patch-2.4.25 linux-2.4.25/fs/xfs/xfs_ialloc.c

Next file: linux-2.4.25/fs/xfs/xfs_ialloc.h
Previous file: linux-2.4.25/fs/xfs/xfs_fsops.h
Back to the patch index
Back to the overall index

diff -urN linux-2.4.24/fs/xfs/xfs_ialloc.c linux-2.4.25/fs/xfs/xfs_ialloc.c
@@ -0,0 +1,1402 @@
+/*
+ * Copyright (c) 2000-2002 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
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * Further, this software is distributed without any warranty that it is
+ * free of the rightful claim of any third person regarding infringement
+ * or the like.  Any license provided herein, whether implied or
+ * otherwise, applies only to this software file.  Patent licenses, if
+ * any, provided herein do not apply to combinations of this program with
+ * other software, or any other product whatsoever.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write the Free Software Foundation, Inc., 59
+ * Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
+ * Mountain View, CA  94043, or:
+ *
+ * http://www.sgi.com
+ *
+ * For further information regarding this notice, see:
+ *
+ * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
+ */
+
+#include "xfs.h"
+
+#include "xfs_macros.h"
+#include "xfs_types.h"
+#include "xfs_inum.h"
+#include "xfs_log.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_ag.h"
+#include "xfs_dir.h"
+#include "xfs_dir2.h"
+#include "xfs_dmapi.h"
+#include "xfs_mount.h"
+#include "xfs_alloc_btree.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_btree.h"
+#include "xfs_ialloc.h"
+#include "xfs_attr_sf.h"
+#include "xfs_dir_sf.h"
+#include "xfs_dir2_sf.h"
+#include "xfs_dinode.h"
+#include "xfs_inode.h"
+#include "xfs_alloc.h"
+#include "xfs_bit.h"
+#include "xfs_rtalloc.h"
+#include "xfs_error.h"
+#include "xfs_bmap.h"
+
+/*
+ * Log specified fields for the inode given by bp and off.
+ */
+STATIC void
+xfs_ialloc_log_di(
+	xfs_trans_t	*tp,		/* transaction pointer */
+	xfs_buf_t	*bp,		/* inode buffer */
+	int		off,		/* index of inode in buffer */
+	int		fields)		/* bitmask of fields to log */
+{
+	int			first;		/* first byte number */
+	int			ioffset;	/* off in bytes */
+	int			last;		/* last byte number */
+	xfs_mount_t		*mp;		/* mount point structure */
+	static const short	offsets[] = {	/* field offsets */
+						/* keep in sync with bits */
+		offsetof(xfs_dinode_core_t, di_magic),
+		offsetof(xfs_dinode_core_t, di_mode),
+		offsetof(xfs_dinode_core_t, di_version),
+		offsetof(xfs_dinode_core_t, di_format),
+		offsetof(xfs_dinode_core_t, di_onlink),
+		offsetof(xfs_dinode_core_t, di_uid),
+		offsetof(xfs_dinode_core_t, di_gid),
+		offsetof(xfs_dinode_core_t, di_nlink),
+		offsetof(xfs_dinode_core_t, di_projid),
+		offsetof(xfs_dinode_core_t, di_pad),
+		offsetof(xfs_dinode_core_t, di_atime),
+		offsetof(xfs_dinode_core_t, di_mtime),
+		offsetof(xfs_dinode_core_t, di_ctime),
+		offsetof(xfs_dinode_core_t, di_size),
+		offsetof(xfs_dinode_core_t, di_nblocks),
+		offsetof(xfs_dinode_core_t, di_extsize),
+		offsetof(xfs_dinode_core_t, di_nextents),
+		offsetof(xfs_dinode_core_t, di_anextents),
+		offsetof(xfs_dinode_core_t, di_forkoff),
+		offsetof(xfs_dinode_core_t, di_aformat),
+		offsetof(xfs_dinode_core_t, di_dmevmask),
+		offsetof(xfs_dinode_core_t, di_dmstate),
+		offsetof(xfs_dinode_core_t, di_flags),
+		offsetof(xfs_dinode_core_t, di_gen),
+		offsetof(xfs_dinode_t, di_next_unlinked),
+		offsetof(xfs_dinode_t, di_u),
+		offsetof(xfs_dinode_t, di_a),
+		sizeof(xfs_dinode_t)
+	};
+
+
+	ASSERT(offsetof(xfs_dinode_t, di_core) == 0);
+	ASSERT((fields & (XFS_DI_U|XFS_DI_A)) == 0);
+	mp = tp->t_mountp;
+	/*
+	 * Get the inode-relative first and last bytes for these fields
+	 */
+	xfs_btree_offsets(fields, offsets, XFS_DI_NUM_BITS, &first, &last);
+	/*
+	 * Convert to buffer offsets and log it.
+	 */
+	ioffset = off << mp->m_sb.sb_inodelog;
+	first += ioffset;
+	last += ioffset;
+	xfs_trans_log_buf(tp, bp, first, last);
+}
+
+/*
+ * Allocation group level functions.
+ */
+
+/*
+ * Allocate new inodes in the allocation group specified by agbp.
+ * Return 0 for success, else error code.
+ */
+STATIC int				/* error code or 0 */
+xfs_ialloc_ag_alloc(
+	xfs_trans_t	*tp,		/* transaction pointer */
+	xfs_buf_t	*agbp,		/* alloc group buffer */
+	int		*alloc)
+{
+	xfs_agi_t	*agi;		/* allocation group header */
+	xfs_alloc_arg_t	args;		/* allocation argument structure */
+	int		blks_per_cluster;  /* fs blocks per inode cluster */
+	xfs_btree_cur_t	*cur;		/* inode btree cursor */
+	xfs_daddr_t	d;		/* disk addr of buffer */
+	int		error;
+	xfs_buf_t	*fbuf;		/* new free inodes' buffer */
+	xfs_dinode_t	*free;		/* new free inode structure */
+	int		i;		/* inode counter */
+	int		j;		/* block counter */
+	int		nbufs;		/* num bufs of new inodes */
+	xfs_agino_t	newino;		/* new first inode's number */
+	xfs_agino_t	newlen;		/* new number of inodes */
+	int		ninodes;	/* num inodes per buf */
+	xfs_agino_t	thisino;	/* current inode number, for loop */
+	int		version;	/* inode version number to use */
+	int		isaligned;	/* inode allocation at stripe unit */
+					/* boundary */
+	xfs_dinode_core_t dic;          /* a dinode_core to copy to new */
+					/* inodes */
+
+	args.tp = tp;
+	args.mp = tp->t_mountp;
+
+	/*
+	 * Locking will ensure that we don't have two callers in here
+	 * at one time.
+	 */
+	newlen = XFS_IALLOC_INODES(args.mp);
+	if (args.mp->m_maxicount &&
+	    args.mp->m_sb.sb_icount + newlen > args.mp->m_maxicount)
+		return XFS_ERROR(ENOSPC);
+	args.minlen = args.maxlen = XFS_IALLOC_BLOCKS(args.mp);
+	/*
+	 * Set the alignment for the allocation.
+	 * If stripe alignment is turned on then align at stripe unit
+	 * boundary.
+	 * If the cluster size is smaller than a filesystem block
+	 * then we're doing I/O for inodes in filesystem block size pieces,
+	 * so don't need alignment anyway.
