ref: a9389acb2918d3b47aa792011f50e49234ea59cc
dir: /lwext4/ext4.c/
/*
* Copyright (c) 2013 Grzegorz Kostka ([email protected])
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup lwext4
* @{
*/
/**
* @file ext4.h
* @brief Ext4 high level operations (file, directory, mountpoints...)
*/
#include <ext4_config.h>
#include <ext4_blockdev.h>
#include <ext4_types.h>
#include <ext4_debug.h>
#include <ext4_errno.h>
#include <ext4_fs.h>
#include <ext4_dir.h>
#include <ext4_inode.h>
#include <ext4_super.h>
#include <ext4_dir_idx.h>
#include <stdlib.h>
#include <string.h>
#include <ext4.h>
/**@brief Mount point OS dependent lock*/
#define EXT4_MP_LOCK(_m) \
do { (_m)->os_locks ? (_m)->os_locks->lock() : 0; }while(0)
/**@brief Mount point OS dependent unlock*/
#define EXT4_MP_UNLOCK(_m) \
do { (_m)->os_locks ? (_m)->os_locks->unlock() : 0; }while(0)
/**@brief Mount point descrpitor.*/
struct ext4_mountpoint {
/**@brief Mount point name (@ref ext4_mount)*/
const char *name;
/**@brief Os dependent lock/unlock functions.*/
struct ext4_lock *os_locks;
/**@brief Ext4 filesystem internals.*/
struct ext4_fs fs;
/**@brief Dynamic alocation cache flag.*/
bool cache_dynamic;
};
/**@brief Block devices descriptor.*/
struct _ext4_devices {
/**@brief Block device name (@ref ext4_device_register)*/
const char *name;
/**@brief Block device handle.*/
struct ext4_blockdev *bd;
/**@brief Block cache handle.*/
struct ext4_bcache *bc;
};
/**@brief Block devices.*/
struct _ext4_devices _bdevices[CONFIG_EXT4_BLOCKDEVS_COUNT];
/**@brief Mountpoints.*/
struct ext4_mountpoint _mp[CONFIG_EXT4_MOUNTPOINTS_COUNT];
int ext4_device_register(struct ext4_blockdev *bd, struct ext4_bcache *bc,
const char *dev_name)
{
uint32_t i;
ext4_assert(bd && dev_name);
for (i = 0; i < CONFIG_EXT4_BLOCKDEVS_COUNT; ++i) {
if(!_bdevices[i].name){
_bdevices[i].name = dev_name;
_bdevices[i].bd = bd;
_bdevices[i].bc = bc;
return EOK;
}
}
return ENOSPC;
}
/****************************************************************************/
static bool ext4_is_dots(const uint8_t *name, size_t name_size)
{
if ((name_size == 1) && (name[0] == '.'))
return true;
if ((name_size == 2) && (name[0] == '.') && (name[1] == '.'))
return true;
return false;
}
static int ext4_has_children(bool *has_children, struct ext4_inode_ref *enode)
{
struct ext4_fs *fs = enode->fs;
/* Check if node is directory */
if (!ext4_inode_is_type(&fs->sb, enode->inode,
EXT4_INODE_MODE_DIRECTORY)) {
*has_children = false;
return EOK;
}
struct ext4_directory_iterator it;
int rc = ext4_dir_iterator_init(&it, enode, 0);
if (rc != EOK)
return rc;
/* Find a non-empty directory entry */
bool found = false;
while (it.current != NULL) {
if (it.current->inode != 0) {
uint16_t name_size =
ext4_dir_entry_ll_get_name_length(&fs->sb,
it.current);
if (!ext4_is_dots(it.current->name, name_size)) {
found = true;
break;
}
}
rc = ext4_dir_iterator_next(&it);
if (rc != EOK) {
ext4_dir_iterator_fini(&it);
return rc;
}
}
rc = ext4_dir_iterator_fini(&it);
if (rc != EOK)
return rc;
*has_children = found;
return EOK;
}
static int ext4_link(struct ext4_mountpoint *mp, struct ext4_inode_ref *parent,
