[XFS] Rework DMAPI bulkstat calls in such a way that we can directly

extract inline attributes out of the bulkstat buffer (for that case),
rather than using an (extremely expensive for large icount filesystems)
iget for fetching attrs.

SGI-PV: 944409
SGI-Modid: xfs-linux-melb:xfs-kern:26602a

Signed-off-by: Nathan Scott <nathans@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

2 files changed, 61 insertions, 15 deletions

diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
index 7521f301ee58..305a9d0436f4 100644
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -253,6 +253,46 @@ xfs_bulkstat_one(
 }
 
 /*
+ * Test to see whether we can use the ondisk inode directly, based
+ * on the given bulkstat flags, filling in dipp accordingly.
+ * Returns zero if the inode is dodgey.
+ */
+STATIC int
+xfs_bulkstat_use_dinode(
+	xfs_mount_t	*mp,
+	int		flags,
+	xfs_buf_t	*bp,
+	int		clustidx,
+	xfs_dinode_t	**dipp)
+{
+	xfs_dinode_t	*dip;
+	unsigned int	aformat;
+
+	*dipp = NULL;
+	if (!bp || (flags & BULKSTAT_FG_IGET))
+		return 1;
+	dip = (xfs_dinode_t *)
+			xfs_buf_offset(bp, clustidx << mp->m_sb.sb_inodelog);
+	if (INT_GET(dip->di_core.di_magic, ARCH_CONVERT) != XFS_DINODE_MAGIC ||
+	    !XFS_DINODE_GOOD_VERSION(
+			INT_GET(dip->di_core.di_version, ARCH_CONVERT)))
+		return 0;
+	if (flags & BULKSTAT_FG_QUICK) {
+		*dipp = dip;
+		return 1;
+	}
+	/* BULKSTAT_FG_INLINE: if attr fork is local, or not there, use it */
+	aformat = INT_GET(dip->di_core.di_aformat, ARCH_CONVERT);
+	if ((XFS_CFORK_Q(&dip->di_core) == 0) ||
+	    (aformat == XFS_DINODE_FMT_LOCAL) ||
+	    (aformat == XFS_DINODE_FMT_EXTENTS && !dip->di_core.di_anextents)) {
+		*dipp = dip;
+		return 1;
+	}
+	return 1;
+}
+
+/*
  * Return stat information in bulk (by-inode) for the filesystem.
  */
 int					/* error status */
@@ -529,7 +569,8 @@ xfs_bulkstat(
 						((chunkidx & nimask) >>
 						 mp->m_sb.sb_inopblog);
 
-					if (flags & BULKSTAT_FG_QUICK) {
+					if (flags & (BULKSTAT_FG_QUICK |
+						     BULKSTAT_FG_INLINE)) {
 						ino = XFS_AGINO_TO_INO(mp, agno,
 								       agino);
 						bno = XFS_AGB_TO_DADDR(mp, agno,
@@ -573,21 +614,25 @@ xfs_bulkstat(
 				be32_add(&irbp->ir_freecount, 1);
 				ino = XFS_AGINO_TO_INO(mp, agno, agino);
 				bno = XFS_AGB_TO_DADDR(mp, agno, agbno);
-				if (flags & BULKSTAT_FG_QUICK) {
-					dip = (xfs_dinode_t *)xfs_buf_offset(bp,
-					      (clustidx << mp->m_sb.sb_inodelog));
-
-					if (INT_GET(dip->di_core.di_magic, ARCH_CONVERT)
-						    != XFS_DINODE_MAGIC
-					    || !XFS_DINODE_GOOD_VERSION(
-						    INT_GET(dip->di_core.di_version, ARCH_CONVERT)))
-						continue;
+				if (!xfs_bulkstat_use_dinode(mp, flags, bp,
+							     clustidx, &dip))
+					continue;
+				/*
+				 * If we need to do an iget, cannot hold bp.
+				 * Drop it, until starting the next cluster.
+				 */
+				if ((flags & BULKSTAT_FG_INLINE) && !dip) {
+					if (bp)
+						xfs_buf_relse(bp);
+					bp = NULL;
 				}
 
 				/*
 				 * Get the inode and fill in a single buffer.
 				 * BULKSTAT_FG_QUICK uses dip to fill it in.
 				 * BULKSTAT_FG_IGET uses igets.
+				 * BULKSTAT_FG_INLINE uses dip if we have an
+				 * inline attr fork, else igets.
 				 * See: xfs_bulkstat_one & xfs_dm_bulkstat_one.
 				 * This is also used to count inodes/blks, etc
 				 * in xfs_qm_quotacheck.
diff --git a/fs/xfs/xfs_itable.h b/fs/xfs/xfs_itable.h
index be5f12e07d22..6926c373a0a9 100644
--- a/fs/xfs/xfs_itable.h
+++ b/fs/xfs/xfs_itable.h
@@ -36,15 +36,16 @@ typedef int (*bulkstat_one_pf)(struct xfs_mount	*mp,
 /*
  * Values for stat return value.
  */
-#define	BULKSTAT_RV_NOTHING	0
-#define	BULKSTAT_RV_DIDONE	1
-#define	BULKSTAT_RV_GIVEUP	2
+#define BULKSTAT_RV_NOTHING	0
+#define BULKSTAT_RV_DIDONE	1
+#define BULKSTAT_RV_GIVEUP	2
 
 /*
  * Values for bulkstat flag argument.
  */
-#define	BULKSTAT_FG_IGET	0x1	/* Go through the buffer cache */
-#define	BULKSTAT_FG_QUICK	0x2	/* No iget, walk the dinode cluster */
+#define BULKSTAT_FG_IGET	0x1	/* Go through the buffer cache */
+#define BULKSTAT_FG_QUICK	0x2	/* No iget, walk the dinode cluster */
+#define BULKSTAT_FG_INLINE	0x4	/* No iget if inline attrs */
 
 /*
  * Return stat information in bulk (by-inode) for the filesystem.