Esempio n. 1
0
static int find_group_other(struct super_block *sb, struct inode *parent)
{
	int parent_group = EXT4_I(parent)->i_block_group;
	int ngroups = EXT4_SB(sb)->s_groups_count;
	struct ext4_group_desc *desc;
	struct buffer_head *bh;
	int group, i;

	/*
	 * Try to place the inode in its parent directory
	 */
	group = parent_group;
	desc = ext4_get_group_desc (sb, group, &bh);
	if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
			le16_to_cpu(desc->bg_free_blocks_count))
		return group;

	/*
	 * We're going to place this inode in a different blockgroup from its
	 * parent.  We want to cause files in a common directory to all land in
	 * the same blockgroup.  But we want files which are in a different
	 * directory which shares a blockgroup with our parent to land in a
	 * different blockgroup.
	 *
	 * So add our directory's i_ino into the starting point for the hash.
	 */
	group = (group + parent->i_ino) % ngroups;

	/*
	 * Use a quadratic hash to find a group with a free inode and some free
	 * blocks.
	 */
	for (i = 1; i < ngroups; i <<= 1) {
		group += i;
		if (group >= ngroups)
			group -= ngroups;
		desc = ext4_get_group_desc (sb, group, &bh);
		if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
				le16_to_cpu(desc->bg_free_blocks_count))
			return group;
	}

	/*
	 * That failed: try linear search for a free inode, even if that group
	 * has no free blocks.
	 */
	group = parent_group;
	for (i = 0; i < ngroups; i++) {
		if (++group >= ngroups)
			group = 0;
		desc = ext4_get_group_desc (sb, group, &bh);
		if (desc && le16_to_cpu(desc->bg_free_inodes_count))
			return group;
	}

	return -1;
}
Esempio n. 2
0
/**
 * ext4_count_free_blocks() -- count filesystem free blocks
 * @sb:		superblock
 *
 * Adds up the number of free blocks from each block group.
 */
ext4_fsblk_t ext4_count_free_blocks(struct super_block *sb)
{
	ext4_fsblk_t desc_count;
	struct ext4_group_desc *gdp;
	ext4_group_t i;
	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
#ifdef EXT4FS_DEBUG
	struct ext4_super_block *es;
	ext4_fsblk_t bitmap_count;
	unsigned long x;
	struct buffer_head *bitmap_bh = NULL;

	es = EXT4_SB(sb)->s_es;
	desc_count = 0;
	bitmap_count = 0;
	gdp = NULL;

	smp_rmb();
	for (i = 0; i < ngroups; i++) {
		gdp = ext4_get_group_desc(sb, i, NULL);
		if (!gdp)
			continue;
		desc_count += le16_to_cpu(gdp->bg_free_blocks_count);
		brelse(bitmap_bh);
		bitmap_bh = ext4_read_block_bitmap(sb, i);
		if (bitmap_bh == NULL)
			continue;

		x = ext4_count_free(bitmap_bh, sb->s_blocksize);
		printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
			i, le16_to_cpu(gdp->bg_free_blocks_count), x);
		bitmap_count += x;
	}
	brelse(bitmap_bh);
	printk(KERN_DEBUG "ext4_count_free_blocks: stored = %llu"
		", computed = %llu, %llu\n", ext4_free_blocks_count(es),
	       desc_count, bitmap_count);
	return bitmap_count;
#else
	desc_count = 0;
	smp_rmb();
	for (i = 0; i < ngroups; i++) {
		gdp = ext4_get_group_desc(sb, i, NULL);
		if (!gdp)
			continue;
		desc_count += le16_to_cpu(gdp->bg_free_blocks_count);
	}

	return desc_count;
#endif
}
Esempio n. 3
0
/**
 * ext4_count_free_blocks() -- count filesystem free blocks
 * @sb:		superblock
 *
 * Adds up the number of free blocks from each block group.
 */
ext4_fsblk_t ext4_count_free_blocks(struct super_block *sb)
{
	ext4_fsblk_t desc_count;
	struct ext4_group_desc *gdp;
	ext4_group_t i;
	ext4_group_t ngroups = ext4_get_groups_count(sb);
#ifdef EXT4FS_DEBUG
	struct ext4_super_block *es;
	ext4_fsblk_t bitmap_count;
	unsigned int x;
	struct buffer_head *bitmap_bh = NULL;

