android13/external/e2fsprogs/lib/ext2fs/rw_bitmaps.c

680 lines
17 KiB
C

/*
* rw_bitmaps.c --- routines to read and write the inode and block bitmaps.
*
* Copyright (C) 1993, 1994, 1994, 1996 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 <fcntl.h>
#include <time.h>
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_PTHREAD_H
#include <pthread.h>
#endif
#include "ext2_fs.h"
#include "ext2fs.h"
#include "e2image.h"
#ifdef HAVE_PTHREAD
typedef pthread_mutex_t mutex_t;
static void unix_pthread_mutex_lock(mutex_t *mutex)
{
if (mutex)
pthread_mutex_lock(mutex);
}
static void unix_pthread_mutex_unlock(mutex_t *mutex)
{
if (mutex)
pthread_mutex_unlock(mutex);
}
#else
typedef int mutex_t;
#define unix_pthread_mutex_lock(mutex_t) do {} while (0)
#define unix_pthread_mutex_unlock(mutex_t) do {} while (0)
#endif
static errcode_t write_bitmaps(ext2_filsys fs, int do_inode, int do_block)
{
dgrp_t i;
unsigned int j;
int block_nbytes, inode_nbytes;
unsigned int nbits;
errcode_t retval;
char *block_buf = NULL, *inode_buf = NULL;
int csum_flag;
blk64_t blk;
blk64_t blk_itr = EXT2FS_B2C(fs, fs->super->s_first_data_block);
ext2_ino_t ino_itr = 1;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (!(fs->flags & EXT2_FLAG_RW))
return EXT2_ET_RO_FILSYS;
csum_flag = ext2fs_has_group_desc_csum(fs);
inode_nbytes = block_nbytes = 0;
if (do_block) {
block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8;
retval = io_channel_alloc_buf(fs->io, 0, &block_buf);
if (retval)
goto errout;
memset(block_buf, 0xff, fs->blocksize);
}
if (do_inode) {
inode_nbytes = (size_t)
((EXT2_INODES_PER_GROUP(fs->super)+7) / 8);
retval = io_channel_alloc_buf(fs->io, 0, &inode_buf);
if (retval)
goto errout;
memset(inode_buf, 0xff, fs->blocksize);
}
for (i = 0; i < fs->group_desc_count; i++) {
if (!do_block)
goto skip_block_bitmap;
if (csum_flag && ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT)
)
goto skip_this_block_bitmap;
retval = ext2fs_get_block_bitmap_range2(fs->block_map,
blk_itr, block_nbytes << 3, block_buf);
if (retval)
goto errout;
if (i == fs->group_desc_count - 1) {
/* Force bitmap padding for the last group */
nbits = EXT2FS_NUM_B2C(fs,
((ext2fs_blocks_count(fs->super)
- (__u64) fs->super->s_first_data_block)
% (__u64) EXT2_BLOCKS_PER_GROUP(fs->super)));
if (nbits)
for (j = nbits; j < fs->blocksize * 8; j++)
ext2fs_set_bit(j, block_buf);
}
retval = ext2fs_block_bitmap_csum_set(fs, i, block_buf,
block_nbytes);
if (retval)
return retval;
ext2fs_group_desc_csum_set(fs, i);
fs->flags |= EXT2_FLAG_DIRTY;
blk = ext2fs_block_bitmap_loc(fs, i);
if (blk) {
retval = io_channel_write_blk64(fs->io, blk, 1,
block_buf);
if (retval) {
retval = EXT2_ET_BLOCK_BITMAP_WRITE;
goto errout;
}
}
skip_this_block_bitmap:
blk_itr += block_nbytes << 3;
skip_block_bitmap:
if (!do_inode)
continue;
if (csum_flag && ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT)
)
goto skip_this_inode_bitmap;
retval = ext2fs_get_inode_bitmap_range2(fs->inode_map,
ino_itr, inode_nbytes << 3, inode_buf);
if (retval)
goto errout;
retval = ext2fs_inode_bitmap_csum_set(fs, i, inode_buf,
inode_nbytes);
if (retval)
goto errout;
ext2fs_group_desc_csum_set(fs, i);
