[linux.git] / fs / ext4 / migrate.c

/*
 * Copyright IBM Corporation, 2007
 * Author Aneesh Kumar K.V <[email protected]>
 *
 * 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 "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_I(inode)->i_state & EXT4_STATE_EXT_MIGRATE)) {
		retval = -EAGAIN;
		up_write(&EXT4_I(inode)->i_data_sem);
		goto err_out;
	} else
		EXT4_I(inode)->i_state &= ~EXT4_STATE_EXT_MIGRATE;
	/*
	 * We have the extent map build with the tmp inode.
	 * Now copy the i_data across
	 */
	ei->i_flags |= EXT4_EXTENTS_FL;
	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 = 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_I(inode)->i_flags & EXT4_EXTENTS_FL))
		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));
	/*
	 * We don't want the inode to be reclaimed
	 * if we got interrupted in between. We have
	 * this tmp inode carrying reference to the
	 * data blocks of the original file. We set
	 * the i_nlink to zero at the last stage after
	 * switching the original file to extent format
	 */
	tmp_inode->i_nlink = 1;

	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_I(inode)->i_state |= EXT4_STATE_EXT_MIGRATE;
	up_read((&EXT4_I(inode)->i_data_sem));

	handle = ext4_journal_start(inode, 1);

	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);

	/*
	 * Set the i_nlink to zero so that
	 * generic_drop_inode really deletes the
	 * inode
	 */
	tmp_inode->i_nlink = 0;

	ext4_journal_stop(handle);
	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 <[email protected]>
	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>
3dcf5451 CH	16	#include "ext4_jbd2.h"
3dcf5451 CH	17	#include "ext4_extents.h"
c14c6fd5 AK	18
	19	/*
	20	* The contiguous blocks details which can be
	21	* represented by a single extent
	22	*/
	23	struct list_blocks_struct {
	24	ext4_lblk_t first_block, last_block;
	25	ext4_fsblk_t first_pblock, last_pblock;
	26	};
	27
	28	static int finish_range(handle_t handle, struct inode inode,
	29	struct list_blocks_struct *lb)
	30
	31	{
	32	int retval = 0, needed;
	33	struct ext4_extent newext;
	34	struct ext4_ext_path *path;
	35	if (lb->first_pblock == 0)
	36	return 0;
	37
	38	/* Add the extent to temp inode*/
	39	newext.ee_block = cpu_to_le32(lb->first_block);
	40	newext.ee_len = cpu_to_le16(lb->last_block - lb->first_block + 1);
	41	ext4_ext_store_pblock(&newext, lb->first_pblock);
	42	path = ext4_ext_find_extent(inode, lb->first_block, NULL);
	43
	44	if (IS_ERR(path)) {
	45	retval = PTR_ERR(path);
b35905c1	46	path = NULL;
c14c6fd5 AK	47	goto err_out;
	48	}
	49
	50	/*
	51	* Calculate the credit needed to inserting this extent
	52	* Since we are doing this in loop we may accumalate extra
	53	* credit. But below we try to not accumalate too much
	54	* of them by restarting the journal.
	55	*/
ee12b630 MC	56	needed = ext4_ext_calc_credits_for_single_extent(inode,
ee12b630 MC	57	lb->last_block - lb->first_block + 1, path);
c14c6fd5 AK	58
	59	/*
	60	* Make sure the credit we accumalated is not really high
	61	*/
0390131b FM	62	if (needed && ext4_handle_has_enough_credits(handle,
0390131b FM	63	EXT4_RESERVE_TRANS_BLOCKS)) {
c14c6fd5 AK	64	retval = ext4_journal_restart(handle, needed);
	65	if (retval)
	66	goto err_out;
8009f9fb	67	} else if (needed) {
c14c6fd5	68	retval = ext4_journal_extend(handle, needed);
8009f9fb	69	if (retval) {
c14c6fd5 AK	70	/*
	71	* IF not able to extend the journal restart the journal
	72	*/
	73	retval = ext4_journal_restart(handle, needed);
	74	if (retval)
	75	goto err_out;
	76	}
	77	}
0031462b	78	retval = ext4_ext_insert_extent(handle, inode, path, &newext, 0);
c14c6fd5	79	err_out:
b35905c1 AK	80	if (path) {
	81	ext4_ext_drop_refs(path);
	82	kfree(path);
	83	}
c14c6fd5 AK	84	lb->first_pblock = 0;
	85	return retval;
	86	}
	87
	88	static int update_extent_range(handle_t handle, struct inode inode,
	89	ext4_fsblk_t pblock, ext4_lblk_t blk_num,
	90	struct list_blocks_struct *lb)
	91	{
	92	int retval;
	93	/*
	94	* See if we can add on to the existing range (if it exists)
	95	*/
	96	if (lb->first_pblock &&
	97	(lb->last_pblock+1 == pblock) &&
	98	(lb->last_block+1 == blk_num)) {
	99	lb->last_pblock = pblock;
	100	lb->last_block = blk_num;
	101	return 0;
	102	}
	103	/*
	104	* Start a new range.