struct ext4_inode_ref *child, const char *name, uint32_t name_len)
{
/* Check maximum name length */
if(name_len > EXT4_DIRECTORY_FILENAME_LEN)
return EINVAL;
/* Add entry to parent directory */
int rc = ext4_dir_add_entry(parent, name, name_len,
child);
if (rc != EOK)
return rc;
/* Fill new dir -> add '.' and '..' entries */
if (ext4_inode_is_type(&mp->fs.sb, child->inode,
EXT4_INODE_MODE_DIRECTORY)) {
rc = ext4_dir_add_entry(child, ".", strlen("."),
child);
if (rc != EOK) {
ext4_dir_remove_entry(parent, name, strlen(name));
return rc;
}
rc = ext4_dir_add_entry(child, "..", strlen(".."),
parent);
if (rc != EOK) {
ext4_dir_remove_entry(parent, name, strlen(name));
ext4_dir_remove_entry(child, ".", strlen("."));
return rc;
}
#if CONFIG_DIR_INDEX_ENABLE
/* Initialize directory index if supported */
if (ext4_sb_check_feature_compatible(&mp->fs.sb,
EXT4_FEATURE_COMPAT_DIR_INDEX)) {
rc = ext4_dir_dx_init(child);
if (rc != EOK)
return rc;
ext4_inode_set_flag(child->inode,
EXT4_INODE_FLAG_INDEX);
child->dirty = true;
}
#endif
uint16_t parent_links =
ext4_inode_get_links_count(parent->inode);
parent_links++;
ext4_inode_set_links_count(parent->inode, parent_links);
parent->dirty = true;
}
uint16_t child_links =
ext4_inode_get_links_count(child->inode);
child_links++;
ext4_inode_set_links_count(child->inode, child_links);
child->dirty = true;
return EOK;
}
static int ext4_unlink(struct ext4_mountpoint *mp,
struct ext4_inode_ref *parent, struct ext4_inode_ref *child_inode_ref,
const char *name, uint32_t name_len)
{
bool has_children;
int rc = ext4_has_children(&has_children, child_inode_ref);
if (rc != EOK)
return rc;
/* Cannot unlink non-empty node */
if (has_children)
return ENOTSUP;
/* Remove entry from parent directory */
rc = ext4_dir_remove_entry(parent, name, name_len);
if (rc != EOK)
return rc;
uint32_t lnk_count =
ext4_inode_get_links_count(child_inode_ref->inode);
lnk_count--;
bool is_dir = ext4_inode_is_type(&mp->fs.sb, child_inode_ref->inode,
EXT4_INODE_MODE_DIRECTORY);
/* If directory - handle links from parent */
if ((lnk_count <= 1) && (is_dir)) {
ext4_assert(lnk_count == 1);
lnk_count--;
uint32_t parent_lnk_count = ext4_inode_get_links_count(
parent->inode);
parent_lnk_count--;
ext4_inode_set_links_count(parent->inode, parent_lnk_count);
parent->dirty = true;
}
/*
* TODO: Update timestamps of the parent
* (when we have wall-clock time).
*
* ext4_inode_set_change_inode_time(parent->inode, (uint32_t) now);
* ext4_inode_set_modification_time(parent->inode, (uint32_t) now);
* parent->dirty = true;
*/
/*
* TODO: Update timestamp for inode.
*
* ext4_inode_set_change_inode_time(child_inode_ref->inode,
* (uint32_t) now);
*/
ext4_inode_set_deletion_time(child_inode_ref->inode, 1);
ext4_inode_set_links_count(child_inode_ref->inode, lnk_count);
child_inode_ref->dirty = true;
return EOK;
}
/****************************************************************************/
int ext4_mount(const char * dev_name, char *mount_point)
{
ext4_assert(mount_point && dev_name);
int r = EOK;
int i;
uint32_t bsize;
struct ext4_blockdev *bd = 0;
struct ext4_bcache *bc = 0;
struct ext4_mountpoint *mp = 0;
if(mount_point[strlen(mount_point) - 1] != '/')
