[thirdparty/e2fsprogs.git] / lib / ext2fs / bmap.c

/*
 * bmap.c --- logical to physical block mapping
 *
 * Copyright (C) 1997 Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU Library
 * General Public License, version 2.
 * %End-Header%
 */

#include "config.h"
#include <stdio.h>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <errno.h>

#include "ext2_fs.h"
#include "ext2fsP.h"

#if defined(__GNUC__) && !defined(NO_INLINE_FUNCS)
#define _BMAP_INLINE_	__inline__
#else
#define _BMAP_INLINE_
#endif

extern errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino,
			     struct ext2_inode *inode,
			     char *block_buf, int bmap_flags,
			     blk_t block, blk_t *phys_blk);

#define inode_bmap(inode, nr) ((inode)->i_block[(nr)])

static _BMAP_INLINE_ errcode_t block_ind_bmap(ext2_filsys fs, int flags,
					      blk_t ind, char *block_buf,
					      int *blocks_alloc,
					      blk_t nr, blk_t *ret_blk)
{
	errcode_t	retval;
	blk_t		b;

	if (!ind) {
		if (flags & BMAP_SET)
			return EXT2_ET_SET_BMAP_NO_IND;
		*ret_blk = 0;
		return 0;
	}
	retval = io_channel_read_blk(fs->io, ind, 1, block_buf);
	if (retval)
		return retval;

	if (flags & BMAP_SET) {
		b = *ret_blk;
#ifdef WORDS_BIGENDIAN
		b = ext2fs_swab32(b);
#endif
		((blk_t *) block_buf)[nr] = b;
		return io_channel_write_blk(fs->io, ind, 1, block_buf);
	}

	b = ((blk_t *) block_buf)[nr];

#ifdef WORDS_BIGENDIAN
	b = ext2fs_swab32(b);
#endif

	if (!b && (flags & BMAP_ALLOC)) {
		b = nr ? ext2fs_le32_to_cpu(((blk_t *)block_buf)[nr - 1]) : ind;
		retval = ext2fs_alloc_block(fs, b,
					    block_buf + fs->blocksize, &b);
		if (retval)
			return retval;

#ifdef WORDS_BIGENDIAN
		((blk_t *) block_buf)[nr] = ext2fs_swab32(b);
#else
		((blk_t *) block_buf)[nr] = b;
#endif

		retval = io_channel_write_blk(fs->io, ind, 1, block_buf);
		if (retval)
			return retval;

		(*blocks_alloc)++;
	}

	*ret_blk = b;
	return 0;
}

static _BMAP_INLINE_ errcode_t block_dind_bmap(ext2_filsys fs, int flags,
					       blk_t dind, char *block_buf,
					       int *blocks_alloc,
					       blk_t nr, blk_t *ret_blk)
{
	blk_t		b = 0;
	errcode_t	retval;
	blk_t		addr_per_block;

	addr_per_block = (blk_t) fs->blocksize >> 2;

	retval = block_ind_bmap(fs, flags & ~BMAP_SET, dind, block_buf,
				blocks_alloc, nr / addr_per_block, &b);
	if (retval)
		return retval;
	retval = block_ind_bmap(fs, flags, b, block_buf, blocks_alloc,
				nr % addr_per_block, ret_blk);
	return retval;
}

static _BMAP_INLINE_ errcode_t block_tind_bmap(ext2_filsys fs, int flags,
					       blk_t tind, char *block_buf,
					       int *blocks_alloc,
					       blk_t nr, blk_t *ret_blk)
{
	blk_t		b = 0;
	errcode_t	retval;
	blk_t		addr_per_block;

	addr_per_block = (blk_t) fs->blocksize >> 2;

	retval = block_dind_bmap(fs, flags & ~BMAP_SET, tind, block_buf,
				 blocks_alloc, nr / addr_per_block, &b);
	if (retval)
		return retval;
	retval = block_ind_bmap(fs, flags, b, block_buf, blocks_alloc,
				nr % addr_per_block, ret_blk);
	return retval;
}

static errcode_t extent_bmap(ext2_filsys fs, ext2_ino_t ino,
			     struct ext2_inode *inode,
			     ext2_extent_handle_t handle,
			     char *block_buf, int bmap_flags, blk64_t block,
			     int *ret_flags, int *blocks_alloc,
			     blk64_t *phys_blk);

static errcode_t implied_cluster_alloc(ext2_filsys fs, ext2_ino_t ino,
				       struct ext2_inode *inode,
				       ext2_extent_handle_t handle,
				       blk64_t lblk, blk64_t *phys_blk)
{
	blk64_t	base_block, pblock = 0;
	int i;

	if (!ext2fs_has_feature_bigalloc(fs->super))
		return 0;

	base_block = lblk & ~EXT2FS_CLUSTER_MASK(fs);
	/*
	 * Except for the logical block (lblk) that was passed in, search all
	 * blocks in this logical cluster for a mapping to a physical cluster.
	 * If any such map exists, calculate the physical block that maps to
	 * the logical block and return that.
	 *
	 * The old code wouldn't even look if (block % cluster_ratio) == 0;
	 * this is incorrect if we're allocating blocks in reverse order.
	 */
	for (i = 0; i < EXT2FS_CLUSTER_RATIO(fs); i++) {
		if (base_block + i == lblk)
			continue;
		extent_bmap(fs, ino, inode, handle, 0, 0,
			    base_block + i, 0, 0, &pblock);
		if (pblock)
			break;
	}
	if (pblock == 0)
		return 0;
	*phys_blk = pblock - i + (lblk - base_block);
	return 0;
}

