[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 "ext2fs.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 ? ((blk_t *) block_buf)[nr-1] : 0;
		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 (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
					EXT4_FEATURE_RO_COMPAT_BIGALLOC))
		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 (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
					EXT4_FEATURE_RO_COMPAT_BIGALLOC) ||
	    !(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 ext2fs_extent	extent;
	unsigned int		offset;
	errcode_t		retval = 0;
	blk64_t			blk64 = 0;
	int			alloc = 0;

	if (bmap_flags & BMAP_SET) {
		retval = ext2fs_extent_set_bmap(handle, block,
						*phys_blk, 0);
		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)
			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 = 0;
		retval = ext2fs_alloc_block2(fs, blk64, block_buf,
					     &blk64);
		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, 0);
		if (retval)
			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;
	char	*buf = 0;
	errcode_t	retval = 0;
	int		blocks_alloc = 0, inode_dirty = 0;

	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 (!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) : 0;

		if ((*phys_blk == 0) && (bmap_flags & BMAP_ALLOC)) {
			retval = ext2fs_alloc_block(fs, b, block_buf, &b);
			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);
 			retval = ext2fs_alloc_block(fs, b, block_buf, &b);
			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);
 			retval = ext2fs_alloc_block(fs, b, block_buf, &b);
			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);
		retval = ext2fs_alloc_block(fs, b, block_buf, &b);
		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 (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"
30fab293 TT	21	#include "ext2fs.h"
30fab293 TT	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
	69	if (!b && (flags & BMAP_ALLOC)) {
	70	b = nr ? ((blk_t *) block_buf)[nr-1] : 0;
	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
	148	if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
	149	EXT4_FEATURE_RO_COMPAT_BIGALLOC))
	150	return 0;
	151
2a091427 DW	152	base_block = lblk & ~EXT2FS_CLUSTER_MASK(fs);
	153	/*
	154	* Except for the logical block (lblk) that was passed in, search all
	155	* blocks in this logical cluster for a mapping to a physical cluster.
	156	* If any such map exists, calculate the physical block that maps to
	157	* the logical block and return that.
	158	*
	159	* The old code wouldn't even look if (block % cluster_ratio) == 0;
	160	* this is incorrect if we're allocating blocks in reverse order.
	161	*/
8e8a190f	162	for (i = 0; i < EXT2FS_CLUSTER_RATIO(fs); i++) {
2a091427 DW	163	if (base_block + i == lblk)
2a091427 DW	164	continue;
8e8a190f TT	165	extent_bmap(fs, ino, inode, handle, 0, 0,
	166	base_block + i, 0, 0, &pblock);
	167	if (pblock)
	168	break;
	169	}
	170	if (pblock == 0)
	171	return 0;
2a091427	172	*phys_blk = pblock - i + (lblk - base_block);
8e8a190f TT	173	return 0;
	174	}
	175
84397754 DW	176	/* Try to map a logical block to an already-allocated physical cluster. */
	177	errcode_t ext2fs_map_cluster_block(ext2_filsys fs, ext2_ino_t ino,
	178	struct ext2_inode *inode, blk64_t lblk,
	179	blk64_t *pblk)
	180	{
	181	ext2_extent_handle_t handle;
	182	errcode_t retval;
	183
	184	/* Need bigalloc and extents to be enabled */
	185	*pblk = 0;
	186	if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
	187	EXT4_FEATURE_RO_COMPAT_BIGALLOC) \|\|
	188	!(inode->i_flags & EXT4_EXTENTS_FL))
	189	return 0;
	190
	191	retval = ext2fs_extent_open2(fs, ino, inode, &handle);
	192	if (retval)
	193	goto out;
	194
	195	retval = implied_cluster_alloc(fs, ino, inode, handle, lblk, pblk);
	196	if (retval)
	197	goto out2;
	198
	199	out2:
	200	ext2fs_extent_free(handle);
	201	out:
	202	return retval;
	203	}
	204
551e2e46 TT	205	static errcode_t extent_bmap(ext2_filsys fs, ext2_ino_t ino,
