[net-next-2.6.git] / fs / ext4 / migrate.c

/*
 * Copyright IBM Corporation, 2007
 * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2.1 of the GNU Lesser General Public License
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 */

#include <linux/module.h>
#include <linux/slab.h>
#include "ext4_jbd2.h"
#include "ext4_extents.h"

/*
 * The contiguous blocks details which can be
 * represented by a single extent
 */
struct list_blocks_struct {
	ext4_lblk_t first_block, last_block;
	ext4_fsblk_t first_pblock, last_pblock;
};

static int finish_range(handle_t *handle, struct inode *inode,
				struct list_blocks_struct *lb)

{
	int retval = 0, needed;
	struct ext4_extent newext;
	struct ext4_ext_path *path;
	if (lb->first_pblock == 0)
		return 0;

	/* Add the extent to temp inode*/
	newext.ee_block = cpu_to_le32(lb->first_block);
	newext.ee_len   = cpu_to_le16(lb->last_block - lb->first_block + 1);
	ext4_ext_store_pblock(&newext, lb->first_pblock);
	path = ext4_ext_find_extent(inode, lb->first_block, NULL);

	if (IS_ERR(path)) {
		retval = PTR_ERR(path);
		path = NULL;
		goto err_out;
	}

	/*
	 * Calculate the credit needed to inserting this extent
	 * Since we are doing this in loop we may accumalate extra
	 * credit. But below we try to not accumalate too much
	 * of them by restarting the journal.
	 */
	needed = ext4_ext_calc_credits_for_single_extent(inode,
		    lb->last_block - lb->first_block + 1, path);

	/*
	 * Make sure the credit we accumalated is not really high
	 */
	if (needed && ext4_handle_has_enough_credits(handle,
						EXT4_RESERVE_TRANS_BLOCKS)) {
		retval = ext4_journal_restart(handle, needed);
		if (retval)
			goto err_out;
	} else if (needed) {
		retval = ext4_journal_extend(handle, needed);
		if (retval) {
			/*
			 * IF not able to extend the journal restart the journal
			 */
			retval = ext4_journal_restart(handle, needed);
			if (retval)
				goto err_out;
		}
	}
	retval = ext4_ext_insert_extent(handle, inode, path, &newext, 0);
err_out:
	if (path) {
		ext4_ext_drop_refs(path);
		kfree(path);
	}
	lb->first_pblock = 0;
	return retval;
}

static int update_extent_range(handle_t *handle, struct inode *inode,
				ext4_fsblk_t pblock, ext4_lblk_t blk_num,
				struct list_blocks_struct *lb)
{
	int retval;
	/*
	 * See if we can add on to the existing range (if it exists)
	 */
	if (lb->first_pblock &&
		(lb->last_pblock+1 == pblock) &&
		(lb->last_block+1 == blk_num)) {
		lb->last_pblock = pblock;
		lb->last_block = blk_num;
		return 0;
	}
	/*
	 * Start a new range.
	 */
	retval = finish_range(handle, inode, lb);
	lb->first_pblock = lb->last_pblock = pblock;
	lb->first_block = lb->last_block = blk_num;

	return retval;
}

static int update_ind_extent_range(handle_t *handle, struct inode *inode,
				   ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
				   struct list_blocks_struct *lb)
{
	struct buffer_head *bh;
	__le32 *i_data;
	int i, retval = 0;
	ext4_lblk_t blk_count = *blk_nump;
	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;

	if (!pblock) {
		/* Only update the file block number */
		*blk_nump += max_entries;
		return 0;
	}

	bh = sb_bread(inode->i_sb, pblock);
	if (!bh)
		return -EIO;

	i_data = (__le32 *)bh->b_data;
	for (i = 0; i < max_entries; i++, blk_count++) {
		if (i_data[i]) {
			retval = update_extent_range(handle, inode,
						le32_to_cpu(i_data[i]),
						blk_count, lb);
			if (retval)
				break;
		}
	}

	/* Update the file block number */
	*blk_nump = blk_count;
	put_bh(bh);
	return retval;

}

static int update_dind_extent_range(handle_t *handle, struct inode *inode,
				    ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
				    struct list_blocks_struct *lb)
{
	struct buffer_head *bh;
	__le32 *i_data;
	int i, retval = 0;
	ext4_lblk_t blk_count = *blk_nump;
	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;

	if (!pblock) {
		/* Only update the file block number */
		*blk_nump += max_entries * max_entries;
		return 0;
	}
	bh = sb_bread(inode->i_sb, pblock);
	if (!bh)
		return -EIO;

	i_data = (__le32 *)bh->b_data;
	for (i = 0; i < max_entries; i++) {
		if (i_data[i]) {
			retval = update_ind_extent_range(handle, inode,
						le32_to_cpu(i_data[i]),
						&blk_count, lb);
			if (retval)
				break;
		} else {
			/* Only update the file block number */
			blk_count += max_entries;
		}
	}

	/* Update the file block number */
	*blk_nump = blk_count;
	put_bh(bh);
	return retval;