/* Try to map a logical block to an already-allocated physical cluster. */
errcode_t ext2fs_map_cluster_block(ext2_filsys fs, ext2_ino_t ino,
				   struct ext2_inode *inode, blk64_t lblk,
				   blk64_t *pblk)
{
	ext2_extent_handle_t handle;
	errcode_t retval;

	/* Need bigalloc and extents to be enabled */
	*pblk = 0;
	if (!ext2fs_has_feature_bigalloc(fs->super) ||
	    !(inode->i_flags & EXT4_EXTENTS_FL))
		return 0;

	retval = ext2fs_extent_open2(fs, ino, inode, &handle);
	if (retval)
		goto out;

	retval = implied_cluster_alloc(fs, ino, inode, handle, lblk, pblk);
	if (retval)
		goto out2;

out2:
	ext2fs_extent_free(handle);
out:
	return retval;
}

static errcode_t extent_bmap(ext2_filsys fs, ext2_ino_t ino,
			     struct ext2_inode *inode,
			     ext2_extent_handle_t handle,
			     char *block_buf, int bmap_flags, blk64_t block,
			     int *ret_flags, int *blocks_alloc,
			     blk64_t *phys_blk)
{
	struct blk_alloc_ctx	alloc_ctx;
	struct ext2fs_extent	extent;
	unsigned int		offset;
	errcode_t		retval = 0;
	blk64_t			blk64 = 0;
	int			alloc = 0;
	int			set_flags;

	set_flags = bmap_flags & BMAP_UNINIT ? EXT2_EXTENT_SET_BMAP_UNINIT : 0;

	if (bmap_flags & BMAP_SET) {
		retval = ext2fs_extent_set_bmap(handle, block,
						*phys_blk, set_flags);
		return retval;
	}
	retval = ext2fs_extent_goto(handle, block);
	if (retval) {
		/* If the extent is not found, return phys_blk = 0 */
		if (retval == EXT2_ET_EXTENT_NOT_FOUND) {
			extent.e_lblk = block;
			goto got_block;
		}
		return retval;
	}
	retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
	if (retval)
		return retval;
	offset = block - extent.e_lblk;
	if (block >= extent.e_lblk && (offset <= extent.e_len)) {
		*phys_blk = extent.e_pblk + offset;
		if (ret_flags && extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT)
			*ret_flags |= BMAP_RET_UNINIT;
	}
got_block:
	if ((*phys_blk == 0) && (bmap_flags & BMAP_ALLOC)) {
		implied_cluster_alloc(fs, ino, inode, handle, block, &blk64);
		if (blk64)
			goto set_extent;
		retval = extent_bmap(fs, ino, inode, handle, block_buf,
				     0, block-1, 0, blocks_alloc, &blk64);
		if (retval)
			blk64 = ext2fs_find_inode_goal(fs, ino, inode, block);
		alloc_ctx.ino = ino;
		alloc_ctx.inode = inode;
		alloc_ctx.lblk = extent.e_lblk;
		alloc_ctx.flags = BLOCK_ALLOC_DATA;
		retval = ext2fs_alloc_block3(fs, blk64, block_buf, &blk64,
					     &alloc_ctx);
		if (retval)
			return retval;
		blk64 &= ~EXT2FS_CLUSTER_MASK(fs);
		blk64 += EXT2FS_CLUSTER_MASK(fs) & block;
		alloc++;
	set_extent:
		retval = ext2fs_extent_set_bmap(handle, block,
						blk64, set_flags);
		if (retval) {
			ext2fs_block_alloc_stats2(fs, blk64, -1);
			return retval;
		}
		/* Update inode after setting extent */
		retval = ext2fs_read_inode(fs, ino, inode);
		if (retval)
			return retval;
		*blocks_alloc += alloc;
		*phys_blk = blk64;
	}
	return 0;
}

int ext2fs_file_block_offset_too_big(ext2_filsys fs,
				     struct ext2_inode *inode,
				     blk64_t offset)
{
	blk64_t addr_per_block, max_map_block;