	es = EXT4_SB(sb)->s_es;
	desc_count = 0;
	bitmap_count = 0;
	gdp = NULL;

	for (i = 0; i < ngroups; i++) {
		gdp = ext4_get_group_desc(sb, i, NULL);
		if (!gdp)
			continue;
		desc_count += ext4_free_blks_count(sb, gdp);
		brelse(bitmap_bh);
		bitmap_bh = ext4_read_block_bitmap(sb, i);
		if (bitmap_bh == NULL)
			continue;

		x = ext4_count_free(bitmap_bh->b_data,
				    EXT4_BLOCKS_PER_GROUP(sb) / 8);
		printk(KERN_DEBUG "group %u: stored = %d, counted = %u\n",
			i, ext4_free_blks_count(sb, gdp), x);
		bitmap_count += x;
	}
	brelse(bitmap_bh);
	printk(KERN_DEBUG "ext4_count_free_blocks: stored = %llu"
		", computed = %llu, %llu\n", ext4_free_blocks_count(es),
	       desc_count, bitmap_count);
	return bitmap_count;
#else
	desc_count = 0;
	for (i = 0; i < ngroups; i++) {
		gdp = ext4_get_group_desc(sb, i, NULL);
		if (!gdp)
			continue;
		desc_count += ext4_free_blks_count(sb, gdp);
	}

	return desc_count;
#endif
}
Esempio n. 4
0
static int ext4_group_used_meta_blocks(struct super_block *sb,
				ext4_group_t block_group)
{
	ext4_fsblk_t tmp;
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	/* block bitmap, inode bitmap, and inode table blocks */
	int used_blocks = sbi->s_itb_per_group + 2;

	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) {
		struct ext4_group_desc *gdp;
		struct buffer_head *bh;

		gdp = ext4_get_group_desc(sb, block_group, &bh);
		if (!ext4_block_in_group(sb, ext4_block_bitmap(sb, gdp),
					block_group))
			used_blocks--;

		if (!ext4_block_in_group(sb, ext4_inode_bitmap(sb, gdp),
					block_group))
			used_blocks--;

		tmp = ext4_inode_table(sb, gdp);
		for (; tmp < ext4_inode_table(sb, gdp) +
				sbi->s_itb_per_group; tmp++) {
			if (!ext4_block_in_group(sb, tmp, block_group))
				used_blocks -= 1;
		}
	}
	return used_blocks;
}
Esempio n. 5
0
/*
 * There are two policies for allocating an inode.  If the new inode is
 * a directory, then a forward search is made for a block group with both
 * free space and a low directory-to-inode ratio; if that fails, then of
 * the groups with above-average free space, that group with the fewest
 * directories already is chosen.
 *
 * For other inodes, search forward from the parent directory\'s block
 * group to find a free inode.
 */
static int find_group_dir(struct super_block *sb, struct inode *parent)
{
	int ngroups = EXT4_SB(sb)->s_groups_count;
	unsigned int freei, avefreei;
	struct ext4_group_desc *desc, *best_desc = NULL;
	struct buffer_head *bh;
	int group, best_group = -1;

	freei = percpu_counter_read_positive(&EXT4_SB(sb)->s_freeinodes_counter);
	avefreei = freei / ngroups;

	for (group = 0; group < ngroups; group++) {
		desc = ext4_get_group_desc (sb, group, &bh);
		if (!desc || !desc->bg_free_inodes_count)
			continue;
		if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
			continue;
		if (!best_desc ||
		    (le16_to_cpu(desc->bg_free_blocks_count) >
		     le16_to_cpu(best_desc->bg_free_blocks_count))) {
			best_group = group;
			best_desc = desc;
		}
	}
	return best_group;
}
Esempio n. 6
0
unsigned long ext4_count_free_inodes (struct super_block * sb)
{
	unsigned long desc_count;
	struct ext4_group_desc *gdp;
	int i;
#ifdef EXT4FS_DEBUG
	struct ext4_super_block *es;
	unsigned long bitmap_count, x;
	struct buffer_head *bitmap_bh = NULL;