+	 */
+	isaligned = 0;
+	if (args.mp->m_sinoalign) {
+		ASSERT(!(args.mp->m_flags & XFS_MOUNT_NOALIGN));
+		args.alignment = args.mp->m_dalign;
+		isaligned = 1;
+	} else if (XFS_SB_VERSION_HASALIGN(&args.mp->m_sb) &&
+	    args.mp->m_sb.sb_inoalignmt >=
+	    XFS_B_TO_FSBT(args.mp, XFS_INODE_CLUSTER_SIZE(args.mp)))
+		args.alignment = args.mp->m_sb.sb_inoalignmt;
+	else
+		args.alignment = 1;
+	agi = XFS_BUF_TO_AGI(agbp);
+	/*
+	 * Need to figure out where to allocate the inode blocks.
+	 * Ideally they should be spaced out through the a.g.
+	 * For now, just allocate blocks up front.
+	 */
+	args.agbno = INT_GET(agi->agi_root, ARCH_CONVERT);
+	args.fsbno = XFS_AGB_TO_FSB(args.mp, INT_GET(agi->agi_seqno, ARCH_CONVERT),
+				    args.agbno);
+	/*
+	 * Allocate a fixed-size extent of inodes.
+	 */
+	args.type = XFS_ALLOCTYPE_NEAR_BNO;
+	args.mod = args.total = args.wasdel = args.isfl = args.userdata =
+		args.minalignslop = 0;
+	args.prod = 1;
+	/*
+	 * Allow space for the inode btree to split.
+	 */
+	args.minleft = XFS_IN_MAXLEVELS(args.mp) - 1;
+	if ((error = xfs_alloc_vextent(&args)))
+		return error;
+
+	/*
+	 * If stripe alignment is turned on, then try again with cluster
+	 * alignment.
+	 */
+	if (isaligned && args.fsbno == NULLFSBLOCK) {
+		args.type = XFS_ALLOCTYPE_NEAR_BNO;
+		args.agbno = INT_GET(agi->agi_root, ARCH_CONVERT);
+		args.fsbno = XFS_AGB_TO_FSB(args.mp,
+				INT_GET(agi->agi_seqno, ARCH_CONVERT), args.agbno);
+		if (XFS_SB_VERSION_HASALIGN(&args.mp->m_sb) &&
+			args.mp->m_sb.sb_inoalignmt >=
+			XFS_B_TO_FSBT(args.mp, XFS_INODE_CLUSTER_SIZE(args.mp)))
+				args.alignment = args.mp->m_sb.sb_inoalignmt;
+		else
+			args.alignment = 1;
+		if ((error = xfs_alloc_vextent(&args)))
+			return error;
+	}
+
+	if (args.fsbno == NULLFSBLOCK) {
+		*alloc = 0;
+		return 0;
+	}
+	ASSERT(args.len == args.minlen);
+	/*
+	 * Convert the results.
+	 */
+	newino = XFS_OFFBNO_TO_AGINO(args.mp, args.agbno, 0);
+	/*
+	 * Loop over the new block(s), filling in the inodes.
+	 * For small block sizes, manipulate the inodes in buffers
+	 * which are multiples of the blocks size.
+	 */
+	if (args.mp->m_sb.sb_blocksize >= XFS_INODE_CLUSTER_SIZE(args.mp)) {
+		blks_per_cluster = 1;
+		nbufs = (int)args.len;
+		ninodes = args.mp->m_sb.sb_inopblock;
+	} else {
+		blks_per_cluster = XFS_INODE_CLUSTER_SIZE(args.mp) /
+				   args.mp->m_sb.sb_blocksize;
+		nbufs = (int)args.len / blks_per_cluster;
+		ninodes = blks_per_cluster * args.mp->m_sb.sb_inopblock;
+	}
+	/*
+	 * Figure out what version number to use in the inodes we create.
+	 * If the superblock version has caught up to the one that supports
+	 * the new inode format, then use the new inode version.  Otherwise
+	 * use the old version so that old kernels will continue to be
+	 * able to use the file system.
+	 */
+	if (XFS_SB_VERSION_HASNLINK(&args.mp->m_sb))
+		version = XFS_DINODE_VERSION_2;
+	else
+		version = XFS_DINODE_VERSION_1;
+
+	memset(&dic, 0, sizeof(xfs_dinode_core_t));
+	INT_SET(dic.di_magic, ARCH_CONVERT, XFS_DINODE_MAGIC);
+	INT_SET(dic.di_version, ARCH_CONVERT, version);
+
+	for (j = 0; j < nbufs; j++) {
+		/*
+		 * Get the block.
+		 */
+		d = XFS_AGB_TO_DADDR(args.mp, INT_GET(agi->agi_seqno, ARCH_CONVERT),
+				     args.agbno + (j * blks_per_cluster));
+		fbuf = xfs_trans_get_buf(tp, args.mp->m_ddev_targp, d,
+					 args.mp->m_bsize * blks_per_cluster,
+					 XFS_BUF_LOCK);
+		ASSERT(fbuf);
+		ASSERT(!XFS_BUF_GETERROR(fbuf));
+		/*
+		 * Loop over the inodes in this buffer.
+		 */
+
+		for (i = 0; i < ninodes; i++) {
+			free = XFS_MAKE_IPTR(args.mp, fbuf, i);
+			memcpy(&(free->di_core), &dic, sizeof(xfs_dinode_core_t));
+			INT_SET(free->di_next_unlinked, ARCH_CONVERT, NULLAGINO);
+			xfs_ialloc_log_di(tp, fbuf, i,
+				XFS_DI_CORE_BITS | XFS_DI_NEXT_UNLINKED);
+		}
+		xfs_trans_inode_alloc_buf(tp, fbuf);
+	}
+	INT_MOD(agi->agi_count, ARCH_CONVERT, newlen);
+	INT_MOD(agi->agi_freecount, ARCH_CONVERT, newlen);
+	down_read(&args.mp->m_peraglock);
+	args.mp->m_perag[INT_GET(agi->agi_seqno, ARCH_CONVERT)].pagi_freecount += newlen;
+	up_read(&args.mp->m_peraglock);
+	INT_SET(agi->agi_newino, ARCH_CONVERT, newino);
+	/*
+	 * Insert records describing the new inode chunk into the btree.
+	 */
+	cur = xfs_btree_init_cursor(args.mp, tp, agbp,
+			INT_GET(agi->agi_seqno, ARCH_CONVERT),
+			XFS_BTNUM_INO, (xfs_inode_t *)0, 0);
+	for (thisino = newino;
+	     thisino < newino + newlen;
+	     thisino += XFS_INODES_PER_CHUNK) {
+		if ((error = xfs_inobt_lookup_eq(cur, thisino,
+				XFS_INODES_PER_CHUNK, XFS_INOBT_ALL_FREE, &i))) {
+			xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
+			return error;
+		}
+		ASSERT(i == 0);
+		if ((error = xfs_inobt_insert(cur, &i))) {
+			xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
+			return error;
+		}
+		ASSERT(i == 1);
+	}
+	xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+	/*
+	 * Log allocation group header fields
+	 */
+	xfs_ialloc_log_agi(tp, agbp,
+		XFS_AGI_COUNT | XFS_AGI_FREECOUNT | XFS_AGI_NEWINO);
+	/*
+	 * Modify/log superblock values for inode count and inode free count.