}

static int update_tind_extent_range(handle_t *handle, struct inode *inode,
				     ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
				     struct list_blocks_struct *lb)
{
	struct buffer_head *bh;
	__le32 *i_data;
	int i, retval = 0;
	ext4_lblk_t blk_count = *blk_nump;
	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;

	if (!pblock) {
		/* Only update the file block number */
		*blk_nump += max_entries * max_entries * max_entries;
		return 0;
	}
	bh = sb_bread(inode->i_sb, pblock);
	if (!bh)
		return -EIO;

	i_data = (__le32 *)bh->b_data;
	for (i = 0; i < max_entries; i++) {
		if (i_data[i]) {
			retval = update_dind_extent_range(handle, inode,
						le32_to_cpu(i_data[i]),
						&blk_count, lb);
			if (retval)
				break;
		} else
			/* Only update the file block number */
			blk_count += max_entries * max_entries;
	}
	/* Update the file block number */
	*blk_nump = blk_count;
	put_bh(bh);
	return retval;

}

static int extend_credit_for_blkdel(handle_t *handle, struct inode *inode)
{
	int retval = 0, needed;

	if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
		return 0;
	/*
	 * We are freeing a blocks. During this we touch
	 * superblock, group descriptor and block bitmap.
	 * So allocate a credit of 3. We may update
	 * quota (user and group).
	 */
	needed = 3 + EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);

	if (ext4_journal_extend(handle, needed) != 0)
		retval = ext4_journal_restart(handle, needed);

	return retval;
}

static int free_dind_blocks(handle_t *handle,
				struct inode *inode, __le32 i_data)
{
	int i;
	__le32 *tmp_idata;
	struct buffer_head *bh;
	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;

	bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
	if (!bh)
		return -EIO;

	tmp_idata = (__le32 *)bh->b_data;
	for (i = 0; i < max_entries; i++) {
		if (tmp_idata[i]) {
			extend_credit_for_blkdel(handle, inode);
			ext4_free_blocks(handle, inode, 0,
					 le32_to_cpu(tmp_idata[i]), 1,
					 EXT4_FREE_BLOCKS_METADATA |
					 EXT4_FREE_BLOCKS_FORGET);
		}
	}
	put_bh(bh);
	extend_credit_for_blkdel(handle, inode);
	ext4_free_blocks(handle, inode, 0, le32_to_cpu(i_data), 1,
			 EXT4_FREE_BLOCKS_METADATA |
			 EXT4_FREE_BLOCKS_FORGET);
	return 0;
}

static int free_tind_blocks(handle_t *handle,
				struct inode *inode, __le32 i_data)
{
	int i, retval = 0;
	__le32 *tmp_idata;
	struct buffer_head *bh;
	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;

	bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
	if (!bh)
		return -EIO;

	tmp_idata = (__le32 *)bh->b_data;
	for (i = 0; i < max_entries; i++) {
		if (tmp_idata[i]) {
			retval = free_dind_blocks(handle,
					inode, tmp_idata[i]);
			if (retval) {
				put_bh(bh);
				return retval;
			}
		}
	}
	put_bh(bh);
	extend_credit_for_blkdel(handle, inode);
	ext4_free_blocks(handle, inode, 0, le32_to_cpu(i_data), 1,
			 EXT4_FREE_BLOCKS_METADATA |
			 EXT4_FREE_BLOCKS_FORGET);
	return 0;
}

static int free_ind_block(handle_t *handle, struct inode *inode, __le32 *i_data)
{
	int retval;

	/* ei->i_data[EXT4_IND_BLOCK] */
	if (i_data[0]) {
		extend_credit_for_blkdel(handle, inode);
		ext4_free_blocks(handle, inode, 0,
				le32_to_cpu(i_data[0]), 1,
				 EXT4_FREE_BLOCKS_METADATA |
				 EXT4_FREE_BLOCKS_FORGET);
	}

	/* ei->i_data[EXT4_DIND_BLOCK] */
	if (i_data[1]) {
		retval = free_dind_blocks(handle, inode, i_data[1]);
		if (retval)
			return retval;
	}

	/* ei->i_data[EXT4_TIND_BLOCK] */
	if (i_data[2]) {
		retval = free_tind_blocks(handle, inode, i_data[2]);
		if (retval)
			return retval;
	}
	return 0;
}

static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
						struct inode *tmp_inode)
{
	int retval;
	__le32	i_data[3];
	struct ext4_inode_info *ei = EXT4_I(inode);
	struct ext4_inode_info *tmp_ei = EXT4_I(tmp_inode);

	/*
	 * One credit accounted for writing the
	 * i_data field of the original inode
	 */
	retval = ext4_journal_extend(handle, 1);
	if (retval) {
		retval = ext4_journal_restart(handle, 1);
		if (retval)
			goto err_out;
	}

	i_data[0] = ei->i_data[EXT4_IND_BLOCK];
	i_data[1] = ei->i_data[EXT4_DIND_BLOCK];
	i_data[2] = ei->i_data[EXT4_TIND_BLOCK];

	down_write(&EXT4_I(inode)->i_data_sem);
	/*
	 * if EXT4_STATE_EXT_MIGRATE is cleared a block allocation
	 * happened after we started the migrate. We need to
	 * fail the migrate
	 */
	if (!ext4_test_inode_state(inode, EXT4_STATE_EXT_MIGRATE)) {
		retval = -EAGAIN;
		up_write(&EXT4_I(inode)->i_data_sem);
		goto err_out;
	} else
		ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
	/*
	 * We have the extent map build with the tmp inode.
	 * Now copy the i_data across
	 */
	ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS);
	memcpy(ei->i_data, tmp_ei->i_data, sizeof(ei->i_data));

