localalloc.c 29.8 KB
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/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * localalloc.c
 *
 * Node local data allocation
 *
 * 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 <linux/bitops.h>

#define MLOG_MASK_PREFIX ML_DISK_ALLOC
#include <cluster/masklog.h>

#include "ocfs2.h"

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

#include "buffer_head_io.h"

#define OCFS2_LOCAL_ALLOC(dinode)	(&((dinode)->id2.i_lab))

static u32 ocfs2_local_alloc_count_bits(struct ocfs2_dinode *alloc);

static int ocfs2_local_alloc_find_clear_bits(struct ocfs2_super *osb,
					     struct ocfs2_dinode *alloc,
					     u32 numbits);

static void ocfs2_clear_local_alloc(struct ocfs2_dinode *alloc);

static int ocfs2_sync_local_to_main(struct ocfs2_super *osb,
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				    handle_t *handle,
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				    struct ocfs2_dinode *alloc,
				    struct inode *main_bm_inode,
				    struct buffer_head *main_bm_bh);

static int ocfs2_local_alloc_reserve_for_window(struct ocfs2_super *osb,
						struct ocfs2_alloc_context **ac,
						struct inode **bitmap_inode,
						struct buffer_head **bitmap_bh);

static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb,
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					handle_t *handle,
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					struct ocfs2_alloc_context *ac);

static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb,
					  struct inode *local_alloc_inode);

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static inline int ocfs2_la_state_enabled(struct ocfs2_super *osb)
{
	return (osb->local_alloc_state == OCFS2_LA_THROTTLED ||
		osb->local_alloc_state == OCFS2_LA_ENABLED);
}

void ocfs2_local_alloc_seen_free_bits(struct ocfs2_super *osb,
				      unsigned int num_clusters)
{
	spin_lock(&osb->osb_lock);
	if (osb->local_alloc_state == OCFS2_LA_DISABLED ||
	    osb->local_alloc_state == OCFS2_LA_THROTTLED)
		if (num_clusters >= osb->local_alloc_default_bits) {
			cancel_delayed_work(&osb->la_enable_wq);
			osb->local_alloc_state = OCFS2_LA_ENABLED;
		}
	spin_unlock(&osb->osb_lock);
}

void ocfs2_la_enable_worker(struct work_struct *work)
{
	struct ocfs2_super *osb =
		container_of(work, struct ocfs2_super,
			     la_enable_wq.work);
	spin_lock(&osb->osb_lock);
	osb->local_alloc_state = OCFS2_LA_ENABLED;
	spin_unlock(&osb->osb_lock);
}

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/*
 * Tell us whether a given allocation should use the local alloc
 * file. Otherwise, it has to go to the main bitmap.
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 *
 * This function does semi-dirty reads of local alloc size and state!
 * This is ok however, as the values are re-checked once under mutex.
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 */
int ocfs2_alloc_should_use_local(struct ocfs2_super *osb, u64 bits)
{
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	int ret = 0;
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	int la_bits;

	spin_lock(&osb->osb_lock);
	la_bits = osb->local_alloc_bits;
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	if (!ocfs2_la_state_enabled(osb))
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		goto bail;
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	/* la_bits should be at least twice the size (in clusters) of
	 * a new block group. We want to be sure block group
	 * allocations go through the local alloc, so allow an
	 * allocation to take up to half the bitmap. */
	if (bits > (la_bits / 2))
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		goto bail;
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	ret = 1;
bail:
	mlog(0, "state=%d, bits=%llu, la_bits=%d, ret=%d\n",
	     osb->local_alloc_state, (unsigned long long)bits, la_bits, ret);
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	spin_unlock(&osb->osb_lock);
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	return ret;
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}

int ocfs2_load_local_alloc(struct ocfs2_super *osb)
{
	int status = 0;
	struct ocfs2_dinode *alloc = NULL;
	struct buffer_head *alloc_bh = NULL;
	u32 num_used;
	struct inode *inode = NULL;
	struct ocfs2_local_alloc *la;

	mlog_entry_void();

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	if (osb->local_alloc_bits == 0)
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		goto bail;

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	if (osb->local_alloc_bits >= osb->bitmap_cpg) {
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		mlog(ML_NOTICE, "Requested local alloc window %d is larger "
		     "than max possible %u. Using defaults.\n",
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		     osb->local_alloc_bits, (osb->bitmap_cpg - 1));
		osb->local_alloc_bits =
			ocfs2_megabytes_to_clusters(osb->sb,
						    OCFS2_DEFAULT_LOCAL_ALLOC_SIZE);
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	}

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	/* read the alloc off disk */
	inode = ocfs2_get_system_file_inode(osb, LOCAL_ALLOC_SYSTEM_INODE,
					    osb->slot_num);
	if (!inode) {
		status = -EINVAL;
		mlog_errno(status);
		goto bail;
	}

