resize.c 50.3 KB
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/*
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 *  linux/fs/ext4/resize.c
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 *
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 * Support for resizing an ext4 filesystem while it is mounted.
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 *
 * Copyright (C) 2001, 2002 Andreas Dilger <adilger@clusterfs.com>
 *
 * This could probably be made into a module, because it is not often in use.
 */


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#define EXT4FS_DEBUG
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#include <linux/errno.h>
#include <linux/slab.h>

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#include "ext4_jbd2.h"
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int ext4_resize_begin(struct super_block *sb)
{
	int ret = 0;

	if (!capable(CAP_SYS_RESOURCE))
		return -EPERM;

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	/*
	 * We are not allowed to do online-resizing on a filesystem mounted
	 * with error, because it can destroy the filesystem easily.
	 */
	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
		ext4_warning(sb, "There are errors in the filesystem, "
			     "so online resizing is not allowed\n");
		return -EPERM;
	}

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	if (test_and_set_bit_lock(EXT4_RESIZING, &EXT4_SB(sb)->s_resize_flags))
		ret = -EBUSY;

	return ret;
}

void ext4_resize_end(struct super_block *sb)
{
	clear_bit_unlock(EXT4_RESIZING, &EXT4_SB(sb)->s_resize_flags);
	smp_mb__after_clear_bit();
}

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#define outside(b, first, last)	((b) < (first) || (b) >= (last))
#define inside(b, first, last)	((b) >= (first) && (b) < (last))

static int verify_group_input(struct super_block *sb,
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			      struct ext4_new_group_data *input)
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{
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	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_super_block *es = sbi->s_es;
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Laurent Vivier 已提交
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	ext4_fsblk_t start = ext4_blocks_count(es);
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	ext4_fsblk_t end = start + input->blocks_count;
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	ext4_group_t group = input->group;
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	ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group;
	unsigned overhead = ext4_bg_has_super(sb, group) ?
		(1 + ext4_bg_num_gdb(sb, group) +
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		 le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
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	ext4_fsblk_t metaend = start + overhead;
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	struct buffer_head *bh = NULL;
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	ext4_grpblk_t free_blocks_count, offset;
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	int err = -EINVAL;

	input->free_blocks_count = free_blocks_count =
		input->blocks_count - 2 - overhead - sbi->s_itb_per_group;

	if (test_opt(sb, DEBUG))
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		printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks "
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		       "(%d free, %u reserved)\n",
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		       ext4_bg_has_super(sb, input->group) ? "normal" :
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		       "no-super", input->group, input->blocks_count,
		       free_blocks_count, input->reserved_blocks);

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	ext4_get_group_no_and_offset(sb, start, NULL, &offset);
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	if (group != sbi->s_groups_count)
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		ext4_warning(sb, "Cannot add at group %u (only %u groups)",
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			     input->group, sbi->s_groups_count);
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	else if (offset != 0)
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			ext4_warning(sb, "Last group not full");
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	else if (input->reserved_blocks > input->blocks_count / 5)
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		ext4_warning(sb, "Reserved blocks too high (%u)",
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			     input->reserved_blocks);
	else if (free_blocks_count < 0)
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		ext4_warning(sb, "Bad blocks count %u",
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			     input->blocks_count);
	else if (!(bh = sb_bread(sb, end - 1)))
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		ext4_warning(sb, "Cannot read last block (%llu)",
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			     end - 1);
	else if (outside(input->block_bitmap, start, end))
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		ext4_warning(sb, "Block bitmap not in group (block %llu)",
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			     (unsigned long long)input->block_bitmap);
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	else if (outside(input->inode_bitmap, start, end))
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		ext4_warning(sb, "Inode bitmap not in group (block %llu)",
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			     (unsigned long long)input->inode_bitmap);
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	else if (outside(input->inode_table, start, end) ||
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		 outside(itend - 1, start, end))
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		ext4_warning(sb, "Inode table not in group (blocks %llu-%llu)",
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			     (unsigned long long)input->inode_table, itend - 1);
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	else if (input->inode_bitmap == input->block_bitmap)
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		ext4_warning(sb, "Block bitmap same as inode bitmap (%llu)",
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			     (unsigned long long)input->block_bitmap);
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	else if (inside(input->block_bitmap, input->inode_table, itend))
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		ext4_warning(sb, "Block bitmap (%llu) in inode table "
			     "(%llu-%llu)",
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			     (unsigned long long)input->block_bitmap,
			     (unsigned long long)input->inode_table, itend - 1);
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	else if (inside(input->inode_bitmap, input->inode_table, itend))
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		ext4_warning(sb, "Inode bitmap (%llu) in inode table "
			     "(%llu-%llu)",
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			     (unsigned long long)input->inode_bitmap,
			     (unsigned long long)input->inode_table, itend - 1);
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	else if (inside(input->block_bitmap, start, metaend))
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		ext4_warning(sb, "Block bitmap (%llu) in GDT table (%llu-%llu)",
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			     (unsigned long long)input->block_bitmap,
			     start, metaend - 1);
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	else if (inside(input->inode_bitmap, start, metaend))
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		ext4_warning(sb, "Inode bitmap (%llu) in GDT table (%llu-%llu)",
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			     (unsigned long long)input->inode_bitmap,
			     start, metaend - 1);
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	else if (inside(input->inode_table, start, metaend) ||
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		 inside(itend - 1, start, metaend))
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		ext4_warning(sb, "Inode table (%llu-%llu) overlaps GDT table "
			     "(%llu-%llu)",
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			     (unsigned long long)input->inode_table,
			     itend - 1, start, metaend - 1);
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	else
		err = 0;
	brelse(bh);

	return err;
}

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/*
 * ext4_new_flex_group_data is used by 64bit-resize interface to add a flex
 * group each time.
 */
struct ext4_new_flex_group_data {
	struct ext4_new_group_data *groups;	/* new_group_data for groups
						   in the flex group */
	__u16 *bg_flags;			/* block group flags of groups
						   in @groups */
	ext4_group_t count;			/* number of groups in @groups
						 */
};

/*
 * alloc_flex_gd() allocates a ext4_new_flex_group_data with size of
 * @flexbg_size.
 *
 * Returns NULL on failure otherwise address of the allocated structure.
 */
static struct ext4_new_flex_group_data *alloc_flex_gd(unsigned long flexbg_size)
{
	struct ext4_new_flex_group_data *flex_gd;

	flex_gd = kmalloc(sizeof(*flex_gd), GFP_NOFS);
	if (flex_gd == NULL)
		goto out3;

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	if (flexbg_size >= UINT_MAX / sizeof(struct ext4_new_flex_group_data))
		goto out2;
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	flex_gd->count = flexbg_size;

	flex_gd->groups = kmalloc(sizeof(struct ext4_new_group_data) *
				  flexbg_size, GFP_NOFS);
	if (flex_gd->groups == NULL)
		goto out2;

	flex_gd->bg_flags = kmalloc(flexbg_size * sizeof(__u16), GFP_NOFS);
	if (flex_gd->bg_flags == NULL)
		goto out1;

	return flex_gd;

out1:
	kfree(flex_gd->groups);
out2:
	kfree(flex_gd);
out3:
	return NULL;
}

static void free_flex_gd(struct ext4_new_flex_group_data *flex_gd)
{
	kfree(flex_gd->bg_flags);
	kfree(flex_gd->groups);
	kfree(flex_gd);
}