	/*
	 * Update i_blocks with the new blocks that got
	 * allocated while adding extents for extent index
	 * blocks.
	 *
	 * While converting to extents we need not
	 * update the orignal inode i_blocks for extent blocks
	 * via quota APIs. The quota update happened via tmp_inode already.
	 */
	spin_lock(&inode->i_lock);
	inode->i_blocks += tmp_inode->i_blocks;
	spin_unlock(&inode->i_lock);
	up_write(&EXT4_I(inode)->i_data_sem);

	/*
	 * We mark the inode dirty after, because we decrement the
	 * i_blocks when freeing the indirect meta-data blocks
	 */
	retval = free_ind_block(handle, inode, i_data);
	ext4_mark_inode_dirty(handle, inode);

err_out:
	return retval;
}

static int free_ext_idx(handle_t *handle, struct inode *inode,
					struct ext4_extent_idx *ix)
{
	int i, retval = 0;
	ext4_fsblk_t block;
	struct buffer_head *bh;
	struct ext4_extent_header *eh;

	block = ext4_idx_pblock(ix);
	bh = sb_bread(inode->i_sb, block);
	if (!bh)
		return -EIO;

	eh = (struct ext4_extent_header *)bh->b_data;
	if (eh->eh_depth != 0) {
		ix = EXT_FIRST_INDEX(eh);
		for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
			retval = free_ext_idx(handle, inode, ix);
			if (retval)
				break;
		}
	}
	put_bh(bh);
	extend_credit_for_blkdel(handle, inode);
	ext4_free_blocks(handle, inode, 0, block, 1,
			 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
	return retval;
}

/*
 * Free the extent meta data blocks only
 */
static int free_ext_block(handle_t *handle, struct inode *inode)
{
	int i, retval = 0;
	struct ext4_inode_info *ei = EXT4_I(inode);
	struct ext4_extent_header *eh = (struct ext4_extent_header *)ei->i_data;
	struct ext4_extent_idx *ix;
	if (eh->eh_depth == 0)
		/*
		 * No extra blocks allocated for extent meta data
		 */
		return 0;
	ix = EXT_FIRST_INDEX(eh);
	for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
		retval = free_ext_idx(handle, inode, ix);
		if (retval)
			return retval;
	}
	return retval;

}

int ext4_ext_migrate(struct inode *inode)
{
	handle_t *handle;
	int retval = 0, i;
	__le32 *i_data;
	ext4_lblk_t blk_count = 0;
	struct ext4_inode_info *ei;
	struct inode *tmp_inode = NULL;
	struct list_blocks_struct lb;
	unsigned long max_entries;
	__u32 goal;

	/*
	 * If the filesystem does not support extents, or the inode
	 * already is extent-based, error out.
	 */
	if (!EXT4_HAS_INCOMPAT_FEATURE(inode->i_sb,
				       EXT4_FEATURE_INCOMPAT_EXTENTS) ||
	    (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
		return -EINVAL;

	if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0)
		/*
		 * don't migrate fast symlink
		 */
		return retval;

	handle = ext4_journal_start(inode,
					EXT4_DATA_TRANS_BLOCKS(inode->i_sb) +
					EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
					EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)
					+ 1);
	if (IS_ERR(handle)) {
		retval = PTR_ERR(handle);
		return retval;
	}
	goal = (((inode->i_ino - 1) / EXT4_INODES_PER_GROUP(inode->i_sb)) *
		EXT4_INODES_PER_GROUP(inode->i_sb)) + 1;
	tmp_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
				   S_IFREG, 0, goal);
	if (IS_ERR(tmp_inode)) {
		retval = -ENOMEM;
		ext4_journal_stop(handle);
		return retval;
	}
	i_size_write(tmp_inode, i_size_read(inode));
	/*
	 * Set the i_nlink to zero so it will be deleted later
	 * when we drop inode reference.
	 */
	tmp_inode->i_nlink = 0;

	ext4_ext_tree_init(handle, tmp_inode);
	ext4_orphan_add(handle, tmp_inode);
	ext4_journal_stop(handle);

	/*
	 * start with one credit accounted for
	 * superblock modification.
	 *
	 * For the tmp_inode we already have commited the
	 * trascation that created the inode. Later as and
	 * when we add extents we extent the journal
	 */
	/*
	 * Even though we take i_mutex we can still cause block
	 * allocation via mmap write to holes. If we have allocated
	 * new blocks we fail migrate.  New block allocation will
	 * clear EXT4_STATE_EXT_MIGRATE flag.  The flag is updated
	 * with i_data_sem held to prevent racing with block
	 * allocation.
	 */
	down_read((&EXT4_I(inode)->i_data_sem));
	ext4_set_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
	up_read((&EXT4_I(inode)->i_data_sem));

	handle = ext4_journal_start(inode, 1);
	if (IS_ERR(handle)) {
		/*
		 * It is impossible to update on-disk structures without
		 * a handle, so just rollback in-core changes and live other
		 * work to orphan_list_cleanup()
		 */
		ext4_orphan_del(NULL, tmp_inode);
		retval = PTR_ERR(handle);
		goto out;
	}

	ei = EXT4_I(inode);
	i_data = ei->i_data;
	memset(&lb, 0, sizeof(lb));