	105	*/
	106	retval = finish_range(handle, inode, lb);
	107	lb->first_pblock = lb->last_pblock = pblock;
	108	lb->first_block = lb->last_block = blk_num;
	109
	110	return retval;
	111	}
	112
	113	static int update_ind_extent_range(handle_t handle, struct inode inode,
	114	ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
	115	struct list_blocks_struct *lb)
	116	{
	117	struct buffer_head *bh;
	118	__le32 *i_data;
	119	int i, retval = 0;
	120	ext4_lblk_t blk_count = *blk_nump;
	121	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
	122
	123	if (!pblock) {
	124	/* Only update the file block number */
	125	*blk_nump += max_entries;
	126	return 0;
	127	}
	128
	129	bh = sb_bread(inode->i_sb, pblock);
	130	if (!bh)
	131	return -EIO;
	132
	133	i_data = (__le32 *)bh->b_data;
	134	for (i = 0; i < max_entries; i++, blk_count++) {
	135	if (i_data[i]) {
	136	retval = update_extent_range(handle, inode,
	137	le32_to_cpu(i_data[i]),
	138	blk_count, lb);
	139	if (retval)
	140	break;
	141	}
	142	}
	143
	144	/* Update the file block number */
	145	*blk_nump = blk_count;
	146	put_bh(bh);
	147	return retval;
148
149	}
150
151	static int update_dind_extent_range(handle_t handle, struct inode inode,
152	ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
153	struct list_blocks_struct *lb)
154	{
155	struct buffer_head *bh;
156	__le32 *i_data;
157	int i, retval = 0;
158	ext4_lblk_t blk_count = *blk_nump;
159	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
160
161	if (!pblock) {
162	/* Only update the file block number */
163	blk_nump += max_entries max_entries;
164	return 0;
165	}
166	bh = sb_bread(inode->i_sb, pblock);
167	if (!bh)
168	return -EIO;
169
170	i_data = (__le32 *)bh->b_data;
171	for (i = 0; i < max_entries; i++) {
172	if (i_data[i]) {
173	retval = update_ind_extent_range(handle, inode,
174	le32_to_cpu(i_data[i]),
175	&blk_count, lb);
176	if (retval)
177	break;
178	} else {
179	/* Only update the file block number */
180	blk_count += max_entries;
181	}
182	}
183
184	/* Update the file block number */
185	*blk_nump = blk_count;
186	put_bh(bh);
187	return retval;
188
189	}
190
191	static int update_tind_extent_range(handle_t handle, struct inode inode,
192	ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
193	struct list_blocks_struct *lb)
194	{
195	struct buffer_head *bh;
196	__le32 *i_data;
197	int i, retval = 0;
198	ext4_lblk_t blk_count = *blk_nump;
199	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
200
201	if (!pblock) {
202	/* Only update the file block number */
203	blk_nump += max_entries max_entries * max_entries;
204	return 0;
205	}
206	bh = sb_bread(inode->i_sb, pblock);
207	if (!bh)
208	return -EIO;
209
210	i_data = (__le32 *)bh->b_data;
211	for (i = 0; i < max_entries; i++) {
212	if (i_data[i]) {
213	retval = update_dind_extent_range(handle, inode,
214	le32_to_cpu(i_data[i]),
215	&blk_count, lb);
216	if (retval)
217	break;
218	} else
219	/* Only update the file block number */
220	blk_count += max_entries * max_entries;
221	}
222	/* Update the file block number */
223	*blk_nump = blk_count;
224	put_bh(bh);
225	return retval;
226
227	}
228
8009f9fb AK	229	static int extend_credit_for_blkdel(handle_t handle, struct inode inode)
	230	{
	231	int retval = 0, needed;
	232
0390131b	233	if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
8009f9fb AK	234	return 0;
	235	/*
	236	* We are freeing a blocks. During this we touch
	237	* superblock, group descriptor and block bitmap.