	/* Kernel seems to cut us off at 4294967294 blocks */
	if (offset >= (1ULL << 32) - 1)
		return 1;

	if (inode->i_flags & EXT4_EXTENTS_FL)
		return 0;

	addr_per_block = fs->blocksize >> 2;
	max_map_block = addr_per_block;
	max_map_block += addr_per_block * addr_per_block;
	max_map_block += addr_per_block * addr_per_block * addr_per_block;
	max_map_block += 12;

	return offset >= max_map_block;
}

errcode_t ext2fs_bmap2(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode,
		       char *block_buf, int bmap_flags, blk64_t block,
		       int *ret_flags, blk64_t *phys_blk)
{
	struct ext2_inode inode_buf;
	ext2_extent_handle_t handle = 0;
	blk_t addr_per_block;
	blk_t	b, blk32;
	blk64_t b64;
	char	*buf = 0;
	errcode_t	retval = 0;
	int		blocks_alloc = 0, inode_dirty = 0;
	struct blk_alloc_ctx alloc_ctx = {
		.ino	= ino,
		.inode	= inode,
		.lblk	= 0,
		.flags	= BLOCK_ALLOC_DATA,
	};

	if (!(bmap_flags & BMAP_SET))
		*phys_blk = 0;

	if (ret_flags)
		*ret_flags = 0;

	/* Read inode structure if necessary */
	if (!inode) {
		retval = ext2fs_read_inode(fs, ino, &inode_buf);
		if (retval)
			return retval;
		inode = &inode_buf;
	}
	addr_per_block = (blk_t) fs->blocksize >> 2;

	if (ext2fs_file_block_offset_too_big(fs, inode, block))
		return EXT2_ET_FILE_TOO_BIG;

	/*
	 * If an inode has inline data, that means that it doesn't have
	 * any blocks and we shouldn't map any blocks for it.
	 */
	if (inode->i_flags & EXT4_INLINE_DATA_FL)
		return EXT2_ET_INLINE_DATA_NO_BLOCK;

	if (!block_buf) {
		retval = ext2fs_get_array(2, fs->blocksize, &buf);
		if (retval)
			return retval;
		block_buf = buf;
	}

	if (inode->i_flags & EXT4_EXTENTS_FL) {
		retval = ext2fs_extent_open2(fs, ino, inode, &handle);
		if (retval)
			goto done;
		retval = extent_bmap(fs, ino, inode, handle, block_buf,
				     bmap_flags, block, ret_flags,
				     &blocks_alloc, phys_blk);
		goto done;
	}

	if (block < EXT2_NDIR_BLOCKS) {
		if (bmap_flags & BMAP_SET) {
			b = *phys_blk;
			inode_bmap(inode, block) = b;
			inode_dirty++;
			goto done;
		}

		*phys_blk = inode_bmap(inode, block);
		b = block ? inode_bmap(inode, block - 1) :
			    ext2fs_find_inode_goal(fs, ino, inode, block);

		if ((*phys_blk == 0) && (bmap_flags & BMAP_ALLOC)) {
			b64 = b;
			retval = ext2fs_alloc_block3(fs, b64, block_buf, &b64,
						     &alloc_ctx);
			b = b64;
			if (retval)
				goto done;
			inode_bmap(inode, block) = b;
			blocks_alloc++;
			*phys_blk = b;
		}
		goto done;
	}

	/* Indirect block */
	block -= EXT2_NDIR_BLOCKS;
	blk32 = *phys_blk;
	if (block < addr_per_block) {
		b = inode_bmap(inode, EXT2_IND_BLOCK);
		if (!b) {
			if (!(bmap_flags & BMAP_ALLOC)) {
				if (bmap_flags & BMAP_SET)
					retval = EXT2_ET_SET_BMAP_NO_IND;
				goto done;
			}

			b = inode_bmap(inode, EXT2_IND_BLOCK-1);
			b64 = b;
			retval = ext2fs_alloc_block3(fs, b64, block_buf, &b64,
						     &alloc_ctx);
			b = b64;
			if (retval)
				goto done;
			inode_bmap(inode, EXT2_IND_BLOCK) = b;
			blocks_alloc++;
		}
		retval = block_ind_bmap(fs, bmap_flags, b, block_buf,
					&blocks_alloc, block, &blk32);
		if (retval == 0)
			*phys_blk = blk32;
		goto done;
	}

	/* Doubly indirect block  */
	block -= addr_per_block;
	if (block < addr_per_block * addr_per_block) {
		b = inode_bmap(inode, EXT2_DIND_BLOCK);
		if (!b) {
			if (!(bmap_flags & BMAP_ALLOC)) {
				if (bmap_flags & BMAP_SET)
					retval = EXT2_ET_SET_BMAP_NO_IND;
				goto done;
			}

			b = inode_bmap(inode, EXT2_IND_BLOCK);
			b64 = b;
			retval = ext2fs_alloc_block3(fs, b64, block_buf, &b64,
						     &alloc_ctx);
			b = b64;
			if (retval)
				goto done;
			inode_bmap(inode, EXT2_DIND_BLOCK) = b;
			blocks_alloc++;
		}
		retval = block_dind_bmap(fs, bmap_flags, b, block_buf,
					 &blocks_alloc, block, &blk32);
		if (retval == 0)
			*phys_blk = blk32;
		goto done;
	}

