fs/xfs/libxfs/xfs_ialloc_btree.c - kernel/quantenna - Git at Google

 /*
  * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
  * All Rights Reserved.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms 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.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write the Free Software Foundation,
  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
 #include "xfs.h"
 #include "xfs_fs.h"
 #include "xfs_shared.h"
 #include "xfs_format.h"
 #include "xfs_log_format.h"
 #include "xfs_trans_resv.h"
 #include "xfs_bit.h"
 #include "xfs_mount.h"
 #include "xfs_inode.h"
 #include "xfs_btree.h"
 #include "xfs_ialloc.h"
 #include "xfs_ialloc_btree.h"
 #include "xfs_alloc.h"
 #include "xfs_error.h"
 #include "xfs_trace.h"
 #include "xfs_cksum.h"
 #include "xfs_trans.h"


 STATIC int
 xfs_inobt_get_minrecs(
 	struct xfs_btree_cur	*cur,
 	int			level)
 {
 	return cur->bc_mp->m_inobt_mnr[level != 0];
 }

 STATIC struct xfs_btree_cur *
 xfs_inobt_dup_cursor(
 	struct xfs_btree_cur	*cur)
 {
 	return xfs_inobt_init_cursor(cur->bc_mp, cur->bc_tp,
 			cur->bc_private.a.agbp, cur->bc_private.a.agno,
 			cur->bc_btnum);
 }

 STATIC void
 xfs_inobt_set_root(
 	struct xfs_btree_cur	*cur,
 	union xfs_btree_ptr	*nptr,
 	int			inc)	/* level change */
 {
 	struct xfs_buf		*agbp = cur->bc_private.a.agbp;
 	struct xfs_agi		*agi = XFS_BUF_TO_AGI(agbp);

 	agi->agi_root = nptr->s;
 	be32_add_cpu(&agi->agi_level, inc);
 	xfs_ialloc_log_agi(cur->bc_tp, agbp, XFS_AGI_ROOT | XFS_AGI_LEVEL);
 }

 STATIC void
 xfs_finobt_set_root(
 	struct xfs_btree_cur	*cur,
 	union xfs_btree_ptr	*nptr,
 	int			inc)	/* level change */
 {
 	struct xfs_buf		*agbp = cur->bc_private.a.agbp;
 	struct xfs_agi		*agi = XFS_BUF_TO_AGI(agbp);

 	agi->agi_free_root = nptr->s;
 	be32_add_cpu(&agi->agi_free_level, inc);
 	xfs_ialloc_log_agi(cur->bc_tp, agbp,
 			   XFS_AGI_FREE_ROOT | XFS_AGI_FREE_LEVEL);
 }

 STATIC int
 xfs_inobt_alloc_block(
 	struct xfs_btree_cur	*cur,
 	union xfs_btree_ptr	*start,
 	union xfs_btree_ptr	*new,
 	int			*stat)
 {
 	xfs_alloc_arg_t		args;		/* block allocation args */
 	int			error;		/* error return value */
 	xfs_agblock_t		sbno = be32_to_cpu(start->s);

 	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);

 	memset(&args, 0, sizeof(args));
 	args.tp = cur->bc_tp;
 	args.mp = cur->bc_mp;
 	args.fsbno = XFS_AGB_TO_FSB(args.mp, cur->bc_private.a.agno, sbno);
 	args.minlen = 1;
 	args.maxlen = 1;
 	args.prod = 1;
 	args.type = XFS_ALLOCTYPE_NEAR_BNO;

 	error = xfs_alloc_vextent(&args);
 	if (error) {
 		XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
 		return error;
 	}
 	if (args.fsbno == NULLFSBLOCK) {
 		XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
 		*stat = 0;
 		return 0;
 	}
 	ASSERT(args.len == 1);
 	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);

 	new->s = cpu_to_be32(XFS_FSB_TO_AGBNO(args.mp, args.fsbno));
 	*stat = 1;
 	return 0;
 }

 STATIC int
 xfs_inobt_free_block(
 	struct xfs_btree_cur	*cur,
 	struct xfs_buf		*bp)
 {
 	return xfs_free_extent(cur->bc_tp,
 			XFS_DADDR_TO_FSB(cur->bc_mp, XFS_BUF_ADDR(bp)), 1);
 }

 STATIC int
 xfs_inobt_get_maxrecs(
 	struct xfs_btree_cur	*cur,
 	int			level)
 {
 	return cur->bc_mp->m_inobt_mxr[level != 0];
 }