	es = EXT4_SB(sb)->s_es;
	desc_count = 0;
	bitmap_count = 0;
	gdp = NULL;
	for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
		gdp = ext4_get_group_desc (sb, i, NULL);
		if (!gdp)
			continue;
		desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
		brelse(bitmap_bh);
		bitmap_bh = read_inode_bitmap(sb, i);
		if (!bitmap_bh)
			continue;

		x = ext4_count_free(bitmap_bh, EXT4_INODES_PER_GROUP(sb) / 8);
		printk("group %d: stored = %d, counted = %lu\n",
			i, le16_to_cpu(gdp->bg_free_inodes_count), x);
		bitmap_count += x;
	}
	brelse(bitmap_bh);
	printk("ext4_count_free_inodes: stored = %u, computed = %lu, %lu\n",
		le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
	return desc_count;
#else
	desc_count = 0;
	for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
		gdp = ext4_get_group_desc (sb, i, NULL);
		if (!gdp)
			continue;
		desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
		cond_resched();
	}
	return desc_count;
#endif
}
Esempio n. 7
0
/* Called at mount-time, super-block is locked */
unsigned long ext4_count_dirs (struct super_block * sb)
{
	unsigned long count = 0;
	int i;

	for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
		struct ext4_group_desc *gdp = ext4_get_group_desc (sb, i, NULL);
		if (!gdp)
			continue;
		count += le16_to_cpu(gdp->bg_used_dirs_count);
	}
	return count;
}
Esempio n. 8
0
/*
 * Read the inode allocation bitmap for a given block_group, reading
 * into the specified slot in the superblock's bitmap cache.
 *
 * Return buffer_head of bitmap on success or NULL.
 */
static struct buffer_head *
read_inode_bitmap(struct super_block * sb, unsigned long block_group)
{
	struct ext4_group_desc *desc;
	struct buffer_head *bh = NULL;

	desc = ext4_get_group_desc(sb, block_group, NULL);
	if (!desc)
		goto error_out;

	bh = sb_bread(sb, ext4_inode_bitmap(sb, desc));
	if (!bh)
		ext4_error(sb, "read_inode_bitmap",
			    "Cannot read inode bitmap - "
			    "block_group = %lu, inode_bitmap = %llu",
			    block_group, ext4_inode_bitmap(sb, desc));
error_out:
	return bh;
}
int ext4_setup_system_zone(struct super_block *sb)
{
	ext4_group_t ngroups = ext4_get_groups_count(sb);
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_group_desc *gdp;
	ext4_group_t i;
	int flex_size = ext4_flex_bg_size(sbi);
	int ret;

	if (!test_opt(sb, BLOCK_VALIDITY)) {
		if (EXT4_SB(sb)->system_blks.rb_node)
			ext4_release_system_zone(sb);
		return 0;
	}
	if (EXT4_SB(sb)->system_blks.rb_node)
		return 0;

	for (i=0; i < ngroups; i++) {
		if (ext4_bg_has_super(sb, i) &&
		    ((i < 5) || ((i % flex_size) == 0)))
			add_system_zone(sbi, ext4_group_first_block_no(sb, i),
					ext4_bg_num_gdb(sb, i) + 1);
		gdp = ext4_get_group_desc(sb, i, NULL);
		ret = add_system_zone(sbi, ext4_block_bitmap(sb, gdp), 1);
		if (ret)
			return ret;
		ret = add_system_zone(sbi, ext4_inode_bitmap(sb, gdp), 1);
		if (ret)
			return ret;
		ret = add_system_zone(sbi, ext4_inode_table(sb, gdp),
				sbi->s_itb_per_group);
		if (ret)
			return ret;
	}

	if (test_opt(sb, DEBUG))
		debug_print_tree(EXT4_SB(sb));
	return 0;
}
Esempio n. 10
0
/**
 * ext4_add_groupblocks() -- Add given blocks to an existing group
 * @handle:			handle to this transaction
 * @sb:				super block
 * @block:			start physcial block to add to the block group
 * @count:			number of blocks to free
 *
 * This marks the blocks as free in the bitmap. We ask the
 * mballoc to reload the buddy after this by setting group
 * EXT4_GROUP_INFO_NEED_INIT_BIT flag
 */
void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
			 ext4_fsblk_t block, unsigned long count)
{
	struct buffer_head *bitmap_bh = NULL;
	struct buffer_head *gd_bh;
	ext4_group_t block_group;
	ext4_grpblk_t bit;
	unsigned int i;
	struct ext4_group_desc *desc;
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	int err = 0, ret, blk_free_count;
	ext4_grpblk_t blocks_freed;
	struct ext4_group_info *grp;

	ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1);

	ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
	grp = ext4_get_group_info(sb, block_group);
	/*
	 * Check to see if we are freeing blocks across a group
	 * boundary.
	 */
	if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) {
		goto error_return;
	}
	bitmap_bh = ext4_read_block_bitmap(sb, block_group);
	if (!bitmap_bh)
		goto error_return;
	desc = ext4_get_group_desc(sb, block_group, &gd_bh);
	if (!desc)
		goto error_return;

	if (in_range(ext4_block_bitmap(sb, desc), block, count) ||
	    in_range(ext4_inode_bitmap(sb, desc), block, count) ||
	    in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
	    in_range(block + count - 1, ext4_inode_table(sb, desc),
		     sbi->s_itb_per_group)) {
		ext4_error(sb, __func__,
			   "Adding blocks in system zones - "
			   "Block = %llu, count = %lu",
			   block, count);
		goto error_return;
	}

	/*
	 * We are about to add blocks to the bitmap,
	 * so we need undo access.
	 */
	BUFFER_TRACE(bitmap_bh, "getting undo access");
	err = ext4_journal_get_undo_access(handle, bitmap_bh);
	if (err)
		goto error_return;

	/*
	 * We are about to modify some metadata.  Call the journal APIs
	 * to unshare ->b_data if a currently-committing transaction is
	 * using it
	 */
	BUFFER_TRACE(gd_bh, "get_write_access");
	err = ext4_journal_get_write_access(handle, gd_bh);
	if (err)
		goto error_return;
	/*
	 * make sure we don't allow a parallel init on other groups in the
	 * same buddy cache
	 */
	down_write(&grp->alloc_sem);
	for (i = 0, blocks_freed = 0; i < count; i++) {
		BUFFER_TRACE(bitmap_bh, "clear bit");
		if (!ext4_clear_bit_atomic(ext4_group_lock_ptr(sb, block_group),
						bit + i, bitmap_bh->b_data)) {
			ext4_error(sb, __func__,
				   "bit already cleared for block %llu",
				   (ext4_fsblk_t)(block + i));
			BUFFER_TRACE(bitmap_bh, "bit already cleared");
		} else {
			blocks_freed++;
		}
	}
	ext4_lock_group(sb, block_group);
	blk_free_count = blocks_freed + ext4_free_blks_count(sb, desc);
	ext4_free_blks_set(sb, desc, blk_free_count);
	desc->bg_checksum = ext4_group_desc_csum(sbi, block_group, desc);
	ext4_unlock_group(sb, block_group);
	percpu_counter_mod(&sbi->s_freeblocks_counter, blocks_freed);

	if (sbi->s_log_groups_per_flex) {
		ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
		atomic_add(blocks_freed,
			   &sbi->s_flex_groups[flex_group].free_blocks);
	}
	/*
	 * request to reload the buddy with the
	 * new bitmap information
	 */
	set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
	grp->bb_free += blocks_freed;
	up_write(&grp->alloc_sem);

	/* We dirtied the bitmap block */
	BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
	err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);

	/* And the group descriptor block */
	BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
	ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
	if (!err)
		err = ret;

error_return:
	brelse(bitmap_bh);
	ext4_std_error(sb, err);
	return;
}
Esempio n. 11
0
/**
 * ext4_read_block_bitmap()
 * @sb:			super block
 * @block_group:	given block group
 *
 * Read the bitmap for a given block_group,and validate the
 * bits for block/inode/inode tables are set in the bitmaps
 *
 * Return buffer_head on success or NULL in case of failure.
 */
struct buffer_head *
ext4_read_block_bitmap(struct super_block *sb, ext4_group_t block_group)
{
	struct ext4_group_desc *desc;
	struct buffer_head *bh = NULL;
	ext4_fsblk_t bitmap_blk;