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	status = ocfs2_read_inode_block_full(inode, &alloc_bh,
					     OCFS2_BH_IGNORE_CACHE);
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	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	alloc = (struct ocfs2_dinode *) alloc_bh->b_data;
	la = OCFS2_LOCAL_ALLOC(alloc);

	if (!(le32_to_cpu(alloc->i_flags) &
	    (OCFS2_LOCAL_ALLOC_FL|OCFS2_BITMAP_FL))) {
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		mlog(ML_ERROR, "Invalid local alloc inode, %llu\n",
		     (unsigned long long)OCFS2_I(inode)->ip_blkno);
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		status = -EINVAL;
		goto bail;
	}

	if ((la->la_size == 0) ||
	    (le16_to_cpu(la->la_size) > ocfs2_local_alloc_size(inode->i_sb))) {
		mlog(ML_ERROR, "Local alloc size is invalid (la_size = %u)\n",
		     le16_to_cpu(la->la_size));
		status = -EINVAL;
		goto bail;
	}

	/* do a little verification. */
	num_used = ocfs2_local_alloc_count_bits(alloc);

	/* hopefully the local alloc has always been recovered before
	 * we load it. */
	if (num_used
	    || alloc->id1.bitmap1.i_used
	    || alloc->id1.bitmap1.i_total
	    || la->la_bm_off)
		mlog(ML_ERROR, "Local alloc hasn't been recovered!\n"
		     "found = %u, set = %u, taken = %u, off = %u\n",
		     num_used, le32_to_cpu(alloc->id1.bitmap1.i_used),
		     le32_to_cpu(alloc->id1.bitmap1.i_total),
		     OCFS2_LOCAL_ALLOC(alloc)->la_bm_off);

	osb->local_alloc_bh = alloc_bh;
	osb->local_alloc_state = OCFS2_LA_ENABLED;

bail:
	if (status < 0)
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		brelse(alloc_bh);
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	if (inode)
		iput(inode);

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	mlog(0, "Local alloc window bits = %d\n", osb->local_alloc_bits);
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	mlog_exit(status);
	return status;
}

/*
 * return any unused bits to the bitmap and write out a clean
 * local_alloc.
 *
 * local_alloc_bh is optional. If not passed, we will simply use the
 * one off osb. If you do pass it however, be warned that it *will* be
 * returned brelse'd and NULL'd out.*/
void ocfs2_shutdown_local_alloc(struct ocfs2_super *osb)
{
	int status;
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	handle_t *handle;
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	struct inode *local_alloc_inode = NULL;
	struct buffer_head *bh = NULL;
	struct buffer_head *main_bm_bh = NULL;
	struct inode *main_bm_inode = NULL;
	struct ocfs2_dinode *alloc_copy = NULL;
	struct ocfs2_dinode *alloc = NULL;

	mlog_entry_void();

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	cancel_delayed_work(&osb->la_enable_wq);
	flush_workqueue(ocfs2_wq);

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	if (osb->local_alloc_state == OCFS2_LA_UNUSED)
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		goto out;
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	local_alloc_inode =
		ocfs2_get_system_file_inode(osb,
					    LOCAL_ALLOC_SYSTEM_INODE,
					    osb->slot_num);
	if (!local_alloc_inode) {
		status = -ENOENT;
		mlog_errno(status);
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		goto out;
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	}

	osb->local_alloc_state = OCFS2_LA_DISABLED;

	main_bm_inode = ocfs2_get_system_file_inode(osb,
						    GLOBAL_BITMAP_SYSTEM_INODE,
						    OCFS2_INVALID_SLOT);
	if (!main_bm_inode) {
		status = -EINVAL;
		mlog_errno(status);
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		goto out;
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	}

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	mutex_lock(&main_bm_inode->i_mutex);

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	status = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 1);
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	if (status < 0) {
		mlog_errno(status);
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		goto out_mutex;
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	}

	/* WINDOW_MOVE_CREDITS is a bit heavy... */
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	handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
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	if (IS_ERR(handle)) {
		mlog_errno(PTR_ERR(handle));
		handle = NULL;
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		goto out_unlock;
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	}

	bh = osb->local_alloc_bh;
	alloc = (struct ocfs2_dinode *) bh->b_data;

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	alloc_copy = kmalloc(bh->b_size, GFP_NOFS);
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	if (!alloc_copy) {
		status = -ENOMEM;
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		goto out_commit;
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	}
	memcpy(alloc_copy, alloc, bh->b_size);