	/* Triply indirect block */
	block -= addr_per_block * addr_per_block;
	b = inode_bmap(inode, EXT2_TIND_BLOCK);
	if (!b) {
		if (!(bmap_flags & BMAP_ALLOC)) {
			if (bmap_flags & BMAP_SET)
				retval = EXT2_ET_SET_BMAP_NO_IND;
			goto done;
		}

		b = inode_bmap(inode, EXT2_DIND_BLOCK);
		b64 = b;
		retval = ext2fs_alloc_block3(fs, b64, block_buf, &b64,
					     &alloc_ctx);
		b = b64;
		if (retval)
			goto done;
		inode_bmap(inode, EXT2_TIND_BLOCK) = b;
		blocks_alloc++;
	}
	retval = block_tind_bmap(fs, bmap_flags, b, block_buf,
				 &blocks_alloc, block, &blk32);
	if (retval == 0)
		*phys_blk = blk32;
done:
	if (*phys_blk && retval == 0 && (bmap_flags & BMAP_ZERO))
		retval = ext2fs_zero_blocks2(fs, *phys_blk, 1, NULL, NULL);
	if (buf)
		ext2fs_free_mem(&buf);
	if (handle)
		ext2fs_extent_free(handle);
	if ((retval == 0) && (blocks_alloc || inode_dirty)) {
		ext2fs_iblk_add_blocks(fs, inode, blocks_alloc);
		retval = ext2fs_write_inode(fs, ino, inode);
	}
	return retval;
}

errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode,
		      char *block_buf, int bmap_flags, blk_t block,
		      blk_t *phys_blk)
{
	errcode_t ret;
	blk64_t	ret_blk = *phys_blk;