return ENOTSUP;
for (i = 0; i < CONFIG_EXT4_BLOCKDEVS_COUNT; ++i) {
if(_bdevices[i].name){
if(!strcmp(dev_name, _bdevices[i].name)){
bd = _bdevices[i].bd;
bc = _bdevices[i].bc;
break;
}
}
}
if(!bd)
return ENODEV;
for (i = 0; i < CONFIG_EXT4_MOUNTPOINTS_COUNT; ++i) {
if(!_mp[i].name){
_mp[i].name = mount_point;
mp = &_mp[i];
break;
}
}
if(!mp)
return ENOMEM;
r = ext4_block_init(bd);
if(r != EOK)
return r;
r = ext4_fs_init(&mp->fs, bd);
if(r != EOK){
ext4_block_fini(bd);
return r;
}
bsize = ext4_sb_get_block_size(&mp->fs.sb);
ext4_block_set_lb_size(bd, bsize);
mp->cache_dynamic = 0;
if(!bc){
/*Automatic block cache alloc.*/
mp->cache_dynamic = 1;
bc = malloc(sizeof(struct ext4_bcache));
r = ext4_bcache_init_dynamic(bc, CONFIG_BLOCK_DEV_CACHE_SIZE, bsize);
if(r != EOK){
free(bc);
ext4_block_fini(bd);
return r;
}
}
if(bsize != bc->itemsize)
return ENOTSUP;
/*Bind block cache to block device*/
r = ext4_block_bind_bcache(bd, bc);
if(r != EOK){
ext4_block_fini(bd);
if(mp->cache_dynamic){
ext4_bcache_fini_dynamic(bc);
free(bc);
}
return r;
}
return r;
}
int ext4_umount(char *mount_point)
{
int i;
int r = EOK;
struct ext4_mountpoint *mp = 0;
for (i = 0; i < CONFIG_EXT4_MOUNTPOINTS_COUNT; ++i) {
if(_mp[i].name){
if(!strcmp(_mp[i].name, mount_point))
mp = &_mp[i];
break;
}
}
if(!mp)
return ENODEV;
r = ext4_fs_fini(&mp->fs);
if(r != EOK)
return r;
mp->name = 0;
if(mp->cache_dynamic){
ext4_bcache_fini_dynamic(mp->fs.bdev->bc);
free(mp->fs.bdev->bc);
}
return ext4_block_fini(mp->fs.bdev);
}
int ext4_mount_point_stats(const char *mount_point,
struct ext4_mount_stats *stats)
{
uint32_t i;
struct ext4_mountpoint *mp = 0;
for (i = 0; i < CONFIG_EXT4_MOUNTPOINTS_COUNT; ++i) {
if(_mp[i].name){
if(!strcmp(_mp[i].name, mount_point))
mp = &_mp[i];
break;
}
}
if(!mp)
return ENOENT;
EXT4_MP_LOCK(mp);
stats->inodes_count = ext4_get32(&mp->fs.sb, inodes_count);
stats->free_inodes_count = ext4_get32(&mp->fs.sb, free_inodes_count);
stats->blocks_count = ext4_sb_get_blocks_cnt(&mp->fs.sb);
stats->free_blocks_count = ext4_sb_get_free_blocks_cnt(&mp->fs.sb);
stats->block_size = ext4_sb_get_block_size(&mp->fs.sb);
stats->block_group_count = ext4_block_group_cnt(&mp->fs.sb);
stats->blocks_per_group = ext4_get32(&mp->fs.sb, blocks_per_group);
stats->inodes_per_group = ext4_get32(&mp->fs.sb, inodes_per_group);
memcpy(stats->volume_name, mp->fs.sb.volume_name, 16);
EXT4_MP_UNLOCK(mp);
return EOK;
}
/********************************FILE OPERATIONS*****************************/
static struct ext4_mountpoint* ext4_get_mount(const char *path)
{
int i;
for (i = 0; i < CONFIG_EXT4_MOUNTPOINTS_COUNT; ++i) {
if(_mp[i].name){
if(!strncmp(_mp[i].name, path, strlen(_mp[i].name)))
return &_mp[i];
}
}
return 0;
}
static int ext4_path_check(const char *path, bool* is_goal)
{
int i;
for (i = 0; i < EXT4_DIRECTORY_FILENAME_LEN; ++i) {
if(path[i] == '/'){
*is_goal = false;
return i;
}
if(path[i] == 0){
*is_goal = true;
return i;
}
}
return 0;
}
static bool ext4_parse_flags(const char *flags, uint32_t *file_flags)
{
if(!flags)
return false;
if(!strcmp(flags, "r") || !strcmp(flags, "rb")){
*file_flags = O_RDONLY;
return true;
}