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/*
 * ext4_alloc_group_tables() allocates block bitmaps, inode bitmaps
 * and inode tables for a flex group.
 *
 * This function is used by 64bit-resize.  Note that this function allocates
 * group tables from the 1st group of groups contained by @flexgd, which may
 * be a partial of a flex group.
 *
 * @sb: super block of fs to which the groups belongs
 */
static void ext4_alloc_group_tables(struct super_block *sb,
				struct ext4_new_flex_group_data *flex_gd,
				int flexbg_size)
{
	struct ext4_new_group_data *group_data = flex_gd->groups;
	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
	ext4_fsblk_t start_blk;
	ext4_fsblk_t last_blk;
	ext4_group_t src_group;
	ext4_group_t bb_index = 0;
	ext4_group_t ib_index = 0;
	ext4_group_t it_index = 0;
	ext4_group_t group;
	ext4_group_t last_group;
	unsigned overhead;

	BUG_ON(flex_gd->count == 0 || group_data == NULL);

	src_group = group_data[0].group;
	last_group  = src_group + flex_gd->count - 1;

	BUG_ON((flexbg_size > 1) && ((src_group & ~(flexbg_size - 1)) !=
	       (last_group & ~(flexbg_size - 1))));
next_group:
	group = group_data[0].group;
	start_blk = ext4_group_first_block_no(sb, src_group);
	last_blk = start_blk + group_data[src_group - group].blocks_count;

	overhead = ext4_bg_has_super(sb, src_group) ?
		   (1 + ext4_bg_num_gdb(sb, src_group) +
		    le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;

	start_blk += overhead;

	BUG_ON(src_group >= group_data[0].group + flex_gd->count);
	/* We collect contiguous blocks as much as possible. */
	src_group++;
	for (; src_group <= last_group; src_group++)
		if (!ext4_bg_has_super(sb, src_group))
			last_blk += group_data[src_group - group].blocks_count;
		else
			break;

	/* Allocate block bitmaps */
	for (; bb_index < flex_gd->count; bb_index++) {
		if (start_blk >= last_blk)
			goto next_group;
		group_data[bb_index].block_bitmap = start_blk++;
		ext4_get_group_no_and_offset(sb, start_blk - 1, &group, NULL);
		group -= group_data[0].group;
		group_data[group].free_blocks_count--;
		if (flexbg_size > 1)
			flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT;
	}

	/* Allocate inode bitmaps */
	for (; ib_index < flex_gd->count; ib_index++) {
		if (start_blk >= last_blk)
			goto next_group;
		group_data[ib_index].inode_bitmap = start_blk++;
		ext4_get_group_no_and_offset(sb, start_blk - 1, &group, NULL);
		group -= group_data[0].group;
		group_data[group].free_blocks_count--;
		if (flexbg_size > 1)
			flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT;
	}

	/* Allocate inode tables */
	for (; it_index < flex_gd->count; it_index++) {
		if (start_blk + EXT4_SB(sb)->s_itb_per_group > last_blk)
			goto next_group;
		group_data[it_index].inode_table = start_blk;
		ext4_get_group_no_and_offset(sb, start_blk, &group, NULL);
		group -= group_data[0].group;
		group_data[group].free_blocks_count -=
					EXT4_SB(sb)->s_itb_per_group;
		if (flexbg_size > 1)
			flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT;

		start_blk += EXT4_SB(sb)->s_itb_per_group;
	}

	if (test_opt(sb, DEBUG)) {
		int i;
		group = group_data[0].group;

		printk(KERN_DEBUG "EXT4-fs: adding a flex group with "
		       "%d groups, flexbg size is %d:\n", flex_gd->count,
		       flexbg_size);

		for (i = 0; i < flex_gd->count; i++) {
			printk(KERN_DEBUG "adding %s group %u: %u "
			       "blocks (%d free)\n",
			       ext4_bg_has_super(sb, group + i) ? "normal" :
			       "no-super", group + i,
			       group_data[i].blocks_count,
			       group_data[i].free_blocks_count);
		}
	}
}

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static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
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				  ext4_fsblk_t blk)
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{
	struct buffer_head *bh;
	int err;

	bh = sb_getblk(sb, blk);
	if (!bh)
		return ERR_PTR(-EIO);
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	if ((err = ext4_journal_get_write_access(handle, bh))) {
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		brelse(bh);
		bh = ERR_PTR(err);
	} else {
		memset(bh->b_data, 0, sb->s_blocksize);
		set_buffer_uptodate(bh);
	}

	return bh;
}

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/*
 * If we have fewer than thresh credits, extend by EXT4_MAX_TRANS_DATA.
 * If that fails, restart the transaction & regain write access for the
 * buffer head which is used for block_bitmap modifications.
 */
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static int extend_or_restart_transaction(handle_t *handle, int thresh)
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{
	int err;

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	if (ext4_handle_has_enough_credits(handle, thresh))
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		return 0;

	err = ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA);
	if (err < 0)
		return err;
	if (err) {
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		err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA);
		if (err)
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			return err;
344
	}
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	return 0;
}

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/*
 * set_flexbg_block_bitmap() mark @count blocks starting from @block used.
 *
 * Helper function for ext4_setup_new_group_blocks() which set .
 *
 * @sb: super block
 * @handle: journal handle
 * @flex_gd: flex group data
 */
static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle,
			struct ext4_new_flex_group_data *flex_gd,
			ext4_fsblk_t block, ext4_group_t count)
{
	ext4_group_t count2;

	ext4_debug("mark blocks [%llu/%u] used\n", block, count);
	for (count2 = count; count > 0; count -= count2, block += count2) {
		ext4_fsblk_t start;
		struct buffer_head *bh;
		ext4_group_t group;
		int err;

		ext4_get_group_no_and_offset(sb, block, &group, NULL);
		start = ext4_group_first_block_no(sb, group);
		group -= flex_gd->groups[0].group;

		count2 = sb->s_blocksize * 8 - (block - start);
		if (count2 > count)
			count2 = count;

		if (flex_gd->bg_flags[group] & EXT4_BG_BLOCK_UNINIT) {
			BUG_ON(flex_gd->count > 1);
			continue;
		}

		err = extend_or_restart_transaction(handle, 1);
		if (err)
			return err;

		bh = sb_getblk(sb, flex_gd->groups[group].block_bitmap);
		if (!bh)
			return -EIO;

		err = ext4_journal_get_write_access(handle, bh);
		if (err)
			return err;
		ext4_debug("mark block bitmap %#04llx (+%llu/%u)\n", block,
			   block - start, count2);
		ext4_set_bits(bh->b_data, block - start, count2);

		err = ext4_handle_dirty_metadata(handle, NULL, bh);
		if (unlikely(err))
			return err;
		brelse(bh);
	}

	return 0;
}

/*
 * Set up the block and inode bitmaps, and the inode table for the new groups.
 * This doesn't need to be part of the main transaction, since we are only
 * changing blocks outside the actual filesystem.  We still do journaling to
 * ensure the recovery is correct in case of a failure just after resize.
 * If any part of this fails, we simply abort the resize.
 *
 * setup_new_flex_group_blocks handles a flex group as follow:
 *  1. copy super block and GDT, and initialize group tables if necessary.
 *     In this step, we only set bits in blocks bitmaps for blocks taken by
 *     super block and GDT.
 *  2. allocate group tables in block bitmaps, that is, set bits in block
 *     bitmap for blocks taken by group tables.
 */
static int setup_new_flex_group_blocks(struct super_block *sb,
				struct ext4_new_flex_group_data *flex_gd)
{
	int group_table_count[] = {1, 1, EXT4_SB(sb)->s_itb_per_group};
	ext4_fsblk_t start;
	ext4_fsblk_t block;
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_super_block *es = sbi->s_es;
	struct ext4_new_group_data *group_data = flex_gd->groups;
	__u16 *bg_flags = flex_gd->bg_flags;
	handle_t *handle;
	ext4_group_t group, count;
	struct buffer_head *bh = NULL;
	int reserved_gdb, i, j, err = 0, err2;

	BUG_ON(!flex_gd->count || !group_data ||
	       group_data[0].group != sbi->s_groups_count);

	reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks);

	/* This transaction may be extended/restarted along the way */
	handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA);
	if (IS_ERR(handle))
		return PTR_ERR(handle);

	group = group_data[0].group;
	for (i = 0; i < flex_gd->count; i++, group++) {
		unsigned long gdblocks;

		gdblocks = ext4_bg_num_gdb(sb, group);
		start = ext4_group_first_block_no(sb, group);

		/* Copy all of the GDT blocks into the backup in this group */
		for (j = 0, block = start + 1; j < gdblocks; j++, block++) {
			struct buffer_head *gdb;

			ext4_debug("update backup group %#04llx\n", block);
			err = extend_or_restart_transaction(handle, 1);
			if (err)
				goto out;

			gdb = sb_getblk(sb, block);
			if (!gdb) {
				err = -EIO;
				goto out;
			}

			err = ext4_journal_get_write_access(handle, gdb);
			if (err) {
				brelse(gdb);
				goto out;
			}
			memcpy(gdb->b_data, sbi->s_group_desc[j]->b_data,
			       gdb->b_size);
			set_buffer_uptodate(gdb);

			err = ext4_handle_dirty_metadata(handle, NULL, gdb);
			if (unlikely(err)) {
				brelse(gdb);
				goto out;
			}
			brelse(gdb);
		}

		/* Zero out all of the reserved backup group descriptor
		 * table blocks
		 */
		if (ext4_bg_has_super(sb, group)) {
			err = sb_issue_zeroout(sb, gdblocks + start + 1,
					reserved_gdb, GFP_NOFS);
			if (err)
				goto out;
		}

		/* Initialize group tables of the grop @group */
		if (!(bg_flags[i] & EXT4_BG_INODE_ZEROED))
			goto handle_bb;

		/* Zero out all of the inode table blocks */
		block = group_data[i].inode_table;
		ext4_debug("clear inode table blocks %#04llx -> %#04lx\n",
			   block, sbi->s_itb_per_group);
		err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group,
				       GFP_NOFS);
		if (err)
			goto out;

handle_bb:
		if (bg_flags[i] & EXT4_BG_BLOCK_UNINIT)
			goto handle_ib;

		/* Initialize block bitmap of the @group */
		block = group_data[i].block_bitmap;
		err = extend_or_restart_transaction(handle, 1);
		if (err)
			goto out;

		bh = bclean(handle, sb, block);
		if (IS_ERR(bh)) {
			err = PTR_ERR(bh);
			goto out;
		}
		if (ext4_bg_has_super(sb, group)) {
			ext4_debug("mark backup superblock %#04llx (+0)\n",
				   start);
			ext4_set_bits(bh->b_data, 0, gdblocks + reserved_gdb +
						     1);
		}
		ext4_mark_bitmap_end(group_data[i].blocks_count,
				     sb->s_blocksize * 8, bh->b_data);
		err = ext4_handle_dirty_metadata(handle, NULL, bh);
		if (err)
			goto out;
		brelse(bh);

handle_ib:
		if (bg_flags[i] & EXT4_BG_INODE_UNINIT)
			continue;

		/* Initialize inode bitmap of the @group */
		block = group_data[i].inode_bitmap;
		err = extend_or_restart_transaction(handle, 1);
		if (err)
			goto out;
		/* Mark unused entries in inode bitmap used */
		bh = bclean(handle, sb, block);
		if (IS_ERR(bh)) {
			err = PTR_ERR(bh);
			goto out;
		}

		ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
				     sb->s_blocksize * 8, bh->b_data);
		err = ext4_handle_dirty_metadata(handle, NULL, bh);
		if (err)
			goto out;
		brelse(bh);
	}
	bh = NULL;

	/* Mark group tables in block bitmap */
	for (j = 0; j < GROUP_TABLE_COUNT; j++) {
		count = group_table_count[j];
		start = (&group_data[0].block_bitmap)[j];
		block = start;
		for (i = 1; i < flex_gd->count; i++) {
			block += group_table_count[j];
			if (block == (&group_data[i].block_bitmap)[j]) {
				count += group_table_count[j];
				continue;
			}
			err = set_flexbg_block_bitmap(sb, handle,
						flex_gd, start, count);
			if (err)
				goto out;
			count = group_table_count[j];
			start = group_data[i].block_bitmap;
			block = start;
		}

		if (count) {
			err = set_flexbg_block_bitmap(sb, handle,
						flex_gd, start, count);
			if (err)
				goto out;
		}
	}

out:
	brelse(bh);
	err2 = ext4_journal_stop(handle);
	if (err2 && !err)
		err = err2;

	return err;
}

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/*
 * Iterate through the groups which hold BACKUP superblock/GDT copies in an
601
 * ext4 filesystem.  The counters should be initialized to 1, 5, and 7 before
602 603 604 605
 * calling this for the first time.  In a sparse filesystem it will be the
 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
 */
606
static unsigned ext4_list_backups(struct super_block *sb, unsigned *three,
607 608 609 610 611 612
				  unsigned *five, unsigned *seven)
{
	unsigned *min = three;
	int mult = 3;
	unsigned ret;

613 614
	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
					EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640
		ret = *min;
		*min += 1;
		return ret;
	}

	if (*five < *min) {
		min = five;
		mult = 5;
	}
	if (*seven < *min) {
		min = seven;
		mult = 7;
	}

	ret = *min;
	*min *= mult;

	return ret;
}

/*
 * Check that all of the backup GDT blocks are held in the primary GDT block.
 * It is assumed that they are stored in group order.  Returns the number of
 * groups in current filesystem that have BACKUPS, or -ve error code.
 */
static int verify_reserved_gdb(struct super_block *sb,
641
			       ext4_group_t end,
642 643
			       struct buffer_head *primary)
{
644
	const ext4_fsblk_t blk = primary->b_blocknr;
645 646 647 648 649 650 651
	unsigned three = 1;
	unsigned five = 5;
	unsigned seven = 7;
	unsigned grp;
	__le32 *p = (__le32 *)primary->b_data;
	int gdbackups = 0;

652
	while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) {
L
Laurent Vivier 已提交
653 654
		if (le32_to_cpu(*p++) !=
		    grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){
655
			ext4_warning(sb, "reserved GDT %llu"
656
				     " missing grp %d (%llu)",
657
				     blk, grp,
L
Laurent Vivier 已提交
658 659 660
				     grp *
				     (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
				     blk);
661 662
			return -EINVAL;
		}
663
		if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb))
664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683
			return -EFBIG;
	}

	return gdbackups;
}

/*
 * Called when we need to bring a reserved group descriptor table block into
 * use from the resize inode.  The primary copy of the new GDT block currently
 * is an indirect block (under the double indirect block in the resize inode).
 * The new backup GDT blocks will be stored as leaf blocks in this indirect
 * block, in group order.  Even though we know all the block numbers we need,
 * we check to ensure that the resize inode has actually reserved these blocks.
 *
 * Don't need to update the block bitmaps because the blocks are still in use.
 *
 * We get all of the error cases out of the way, so that we are sure to not
 * fail once we start modifying the data on disk, because JBD has no rollback.
 */
static int add_new_gdb(handle_t *handle, struct inode *inode,
684
		       ext4_group_t group)
685 686
{
	struct super_block *sb = inode->i_sb;
687
	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
688
	unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
689
	ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num;
690 691
	struct buffer_head **o_group_desc, **n_group_desc;
	struct buffer_head *dind;
692
	struct buffer_head *gdb_bh;
693
	int gdbackups;
694
	struct ext4_iloc iloc;
695 696 697 698 699
	__le32 *data;
	int err;

	if (test_opt(sb, DEBUG))
		printk(KERN_DEBUG
700
		       "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n",
701 702
		       gdb_num);

703 704
	/*
	 * If we are not using the primary superblock/GDT copy don't resize,
705 706 707
         * because the user tools have no way of handling this.  Probably a
         * bad time to do it anyways.
         */
708 709
	if (EXT4_SB(sb)->s_sbh->b_blocknr !=
	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
710
		ext4_warning(sb, "won't resize using backup superblock at %llu",
711
			(unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr);
712 713 714
		return -EPERM;
	}

715 716
	gdb_bh = sb_bread(sb, gdblock);
	if (!gdb_bh)
717 718
		return -EIO;

719
	gdbackups = verify_reserved_gdb(sb, group, gdb_bh);
720
	if (gdbackups < 0) {
721 722 723 724
		err = gdbackups;
		goto exit_bh;
	}

725
	data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
726 727 728 729 730 731 732
	dind = sb_bread(sb, le32_to_cpu(*data));
	if (!dind) {
		err = -EIO;
		goto exit_bh;
	}

	data = (__le32 *)dind->b_data;
733
	if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) {
734
		ext4_warning(sb, "new group %u GDT block %llu not reserved",
735
			     group, gdblock);
736 737 738 739
		err = -EINVAL;
		goto exit_dind;
	}

740 741
	err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
	if (unlikely(err))
742 743
		goto exit_dind;

744
	err = ext4_journal_get_write_access(handle, gdb_bh);
745
	if (unlikely(err))
746 747
		goto exit_sbh;

748 749 750
	err = ext4_journal_get_write_access(handle, dind);
	if (unlikely(err))
		ext4_std_error(sb, err);
751

752
	/* ext4_reserve_inode_write() gets a reference on the iloc */
753 754
	err = ext4_reserve_inode_write(handle, inode, &iloc);
	if (unlikely(err))
755 756
		goto exit_dindj;

757 758 759
	n_group_desc = ext4_kvmalloc((gdb_num + 1) *
				     sizeof(struct buffer_head *),
				     GFP_NOFS);
760 761
	if (!n_group_desc) {
		err = -ENOMEM;
762 763
		ext4_warning(sb, "not enough memory for %lu groups",
			     gdb_num + 1);
764 765 766 767 768 769 770 771 772 773 774 775
		goto exit_inode;
	}

	/*
	 * Finally, we have all of the possible failures behind us...
	 *
	 * Remove new GDT block from inode double-indirect block and clear out
	 * the new GDT block for use (which also "frees" the backup GDT blocks
	 * from the reserved inode).  We don't need to change the bitmaps for
	 * these blocks, because they are marked as in-use from being in the
	 * reserved inode, and will become GDT blocks (primary and backup).
	 */
776
	data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0;
777 778 779 780 781
	err = ext4_handle_dirty_metadata(handle, NULL, dind);
	if (unlikely(err)) {
		ext4_std_error(sb, err);
		goto exit_inode;
	}
782
	inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 9;
783
	ext4_mark_iloc_dirty(handle, inode, &iloc);
784 785
	memset(gdb_bh->b_data, 0, sb->s_blocksize);
	err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
786 787 788 789 790
	if (unlikely(err)) {
		ext4_std_error(sb, err);
		goto exit_inode;
	}
	brelse(dind);
791

792
	o_group_desc = EXT4_SB(sb)->s_group_desc;
793
	memcpy(n_group_desc, o_group_desc,
794
	       EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
795
	n_group_desc[gdb_num] = gdb_bh;
796 797
	EXT4_SB(sb)->s_group_desc = n_group_desc;
	EXT4_SB(sb)->s_gdb_count++;
798
	ext4_kvfree(o_group_desc);
799

M
Marcin Slusarz 已提交
800
	le16_add_cpu(&es->s_reserved_gdt_blocks, -1);
801
	err = ext4_handle_dirty_super_now(handle, sb);
802 803
	if (err)
		ext4_std_error(sb, err);
804

805
	return err;
806 807

exit_inode:
808
	ext4_kvfree(n_group_desc);
809
	/* ext4_handle_release_buffer(handle, iloc.bh); */
810 811
	brelse(iloc.bh);
exit_dindj:
812
	/* ext4_handle_release_buffer(handle, dind); */
813
exit_sbh:
814
	/* ext4_handle_release_buffer(handle, EXT4_SB(sb)->s_sbh); */
815 816 817
exit_dind:
	brelse(dind);
exit_bh:
818
	brelse(gdb_bh);
819

820
	ext4_debug("leaving with error %d\n", err);
821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837
	return err;
}

/*
 * Called when we are adding a new group which has a backup copy of each of
 * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks.
 * We need to add these reserved backup GDT blocks to the resize inode, so
 * that they are kept for future resizing and not allocated to files.
 *
 * Each reserved backup GDT block will go into a different indirect block.
 * The indirect blocks are actually the primary reserved GDT blocks,
 * so we know in advance what their block numbers are.  We only get the
 * double-indirect block to verify it is pointing to the primary reserved
 * GDT blocks so we don't overwrite a data block by accident.  The reserved
 * backup GDT blocks are stored in their reserved primary GDT block.
 */
static int reserve_backup_gdb(handle_t *handle, struct inode *inode,
838
			      ext4_group_t group)
839 840
{
	struct super_block *sb = inode->i_sb;
841
	int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
842 843
	struct buffer_head **primary;
	struct buffer_head *dind;
844 845
	struct ext4_iloc iloc;
	ext4_fsblk_t blk;
846 847 848 849 850
	__le32 *data, *end;
	int gdbackups = 0;
	int res, i;
	int err;

851
	primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_NOFS);
852 853 854
	if (!primary)
		return -ENOMEM;

855
	data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
856 857 858 859 860 861
	dind = sb_bread(sb, le32_to_cpu(*data));
	if (!dind) {
		err = -EIO;
		goto exit_free;
	}

862
	blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count;
J
Josef Bacik 已提交
863 864
	data = (__le32 *)dind->b_data + (EXT4_SB(sb)->s_gdb_count %
					 EXT4_ADDR_PER_BLOCK(sb));
865
	end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb);
866 867 868 869

	/* Get each reserved primary GDT block and verify it holds backups */
	for (res = 0; res < reserved_gdb; res++, blk++) {
		if (le32_to_cpu(*data) != blk) {
870
			ext4_warning(sb, "reserved block %llu"
871 872 873 874 875 876 877 878 879 880 881
				     " not at offset %ld",
				     blk,
				     (long)(data - (__le32 *)dind->b_data));
			err = -EINVAL;
			goto exit_bh;
		}
		primary[res] = sb_bread(sb, blk);
		if (!primary[res]) {
			err = -EIO;
			goto exit_bh;
		}
882 883
		gdbackups = verify_reserved_gdb(sb, group, primary[res]);
		if (gdbackups < 0) {
884 885 886 887 888 889 890 891 892
			brelse(primary[res]);
			err = gdbackups;
			goto exit_bh;
		}
		if (++data >= end)
			data = (__le32 *)dind->b_data;
	}

	for (i = 0; i < reserved_gdb; i++) {
893
		if ((err = ext4_journal_get_write_access(handle, primary[i]))) {
894 895 896
			/*
			int j;
			for (j = 0; j < i; j++)
897
				ext4_handle_release_buffer(handle, primary[j]);
898 899 900 901 902
			 */
			goto exit_bh;
		}
	}

903
	if ((err = ext4_reserve_inode_write(handle, inode, &iloc)))
904 905 906 907 908 909
		goto exit_bh;

	/*
	 * Finally we can add each of the reserved backup GDT blocks from
	 * the new group to its reserved primary GDT block.
	 */
910
	blk = group * EXT4_BLOCKS_PER_GROUP(sb);
911 912 913 914 915 916 917
	for (i = 0; i < reserved_gdb; i++) {
		int err2;
		data = (__le32 *)primary[i]->b_data;
		/* printk("reserving backup %lu[%u] = %lu\n",
		       primary[i]->b_blocknr, gdbackups,
		       blk + primary[i]->b_blocknr); */
		data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr);
918
		err2 = ext4_handle_dirty_metadata(handle, NULL, primary[i]);
919 920 921 922
		if (!err)
			err = err2;
	}
	inode->i_blocks += reserved_gdb * sb->s_blocksize >> 9;
923
	ext4_mark_iloc_dirty(handle, inode, &iloc);
924 925 926 927 928 929 930 931 932 933 934 935 936

exit_bh:
	while (--res >= 0)
		brelse(primary[res]);
	brelse(dind);

exit_free:
	kfree(primary);

	return err;
}

/*
937
 * Update the backup copies of the ext4 metadata.  These don't need to be part
938 939 940 941 942 943 944
 * of the main resize transaction, because e2fsck will re-write them if there
 * is a problem (basically only OOM will cause a problem).  However, we
 * _should_ update the backups if possible, in case the primary gets trashed
 * for some reason and we need to run e2fsck from a backup superblock.  The
 * important part is that the new block and inode counts are in the backup
 * superblocks, and the location of the new group metadata in the GDT backups.
 *
945 946 947 948 949 950
 * We do not need take the s_resize_lock for this, because these
 * blocks are not otherwise touched by the filesystem code when it is
 * mounted.  We don't need to worry about last changing from
 * sbi->s_groups_count, because the worst that can happen is that we
 * do not copy the full number of backups at this time.  The resize
 * which changed s_groups_count will backup again.
951 952 953 954
 */
static void update_backups(struct super_block *sb,
			   int blk_off, char *data, int size)
{
955
	struct ext4_sb_info *sbi = EXT4_SB(sb);
956
	const ext4_group_t last = sbi->s_groups_count;
957
	const int bpg = EXT4_BLOCKS_PER_GROUP(sb);
958 959 960
	unsigned three = 1;
	unsigned five = 5;
	unsigned seven = 7;
961
	ext4_group_t group;
962 963 964 965
	int rest = sb->s_blocksize - size;
	handle_t *handle;
	int err = 0, err2;

966
	handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA);
967 968 969 970 971 972
	if (IS_ERR(handle)) {
		group = 1;
		err = PTR_ERR(handle);
		goto exit_err;
	}

973 974
	ext4_superblock_csum_set(sb, (struct ext4_super_block *)data);

975
	while ((group = ext4_list_backups(sb, &three, &five, &seven)) < last) {
976 977 978
		struct buffer_head *bh;

		/* Out of journal space, and can't get more - abort - so sad */
979 980
		if (ext4_handle_valid(handle) &&
		    handle->h_buffer_credits == 0 &&
981 982
		    ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA) &&
		    (err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA)))
983 984 985 986 987 988 989
			break;

		bh = sb_getblk(sb, group * bpg + blk_off);
		if (!bh) {
			err = -EIO;
			break;
		}
990
		ext4_debug("update metadata backup %#04lx\n",
991
			  (unsigned long)bh->b_blocknr);
992
		if ((err = ext4_journal_get_write_access(handle, bh)))
993 994 995 996 997 998 999
			break;
		lock_buffer(bh);
		memcpy(bh->b_data, data, size);
		if (rest)
			memset(bh->b_data + size, 0, rest);
		set_buffer_uptodate(bh);
		unlock_buffer(bh);
1000 1001 1002
		err = ext4_handle_dirty_metadata(handle, NULL, bh);
		if (unlikely(err))
			ext4_std_error(sb, err);
1003 1004
		brelse(bh);
	}
1005
	if ((err2 = ext4_journal_stop(handle)) && !err)
1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019
		err = err2;

	/*
	 * Ugh! Need to have e2fsck write the backup copies.  It is too
	 * late to revert the resize, we shouldn't fail just because of
	 * the backup copies (they are only needed in case of corruption).
	 *
	 * However, if we got here we have a journal problem too, so we
	 * can't really start a transaction to mark the superblock.
	 * Chicken out and just set the flag on the hope it will be written
	 * to disk, and if not - we will simply wait until next fsck.
	 */
exit_err:
	if (err) {
1020
		ext4_warning(sb, "can't update backup for group %u (err %d), "
1021
			     "forcing fsck on next reboot", group, err);
1022 1023
		sbi->s_mount_state &= ~EXT4_VALID_FS;
		sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1024 1025 1026 1027
		mark_buffer_dirty(sbi->s_sbh);
	}
}

1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073
/*
 * ext4_add_new_descs() adds @count group descriptor of groups
 * starting at @group
 *
 * @handle: journal handle
 * @sb: super block
 * @group: the group no. of the first group desc to be added
 * @resize_inode: the resize inode
 * @count: number of group descriptors to be added
 */
static int ext4_add_new_descs(handle_t *handle, struct super_block *sb,
			      ext4_group_t group, struct inode *resize_inode,
			      ext4_group_t count)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_super_block *es = sbi->s_es;
	struct buffer_head *gdb_bh;
	int i, gdb_off, gdb_num, err = 0;

	for (i = 0; i < count; i++, group++) {
		int reserved_gdb = ext4_bg_has_super(sb, group) ?
			le16_to_cpu(es->s_reserved_gdt_blocks) : 0;

		gdb_off = group % EXT4_DESC_PER_BLOCK(sb);
		gdb_num = group / EXT4_DESC_PER_BLOCK(sb);

		/*
		 * We will only either add reserved group blocks to a backup group
		 * or remove reserved blocks for the first group in a new group block.
		 * Doing both would be mean more complex code, and sane people don't
		 * use non-sparse filesystems anymore.  This is already checked above.
		 */
		if (gdb_off) {
			gdb_bh = sbi->s_group_desc[gdb_num];
			err = ext4_journal_get_write_access(handle, gdb_bh);

			if (!err && reserved_gdb && ext4_bg_num_gdb(sb, group))
				err = reserve_backup_gdb(handle, resize_inode, group);
		} else
			err = add_new_gdb(handle, resize_inode, group);
		if (err)
			break;
	}
	return err;
}

1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111
static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block)
{
	struct buffer_head *bh = sb_getblk(sb, block);
	if (!bh)
		return NULL;

	if (bitmap_uptodate(bh))
		return bh;

	lock_buffer(bh);
	if (bh_submit_read(bh) < 0) {
		unlock_buffer(bh);
		brelse(bh);
		return NULL;
	}
	unlock_buffer(bh);

	return bh;
}

static int ext4_set_bitmap_checksums(struct super_block *sb,
				     ext4_group_t group,
				     struct ext4_group_desc *gdp,
				     struct ext4_new_group_data *group_data)
{
	struct buffer_head *bh;

	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
		return 0;

	bh = ext4_get_bitmap(sb, group_data->inode_bitmap);
	if (!bh)
		return -EIO;
	ext4_inode_bitmap_csum_set(sb, group, gdp, bh,
				   EXT4_INODES_PER_GROUP(sb) / 8);
	brelse(bh);

1112 1113 1114 1115 1116 1117 1118
	bh = ext4_get_bitmap(sb, group_data->block_bitmap);
	if (!bh)
		return -EIO;
	ext4_block_bitmap_csum_set(sb, group, gdp, bh,
				   EXT4_BLOCKS_PER_GROUP(sb) / 8);
	brelse(bh);

1119 1120 1121
	return 0;
}

1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147
/*
 * ext4_setup_new_descs() will set up the group descriptor descriptors of a flex bg
 */
static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb,
				struct ext4_new_flex_group_data *flex_gd)
{
	struct ext4_new_group_data	*group_data = flex_gd->groups;
	struct ext4_group_desc		*gdp;
	struct ext4_sb_info		*sbi = EXT4_SB(sb);
	struct buffer_head		*gdb_bh;
	ext4_group_t			group;
	__u16				*bg_flags = flex_gd->bg_flags;
	int				i, gdb_off, gdb_num, err = 0;
	

	for (i = 0; i < flex_gd->count; i++, group_data++, bg_flags++) {
		group = group_data->group;

		gdb_off = group % EXT4_DESC_PER_BLOCK(sb);
		gdb_num = group / EXT4_DESC_PER_BLOCK(sb);

		/*
		 * get_write_access() has been called on gdb_bh by ext4_add_new_desc().
		 */
		gdb_bh = sbi->s_group_desc[gdb_num];
		/* Update group descriptor block for new group */
1148
		gdp = (struct ext4_group_desc *)(gdb_bh->b_data +
1149 1150 1151 1152 1153
						 gdb_off * EXT4_DESC_SIZE(sb));

		memset(gdp, 0, EXT4_DESC_SIZE(sb));
		ext4_block_bitmap_set(sb, gdp, group_data->block_bitmap);
		ext4_inode_bitmap_set(sb, gdp, group_data->inode_bitmap);
1154 1155 1156 1157 1158 1159
		err = ext4_set_bitmap_checksums(sb, group, gdp, group_data);
		if (err) {
			ext4_std_error(sb, err);
			break;
		}

1160 1161 1162 1163 1164
		ext4_inode_table_set(sb, gdp, group_data->inode_table);
		ext4_free_group_clusters_set(sb, gdp,
					     EXT4_B2C(sbi, group_data->free_blocks_count));
		ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
		gdp->bg_flags = cpu_to_le16(*bg_flags);
1165
		ext4_group_desc_csum_set(sb, group, gdp);
1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183

		err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
		if (unlikely(err)) {
			ext4_std_error(sb, err);
			break;
		}

		/*
		 * We can allocate memory for mb_alloc based on the new group
		 * descriptor
		 */
		err = ext4_mb_add_groupinfo(sb, group, gdp);
		if (err)
			break;
	}
	return err;
}

1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223
/*
 * ext4_update_super() updates the super block so that the newly added
 * groups can be seen by the filesystem.
 *
 * @sb: super block
 * @flex_gd: new added groups
 */
static void ext4_update_super(struct super_block *sb,
			     struct ext4_new_flex_group_data *flex_gd)
{
	ext4_fsblk_t blocks_count = 0;
	ext4_fsblk_t free_blocks = 0;
	ext4_fsblk_t reserved_blocks = 0;
	struct ext4_new_group_data *group_data = flex_gd->groups;
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_super_block *es = sbi->s_es;
	int i;

	BUG_ON(flex_gd->count == 0 || group_data == NULL);
	/*
	 * Make the new blocks and inodes valid next.  We do this before
	 * increasing the group count so that once the group is enabled,
	 * all of its blocks and inodes are already valid.
	 *
	 * We always allocate group-by-group, then block-by-block or
	 * inode-by-inode within a group, so enabling these
	 * blocks/inodes before the group is live won't actually let us
	 * allocate the new space yet.
	 */
	for (i = 0; i < flex_gd->count; i++) {
		blocks_count += group_data[i].blocks_count;
		free_blocks += group_data[i].free_blocks_count;
	}

	reserved_blocks = ext4_r_blocks_count(es) * 100;
	do_div(reserved_blocks, ext4_blocks_count(es));
	reserved_blocks *= blocks_count;
	do_div(reserved_blocks, 100);

	ext4_blocks_count_set(es, ext4_blocks_count(es) + blocks_count);
1224
	ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + free_blocks);
1225 1226
	le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) *
		     flex_gd->count);
1227 1228
	le32_add_cpu(&es->s_free_inodes_count, EXT4_INODES_PER_GROUP(sb) *
		     flex_gd->count);
1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280

	/*
	 * We need to protect s_groups_count against other CPUs seeing
	 * inconsistent state in the superblock.
	 *
	 * The precise rules we use are:
	 *
	 * * Writers must perform a smp_wmb() after updating all
	 *   dependent data and before modifying the groups count
	 *
	 * * Readers must perform an smp_rmb() after reading the groups
	 *   count and before reading any dependent data.
	 *
	 * NB. These rules can be relaxed when checking the group count
	 * while freeing data, as we can only allocate from a block
	 * group after serialising against the group count, and we can
	 * only then free after serialising in turn against that
	 * allocation.
	 */
	smp_wmb();

	/* Update the global fs size fields */
	sbi->s_groups_count += flex_gd->count;

	/* Update the reserved block counts only once the new group is
	 * active. */
	ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) +
				reserved_blocks);

	/* Update the free space counts */
	percpu_counter_add(&sbi->s_freeclusters_counter,
			   EXT4_B2C(sbi, free_blocks));
	percpu_counter_add(&sbi->s_freeinodes_counter,
			   EXT4_INODES_PER_GROUP(sb) * flex_gd->count);

	if (EXT4_HAS_INCOMPAT_FEATURE(sb,
				      EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
	    sbi->s_log_groups_per_flex) {
		ext4_group_t flex_group;
		flex_group = ext4_flex_group(sbi, group_data[0].group);
		atomic_add(EXT4_B2C(sbi, free_blocks),
			   &sbi->s_flex_groups[flex_group].free_clusters);
		atomic_add(EXT4_INODES_PER_GROUP(sb) * flex_gd->count,
			   &sbi->s_flex_groups[flex_group].free_inodes);
	}

	if (test_opt(sb, DEBUG))
		printk(KERN_DEBUG "EXT4-fs: added group %u:"
		       "%llu blocks(%llu free %llu reserved)\n", flex_gd->count,
		       blocks_count, free_blocks, reserved_blocks);
}

1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362
/* Add a flex group to an fs. Ensure we handle all possible error conditions
 * _before_ we start modifying the filesystem, because we cannot abort the
 * transaction and not have it write the data to disk.
 */
static int ext4_flex_group_add(struct super_block *sb,
			       struct inode *resize_inode,
			       struct ext4_new_flex_group_data *flex_gd)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_super_block *es = sbi->s_es;
	ext4_fsblk_t o_blocks_count;
	ext4_grpblk_t last;
	ext4_group_t group;
	handle_t *handle;
	unsigned reserved_gdb;
	int err = 0, err2 = 0, credit;

	BUG_ON(!flex_gd->count || !flex_gd->groups || !flex_gd->bg_flags);

	reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks);
	o_blocks_count = ext4_blocks_count(es);
	ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
	BUG_ON(last);

	err = setup_new_flex_group_blocks(sb, flex_gd);
	if (err)
		goto exit;
	/*
	 * We will always be modifying at least the superblock and  GDT
	 * block.  If we are adding a group past the last current GDT block,
	 * we will also modify the inode and the dindirect block.  If we
	 * are adding a group with superblock/GDT backups  we will also
	 * modify each of the reserved GDT dindirect blocks.
	 */
	credit = flex_gd->count * 4 + reserved_gdb;
	handle = ext4_journal_start_sb(sb, credit);
	if (IS_ERR(handle)) {
		err = PTR_ERR(handle);
		goto exit;
	}

	err = ext4_journal_get_write_access(handle, sbi->s_sbh);
	if (err)
		goto exit_journal;

	group = flex_gd->groups[0].group;
	BUG_ON(group != EXT4_SB(sb)->s_groups_count);
	err = ext4_add_new_descs(handle, sb, group,
				resize_inode, flex_gd->count);
	if (err)
		goto exit_journal;

	err = ext4_setup_new_descs(handle, sb, flex_gd);
	if (err)
		goto exit_journal;

	ext4_update_super(sb, flex_gd);

	err = ext4_handle_dirty_super(handle, sb);

exit_journal:
	err2 = ext4_journal_stop(handle);
	if (!err)
		err = err2;

	if (!err) {
		int i;
		update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
			       sizeof(struct ext4_super_block));
		for (i = 0; i < flex_gd->count; i++, group++) {
			struct buffer_head *gdb_bh;
			int gdb_num;
			gdb_num = group / EXT4_BLOCKS_PER_GROUP(sb);
			gdb_bh = sbi->s_group_desc[gdb_num];
			update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data,
				       gdb_bh->b_size);
		}
	}
exit:
	return err;
}

1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403
static int ext4_setup_next_flex_gd(struct super_block *sb,
				    struct ext4_new_flex_group_data *flex_gd,
				    ext4_fsblk_t n_blocks_count,
				    unsigned long flexbg_size)
{
	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
	struct ext4_new_group_data *group_data = flex_gd->groups;
	ext4_fsblk_t o_blocks_count;
	ext4_group_t n_group;
	ext4_group_t group;
	ext4_group_t last_group;
	ext4_grpblk_t last;
	ext4_grpblk_t blocks_per_group;
	unsigned long i;

	blocks_per_group = EXT4_BLOCKS_PER_GROUP(sb);

	o_blocks_count = ext4_blocks_count(es);

	if (o_blocks_count == n_blocks_count)
		return 0;

	ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
	BUG_ON(last);
	ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &last);

	last_group = group | (flexbg_size - 1);
	if (last_group > n_group)
		last_group = n_group;

	flex_gd->count = last_group - group + 1;

	for (i = 0; i < flex_gd->count; i++) {
		int overhead;

		group_data[i].group = group + i;
		group_data[i].blocks_count = blocks_per_group;
		overhead = ext4_bg_has_super(sb, group + i) ?
			   (1 + ext4_bg_num_gdb(sb, group + i) +
			    le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
		group_data[i].free_blocks_count = blocks_per_group - overhead;
1404
		if (ext4_has_group_desc_csum(sb))
1405 1406 1407 1408 1409 1410
			flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT |
					       EXT4_BG_INODE_UNINIT;
		else
			flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED;
	}

1411
	if (last_group == n_group && ext4_has_group_desc_csum(sb))
1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423
		/* We need to initialize block bitmap of last group. */
		flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT;

	if ((last_group == n_group) && (last != blocks_per_group - 1)) {
		group_data[i - 1].blocks_count = last + 1;
		group_data[i - 1].free_blocks_count -= blocks_per_group-
					last - 1;
	}

	return 1;
}

1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436
/* Add group descriptor data to an existing or new group descriptor block.
 * Ensure we handle all possible error conditions _before_ we start modifying
 * the filesystem, because we cannot abort the transaction and not have it
 * write the data to disk.
 *
 * If we are on a GDT block boundary, we need to get the reserved GDT block.
 * Otherwise, we may need to add backup GDT blocks for a sparse group.
 *
 * We only need to hold the superblock lock while we are actually adding
 * in the new group's counts to the superblock.  Prior to that we have
 * not really "added" the group at all.  We re-check that we are still
 * adding in the last group in case things have changed since verifying.
 */
1437
int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
1438
{
1439
	struct ext4_new_flex_group_data flex_gd;
1440 1441 1442
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_super_block *es = sbi->s_es;
	int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
1443 1444 1445
		le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
	struct inode *inode = NULL;
	int gdb_off, gdb_num;
1446 1447
	int err;
	__u16 bg_flags = 0;
1448

1449 1450
	gdb_num = input->group / EXT4_DESC_PER_BLOCK(sb);
	gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb);
1451

1452 1453
	if (gdb_off == 0 && !EXT4_HAS_RO_COMPAT_FEATURE(sb,
					EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
1454
		ext4_warning(sb, "Can't resize non-sparse filesystem further");
1455 1456 1457
		return -EPERM;
	}

L
Laurent Vivier 已提交
1458 1459
	if (ext4_blocks_count(es) + input->blocks_count <
	    ext4_blocks_count(es)) {
1460
		ext4_warning(sb, "blocks_count overflow");
1461 1462 1463
		return -EINVAL;
	}

1464
	if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) <
1465
	    le32_to_cpu(es->s_inodes_count)) {
1466
		ext4_warning(sb, "inodes_count overflow");
1467 1468 1469 1470
		return -EINVAL;
	}

	if (reserved_gdb || gdb_off == 0) {
1471
		if (!EXT4_HAS_COMPAT_FEATURE(sb,
1472 1473
					     EXT4_FEATURE_COMPAT_RESIZE_INODE)
		    || !le16_to_cpu(es->s_reserved_gdt_blocks)) {
1474
			ext4_warning(sb,
1475 1476 1477
				     "No reserved GDT blocks, can't resize");
			return -EPERM;
		}
1478 1479
		inode = ext4_iget(sb, EXT4_RESIZE_INO);
		if (IS_ERR(inode)) {
1480
			ext4_warning(sb, "Error opening resize inode");
1481
			return PTR_ERR(inode);
1482 1483 1484
		}
	}

1485

1486
	err = verify_group_input(sb, input);
1487
	if (err)
1488
		goto out;
1489

1490 1491 1492 1493 1494
	flex_gd.count = 1;
	flex_gd.groups = input;
	flex_gd.bg_flags = &bg_flags;
	err = ext4_flex_group_add(sb, inode, &flex_gd);
out:
1495 1496
	iput(inode);
	return err;
1497
} /* ext4_group_add */
1498

1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525
/*
 * extend a group without checking assuming that checking has been done.
 */
static int ext4_group_extend_no_check(struct super_block *sb,
				      ext4_fsblk_t o_blocks_count, ext4_grpblk_t add)
{
	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
	handle_t *handle;
	int err = 0, err2;

	/* We will update the superblock, one block bitmap, and
	 * one group descriptor via ext4_group_add_blocks().
	 */
	handle = ext4_journal_start_sb(sb, 3);
	if (IS_ERR(handle)) {
		err = PTR_ERR(handle);
		ext4_warning(sb, "error %d on journal start", err);
		return err;
	}

	err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
	if (err) {
		ext4_warning(sb, "error %d on journal write access", err);
		goto errout;
	}

	ext4_blocks_count_set(es, o_blocks_count + add);
1526
	ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + add);
1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550
	ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count,
		   o_blocks_count + add);
	/* We add the blocks to the bitmap and set the group need init bit */
	err = ext4_group_add_blocks(handle, sb, o_blocks_count, add);
	if (err)
		goto errout;
	ext4_handle_dirty_super(handle, sb);
	ext4_debug("freed blocks %llu through %llu\n", o_blocks_count,
		   o_blocks_count + add);
errout:
	err2 = ext4_journal_stop(handle);
	if (err2 && !err)
		err = err2;

	if (!err) {
		if (test_opt(sb, DEBUG))
			printk(KERN_DEBUG "EXT4-fs: extended group to %llu "
			       "blocks\n", ext4_blocks_count(es));
		update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr, (char *)es,
			       sizeof(struct ext4_super_block));
	}
	return err;
}