	ret = ext2fs_bmap2(fs, ino, inode, block_buf, bmap_flags, block,
			    0, &ret_blk);
	if (ret)
		return ret;
	if (ret_blk >= ((long long) 1 << 32))
		return EOVERFLOW;
	*phys_blk = ret_blk;
	return 0;
}
Commit	Line	Data
30fab293	1	/*
80e808fc	2	* bmap.c --- logical to physical block mapping
30fab293 TT	3	*
	4	* Copyright (C) 1997 Theodore Ts'o.
	5	*
	6	* %Begin-Header%
543547a5 TT	7	* This file may be redistributed under the terms of the GNU Library
543547a5 TT	8	* General Public License, version 2.
30fab293 TT	9	* %End-Header%
	10	*/
	11
d1154eb4	12	#include "config.h"
30fab293 TT	13	#include <stdio.h>
	14	#include <string.h>
	15	#if HAVE_UNISTD_H
	16	#include <unistd.h>
	17	#endif
cc9bf5d2	18	#include <errno.h>
30fab293	19
b5abe6fa	20	#include "ext2_fs.h"
f404167d	21	#include "ext2fsP.h"
30fab293	22
78d8f90f	23	#if defined(__GNUC__) && !defined(NO_INLINE_FUNCS)
30fab293 TT	24	#define _BMAP_INLINE_ __inline__
	25	#else
	26	#define _BMAP_INLINE_
	27	#endif
	28
31dbecd4	29	extern errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino,
efc6f628	30	struct ext2_inode *inode,
30fab293 TT	31	char *block_buf, int bmap_flags,
	32	blk_t block, blk_t *phys_blk);
	33
30fab293 TT	34	#define inode_bmap(inode, nr) ((inode)->i_block[(nr)])
30fab293 TT	35
efc6f628 TT	36	static _BMAP_INLINE_ errcode_t block_ind_bmap(ext2_filsys fs, int flags,
efc6f628 TT	37	blk_t ind, char *block_buf,
30fab293 TT	38	int *blocks_alloc,
	39	blk_t nr, blk_t *ret_blk)
	40	{
	41	errcode_t retval;
	42	blk_t b;
	43
	44	if (!ind) {
1d667534 TT	45	if (flags & BMAP_SET)
1d667534 TT	46	return EXT2_ET_SET_BMAP_NO_IND;
30fab293 TT	47	*ret_blk = 0;
	48	return 0;
	49	}
	50	retval = io_channel_read_blk(fs->io, ind, 1, block_buf);
	51	if (retval)
	52	return retval;
	53
1d667534 TT	54	if (flags & BMAP_SET) {
1d667534 TT	55	b = *ret_blk;
126a291c TT	56	#ifdef WORDS_BIGENDIAN
126a291c TT	57	b = ext2fs_swab32(b);
1d667534 TT	58	#endif
	59	((blk_t *) block_buf)[nr] = b;
	60	return io_channel_write_blk(fs->io, ind, 1, block_buf);
	61	}
	62
30fab293 TT	63	b = ((blk_t *) block_buf)[nr];
30fab293 TT	64
126a291c TT	65	#ifdef WORDS_BIGENDIAN
126a291c TT	66	b = ext2fs_swab32(b);
5df55d7f	67	#endif
30fab293 TT	68
30fab293 TT	69	if (!b && (flags & BMAP_ALLOC)) {
407916f5	70	b = nr ? ext2fs_le32_to_cpu(((blk_t *)block_buf)[nr - 1]) : ind;
30fab293 TT	71	retval = ext2fs_alloc_block(fs, b,
	72	block_buf + fs->blocksize, &b);
	73	if (retval)
	74	return retval;
	75
126a291c TT	76	#ifdef WORDS_BIGENDIAN
	77	((blk_t *) block_buf)[nr] = ext2fs_swab32(b);
	78	#else
	79	((blk_t *) block_buf)[nr] = b;
5df55d7f	80	#endif
30fab293 TT	81
	82	retval = io_channel_write_blk(fs->io, ind, 1, block_buf);
	83	if (retval)
	84	return retval;
	85
	86	(*blocks_alloc)++;
	87	}
	88
	89	*ret_blk = b;
	90	return 0;
	91	}
	92
546a1ff1	93	static _BMAP_INLINE_ errcode_t block_dind_bmap(ext2_filsys fs, int flags,
efc6f628	94	blk_t dind, char *block_buf,
30fab293 TT	95	int *blocks_alloc,
	96	blk_t nr, blk_t *ret_blk)
	97	{
1d6fd6d0	98	blk_t b = 0;
30fab293	99	errcode_t retval;
2eb374c9	100	blk_t addr_per_block;
efc6f628	101
2eb374c9	102	addr_per_block = (blk_t) fs->blocksize >> 2;
30fab293	103
efc6f628	104	retval = block_ind_bmap(fs, flags & ~BMAP_SET, dind, block_buf,
1d667534	105	blocks_alloc, nr / addr_per_block, &b);
30fab293 TT	106	if (retval)
	107	return retval;
	108	retval = block_ind_bmap(fs, flags, b, block_buf, blocks_alloc,
	109	nr % addr_per_block, ret_blk);
	110	return retval;
	111	}
	112
546a1ff1	113	static _BMAP_INLINE_ errcode_t block_tind_bmap(ext2_filsys fs, int flags,
efc6f628	114	blk_t tind, char *block_buf,
30fab293 TT	115	int *blocks_alloc,
	116	blk_t nr, blk_t *ret_blk)
	117	{
1d6fd6d0	118	blk_t b = 0;
30fab293	119	errcode_t retval;
2eb374c9	120	blk_t addr_per_block;
efc6f628	121
2eb374c9	122	addr_per_block = (blk_t) fs->blocksize >> 2;
30fab293	123
efc6f628	124	retval = block_dind_bmap(fs, flags & ~BMAP_SET, tind, block_buf,
1d667534	125	blocks_alloc, nr / addr_per_block, &b);
30fab293 TT	126	if (retval)