if(!strcmp(flags, "w") || !strcmp(flags, "wb")){
*file_flags = O_WRONLY | O_CREAT | O_TRUNC;
return true;
}
if(!strcmp(flags, "a") || !strcmp(flags, "ab")){
*file_flags = O_WRONLY | O_CREAT | O_APPEND;
return true;
}
if(!strcmp(flags, "r+") || !strcmp(flags, "rb+") || !strcmp(flags, "r+b")){
*file_flags = O_RDWR;
return true;
}
if(!strcmp(flags, "w+") || !strcmp(flags, "wb+") || !strcmp(flags, "w+b")){
*file_flags = O_RDWR | O_CREAT | O_TRUNC;
return true;
}
if(!strcmp(flags, "a+") || !strcmp(flags, "ab+") || !strcmp(flags, "a+b")){
*file_flags = O_RDWR | O_CREAT | O_APPEND;
return true;
}
return false;
}
/****************************************************************************/
static int ext4_generic_open (ext4_file *f, const char *path,
const char *flags, bool file_expect, uint32_t *parent_inode, uint32_t *name_off)
{
struct ext4_mountpoint *mp = ext4_get_mount(path);
struct ext4_directory_search_result result;
struct ext4_inode_ref ref;
bool is_goal = false;
uint8_t inode_type = EXT4_DIRECTORY_FILETYPE_DIR;
int r = ENOENT;
uint32_t next_inode;
f->mp = 0;
if(!mp)
return ENOENT;
if(ext4_parse_flags(flags, &f->flags) == false)
return EINVAL;
/*Skip mount point*/
path += strlen(mp->name);
if(name_off)
*name_off = strlen(mp->name);
/*Load root*/
r = ext4_fs_get_inode_ref(&mp->fs, EXT4_INODE_ROOT_INDEX, &ref);
if(r != EOK)
return r;
if(parent_inode)
*parent_inode = ref.index;
int len = ext4_path_check(path, &is_goal);
while(1){
len = ext4_path_check(path, &is_goal);
if(!len){
/*If root open was request.*/
if(is_goal && !file_expect)
break;
r = ENOENT;
break;
}
r = ext4_dir_find_entry(&result, &ref, path, len);
if(r != EOK){
if(r != ENOENT)
break;
if(!(f->flags & O_CREAT))
break;
/*O_CREAT allows create new entry*/
struct ext4_inode_ref child_ref;
r = ext4_fs_alloc_inode(&mp->fs, &child_ref, is_goal ? !file_expect : true);
if(r != EOK)
break;
/*Destroy last result*/
ext4_dir_destroy_result(&ref, &result);
/*Link with root dir.*/
r = ext4_link(mp, &ref, &child_ref, path, len);
if(r != EOK){
/*Fali. Free new inode.*/
ext4_fs_free_inode(&child_ref);
/*We do not want to write new inode.
But block has to be released.*/
child_ref.dirty = false;
ext4_fs_put_inode_ref(&child_ref);
break;
}
ext4_fs_put_inode_ref(&child_ref);
continue;
}
if(parent_inode)
*parent_inode = ref.index;
next_inode = result.dentry->inode;
inode_type = ext4_dir_entry_ll_get_inode_type(&mp->fs.sb, result.dentry);
r = ext4_dir_destroy_result(&ref, &result);
if(r != EOK)
break;
/*If expected file error*/
if((inode_type == EXT4_DIRECTORY_FILETYPE_REG_FILE)
&& !file_expect && is_goal){
r = ENOENT;
break;
}
/*If expected directory error*/
if((inode_type == EXT4_DIRECTORY_FILETYPE_DIR)
&& file_expect && is_goal){
r = ENOENT;
break;
}
r = ext4_fs_put_inode_ref(&ref);
if(r != EOK)
break;
r = ext4_fs_get_inode_ref(&mp->fs, next_inode, &ref);
if(r != EOK)
break;
if(is_goal)
break;
path += len + 1;
if(name_off)
*name_off += len + 1;
};
if(r != EOK){
ext4_fs_put_inode_ref(&ref);
return r;
}
if(is_goal){
if((f->flags & O_TRUNC) &&
(inode_type == EXT4_DIRECTORY_FILETYPE_REG_FILE)){
/*Turncate.*/
ext4_block_delay_cache_flush(mp->fs.bdev, 1);
/*Truncate may be IO heavy.