fs->flags |= EXT2_FLAG_DIRTY;
blk = ext2fs_inode_bitmap_loc(fs, i);
if (blk) {
retval = io_channel_write_blk64(fs->io, blk, 1,
inode_buf);
if (retval) {
retval = EXT2_ET_INODE_BITMAP_WRITE;
goto errout;
}
}
skip_this_inode_bitmap:
ino_itr += inode_nbytes << 3;
}
if (do_block) {
fs->flags &= ~EXT2_FLAG_BB_DIRTY;
ext2fs_free_mem(&block_buf);
}
if (do_inode) {
fs->flags &= ~EXT2_FLAG_IB_DIRTY;
ext2fs_free_mem(&inode_buf);
}
return 0;
errout:
if (inode_buf)
ext2fs_free_mem(&inode_buf);
if (block_buf)
ext2fs_free_mem(&block_buf);
return retval;
}
static errcode_t mark_uninit_bg_group_blocks(ext2_filsys fs)
{
dgrp_t i;
blk64_t blk;
ext2fs_block_bitmap bmap = fs->block_map;
for (i = 0; i < fs->group_desc_count; i++) {
if (!ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT))
continue;
ext2fs_reserve_super_and_bgd(fs, i, bmap);
/*
* Mark the blocks used for the inode table
*/
blk = ext2fs_inode_table_loc(fs, i);
if (blk)
ext2fs_mark_block_bitmap_range2(bmap, blk,
fs->inode_blocks_per_group);
/*
* Mark block used for the block bitmap
*/
blk = ext2fs_block_bitmap_loc(fs, i);
if (blk)
ext2fs_mark_block_bitmap2(bmap, blk);
/*
* Mark block used for the inode bitmap
*/
blk = ext2fs_inode_bitmap_loc(fs, i);
if (blk)
ext2fs_mark_block_bitmap2(bmap, blk);
}
return 0;
}
static int bitmap_tail_verify(unsigned char *bitmap, int first, int last)
{
int i;
for (i = first; i <= last; i++)
if (bitmap[i] != 0xff)
return 0;
return 1;
}
static errcode_t read_bitmaps_range_prepare(ext2_filsys fs, int flags)
{
errcode_t retval;
int block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8;
int inode_nbytes = EXT2_INODES_PER_GROUP(fs->super) / 8;
char *buf;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if ((block_nbytes > (int) fs->blocksize) ||
(inode_nbytes > (int) fs->blocksize))
return EXT2_ET_CORRUPT_SUPERBLOCK;
fs->write_bitmaps = ext2fs_write_bitmaps;
retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf);
if (retval)
return retval;
if (flags & EXT2FS_BITMAPS_BLOCK) {
if (fs->block_map)
ext2fs_free_block_bitmap(fs->block_map);
strcpy(buf, "block bitmap for ");
strcat(buf, fs->device_name);
retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map);
if (retval)
goto cleanup;
}
if (flags & EXT2FS_BITMAPS_INODE) {
if (fs->inode_map)
ext2fs_free_inode_bitmap(fs->inode_map);
strcpy(buf, "inode bitmap for ");
strcat(buf, fs->device_name);
retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
if (retval)
goto cleanup;
}
ext2fs_free_mem(&buf);
return retval;
cleanup:
if (flags & EXT2FS_BITMAPS_BLOCK) {
ext2fs_free_block_bitmap(fs->block_map);
fs->block_map = 0;
}
if (flags & EXT2FS_BITMAPS_INODE) {
ext2fs_free_inode_bitmap(fs->inode_map);
fs->inode_map = 0;
}
ext2fs_free_mem(&buf);
return retval;
}
static errcode_t read_bitmaps_range_start(ext2_filsys fs, int flags,
dgrp_t start, dgrp_t end,
mutex_t *mutex,
int *tail_flags)
{
dgrp_t i;
char *block_bitmap = 0, *inode_bitmap = 0;
errcode_t retval = 0;
int block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8;
int inode_nbytes = EXT2_INODES_PER_GROUP(fs->super) / 8;
int csum_flag;
unsigned int cnt;
blk64_t blk;
blk64_t blk_itr = EXT2FS_B2C(fs, fs->super->s_first_data_block);