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	status = ocfs2_journal_access_di(handle, local_alloc_inode, bh,
					 OCFS2_JOURNAL_ACCESS_WRITE);
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	if (status < 0) {
		mlog_errno(status);
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		goto out_commit;
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	}

	ocfs2_clear_local_alloc(alloc);

	status = ocfs2_journal_dirty(handle, bh);
	if (status < 0) {
		mlog_errno(status);
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		goto out_commit;
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	}

	brelse(bh);
	osb->local_alloc_bh = NULL;
	osb->local_alloc_state = OCFS2_LA_UNUSED;

	status = ocfs2_sync_local_to_main(osb, handle, alloc_copy,
					  main_bm_inode, main_bm_bh);
	if (status < 0)
		mlog_errno(status);

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out_commit:
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	ocfs2_commit_trans(osb, handle);
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out_unlock:
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	brelse(main_bm_bh);
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	ocfs2_inode_unlock(main_bm_inode, 1);
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out_mutex:
	mutex_unlock(&main_bm_inode->i_mutex);
	iput(main_bm_inode);

out:
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	if (local_alloc_inode)
		iput(local_alloc_inode);

	if (alloc_copy)
		kfree(alloc_copy);

	mlog_exit_void();
}

/*
 * We want to free the bitmap bits outside of any recovery context as
 * we'll need a cluster lock to do so, but we must clear the local
 * alloc before giving up the recovered nodes journal. To solve this,
 * we kmalloc a copy of the local alloc before it's change for the
 * caller to process with ocfs2_complete_local_alloc_recovery
 */
int ocfs2_begin_local_alloc_recovery(struct ocfs2_super *osb,
				     int slot_num,
				     struct ocfs2_dinode **alloc_copy)
{
	int status = 0;
	struct buffer_head *alloc_bh = NULL;
	struct inode *inode = NULL;
	struct ocfs2_dinode *alloc;

	mlog_entry("(slot_num = %d)\n", slot_num);

	*alloc_copy = NULL;

	inode = ocfs2_get_system_file_inode(osb,
					    LOCAL_ALLOC_SYSTEM_INODE,
					    slot_num);
	if (!inode) {
		status = -EINVAL;
		mlog_errno(status);
		goto bail;
	}

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	mutex_lock(&inode->i_mutex);
376

377 378
	status = ocfs2_read_inode_block_full(inode, &alloc_bh,
					     OCFS2_BH_IGNORE_CACHE);
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	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	*alloc_copy = kmalloc(alloc_bh->b_size, GFP_KERNEL);
	if (!(*alloc_copy)) {
		status = -ENOMEM;
		goto bail;
	}
	memcpy((*alloc_copy), alloc_bh->b_data, alloc_bh->b_size);

	alloc = (struct ocfs2_dinode *) alloc_bh->b_data;
	ocfs2_clear_local_alloc(alloc);

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	ocfs2_compute_meta_ecc(osb->sb, alloc_bh->b_data, &alloc->i_check);
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	status = ocfs2_write_block(osb, alloc_bh, INODE_CACHE(inode));
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	if (status < 0)
		mlog_errno(status);

bail:
	if ((status < 0) && (*alloc_copy)) {
		kfree(*alloc_copy);
		*alloc_copy = NULL;
	}

405
	brelse(alloc_bh);
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	if (inode) {
408
		mutex_unlock(&inode->i_mutex);
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		iput(inode);
	}

	mlog_exit(status);
	return status;
}

/*
 * Step 2: By now, we've completed the journal recovery, we've stamped
 * a clean local alloc on disk and dropped the node out of the
 * recovery map. Dlm locks will no longer stall, so lets clear out the
 * main bitmap.
 */
int ocfs2_complete_local_alloc_recovery(struct ocfs2_super *osb,
					struct ocfs2_dinode *alloc)
{
	int status;
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	handle_t *handle;
427
	struct buffer_head *main_bm_bh = NULL;
428
	struct inode *main_bm_inode;
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	mlog_entry_void();

	main_bm_inode = ocfs2_get_system_file_inode(osb,
						    GLOBAL_BITMAP_SYSTEM_INODE,
						    OCFS2_INVALID_SLOT);
	if (!main_bm_inode) {
		status = -EINVAL;
		mlog_errno(status);
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		goto out;
439 440
	}

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	mutex_lock(&main_bm_inode->i_mutex);

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	status = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 1);
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	if (status < 0) {
		mlog_errno(status);
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		goto out_mutex;
447 448
	}

449
	handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
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	if (IS_ERR(handle)) {
		status = PTR_ERR(handle);
		handle = NULL;
		mlog_errno(status);
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		goto out_unlock;
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	}

	/* we want the bitmap change to be recorded on disk asap */
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	handle->h_sync = 1;
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	status = ocfs2_sync_local_to_main(osb, handle, alloc,
					  main_bm_inode, main_bm_bh);
	if (status < 0)
		mlog_errno(status);