Do it with delayed cache flush mode.*/
r = ext4_fs_truncate_inode(&ref, 0);
ext4_block_delay_cache_flush(mp->fs.bdev, 0);
if(r != EOK){
ext4_fs_put_inode_ref(&ref);
return r;
}
}
f->mp = mp;
f->fsize = ext4_inode_get_size(&f->mp->fs.sb, ref.inode);
f->inode = ref.index;
f->fpos = 0;
if(f->flags & O_APPEND)
f->fpos = f->fsize;
}
r = ext4_fs_put_inode_ref(&ref);
return r;
}
/****************************************************************************/
int ext4_fremove(const char *path)
{
ext4_file f;
uint32_t parent_inode;
uint32_t name_off;
int r;
int len;
bool is_goal;
struct ext4_mountpoint *mp = ext4_get_mount(path);
struct ext4_inode_ref child;
struct ext4_inode_ref parent;
if(!mp)
return ENOENT;
EXT4_MP_LOCK(mp);
r = ext4_generic_open(&f, path, "r", true, &parent_inode, &name_off);
if(r != EOK){
EXT4_MP_UNLOCK(mp);
return r;
}
/*Load parent*/
r = ext4_fs_get_inode_ref(&mp->fs, parent_inode, &parent);
if(r != EOK){
EXT4_MP_UNLOCK(mp);
return r;
}
/*We have file to delete. Load it.*/
r = ext4_fs_get_inode_ref(&mp->fs, f.inode, &child);
if(r != EOK){
ext4_fs_put_inode_ref(&parent);
EXT4_MP_UNLOCK(mp);
return r;
}
/*Turncate.*/
ext4_block_delay_cache_flush(mp->fs.bdev, 1);
/*Truncate may be IO heavy. Do it with delayed cache flush mode.*/
r = ext4_fs_truncate_inode(&child, 0);
ext4_block_delay_cache_flush(mp->fs.bdev, 0);
if(r != EOK)
goto Finish;
/*Set path*/
path += name_off;
len = ext4_path_check(path, &is_goal);
/*Unlink from parent.*/
r = ext4_unlink(mp, &parent, &child, path, len);
if(r != EOK)
goto Finish;
r = ext4_fs_free_inode(&child);
if(r != EOK)
goto Finish;
Finish:
ext4_fs_put_inode_ref(&child);
ext4_fs_put_inode_ref(&parent);
EXT4_MP_UNLOCK(mp);
return r;
}
int ext4_fopen (ext4_file *f, const char *path, const char *flags)
{
struct ext4_mountpoint *mp = ext4_get_mount(path);
int r;
if(!mp)
return ENOENT;
EXT4_MP_LOCK(mp);
r = ext4_generic_open(f, path, flags, true, 0, 0);
EXT4_MP_UNLOCK(mp);
return r;
}
int ext4_fclose(ext4_file *f)
{
ext4_assert(f && f->mp);
f->mp = 0;
f->flags = 0;
f->inode = 0;
f->fpos = f->fsize = 0;
return EOK;
}
int ext4_fread(ext4_file *f, void *buf, uint32_t size, uint32_t *rcnt)
{
int r = EOK;
uint32_t u;
uint32_t fblock;
uint32_t fblock_start;
uint32_t fblock_cnt;
struct ext4_block b;
uint8_t *u8_buf = buf;
struct ext4_inode_ref ref;
uint32_t sblock;
uint32_t sblock_end;
uint32_t block_size;
ext4_assert(f && f->mp);
if(f->flags & O_WRONLY)
return EPERM;
if(!size)
return EOK;
EXT4_MP_LOCK(f->mp);
if(rcnt)
*rcnt = 0;
r = ext4_fs_get_inode_ref(&f->mp->fs, f->inode, &ref);
if(r != EOK){
EXT4_MP_UNLOCK(f->mp);
return r;
}
/*Sync file size*/
f->fsize = ext4_inode_get_size(&f->mp->fs.sb, ref.inode);
block_size = ext4_sb_get_block_size(&f->mp->fs.sb);
size = size > (f->fsize - f->fpos) ? (f->fsize - f->fpos) : size;
sblock = (f->fpos) / block_size;
sblock_end = (f->fpos + size) / block_size;
u = (f->fpos) % block_size;
if(u){
uint32_t ll = size > (block_size - u) ? (block_size - u) : size;
r = ext4_fs_get_inode_data_block_index(&ref, sblock, &fblock);
if(r != EOK)
goto Finish;
r = ext4_block_get(f->mp->fs.bdev, &b, fblock);
if(r != EOK)
goto Finish;
memcpy(u8_buf, b.data + u, ll);
