn(mp,
 			"Failed to read root inode 0x%llx, error %d",
 			sbp->sb_rootino, -error);
-		goto out_log_dealloc;
+		goto out_free_metadir;
 	}
 
 	ASSERT(rip != NULL);
@@ -1014,6 +1037,9 @@ xfs_mountfs(
 	xfs_irele(rip);
 	/* Clean out dquots that might be in memory after quotacheck. */
 	xfs_qm_unmount(mp);
+ out_free_metadir:
+	if (mp->m_metadirip)
+		xfs_irele(mp->m_metadirip);
 
 	/*
 	 * Inactivate all inodes that might still be in memory after a log
@@ -1035,7 +1061,6 @@ xfs_mountfs(
 	 * quota inodes.
 	 */
 	xfs_unmount_flush_inodes(mp);
- out_log_dealloc:
 	xfs_log_mount_cancel(mp);
  out_inodegc_shrinker:
 	shrinker_free(mp->m_inodegc_shrinker);
@@ -1087,6 +1112,8 @@ xfs_unmountfs(
 	xfs_qm_unmount_quotas(mp);
 	xfs_rtunmount_inodes(mp);
 	xfs_irele(mp->m_rootip);
+	if (mp->m_metadirip)
+		xfs_irele(mp->m_metadirip);
 
 	xfs_unmount_flush_inodes(mp);
 
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index d404ce122f238..6251ebced3062 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -93,6 +93,7 @@ typedef struct xfs_mount {
 	struct xfs_inode	*m_rbmip;	/* pointer to bitmap inode */
 	struct xfs_inode	*m_rsumip;	/* pointer to summary inode */
 	struct xfs_inode	*m_rootip;	/* pointer to root directory */
+	struct xfs_inode	*m_metadirip;	/* ptr to metadata directory */
 	struct xfs_quotainfo	*m_quotainfo;	/* disk quota information */
 	struct xfs_buftarg	*m_ddev_targp;	/* data device */
 	struct xfs_buftarg	*m_logdev_targp;/* log device */