	/* 32 bit block address 4 bytes */
	max_entries = inode->i_sb->s_blocksize >> 2;
	for (i = 0; i < EXT4_NDIR_BLOCKS; i++, blk_count++) {
		if (i_data[i]) {
			retval = update_extent_range(handle, tmp_inode,
						le32_to_cpu(i_data[i]),
						blk_count, &lb);
			if (retval)
				goto err_out;
		}
	}
	if (i_data[EXT4_IND_BLOCK]) {
		retval = update_ind_extent_range(handle, tmp_inode,
					le32_to_cpu(i_data[EXT4_IND_BLOCK]),
					&blk_count, &lb);
			if (retval)
				goto err_out;
	} else
		blk_count +=  max_entries;
	if (i_data[EXT4_DIND_BLOCK]) {
		retval = update_dind_extent_range(handle, tmp_inode,
					le32_to_cpu(i_data[EXT4_DIND_BLOCK]),
					&blk_count, &lb);
			if (retval)
				goto err_out;
	} else
		blk_count += max_entries * max_entries;
	if (i_data[EXT4_TIND_BLOCK]) {
		retval = update_tind_extent_range(handle, tmp_inode,
					le32_to_cpu(i_data[EXT4_TIND_BLOCK]),
					&blk_count, &lb);
			if (retval)
				goto err_out;
	}
	/*
	 * Build the last extent
	 */
	retval = finish_range(handle, tmp_inode, &lb);
err_out:
	if (retval)
		/*
		 * Failure case delete the extent information with the
		 * tmp_inode
		 */
		free_ext_block(handle, tmp_inode);
	else {
		retval = ext4_ext_swap_inode_data(handle, inode, tmp_inode);
		if (retval)
			/*
			 * if we fail to swap inode data free the extent
			 * details of the tmp inode
			 */
			free_ext_block(handle, tmp_inode);
	}

	/* We mark the tmp_inode dirty via ext4_ext_tree_init. */
	if (ext4_journal_extend(handle, 1) != 0)
		ext4_journal_restart(handle, 1);

	/*
	 * Mark the tmp_inode as of size zero
	 */
	i_size_write(tmp_inode, 0);

	/*
	 * set the  i_blocks count to zero
	 * so that the ext4_delete_inode does the
	 * right job
	 *
	 * We don't need to take the i_lock because
	 * the inode is not visible to user space.
	 */
	tmp_inode->i_blocks = 0;

	/* Reset the extent details */
	ext4_ext_tree_init(handle, tmp_inode);
	ext4_journal_stop(handle);
out:
	unlock_new_inode(tmp_inode);
	iput(tmp_inode);