	238	* So allocate a credit of 3. We may update
	239	* quota (user and group).
	240	*/
5aca07eb	241	needed = 3 + EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
8009f9fb AK	242
	243	if (ext4_journal_extend(handle, needed) != 0)
	244	retval = ext4_journal_restart(handle, needed);
	245
	246	return retval;
	247	}
	248
c14c6fd5 AK	249	static int free_dind_blocks(handle_t *handle,
	250	struct inode *inode, __le32 i_data)
	251	{
	252	int i;
	253	__le32 *tmp_idata;
	254	struct buffer_head *bh;
	255	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
	256
	257	bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
	258	if (!bh)
	259	return -EIO;
	260
	261	tmp_idata = (__le32 *)bh->b_data;
	262	for (i = 0; i < max_entries; i++) {
8009f9fb AK	263	if (tmp_idata[i]) {
8009f9fb AK	264	extend_credit_for_blkdel(handle, inode);
e6362609 TT	265	ext4_free_blocks(handle, inode, 0,
	266	le32_to_cpu(tmp_idata[i]), 1,
	267	EXT4_FREE_BLOCKS_METADATA \|
	268	EXT4_FREE_BLOCKS_FORGET);
8009f9fb	269	}
c14c6fd5 AK	270	}
c14c6fd5 AK	271	put_bh(bh);
8009f9fb	272	extend_credit_for_blkdel(handle, inode);
e6362609 TT	273	ext4_free_blocks(handle, inode, 0, le32_to_cpu(i_data), 1,
	274	EXT4_FREE_BLOCKS_METADATA \|
	275	EXT4_FREE_BLOCKS_FORGET);
c14c6fd5 AK	276	return 0;
	277	}
	278
	279	static int free_tind_blocks(handle_t *handle,
	280	struct inode *inode, __le32 i_data)
	281	{
	282	int i, retval = 0;
	283	__le32 *tmp_idata;
	284	struct buffer_head *bh;
	285	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
	286
	287	bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
	288	if (!bh)
	289	return -EIO;
	290
	291	tmp_idata = (__le32 *)bh->b_data;
	292	for (i = 0; i < max_entries; i++) {
	293	if (tmp_idata[i]) {
	294	retval = free_dind_blocks(handle,
	295	inode, tmp_idata[i]);
	296	if (retval) {
	297	put_bh(bh);
	298	return retval;
	299	}
	300	}
	301	}
	302	put_bh(bh);
8009f9fb	303	extend_credit_for_blkdel(handle, inode);
e6362609 TT	304	ext4_free_blocks(handle, inode, 0, le32_to_cpu(i_data), 1,
	305	EXT4_FREE_BLOCKS_METADATA \|
	306	EXT4_FREE_BLOCKS_FORGET);
c14c6fd5 AK	307	return 0;
	308	}
	309
8009f9fb	310	static int free_ind_block(handle_t handle, struct inode inode, __le32 *i_data)
c14c6fd5 AK	311	{
c14c6fd5 AK	312	int retval;
c14c6fd5	313
8009f9fb AK	314	/* ei->i_data[EXT4_IND_BLOCK] */
	315	if (i_data[0]) {
	316	extend_credit_for_blkdel(handle, inode);
e6362609 TT	317	ext4_free_blocks(handle, inode, 0,
	318	le32_to_cpu(i_data[0]), 1,
	319	EXT4_FREE_BLOCKS_METADATA \|
	320	EXT4_FREE_BLOCKS_FORGET);
8009f9fb	321	}
c14c6fd5	322
8009f9fb AK	323	/* ei->i_data[EXT4_DIND_BLOCK] */
	324	if (i_data[1]) {
	325	retval = free_dind_blocks(handle, inode, i_data[1]);
c14c6fd5 AK	326	if (retval)
	327	return retval;
	328	}
	329
8009f9fb AK	330	/* ei->i_data[EXT4_TIND_BLOCK] */
	331	if (i_data[2]) {
	332	retval = free_tind_blocks(handle, inode, i_data[2]);
c14c6fd5 AK	333	if (retval)
	334	return retval;
	335	}
	336	return 0;
	337	}
	338
	339	static int ext4_ext_swap_inode_data(handle_t handle, struct inode inode,
267e4db9	340	struct inode *tmp_inode)
c14c6fd5	341	{
8009f9fb AK	342	int retval;
8009f9fb AK	343	__le32 i_data[3];