r = ext4_block_set(f->mp->fs.bdev, &b);
if(r != EOK)
goto Finish;
u8_buf += ll;
size -= ll;
f->fpos += ll;
if(rcnt)
*rcnt += ll;
sblock++;
}
fblock_start = 0;
fblock_cnt = 0;
while(size >= block_size){
while(sblock < sblock_end){
r = ext4_fs_get_inode_data_block_index(&ref, sblock, &fblock);
if(r != EOK)
goto Finish;
sblock++;
if(!fblock_start){
fblock_start = fblock;
}
if((fblock_start + fblock_cnt) != fblock)
break;
fblock_cnt++;
}
r = ext4_blocks_get_direct(f->mp->fs.bdev, u8_buf, fblock_start, fblock_cnt);
if(r != EOK)
goto Finish;
size -= block_size * fblock_cnt;
u8_buf += block_size * fblock_cnt;
f->fpos += block_size * fblock_cnt;
if(rcnt)
*rcnt += block_size * fblock_cnt;
fblock_start = fblock;
fblock_cnt = 1;
}
if(size){
r = ext4_fs_get_inode_data_block_index(&ref, sblock, &fblock);
if(r != EOK)
goto Finish;
r = ext4_block_get(f->mp->fs.bdev, &b, fblock);
if(r != EOK)
goto Finish;
memcpy(u8_buf, b.data , size);
r = ext4_block_set(f->mp->fs.bdev, &b);
if(r != EOK)
goto Finish;
f->fpos += size;
if(rcnt)
*rcnt += size;
}
Finish:
ext4_fs_put_inode_ref(&ref);
EXT4_MP_UNLOCK(f->mp);
return r;
}
int ext4_fwrite(ext4_file *f, void *buf, uint32_t size, uint32_t *wcnt)
{
int r = EOK;
uint32_t u;
uint32_t fblock;
struct ext4_block b;
uint8_t *u8_buf = buf;
struct ext4_inode_ref ref;
uint32_t sblock;
uint32_t sblock_end;
uint32_t file_blocks;
uint32_t block_size;
uint32_t fblock_start;
uint32_t fblock_cnt;
ext4_assert(f && f->mp);
if(f->flags & O_RDONLY)
return EPERM;
if(!size)
return EOK;
EXT4_MP_LOCK(f->mp);
if(wcnt)
*wcnt = 0;
r = ext4_fs_get_inode_ref(&f->mp->fs, f->inode, &ref);
if(r != EOK){
EXT4_MP_UNLOCK(f->mp);
return r;
}
/*Sync file size*/
f->fsize = ext4_inode_get_size(&f->mp->fs.sb, ref.inode);
block_size = ext4_sb_get_block_size(&f->mp->fs.sb);
sblock_end = (f->fpos + size) > f->fsize ? (f->fpos + size) : f->fsize;
sblock_end /= block_size;
file_blocks = (f->fsize / block_size);
if(f->fsize % block_size)
file_blocks++;
sblock = (f->fpos) / block_size;
u = (f->fpos) % block_size;
if(u){
uint32_t ll = size > (block_size - u) ? (block_size - u) : size;
r = ext4_fs_get_inode_data_block_index(&ref, sblock, &fblock);
if(r != EOK)
goto Finish;
r = ext4_block_get(f->mp->fs.bdev, &b, fblock);
if(r != EOK)
goto Finish;
memcpy(b.data + u, u8_buf, ll);
b.dirty = true;
r = ext4_block_set(f->mp->fs.bdev, &b);
if(r != EOK)
goto Finish;
u8_buf += ll;
size -= ll;
f->fpos += ll;
if(wcnt)
*wcnt += ll;
sblock++;
}
/*Start delay cache flush mode.*/
r = ext4_block_delay_cache_flush(f->mp->fs.bdev, 1);
if(r != EOK)
goto Finish;
fblock_start = 0;
fblock_cnt = 0;
while(size >= block_size){
while(sblock < sblock_end){
if(sblock < file_blocks){
r = ext4_fs_get_inode_data_block_index(&ref, sblock, &fblock);
if(r != EOK)
break;
}
else {
r = ext4_fs_append_inode_block(&ref, &fblock, &sblock);
if(r != EOK)
break;
}
sblock++;
if(!fblock_start){
fblock_start = fblock;
}
if((fblock_start + fblock_cnt) != fblock)
break;
fblock_cnt++;
}
r = ext4_blocks_set_direct(f->mp->fs.bdev, u8_buf, fblock_start, fblock_cnt);
if(r != EOK)
break;
size -= block_size * fblock_cnt;
u8_buf += block_size * fblock_cnt;
f->fpos += block_size * fblock_cnt;
if(wcnt)
*wcnt += block_size * fblock_cnt;