+	 */
+	xfs_trans_mod_sb(tp, XFS_TRANS_SB_ICOUNT, (long)newlen);
+	xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, (long)newlen);
+	*alloc = 1;
+	return 0;
+}
+
+STATIC __inline xfs_agnumber_t
+xfs_ialloc_next_ag(
+	xfs_mount_t	*mp)
+{
+	xfs_agnumber_t	agno;
+
+	spin_lock(&mp->m_agirotor_lock);
+	agno = mp->m_agirotor;
+	if (++mp->m_agirotor == mp->m_maxagi)
+		mp->m_agirotor = 0;
+	spin_unlock(&mp->m_agirotor_lock);
+
+	return agno;
+}
+
+/*
+ * Select an allocation group to look for a free inode in, based on the parent
+ * inode and then mode.  Return the allocation group buffer.
+ */
+STATIC xfs_buf_t *			/* allocation group buffer */
+xfs_ialloc_ag_select(
+	xfs_trans_t	*tp,		/* transaction pointer */
+	xfs_ino_t	parent,		/* parent directory inode number */
+	mode_t		mode,		/* bits set to indicate file type */
+	int		okalloc)	/* ok to allocate more space */
+{
+	xfs_buf_t	*agbp;		/* allocation group header buffer */
+	xfs_agnumber_t	agcount;	/* number of ag's in the filesystem */
+	xfs_agnumber_t	agno;		/* current ag number */
+	int		flags;		/* alloc buffer locking flags */
+	xfs_extlen_t	ineed;		/* blocks needed for inode allocation */
+	xfs_extlen_t	longest = 0;	/* longest extent available */
+	xfs_mount_t	*mp;		/* mount point structure */
+	int		needspace;	/* file mode implies space allocated */
+	xfs_perag_t	*pag;		/* per allocation group data */
+	xfs_agnumber_t	pagno;		/* parent (starting) ag number */
+
+	/*
+	 * Files of these types need at least one block if length > 0
+	 * (and they won't fit in the inode, but that's hard to figure out).
+	 */
+	needspace = S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode);
+	mp = tp->t_mountp;
+	agcount = mp->m_maxagi;
+	if (S_ISDIR(mode))
+		pagno = xfs_ialloc_next_ag(mp);
+	else {
+		pagno = XFS_INO_TO_AGNO(mp, parent);
+		if (pagno >= agcount)
+			pagno = 0;
+	}
+	ASSERT(pagno < agcount);
+	/*
+	 * Loop through allocation groups, looking for one with a little
+	 * free space in it.  Note we don't look for free inodes, exactly.
+	 * Instead, we include whether there is a need to allocate inodes
+	 * to mean that blocks must be allocated for them,
+	 * if none are currently free.
+	 */
+	agno = pagno;
+	flags = XFS_ALLOC_FLAG_TRYLOCK;
+	down_read(&mp->m_peraglock);
+	for (;;) {
+		pag = &mp->m_perag[agno];
+		if (!pag->pagi_init) {
+			if (xfs_ialloc_read_agi(mp, tp, agno, &agbp)) {
+				agbp = NULL;
+				goto nextag;
+			}
+		} else
+			agbp = NULL;
+
+		if (!pag->pagi_inodeok) {
+			xfs_ialloc_next_ag(mp);
+			goto unlock_nextag;
+		}
+
+		/*
+		 * Is there enough free space for the file plus a block
+		 * of inodes (if we need to allocate some)?
+		 */
+		ineed = pag->pagi_freecount ? 0 : XFS_IALLOC_BLOCKS(mp);
+		if (ineed && !pag->pagf_init) {
+			if (agbp == NULL &&
+			    xfs_ialloc_read_agi(mp, tp, agno, &agbp)) {
+				agbp = NULL;
+				goto nextag;
+			}
+			(void)xfs_alloc_pagf_init(mp, tp, agno, flags);
+		}
+		if (!ineed || pag->pagf_init) {
+			if (ineed && !(longest = pag->pagf_longest))
+				longest = pag->pagf_flcount > 0;
+			if (!ineed ||
+			    (pag->pagf_freeblks >= needspace + ineed &&
+			     longest >= ineed &&
+			     okalloc)) {
+				if (agbp == NULL &&
+				    xfs_ialloc_read_agi(mp, tp, agno, &agbp)) {
+					agbp = NULL;
+					goto nextag;
+				}
+				up_read(&mp->m_peraglock);
+				return agbp;
+			}
+		}
+unlock_nextag:
+		if (agbp)
+			xfs_trans_brelse(tp, agbp);
+nextag:
+		/*
+		 * No point in iterating over the rest, if we're shutting
+		 * down.
+		 */
+		if (XFS_FORCED_SHUTDOWN(mp)) {
+			up_read(&mp->m_peraglock);
+			return (xfs_buf_t *)0;
+		}
+		agno++;
+		if (agno >= agcount)
+			agno = 0;
+		if (agno == pagno) {
+			if (flags == 0) {
+				up_read(&mp->m_peraglock);
+				return (xfs_buf_t *)0;
+			}
+			flags = 0;
+		}
+	}
+}
+
+/*
+ * Visible inode allocation functions.
+ */
+
+/*
+ * Allocate an inode on disk.
+ * Mode is used to tell whether the new inode will need space, and whether
+ * it is a directory.
+ *
+ * The arguments IO_agbp and alloc_done are defined to work within
+ * the constraint of one allocation per transaction.
+ * xfs_dialloc() is designed to be called twice if it has to do an
+ * allocation to make more free inodes.  On the first call,
+ * IO_agbp should be set to NULL. If an inode is available,
+ * i.e., xfs_dialloc() did not need to do an allocation, an inode
+ * number is returned.  In this case, IO_agbp would be set to the
+ * current ag_buf and alloc_done set to false.
+ * If an allocation needed to be done, xfs_dialloc would return
+ * the current ag_buf in IO_agbp and set alloc_done to true.
+ * The caller should then commit the current transaction, allocate a new
+ * transaction, and call xfs_dialloc() again, passing in the previous
+ * value of IO_agbp.  IO_agbp should be held across the transactions.
+ * Since the agbp is locked across the two calls, the second call is
+ * guaranteed to have a free inode available.
+ *
+ * Once we successfully pick an inode its number is returned and the
+ * on-disk data structures are updated.  The inode itself is not read
+ * in, since doing so would break ordering constraints with xfs_reclaim.