blk64_t blk_cnt;
ext2_ino_t ino_itr = 1;
ext2_ino_t ino_cnt;
csum_flag = ext2fs_has_group_desc_csum(fs);
if (flags & EXT2FS_BITMAPS_BLOCK) {
retval = io_channel_alloc_buf(fs->io, 0, &block_bitmap);
if (retval)
goto cleanup;
} else {
block_nbytes = 0;
}
if (flags & EXT2FS_BITMAPS_INODE) {
retval = io_channel_alloc_buf(fs->io, 0, &inode_bitmap);
if (retval)
goto cleanup;
} else {
inode_nbytes = 0;
}
/* io should be null */
if (fs->flags & EXT2_FLAG_IMAGE_FILE) {
blk = (ext2fs_le32_to_cpu(fs->image_header->offset_inodemap) / fs->blocksize);
ino_cnt = fs->super->s_inodes_count;
while (inode_bitmap && ino_cnt > 0) {
retval = io_channel_read_blk64(fs->image_io, blk++,
1, inode_bitmap);
if (retval)
goto cleanup;
cnt = fs->blocksize << 3;
if (cnt > ino_cnt)
cnt = ino_cnt;
retval = ext2fs_set_inode_bitmap_range2(fs->inode_map,
ino_itr, cnt, inode_bitmap);
if (retval)
goto cleanup;
ino_itr += cnt;
ino_cnt -= cnt;
}
blk = (ext2fs_le32_to_cpu(fs->image_header->offset_blockmap) /
fs->blocksize);
blk_cnt = EXT2_GROUPS_TO_CLUSTERS(fs->super,
fs->group_desc_count);
while (block_bitmap && blk_cnt > 0) {
retval = io_channel_read_blk64(fs->image_io, blk++,
1, block_bitmap);
if (retval)
goto cleanup;
cnt = fs->blocksize << 3;
if (cnt > blk_cnt)
cnt = blk_cnt;
retval = ext2fs_set_block_bitmap_range2(fs->block_map,
blk_itr, cnt, block_bitmap);
if (retval)
goto cleanup;
blk_itr += cnt;
blk_cnt -= cnt;
}
goto cleanup;
}
blk_itr += ((blk64_t)start * (block_nbytes << 3));
ino_itr += ((blk64_t)start * (inode_nbytes << 3));
for (i = start; i <= end; i++) {
if (block_bitmap) {
blk = ext2fs_block_bitmap_loc(fs, i);
if ((csum_flag &&
ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT) &&
ext2fs_group_desc_csum_verify(fs, i)) ||
(blk >= ext2fs_blocks_count(fs->super)))
blk = 0;
if (blk) {
retval = io_channel_read_blk64(fs->io, blk,
1, block_bitmap);
if (retval) {
retval = EXT2_ET_BLOCK_BITMAP_READ;
goto cleanup;
}
/* verify block bitmap checksum */
if (!(fs->flags &
EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
!ext2fs_block_bitmap_csum_verify(fs, i,
block_bitmap, block_nbytes)) {
retval =
EXT2_ET_BLOCK_BITMAP_CSUM_INVALID;
goto cleanup;
}
if (!bitmap_tail_verify((unsigned char *) block_bitmap,
block_nbytes, fs->blocksize - 1))
*tail_flags |= EXT2_FLAG_BBITMAP_TAIL_PROBLEM;
} else
memset(block_bitmap, 0, block_nbytes);
cnt = block_nbytes << 3;
unix_pthread_mutex_lock(mutex);
retval = ext2fs_set_block_bitmap_range2(fs->block_map,
blk_itr, cnt, block_bitmap);
unix_pthread_mutex_unlock(mutex);
if (retval)
goto cleanup;
blk_itr += block_nbytes << 3;
}
if (inode_bitmap) {
blk = ext2fs_inode_bitmap_loc(fs, i);
if ((csum_flag &&
ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT) &&
ext2fs_group_desc_csum_verify(fs, i)) ||
(blk >= ext2fs_blocks_count(fs->super)))
blk = 0;
if (blk) {
retval = io_channel_read_blk64(fs->io, blk,
1, inode_bitmap);
if (retval) {
retval = EXT2_ET_INODE_BITMAP_READ;
goto cleanup;
}
/* verify inode bitmap checksum */
if (!(fs->flags &
EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
!ext2fs_inode_bitmap_csum_verify(fs, i,
inode_bitmap, inode_nbytes)) {
retval =
EXT2_ET_INODE_BITMAP_CSUM_INVALID;
goto cleanup;
}
if (!bitmap_tail_verify((unsigned char *) inode_bitmap,
inode_nbytes, fs->blocksize - 1))
*tail_flags |= EXT2_FLAG_IBITMAP_TAIL_PROBLEM;
} else
memset(inode_bitmap, 0, inode_nbytes);
cnt = inode_nbytes << 3;
unix_pthread_mutex_lock(mutex);
retval = ext2fs_set_inode_bitmap_range2(fs->inode_map,
ino_itr, cnt, inode_bitmap);
unix_pthread_mutex_unlock(mutex);
if (retval)
goto cleanup;
ino_itr += inode_nbytes << 3;
}
}
cleanup:
if (inode_bitmap)
ext2fs_free_mem(&inode_bitmap);
if (block_bitmap)
ext2fs_free_mem(&block_bitmap);
return retval;
}
static errcode_t read_bitmaps_range_end(ext2_filsys fs, int flags,
int tail_flags)
{
errcode_t retval;
/* Mark group blocks for any BLOCK_UNINIT groups */
if (flags & EXT2FS_BITMAPS_BLOCK) {
retval = mark_uninit_bg_group_blocks(fs);
if (retval)
return retval;
fs->flags &= ~EXT2_FLAG_BBITMAP_TAIL_PROBLEM;
}
if (flags & EXT2FS_BITMAPS_INODE)
fs->flags &= ~EXT2_FLAG_IBITMAP_TAIL_PROBLEM;
fs->flags |= tail_flags;
return 0;
}
static void read_bitmaps_cleanup_on_error(ext2_filsys fs, int flags)
{
if (flags & EXT2FS_BITMAPS_BLOCK) {
ext2fs_free_block_bitmap(fs->block_map);
fs->block_map = 0;
}
if (flags & EXT2FS_BITMAPS_INODE) {
ext2fs_free_inode_bitmap(fs->inode_map);
fs->inode_map = 0;
}
}
static errcode_t read_bitmaps_range(ext2_filsys fs, int flags,
dgrp_t start, dgrp_t end)
{
errcode_t retval;
int tail_flags = 0;
retval = read_bitmaps_range_prepare(fs, flags);
if (retval)
return retval;
retval = read_bitmaps_range_start(fs, flags, start, end,
NULL, &tail_flags);
if (retval == 0)
retval = read_bitmaps_range_end(fs, flags, tail_flags);
if (retval)
read_bitmaps_cleanup_on_error(fs, flags);
return retval;
}
#ifdef HAVE_PTHREAD
struct read_bitmaps_thread_info {
ext2_filsys rbt_fs;
int rbt_flags;
dgrp_t rbt_grp_start;
dgrp_t rbt_grp_end;
errcode_t rbt_retval;
pthread_mutex_t *rbt_mutex;
int rbt_tail_flags;
};
static void *read_bitmaps_thread(void *data)
{
struct read_bitmaps_thread_info *rbt = data;
rbt->rbt_retval = read_bitmaps_range_start(rbt->rbt_fs, rbt->rbt_flags,
rbt->rbt_grp_start, rbt->rbt_grp_end,
rbt->rbt_mutex, &rbt->rbt_tail_flags);
return NULL;
}
#endif
errcode_t ext2fs_rw_bitmaps(ext2_filsys fs, int flags, int num_threads)
{
#ifdef HAVE_PTHREAD
pthread_attr_t attr;
pthread_t *thread_ids = NULL;
struct read_bitmaps_thread_info *thread_infos = NULL;
pthread_mutex_t rbt_mutex = PTHREAD_MUTEX_INITIALIZER;
errcode_t retval;
errcode_t rc;
unsigned flexbg_size = 1 << fs->super->s_log_groups_per_flex;
dgrp_t average_group;
int i, tail_flags = 0;
#endif
if (flags & ~EXT2FS_BITMAPS_VALID_FLAGS)
return EXT2_ET_INVALID_ARGUMENT;
if (flags & EXT2FS_BITMAPS_WRITE)
return write_bitmaps(fs, flags & EXT2FS_BITMAPS_INODE,
flags & EXT2FS_BITMAPS_BLOCK);
#ifdef HAVE_PTHREAD
if (((fs->io->flags & CHANNEL_FLAGS_THREADS) == 0) ||
(num_threads == 1) || (fs->flags & EXT2_FLAG_IMAGE_FILE))
goto fallback;
#if defined(HAVE_SYSCONF) && defined(_SC_NPROCESSORS_CONF)
if (num_threads < 0)
num_threads = sysconf(_SC_NPROCESSORS_CONF);
#endif
/*
* Guess for now; eventually we should probably define
* ext2fs_get_num_cpus() and teach it how to get this info on
* MacOS, FreeBSD, etc.