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	ocfs2_commit_trans(osb, handle);
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out_unlock:
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	ocfs2_inode_unlock(main_bm_inode, 1);
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out_mutex:
	mutex_unlock(&main_bm_inode->i_mutex);
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473
	brelse(main_bm_bh);
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475
	iput(main_bm_inode);
476

477
out:
478 479
	if (!status)
		ocfs2_init_inode_steal_slot(osb);
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	mlog_exit(status);
	return status;
}

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/* Check to see if the local alloc window is within ac->ac_max_block */
static int ocfs2_local_alloc_in_range(struct inode *inode,
				      struct ocfs2_alloc_context *ac,
				      u32 bits_wanted)
{
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct ocfs2_dinode *alloc;
	struct ocfs2_local_alloc *la;
	int start;
	u64 block_off;

	if (!ac->ac_max_block)
		return 1;

	alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
	la = OCFS2_LOCAL_ALLOC(alloc);

	start = ocfs2_local_alloc_find_clear_bits(osb, alloc, bits_wanted);
	if (start == -1) {
		mlog_errno(-ENOSPC);
		return 0;
	}

	/*
	 * Converting (bm_off + start + bits_wanted) to blocks gives us
	 * the blkno just past our actual allocation.  This is perfect
	 * to compare with ac_max_block.
	 */
	block_off = ocfs2_clusters_to_blocks(inode->i_sb,
					     le32_to_cpu(la->la_bm_off) +
					     start + bits_wanted);
	mlog(0, "Checking %llu against %llu\n",
	     (unsigned long long)block_off,
	     (unsigned long long)ac->ac_max_block);
	if (block_off > ac->ac_max_block)
		return 0;

	return 1;
}

524
/*
525
 * make sure we've got at least bits_wanted contiguous bits in the
526
 * local alloc. You lose them when you drop i_mutex.
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 *
 * We will add ourselves to the transaction passed in, but may start
 * our own in order to shift windows.
 */
int ocfs2_reserve_local_alloc_bits(struct ocfs2_super *osb,
				   u32 bits_wanted,
				   struct ocfs2_alloc_context *ac)
{
	int status;
	struct ocfs2_dinode *alloc;
	struct inode *local_alloc_inode;
	unsigned int free_bits;

	mlog_entry_void();

	BUG_ON(!ac);

	local_alloc_inode =
		ocfs2_get_system_file_inode(osb,
					    LOCAL_ALLOC_SYSTEM_INODE,
					    osb->slot_num);
	if (!local_alloc_inode) {
		status = -ENOENT;
		mlog_errno(status);
		goto bail;
	}
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	mutex_lock(&local_alloc_inode->i_mutex);

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	/*
	 * We must double check state and allocator bits because
	 * another process may have changed them while holding i_mutex.
	 */
	spin_lock(&osb->osb_lock);
	if (!ocfs2_la_state_enabled(osb) ||
	    (bits_wanted > osb->local_alloc_bits)) {
		spin_unlock(&osb->osb_lock);
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		status = -ENOSPC;
		goto bail;
	}
567
	spin_unlock(&osb->osb_lock);
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	alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;

571
#ifdef CONFIG_OCFS2_DEBUG_FS
572 573
	if (le32_to_cpu(alloc->id1.bitmap1.i_used) !=
	    ocfs2_local_alloc_count_bits(alloc)) {
574
		ocfs2_error(osb->sb, "local alloc inode %llu says it has "
575
			    "%u free bits, but a count shows %u",
576
			    (unsigned long long)le64_to_cpu(alloc->i_blkno),
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			    le32_to_cpu(alloc->id1.bitmap1.i_used),
			    ocfs2_local_alloc_count_bits(alloc));
		status = -EIO;
		goto bail;
	}
582
#endif
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	free_bits = le32_to_cpu(alloc->id1.bitmap1.i_total) -
		le32_to_cpu(alloc->id1.bitmap1.i_used);
	if (bits_wanted > free_bits) {
		/* uhoh, window change time. */
		status =
			ocfs2_local_alloc_slide_window(osb, local_alloc_inode);
		if (status < 0) {
			if (status != -ENOSPC)
				mlog_errno(status);
			goto bail;
		}
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		/*
		 * Under certain conditions, the window slide code
		 * might have reduced the number of bits available or
		 * disabled the the local alloc entirely. Re-check
		 * here and return -ENOSPC if necessary.
		 */
		status = -ENOSPC;
		if (!ocfs2_la_state_enabled(osb))
			goto bail;

		free_bits = le32_to_cpu(alloc->id1.bitmap1.i_total) -
			le32_to_cpu(alloc->id1.bitmap1.i_used);
		if (bits_wanted > free_bits)
			goto bail;
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	}