+ */
+int
+xfs_dialloc(
+	xfs_trans_t	*tp,		/* transaction pointer */
+	xfs_ino_t	parent,		/* parent inode (directory) */
+	mode_t		mode,		/* mode bits for new inode */
+	int		okalloc,	/* ok to allocate more space */
+	xfs_buf_t	**IO_agbp,	/* in/out ag header's buffer */
+	boolean_t	*alloc_done,	/* true if we needed to replenish
+					   inode freelist */
+	xfs_ino_t	*inop)		/* inode number allocated */
+{
+	xfs_agnumber_t	agcount;	/* number of allocation groups */
+	xfs_buf_t	*agbp;		/* allocation group header's buffer */
+	xfs_agnumber_t	agno;		/* allocation group number */
+	xfs_agi_t	*agi;		/* allocation group header structure */
+	xfs_btree_cur_t	*cur;		/* inode allocation btree cursor */
+	int		error;		/* error return value */
+	int		i;		/* result code */
+	int		ialloced;	/* inode allocation status */
+	int		noroom = 0;	/* no space for inode blk allocation */
+	xfs_ino_t	ino;		/* fs-relative inode to be returned */
+	/* REFERENCED */
+	int		j;		/* result code */
+	xfs_mount_t	*mp;		/* file system mount structure */
+	int		offset;		/* index of inode in chunk */
+	xfs_agino_t	pagino;		/* parent's a.g. relative inode # */
+	xfs_agnumber_t	pagno;		/* parent's allocation group number */
+	xfs_inobt_rec_t	rec;		/* inode allocation record */
+	xfs_agnumber_t	tagno;		/* testing allocation group number */
+	xfs_btree_cur_t	*tcur;		/* temp cursor */
+	xfs_inobt_rec_t	trec;		/* temp inode allocation record */
+
+
+	if (*IO_agbp == NULL) {
+		/*
+		 * We do not have an agbp, so select an initial allocation
+		 * group for inode allocation.
+		 */
+		agbp = xfs_ialloc_ag_select(tp, parent, mode, okalloc);
+		/*
+		 * Couldn't find an allocation group satisfying the
+		 * criteria, give up.
+		 */
+		if (!agbp) {
+			*inop = NULLFSINO;
+			return 0;
+		}
+		agi = XFS_BUF_TO_AGI(agbp);
+		ASSERT(INT_GET(agi->agi_magicnum, ARCH_CONVERT) == XFS_AGI_MAGIC);
+	} else {
+		/*
+		 * Continue where we left off before.  In this case, we
+		 * know that the allocation group has free inodes.
+		 */
+		agbp = *IO_agbp;
+		agi = XFS_BUF_TO_AGI(agbp);
+		ASSERT(INT_GET(agi->agi_magicnum, ARCH_CONVERT) == XFS_AGI_MAGIC);
+		ASSERT(INT_GET(agi->agi_freecount, ARCH_CONVERT) > 0);
+	}
+	mp = tp->t_mountp;
+	agcount = mp->m_sb.sb_agcount;
+	agno = INT_GET(agi->agi_seqno, ARCH_CONVERT);
+	tagno = agno;
+	pagno = XFS_INO_TO_AGNO(mp, parent);
+	pagino = XFS_INO_TO_AGINO(mp, parent);
+
+	/*
+	 * If we have already hit the ceiling of inode blocks then clear
+	 * okalloc so we scan all available agi structures for a free
+	 * inode.
+	 */
+
+	if (mp->m_maxicount &&
+	    mp->m_sb.sb_icount + XFS_IALLOC_INODES(mp) > mp->m_maxicount) {
+		noroom = 1;
+		okalloc = 0;
+	}
+
+	/*
+	 * Loop until we find an allocation group that either has free inodes
+	 * or in which we can allocate some inodes.  Iterate through the
+	 * allocation groups upward, wrapping at the end.
+	 */
+	*alloc_done = B_FALSE;
+	while (INT_ISZERO(agi->agi_freecount, ARCH_CONVERT)) {
+		/*
+		 * Don't do anything if we're not supposed to allocate
+		 * any blocks, just go on to the next ag.
+		 */
+		if (okalloc) {
+			/*
+			 * Try to allocate some new inodes in the allocation
+			 * group.
+			 */
+			if ((error = xfs_ialloc_ag_alloc(tp, agbp, &ialloced))) {
+				xfs_trans_brelse(tp, agbp);
+				if (error == ENOSPC) {
+					*inop = NULLFSINO;
+					return 0;
+				} else
+					return error;
+			}
+			if (ialloced) {
+				/*
+				 * We successfully allocated some inodes, return
+				 * the current context to the caller so that it
+				 * can commit the current transaction and call
+				 * us again where we left off.
+				 */
+				ASSERT(INT_GET(agi->agi_freecount, ARCH_CONVERT) > 0);
+				*alloc_done = B_TRUE;
+				*IO_agbp = agbp;
+				*inop = NULLFSINO;
+				return 0;
+			}
+		}
+		/*
+		 * If it failed, give up on this ag.
+		 */
+		xfs_trans_brelse(tp, agbp);
+		/*
+		 * Go on to the next ag: get its ag header.
+		 */
+nextag:
+		if (++tagno == agcount)
+			tagno = 0;
+		if (tagno == agno) {
+			*inop = NULLFSINO;
+			return noroom ? ENOSPC : 0;
+		}
+		down_read(&mp->m_peraglock);
+		if (mp->m_perag[tagno].pagi_inodeok == 0) {
+			up_read(&mp->m_peraglock);
+			goto nextag;
+		}
+		error = xfs_ialloc_read_agi(mp, tp, tagno, &agbp);
+		up_read(&mp->m_peraglock);
+		if (error)
+			goto nextag;
+		agi = XFS_BUF_TO_AGI(agbp);
+		ASSERT(INT_GET(agi->agi_magicnum, ARCH_CONVERT) == XFS_AGI_MAGIC);
+	}
+	/*
+	 * Here with an allocation group that has a free inode.
+	 * Reset agno since we may have chosen a new ag in the
+	 * loop above.
+	 */
+	agno = tagno;
+	*IO_agbp = NULL;
+	cur = xfs_btree_init_cursor(mp, tp, agbp, INT_GET(agi->agi_seqno, ARCH_CONVERT),
+				    XFS_BTNUM_INO, (xfs_inode_t *)0, 0);
+	/*
+	 * If pagino is 0 (this is the root inode allocation) use newino.
+	 * This must work because we've just allocated some.
+	 */
+	if (!pagino)
+		pagino = INT_GET(agi->agi_newino, ARCH_CONVERT);
+#ifdef DEBUG
+	if (cur->bc_nlevels == 1) {
+		int	freecount = 0;
+
+		if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i)))
+			goto error0;
+		XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+		do {
+			if ((error = xfs_inobt_get_rec(cur, &rec.ir_startino,
+					&rec.ir_freecount, &rec.ir_free, &i, ARCH_NOCONVERT)))
+				goto error0;
+			XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+			freecount += rec.ir_freecount;
+			if ((error = xfs_inobt_increment(cur, 0, &i)))
+				goto error0;
+		} while (i == 1);
+
+		ASSERT(freecount == INT_GET(agi->agi_freecount, ARCH_CONVERT) ||
+		       XFS_FORCED_SHUTDOWN(mp));
+	}
+#endif
+	/*
+	 * If in the same a.g. as the parent, try to get near the parent.
+	 */
+	if (pagno == agno) {
+		if ((error = xfs_inobt_lookup_le(cur, pagino, 0, 0, &i)))
+			goto error0;
+		if (i != 0 &&
+		    (error = xfs_inobt_get_rec(cur, &rec.ir_startino,
+			    &rec.ir_freecount, &rec.ir_free, &j, ARCH_NOCONVERT)) == 0 &&
+		    j == 1 &&
+		    rec.ir_freecount > 0) {
+			/*
+			 * Found a free inode in the same chunk
+			 * as parent, done.