	127	return retval;
	128	retval = block_ind_bmap(fs, flags, b, block_buf, blocks_alloc,
	129	nr % addr_per_block, ret_blk);
	130	return retval;
	131	}
	132
8e8a190f TT	133	static errcode_t extent_bmap(ext2_filsys fs, ext2_ino_t ino,
	134	struct ext2_inode *inode,
	135	ext2_extent_handle_t handle,
	136	char *block_buf, int bmap_flags, blk64_t block,
	137	int ret_flags, int blocks_alloc,
	138	blk64_t *phys_blk);
	139
	140	static errcode_t implied_cluster_alloc(ext2_filsys fs, ext2_ino_t ino,
	141	struct ext2_inode *inode,
	142	ext2_extent_handle_t handle,
2a091427	143	blk64_t lblk, blk64_t *phys_blk)
8e8a190f TT	144	{
	145	blk64_t base_block, pblock = 0;
	146	int i;
	147
77b3e987	148	if (!ext2fs_has_feature_bigalloc(fs->super))
8e8a190f TT	149	return 0;
8e8a190f TT	150
2a091427 DW	151	base_block = lblk & ~EXT2FS_CLUSTER_MASK(fs);
	152	/*
	153	* Except for the logical block (lblk) that was passed in, search all
	154	* blocks in this logical cluster for a mapping to a physical cluster.
	155	* If any such map exists, calculate the physical block that maps to
	156	* the logical block and return that.
	157	*
	158	* The old code wouldn't even look if (block % cluster_ratio) == 0;
	159	* this is incorrect if we're allocating blocks in reverse order.
	160	*/
8e8a190f	161	for (i = 0; i < EXT2FS_CLUSTER_RATIO(fs); i++) {
2a091427 DW	162	if (base_block + i == lblk)
2a091427 DW	163	continue;
8e8a190f TT	164	extent_bmap(fs, ino, inode, handle, 0, 0,
	165	base_block + i, 0, 0, &pblock);
	166	if (pblock)
	167	break;
	168	}
	169	if (pblock == 0)
	170	return 0;
2a091427	171	*phys_blk = pblock - i + (lblk - base_block);
8e8a190f TT	172	return 0;
	173	}
	174
84397754 DW	175	/* Try to map a logical block to an already-allocated physical cluster. */
	176	errcode_t ext2fs_map_cluster_block(ext2_filsys fs, ext2_ino_t ino,
	177	struct ext2_inode *inode, blk64_t lblk,
	178	blk64_t *pblk)
	179	{
	180	ext2_extent_handle_t handle;
	181	errcode_t retval;
	182
	183	/* Need bigalloc and extents to be enabled */
	184	*pblk = 0;
77b3e987	185	if (!ext2fs_has_feature_bigalloc(fs->super) \|\|
84397754 DW	186	!(inode->i_flags & EXT4_EXTENTS_FL))
	187	return 0;
	188
	189	retval = ext2fs_extent_open2(fs, ino, inode, &handle);
	190	if (retval)
	191	goto out;
	192
	193	retval = implied_cluster_alloc(fs, ino, inode, handle, lblk, pblk);
	194	if (retval)
	195	goto out2;
	196
	197	out2:
	198	ext2fs_extent_free(handle);
	199	out:
	200	return retval;
	201	}
	202
551e2e46 TT	203	static errcode_t extent_bmap(ext2_filsys fs, ext2_ino_t ino,
	204	struct ext2_inode *inode,
	205	ext2_extent_handle_t handle,
	206	char *block_buf, int bmap_flags, blk64_t block,
	207	int ret_flags, int blocks_alloc,
	208	blk64_t *phys_blk)
	209	{
3fc46996	210	struct blk_alloc_ctx alloc_ctx;
551e2e46 TT	211	struct ext2fs_extent extent;
	212	unsigned int offset;
	213	errcode_t retval = 0;
8e8a190f TT	214	blk64_t blk64 = 0;
8e8a190f TT	215	int alloc = 0;
60a212f7 DW	216	int set_flags;
	217
	218	set_flags = bmap_flags & BMAP_UNINIT ? EXT2_EXTENT_SET_BMAP_UNINIT : 0;
551e2e46 TT	219
	220	if (bmap_flags & BMAP_SET) {
	221	retval = ext2fs_extent_set_bmap(handle, block,
60a212f7	222	*phys_blk, set_flags);
551e2e46 TT	223	return retval;
	224	}
	225	retval = ext2fs_extent_goto(handle, block);
	226	if (retval) {
	227	/* If the extent is not found, return phys_blk = 0 */
f23a1b7f TT	228	if (retval == EXT2_ET_EXTENT_NOT_FOUND) {
f23a1b7f TT	229	extent.e_lblk = block;
551e2e46	230	goto got_block;
f23a1b7f	231	}
551e2e46 TT	232	return retval;
	233	}
	234	retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
	235	if (retval)
	236	return retval;
	237	offset = block - extent.e_lblk;
	238	if (block >= extent.e_lblk && (offset <= extent.e_len)) {
	239	*phys_blk = extent.e_pblk + offset;
	240	if (ret_flags && extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT)
	241	*ret_flags \|= BMAP_RET_UNINIT;
	242	}
	243	got_block:
	244	if ((*phys_blk == 0) && (bmap_flags & BMAP_ALLOC)) {