	return retval;
}
Commit	Line	Data
c14c6fd5 AK	1	/*
	2	* Copyright IBM Corporation, 2007
	3	* Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms of version 2.1 of the GNU Lesser General Public License
	7	* as published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope that it would be useful, but
	10	* WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
	12	*
	13	*/
	14
	15	#include <linux/module.h>
5a0e3ad6	16	#include <linux/slab.h>
3dcf5451 CH	17	#include "ext4_jbd2.h"
3dcf5451 CH	18	#include "ext4_extents.h"
c14c6fd5 AK	19
	20	/*
	21	* The contiguous blocks details which can be
	22	* represented by a single extent
	23	*/
	24	struct list_blocks_struct {
	25	ext4_lblk_t first_block, last_block;
	26	ext4_fsblk_t first_pblock, last_pblock;
	27	};
	28
	29	static int finish_range(handle_t handle, struct inode inode,
	30	struct list_blocks_struct *lb)
	31
	32	{
	33	int retval = 0, needed;
	34	struct ext4_extent newext;
	35	struct ext4_ext_path *path;
	36	if (lb->first_pblock == 0)
	37	return 0;
	38
	39	/* Add the extent to temp inode*/
	40	newext.ee_block = cpu_to_le32(lb->first_block);
	41	newext.ee_len = cpu_to_le16(lb->last_block - lb->first_block + 1);
	42	ext4_ext_store_pblock(&newext, lb->first_pblock);
	43	path = ext4_ext_find_extent(inode, lb->first_block, NULL);
	44
	45	if (IS_ERR(path)) {
	46	retval = PTR_ERR(path);
b35905c1	47	path = NULL;
c14c6fd5 AK	48	goto err_out;
	49	}
	50
	51	/*
	52	* Calculate the credit needed to inserting this extent
	53	* Since we are doing this in loop we may accumalate extra
	54	* credit. But below we try to not accumalate too much
	55	* of them by restarting the journal.
	56	*/
ee12b630 MC	57	needed = ext4_ext_calc_credits_for_single_extent(inode,
ee12b630 MC	58	lb->last_block - lb->first_block + 1, path);
c14c6fd5 AK	59
	60	/*
	61	* Make sure the credit we accumalated is not really high
	62	*/
0390131b FM	63	if (needed && ext4_handle_has_enough_credits(handle,
0390131b FM	64	EXT4_RESERVE_TRANS_BLOCKS)) {
c14c6fd5 AK	65	retval = ext4_journal_restart(handle, needed);
	66	if (retval)
	67	goto err_out;
8009f9fb	68	} else if (needed) {
c14c6fd5	69	retval = ext4_journal_extend(handle, needed);
8009f9fb	70	if (retval) {
c14c6fd5 AK	71	/*
	72	* IF not able to extend the journal restart the journal
	73	*/
	74	retval = ext4_journal_restart(handle, needed);
	75	if (retval)
	76	goto err_out;
	77	}
	78	}
0031462b	79	retval = ext4_ext_insert_extent(handle, inode, path, &newext, 0);
c14c6fd5	80	err_out:
b35905c1 AK	81	if (path) {
	82	ext4_ext_drop_refs(path);
	83	kfree(path);
	84	}
c14c6fd5 AK	85	lb->first_pblock = 0;
	86	return retval;
	87	}
	88
	89	static int update_extent_range(handle_t handle, struct inode inode,
	90	ext4_fsblk_t pblock, ext4_lblk_t blk_num,
	91	struct list_blocks_struct *lb)
	92	{
	93	int retval;
	94	/*
	95	* See if we can add on to the existing range (if it exists)
	96	*/
	97	if (lb->first_pblock &&
	98	(lb->last_pblock+1 == pblock) &&
	99	(lb->last_block+1 == blk_num)) {
	100	lb->last_pblock = pblock;
	101	lb->last_block = blk_num;
	102	return 0;
	103	}
	104	/*
	105	* Start a new range.
	106	*/
	107	retval = finish_range(handle, inode, lb);
	108	lb->first_pblock = lb->last_pblock = pblock;
	109	lb->first_block = lb->last_block = blk_num;
	110
	111	return retval;
	112	}
	113
	114	static int update_ind_extent_range(handle_t handle, struct inode inode,
	115	ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
	116	struct list_blocks_struct *lb)
	117	{
	118	struct buffer_head *bh;
	119	__le32 *i_data;
	120	int i, retval = 0;
	121	ext4_lblk_t blk_count = *blk_nump;
	122	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
	123
	124	if (!pblock) {
	125	/* Only update the file block number */
	126	*blk_nump += max_entries;
	127	return 0;
	128	}
	129
	130	bh = sb_bread(inode->i_sb, pblock);
	131	if (!bh)
	132	return -EIO;
	133
	134	i_data = (__le32 *)bh->b_data;
	135	for (i = 0; i < max_entries; i++, blk_count++) {
	136	if (i_data[i]) {
	137	retval = update_extent_range(handle, inode,
	138	le32_to_cpu(i_data[i]),
	139	blk_count, lb);
	140	if (retval)
	141	break;
	142	}
	143	}
	144
	145	/* Update the file block number */
	146	*blk_nump = blk_count;
	147	put_bh(bh);
	148	return retval;
149
150	}
151
152	static int update_dind_extent_range(handle_t handle, struct inode inode,
153	ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
154	struct list_blocks_struct *lb)
155	{
156	struct buffer_head *bh;
157	__le32 *i_data;
158	int i, retval = 0;
159	ext4_lblk_t blk_count = *blk_nump;
160	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
161
162	if (!pblock) {
163	/* Only update the file block number */
164	blk_nump += max_entries max_entries;
165	return 0;
166	}
167	bh = sb_bread(inode->i_sb, pblock);