 STATIC void
 xfs_inobt_init_key_from_rec(
 	union xfs_btree_key	*key,
 	union xfs_btree_rec	*rec)
 {
 	key->inobt.ir_startino = rec->inobt.ir_startino;
 }

 STATIC void
 xfs_inobt_init_rec_from_key(
 	union xfs_btree_key	*key,
 	union xfs_btree_rec	*rec)
 {
 	rec->inobt.ir_startino = key->inobt.ir_startino;
 }

 STATIC void
 xfs_inobt_init_rec_from_cur(
 	struct xfs_btree_cur	*cur,
 	union xfs_btree_rec	*rec)
 {
 	rec->inobt.ir_startino = cpu_to_be32(cur->bc_rec.i.ir_startino);
 	if (xfs_sb_version_hassparseinodes(&cur->bc_mp->m_sb)) {
 		rec->inobt.ir_u.sp.ir_holemask =
 					cpu_to_be16(cur->bc_rec.i.ir_holemask);
 		rec->inobt.ir_u.sp.ir_count = cur->bc_rec.i.ir_count;
 		rec->inobt.ir_u.sp.ir_freecount = cur->bc_rec.i.ir_freecount;
 	} else {
 		/* ir_holemask/ir_count not supported on-disk */
 		rec->inobt.ir_u.f.ir_freecount =
 					cpu_to_be32(cur->bc_rec.i.ir_freecount);
 	}
 	rec->inobt.ir_free = cpu_to_be64(cur->bc_rec.i.ir_free);
 }

 /*
  * initial value of ptr for lookup
  */
 STATIC void
 xfs_inobt_init_ptr_from_cur(
 	struct xfs_btree_cur	*cur,
 	union xfs_btree_ptr	*ptr)
 {
 	struct xfs_agi		*agi = XFS_BUF_TO_AGI(cur->bc_private.a.agbp);

 	ASSERT(cur->bc_private.a.agno == be32_to_cpu(agi->agi_seqno));

 	ptr->s = agi->agi_root;
 }

 STATIC void
 xfs_finobt_init_ptr_from_cur(
 	struct xfs_btree_cur	*cur,
 	union xfs_btree_ptr	*ptr)
 {
 	struct xfs_agi		*agi = XFS_BUF_TO_AGI(cur->bc_private.a.agbp);

 	ASSERT(cur->bc_private.a.agno == be32_to_cpu(agi->agi_seqno));
 	ptr->s = agi->agi_free_root;
 }

 STATIC __int64_t
 xfs_inobt_key_diff(
 	struct xfs_btree_cur	*cur,
 	union xfs_btree_key	*key)
 {
 	return (__int64_t)be32_to_cpu(key->inobt.ir_startino) -
 			  cur->bc_rec.i.ir_startino;
 }

 static int
 xfs_inobt_verify(
 	struct xfs_buf		*bp)
 {
 	struct xfs_mount	*mp = bp->b_target->bt_mount;
 	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
 	unsigned int		level;

 	/*
 	 * During growfs operations, we can't verify the exact owner as the
 	 * perag is not fully initialised and hence not attached to the buffer.
 	 *
 	 * Similarly, during log recovery we will have a perag structure
 	 * attached, but the agi information will not yet have been initialised
 	 * from the on disk AGI. We don't currently use any of this information,
 	 * but beware of the landmine (i.e. need to check pag->pagi_init) if we
 	 * ever do.
 	 */
 	switch (block->bb_magic) {
 	case cpu_to_be32(XFS_IBT_CRC_MAGIC):
 	case cpu_to_be32(XFS_FIBT_CRC_MAGIC):
 		if (!xfs_btree_sblock_v5hdr_verify(bp))
 			return false;
 		/* fall through */
 	case cpu_to_be32(XFS_IBT_MAGIC):
 	case cpu_to_be32(XFS_FIBT_MAGIC):
 		break;
 	default:
 		return 0;
 	}