c14c6fd5 AK	344	struct ext4_inode_info *ei = EXT4_I(inode);
	345	struct ext4_inode_info *tmp_ei = EXT4_I(tmp_inode);
	346
c14c6fd5 AK	347	/*
	348	* One credit accounted for writing the
	349	* i_data field of the original inode
	350	*/
	351	retval = ext4_journal_extend(handle, 1);
267e4db9	352	if (retval) {
c14c6fd5 AK	353	retval = ext4_journal_restart(handle, 1);
	354	if (retval)
	355	goto err_out;
	356	}
	357
8009f9fb AK	358	i_data[0] = ei->i_data[EXT4_IND_BLOCK];
	359	i_data[1] = ei->i_data[EXT4_DIND_BLOCK];
	360	i_data[2] = ei->i_data[EXT4_TIND_BLOCK];
	361
	362	down_write(&EXT4_I(inode)->i_data_sem);
267e4db9	363	/*
1b9c12f4	364	* if EXT4_STATE_EXT_MIGRATE is cleared a block allocation
267e4db9 AK	365	* happened after we started the migrate. We need to
	366	* fail the migrate
	367	*/
1b9c12f4	368	if (!(EXT4_I(inode)->i_state & EXT4_STATE_EXT_MIGRATE)) {
267e4db9 AK	369	retval = -EAGAIN;
	370	up_write(&EXT4_I(inode)->i_data_sem);
	371	goto err_out;
	372	} else
1b9c12f4	373	EXT4_I(inode)->i_state &= ~EXT4_STATE_EXT_MIGRATE;
c14c6fd5 AK	374	/*
	375	* We have the extent map build with the tmp inode.
	376	* Now copy the i_data across
	377	*/
	378	ei->i_flags \|= EXT4_EXTENTS_FL;
	379	memcpy(ei->i_data, tmp_ei->i_data, sizeof(ei->i_data));
	380
	381	/*
	382	* Update i_blocks with the new blocks that got
	383	* allocated while adding extents for extent index
	384	* blocks.
	385	*
	386	* While converting to extents we need not
	387	* update the orignal inode i_blocks for extent blocks
	388	* via quota APIs. The quota update happened via tmp_inode already.
	389	*/
	390	spin_lock(&inode->i_lock);
	391	inode->i_blocks += tmp_inode->i_blocks;
	392	spin_unlock(&inode->i_lock);
8009f9fb	393	up_write(&EXT4_I(inode)->i_data_sem);
c14c6fd5	394
8009f9fb AK	395	/*
	396	* We mark the inode dirty after, because we decrement the
	397	* i_blocks when freeing the indirect meta-data blocks
	398	*/
	399	retval = free_ind_block(handle, inode, i_data);
c14c6fd5	400	ext4_mark_inode_dirty(handle, inode);
8009f9fb	401
c14c6fd5 AK	402	err_out:
	403	return retval;
	404	}
	405
	406	static int free_ext_idx(handle_t handle, struct inode inode,
	407	struct ext4_extent_idx *ix)
	408	{
	409	int i, retval = 0;
	410	ext4_fsblk_t block;
	411	struct buffer_head *bh;
	412	struct ext4_extent_header *eh;
	413
	414	block = idx_pblock(ix);
	415	bh = sb_bread(inode->i_sb, block);
	416	if (!bh)
	417	return -EIO;
	418
	419	eh = (struct ext4_extent_header *)bh->b_data;
	420	if (eh->eh_depth != 0) {
	421	ix = EXT_FIRST_INDEX(eh);
	422	for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
	423	retval = free_ext_idx(handle, inode, ix);
	424	if (retval)
	425	break;
	426	}
	427	}
	428	put_bh(bh);
8009f9fb	429	extend_credit_for_blkdel(handle, inode);
e6362609 TT	430	ext4_free_blocks(handle, inode, 0, block, 1,
e6362609 TT	431	EXT4_FREE_BLOCKS_METADATA \| EXT4_FREE_BLOCKS_FORGET);
c14c6fd5 AK	432	return retval;
	433	}
	434
	435	/*
	436	* Free the extent meta data blocks only
	437	*/
	438	static int free_ext_block(handle_t handle, struct inode inode)
	439	{
	440	int i, retval = 0;
	441	struct ext4_inode_info *ei = EXT4_I(inode);