168	if (!bh)
169	return -EIO;
170
171	i_data = (__le32 *)bh->b_data;
172	for (i = 0; i < max_entries; i++) {
173	if (i_data[i]) {
174	retval = update_ind_extent_range(handle, inode,
175	le32_to_cpu(i_data[i]),
176	&blk_count, lb);
177	if (retval)
178	break;
179	} else {
180	/* Only update the file block number */
181	blk_count += max_entries;
182	}
183	}
184
185	/* Update the file block number */
186	*blk_nump = blk_count;
187	put_bh(bh);
188	return retval;
189
190	}
191
192	static int update_tind_extent_range(handle_t handle, struct inode inode,
193	ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
194	struct list_blocks_struct *lb)
195	{
196	struct buffer_head *bh;
197	__le32 *i_data;
198	int i, retval = 0;
199	ext4_lblk_t blk_count = *blk_nump;
200	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
201
202	if (!pblock) {
203	/* Only update the file block number */
204	blk_nump += max_entries max_entries * max_entries;
205	return 0;
206	}
207	bh = sb_bread(inode->i_sb, pblock);
208	if (!bh)
209	return -EIO;
210
211	i_data = (__le32 *)bh->b_data;
212	for (i = 0; i < max_entries; i++) {
213	if (i_data[i]) {
214	retval = update_dind_extent_range(handle, inode,
215	le32_to_cpu(i_data[i]),
216	&blk_count, lb);
217	if (retval)
218	break;
219	} else
220	/* Only update the file block number */
221	blk_count += max_entries * max_entries;
222	}
223	/* Update the file block number */
224	*blk_nump = blk_count;
225	put_bh(bh);
226	return retval;
227
228	}
229
8009f9fb AK	230	static int extend_credit_for_blkdel(handle_t handle, struct inode inode)
	231	{
	232	int retval = 0, needed;
	233
0390131b	234	if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
8009f9fb AK	235	return 0;
	236	/*
	237	* We are freeing a blocks. During this we touch
	238	* superblock, group descriptor and block bitmap.
	239	* So allocate a credit of 3. We may update
	240	* quota (user and group).
	241	*/
5aca07eb	242	needed = 3 + EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
8009f9fb AK	243
	244	if (ext4_journal_extend(handle, needed) != 0)
	245	retval = ext4_journal_restart(handle, needed);
	246
	247	return retval;
	248	}
	249
c14c6fd5 AK	250	static int free_dind_blocks(handle_t *handle,
	251	struct inode *inode, __le32 i_data)
	252	{
	253	int i;
	254	__le32 *tmp_idata;
	255	struct buffer_head *bh;
	256	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
	257
	258	bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
	259	if (!bh)
	260	return -EIO;
	261
	262	tmp_idata = (__le32 *)bh->b_data;
	263	for (i = 0; i < max_entries; i++) {
8009f9fb AK	264	if (tmp_idata[i]) {
8009f9fb AK	265	extend_credit_for_blkdel(handle, inode);
e6362609 TT	266	ext4_free_blocks(handle, inode, 0,
	267	le32_to_cpu(tmp_idata[i]), 1,
	268	EXT4_FREE_BLOCKS_METADATA \|
	269	EXT4_FREE_BLOCKS_FORGET);
8009f9fb	270	}
c14c6fd5 AK	271	}
c14c6fd5 AK	272	put_bh(bh);
8009f9fb	273	extend_credit_for_blkdel(handle, inode);
e6362609 TT	274	ext4_free_blocks(handle, inode, 0, le32_to_cpu(i_data), 1,
	275	EXT4_FREE_BLOCKS_METADATA \|
	276	EXT4_FREE_BLOCKS_FORGET);
c14c6fd5 AK	277	return 0;
	278	}
	279
	280	static int free_tind_blocks(handle_t *handle,
	281	struct inode *inode, __le32 i_data)
	282	{
	283	int i, retval = 0;
	284	__le32 *tmp_idata;
	285	struct buffer_head *bh;
	286	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
	287
	288	bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
	289	if (!bh)
	290	return -EIO;
	291
	292	tmp_idata = (__le32 *)bh->b_data;
	293	for (i = 0; i < max_entries; i++) {
	294	if (tmp_idata[i]) {
	295	retval = free_dind_blocks(handle,
	296	inode, tmp_idata[i]);
	297	if (retval) {
	298	put_bh(bh);
	299	return retval;
	300	}
	301	}
	302	}
	303	put_bh(bh);
8009f9fb	304	extend_credit_for_blkdel(handle, inode);
e6362609 TT	305	ext4_free_blocks(handle, inode, 0, le32_to_cpu(i_data), 1,
	306	EXT4_FREE_BLOCKS_METADATA \|
	307	EXT4_FREE_BLOCKS_FORGET);
c14c6fd5 AK	308	return 0;
	309	}
	310
8009f9fb	311	static int free_ind_block(handle_t handle, struct inode inode, __le32 *i_data)
c14c6fd5 AK	312	{
c14c6fd5 AK	313	int retval;
c14c6fd5	314
8009f9fb AK	315	/* ei->i_data[EXT4_IND_BLOCK] */
	316	if (i_data[0]) {
	317	extend_credit_for_blkdel(handle, inode);
e6362609 TT	318	ext4_free_blocks(handle, inode, 0,
	319	le32_to_cpu(i_data[0]), 1,
	320	EXT4_FREE_BLOCKS_METADATA \|
	321	EXT4_FREE_BLOCKS_FORGET);
8009f9fb	322	}
c14c6fd5	323
8009f9fb AK	324	/* ei->i_data[EXT4_DIND_BLOCK] */
	325	if (i_data[1]) {
	326	retval = free_dind_blocks(handle, inode, i_data[1]);
c14c6fd5 AK	327	if (retval)
	328	return retval;
	329	}
	330
8009f9fb AK	331	/* ei->i_data[EXT4_TIND_BLOCK] */
	332	if (i_data[2]) {
	333	retval = free_tind_blocks(handle, inode, i_data[2]);
c14c6fd5 AK	334	if (retval)