	desc = ext4_get_group_desc(sb, block_group, NULL);
	if (!desc)
		return NULL;
	bitmap_blk = ext4_block_bitmap(sb, desc);
	bh = sb_getblk(sb, bitmap_blk);
	if (unlikely(!bh)) {
		ext4_error(sb, __func__,
			    "Cannot read block bitmap - "
			    "block_group = %u, block_bitmap = %llu",
			    block_group, bitmap_blk);
		return NULL;
	}

	if (bitmap_uptodate(bh))
		return bh;

	lock_buffer(bh);
	if (bitmap_uptodate(bh)) {
		unlock_buffer(bh);
		return bh;
	}
	ext4_lock_group(sb, block_group);
	if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
		ext4_init_block_bitmap(sb, bh, block_group, desc);
		set_bitmap_uptodate(bh);
		set_buffer_uptodate(bh);
		ext4_unlock_group(sb, block_group);
		unlock_buffer(bh);
		return bh;
	}
	ext4_unlock_group(sb, block_group);
	if (buffer_uptodate(bh)) {
		/*
		 * if not uninit if bh is uptodate,
		 * bitmap is also uptodate
		 */
		set_bitmap_uptodate(bh);
		unlock_buffer(bh);
		return bh;
	}
	/*
	 * submit the buffer_head for read. We can
	 * safely mark the bitmap as uptodate now.
	 * We do it here so the bitmap uptodate bit
	 * get set with buffer lock held.
	 */
	set_bitmap_uptodate(bh);
	if (bh_submit_read(bh) < 0) {
		put_bh(bh);
		ext4_error(sb, __func__,
			    "Cannot read block bitmap - "
			    "block_group = %u, block_bitmap = %llu",
			    block_group, bitmap_blk);
		return NULL;
	}
	ext4_valid_block_bitmap(sb, desc, block_group, bh);
	/*
	 * file system mounted not to panic on error,
	 * continue with corrupt bitmap
	 */
	return bh;
}
Esempio n. 12
0
/*
 * NOTE! When we get the inode, we're the only people
 * that have access to it, and as such there are no
 * race conditions we have to worry about. The inode
 * is not on the hash-lists, and it cannot be reached
 * through the filesystem because the directory entry
 * has been deleted earlier.
 *
 * HOWEVER: we must make sure that we get no aliases,
 * which means that we have to call "clear_inode()"
 * _before_ we mark the inode not in use in the inode
 * bitmaps. Otherwise a newly created file might use
 * the same inode number (not actually the same pointer
 * though), and then we'd have two inodes sharing the
 * same inode number and space on the harddisk.
 */
void ext4_free_inode (handle_t *handle, struct inode * inode)
{
	struct super_block * sb = inode->i_sb;
	int is_directory;
	unsigned long ino;
	struct buffer_head *bitmap_bh = NULL;
	struct buffer_head *bh2;
	unsigned long block_group;
	unsigned long bit;
	struct ext4_group_desc * gdp;
	struct ext4_super_block * es;
	struct ext4_sb_info *sbi;
	int fatal = 0, err;

	if (atomic_read(&inode->i_count) > 1) {
		printk ("ext4_free_inode: inode has count=%d\n",
					atomic_read(&inode->i_count));
		return;
	}
	if (inode->i_nlink) {
		printk ("ext4_free_inode: inode has nlink=%d\n",
			inode->i_nlink);
		return;
	}
	if (!sb) {
		printk("ext4_free_inode: inode on nonexistent device\n");
		return;
	}
	sbi = EXT4_SB(sb);

	ino = inode->i_ino;
	ext4_debug ("freeing inode %lu\n", ino);

	/*
	 * Note: we must free any quota before locking the superblock,
	 * as writing the quota to disk may need the lock as well.
	 */
	DQUOT_INIT(inode);
	ext4_xattr_delete_inode(handle, inode);
	DQUOT_FREE_INODE(inode);
	DQUOT_DROP(inode);

	is_directory = S_ISDIR(inode->i_mode);

	/* Do this BEFORE marking the inode not in use or returning an error */
	clear_inode (inode);

	es = EXT4_SB(sb)->s_es;
	if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
		ext4_error (sb, "ext4_free_inode",
			    "reserved or nonexistent inode %lu", ino);
		goto error_return;
	}
	block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
	bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
	bitmap_bh = read_inode_bitmap(sb, block_group);
	if (!bitmap_bh)
		goto error_return;