 	/* level verification */
 	level = be16_to_cpu(block->bb_level);
 	if (level >= mp->m_in_maxlevels)
 		return false;

 	return xfs_btree_sblock_verify(bp, mp->m_inobt_mxr[level != 0]);
 }

 static void
 xfs_inobt_read_verify(
 	struct xfs_buf	*bp)
 {
 	if (!xfs_btree_sblock_verify_crc(bp))
 		xfs_buf_ioerror(bp, -EFSBADCRC);
 	else if (!xfs_inobt_verify(bp))
 		xfs_buf_ioerror(bp, -EFSCORRUPTED);

 	if (bp->b_error) {
 		trace_xfs_btree_corrupt(bp, _RET_IP_);
 		xfs_verifier_error(bp);
 	}
 }

 static void
 xfs_inobt_write_verify(
 	struct xfs_buf	*bp)
 {
 	if (!xfs_inobt_verify(bp)) {
 		trace_xfs_btree_corrupt(bp, _RET_IP_);
 		xfs_buf_ioerror(bp, -EFSCORRUPTED);
 		xfs_verifier_error(bp);
 		return;
 	}
 	xfs_btree_sblock_calc_crc(bp);

 }

 const struct xfs_buf_ops xfs_inobt_buf_ops = {
 	.name = "xfs_inobt",
 	.verify_read = xfs_inobt_read_verify,
 	.verify_write = xfs_inobt_write_verify,
 };

 #if defined(DEBUG) || defined(XFS_WARN)
 STATIC int
 xfs_inobt_keys_inorder(
 	struct xfs_btree_cur	*cur,
 	union xfs_btree_key	*k1,
 	union xfs_btree_key	*k2)
 {
 	return be32_to_cpu(k1->inobt.ir_startino) <
 		be32_to_cpu(k2->inobt.ir_startino);
 }

 STATIC int
 xfs_inobt_recs_inorder(
 	struct xfs_btree_cur	*cur,
 	union xfs_btree_rec	*r1,
 	union xfs_btree_rec	*r2)
 {
 	return be32_to_cpu(r1->inobt.ir_startino) + XFS_INODES_PER_CHUNK <=
 		be32_to_cpu(r2->inobt.ir_startino);
 }
 #endif	/* DEBUG */

 static const struct xfs_btree_ops xfs_inobt_ops = {
 	.rec_len		= sizeof(xfs_inobt_rec_t),
 	.key_len		= sizeof(xfs_inobt_key_t),

 	.dup_cursor		= xfs_inobt_dup_cursor,
 	.set_root		= xfs_inobt_set_root,
 	.alloc_block		= xfs_inobt_alloc_block,
 	.free_block		= xfs_inobt_free_block,
 	.get_minrecs		= xfs_inobt_get_minrecs,
 	.get_maxrecs		= xfs_inobt_get_maxrecs,
 	.init_key_from_rec	= xfs_inobt_init_key_from_rec,
 	.init_rec_from_key	= xfs_inobt_init_rec_from_key,
 	.init_rec_from_cur	= xfs_inobt_init_rec_from_cur,
 	.init_ptr_from_cur	= xfs_inobt_init_ptr_from_cur,
 	.key_diff		= xfs_inobt_key_diff,
 	.buf_ops		= &xfs_inobt_buf_ops,
 #if defined(DEBUG) || defined(XFS_WARN)
 	.keys_inorder		= xfs_inobt_keys_inorder,
 	.recs_inorder		= xfs_inobt_recs_inorder,
 #endif
 };

 static const struct xfs_btree_ops xfs_finobt_ops = {
 	.rec_len		= sizeof(xfs_inobt_rec_t),
 	.key_len		= sizeof(xfs_inobt_key_t),

 	.dup_cursor		= xfs_inobt_dup_cursor,
 	.set_root		= xfs_finobt_set_root,
 	.alloc_block		= xfs_inobt_alloc_block,
 	.free_block		= xfs_inobt_free_block,
 	.get_minrecs		= xfs_inobt_get_minrecs,
 	.get_maxrecs		= xfs_inobt_get_maxrecs,
 	.init_key_from_rec	= xfs_inobt_init_key_from_rec,
 	.init_rec_from_key	= xfs_inobt_init_rec_from_key,
 	.init_rec_from_cur	= xfs_inobt_init_rec_from_cur,
 	.init_ptr_from_cur	= xfs_finobt_init_ptr_from_cur,
 	.key_diff		= xfs_inobt_key_diff,
 	.buf_ops		= &xfs_inobt_buf_ops,
 #if defined(DEBUG) || defined(XFS_WARN)
 	.keys_inorder		= xfs_inobt_keys_inorder,
 	.recs_inorder		= xfs_inobt_recs_inorder,
 #endif
 };