fblock_start = fblock;
fblock_cnt = 1;
}
/*Stop delay cache flush mode*/
ext4_block_delay_cache_flush(f->mp->fs.bdev, 0);
if(r != EOK)
goto Finish;
if(size){
if(sblock < file_blocks){
r = ext4_fs_get_inode_data_block_index(&ref, sblock, &fblock);
if(r != EOK)
goto Finish;
}
else {
r = ext4_fs_append_inode_block(&ref, &fblock, &sblock);
if(r != EOK)
goto Finish;
}
r = ext4_block_get(f->mp->fs.bdev, &b, fblock);
if(r != EOK)
goto Finish;
memcpy(b.data, u8_buf , size);
b.dirty = true;
r = ext4_block_set(f->mp->fs.bdev, &b);
if(r != EOK)
goto Finish;
f->fpos += size;
if(wcnt)
*wcnt += size;
}
if(f->fpos > f->fsize){
f->fsize = f->fpos;
ext4_inode_set_size(ref.inode, f->fsize);
ref.dirty = true;
}
Finish:
ext4_fs_put_inode_ref(&ref);
EXT4_MP_UNLOCK(f->mp);
return r;
}
int ext4_fseek(ext4_file *f, uint64_t offset, uint32_t origin)
{
switch(origin){
case SEEK_SET:
if(offset > f->fsize)
return EINVAL;
f->fpos = offset;
return EOK;
case SEEK_CUR:
if((offset + f->fpos) > f->fsize)
return EINVAL;
f->fpos += offset;
return EOK;
case SEEK_END:
if(offset > f->fsize)
return EINVAL;
f->fpos = f->fsize - offset;
return EOK;
}
return EINVAL;
}
uint64_t ext4_ftell (ext4_file *f)
{
return f->fpos;
}
uint64_t ext4_fsize (ext4_file *f)
{
return f->fsize;
}
/*********************************DIRECTORY OPERATION************************/
int ext4_dir_rm(const char *path)
{
int r;
int len;
ext4_file f;
struct ext4_mountpoint *mp = ext4_get_mount(path);
struct ext4_inode_ref current;
struct ext4_inode_ref child;
struct ext4_directory_iterator it;
uint32_t name_off;
uint32_t inode_up;
uint32_t inode_current;
uint32_t depth = 1;
bool has_children;
bool is_goal;
bool dir_end;
if(!mp)
return ENOENT;
EXT4_MP_LOCK(mp);
/*Check if exist.*/
r = ext4_generic_open(&f, path, "r", false, &inode_up, &name_off);
if(r != EOK){
EXT4_MP_UNLOCK(mp);
return r;
}
path += name_off;
len = ext4_path_check(path, &is_goal);
inode_current = f.inode;
dir_end = false;
do {
/*Load directory node.*/
r = ext4_fs_get_inode_ref(&f.mp->fs, inode_current, ¤t);
if(r != EOK){
break;
}
/*Initialize iterator.*/
r = ext4_dir_iterator_init(&it, ¤t, 0);
if(r != EOK){
ext4_fs_put_inode_ref(¤t);
break;
}
while(r == EOK){
if(!it.current){
dir_end = true;
break;
}
/*Get up directory inode when ".." entry*/
if((it.current->name_length == 2) &&
ext4_is_dots(it.current->name, it.current->name_length)){
inode_up = it.current->inode;
}
/*If directory or file entry, but not "." ".." entry*/
if(!ext4_is_dots(it.current->name, it.current->name_length)){
/*Get child inode reference do unlink directory/file.*/
r = ext4_fs_get_inode_ref(&f.mp->fs, it.current->inode, &child);
if(r != EOK)
break;
/*If directory with no leaf children*/
r = ext4_has_children(&has_children, &child);
if(r != EOK){
ext4_fs_put_inode_ref(&child);
break;
}
if(has_children){
/*Has directory children. Go into this tirectory.*/
inode_up = inode_current;
inode_current = it.current->inode;
depth++;
ext4_fs_put_inode_ref(&child);
break;
}
/*Directory is empty. Truncate it.*/
r = ext4_fs_truncate_inode(&child, 0);
if(r != EOK){
ext4_fs_put_inode_ref(&child);
break;
}
/*No children in child directory or file. Just unlink.*/
r = ext4_unlink(f.mp, ