You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
500 lines
12 KiB
500 lines
12 KiB
/*
|
|
* 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;
|
|
}
|