	206	struct ext2_inode *inode,
	207	ext2_extent_handle_t handle,
	208	char *block_buf, int bmap_flags, blk64_t block,
	209	int ret_flags, int blocks_alloc,
	210	blk64_t *phys_blk)
	211	{
	212	struct ext2fs_extent extent;
	213	unsigned int offset;
	214	errcode_t retval = 0;
8e8a190f TT	215	blk64_t blk64 = 0;
8e8a190f TT	216	int alloc = 0;
551e2e46 TT	217
	218	if (bmap_flags & BMAP_SET) {
	219	retval = ext2fs_extent_set_bmap(handle, block,
	220	*phys_blk, 0);
	221	return retval;
	222	}
	223	retval = ext2fs_extent_goto(handle, block);
	224	if (retval) {
	225	/* If the extent is not found, return phys_blk = 0 */
	226	if (retval == EXT2_ET_EXTENT_NOT_FOUND)
	227	goto got_block;
	228	return retval;
	229	}
	230	retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
	231	if (retval)
	232	return retval;
	233	offset = block - extent.e_lblk;
	234	if (block >= extent.e_lblk && (offset <= extent.e_len)) {
	235	*phys_blk = extent.e_pblk + offset;
	236	if (ret_flags && extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT)
	237	*ret_flags \|= BMAP_RET_UNINIT;
	238	}
	239	got_block:
	240	if ((*phys_blk == 0) && (bmap_flags & BMAP_ALLOC)) {
8e8a190f TT	241	implied_cluster_alloc(fs, ino, inode, handle, block, &blk64);
	242	if (blk64)
	243	goto set_extent;
551e2e46 TT	244	retval = extent_bmap(fs, ino, inode, handle, block_buf,
	245	0, block-1, 0, blocks_alloc, &blk64);
	246	if (retval)
	247	blk64 = 0;
	248	retval = ext2fs_alloc_block2(fs, blk64, block_buf,
	249	&blk64);
	250	if (retval)
	251	return retval;
8e8a190f TT	252	blk64 &= ~EXT2FS_CLUSTER_MASK(fs);
	253	blk64 += EXT2FS_CLUSTER_MASK(fs) & block;
	254	alloc++;
	255	set_extent:
551e2e46 TT	256	retval = ext2fs_extent_set_bmap(handle, block,
	257	blk64, 0);
	258	if (retval)
	259	return retval;
	260	/* Update inode after setting extent */
	261	retval = ext2fs_read_inode(fs, ino, inode);
	262	if (retval)
	263	return retval;
8e8a190f	264	*blocks_alloc += alloc;
551e2e46 TT	265	*phys_blk = blk64;
	266	}
	267	return 0;
	268	}
	269
1e745149 DW	270	int ext2fs_file_block_offset_too_big(ext2_filsys fs,
	271	struct ext2_inode *inode,
	272	blk64_t offset)
	273	{
	274	blk64_t addr_per_block, max_map_block;
	275
	276	/* Kernel seems to cut us off at 4294967294 blocks */
	277	if (offset >= (1ULL << 32) - 1)
	278	return 1;
	279
	280	if (inode->i_flags & EXT4_EXTENTS_FL)
	281	return 0;
	282
	283	addr_per_block = fs->blocksize >> 2;
	284	max_map_block = addr_per_block;
	285	max_map_block += addr_per_block * addr_per_block;
	286	max_map_block += addr_per_block * addr_per_block * addr_per_block;
	287	max_map_block += 12;
	288
	289	return offset >= max_map_block;
	290	}
551e2e46	291
cc9bf5d2 TT	292	errcode_t ext2fs_bmap2(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode,
	293	char *block_buf, int bmap_flags, blk64_t block,
	294	int ret_flags, blk64_t phys_blk)
30fab293 TT	295	{
30fab293 TT	296	struct ext2_inode inode_buf;
cc9bf5d2	297	ext2_extent_handle_t handle = 0;
2eb374c9	298	blk_t addr_per_block;
cc9bf5d2	299	blk_t b, blk32;
30fab293 TT	300	char *buf = 0;
30fab293 TT	301	errcode_t retval = 0;
1d667534	302	int blocks_alloc = 0, inode_dirty = 0;
30fab293	303
1d667534 TT	304	if (!(bmap_flags & BMAP_SET))
1d667534 TT	305	*phys_blk = 0;
30fab293	306
cc9bf5d2 TT	307	if (ret_flags)
	308	*ret_flags = 0;
	309
30fab293 TT	310	/* Read inode structure if necessary */
	311	if (!inode) {
	312	retval = ext2fs_read_inode(fs, ino, &inode_buf);
b38cd283	313	if (retval)
30fab293 TT	314	return retval;
	315	inode = &inode_buf;
	316	}
2eb374c9	317	addr_per_block = (blk_t) fs->blocksize >> 2;
30fab293	318
1e745149 DW	319	if (ext2fs_file_block_offset_too_big(fs, inode, block))
	320	return EXT2_ET_FILE_TOO_BIG;
	321
30fab293	322	if (!block_buf) {
ee01079a	323	retval = ext2fs_get_array(2, fs->blocksize, &buf);
7b4e4534 TT	324	if (retval)
7b4e4534 TT	325	return retval;
30fab293 TT	326	block_buf = buf;
	327	}
	328
551e2e46 TT	329	if (inode->i_flags & EXT4_EXTENTS_FL) {