	335	return retval;
	336	}
	337	return 0;
	338	}
	339
	340	static int ext4_ext_swap_inode_data(handle_t handle, struct inode inode,
267e4db9	341	struct inode *tmp_inode)
c14c6fd5	342	{
8009f9fb AK	343	int retval;
8009f9fb AK	344	__le32 i_data[3];
c14c6fd5 AK	345	struct ext4_inode_info *ei = EXT4_I(inode);
	346	struct ext4_inode_info *tmp_ei = EXT4_I(tmp_inode);
	347
c14c6fd5 AK	348	/*
	349	* One credit accounted for writing the
	350	* i_data field of the original inode
	351	*/
	352	retval = ext4_journal_extend(handle, 1);
267e4db9	353	if (retval) {
c14c6fd5 AK	354	retval = ext4_journal_restart(handle, 1);
	355	if (retval)
	356	goto err_out;
	357	}
	358
8009f9fb AK	359	i_data[0] = ei->i_data[EXT4_IND_BLOCK];
	360	i_data[1] = ei->i_data[EXT4_DIND_BLOCK];
	361	i_data[2] = ei->i_data[EXT4_TIND_BLOCK];
	362
	363	down_write(&EXT4_I(inode)->i_data_sem);
267e4db9	364	/*
1b9c12f4	365	* if EXT4_STATE_EXT_MIGRATE is cleared a block allocation
267e4db9 AK	366	* happened after we started the migrate. We need to
	367	* fail the migrate
	368	*/
19f5fb7a	369	if (!ext4_test_inode_state(inode, EXT4_STATE_EXT_MIGRATE)) {
267e4db9 AK	370	retval = -EAGAIN;
	371	up_write(&EXT4_I(inode)->i_data_sem);
	372	goto err_out;
	373	} else
19f5fb7a	374	ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
c14c6fd5 AK	375	/*
	376	* We have the extent map build with the tmp inode.
	377	* Now copy the i_data across
	378	*/
07a03824	379	ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS);
c14c6fd5 AK	380	memcpy(ei->i_data, tmp_ei->i_data, sizeof(ei->i_data));
	381
	382	/*
	383	* Update i_blocks with the new blocks that got
	384	* allocated while adding extents for extent index
	385	* blocks.
	386	*
	387	* While converting to extents we need not
	388	* update the orignal inode i_blocks for extent blocks
	389	* via quota APIs. The quota update happened via tmp_inode already.
	390	*/
	391	spin_lock(&inode->i_lock);
	392	inode->i_blocks += tmp_inode->i_blocks;
	393	spin_unlock(&inode->i_lock);
8009f9fb	394	up_write(&EXT4_I(inode)->i_data_sem);
c14c6fd5	395
8009f9fb AK	396	/*
	397	* We mark the inode dirty after, because we decrement the
	398	* i_blocks when freeing the indirect meta-data blocks
	399	*/
	400	retval = free_ind_block(handle, inode, i_data);
c14c6fd5	401	ext4_mark_inode_dirty(handle, inode);
8009f9fb	402
c14c6fd5 AK	403	err_out:
	404	return retval;
	405	}
	406
	407	static int free_ext_idx(handle_t handle, struct inode inode,
	408	struct ext4_extent_idx *ix)
	409	{
	410	int i, retval = 0;
	411	ext4_fsblk_t block;
	412	struct buffer_head *bh;
	413	struct ext4_extent_header *eh;
	414
bf89d16f	415	block = ext4_idx_pblock(ix);
c14c6fd5 AK	416	bh = sb_bread(inode->i_sb, block);
	417	if (!bh)
	418	return -EIO;
	419
	420	eh = (struct ext4_extent_header *)bh->b_data;
	421	if (eh->eh_depth != 0) {
	422	ix = EXT_FIRST_INDEX(eh);
	423	for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
	424	retval = free_ext_idx(handle, inode, ix);
	425	if (retval)
	426	break;
	427	}
	428	}
	429	put_bh(bh);
8009f9fb	430	extend_credit_for_blkdel(handle, inode);
e6362609 TT	431	ext4_free_blocks(handle, inode, 0, block, 1,
e6362609 TT	432	EXT4_FREE_BLOCKS_METADATA \| EXT4_FREE_BLOCKS_FORGET);
c14c6fd5 AK	433	return retval;
	434	}
	435
	436	/*
	437	* Free the extent meta data blocks only
	438	*/
	439	static int free_ext_block(handle_t handle, struct inode inode)
	440	{
	441	int i, retval = 0;
	442	struct ext4_inode_info *ei = EXT4_I(inode);
	443	struct ext4_extent_header eh = (struct ext4_extent_header )ei->i_data;
	444	struct ext4_extent_idx *ix;
	445	if (eh->eh_depth == 0)
	446	/*
	447	* No extra blocks allocated for extent meta data
	448	*/
	449	return 0;
	450	ix = EXT_FIRST_INDEX(eh);
	451	for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
	452	retval = free_ext_idx(handle, inode, ix);
	453	if (retval)
	454	return retval;
	455	}
	456	return retval;
	457
	458	}
	459
2a43a878	460	int ext4_ext_migrate(struct inode *inode)
c14c6fd5 AK	461	{
	462	handle_t *handle;
	463	int retval = 0, i;
	464	__le32 *i_data;
	465	ext4_lblk_t blk_count = 0;
	466	struct ext4_inode_info *ei;
	467	struct inode *tmp_inode = NULL;
	468	struct list_blocks_struct lb;
	469	unsigned long max_entries;
11013911	470	__u32 goal;
c14c6fd5	471
83982b6f TT	472	/*
	473	* If the filesystem does not support extents, or the inode
	474	* already is extent-based, error out.
	475	*/
	476	if (!EXT4_HAS_INCOMPAT_FEATURE(inode->i_sb,
	477	EXT4_FEATURE_INCOMPAT_EXTENTS) \|\|
12e9b892	478	(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
c14c6fd5 AK	479	return -EINVAL;
c14c6fd5 AK	480
b8356c46 VC	481	if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0)
	482	/*
	483	* don't migrate fast symlink
	484	*/
	485	return retval;
	486
