cregit-Linux how code gets into the kernel

Release 4.10 fs/ocfs2/suballoc.c

Directory: fs/ocfs2
/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * suballoc.c
 *
 * metadata alloc and free
 * Inspired by ext3 block groups.
 *
 * Copyright (C) 2002, 2004 Oracle.  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; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will 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 to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/fs.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>

#include <cluster/masklog.h>

#include "ocfs2.h"

#include "alloc.h"
#include "blockcheck.h"
#include "dlmglue.h"
#include "inode.h"
#include "journal.h"
#include "localalloc.h"
#include "suballoc.h"
#include "super.h"
#include "sysfile.h"
#include "uptodate.h"
#include "ocfs2_trace.h"

#include "buffer_head_io.h"


#define NOT_ALLOC_NEW_GROUP		0

#define ALLOC_NEW_GROUP			0x1

#define ALLOC_GROUPS_FROM_GLOBAL	0x2


#define OCFS2_MAX_TO_STEAL		1024


struct ocfs2_suballoc_result {
	
u64		sr_bg_blkno;	/* The bg we allocated from.  Set
                                           to 0 when a block group is
                                           contiguous. */
	
u64		sr_bg_stable_blkno; /*
                                             * Doesn't change, always
                                             * set to target block
                                             * group descriptor
                                             * block.
                                             */
	
u64		sr_blkno;	/* The first allocated block */
	
unsigned int	sr_bit_offset;	/* The bit in the bg */
	
unsigned int	sr_bits;	/* How many bits we claimed */
};




static u64 ocfs2_group_from_res(struct ocfs2_suballoc_result *res)
{
	if (res->sr_blkno == 0)
		return 0;

	if (res->sr_bg_blkno)
		return res->sr_bg_blkno;

	return ocfs2_which_suballoc_group(res->sr_blkno, res->sr_bit_offset);
}


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static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
static int ocfs2_block_group_fill(handle_t *handle,
				  struct inode *alloc_inode,
				  struct buffer_head *bg_bh,
				  u64 group_blkno,
				  unsigned int group_clusters,
				  u16 my_chain,
				  struct ocfs2_chain_list *cl);
static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
				   struct inode *alloc_inode,
				   struct buffer_head *bh,
				   u64 max_block,
				   u64 *last_alloc_group,
				   int flags);

static int ocfs2_cluster_group_search(struct inode *inode,
				      struct buffer_head *group_bh,
				      u32 bits_wanted, u32 min_bits,
				      u64 max_block,
				      struct ocfs2_suballoc_result *res);
static int ocfs2_block_group_search(struct inode *inode,
				    struct buffer_head *group_bh,
				    u32 bits_wanted, u32 min_bits,
				    u64 max_block,
				    struct ocfs2_suballoc_result *res);
static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
				     handle_t *handle,
				     u32 bits_wanted,
				     u32 min_bits,
				     struct ocfs2_suballoc_result *res);
static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
					 int nr);
static int ocfs2_relink_block_group(handle_t *handle,
				    struct inode *alloc_inode,
				    struct buffer_head *fe_bh,
				    struct buffer_head *bg_bh,
				    struct buffer_head *prev_bg_bh,
				    u16 chain);
static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
						     u32 wanted);
static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
						   u64 bg_blkno,
						   u16 bg_bit_off);
static inline void ocfs2_block_to_cluster_group(struct inode *inode,
						u64 data_blkno,
						u64 *bg_blkno,
						u16 *bg_bit_off);
static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
					     u32 bits_wanted, u64 max_block,
					     int flags,
					     struct ocfs2_alloc_context **ac);




void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
{
	struct inode *inode = ac->ac_inode;

	if (inode) {
		if (ac->ac_which != OCFS2_AC_USE_LOCAL)
			ocfs2_inode_unlock(inode, 1);

		inode_unlock(inode);

		iput(inode);
		ac->ac_inode = NULL;
	}
	brelse(ac->ac_bh);
	ac->ac_bh = NULL;
	ac->ac_resv = NULL;
	kfree(ac->ac_find_loc_priv);
	ac->ac_find_loc_priv = NULL;
}


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void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
{
	ocfs2_free_ac_resource(ac);
	kfree(ac);
}


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static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
{
	return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
}