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	if (ac->ac_max_block)
		mlog(0, "Calling in_range for max block %llu\n",
		     (unsigned long long)ac->ac_max_block);

	if (!ocfs2_local_alloc_in_range(local_alloc_inode, ac,
					bits_wanted)) {
		/*
		 * The window is outside ac->ac_max_block.
		 * This errno tells the caller to keep localalloc enabled
		 * but to get the allocation from the main bitmap.
		 */
		status = -EFBIG;
		goto bail;
	}

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	ac->ac_inode = local_alloc_inode;
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	/* We should never use localalloc from another slot */
	ac->ac_alloc_slot = osb->slot_num;
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	ac->ac_which = OCFS2_AC_USE_LOCAL;
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	get_bh(osb->local_alloc_bh);
	ac->ac_bh = osb->local_alloc_bh;
	status = 0;
bail:
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	if (status < 0 && local_alloc_inode) {
		mutex_unlock(&local_alloc_inode->i_mutex);
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		iput(local_alloc_inode);
638
	}
639

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	mlog(0, "bits=%d, slot=%d, ret=%d\n", bits_wanted, osb->slot_num,
	     status);

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	mlog_exit(status);
	return status;
}

int ocfs2_claim_local_alloc_bits(struct ocfs2_super *osb,
648
				 handle_t *handle,
649
				 struct ocfs2_alloc_context *ac,
650
				 u32 bits_wanted,
651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680
				 u32 *bit_off,
				 u32 *num_bits)
{
	int status, start;
	struct inode *local_alloc_inode;
	void *bitmap;
	struct ocfs2_dinode *alloc;
	struct ocfs2_local_alloc *la;

	mlog_entry_void();
	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL);

	local_alloc_inode = ac->ac_inode;
	alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
	la = OCFS2_LOCAL_ALLOC(alloc);

	start = ocfs2_local_alloc_find_clear_bits(osb, alloc, bits_wanted);
	if (start == -1) {
		/* TODO: Shouldn't we just BUG here? */
		status = -ENOSPC;
		mlog_errno(status);
		goto bail;
	}

	bitmap = la->la_bitmap;
	*bit_off = le32_to_cpu(la->la_bm_off) + start;
	/* local alloc is always contiguous by nature -- we never
	 * delete bits from it! */
	*num_bits = bits_wanted;

681 682 683
	status = ocfs2_journal_access_di(handle, local_alloc_inode,
					 osb->local_alloc_bh,
					 OCFS2_JOURNAL_ACCESS_WRITE);
684 685 686 687 688 689 690 691
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	while(bits_wanted--)
		ocfs2_set_bit(start++, bitmap);

692
	le32_add_cpu(&alloc->id1.bitmap1.i_used, *num_bits);
693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822

	status = ocfs2_journal_dirty(handle, osb->local_alloc_bh);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	status = 0;
bail:
	mlog_exit(status);
	return status;
}

static u32 ocfs2_local_alloc_count_bits(struct ocfs2_dinode *alloc)
{
	int i;
	u8 *buffer;
	u32 count = 0;
	struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);

	mlog_entry_void();

	buffer = la->la_bitmap;
	for (i = 0; i < le16_to_cpu(la->la_size); i++)
		count += hweight8(buffer[i]);

	mlog_exit(count);
	return count;
}

static int ocfs2_local_alloc_find_clear_bits(struct ocfs2_super *osb,
					     struct ocfs2_dinode *alloc,
					     u32 numbits)
{
	int numfound, bitoff, left, startoff, lastzero;
	void *bitmap = NULL;

	mlog_entry("(numbits wanted = %u)\n", numbits);

	if (!alloc->id1.bitmap1.i_total) {
		mlog(0, "No bits in my window!\n");
		bitoff = -1;
		goto bail;
	}

	bitmap = OCFS2_LOCAL_ALLOC(alloc)->la_bitmap;

	numfound = bitoff = startoff = 0;
	lastzero = -1;
	left = le32_to_cpu(alloc->id1.bitmap1.i_total);
	while ((bitoff = ocfs2_find_next_zero_bit(bitmap, left, startoff)) != -1) {
		if (bitoff == left) {
			/* mlog(0, "bitoff (%d) == left", bitoff); */
			break;
		}
		/* mlog(0, "Found a zero: bitoff = %d, startoff = %d, "
		   "numfound = %d\n", bitoff, startoff, numfound);*/