 /*
  * Allocate a new inode btree cursor.
  */
 struct xfs_btree_cur *				/* new inode btree cursor */
 xfs_inobt_init_cursor(
 	struct xfs_mount	*mp,		/* file system mount point */
 	struct xfs_trans	*tp,		/* transaction pointer */
 	struct xfs_buf		*agbp,		/* buffer for agi structure */
 	xfs_agnumber_t		agno,		/* allocation group number */
 	xfs_btnum_t		btnum)		/* ialloc or free ino btree */
 {
 	struct xfs_agi		*agi = XFS_BUF_TO_AGI(agbp);
 	struct xfs_btree_cur	*cur;

 	cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_SLEEP);

 	cur->bc_tp = tp;
 	cur->bc_mp = mp;
 	cur->bc_btnum = btnum;
 	if (btnum == XFS_BTNUM_INO) {
 		cur->bc_nlevels = be32_to_cpu(agi->agi_level);
 		cur->bc_ops = &xfs_inobt_ops;
 	} else {
 		cur->bc_nlevels = be32_to_cpu(agi->agi_free_level);
 		cur->bc_ops = &xfs_finobt_ops;
 	}

 	cur->bc_blocklog = mp->m_sb.sb_blocklog;

 	if (xfs_sb_version_hascrc(&mp->m_sb))
 		cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;

 	cur->bc_private.a.agbp = agbp;
 	cur->bc_private.a.agno = agno;

 	return cur;
 }

 /*
  * Calculate number of records in an inobt btree block.
  */
 int
 xfs_inobt_maxrecs(
 	struct xfs_mount	*mp,
 	int			blocklen,
 	int			leaf)
 {
 	blocklen -= XFS_INOBT_BLOCK_LEN(mp);

 	if (leaf)
 		return blocklen / sizeof(xfs_inobt_rec_t);
 	return blocklen / (sizeof(xfs_inobt_key_t) + sizeof(xfs_inobt_ptr_t));
 }

 /*
  * Convert the inode record holemask to an inode allocation bitmap. The inode
  * allocation bitmap is inode granularity and specifies whether an inode is
  * physically allocated on disk (not whether the inode is considered allocated
  * or free by the fs).
  *
  * A bit value of 1 means the inode is allocated, a value of 0 means it is free.
  */
 uint64_t
 xfs_inobt_irec_to_allocmask(
 	struct xfs_inobt_rec_incore	*rec)
 {
 	uint64_t			bitmap = 0;
 	uint64_t			inodespbit;
 	int				nextbit;
 	uint				allocbitmap;

 	/*
 	 * The holemask has 16-bits for a 64 inode record. Therefore each
 	 * holemask bit represents multiple inodes. Create a mask of bits to set
 	 * in the allocmask for each holemask bit.
 	 */
 	inodespbit = (1 << XFS_INODES_PER_HOLEMASK_BIT) - 1;

 	/*
 	 * Allocated inodes are represented by 0 bits in holemask. Invert the 0
 	 * bits to 1 and convert to a uint so we can use xfs_next_bit(). Mask
 	 * anything beyond the 16 holemask bits since this casts to a larger
 	 * type.
 	 */
 	allocbitmap = ~rec->ir_holemask & ((1 << XFS_INOBT_HOLEMASK_BITS) - 1);

 	/*
 	 * allocbitmap is the inverted holemask so every set bit represents
 	 * allocated inodes. To expand from 16-bit holemask granularity to
 	 * 64-bit (e.g., bit-per-inode), set inodespbit bits in the target
 	 * bitmap for every holemask bit.
 	 */
 	nextbit = xfs_next_bit(&allocbitmap, 1, 0);
 	while (nextbit != -1) {
 		ASSERT(nextbit < (sizeof(rec->ir_holemask) * NBBY));

 		bitmap |= (inodespbit <<
 			   (nextbit * XFS_INODES_PER_HOLEMASK_BIT));

 		nextbit = xfs_next_bit(&allocbitmap, 1, nextbit + 1);
 	}

 	return bitmap;
 }

 #if defined(DEBUG) || defined(XFS_WARN)
 /*
  * Verify that an in-core inode record has a valid inode count.
  */
 int
 xfs_inobt_rec_check_count(
 	struct xfs_mount		*mp,
 	struct xfs_inobt_rec_incore	*rec)
 {
 	int				inocount = 0;
 	int				nextbit = 0;
 	uint64_t			allocbmap;
 	int				wordsz;