8e8a190f TT	245	implied_cluster_alloc(fs, ino, inode, handle, block, &blk64);
	246	if (blk64)
	247	goto set_extent;
551e2e46 TT	248	retval = extent_bmap(fs, ino, inode, handle, block_buf,
	249	0, block-1, 0, blocks_alloc, &blk64);
	250	if (retval)
7b486ec0	251	blk64 = ext2fs_find_inode_goal(fs, ino, inode, block);
3fc46996 AS	252	alloc_ctx.ino = ino;
	253	alloc_ctx.inode = inode;
	254	alloc_ctx.lblk = extent.e_lblk;
	255	alloc_ctx.flags = BLOCK_ALLOC_DATA;
	256	retval = ext2fs_alloc_block3(fs, blk64, block_buf, &blk64,
	257	&alloc_ctx);
551e2e46 TT	258	if (retval)
551e2e46 TT	259	return retval;
8e8a190f TT	260	blk64 &= ~EXT2FS_CLUSTER_MASK(fs);
	261	blk64 += EXT2FS_CLUSTER_MASK(fs) & block;
	262	alloc++;
	263	set_extent:
551e2e46	264	retval = ext2fs_extent_set_bmap(handle, block,
60a212f7	265	blk64, set_flags);
6225a154 DW	266	if (retval) {
6225a154 DW	267	ext2fs_block_alloc_stats2(fs, blk64, -1);
551e2e46	268	return retval;
6225a154	269	}
551e2e46 TT	270	/* Update inode after setting extent */
	271	retval = ext2fs_read_inode(fs, ino, inode);
	272	if (retval)
	273	return retval;
8e8a190f	274	*blocks_alloc += alloc;
551e2e46 TT	275	*phys_blk = blk64;
	276	}
	277	return 0;
	278	}
	279
1e745149 DW	280	int ext2fs_file_block_offset_too_big(ext2_filsys fs,
	281	struct ext2_inode *inode,
	282	blk64_t offset)
	283	{
	284	blk64_t addr_per_block, max_map_block;
	285
	286	/* Kernel seems to cut us off at 4294967294 blocks */
	287	if (offset >= (1ULL << 32) - 1)
	288	return 1;
	289
	290	if (inode->i_flags & EXT4_EXTENTS_FL)
	291	return 0;
	292
	293	addr_per_block = fs->blocksize >> 2;
	294	max_map_block = addr_per_block;
	295	max_map_block += addr_per_block * addr_per_block;
	296	max_map_block += addr_per_block * addr_per_block * addr_per_block;
	297	max_map_block += 12;
	298
	299	return offset >= max_map_block;
	300	}
551e2e46	301
cc9bf5d2 TT	302	errcode_t ext2fs_bmap2(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode,
	303	char *block_buf, int bmap_flags, blk64_t block,
	304	int ret_flags, blk64_t phys_blk)
30fab293 TT	305	{
30fab293 TT	306	struct ext2_inode inode_buf;
cc9bf5d2	307	ext2_extent_handle_t handle = 0;
2eb374c9	308	blk_t addr_per_block;
cc9bf5d2	309	blk_t b, blk32;
3fc46996	310	blk64_t b64;
30fab293 TT	311	char *buf = 0;
30fab293 TT	312	errcode_t retval = 0;
1d667534	313	int blocks_alloc = 0, inode_dirty = 0;
3fc46996 AS	314	struct blk_alloc_ctx alloc_ctx = {
	315	.ino = ino,
	316	.inode = inode,
	317	.lblk = 0,
	318	.flags = BLOCK_ALLOC_DATA,
	319	};
30fab293	320
1d667534 TT	321	if (!(bmap_flags & BMAP_SET))
1d667534 TT	322	*phys_blk = 0;
30fab293	323
cc9bf5d2 TT	324	if (ret_flags)
	325	*ret_flags = 0;
	326
30fab293 TT	327	/* Read inode structure if necessary */
	328	if (!inode) {
	329	retval = ext2fs_read_inode(fs, ino, &inode_buf);
b38cd283	330	if (retval)
30fab293 TT	331	return retval;
	332	inode = &inode_buf;
	333	}
2eb374c9	334	addr_per_block = (blk_t) fs->blocksize >> 2;
30fab293	335
1e745149 DW	336	if (ext2fs_file_block_offset_too_big(fs, inode, block))
	337	return EXT2_ET_FILE_TOO_BIG;
	338
f5f6c020 ZL	339	/*
	340	* If an inode has inline data, that means that it doesn't have
	341	* any blocks and we shouldn't map any blocks for it.
	342	*/
	343	if (inode->i_flags & EXT4_INLINE_DATA_FL)
	344	return EXT2_ET_INLINE_DATA_NO_BLOCK;
	345
30fab293	346	if (!block_buf) {
ee01079a	347	retval = ext2fs_get_array(2, fs->blocksize, &buf);
7b4e4534 TT	348	if (retval)
7b4e4534 TT	349	return retval;
30fab293 TT	350	block_buf = buf;
	351	}
	352
551e2e46 TT	353	if (inode->i_flags & EXT4_EXTENTS_FL) {
	354	retval = ext2fs_extent_open2(fs, ino, inode, &handle);
	355	if (retval)
	356	goto done;
	357	retval = extent_bmap(fs, ino, inode, handle, block_buf,
	358	bmap_flags, block, ret_flags,
	359	&blocks_alloc, phys_blk);
	360	goto done;
	361	}
	362
30fab293	363	if (block < EXT2_NDIR_BLOCKS) {
1d667534 TT	364	if (bmap_flags & BMAP_SET) {
1d667534 TT	365	b = *phys_blk;
1d667534 TT	366	inode_bmap(inode, block) = b;
	367	inode_dirty++;
	368	goto done;
	369	}
	370