		/* Ok, we found a zero bit... is it contig. or do we
		 * start over?*/
		if (bitoff == startoff) {
			/* we found a zero */
			numfound++;
			startoff++;
		} else {
			/* got a zero after some ones */
			numfound = 1;
			startoff = bitoff+1;
		}
		/* we got everything we needed */
		if (numfound == numbits) {
			/* mlog(0, "Found it all!\n"); */
			break;
		}
	}

	mlog(0, "Exiting loop, bitoff = %d, numfound = %d\n", bitoff,
	     numfound);

	if (numfound == numbits)
		bitoff = startoff - numfound;
	else
		bitoff = -1;

bail:
	mlog_exit(bitoff);
	return bitoff;
}

static void ocfs2_clear_local_alloc(struct ocfs2_dinode *alloc)
{
	struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
	int i;
	mlog_entry_void();

	alloc->id1.bitmap1.i_total = 0;
	alloc->id1.bitmap1.i_used = 0;
	la->la_bm_off = 0;
	for(i = 0; i < le16_to_cpu(la->la_size); i++)
		la->la_bitmap[i] = 0;

	mlog_exit_void();
}

#if 0
/* turn this on and uncomment below to aid debugging window shifts. */
static void ocfs2_verify_zero_bits(unsigned long *bitmap,
				   unsigned int start,
				   unsigned int count)
{
	unsigned int tmp = count;
	while(tmp--) {
		if (ocfs2_test_bit(start + tmp, bitmap)) {
			printk("ocfs2_verify_zero_bits: start = %u, count = "
			       "%u\n", start, count);
			printk("ocfs2_verify_zero_bits: bit %u is set!",
			       start + tmp);
			BUG();
		}
	}
}
#endif

/*
 * sync the local alloc to main bitmap.
 *
 * assumes you've already locked the main bitmap -- the bitmap inode
 * passed is used for caching.
 */
static int ocfs2_sync_local_to_main(struct ocfs2_super *osb,
823
				    handle_t *handle,
824 825 826 827 828 829 830 831 832 833 834
				    struct ocfs2_dinode *alloc,
				    struct inode *main_bm_inode,
				    struct buffer_head *main_bm_bh)
{
	int status = 0;
	int bit_off, left, count, start;
	u64 la_start_blk;
	u64 blkno;
	void *bitmap;
	struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);

835
	mlog_entry("total = %u, used = %u\n",
836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867
		   le32_to_cpu(alloc->id1.bitmap1.i_total),
		   le32_to_cpu(alloc->id1.bitmap1.i_used));

	if (!alloc->id1.bitmap1.i_total) {
		mlog(0, "nothing to sync!\n");
		goto bail;
	}

	if (le32_to_cpu(alloc->id1.bitmap1.i_used) ==
	    le32_to_cpu(alloc->id1.bitmap1.i_total)) {
		mlog(0, "all bits were taken!\n");
		goto bail;
	}

	la_start_blk = ocfs2_clusters_to_blocks(osb->sb,
						le32_to_cpu(la->la_bm_off));
	bitmap = la->la_bitmap;
	start = count = bit_off = 0;
	left = le32_to_cpu(alloc->id1.bitmap1.i_total);

	while ((bit_off = ocfs2_find_next_zero_bit(bitmap, left, start))
	       != -1) {
		if ((bit_off < left) && (bit_off == start)) {
			count++;
			start++;
			continue;
		}
		if (count) {
			blkno = la_start_blk +
				ocfs2_clusters_to_blocks(osb->sb,
							 start - count);

868 869 870 871 872
			mlog(0, "freeing %u bits starting at local alloc bit "
			     "%u (la_start_blk = %llu, blkno = %llu)\n",
			     count, start - count,
			     (unsigned long long)la_start_blk,
			     (unsigned long long)blkno);
873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891

			status = ocfs2_free_clusters(handle, main_bm_inode,
						     main_bm_bh, blkno, count);
			if (status < 0) {
				mlog_errno(status);
				goto bail;
			}
		}
		if (bit_off >= left)
			break;
		count = 1;
		start = bit_off + 1;
	}

bail:
	mlog_exit(status);
	return status;
}

892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970
enum ocfs2_la_event {
	OCFS2_LA_EVENT_SLIDE,		/* Normal window slide. */
	OCFS2_LA_EVENT_FRAGMENTED,	/* The global bitmap has
					 * enough bits theoretically
					 * free, but a contiguous
					 * allocation could not be
					 * found. */
	OCFS2_LA_EVENT_ENOSPC,		/* Global bitmap doesn't have
					 * enough bits free to satisfy
					 * our request. */
};
#define OCFS2_LA_ENABLE_INTERVAL (30 * HZ)
/*
 * Given an event, calculate the size of our next local alloc window.
 *
 * This should always be called under i_mutex of the local alloc inode
 * so that local alloc disabling doesn't race with processes trying to
 * use the allocator.
 *
 * Returns the state which the local alloc was left in. This value can
 * be ignored by some paths.
 */
static int ocfs2_recalc_la_window(struct ocfs2_super *osb,
				  enum ocfs2_la_event event)
{
	unsigned int bits;
	int state;

	spin_lock(&osb->osb_lock);
	if (osb->local_alloc_state == OCFS2_LA_DISABLED) {
		WARN_ON_ONCE(osb->local_alloc_state == OCFS2_LA_DISABLED);
		goto out_unlock;
	}