	442	struct ext4_extent_header eh = (struct ext4_extent_header )ei->i_data;
	443	struct ext4_extent_idx *ix;
	444	if (eh->eh_depth == 0)
	445	/*
	446	* No extra blocks allocated for extent meta data
	447	*/
	448	return 0;
	449	ix = EXT_FIRST_INDEX(eh);
	450	for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
	451	retval = free_ext_idx(handle, inode, ix);
	452	if (retval)
	453	return retval;
	454	}
	455	return retval;
	456
	457	}
	458
2a43a878	459	int ext4_ext_migrate(struct inode *inode)
c14c6fd5 AK	460	{
	461	handle_t *handle;
	462	int retval = 0, i;
	463	__le32 *i_data;
	464	ext4_lblk_t blk_count = 0;
	465	struct ext4_inode_info *ei;
	466	struct inode *tmp_inode = NULL;
	467	struct list_blocks_struct lb;
	468	unsigned long max_entries;
11013911	469	__u32 goal;
c14c6fd5	470
83982b6f TT	471	/*
	472	* If the filesystem does not support extents, or the inode
	473	* already is extent-based, error out.
	474	*/
	475	if (!EXT4_HAS_INCOMPAT_FEATURE(inode->i_sb,
	476	EXT4_FEATURE_INCOMPAT_EXTENTS) \|\|
	477	(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
c14c6fd5 AK	478	return -EINVAL;
c14c6fd5 AK	479
b8356c46 VC	480	if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0)
	481	/*
	482	* don't migrate fast symlink
	483	*/
	484	return retval;
	485
c14c6fd5 AK	486	handle = ext4_journal_start(inode,
	487	EXT4_DATA_TRANS_BLOCKS(inode->i_sb) +
	488	EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
5aca07eb	489	EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)
c14c6fd5 AK	490	+ 1);
	491	if (IS_ERR(handle)) {
	492	retval = PTR_ERR(handle);
09054264	493	return retval;
c14c6fd5	494	}
11013911 AD	495	goal = (((inode->i_ino - 1) / EXT4_INODES_PER_GROUP(inode->i_sb)) *
11013911 AD	496	EXT4_INODES_PER_GROUP(inode->i_sb)) + 1;
f157a4aa	497	tmp_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
11013911	498	S_IFREG, 0, goal);
c14c6fd5 AK	499	if (IS_ERR(tmp_inode)) {
	500	retval = -ENOMEM;
	501	ext4_journal_stop(handle);
09054264	502	return retval;
c14c6fd5 AK	503	}
	504	i_size_write(tmp_inode, i_size_read(inode));
	505	/*
	506	* We don't want the inode to be reclaimed
	507	* if we got interrupted in between. We have
	508	* this tmp inode carrying reference to the
	509	* data blocks of the original file. We set
	510	* the i_nlink to zero at the last stage after
	511	* switching the original file to extent format
	512	*/
	513	tmp_inode->i_nlink = 1;
	514
	515	ext4_ext_tree_init(handle, tmp_inode);
	516	ext4_orphan_add(handle, tmp_inode);
	517	ext4_journal_stop(handle);
	518
c14c6fd5 AK	519	/*
	520	* start with one credit accounted for
	521	* superblock modification.
	522	*
	523	* For the tmp_inode we already have commited the
	524	* trascation that created the inode. Later as and
	525	* when we add extents we extent the journal
	526	*/
267e4db9	527	/*
1b9c12f4 TT	528	* Even though we take i_mutex we can still cause block
	529	* allocation via mmap write to holes. If we have allocated
	530	* new blocks we fail migrate. New block allocation will
	531	* clear EXT4_STATE_EXT_MIGRATE flag. The flag is updated
	532	* with i_data_sem held to prevent racing with block
	533	* allocation.