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#define do_error(fmt, ...)						\
do {                                                                    \
        if (resize)                                                     \
                mlog(ML_ERROR, fmt, ##__VA_ARGS__);                     \
        else                                                            \
                return ocfs2_error(sb, fmt, ##__VA_ARGS__);             \
} while (0)




static int ocfs2_validate_gd_self(struct super_block *sb,
				  struct buffer_head *bh,
				  int resize)
{
	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;

	if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
		do_error("Group descriptor #%llu has bad signature %.*s\n",
			 (unsigned long long)bh->b_blocknr, 7,
			 gd->bg_signature);
	}

	if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
		do_error("Group descriptor #%llu has an invalid bg_blkno of %llu\n",
			 (unsigned long long)bh->b_blocknr,
			 (unsigned long long)le64_to_cpu(gd->bg_blkno));
	}

	if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
		do_error("Group descriptor #%llu has an invalid fs_generation of #%u\n",
			 (unsigned long long)bh->b_blocknr,
			 le32_to_cpu(gd->bg_generation));
	}

	if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
		do_error("Group descriptor #%llu has bit count %u but claims that %u are free\n",
			 (unsigned long long)bh->b_blocknr,
			 le16_to_cpu(gd->bg_bits),
			 le16_to_cpu(gd->bg_free_bits_count));
	}

	if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
		do_error("Group descriptor #%llu has bit count %u but max bitmap bits of %u\n",
			 (unsigned long long)bh->b_blocknr,
			 le16_to_cpu(gd->bg_bits),
			 8 * le16_to_cpu(gd->bg_size));
	}

	return 0;
}


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static int ocfs2_validate_gd_parent(struct super_block *sb,
				    struct ocfs2_dinode *di,
				    struct buffer_head *bh,
				    int resize)
{
	unsigned int max_bits;
	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;

	if (di->i_blkno != gd->bg_parent_dinode) {
		do_error("Group descriptor #%llu has bad parent pointer (%llu, expected %llu)\n",
			 (unsigned long long)bh->b_blocknr,
			 (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
			 (unsigned long long)le64_to_cpu(di->i_blkno));
	}

	max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
	if (le16_to_cpu(gd->bg_bits) > max_bits) {
		do_error("Group descriptor #%llu has bit count of %u\n",
			 (unsigned long long)bh->b_blocknr,
			 le16_to_cpu(gd->bg_bits));
	}

	/* In resize, we may meet the case bg_chain == cl_next_free_rec. */
	if ((le16_to_cpu(gd->bg_chain) >
	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
	    ((le16_to_cpu(gd->bg_chain) ==
	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
		do_error("Group descriptor #%llu has bad chain %u\n",
			 (unsigned long long)bh->b_blocknr,
			 le16_to_cpu(gd->bg_chain));
	}

	return 0;
}


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#undef do_error

/*
 * This version only prints errors.  It does not fail the filesystem, and
 * exists only for resize.
 */



int ocfs2_check_group_descriptor(struct super_block *sb,
				 struct ocfs2_dinode *di,
				 struct buffer_head *bh)
{
	int rc;
	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;

	BUG_ON(!buffer_uptodate(bh));

	/*
         * If the ecc fails, we return the error but otherwise
         * leave the filesystem running.  We know any error is
         * local to this block.
         */
	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
	if (rc) {
		mlog(ML_ERROR,
		     "Checksum failed for group descriptor %llu\n",
		     (unsigned long long)bh->b_blocknr);
	} else
		rc = ocfs2_validate_gd_self(sb, bh, 1);
	if (!rc)
		rc = ocfs2_validate_gd_parent(sb, di, bh, 1);

	return rc;
}


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static int ocfs2_validate_group_descriptor(struct super_block *sb,
					   struct buffer_head *bh)
{
	int rc;
	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;

	trace_ocfs2_validate_group_descriptor(
					(unsigned long long)bh->b_blocknr);

	BUG_ON(!buffer_uptodate(bh));

	/*
         * If the ecc fails, we return the error but otherwise
         * leave the filesystem running.  We know any error is
         * local to this block.
         */
	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
	if (rc)
		return rc;

	/*
         * Errors after here are fatal.
         */

	return ocfs2_validate_gd_self(sb, bh, 0);
}


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int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
				u64 gd_blkno, struct buffer_head **bh)
{
	int rc;
	struct buffer_head *tmp = *bh;

	rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
			      ocfs2_validate_group_descriptor);
	if (rc)
		goto out;

	rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
	if (rc) {
		brelse(tmp);
		goto out;
	}