+			 */
+		}
+		/*
+		 * In the same a.g. as parent, but parent's chunk is full.
+		 */
+		else {
+			int	doneleft;	/* done, to the left */
+			int	doneright;	/* done, to the right */
+
+			if (error)
+				goto error0;
+			ASSERT(i == 1);
+			ASSERT(j == 1);
+			/*
+			 * Duplicate the cursor, search left & right
+			 * simultaneously.
+			 */
+			if ((error = xfs_btree_dup_cursor(cur, &tcur)))
+				goto error0;
+			/*
+			 * Search left with tcur, back up 1 record.
+			 */
+			if ((error = xfs_inobt_decrement(tcur, 0, &i)))
+				goto error1;
+			doneleft = !i;
+			if (!doneleft) {
+				if ((error = xfs_inobt_get_rec(tcur,
+						&trec.ir_startino,
+						&trec.ir_freecount,
+						&trec.ir_free, &i, ARCH_NOCONVERT)))
+					goto error1;
+				XFS_WANT_CORRUPTED_GOTO(i == 1, error1);
+			}
+			/*
+			 * Search right with cur, go forward 1 record.
+			 */
+			if ((error = xfs_inobt_increment(cur, 0, &i)))
+				goto error1;
+			doneright = !i;
+			if (!doneright) {
+				if ((error = xfs_inobt_get_rec(cur,
+						&rec.ir_startino,
+						&rec.ir_freecount,
+						&rec.ir_free, &i, ARCH_NOCONVERT)))
+					goto error1;
+				XFS_WANT_CORRUPTED_GOTO(i == 1, error1);
+			}
+			/*
+			 * Loop until we find the closest inode chunk
+			 * with a free one.
+			 */
+			while (!doneleft || !doneright) {
+				int	useleft;  /* using left inode
+						     chunk this time */
+
+				/*
+				 * Figure out which block is closer,
+				 * if both are valid.
+				 */
+				if (!doneleft && !doneright)
+					useleft =
+						pagino -
+						(trec.ir_startino +
+						 XFS_INODES_PER_CHUNK - 1) <
+						 rec.ir_startino - pagino;
+				else
+					useleft = !doneleft;
+				/*
+				 * If checking the left, does it have
+				 * free inodes?
+				 */
+				if (useleft && trec.ir_freecount) {
+					/*
+					 * Yes, set it up as the chunk to use.
+					 */
+					rec = trec;
+					xfs_btree_del_cursor(cur,
+						XFS_BTREE_NOERROR);
+					cur = tcur;
+					break;
+				}
+				/*
+				 * If checking the right, does it have
+				 * free inodes?
+				 */
+				if (!useleft && rec.ir_freecount) {
+					/*
+					 * Yes, it's already set up.
+					 */
+					xfs_btree_del_cursor(tcur,
+						XFS_BTREE_NOERROR);
+					break;
+				}
+				/*
+				 * If used the left, get another one
+				 * further left.
+				 */
+				if (useleft) {
+					if ((error = xfs_inobt_decrement(tcur, 0,
+							&i)))
+						goto error1;
+					doneleft = !i;
+					if (!doneleft) {
+						if ((error = xfs_inobt_get_rec(
+							    tcur,
+							    &trec.ir_startino,
+							    &trec.ir_freecount,
+							    &trec.ir_free, &i, ARCH_NOCONVERT)))
+							goto error1;
+						XFS_WANT_CORRUPTED_GOTO(i == 1,
+							error1);
+					}
+				}
+				/*
+				 * If used the right, get another one
+				 * further right.
+				 */
+				else {
+					if ((error = xfs_inobt_increment(cur, 0,
+							&i)))
+						goto error1;
+					doneright = !i;
+					if (!doneright) {
+						if ((error = xfs_inobt_get_rec(
+							    cur,
+							    &rec.ir_startino,
+							    &rec.ir_freecount,
+							    &rec.ir_free, &i, ARCH_NOCONVERT)))
+							goto error1;
+						XFS_WANT_CORRUPTED_GOTO(i == 1,
+							error1);
+					}
+				}
+			}
+			ASSERT(!doneleft || !doneright);
+		}
+	}
+	/*
+	 * In a different a.g. from the parent.
+	 * See if the most recently allocated block has any free.
+	 */
+	else if (INT_GET(agi->agi_newino, ARCH_CONVERT) != NULLAGINO) {
+		if ((error = xfs_inobt_lookup_eq(cur,
+				INT_GET(agi->agi_newino, ARCH_CONVERT), 0, 0, &i)))
+			goto error0;
+		if (i == 1 &&
+		    (error = xfs_inobt_get_rec(cur, &rec.ir_startino,
+			    &rec.ir_freecount, &rec.ir_free, &j, ARCH_NOCONVERT)) == 0 &&
+		    j == 1 &&
+		    rec.ir_freecount > 0) {
+			/*
+			 * The last chunk allocated in the group still has
+			 * a free inode.
+			 */
+		}
+		/*
+		 * None left in the last group, search the whole a.g.
+		 */
+		else {
+			if (error)
+				goto error0;
+			if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i)))
+				goto error0;
+			ASSERT(i == 1);
+			for (;;) {
+				if ((error = xfs_inobt_get_rec(cur,
+						&rec.ir_startino,
+						&rec.ir_freecount, &rec.ir_free,
+						&i, ARCH_NOCONVERT)))
+					goto error0;
+				XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+				if (rec.ir_freecount > 0)
+					break;
+				if ((error = xfs_inobt_increment(cur, 0, &i)))
+					goto error0;
+				XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+			}
+		}
+	}
+	offset = XFS_IALLOC_FIND_FREE(&rec.ir_free);
+	ASSERT(offset >= 0);
+	ASSERT(offset < XFS_INODES_PER_CHUNK);
+	ASSERT((XFS_AGINO_TO_OFFSET(mp, rec.ir_startino) %
+				   XFS_INODES_PER_CHUNK) == 0);
+	ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino + offset);
+	XFS_INOBT_CLR_FREE(&rec, offset, ARCH_NOCONVERT);
+	rec.ir_freecount--;
+	if ((error = xfs_inobt_update(cur, rec.ir_startino, rec.ir_freecount,
+			rec.ir_free)))
+		goto error0;
+	INT_MOD(agi->agi_freecount, ARCH_CONVERT, -1);
+	xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT);
+	down_read(&mp->m_peraglock);
+	mp->m_perag[tagno].pagi_freecount--;
+	up_read(&mp->m_peraglock);
+#ifdef DEBUG
+	if (cur->bc_nlevels == 1) {
+		int	freecount = 0;
+
+		if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i)))
+			goto error0;
+		do {
+			if ((error = xfs_inobt_get_rec(cur, &rec.ir_startino,
+					&rec.ir_freecount, &rec.ir_free, &i, ARCH_NOCONVERT)))
+				goto error0;
+			XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+			freecount += rec.ir_freecount;
+			if ((error = xfs_inobt_increment(cur, 0, &i)))
+				goto error0;
+		} while (i == 1);
+		ASSERT(freecount == INT_GET(agi->agi_freecount, ARCH_CONVERT) ||
+		       XFS_FORCED_SHUTDOWN(mp));
+	}
+#endif
+	xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+	xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, -1);
+	*inop = ino;
+	return 0;
+error1:
+	xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
+error0:
+	xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
+	return error;
+}
+
+/*
+ * Free disk inode.  Carefully avoids touching the incore inode, all
+ * manipulations incore are the caller's responsibility.