	BUFFER_TRACE(bitmap_bh, "get_write_access");
	fatal = ext4_journal_get_write_access(handle, bitmap_bh);
	if (fatal)
		goto error_return;

	/* Ok, now we can actually update the inode bitmaps.. */
	if (!ext4_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
					bit, bitmap_bh->b_data))
		ext4_error (sb, "ext4_free_inode",
			      "bit already cleared for inode %lu", ino);
	else {
		gdp = ext4_get_group_desc (sb, block_group, &bh2);

		BUFFER_TRACE(bh2, "get_write_access");
		fatal = ext4_journal_get_write_access(handle, bh2);
		if (fatal) goto error_return;

		if (gdp) {
			spin_lock(sb_bgl_lock(sbi, block_group));
			gdp->bg_free_inodes_count = cpu_to_le16(
				le16_to_cpu(gdp->bg_free_inodes_count) + 1);
			if (is_directory)
				gdp->bg_used_dirs_count = cpu_to_le16(
				  le16_to_cpu(gdp->bg_used_dirs_count) - 1);
			spin_unlock(sb_bgl_lock(sbi, block_group));
			percpu_counter_inc(&sbi->s_freeinodes_counter);
			if (is_directory)
				percpu_counter_dec(&sbi->s_dirs_counter);

		}
		BUFFER_TRACE(bh2, "call ext4_journal_dirty_metadata");
		err = ext4_journal_dirty_metadata(handle, bh2);
		if (!fatal) fatal = err;
	}
	BUFFER_TRACE(bitmap_bh, "call ext4_journal_dirty_metadata");
	err = ext4_journal_dirty_metadata(handle, bitmap_bh);
	if (!fatal)
		fatal = err;
	sb->s_dirt = 1;
error_return:
	brelse(bitmap_bh);
	ext4_std_error(sb, fatal);
}
Esempio n. 13
0
/*
 * There are two policies for allocating an inode.  If the new inode is
 * a directory, then a forward search is made for a block group with both
 * free space and a low directory-to-inode ratio; if that fails, then of
 * the groups with above-average free space, that group with the fewest
 * directories already is chosen.
 *
 * For other inodes, search forward from the parent directory's block
 * group to find a free inode.
 */
struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode)
{
	struct super_block *sb;
	struct buffer_head *bitmap_bh = NULL;
	struct buffer_head *bh2;
	int group;
	unsigned long ino = 0;
	struct inode * inode;
	struct ext4_group_desc * gdp = NULL;
	struct ext4_super_block * es;
	struct ext4_inode_info *ei;
	struct ext4_sb_info *sbi;
	int err = 0;
	struct inode *ret;
	int i;

	/* Cannot create files in a deleted directory */
	if (!dir || !dir->i_nlink)
		return ERR_PTR(-EPERM);

	sb = dir->i_sb;
	inode = new_inode(sb);
	if (!inode)
		return ERR_PTR(-ENOMEM);
	ei = EXT4_I(inode);

	sbi = EXT4_SB(sb);
	es = sbi->s_es;
	if (S_ISDIR(mode)) {
		if (test_opt (sb, OLDALLOC))
			group = find_group_dir(sb, dir);
		else
			group = find_group_orlov(sb, dir);
	} else
		group = find_group_other(sb, dir);

	err = -ENOSPC;
	if (group == -1)
		goto out;

	for (i = 0; i < sbi->s_groups_count; i++) {
		err = -EIO;

		gdp = ext4_get_group_desc(sb, group, &bh2);
		if (!gdp)
			goto fail;

		brelse(bitmap_bh);
		bitmap_bh = read_inode_bitmap(sb, group);
		if (!bitmap_bh)
			goto fail;

		ino = 0;

repeat_in_this_group:
		ino = ext4_find_next_zero_bit((unsigned long *)
				bitmap_bh->b_data, EXT4_INODES_PER_GROUP(sb), ino);
		if (ino < EXT4_INODES_PER_GROUP(sb)) {