	/* If ocfs2_read_block() got us a new bh, pass it up. */
	if (!*bh)
		*bh = tmp;

out:
	return rc;
}


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static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
					  struct ocfs2_group_desc *bg,
					  struct ocfs2_chain_list *cl,
					  u64 p_blkno, unsigned int clusters)
{
	struct ocfs2_extent_list *el = &bg->bg_list;
	struct ocfs2_extent_rec *rec;

	BUG_ON(!ocfs2_supports_discontig_bg(osb));
	if (!el->l_next_free_rec)
		el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
	rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
	rec->e_blkno = cpu_to_le64(p_blkno);
	rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
				  le16_to_cpu(cl->cl_bpc));
	rec->e_leaf_clusters = cpu_to_le16(clusters);
	le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
	le16_add_cpu(&bg->bg_free_bits_count,
		     clusters * le16_to_cpu(cl->cl_bpc));
	le16_add_cpu(&el->l_next_free_rec, 1);
}


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static int ocfs2_block_group_fill(handle_t *handle,
				  struct inode *alloc_inode,
				  struct buffer_head *bg_bh,
				  u64 group_blkno,
				  unsigned int group_clusters,
				  u16 my_chain,
				  struct ocfs2_chain_list *cl)
{
	int status = 0;
	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
	struct super_block * sb = alloc_inode->i_sb;

	if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
		status = ocfs2_error(alloc_inode->i_sb,
				     "group block (%llu) != b_blocknr (%llu)\n",
				     (unsigned long long)group_blkno,
				     (unsigned long long) bg_bh->b_blocknr);
		goto bail;
	}

	status = ocfs2_journal_access_gd(handle,
					 INODE_CACHE(alloc_inode),
					 bg_bh,
					 OCFS2_JOURNAL_ACCESS_CREATE);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	memset(bg, 0, sb->s_blocksize);
	strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
	bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
	bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1,
						osb->s_feature_incompat));
	bg->bg_chain = cpu_to_le16(my_chain);
	bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
	bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
	bg->bg_blkno = cpu_to_le64(group_blkno);
	if (group_clusters == le16_to_cpu(cl->cl_cpg))
		bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
	else
		ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
					      group_clusters);

	/* set the 1st bit in the bitmap to account for the descriptor block */
	ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
	bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);

	ocfs2_journal_dirty(handle, bg_bh);

	/* There is no need to zero out or otherwise initialize the
         * other blocks in a group - All valid FS metadata in a block
         * group stores the superblock fs_generation value at
         * allocation time. */

bail:
	if (status)
		mlog_errno(status);
	return status;
}


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static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
{
	u16 curr, best;

	best = curr = 0;
	while (curr < le16_to_cpu(cl->cl_count)) {
		if (le32_to_cpu(cl->cl_recs[best].c_total) >
		    le32_to_cpu(cl->cl_recs[curr].c_total))
			best = curr;
		curr++;
	}
	return best;
}


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static struct buffer_head *

ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
			       struct inode *alloc_inode,
			       struct ocfs2_alloc_context *ac,
			       struct ocfs2_chain_list *cl)
{
	int status;
	u32 bit_off, num_bits;
	u64 bg_blkno;
	struct buffer_head *bg_bh;
	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);

	status = ocfs2_claim_clusters(handle, ac,
				      le16_to_cpu(cl->cl_cpg), &bit_off,
				      &num_bits);
	if (status < 0) {
		if (status != -ENOSPC)
			mlog_errno(status);
		goto bail;
	}

	/* setup the group */
	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
	trace_ocfs2_block_group_alloc_contig(
	     (unsigned long long)bg_blkno, alloc_rec);

	bg_bh = sb_getblk(osb->sb, bg_blkno);
	if (!bg_bh) {
		status = -ENOMEM;
		mlog_errno(status);
		goto bail;
	}
	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);

	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
					bg_blkno, num_bits, alloc_rec, cl);
	if (status < 0) {
		brelse(bg_bh);
		mlog_errno(status);
	}

bail:
	return status ? ERR_PTR(status) : bg_bh;
}


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static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
					handle_t *handle,
					struct ocfs2_alloc_context *ac,
					unsigned int min_bits,
					u32 *bit_off, u32 *num_bits)
{
	int status = 0;

	while (min_bits) {
		status = ocfs2_claim_clusters(handle, ac, min_bits,
					      bit_off, num_bits);
		if (status != -ENOSPC)
			break;