+ * The on-disk inode is not changed by this operation, only the
+ * btree (free inode mask) is changed.
+ */
+int
+xfs_difree(
+	xfs_trans_t	*tp,		/* transaction pointer */
+	xfs_ino_t	inode,		/* inode to be freed */
+	xfs_bmap_free_t	*flist,		/* extents to free */
+	int		*delete,	/* set if inode cluster was deleted */
+	xfs_ino_t	*first_ino)	/* first inode in deleted cluster */
+{
+	/* REFERENCED */
+	xfs_agblock_t	agbno;	/* block number containing inode */
+	xfs_buf_t	*agbp;	/* buffer containing allocation group header */
+	xfs_agino_t	agino;	/* inode number relative to allocation group */
+	xfs_agnumber_t	agno;	/* allocation group number */
+	xfs_agi_t	*agi;	/* allocation group header */
+	xfs_btree_cur_t	*cur;	/* inode btree cursor */
+	int		error;	/* error return value */
+	int		i;	/* result code */
+	int		ilen;	/* inodes in an inode cluster */
+	xfs_mount_t	*mp;	/* mount structure for filesystem */
+	int		off;	/* offset of inode in inode chunk */
+	xfs_inobt_rec_t	rec;	/* btree record */
+
+	mp = tp->t_mountp;
+
+	/*
+	 * Break up inode number into its components.
+	 */
+	agno = XFS_INO_TO_AGNO(mp, inode);
+	if (agno >= mp->m_sb.sb_agcount)  {
+		cmn_err(CE_WARN,
+			"xfs_difree: agno >= mp->m_sb.sb_agcount (%d >= %d) on %s.  Returning EINVAL.",
+			agno, mp->m_sb.sb_agcount, mp->m_fsname);
+		ASSERT(0);
+		return XFS_ERROR(EINVAL);
+	}
+	agino = XFS_INO_TO_AGINO(mp, inode);
+	if (inode != XFS_AGINO_TO_INO(mp, agno, agino))  {
+		cmn_err(CE_WARN,
+			"xfs_difree: inode != XFS_AGINO_TO_INO() (%d != %d) on %s.  Returning EINVAL.",
+			inode, XFS_AGINO_TO_INO(mp, agno, agino), mp->m_fsname);
+		ASSERT(0);
+		return XFS_ERROR(EINVAL);
+	}
+	agbno = XFS_AGINO_TO_AGBNO(mp, agino);
+	if (agbno >= mp->m_sb.sb_agblocks)  {
+		cmn_err(CE_WARN,
+			"xfs_difree: agbno >= mp->m_sb.sb_agblocks (%d >= %d) on %s.  Returning EINVAL.",
+			agbno, mp->m_sb.sb_agblocks, mp->m_fsname);
+		ASSERT(0);
+		return XFS_ERROR(EINVAL);
+	}
+	/*
+	 * Get the allocation group header.
+	 */
+	down_read(&mp->m_peraglock);
+	error = xfs_ialloc_read_agi(mp, tp, agno, &agbp);
+	up_read(&mp->m_peraglock);
+	if (error) {
+		cmn_err(CE_WARN,
+			"xfs_difree: xfs_ialloc_read_agi() returned an error %d on %s.  Returning error.",
+			error, mp->m_fsname);
+		return error;
+	}
+	agi = XFS_BUF_TO_AGI(agbp);
+	ASSERT(INT_GET(agi->agi_magicnum, ARCH_CONVERT) == XFS_AGI_MAGIC);
+	ASSERT(agbno < INT_GET(agi->agi_length, ARCH_CONVERT));
+	/*
+	 * Initialize the cursor.
+	 */
+	cur = xfs_btree_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_INO,
+		(xfs_inode_t *)0, 0);
+#ifdef DEBUG
+	if (cur->bc_nlevels == 1) {
+		int freecount = 0;
+
+		if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i)))
+			goto error0;
+		do {
+			if ((error = xfs_inobt_get_rec(cur, &rec.ir_startino,
+					&rec.ir_freecount, &rec.ir_free, &i, ARCH_NOCONVERT)))
+				goto error0;
+			if (i) {
+				freecount += rec.ir_freecount;
+				if ((error = xfs_inobt_increment(cur, 0, &i)))
+					goto error0;
+			}
+		} while (i == 1);
+		ASSERT(freecount == INT_GET(agi->agi_freecount, ARCH_CONVERT) ||
+		       XFS_FORCED_SHUTDOWN(mp));
+	}
+#endif
+	/*
+	 * Look for the entry describing this inode.
+	 */
+	if ((error = xfs_inobt_lookup_le(cur, agino, 0, 0, &i))) {
+		cmn_err(CE_WARN,
+			"xfs_difree: xfs_inobt_lookup_le returned()  an error %d on %s.  Returning error.",
+			error, mp->m_fsname);
+		goto error0;
+	}
+	XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+	if ((error = xfs_inobt_get_rec(cur, &rec.ir_startino, &rec.ir_freecount,
+			&rec.ir_free, &i, ARCH_NOCONVERT))) {
+		cmn_err(CE_WARN,
+			"xfs_difree: xfs_inobt_get_rec()  returned an error %d on %s.  Returning error.",
+			error, mp->m_fsname);
+		goto error0;
+	}
+	XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+	/*
+	 * Get the offset in the inode chunk.
+	 */
+	off = agino - rec.ir_startino;
+	ASSERT(off >= 0 && off < XFS_INODES_PER_CHUNK);
+	ASSERT(!XFS_INOBT_IS_FREE(&rec, off, ARCH_NOCONVERT));
+	/*
+	 * Mark the inode free & increment the count.
+	 */
+	XFS_INOBT_SET_FREE(&rec, off, ARCH_NOCONVERT);
+	rec.ir_freecount++;
+
+	/*
+	 * When an inode cluster is free, it becomes elgible for removal
+	 */
+	if ((mp->m_flags & XFS_MOUNT_IDELETE) &&
+	    (rec.ir_freecount == XFS_IALLOC_INODES(mp))) {
+
+		*delete = 1;
+		*first_ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino);
+
+		/*
+		 * Remove the inode cluster from the AGI B+Tree, adjust the
+		 * AGI and Superblock inode counts, and mark the disk space
+		 * to be freed when the transaction is committed.