			BUFFER_TRACE(bitmap_bh, "get_write_access");
			err = ext4_journal_get_write_access(handle, bitmap_bh);
			if (err)
				goto fail;

			if (!ext4_set_bit_atomic(sb_bgl_lock(sbi, group),
						ino, bitmap_bh->b_data)) {
				/* we won it */
				BUFFER_TRACE(bitmap_bh,
					"call ext4_journal_dirty_metadata");
				err = ext4_journal_dirty_metadata(handle,
								bitmap_bh);
				if (err)
					goto fail;
				goto got;
			}
			/* we lost it */
			jbd2_journal_release_buffer(handle, bitmap_bh);

			if (++ino < EXT4_INODES_PER_GROUP(sb))
				goto repeat_in_this_group;
		}

		/*
		 * This case is possible in concurrent environment.  It is very
		 * rare.  We cannot repeat the find_group_xxx() call because
		 * that will simply return the same blockgroup, because the
		 * group descriptor metadata has not yet been updated.
		 * So we just go onto the next blockgroup.
		 */
		if (++group == sbi->s_groups_count)
			group = 0;
	}
	err = -ENOSPC;
	goto out;

got:
	ino += group * EXT4_INODES_PER_GROUP(sb) + 1;
	if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
		ext4_error (sb, "ext4_new_inode",
			    "reserved inode or inode > inodes count - "
			    "block_group = %d, inode=%lu", group, ino);
		err = -EIO;
		goto fail;
	}

	BUFFER_TRACE(bh2, "get_write_access");
	err = ext4_journal_get_write_access(handle, bh2);
	if (err) goto fail;
	spin_lock(sb_bgl_lock(sbi, group));
	gdp->bg_free_inodes_count =
		cpu_to_le16(le16_to_cpu(gdp->bg_free_inodes_count) - 1);
	if (S_ISDIR(mode)) {
		gdp->bg_used_dirs_count =
			cpu_to_le16(le16_to_cpu(gdp->bg_used_dirs_count) + 1);
	}
	spin_unlock(sb_bgl_lock(sbi, group));
	BUFFER_TRACE(bh2, "call ext4_journal_dirty_metadata");
	err = ext4_journal_dirty_metadata(handle, bh2);
	if (err) goto fail;

	percpu_counter_dec(&sbi->s_freeinodes_counter);
	if (S_ISDIR(mode))
		percpu_counter_inc(&sbi->s_dirs_counter);
	sb->s_dirt = 1;

	inode->i_uid = current->fsuid;
	if (test_opt (sb, GRPID))
		inode->i_gid = dir->i_gid;
	else if (dir->i_mode & S_ISGID) {
		inode->i_gid = dir->i_gid;
		if (S_ISDIR(mode))
			mode |= S_ISGID;
	} else
		inode->i_gid = current->fsgid;
	inode->i_mode = mode;

	inode->i_ino = ino;
	/* This is the optimal IO size (for stat), not the fs block size */
	inode->i_blocks = 0;
	inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
						       ext4_current_time(inode);

	memset(ei->i_data, 0, sizeof(ei->i_data));
	ei->i_dir_start_lookup = 0;
	ei->i_disksize = 0;

	ei->i_flags = EXT4_I(dir)->i_flags & ~EXT4_INDEX_FL;
	if (S_ISLNK(mode))
		ei->i_flags &= ~(EXT4_IMMUTABLE_FL|EXT4_APPEND_FL);
	/* dirsync only applies to directories */
	if (!S_ISDIR(mode))
		ei->i_flags &= ~EXT4_DIRSYNC_FL;
#ifdef EXT4_FRAGMENTS
	ei->i_faddr = 0;
	ei->i_frag_no = 0;
	ei->i_frag_size = 0;
#endif
	ei->i_file_acl = 0;
	ei->i_dir_acl = 0;
	ei->i_dtime = 0;
	ei->i_block_alloc_info = NULL;
	ei->i_block_group = group;

	ext4_set_inode_flags(inode);
	if (IS_DIRSYNC(inode))
		handle->h_sync = 1;
	insert_inode_hash(inode);
	spin_lock(&sbi->s_next_gen_lock);
	inode->i_generation = sbi->s_next_generation++;
	spin_unlock(&sbi->s_next_gen_lock);

	ei->i_state = EXT4_STATE_NEW;

	ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;

	ret = inode;
	if(DQUOT_ALLOC_INODE(inode)) {
		err = -EDQUOT;
		goto fail_drop;
	}

	err = ext4_init_acl(handle, inode, dir);
	if (err)
		goto fail_free_drop;

	err = ext4_init_security(handle,inode, dir);
	if (err)
		goto fail_free_drop;

	err = ext4_mark_inode_dirty(handle, inode);
	if (err) {
		ext4_std_error(sb, err);
		goto fail_free_drop;
	}
	if (test_opt(sb, EXTENTS)) {
		EXT4_I(inode)->i_flags |= EXT4_EXTENTS_FL;
		ext4_ext_tree_init(handle, inode);
		if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
			err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
			if (err) goto fail;
			EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS);
			BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "call ext4_journal_dirty_metadata");
			err = ext4_journal_dirty_metadata(handle, EXT4_SB(sb)->s_sbh);
		}
	}

	ext4_debug("allocating inode %lu\n", inode->i_ino);
	goto really_out;
fail:
	ext4_std_error(sb, err);
out:
	iput(inode);
	ret = ERR_PTR(err);
really_out:
	brelse(bitmap_bh);
	return ret;

fail_free_drop:
	DQUOT_FREE_INODE(inode);

fail_drop:
	DQUOT_DROP(inode);
	inode->i_flags |= S_NOQUOTA;
	inode->i_nlink = 0;
	iput(inode);
	brelse(bitmap_bh);
	return ERR_PTR(err);
}
Esempio n. 14
0
static int find_group_orlov(struct super_block *sb, struct inode *parent)
{
	int parent_group = EXT4_I(parent)->i_block_group;
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_super_block *es = sbi->s_es;
	int ngroups = sbi->s_groups_count;
	int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
	unsigned int freei, avefreei;
	ext4_fsblk_t freeb, avefreeb;
	ext4_fsblk_t blocks_per_dir;
	unsigned int ndirs;
	int max_debt, max_dirs, min_inodes;
	ext4_grpblk_t min_blocks;
	int group = -1, i;
	struct ext4_group_desc *desc;
	struct buffer_head *bh;

	freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
	avefreei = freei / ngroups;
	freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
	avefreeb = freeb;
	do_div(avefreeb, ngroups);
	ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);

	if ((parent == sb->s_root->d_inode) ||
	    (EXT4_I(parent)->i_flags & EXT4_TOPDIR_FL)) {
		int best_ndir = inodes_per_group;
		int best_group = -1;

		get_random_bytes(&group, sizeof(group));
		parent_group = (unsigned)group % ngroups;
		for (i = 0; i < ngroups; i++) {
			group = (parent_group + i) % ngroups;
			desc = ext4_get_group_desc (sb, group, &bh);
			if (!desc || !desc->bg_free_inodes_count)
				continue;
			if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
				continue;
			if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
				continue;
			if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
				continue;
			best_group = group;
			best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
		}
		if (best_group >= 0)
			return best_group;
		goto fallback;
	}

	blocks_per_dir = ext4_blocks_count(es) - freeb;
	do_div(blocks_per_dir, ndirs);

	max_dirs = ndirs / ngroups + inodes_per_group / 16;
	min_inodes = avefreei - inodes_per_group / 4;
	min_blocks = avefreeb - EXT4_BLOCKS_PER_GROUP(sb) / 4;

	max_debt = EXT4_BLOCKS_PER_GROUP(sb);
	max_debt /= max_t(int, blocks_per_dir, BLOCK_COST);
	if (max_debt * INODE_COST > inodes_per_group)
		max_debt = inodes_per_group / INODE_COST;
	if (max_debt > 255)
		max_debt = 255;
	if (max_debt == 0)
		max_debt = 1;

	for (i = 0; i < ngroups; i++) {
		group = (parent_group + i) % ngroups;
		desc = ext4_get_group_desc (sb, group, &bh);
		if (!desc || !desc->bg_free_inodes_count)
			continue;
		if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
			continue;
		if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
			continue;
		if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
			continue;
		return group;
	}

fallback:
	for (i = 0; i < ngroups; i++) {
		group = (parent_group + i) % ngroups;
		desc = ext4_get_group_desc (sb, group, &bh);
		if (!desc || !desc->bg_free_inodes_count)
			continue;
		if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
			return group;
	}

	if (avefreei) {
		/*
		 * The free-inodes counter is approximate, and for really small
		 * filesystems the above test can fail to find any blockgroups
		 */
		avefreei = 0;
		goto fallback;
	}

	return -1;
}