		min_bits >>= 1;
	}

	return status;
}


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static int ocfs2_block_group_grow_discontig(handle_t *handle,
					    struct inode *alloc_inode,
					    struct buffer_head *bg_bh,
					    struct ocfs2_alloc_context *ac,
					    struct ocfs2_chain_list *cl,
					    unsigned int min_bits)
{
	int status;
	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
	struct ocfs2_group_desc *bg =
		(struct ocfs2_group_desc *)bg_bh->b_data;
	unsigned int needed = le16_to_cpu(cl->cl_cpg) -
			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
	u32 p_cpos, clusters;
	u64 p_blkno;
	struct ocfs2_extent_list *el = &bg->bg_list;

	status = ocfs2_journal_access_gd(handle,
					 INODE_CACHE(alloc_inode),
					 bg_bh,
					 OCFS2_JOURNAL_ACCESS_CREATE);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	while ((needed > 0) && (le16_to_cpu(el->l_next_free_rec) <
				le16_to_cpu(el->l_count))) {
		if (min_bits > needed)
			min_bits = needed;
		status = ocfs2_block_group_claim_bits(osb, handle, ac,
						      min_bits, &p_cpos,
						      &clusters);
		if (status < 0) {
			if (status != -ENOSPC)
				mlog_errno(status);
			goto bail;
		}
		p_blkno = ocfs2_clusters_to_blocks(osb->sb, p_cpos);
		ocfs2_bg_discontig_add_extent(osb, bg, cl, p_blkno,
					      clusters);

		min_bits = clusters;
		needed = le16_to_cpu(cl->cl_cpg) -
			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
	}

	if (needed > 0) {
		/*
                 * We have used up all the extent rec but can't fill up
                 * the cpg. So bail out.
                 */
		status = -ENOSPC;
		goto bail;
	}

	ocfs2_journal_dirty(handle, bg_bh);

bail:
	return status;
}


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static void ocfs2_bg_alloc_cleanup(handle_t *handle,
				   struct ocfs2_alloc_context *cluster_ac,
				   struct inode *alloc_inode,
				   struct buffer_head *bg_bh)
{
	int i, ret;
	struct ocfs2_group_desc *bg;
	struct ocfs2_extent_list *el;
	struct ocfs2_extent_rec *rec;

	if (!bg_bh)
		return;

	bg = (struct ocfs2_group_desc *)bg_bh->b_data;
	el = &bg->bg_list;
	for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
		rec = &el->l_recs[i];
		ret = ocfs2_free_clusters(handle, cluster_ac->ac_inode,
					  cluster_ac->ac_bh,
					  le64_to_cpu(rec->e_blkno),
					  le16_to_cpu(rec->e_leaf_clusters));
		if (ret)
			mlog_errno(ret);
		/* Try all the clusters to free */
	}

	ocfs2_remove_from_cache(INODE_CACHE(alloc_inode), bg_bh);
	brelse(bg_bh);
}


Contributors
PersonTokensPropCommitsCommitProp
joel beckerjoel becker15299.35%266.67%


al viroal viro10.65%133.33%


Total153100.00%3100.00%





static struct buffer_head *

ocfs2_block_group_alloc_discontig(handle_t *handle,
				  struct inode *alloc_inode,
				  struct ocfs2_alloc_context *ac,
				  struct ocfs2_chain_list *cl)
{
	int status;
	u32 bit_off, num_bits;
	u64 bg_blkno;
	unsigned int min_bits = le16_to_cpu(cl->cl_cpg) >> 1;
	struct buffer_head *bg_bh = NULL;
	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);

	if (!ocfs2_supports_discontig_bg(osb)) {
		status = -ENOSPC;
		goto bail;
	}

	status = ocfs2_extend_trans(handle,
				    ocfs2_calc_bg_discontig_credits(osb->sb));
	if (status) {
		mlog_errno(status);
		goto bail;
	}

	/*
         * We're going to be grabbing from multiple cluster groups.
         * We don't have enough credits to relink them all, and the
         * cluster groups will be staying in cache for the duration of
         * this operation.
         */
	ac->ac_disable_chain_relink = 1;

	/* Claim the first region */
	status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
					      &bit_off, &num_bits);
	if (status < 0) {
		if (status != -ENOSPC)
			mlog_errno(status);
		goto bail;
	}
	min_bits = num_bits;

	/* setup the group */
	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
	trace_ocfs2_block_group_alloc_discontig(
				(unsigned long long)bg_blkno, alloc_rec);

	bg_bh = sb_getblk(osb->sb, bg_blkno);
	if (!bg_bh) {
		status =