 	wordsz = sizeof(allocbmap) / sizeof(unsigned int);
 	allocbmap = xfs_inobt_irec_to_allocmask(rec);

 	nextbit = xfs_next_bit((uint *) &allocbmap, wordsz, nextbit);
 	while (nextbit != -1) {
 		inocount++;
 		nextbit = xfs_next_bit((uint *) &allocbmap, wordsz,
 				       nextbit + 1);
 	}

 	if (inocount != rec->ir_count)
 		return -EFSCORRUPTED;

 	return 0;
 }
 #endif	/* DEBUG */
	/*
	* Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
	* All Rights Reserved.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms 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. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	*/
	#include "xfs.h"
	#include "xfs_fs.h"
	#include "xfs_shared.h"
	#include "xfs_format.h"
	#include "xfs_log_format.h"
	#include "xfs_trans_resv.h"
	#include "xfs_bit.h"
	#include "xfs_mount.h"
	#include "xfs_inode.h"
	#include "xfs_btree.h"
	#include "xfs_ialloc.h"
	#include "xfs_ialloc_btree.h"
	#include "xfs_alloc.h"
	#include "xfs_error.h"
	#include "xfs_trace.h"
	#include "xfs_cksum.h"
	#include "xfs_trans.h"


	STATIC int
	xfs_inobt_get_minrecs(
	struct xfs_btree_cur *cur,
	int level)
	{
	return cur->bc_mp->m_inobt_mnr[level != 0];
	}

	STATIC struct xfs_btree_cur *
	xfs_inobt_dup_cursor(
	struct xfs_btree_cur *cur)
	{
	return xfs_inobt_init_cursor(cur->bc_mp, cur->bc_tp,
	cur->bc_private.a.agbp, cur->bc_private.a.agno,
	cur->bc_btnum);
	}

	STATIC void
	xfs_inobt_set_root(
	struct xfs_btree_cur *cur,
	union xfs_btree_ptr *nptr,
	int inc) /* level change */
	{
	struct xfs_buf *agbp = cur->bc_private.a.agbp;
	struct xfs_agi *agi = XFS_BUF_TO_AGI(agbp);

	agi->agi_root = nptr->s;
	be32_add_cpu(&agi->agi_level, inc);
	xfs_ialloc_log_agi(cur->bc_tp, agbp, XFS_AGI_ROOT \| XFS_AGI_LEVEL);
	}

	STATIC void
	xfs_finobt_set_root(
	struct xfs_btree_cur *cur,
	union xfs_btree_ptr *nptr,
	int inc) /* level change */
	{
	struct xfs_buf *agbp = cur->bc_private.a.agbp;
	struct xfs_agi *agi = XFS_BUF_TO_AGI(agbp);

	agi->agi_free_root = nptr->s;
	be32_add_cpu(&agi->agi_free_level, inc);
	xfs_ialloc_log_agi(cur->bc_tp, agbp,
	XFS_AGI_FREE_ROOT \| XFS_AGI_FREE_LEVEL);
	}

	STATIC int
	xfs_inobt_alloc_block(
	struct xfs_btree_cur *cur,
	union xfs_btree_ptr *start,
	union xfs_btree_ptr *new,
	int *stat)
	{
	xfs_alloc_arg_t args; /* block allocation args */
	int error; /* error return value */
	xfs_agblock_t sbno = be32_to_cpu(start->s);

	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);

	memset(&args, 0, sizeof(args));
	args.tp = cur->bc_tp;
	args.mp = cur->bc_mp;
	args.fsbno = XFS_AGB_TO_FSB(args.mp, cur->bc_private.a.agno, sbno);
	args.minlen = 1;
	args.maxlen = 1;
	args.prod = 1;
	args.type = XFS_ALLOCTYPE_NEAR_BNO;

	error = xfs_alloc_vextent(&args);
	if (error) {
	XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
	return error;
	}
	if (args.fsbno == NULLFSBLOCK) {
	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
	*stat = 0;
	return 0;
	}
	ASSERT(args.len == 1);
	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);

	new->s = cpu_to_be32(XFS_FSB_TO_AGBNO(args.mp, args.fsbno));
	*stat = 1;
	return 0;
	}

	STATIC int
	xfs_inobt_free_block(
	struct xfs_btree_cur *cur,
	struct xfs_buf *bp)
	{
	return xfs_free_extent(cur->bc_tp,
	XFS_DADDR_TO_FSB(cur->bc_mp, XFS_BUF_ADDR(bp)), 1);
	}