+		 */
+		ilen = XFS_IALLOC_INODES(mp);
+		INT_MOD(agi->agi_count, ARCH_CONVERT, -ilen);
+		INT_MOD(agi->agi_freecount, ARCH_CONVERT, -(ilen - 1));
+		xfs_ialloc_log_agi(tp, agbp, XFS_AGI_COUNT | XFS_AGI_FREECOUNT);
+		down_read(&mp->m_peraglock);
+		mp->m_perag[agno].pagi_freecount -= ilen - 1;
+		up_read(&mp->m_peraglock);
+		xfs_trans_mod_sb(tp, XFS_TRANS_SB_ICOUNT, -ilen);
+		xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, -(ilen - 1));
+
+		if ((error = xfs_inobt_delete(cur, &i))) {
+			cmn_err(CE_WARN, "xfs_difree: xfs_inobt_delete returned an error %d on %s.\n",
+				error, mp->m_fsname);
+			goto error0;
+		}
+
+		xfs_bmap_add_free(XFS_AGB_TO_FSB(mp,
+				agno, XFS_INO_TO_AGBNO(mp,rec.ir_startino)),
+				XFS_IALLOC_BLOCKS(mp), flist, mp);
+	} else {
+		*delete = 0;
+
+		if ((error = xfs_inobt_update(cur, rec.ir_startino, rec.ir_freecount, rec.ir_free))) {
+			cmn_err(CE_WARN,
+				"xfs_difree: xfs_inobt_update()  returned an error %d on %s.  Returning error.",
+				error, mp->m_fsname);
+			goto error0;
+		}
+		/* 
+		 * Change the inode free counts and log the ag/sb changes.
+		 */
+		INT_MOD(agi->agi_freecount, ARCH_CONVERT, 1);
+		xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT);
+		down_read(&mp->m_peraglock);
+		mp->m_perag[agno].pagi_freecount++;
+		up_read(&mp->m_peraglock);
+		xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, 1);
+	}
+
+#ifdef DEBUG
+	if (cur->bc_nlevels == 1) {
+		int freecount = 0;
+
+		if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i)))
+			goto error0;
+		do {
+			if ((error = xfs_inobt_get_rec(cur,
+					&rec.ir_startino,
+					&rec.ir_freecount,
+					&rec.ir_free, &i,
+					ARCH_NOCONVERT)))
+				goto error0;
+			if (i) {
+				freecount += rec.ir_freecount;
+				if ((error = xfs_inobt_increment(cur, 0, &i)))
+					goto error0;
+			}
+		} while (i == 1);
+		ASSERT(freecount == INT_GET(agi->agi_freecount, ARCH_CONVERT) ||
+		       XFS_FORCED_SHUTDOWN(mp));
+	}
+#endif
+	xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+	return 0;
+
+error0:
+	xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
+	return error;
+}
+
+/*
+ * Return the location of the inode in bno/off, for mapping it into a buffer.
+ */
+/*ARGSUSED*/
+int
+xfs_dilocate(
+	xfs_mount_t	*mp,	/* file system mount structure */
+	xfs_trans_t	*tp,	/* transaction pointer */
+	xfs_ino_t	ino,	/* inode to locate */
+	xfs_fsblock_t	*bno,	/* output: block containing inode */
+	int		*len,	/* output: num blocks in inode cluster */
+	int		*off,	/* output: index in block of inode */
+	uint		flags)	/* flags concerning inode lookup */
+{
+	xfs_agblock_t	agbno;	/* block number of inode in the alloc group */
+	xfs_buf_t	*agbp;	/* agi buffer */
+	xfs_agino_t	agino;	/* inode number within alloc group */
+	xfs_agnumber_t	agno;	/* allocation group number */
+	int		blks_per_cluster; /* num blocks per inode cluster */
+	xfs_agblock_t	chunk_agbno;	/* first block in inode chunk */
+	xfs_agino_t	chunk_agino;	/* first agino in inode chunk */
+	__int32_t	chunk_cnt;	/* count of free inodes in chunk */
+	xfs_inofree_t	chunk_free;	/* mask of free inodes in chunk */
+	xfs_agblock_t	cluster_agbno;	/* first block in inode cluster */
+	xfs_btree_cur_t	*cur;	/* inode btree cursor */
+	int		error;	/* error code */
+	int		i;	/* temp state */
+	int		offset;	/* index of inode in its buffer */
+	int		offset_agbno;	/* blks from chunk start to inode */
+
+	ASSERT(ino != NULLFSINO);
+	/*
+	 * Split up the inode number into its parts.
+	 */
+	agno = XFS_INO_TO_AGNO(mp, ino);
+	agino = XFS_INO_TO_AGINO(mp, ino);
+	agbno = XFS_AGINO_TO_AGBNO(mp, agino);
+	if (agno >= mp->m_sb.sb_agcount || agbno >= mp->m_sb.sb_agblocks ||
+	    ino != XFS_AGINO_TO_INO(mp, agno, agino)) {
+#ifdef DEBUG
+		if (agno >= mp->m_sb.sb_agcount) {
+			xfs_fs_cmn_err(CE_ALERT, mp,
+					"xfs_dilocate: agno (%d) >= "
+					"mp->m_sb.sb_agcount (%d)",
+					agno,  mp->m_sb.sb_agcount);
+		}
+		if (agbno >= mp->m_sb.sb_agblocks) {
+			xfs_fs_cmn_err(CE_ALERT, mp,
+					"xfs_dilocate: agbno (0x%llx) >= "
+					"mp->m_sb.sb_agblocks (0x%lx)",
+					(unsigned long long) agbno,
+					(unsigned long) mp->m_sb.sb_agblocks);
+		}
+		if (ino != XFS_AGINO_TO_INO(mp, agno, agino)) {
+			xfs_fs_cmn_err(CE_ALERT, mp,
+					"xfs_dilocate: ino (0x%llx) != "
+					"XFS_AGINO_TO_INO(mp, agno, agino) "
+					"(0x%llx)",
+					ino, XFS_AGINO_TO_INO(mp, agno, agino));
+		}
+#endif /* DEBUG */
+		return XFS_ERROR(EINVAL);
+	}
+	if ((mp->m_sb.sb_blocksize >= XFS_INODE_CLUSTER_SIZE(mp)) ||
+	    !(flags & XFS_IMAP_LOOKUP)) {
+		offset = XFS_INO_TO_OFFSET(mp, ino);
+		ASSERT(offset < mp->m_sb.sb_inopblock);
+		*bno = XFS_AGB_TO_FSB(mp, agno, agbno);
+		*off = offset;
+		*len = 1;
+		return 0;
+	}
+	blks_per_cluster = XFS_INODE_CLUSTER_SIZE(mp) >> mp->m_sb.sb_blocklog;
+	if (*bno != NULLFSBLOCK) {
+		offset = XFS_INO_TO_OFFSET(mp, ino);
+		ASSERT(offset < mp->m_sb.sb_inopblock);
+		cluster_agbno = XFS_FSB_TO_AGBNO(mp, *bno);
+		*off = ((agbno - cluster_agbno) * mp->m_sb.sb_inopblock) +
+			offset;
+		*len = blks_per_cluster;
+		return 0;
+	}
+	if (mp->m_inoalign_mask) {
+		offset_agbno = agbno & mp->m_inoalign_mask;
+		chunk_agbno = agbno - offset_agbno;
+	} else {
+		down_read(&mp->m_peraglock);
+		error = xfs_ialloc_read_agi(mp, tp, agno, &agbp);
+		up_read(&mp->m_peraglock);
+		if (error) {
+#ifdef DEBUG
+			xfs_fs_cmn_err(CE_ALERT, mp, "xfs_dilocate: "
+					"xfs_ialloc_read_agi() returned "
+					"error %d, agno %d",
+					error, agno);
+#endif /* DEBUG */
+			return error;
+		}
+		cur = xfs_btree_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_INO,
+			(xfs_inode_t *)0, 0);
+		if ((error = xfs_inobt_lookup_le(cur, agino, 0, 0, &i))) {
+#ifdef DEBUG
+			xfs_fs_cmn_err(CE_ALERT, mp, "xfs_dilocate: "
+					"xfs_inobt_lookup_le() failed");
+#endif /* DEBUG */
+			goto error0;
+		}
+		if ((error = xfs_inobt_get_rec(cur, &chunk_agino, &chunk_cnt,
+				&chunk_free, &i, ARCH_NOCONVERT))) {
+#ifdef DEBUG
+			xfs_fs_cmn_err(CE_ALERT, mp, "xfs_dilocate: "
+					"xfs_inobt_get_rec() failed");
+#endif /* DEBUG */
+			goto error0;
+		}
+		if (i == 0) {
+#ifdef DEBUG
+			xfs_fs_cmn_err(CE_ALERT, mp, "xfs_dilocate: "
+					"xfs_inobt_get_rec() failed");
+#endif /* DEBUG */
+			error = XFS_ERROR(EINVAL);
+		}
+		xfs_trans_brelse(tp, agbp);
+		xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+		if (error)
+			return error;
+		chunk_agbno = XFS_AGINO_TO_AGBNO(mp, chunk_agino);
+		offset_agbno = agbno - chunk_agbno;
+	}
+	ASSERT(agbno >= chunk_agbno);
+	cluster_agbno = chunk_agbno +
+		((offset_agbno / blks_per_cluster) * blks_per_cluster);
+	offset = ((agbno - cluster_agbno) * mp->m_sb.sb_inopblock) +
+		XFS_INO_TO_OFFSET(mp, ino);
+	*bno = XFS_AGB_TO_FSB(mp, agno, cluster_agbno);
+	*off = offset;
+	*len = blks_per_cluster;
+	return 0;
+error0:
+	xfs_trans_brelse(tp, agbp);
+	xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
+	return error;
+}
+
+/*
+ * Compute and fill in value of m_in_maxlevels.