267e4db9 AK	534	*/
267e4db9 AK	535	down_read((&EXT4_I(inode)->i_data_sem));
1b9c12f4	536	EXT4_I(inode)->i_state \|= EXT4_STATE_EXT_MIGRATE;
267e4db9 AK	537	up_read((&EXT4_I(inode)->i_data_sem));
267e4db9 AK	538
c14c6fd5	539	handle = ext4_journal_start(inode, 1);
8009f9fb AK	540
	541	ei = EXT4_I(inode);
	542	i_data = ei->i_data;
	543	memset(&lb, 0, sizeof(lb));
	544
	545	/* 32 bit block address 4 bytes */
	546	max_entries = inode->i_sb->s_blocksize >> 2;
c14c6fd5 AK	547	for (i = 0; i < EXT4_NDIR_BLOCKS; i++, blk_count++) {
	548	if (i_data[i]) {
	549	retval = update_extent_range(handle, tmp_inode,
	550	le32_to_cpu(i_data[i]),
	551	blk_count, &lb);
	552	if (retval)
	553	goto err_out;
	554	}
	555	}
	556	if (i_data[EXT4_IND_BLOCK]) {
	557	retval = update_ind_extent_range(handle, tmp_inode,
	558	le32_to_cpu(i_data[EXT4_IND_BLOCK]),
	559	&blk_count, &lb);
	560	if (retval)
	561	goto err_out;
	562	} else
	563	blk_count += max_entries;
	564	if (i_data[EXT4_DIND_BLOCK]) {
	565	retval = update_dind_extent_range(handle, tmp_inode,
	566	le32_to_cpu(i_data[EXT4_DIND_BLOCK]),
	567	&blk_count, &lb);
	568	if (retval)
	569	goto err_out;
	570	} else
	571	blk_count += max_entries * max_entries;
	572	if (i_data[EXT4_TIND_BLOCK]) {
	573	retval = update_tind_extent_range(handle, tmp_inode,
	574	le32_to_cpu(i_data[EXT4_TIND_BLOCK]),
	575	&blk_count, &lb);
	576	if (retval)
	577	goto err_out;
	578	}
	579	/*
	580	* Build the last extent
	581	*/
	582	retval = finish_range(handle, tmp_inode, &lb);
	583	err_out:
c14c6fd5 AK	584	if (retval)
	585	/*
	586	* Failure case delete the extent information with the
	587	* tmp_inode
	588	*/
	589	free_ext_block(handle, tmp_inode);
267e4db9 AK	590	else {
	591	retval = ext4_ext_swap_inode_data(handle, inode, tmp_inode);
	592	if (retval)
	593	/*
	594	* if we fail to swap inode data free the extent
	595	* details of the tmp inode
	596	*/
	597	free_ext_block(handle, tmp_inode);
	598	}
8009f9fb AK	599
	600	/* We mark the tmp_inode dirty via ext4_ext_tree_init. */
	601	if (ext4_journal_extend(handle, 1) != 0)
	602	ext4_journal_restart(handle, 1);
c14c6fd5 AK	603
	604	/*
	605	* Mark the tmp_inode as of size zero
	606	*/
	607	i_size_write(tmp_inode, 0);
	608
	609	/*
	610	* set the i_blocks count to zero
	611	* so that the ext4_delete_inode does the
	612	* right job
	613	*
	614	* We don't need to take the i_lock because
	615	* the inode is not visible to user space.
	616	*/
	617	tmp_inode->i_blocks = 0;
	618
	619	/* Reset the extent details */
	620	ext4_ext_tree_init(handle, tmp_inode);
	621
	622	/*
	623	* Set the i_nlink to zero so that
	624	* generic_drop_inode really deletes the
	625	* inode
	626	*/
	627	tmp_inode->i_nlink = 0;
	628
	629	ext4_journal_stop(handle);
a8526e84	630	unlock_new_inode(tmp_inode);
09054264	631	iput(tmp_inode);
c14c6fd5 AK	632
	633	return retval;
	634	}