	STATIC int
	xfs_inobt_get_maxrecs(
	struct xfs_btree_cur *cur,
	int level)
	{
	return cur->bc_mp->m_inobt_mxr[level != 0];
	}

	STATIC void
	xfs_inobt_init_key_from_rec(
	union xfs_btree_key *key,
	union xfs_btree_rec *rec)
	{
	key->inobt.ir_startino = rec->inobt.ir_startino;
	}

	STATIC void
	xfs_inobt_init_rec_from_key(
	union xfs_btree_key *key,
	union xfs_btree_rec *rec)
	{
	rec->inobt.ir_startino = key->inobt.ir_startino;
	}

	STATIC void
	xfs_inobt_init_rec_from_cur(
	struct xfs_btree_cur *cur,
	union xfs_btree_rec *rec)
	{
	rec->inobt.ir_startino = cpu_to_be32(cur->bc_rec.i.ir_startino);
	if (xfs_sb_version_hassparseinodes(&cur->bc_mp->m_sb)) {
	rec->inobt.ir_u.sp.ir_holemask =
	cpu_to_be16(cur->bc_rec.i.ir_holemask);
	rec->inobt.ir_u.sp.ir_count = cur->bc_rec.i.ir_count;
	rec->inobt.ir_u.sp.ir_freecount = cur->bc_rec.i.ir_freecount;
	} else {
	/* ir_holemask/ir_count not supported on-disk */
	rec->inobt.ir_u.f.ir_freecount =
	cpu_to_be32(cur->bc_rec.i.ir_freecount);
	}
	rec->inobt.ir_free = cpu_to_be64(cur->bc_rec.i.ir_free);
	}

	/*
	* initial value of ptr for lookup
	*/
	STATIC void
	xfs_inobt_init_ptr_from_cur(
	struct xfs_btree_cur *cur,
	union xfs_btree_ptr *ptr)
	{
	struct xfs_agi *agi = XFS_BUF_TO_AGI(cur->bc_private.a.agbp);

	ASSERT(cur->bc_private.a.agno == be32_to_cpu(agi->agi_seqno));

	ptr->s = agi->agi_root;
	}

	STATIC void
	xfs_finobt_init_ptr_from_cur(
	struct xfs_btree_cur *cur,
	union xfs_btree_ptr *ptr)
	{
	struct xfs_agi *agi = XFS_BUF_TO_AGI(cur->bc_private.a.agbp);

	ASSERT(cur->bc_private.a.agno == be32_to_cpu(agi->agi_seqno));
	ptr->s = agi->agi_free_root;
	}

	STATIC __int64_t
	xfs_inobt_key_diff(
	struct xfs_btree_cur *cur,
	union xfs_btree_key *key)
	{
	return (__int64_t)be32_to_cpu(key->inobt.ir_startino) -
	cur->bc_rec.i.ir_startino;
	}

	static int
	xfs_inobt_verify(
	struct xfs_buf *bp)
	{
	struct xfs_mount *mp = bp->b_target->bt_mount;
	struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
	unsigned int level;

	/*
	* During growfs operations, we can't verify the exact owner as the
	* perag is not fully initialised and hence not attached to the buffer.
	*
	* Similarly, during log recovery we will have a perag structure
	* attached, but the agi information will not yet have been initialised
	* from the on disk AGI. We don't currently use any of this information,
	* but beware of the landmine (i.e. need to check pag->pagi_init) if we
	* ever do.
	*/
	switch (block->bb_magic) {
	case cpu_to_be32(XFS_IBT_CRC_MAGIC):
	case cpu_to_be32(XFS_FIBT_CRC_MAGIC):
	if (!xfs_btree_sblock_v5hdr_verify(bp))
	return false;
	/* fall through */
	case cpu_to_be32(XFS_IBT_MAGIC):
	case cpu_to_be32(XFS_FIBT_MAGIC):
	break;
	default:
	return 0;
	}

