[XFS] Ondisk format extension for extended attributes (attr2). Basically,

the data/attr forks now grow up/down from either end of the literal area,
rather than dividing the literal area into two chunks and growing both
upward.  Means we can now make much more efficient use of the attribute
space, incl. fitting DMF attributes inline in 256 byte inodes, and large
jumps in dbench3 performance numbers.  It is self enabling, but can be
forced on/off via the attr2/noattr2 mount options.

SGI-PV: 941645
SGI-Modid: xfs-linux:xfs-kern:23835a

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

1 files changed, 66 insertions, 18 deletions

diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index 26645d267f1..3e013530d00 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000-2004 Silicon Graphics, Inc.  All Rights Reserved.
+ * Copyright (c) 2000-2005 Silicon Graphics, Inc.  All Rights Reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of version 2 of the GNU General Public License as
@@ -62,6 +62,7 @@
 #include "xfs_error.h"
 #include "xfs_da_btree.h"
 #include "xfs_dir_leaf.h"
+#include "xfs_attr_leaf.h"
 #include "xfs_bit.h"
 #include "xfs_rw.h"
 #include "xfs_quota.h"
@@ -3337,6 +3338,29 @@ xfs_bmap_insert_exlist(
 }
 
 /*
+ * Helper routine to reset inode di_forkoff field when switching
+ * attribute fork from local to extent format - we reset it where
+ * possible to make space available for inline data fork extents.
+ */
+STATIC void
+xfs_bmap_forkoff_reset(
+	xfs_mount_t	*mp,
+	xfs_inode_t	*ip,
+	int		whichfork)
+{
+	if (whichfork == XFS_ATTR_FORK &&
+	    (ip->i_d.di_format != XFS_DINODE_FMT_DEV) &&
+	    (ip->i_d.di_format != XFS_DINODE_FMT_UUID) &&
+	    ((mp->m_attroffset >> 3) > ip->i_d.di_forkoff)) {
+		ip->i_d.di_forkoff = mp->m_attroffset >> 3;
+		ip->i_df.if_ext_max = XFS_IFORK_DSIZE(ip) /
+					(uint)sizeof(xfs_bmbt_rec_t);
+		ip->i_afp->if_ext_max = XFS_IFORK_ASIZE(ip) /
+					(uint)sizeof(xfs_bmbt_rec_t);
+	}
+}
+
+/*
  * Convert a local file to an extents file.
  * This code is out of bounds for data forks of regular files,
  * since the file data needs to get logged so things will stay consistent.
@@ -3403,6 +3427,7 @@ xfs_bmap_local_to_extents(
 		memcpy((char *)XFS_BUF_PTR(bp), ifp->if_u1.if_data,
 			ifp->if_bytes);
 		xfs_trans_log_buf(tp, bp, 0, ifp->if_bytes - 1);
+		xfs_bmap_forkoff_reset(args.mp, ip, whichfork);
 		xfs_idata_realloc(ip, -ifp->if_bytes, whichfork);
 		xfs_iext_realloc(ip, 1, whichfork);
 		ep = ifp->if_u1.if_extents;
@@ -3413,8 +3438,10 @@ xfs_bmap_local_to_extents(
 		XFS_TRANS_MOD_DQUOT_BYINO(args.mp, tp, ip,
 			XFS_TRANS_DQ_BCOUNT, 1L);
 		flags |= XFS_ILOG_FEXT(whichfork);
-	} else
+	} else {
 		ASSERT(XFS_IFORK_NEXTENTS(ip, whichfork) == 0);
+		xfs_bmap_forkoff_reset(ip->i_mount, ip, whichfork);
+	}
 	ifp->if_flags &= ~XFS_IFINLINE;
 	ifp->if_flags |= XFS_IFEXTENTS;
 	XFS_IFORK_FMT_SET(ip, whichfork, XFS_DINODE_FMT_EXTENTS);
@@ -3796,22 +3823,24 @@ xfs_bunmap_trace(
 int						/* error code */
 xfs_bmap_add_attrfork(
 	xfs_inode_t		*ip,		/* incore inode pointer */
-	int			rsvd)		/* OK to allocated reserved blocks in trans */
+	int			size,		/* space new attribute needs */
+	int			rsvd)		/* xact may use reserved blks */
 {
-	int			blks;		/* space reservation */
-	int			committed;	/* xaction was committed */
-	int			error;		/* error return value */
 	xfs_fsblock_t		firstblock;	/* 1st block/ag allocated */
 	xfs_bmap_free_t		flist;		/* freed extent list */
-	int			logflags;	/* logging flags */
 	xfs_mount_t		*mp;		/* mount structure */
-	unsigned long		s;		/* spinlock spl value */
 	xfs_trans_t		*tp;		/* transaction pointer */
+	unsigned long		s;		/* spinlock spl value */
+	int			blks;		/* space reservation */
+	int			version = 1;	/* superblock attr version */
+	int			committed;	/* xaction was committed */
+	int			logflags;	/* logging flags */
+	int			error;		/* error return value */
 
