localalloc.c

linux 内核源代码

/* -*- 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"
#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 inline int ocfs2_local_alloc_window_bits(struct ocfs2_super *osb);

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,
				    handle_t *handle,
				    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,
					handle_t *handle,
					struct ocfs2_alloc_context *ac);

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

/*
 * Determine how large our local alloc window should be, in bits.
 *
 * These values (and the behavior in ocfs2_alloc_should_use_local) have
 * been chosen so that most allocations, including new block groups go
 * through local alloc.
 */
static inline int ocfs2_local_alloc_window_bits(struct ocfs2_super *osb)
{
	BUG_ON(osb->s_clustersize_bits < 12);

	return 2048 >> (osb->s_clustersize_bits - 12);
}

/*
 * Tell us whether a given allocation should use the local alloc
 * file. Otherwise, it has to go to the main bitmap.
 */
int ocfs2_alloc_should_use_local(struct ocfs2_super *osb, u64 bits)
{
	int la_bits = ocfs2_local_alloc_window_bits(osb);

	if (osb->local_alloc_state != OCFS2_LA_ENABLED)
		return 0;

	/* 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))
		return 0;

	return 1;
}

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();

	/* 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;
	}

	status = ocfs2_read_block(osb, OCFS2_I(inode)->ip_blkno,
				  &alloc_bh, 0, inode);
	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))) {
		mlog(ML_ERROR, "Invalid local alloc inode, %llu\n",
		     (unsigned long long)OCFS2_I(inode)->ip_blkno);
		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)
		if (alloc_bh)
			brelse(alloc_bh);
	if (inode)
		iput(inode);

	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;
	handle_t *handle;
	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();

	if (osb->local_alloc_state == OCFS2_LA_UNUSED)
		goto out;

	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 out;
	}

	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);
		goto out;
	}

	mutex_lock(&main_bm_inode->i_mutex);

	status = ocfs2_meta_lock(main_bm_inode, &main_bm_bh, 1);
	if (status < 0) {
		mlog_errno(status);
		goto out_mutex;
	}

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

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

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

	status = ocfs2_journal_access(handle, local_alloc_inode, bh,
				      OCFS2_JOURNAL_ACCESS_WRITE);
	if (status < 0) {
		mlog_errno(status);
		goto out_commit;
	}

	ocfs2_clear_local_alloc(alloc);

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

	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);

out_commit:
	ocfs2_commit_trans(osb, handle);

out_unlock:
	if (main_bm_bh)
		brelse(main_bm_bh);

	ocfs2_meta_unlock(main_bm_inode, 1);

out_mutex:
	mutex_unlock(&main_bm_inode->i_mutex);
	iput(main_bm_inode);

out:
	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;
	}

	mutex_lock(&inode->i_mutex);

	status = ocfs2_read_block(osb, OCFS2_I(inode)->ip_blkno,
				  &alloc_bh, 0, inode);
	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);

	status = ocfs2_write_block(osb, alloc_bh, inode);
	if (status < 0)
		mlog_errno(status);

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

	if (alloc_bh)
		brelse(alloc_bh);

	if (inode) {
		mutex_unlock(&inode->i_mutex);
		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;
	handle_t *handle;
	struct buffer_head *main_bm_bh = NULL;
	struct inode *main_bm_inode;

	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);
		goto out;
	}

	mutex_lock(&main_bm_inode->i_mutex);

	status = ocfs2_meta_lock(main_bm_inode, &main_bm_bh, 1);
	if (status < 0) {
		mlog_errno(status);
		goto out_mutex;
	}

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

	/* we want the bitmap change to be recorded on disk asap */
	handle->h_sync = 1;

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

	ocfs2_commit_trans(osb, handle);

out_unlock:
	ocfs2_meta_unlock(main_bm_inode, 1);

out_mutex:
	mutex_unlock(&main_bm_inode->i_mutex);

	if (main_bm_bh)
		brelse(main_bm_bh);

	iput(main_bm_inode);

out:
	mlog_exit(status);
	return status;
}

/*
 * make sure we've got at least bitswanted contiguous bits in the
 * local alloc. You lose them when you drop i_mutex.
 *
 * 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;
	}

	mutex_lock(&local_alloc_inode->i_mutex);

	if (osb->local_alloc_state != OCFS2_LA_ENABLED) {
		status = -ENOSPC;
		goto bail;
	}

	if (bits_wanted > ocfs2_local_alloc_window_bits(osb)) {
		mlog(0, "Asking for more than my max window size!\n");
		status = -ENOSPC;
		goto bail;
	}

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

#ifdef OCFS2_DEBUG_FS
	if (le32_to_cpu(alloc->id1.bitmap1.i_used) !=
	    ocfs2_local_alloc_count_bits(alloc)) {