c14c6fd5 AK	487	handle = ext4_journal_start(inode,
	488	EXT4_DATA_TRANS_BLOCKS(inode->i_sb) +
	489	EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
5aca07eb	490	EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)
c14c6fd5 AK	491	+ 1);
	492	if (IS_ERR(handle)) {
	493	retval = PTR_ERR(handle);
09054264	494	return retval;
c14c6fd5	495	}
11013911 AD	496	goal = (((inode->i_ino - 1) / EXT4_INODES_PER_GROUP(inode->i_sb)) *
11013911 AD	497	EXT4_INODES_PER_GROUP(inode->i_sb)) + 1;
f157a4aa	498	tmp_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
11013911	499	S_IFREG, 0, goal);
c14c6fd5 AK	500	if (IS_ERR(tmp_inode)) {
	501	retval = -ENOMEM;
	502	ext4_journal_stop(handle);
09054264	503	return retval;
c14c6fd5 AK	504	}
	505	i_size_write(tmp_inode, i_size_read(inode));
	506	/*
f39490bc DM	507	* Set the i_nlink to zero so it will be deleted later
f39490bc DM	508	* when we drop inode reference.
c14c6fd5	509	*/
f39490bc	510	tmp_inode->i_nlink = 0;
c14c6fd5 AK	511
	512	ext4_ext_tree_init(handle, tmp_inode);
	513	ext4_orphan_add(handle, tmp_inode);
	514	ext4_journal_stop(handle);
	515
c14c6fd5 AK	516	/*
	517	* start with one credit accounted for
	518	* superblock modification.
	519	*
	520	* For the tmp_inode we already have commited the
	521	* trascation that created the inode. Later as and
	522	* when we add extents we extent the journal
	523	*/
267e4db9	524	/*
1b9c12f4 TT	525	* Even though we take i_mutex we can still cause block
	526	* allocation via mmap write to holes. If we have allocated
	527	* new blocks we fail migrate. New block allocation will
	528	* clear EXT4_STATE_EXT_MIGRATE flag. The flag is updated
	529	* with i_data_sem held to prevent racing with block
	530	* allocation.
267e4db9 AK	531	*/
267e4db9 AK	532	down_read((&EXT4_I(inode)->i_data_sem));
19f5fb7a	533	ext4_set_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
267e4db9 AK	534	up_read((&EXT4_I(inode)->i_data_sem));
267e4db9 AK	535
c14c6fd5	536	handle = ext4_journal_start(inode, 1);
f39490bc DM	537	if (IS_ERR(handle)) {
	538	/*
	539	* It is impossible to update on-disk structures without
	540	* a handle, so just rollback in-core changes and live other
	541	* work to orphan_list_cleanup()
	542	*/
	543	ext4_orphan_del(NULL, tmp_inode);
	544	retval = PTR_ERR(handle);
	545	goto out;
	546	}
8009f9fb AK	547
	548	ei = EXT4_I(inode);
	549	i_data = ei->i_data;
	550	memset(&lb, 0, sizeof(lb));
	551
	552	/* 32 bit block address 4 bytes */
	553	max_entries = inode->i_sb->s_blocksize >> 2;
c14c6fd5 AK	554	for (i = 0; i < EXT4_NDIR_BLOCKS; i++, blk_count++) {
	555	if (i_data[i]) {
	556	retval = update_extent_range(handle, tmp_inode,
	557	le32_to_cpu(i_data[i]),
	558	blk_count, &lb);
	559	if (retval)
	560	goto err_out;
	561	}
	562	}
	563	if (i_data[EXT4_IND_BLOCK]) {
	564	retval = update_ind_extent_range(handle, tmp_inode,
	565	le32_to_cpu(i_data[EXT4_IND_BLOCK]),
	566	&blk_count, &lb);
	567	if (retval)
	568	goto err_out;
	569	} else
	570	blk_count += max_entries;
	571	if (i_data[EXT4_DIND_BLOCK]) {
	572	retval = update_dind_extent_range(handle, tmp_inode,
	573	le32_to_cpu(i_data[EXT4_DIND_BLOCK]),
	574	&blk_count, &lb);
	575	if (retval)
	576	goto err_out;
	577	} else
	578	blk_count += max_entries * max_entries;
	579	if (i_data[EXT4_TIND_BLOCK]) {
	580	retval = update_tind_extent_range(handle, tmp_inode,
	581	le32_to_cpu(i_data[EXT4_TIND_BLOCK]),
	582	&blk_count, &lb);
	583	if (retval)
	584	goto err_out;
	585	}
	586	/*
	587	* Build the last extent
	588	*/
	589	retval = finish_range(handle, tmp_inode, &lb);
	590	err_out:
c14c6fd5 AK	591	if (retval)
	592	/*
	593	* Failure case delete the extent information with the
	594	* tmp_inode
	595	*/
	596	free_ext_block(handle, tmp_inode);
267e4db9 AK	597	else {
	598	retval = ext4_ext_swap_inode_data(handle, inode, tmp_inode);
	599	if (retval)
	600	/*
	601	* if we fail to swap inode data free the extent
	602	* details of the tmp inode
	603	*/
	604	free_ext_block(handle, tmp_inode);
	605	}
8009f9fb AK	606
	607	/* We mark the tmp_inode dirty via ext4_ext_tree_init. */
	608	if (ext4_journal_extend(handle, 1) != 0)
	609	ext4_journal_restart(handle, 1);
c14c6fd5 AK	610
	611	/*
	612	* Mark the tmp_inode as of size zero
	613	*/
	614	i_size_write(tmp_inode, 0);
	615
	616	/*
	617	* set the i_blocks count to zero
	618	* so that the ext4_delete_inode does the
	619	* right job
	620	*
	621	* We don't need to take the i_lock because
	622	* the inode is not visible to user space.
	623	*/
	624	tmp_inode->i_blocks = 0;
	625
	626	/* Reset the extent details */
	627	ext4_ext_tree_init(handle, tmp_inode);
c14c6fd5	628	ext4_journal_stop(handle);
f39490bc	629	out:
a8526e84	630	unlock_new_inode(tmp_inode);
09054264	631	iput(tmp_inode);
c14c6fd5 AK	632
	633	return retval;
	634	}