1551 1552
/*
 * Extend the filesystem to the new number of blocks specified.  This entry
1553 1554 1555 1556
 * point is only used to extend the current filesystem to the end of the last
 * existing group.  It can be accessed via ioctl, or by "remount,resize=<size>"
 * for emergencies (because it has no dependencies on reserved blocks).
 *
1557
 * If we _really_ wanted, we could use default values to call ext4_group_add()
1558 1559 1560
 * allow the "remount" trick to work for arbitrary resizing, assuming enough
 * GDT blocks are reserved to grow to the desired size.
 */
1561 1562
int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
		      ext4_fsblk_t n_blocks_count)
1563
{
1564 1565 1566
	ext4_fsblk_t o_blocks_count;
	ext4_grpblk_t last;
	ext4_grpblk_t add;
1567
	struct buffer_head *bh;
1568
	int err;
1569
	ext4_group_t group;
1570

L
Laurent Vivier 已提交
1571
	o_blocks_count = ext4_blocks_count(es);
1572 1573

	if (test_opt(sb, DEBUG))
1574 1575 1576
		ext4_msg(sb, KERN_DEBUG,
			 "extending last group from %llu to %llu blocks",
			 o_blocks_count, n_blocks_count);
1577 1578 1579 1580 1581

	if (n_blocks_count == 0 || n_blocks_count == o_blocks_count)
		return 0;

	if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1582 1583 1584
		ext4_msg(sb, KERN_ERR,
			 "filesystem too large to resize to %llu blocks safely",
			 n_blocks_count);
1585
		if (sizeof(sector_t) < 8)
1586
			ext4_warning(sb, "CONFIG_LBDAF not enabled");
1587 1588 1589 1590
		return -EINVAL;
	}

	if (n_blocks_count < o_blocks_count) {
1591
		ext4_warning(sb, "can't shrink FS - resize aborted");
1592
		return -EINVAL;
1593 1594 1595
	}

	/* Handle the remaining blocks in the last group only. */
1596
	ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1597 1598

	if (last == 0) {
1599
		ext4_warning(sb, "need to use ext2online to resize further");
1600 1601 1602
		return -EPERM;
	}

1603
	add = EXT4_BLOCKS_PER_GROUP(sb) - last;
1604 1605

	if (o_blocks_count + add < o_blocks_count) {
1606
		ext4_warning(sb, "blocks_count overflow");
1607 1608 1609 1610 1611 1612 1613
		return -EINVAL;
	}

	if (o_blocks_count + add > n_blocks_count)
		add = n_blocks_count - o_blocks_count;

	if (o_blocks_count + add < n_blocks_count)
1614
		ext4_warning(sb, "will only finish group (%llu blocks, %u new)",
1615 1616 1617
			     o_blocks_count + add, add);

	/* See if the device is actually as big as what was requested */
1618
	bh = sb_bread(sb, o_blocks_count + add - 1);
1619
	if (!bh) {
1620
		ext4_warning(sb, "can't read last block, resize aborted");
1621 1622 1623 1624
		return -ENOSPC;
	}
	brelse(bh);

1625
	err = ext4_group_extend_no_check(sb, o_blocks_count, add);
1626
	return err;
1627
} /* ext4_group_extend */
1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644

/*
 * ext4_resize_fs() resizes a fs to new size specified by @n_blocks_count
 *
 * @sb: super block of the fs to be resized
 * @n_blocks_count: the number of blocks resides in the resized fs
 */
int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
{
	struct ext4_new_flex_group_data *flex_gd = NULL;
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_super_block *es = sbi->s_es;
	struct buffer_head *bh;
	struct inode *resize_inode;
	ext4_fsblk_t o_blocks_count;
	ext4_group_t o_group;
	ext4_group_t n_group;
1645
	ext4_grpblk_t offset, add;
1646 1647 1648 1649 1650 1651 1652 1653
	unsigned long n_desc_blocks;
	unsigned long o_desc_blocks;
	unsigned long desc_blocks;
	int err = 0, flexbg_size = 1;

	o_blocks_count = ext4_blocks_count(es);

	if (test_opt(sb, DEBUG))
1654 1655
		ext4_msg(sb, KERN_DEBUG, "resizing filesystem from %llu "
		       "to %llu blocks", o_blocks_count, n_blocks_count);
1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667

	if (n_blocks_count < o_blocks_count) {
		/* On-line shrinking not supported */
		ext4_warning(sb, "can't shrink FS - resize aborted");
		return -EINVAL;
	}

	if (n_blocks_count == o_blocks_count)
		/* Nothing need to do */
		return 0;

	ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &offset);
1668
	ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset);
1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696

	n_desc_blocks = (n_group + EXT4_DESC_PER_BLOCK(sb)) /
			EXT4_DESC_PER_BLOCK(sb);
	o_desc_blocks = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
			EXT4_DESC_PER_BLOCK(sb);
	desc_blocks = n_desc_blocks - o_desc_blocks;

	if (desc_blocks &&
	    (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_RESIZE_INODE) ||
	     le16_to_cpu(es->s_reserved_gdt_blocks) < desc_blocks)) {
		ext4_warning(sb, "No reserved GDT blocks, can't resize");
		return -EPERM;
	}

	resize_inode = ext4_iget(sb, EXT4_RESIZE_INO);
	if (IS_ERR(resize_inode)) {
		ext4_warning(sb, "Error opening resize inode");
		return PTR_ERR(resize_inode);
	}

	/* See if the device is actually as big as what was requested */
	bh = sb_bread(sb, n_blocks_count - 1);
	if (!bh) {
		ext4_warning(sb, "can't read last block, resize aborted");
		return -ENOSPC;
	}
	brelse(bh);

1697 1698 1699 1700 1701 1702
	/* extend the last group */
	if (n_group == o_group)
		add = n_blocks_count - o_blocks_count;
	else
		add = EXT4_BLOCKS_PER_GROUP(sb) - (offset + 1);
	if (add > 0) {
1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738
		err = ext4_group_extend_no_check(sb, o_blocks_count, add);
		if (err)
			goto out;
	}

	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
	    es->s_log_groups_per_flex)
		flexbg_size = 1 << es->s_log_groups_per_flex;

	o_blocks_count = ext4_blocks_count(es);
	if (o_blocks_count == n_blocks_count)
		goto out;

	flex_gd = alloc_flex_gd(flexbg_size);
	if (flex_gd == NULL) {
		err = -ENOMEM;
		goto out;
	}

	/* Add flex groups. Note that a regular group is a
	 * flex group with 1 group.
	 */
	while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count,
					      flexbg_size)) {
		ext4_alloc_group_tables(sb, flex_gd, flexbg_size);
		err = ext4_flex_group_add(sb, resize_inode, flex_gd);
		if (unlikely(err))
			break;
	}

out:
	if (flex_gd)
		free_flex_gd(flex_gd);

	iput(resize_inode);
	if (test_opt(sb, DEBUG))
1739 1740
		ext4_msg(sb, KERN_DEBUG, "resized filesystem from %llu "
		       "upto %llu blocks", o_blocks_count, n_blocks_count);
1741 1742
	return err;
}