30fab293	371	*phys_blk = inode_bmap(inode, block);
7b486ec0 DW	372	b = block ? inode_bmap(inode, block - 1) :
7b486ec0 DW	373	ext2fs_find_inode_goal(fs, ino, inode, block);
efc6f628	374
30fab293	375	if ((*phys_blk == 0) && (bmap_flags & BMAP_ALLOC)) {
3fc46996 AS	376	b64 = b;
	377	retval = ext2fs_alloc_block3(fs, b64, block_buf, &b64,
	378	&alloc_ctx);
	379	b = b64;
30fab293 TT	380	if (retval)
	381	goto done;
	382	inode_bmap(inode, block) = b;
	383	blocks_alloc++;
	384	*phys_blk = b;
	385	}
	386	goto done;
	387	}
efc6f628	388
30fab293 TT	389	/* Indirect block */
30fab293 TT	390	block -= EXT2_NDIR_BLOCKS;
cc9bf5d2	391	blk32 = *phys_blk;
30fab293 TT	392	if (block < addr_per_block) {
	393	b = inode_bmap(inode, EXT2_IND_BLOCK);
	394	if (!b) {
1d667534 TT	395	if (!(bmap_flags & BMAP_ALLOC)) {
	396	if (bmap_flags & BMAP_SET)
	397	retval = EXT2_ET_SET_BMAP_NO_IND;
	398	goto done;
	399	}
30fab293 TT	400
30fab293 TT	401	b = inode_bmap(inode, EXT2_IND_BLOCK-1);
3fc46996 AS	402	b64 = b;
	403	retval = ext2fs_alloc_block3(fs, b64, block_buf, &b64,
	404	&alloc_ctx);
	405	b = b64;
30fab293 TT	406	if (retval)
	407	goto done;
	408	inode_bmap(inode, EXT2_IND_BLOCK) = b;
	409	blocks_alloc++;
	410	}
efc6f628	411	retval = block_ind_bmap(fs, bmap_flags, b, block_buf,
cc9bf5d2 TT	412	&blocks_alloc, block, &blk32);
	413	if (retval == 0)
	414	*phys_blk = blk32;
30fab293 TT	415	goto done;
30fab293 TT	416	}
efc6f628	417
30fab293 TT	418	/* Doubly indirect block */
	419	block -= addr_per_block;
	420	if (block < addr_per_block * addr_per_block) {
	421	b = inode_bmap(inode, EXT2_DIND_BLOCK);
	422	if (!b) {
1d667534 TT	423	if (!(bmap_flags & BMAP_ALLOC)) {
	424	if (bmap_flags & BMAP_SET)
	425	retval = EXT2_ET_SET_BMAP_NO_IND;
	426	goto done;
	427	}
30fab293 TT	428
30fab293 TT	429	b = inode_bmap(inode, EXT2_IND_BLOCK);
3fc46996 AS	430	b64 = b;
	431	retval = ext2fs_alloc_block3(fs, b64, block_buf, &b64,
	432	&alloc_ctx);
	433	b = b64;
30fab293 TT	434	if (retval)
	435	goto done;
	436	inode_bmap(inode, EXT2_DIND_BLOCK) = b;
	437	blocks_alloc++;
	438	}
efc6f628	439	retval = block_dind_bmap(fs, bmap_flags, b, block_buf,
cc9bf5d2 TT	440	&blocks_alloc, block, &blk32);
	441	if (retval == 0)
	442	*phys_blk = blk32;
30fab293 TT	443	goto done;
	444	}
	445
	446	/* Triply indirect block */
	447	block -= addr_per_block * addr_per_block;
	448	b = inode_bmap(inode, EXT2_TIND_BLOCK);
	449	if (!b) {
1d667534 TT	450	if (!(bmap_flags & BMAP_ALLOC)) {
	451	if (bmap_flags & BMAP_SET)
	452	retval = EXT2_ET_SET_BMAP_NO_IND;
30fab293	453	goto done;
1d667534	454	}
30fab293 TT	455
30fab293 TT	456	b = inode_bmap(inode, EXT2_DIND_BLOCK);
3fc46996 AS	457	b64 = b;
	458	retval = ext2fs_alloc_block3(fs, b64, block_buf, &b64,
	459	&alloc_ctx);
	460	b = b64;
30fab293 TT	461	if (retval)
	462	goto done;
	463	inode_bmap(inode, EXT2_TIND_BLOCK) = b;
	464	blocks_alloc++;
	465	}
efc6f628	466	retval = block_tind_bmap(fs, bmap_flags, b, block_buf,
cc9bf5d2 TT	467	&blocks_alloc, block, &blk32);
	468	if (retval == 0)
	469	*phys_blk = blk32;
30fab293	470	done:
60a212f7 DW	471	if (*phys_blk && retval == 0 && (bmap_flags & BMAP_ZERO))
60a212f7 DW	472	retval = ext2fs_zero_blocks2(fs, *phys_blk, 1, NULL, NULL);
30fab293	473	if (buf)
c4e3d3f3	474	ext2fs_free_mem(&buf);
cc9bf5d2 TT	475	if (handle)
cc9bf5d2 TT	476	ext2fs_extent_free(handle);
1d667534	477	if ((retval == 0) && (blocks_alloc \|\| inode_dirty)) {
1ca1059f	478	ext2fs_iblk_add_blocks(fs, inode, blocks_alloc);
30fab293 TT	479	retval = ext2fs_write_inode(fs, ino, inode);
	480	}
	481	return retval;
	482	}
	483
cc9bf5d2 TT	484	errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode,
	485	char *block_buf, int bmap_flags, blk_t block,
	486	blk_t *phys_blk)
	487	{
	488	errcode_t ret;
9c9e1d5f	489	blk64_t ret_blk = *phys_blk;
cc9bf5d2 TT	490
	491	ret = ext2fs_bmap2(fs, ino, inode, block_buf, bmap_flags, block,
	492	0, &ret_blk);
	493	if (ret)
	494	return ret;
	495	if (ret_blk >= ((long long) 1 << 32))
	496	return EOVERFLOW;
	497	*phys_blk = ret_blk;
	498	return 0;
	499	}