	/*
	 * ENOSPC and fragmentation are treated similarly for now.
	 */
	if (event == OCFS2_LA_EVENT_ENOSPC ||
	    event == OCFS2_LA_EVENT_FRAGMENTED) {
		/*
		 * We ran out of contiguous space in the primary
		 * bitmap. Drastically reduce the number of bits used
		 * by local alloc until we have to disable it.
		 */
		bits = osb->local_alloc_bits >> 1;
		if (bits > ocfs2_megabytes_to_clusters(osb->sb, 1)) {
			/*
			 * By setting state to THROTTLED, we'll keep
			 * the number of local alloc bits used down
			 * until an event occurs which would give us
			 * reason to assume the bitmap situation might
			 * have changed.
			 */
			osb->local_alloc_state = OCFS2_LA_THROTTLED;
			osb->local_alloc_bits = bits;
		} else {
			osb->local_alloc_state = OCFS2_LA_DISABLED;
		}
		queue_delayed_work(ocfs2_wq, &osb->la_enable_wq,
				   OCFS2_LA_ENABLE_INTERVAL);
		goto out_unlock;
	}

	/*
	 * Don't increase the size of the local alloc window until we
	 * know we might be able to fulfill the request. Otherwise, we
	 * risk bouncing around the global bitmap during periods of
	 * low space.
	 */
	if (osb->local_alloc_state != OCFS2_LA_THROTTLED)
		osb->local_alloc_bits = osb->local_alloc_default_bits;

out_unlock:
	state = osb->local_alloc_state;
	spin_unlock(&osb->osb_lock);

	return state;
}

971 972 973 974 975 976 977
static int ocfs2_local_alloc_reserve_for_window(struct ocfs2_super *osb,
						struct ocfs2_alloc_context **ac,
						struct inode **bitmap_inode,
						struct buffer_head **bitmap_bh)
{
	int status;

978
	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
979 980 981 982 983 984
	if (!(*ac)) {
		status = -ENOMEM;
		mlog_errno(status);
		goto bail;
	}

985
retry_enospc:
986
	(*ac)->ac_bits_wanted = osb->local_alloc_bits;
987 988

	status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
989 990 991 992 993 994 995 996 997
	if (status == -ENOSPC) {
		if (ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_ENOSPC) ==
		    OCFS2_LA_DISABLED)
			goto bail;

		ocfs2_free_ac_resource(*ac);
		memset(*ac, 0, sizeof(struct ocfs2_alloc_context));
		goto retry_enospc;
	}
998
	if (status < 0) {
999
		mlog_errno(status);
1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021
		goto bail;
	}

	*bitmap_inode = (*ac)->ac_inode;
	igrab(*bitmap_inode);
	*bitmap_bh = (*ac)->ac_bh;
	get_bh(*bitmap_bh);
	status = 0;
bail:
	if ((status < 0) && *ac) {
		ocfs2_free_alloc_context(*ac);
		*ac = NULL;
	}

	mlog_exit(status);
	return status;
}

/*
 * pass it the bitmap lock in lock_bh if you have it.
 */
static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb,
1022
					handle_t *handle,
1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039
					struct ocfs2_alloc_context *ac)
{
	int status = 0;
	u32 cluster_off, cluster_count;
	struct ocfs2_dinode *alloc = NULL;
	struct ocfs2_local_alloc *la;

	mlog_entry_void();

	alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
	la = OCFS2_LOCAL_ALLOC(alloc);

	if (alloc->id1.bitmap1.i_total)
		mlog(0, "asking me to alloc a new window over a non-empty "
		     "one\n");

	mlog(0, "Allocating %u clusters for a new window.\n",
1040
	     osb->local_alloc_bits);
M
Mark Fasheh 已提交
1041 1042 1043 1044 1045 1046

	/* Instruct the allocation code to try the most recently used
	 * cluster group. We'll re-record the group used this pass
	 * below. */
	ac->ac_last_group = osb->la_last_gd;