	/* level verification */
	level = be16_to_cpu(block->bb_level);
	if (level >= mp->m_in_maxlevels)
	return false;

	return xfs_btree_sblock_verify(bp, mp->m_inobt_mxr[level != 0]);
	}

	static void
	xfs_inobt_read_verify(
	struct xfs_buf *bp)
	{
	if (!xfs_btree_sblock_verify_crc(bp))
	xfs_buf_ioerror(bp, -EFSBADCRC);
	else if (!xfs_inobt_verify(bp))
	xfs_buf_ioerror(bp, -EFSCORRUPTED);

	if (bp->b_error) {
	trace_xfs_btree_corrupt(bp, _RET_IP_);
	xfs_verifier_error(bp);
	}
	}

	static void
	xfs_inobt_write_verify(
	struct xfs_buf *bp)
	{
	if (!xfs_inobt_verify(bp)) {
	trace_xfs_btree_corrupt(bp, _RET_IP_);
	xfs_buf_ioerror(bp, -EFSCORRUPTED);
	xfs_verifier_error(bp);
	return;
	}
	xfs_btree_sblock_calc_crc(bp);

	}

	const struct xfs_buf_ops xfs_inobt_buf_ops = {
	.name = "xfs_inobt",
	.verify_read = xfs_inobt_read_verify,
	.verify_write = xfs_inobt_write_verify,
	};

	#if defined(DEBUG) \|\| defined(XFS_WARN)
	STATIC int
	xfs_inobt_keys_inorder(
	struct xfs_btree_cur *cur,
	union xfs_btree_key *k1,
	union xfs_btree_key *k2)
	{
	return be32_to_cpu(k1->inobt.ir_startino) <
	be32_to_cpu(k2->inobt.ir_startino);
	}

	STATIC int
	xfs_inobt_recs_inorder(
	struct xfs_btree_cur *cur,
	union xfs_btree_rec *r1,
	union xfs_btree_rec *r2)
	{
	return be32_to_cpu(r1->inobt.ir_startino) + XFS_INODES_PER_CHUNK <=
	be32_to_cpu(r2->inobt.ir_startino);
	}
	#endif /* DEBUG */

	static const struct xfs_btree_ops xfs_inobt_ops = {
	.rec_len = sizeof(xfs_inobt_rec_t),
	.key_len = sizeof(xfs_inobt_key_t),

	.dup_cursor = xfs_inobt_dup_cursor,
	.set_root = xfs_inobt_set_root,
	.alloc_block = xfs_inobt_alloc_block,
	.free_block = xfs_inobt_free_block,
	.get_minrecs = xfs_inobt_get_minrecs,
	.get_maxrecs = xfs_inobt_get_maxrecs,
	.init_key_from_rec = xfs_inobt_init_key_from_rec,
	.init_rec_from_key = xfs_inobt_init_rec_from_key,
	.init_rec_from_cur = xfs_inobt_init_rec_from_cur,
	.init_ptr_from_cur = xfs_inobt_init_ptr_from_cur,
	.key_diff = xfs_inobt_key_diff,
	.buf_ops = &xfs_inobt_buf_ops,
	#if defined(DEBUG) \|\| defined(XFS_WARN)
	.keys_inorder = xfs_inobt_keys_inorder,
	.recs_inorder = xfs_inobt_recs_inorder,
	#endif
	};

	static const struct xfs_btree_ops xfs_finobt_ops = {
	.rec_len = sizeof(xfs_inobt_rec_t),
	.key_len = sizeof(xfs_inobt_key_t),

	.dup_cursor = xfs_inobt_dup_cursor,
	.set_root = xfs_finobt_set_root,
	.alloc_block = xfs_inobt_alloc_block,
	.free_block = xfs_inobt_free_block,
	.get_minrecs = xfs_inobt_get_minrecs,
	.get_maxrecs = xfs_inobt_get_maxrecs,
	.init_key_from_rec = xfs_inobt_init_key_from_rec,
	.init_rec_from_key = xfs_inobt_init_rec_from_key,
	.init_rec_from_cur = xfs_inobt_init_rec_from_cur,
	.init_ptr_from_cur = xfs_finobt_init_ptr_from_cur,
	.key_diff = xfs_inobt_key_diff,
	.buf_ops = &xfs_inobt_buf_ops,
	#if defined(DEBUG) \|\| defined(XFS_WARN)
	.keys_inorder = xfs_inobt_keys_inorder,
	.recs_inorder = xfs_inobt_recs_inorder,
	#endif
	};