* ref: https://stackoverflow.com/questions/150355
*/
if (num_threads < 0)
num_threads = 4;
if (num_threads > fs->group_desc_count)
num_threads = fs->group_desc_count;
average_group = fs->group_desc_count / num_threads;
if (ext2fs_has_feature_flex_bg(fs->super)) {
average_group = (average_group / flexbg_size) * flexbg_size;
}
if (average_group == 0)
goto fallback;
io_channel_set_options(fs->io, "cache=off");
retval = pthread_attr_init(&attr);
if (retval)
return retval;
thread_ids = calloc(sizeof(pthread_t), num_threads);
if (!thread_ids)
return ENOMEM;
thread_infos = calloc(sizeof(struct read_bitmaps_thread_info),
num_threads);
if (!thread_infos)
goto out;
retval = read_bitmaps_range_prepare(fs, flags);
if (retval)
goto out;
// fprintf(stdout, "Multiple threads triggered to read bitmaps\n");
for (i = 0; i < num_threads; i++) {
thread_infos[i].rbt_fs = fs;
thread_infos[i].rbt_flags = flags;
thread_infos[i].rbt_mutex = &rbt_mutex;
thread_infos[i].rbt_tail_flags = 0;
if (i == 0)
thread_infos[i].rbt_grp_start = 0;
else
thread_infos[i].rbt_grp_start = average_group * i + 1;
if (i == num_threads - 1)
thread_infos[i].rbt_grp_end = fs->group_desc_count - 1;
else
thread_infos[i].rbt_grp_end = average_group * (i + 1);
retval = pthread_create(&thread_ids[i], &attr,
&read_bitmaps_thread, &thread_infos[i]);
if (retval)
break;
}
for (i = 0; i < num_threads; i++) {
if (!thread_ids[i])
break;
rc = pthread_join(thread_ids[i], NULL);
if (rc && !retval)
retval = rc;
rc = thread_infos[i].rbt_retval;
if (rc && !retval)
retval = rc;
tail_flags |= thread_infos[i].rbt_tail_flags;
}
out:
rc = pthread_attr_destroy(&attr);
if (rc && !retval)
retval = rc;
free(thread_infos);
free(thread_ids);
if (retval == 0)
retval = read_bitmaps_range_end(fs, flags, tail_flags);
if (retval)
read_bitmaps_cleanup_on_error(fs, flags);
/* XXX should save and restore cache setting */
io_channel_set_options(fs->io, "cache=on");
return retval;
fallback:
#endif /* HAVE_PTHREAD */
return read_bitmaps_range(fs, flags, 0, fs->group_desc_count - 1);
}
errcode_t ext2fs_read_inode_bitmap(ext2_filsys fs)
{
return ext2fs_rw_bitmaps(fs, EXT2FS_BITMAPS_INODE, -1);
}
errcode_t ext2fs_read_block_bitmap(ext2_filsys fs)
{
return ext2fs_rw_bitmaps(fs, EXT2FS_BITMAPS_BLOCK, -1);
}
errcode_t ext2fs_write_inode_bitmap(ext2_filsys fs)
{
return write_bitmaps(fs, 1, 0);
}
errcode_t ext2fs_write_block_bitmap (ext2_filsys fs)
{
return write_bitmaps(fs, 0, 1);
}
errcode_t ext2fs_read_bitmaps(ext2_filsys fs)
{
int flags = 0;
if (!fs->inode_map)
flags |= EXT2FS_BITMAPS_INODE;
if (!fs->block_map)
flags |= EXT2FS_BITMAPS_BLOCK;
if (flags == 0)
return 0;
return ext2fs_rw_bitmaps(fs, flags, -1);
}
errcode_t ext2fs_write_bitmaps(ext2_filsys fs)
{
int do_inode = fs->inode_map && ext2fs_test_ib_dirty(fs);
int do_block = fs->block_map && ext2fs_test_bb_dirty(fs);
if (!do_inode && !do_block)
return 0;
return write_bitmaps(fs, do_inode, do_block);
}