+	ASSERT(XFS_IFORK_Q(ip) == 0);
 	ASSERT(ip->i_df.if_ext_max ==
 	       XFS_IFORK_DSIZE(ip) / (uint)sizeof(xfs_bmbt_rec_t));
-	if (XFS_IFORK_Q(ip))
-		return 0;
+
 	mp = ip->i_mount;
 	ASSERT(!XFS_NOT_DQATTACHED(mp, ip));
 	tp = xfs_trans_alloc(mp, XFS_TRANS_ADDAFORK);
@@ -3853,7 +3882,11 @@ xfs_bmap_add_attrfork(
 	case XFS_DINODE_FMT_LOCAL:
 	case XFS_DINODE_FMT_EXTENTS:
 	case XFS_DINODE_FMT_BTREE:
-		ip->i_d.di_forkoff = mp->m_attroffset >> 3;
+		ip->i_d.di_forkoff = xfs_attr_shortform_bytesfit(ip, size);
+		if (!ip->i_d.di_forkoff)
+			ip->i_d.di_forkoff = mp->m_attroffset >> 3;
+		else if (!(mp->m_flags & XFS_MOUNT_COMPAT_ATTR))
+			version = 2;
 		break;
 	default:
 		ASSERT(0);
@@ -3890,12 +3923,21 @@ xfs_bmap_add_attrfork(
 		xfs_trans_log_inode(tp, ip, logflags);
 	if (error)
 		goto error2;
-	if (!XFS_SB_VERSION_HASATTR(&mp->m_sb)) {
+	if (!XFS_SB_VERSION_HASATTR(&mp->m_sb) ||
+	   (!XFS_SB_VERSION_HASATTR2(&mp->m_sb) && version == 2)) {
+		logflags = 0;
 		s = XFS_SB_LOCK(mp);
 		if (!XFS_SB_VERSION_HASATTR(&mp->m_sb)) {
 			XFS_SB_VERSION_ADDATTR(&mp->m_sb);
+			logflags |= XFS_SB_VERSIONNUM;
+		}
+		if (!XFS_SB_VERSION_HASATTR2(&mp->m_sb) && version == 2) {
+			XFS_SB_VERSION_ADDATTR2(&mp->m_sb);
+			logflags |= (XFS_SB_VERSIONNUM | XFS_SB_FEATURES2);
+		}
+		if (logflags) {
 			XFS_SB_UNLOCK(mp, s);
-			xfs_mod_sb(tp, XFS_SB_VERSIONNUM);
+			xfs_mod_sb(tp, logflags);
 		} else
 			XFS_SB_UNLOCK(mp, s);
 	}
@@ -3988,13 +4030,19 @@ xfs_bmap_compute_maxlevels(
 	 * (a signed 32-bit number, xfs_extnum_t), or by di_anextents
 	 * (a signed 16-bit number, xfs_aextnum_t).
 	 */
-	maxleafents = (whichfork == XFS_DATA_FORK) ? MAXEXTNUM : MAXAEXTNUM;
+	if (whichfork == XFS_DATA_FORK) {
+		maxleafents = MAXEXTNUM;
+		sz = (mp->m_flags & XFS_MOUNT_COMPAT_ATTR) ?
+			mp->m_attroffset : XFS_BMDR_SPACE_CALC(MINDBTPTRS);
+	} else {
+		maxleafents = MAXAEXTNUM;
+		sz = (mp->m_flags & XFS_MOUNT_COMPAT_ATTR) ?
+			mp->m_sb.sb_inodesize - mp->m_attroffset :
+			XFS_BMDR_SPACE_CALC(MINABTPTRS);
+	}
+	maxrootrecs = (int)XFS_BTREE_BLOCK_MAXRECS(sz, xfs_bmdr, 0);
 	minleafrecs = mp->m_bmap_dmnr[0];
 	minnoderecs = mp->m_bmap_dmnr[1];
-	sz = (whichfork == XFS_DATA_FORK) ?
-		mp->m_attroffset :
-		mp->m_sb.sb_inodesize - mp->m_attroffset;
-	maxrootrecs = (int)XFS_BTREE_BLOCK_MAXRECS(sz, xfs_bmdr, 0);
 	maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
 	for (level = 1; maxblocks > 1; level++) {
 		if (maxblocks <= maxrootrecs)