	/*
	* Allocate a new inode btree cursor.
	*/
	struct xfs_btree_cur * /* new inode btree cursor */
	xfs_inobt_init_cursor(
	struct xfs_mount mp, / file system mount point */
	struct xfs_trans tp, / transaction pointer */
	struct xfs_buf agbp, / buffer for agi structure */
	xfs_agnumber_t agno, /* allocation group number */
	xfs_btnum_t btnum) /* ialloc or free ino btree */
	{
	struct xfs_agi *agi = XFS_BUF_TO_AGI(agbp);
	struct xfs_btree_cur *cur;

	cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_SLEEP);

	cur->bc_tp = tp;
	cur->bc_mp = mp;
	cur->bc_btnum = btnum;
	if (btnum == XFS_BTNUM_INO) {
	cur->bc_nlevels = be32_to_cpu(agi->agi_level);
	cur->bc_ops = &xfs_inobt_ops;
	} else {
	cur->bc_nlevels = be32_to_cpu(agi->agi_free_level);
	cur->bc_ops = &xfs_finobt_ops;
	}

	cur->bc_blocklog = mp->m_sb.sb_blocklog;

	if (xfs_sb_version_hascrc(&mp->m_sb))
	cur->bc_flags \|= XFS_BTREE_CRC_BLOCKS;

	cur->bc_private.a.agbp = agbp;
	cur->bc_private.a.agno = agno;

	return cur;
	}

	/*
	* Calculate number of records in an inobt btree block.
	*/
	int
	xfs_inobt_maxrecs(
	struct xfs_mount *mp,
	int blocklen,
	int leaf)
	{
	blocklen -= XFS_INOBT_BLOCK_LEN(mp);

	if (leaf)
	return blocklen / sizeof(xfs_inobt_rec_t);
	return blocklen / (sizeof(xfs_inobt_key_t) + sizeof(xfs_inobt_ptr_t));
	}

	/*
	* Convert the inode record holemask to an inode allocation bitmap. The inode
	* allocation bitmap is inode granularity and specifies whether an inode is
	* physically allocated on disk (not whether the inode is considered allocated
	* or free by the fs).
	*
	* A bit value of 1 means the inode is allocated, a value of 0 means it is free.
	*/
	uint64_t
	xfs_inobt_irec_to_allocmask(
	struct xfs_inobt_rec_incore *rec)
	{
	uint64_t bitmap = 0;
	uint64_t inodespbit;
	int nextbit;
	uint allocbitmap;

	/*
	* The holemask has 16-bits for a 64 inode record. Therefore each
	* holemask bit represents multiple inodes. Create a mask of bits to set
	* in the allocmask for each holemask bit.
	*/
	inodespbit = (1 << XFS_INODES_PER_HOLEMASK_BIT) - 1;

	/*
	* Allocated inodes are represented by 0 bits in holemask. Invert the 0
	* bits to 1 and convert to a uint so we can use xfs_next_bit(). Mask
	* anything beyond the 16 holemask bits since this casts to a larger
	* type.
	*/
	allocbitmap = ~rec->ir_holemask & ((1 << XFS_INOBT_HOLEMASK_BITS) - 1);

	/*
	* allocbitmap is the inverted holemask so every set bit represents
	* allocated inodes. To expand from 16-bit holemask granularity to
	* 64-bit (e.g., bit-per-inode), set inodespbit bits in the target
	* bitmap for every holemask bit.
	*/
	nextbit = xfs_next_bit(&allocbitmap, 1, 0);
	while (nextbit != -1) {
	ASSERT(nextbit < (sizeof(rec->ir_holemask) * NBBY));

	bitmap \|= (inodespbit <<
	(nextbit * XFS_INODES_PER_HOLEMASK_BIT));

	nextbit = xfs_next_bit(&allocbitmap, 1, nextbit + 1);
	}

	return bitmap;
	}

	#if defined(DEBUG) \|\| defined(XFS_WARN)
	/*
	* Verify that an in-core inode record has a valid inode count.
	*/
	int
	xfs_inobt_rec_check_count(
	struct xfs_mount *mp,
	struct xfs_inobt_rec_incore *rec)
	{
	int inocount = 0;
	int nextbit = 0;
	uint64_t allocbmap;
	int wordsz;

	wordsz = sizeof(allocbmap) / sizeof(unsigned int);
	allocbmap = xfs_inobt_irec_to_allocmask(rec);

	nextbit = xfs_next_bit((uint *) &allocbmap, wordsz, nextbit);
	while (nextbit != -1) {
	inocount++;
	nextbit = xfs_next_bit((uint *) &allocbmap, wordsz,
	nextbit + 1);
	}

	if (inocount != rec->ir_count)
	return -EFSCORRUPTED;

	return 0;
	}
	#endif /* DEBUG */