+ */
+void
+xfs_ialloc_compute_maxlevels(
+	xfs_mount_t	*mp)		/* file system mount structure */
+{
+	int		level;
+	uint		maxblocks;
+	uint		maxleafents;
+	int		minleafrecs;
+	int		minnoderecs;
+
+	maxleafents = (1LL << XFS_INO_AGINO_BITS(mp)) >>
+		XFS_INODES_PER_CHUNK_LOG;
+	minleafrecs = mp->m_alloc_mnr[0];
+	minnoderecs = mp->m_alloc_mnr[1];
+	maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
+	for (level = 1; maxblocks > 1; level++)
+		maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
+	mp->m_in_maxlevels = level;
+}
+
+/*
+ * Log specified fields for the ag hdr (inode section)
+ */
+void
+xfs_ialloc_log_agi(
+	xfs_trans_t	*tp,		/* transaction pointer */
+	xfs_buf_t	*bp,		/* allocation group header buffer */
+	int		fields)		/* bitmask of fields to log */
+{
+	int			first;		/* first byte number */
+	int			last;		/* last byte number */
+	static const short	offsets[] = {	/* field starting offsets */
+					/* keep in sync with bit definitions */
+		offsetof(xfs_agi_t, agi_magicnum),
+		offsetof(xfs_agi_t, agi_versionnum),
+		offsetof(xfs_agi_t, agi_seqno),
+		offsetof(xfs_agi_t, agi_length),
+		offsetof(xfs_agi_t, agi_count),
+		offsetof(xfs_agi_t, agi_root),
+		offsetof(xfs_agi_t, agi_level),
+		offsetof(xfs_agi_t, agi_freecount),
+		offsetof(xfs_agi_t, agi_newino),
+		offsetof(xfs_agi_t, agi_dirino),
+		offsetof(xfs_agi_t, agi_unlinked),
+		sizeof(xfs_agi_t)
+	};
+#ifdef DEBUG
+	xfs_agi_t		*agi;	/* allocation group header */
+
+	agi = XFS_BUF_TO_AGI(bp);
+	ASSERT(INT_GET(agi->agi_magicnum, ARCH_CONVERT) == XFS_AGI_MAGIC);
+#endif
+	/*
+	 * Compute byte offsets for the first and last fields.
+	 */
+	xfs_btree_offsets(fields, offsets, XFS_AGI_NUM_BITS, &first, &last);
+	/*
+	 * Log the allocation group inode header buffer.
+	 */
+	xfs_trans_log_buf(tp, bp, first, last);
+}
+
+/*
+ * Read in the allocation group header (inode allocation section)
+ */
+int
+xfs_ialloc_read_agi(
+	xfs_mount_t	*mp,		/* file system mount structure */
+	xfs_trans_t	*tp,		/* transaction pointer */
+	xfs_agnumber_t	agno,		/* allocation group number */
+	xfs_buf_t	**bpp)		/* allocation group hdr buf */
+{
+	xfs_agi_t	*agi;		/* allocation group header */
+	int		agi_ok;		/* agi is consistent */
+	xfs_buf_t	*bp;		/* allocation group hdr buf */
+	xfs_perag_t	*pag;		/* per allocation group data */
+	int		error;
+
+	ASSERT(agno != NULLAGNUMBER);
+	error = xfs_trans_read_buf(
+			mp, tp, mp->m_ddev_targp,
+			XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
+			XFS_FSS_TO_BB(mp, 1), 0, &bp);
+	if (error)
+		return error;
+	ASSERT(bp && !XFS_BUF_GETERROR(bp));
+
+	/*
+	 * Validate the magic number of the agi block.
+	 */
+	agi = XFS_BUF_TO_AGI(bp);
+	agi_ok =
+		INT_GET(agi->agi_magicnum, ARCH_CONVERT) == XFS_AGI_MAGIC &&
+		XFS_AGI_GOOD_VERSION(
+			INT_GET(agi->agi_versionnum, ARCH_CONVERT));
+	if (unlikely(XFS_TEST_ERROR(!agi_ok, mp, XFS_ERRTAG_IALLOC_READ_AGI,
+			XFS_RANDOM_IALLOC_READ_AGI))) {
+		XFS_CORRUPTION_ERROR("xfs_ialloc_read_agi", XFS_ERRLEVEL_LOW,
+				     mp, agi);
+		xfs_trans_brelse(tp, bp);
+		return XFS_ERROR(EFSCORRUPTED);
+	}
+	pag = &mp->m_perag[agno];
+	if (!pag->pagi_init) {
+		pag->pagi_freecount = INT_GET(agi->agi_freecount, ARCH_CONVERT);
+		pag->pagi_init = 1;
+	} else {
+		/*
+		 * It's possible for these to be out of sync if
+		 * we are in the middle of a forced shutdown.
+		 */
+		ASSERT(pag->pagi_freecount ==
+				INT_GET(agi->agi_freecount, ARCH_CONVERT)
+			|| XFS_FORCED_SHUTDOWN(mp));
+	}
+
+#ifdef DEBUG
+	{
+		int	i;
+
+		for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++)
+			ASSERT(!INT_ISZERO(agi->agi_unlinked[i], ARCH_CONVERT));
+	}
+#endif
+
+	XFS_BUF_SET_VTYPE_REF(bp, B_FS_AGI, XFS_AGI_REF);
+	*bpp = bp;
+	return 0;
+}
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)