1047 1048 1049
	/* we used the generic suballoc reserve function, but we set
	 * everything up nicely, so there's no reason why we can't use
	 * the more specific cluster api to claim bits. */
1050
	status = ocfs2_claim_clusters(osb, handle, ac, osb->local_alloc_bits,
1051
				      &cluster_off, &cluster_count);
1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079
	if (status == -ENOSPC) {
retry_enospc:
		/*
		 * Note: We could also try syncing the journal here to
		 * allow use of any free bits which the current
		 * transaction can't give us access to. --Mark
		 */
		if (ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_FRAGMENTED) ==
		    OCFS2_LA_DISABLED)
			goto bail;

		status = ocfs2_claim_clusters(osb, handle, ac,
					      osb->local_alloc_bits,
					      &cluster_off,
					      &cluster_count);
		if (status == -ENOSPC)
			goto retry_enospc;
		/*
		 * We only shrunk the *minimum* number of in our
		 * request - it's entirely possible that the allocator
		 * might give us more than we asked for.
		 */
		if (status == 0) {
			spin_lock(&osb->osb_lock);
			osb->local_alloc_bits = cluster_count;
			spin_unlock(&osb->osb_lock);
		}
	}
1080 1081 1082 1083 1084 1085
	if (status < 0) {
		if (status != -ENOSPC)
			mlog_errno(status);
		goto bail;
	}

M
Mark Fasheh 已提交
1086 1087
	osb->la_last_gd = ac->ac_last_group;

1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115
	la->la_bm_off = cpu_to_le32(cluster_off);
	alloc->id1.bitmap1.i_total = cpu_to_le32(cluster_count);
	/* just in case... In the future when we find space ourselves,
	 * we don't have to get all contiguous -- but we'll have to
	 * set all previously used bits in bitmap and update
	 * la_bits_set before setting the bits in the main bitmap. */
	alloc->id1.bitmap1.i_used = 0;
	memset(OCFS2_LOCAL_ALLOC(alloc)->la_bitmap, 0,
	       le16_to_cpu(la->la_size));

	mlog(0, "New window allocated:\n");
	mlog(0, "window la_bm_off = %u\n",
	     OCFS2_LOCAL_ALLOC(alloc)->la_bm_off);
	mlog(0, "window bits = %u\n", le32_to_cpu(alloc->id1.bitmap1.i_total));

bail:
	mlog_exit(status);
	return status;
}

/* Note that we do *NOT* lock the local alloc inode here as
 * it's been locked already for us. */
static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb,
					  struct inode *local_alloc_inode)
{
	int status = 0;
	struct buffer_head *main_bm_bh = NULL;
	struct inode *main_bm_inode = NULL;
1116
	handle_t *handle = NULL;
1117 1118 1119 1120 1121 1122
	struct ocfs2_dinode *alloc;
	struct ocfs2_dinode *alloc_copy = NULL;
	struct ocfs2_alloc_context *ac = NULL;

	mlog_entry_void();

1123 1124
	ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_SLIDE);

1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135
	/* This will lock the main bitmap for us. */
	status = ocfs2_local_alloc_reserve_for_window(osb,
						      &ac,
						      &main_bm_inode,
						      &main_bm_bh);
	if (status < 0) {
		if (status != -ENOSPC)
			mlog_errno(status);
		goto bail;
	}

1136
	handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150
	if (IS_ERR(handle)) {
		status = PTR_ERR(handle);
		handle = NULL;
		mlog_errno(status);
		goto bail;
	}

	alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;

	/* We want to clear the local alloc before doing anything
	 * else, so that if we error later during this operation,
	 * local alloc shutdown won't try to double free main bitmap
	 * bits. Make a copy so the sync function knows which bits to
	 * free. */
1151
	alloc_copy = kmalloc(osb->local_alloc_bh->b_size, GFP_NOFS);
1152 1153 1154 1155 1156 1157 1158
	if (!alloc_copy) {
		status = -ENOMEM;
		mlog_errno(status);
		goto bail;
	}
	memcpy(alloc_copy, alloc, osb->local_alloc_bh->b_size);

1159 1160 1161
	status = ocfs2_journal_access_di(handle, local_alloc_inode,
					 osb->local_alloc_bh,
					 OCFS2_JOURNAL_ACCESS_WRITE);
1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	ocfs2_clear_local_alloc(alloc);

	status = ocfs2_journal_dirty(handle, osb->local_alloc_bh);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	status = ocfs2_sync_local_to_main(osb, handle, alloc_copy,
					  main_bm_inode, main_bm_bh);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	status = ocfs2_local_alloc_new_window(osb, handle, ac);
	if (status < 0) {
		if (status != -ENOSPC)
			mlog_errno(status);
		goto bail;
	}

	atomic_inc(&osb->alloc_stats.moves);

	status = 0;
bail:
	if (handle)
1194
		ocfs2_commit_trans(osb, handle);
1195

1196
	brelse(main_bm_bh);
1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210

	if (main_bm_inode)
		iput(main_bm_inode);

	if (alloc_copy)
		kfree(alloc_copy);

	if (ac)
		ocfs2_free_alloc_context(ac);

	mlog_exit(status);
	return status;
}