	330	retval = ext2fs_extent_open2(fs, ino, inode, &handle);
	331	if (retval)
	332	goto done;
	333	retval = extent_bmap(fs, ino, inode, handle, block_buf,
	334	bmap_flags, block, ret_flags,
	335	&blocks_alloc, phys_blk);
	336	goto done;
	337	}
	338
30fab293	339	if (block < EXT2_NDIR_BLOCKS) {
1d667534 TT	340	if (bmap_flags & BMAP_SET) {
1d667534 TT	341	b = *phys_blk;
1d667534 TT	342	inode_bmap(inode, block) = b;
	343	inode_dirty++;
	344	goto done;
	345	}
	346
30fab293 TT	347	*phys_blk = inode_bmap(inode, block);
30fab293 TT	348	b = block ? inode_bmap(inode, block-1) : 0;
efc6f628	349
30fab293 TT	350	if ((*phys_blk == 0) && (bmap_flags & BMAP_ALLOC)) {
	351	retval = ext2fs_alloc_block(fs, b, block_buf, &b);
	352	if (retval)
	353	goto done;
	354	inode_bmap(inode, block) = b;
	355	blocks_alloc++;
	356	*phys_blk = b;
	357	}
	358	goto done;
	359	}
efc6f628	360
30fab293 TT	361	/* Indirect block */
30fab293 TT	362	block -= EXT2_NDIR_BLOCKS;
cc9bf5d2	363	blk32 = *phys_blk;
30fab293 TT	364	if (block < addr_per_block) {
	365	b = inode_bmap(inode, EXT2_IND_BLOCK);
	366	if (!b) {
1d667534 TT	367	if (!(bmap_flags & BMAP_ALLOC)) {
	368	if (bmap_flags & BMAP_SET)
	369	retval = EXT2_ET_SET_BMAP_NO_IND;
	370	goto done;
	371	}
30fab293 TT	372
	373	b = inode_bmap(inode, EXT2_IND_BLOCK-1);
	374	retval = ext2fs_alloc_block(fs, b, block_buf, &b);
	375	if (retval)
	376	goto done;
	377	inode_bmap(inode, EXT2_IND_BLOCK) = b;
	378	blocks_alloc++;
	379	}
efc6f628	380	retval = block_ind_bmap(fs, bmap_flags, b, block_buf,
cc9bf5d2 TT	381	&blocks_alloc, block, &blk32);
	382	if (retval == 0)
	383	*phys_blk = blk32;
30fab293 TT	384	goto done;
30fab293 TT	385	}
efc6f628	386
30fab293 TT	387	/* Doubly indirect block */
	388	block -= addr_per_block;
	389	if (block < addr_per_block * addr_per_block) {
	390	b = inode_bmap(inode, EXT2_DIND_BLOCK);
	391	if (!b) {
1d667534 TT	392	if (!(bmap_flags & BMAP_ALLOC)) {
	393	if (bmap_flags & BMAP_SET)
	394	retval = EXT2_ET_SET_BMAP_NO_IND;
	395	goto done;
	396	}
30fab293 TT	397
	398	b = inode_bmap(inode, EXT2_IND_BLOCK);
	399	retval = ext2fs_alloc_block(fs, b, block_buf, &b);
	400	if (retval)
	401	goto done;
	402	inode_bmap(inode, EXT2_DIND_BLOCK) = b;
	403	blocks_alloc++;
	404	}
efc6f628	405	retval = block_dind_bmap(fs, bmap_flags, b, block_buf,
cc9bf5d2 TT	406	&blocks_alloc, block, &blk32);
	407	if (retval == 0)
	408	*phys_blk = blk32;
30fab293 TT	409	goto done;
	410	}
	411
	412	/* Triply indirect block */
	413	block -= addr_per_block * addr_per_block;
	414	b = inode_bmap(inode, EXT2_TIND_BLOCK);
	415	if (!b) {
1d667534 TT	416	if (!(bmap_flags & BMAP_ALLOC)) {
	417	if (bmap_flags & BMAP_SET)
	418	retval = EXT2_ET_SET_BMAP_NO_IND;
30fab293	419	goto done;
1d667534	420	}
30fab293 TT	421
	422	b = inode_bmap(inode, EXT2_DIND_BLOCK);
	423	retval = ext2fs_alloc_block(fs, b, block_buf, &b);
	424	if (retval)
	425	goto done;
	426	inode_bmap(inode, EXT2_TIND_BLOCK) = b;
	427	blocks_alloc++;
	428	}
efc6f628	429	retval = block_tind_bmap(fs, bmap_flags, b, block_buf,
cc9bf5d2 TT	430	&blocks_alloc, block, &blk32);
	431	if (retval == 0)
	432	*phys_blk = blk32;
30fab293 TT	433	done:
30fab293 TT	434	if (buf)
c4e3d3f3	435	ext2fs_free_mem(&buf);
cc9bf5d2 TT	436	if (handle)
cc9bf5d2 TT	437	ext2fs_extent_free(handle);
1d667534	438	if ((retval == 0) && (blocks_alloc \|\| inode_dirty)) {
1ca1059f	439	ext2fs_iblk_add_blocks(fs, inode, blocks_alloc);
30fab293 TT	440	retval = ext2fs_write_inode(fs, ino, inode);
	441	}
	442	return retval;
	443	}
	444
cc9bf5d2 TT	445	errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode,
	446	char *block_buf, int bmap_flags, blk_t block,
	447	blk_t *phys_blk)
	448	{
	449	errcode_t ret;
9c9e1d5f	450	blk64_t ret_blk = *phys_blk;
cc9bf5d2 TT	451
	452	ret = ext2fs_bmap2(fs, ino, inode, block_buf, bmap_flags, block,
	453	0, &ret_blk);
	454	if (ret)
	455	return ret;
	456	if (ret_blk >= ((long long) 1 << 32))
	457	return EOVERFLOW;
	458	*phys_blk = ret_blk;
	459	return 0;
	460	}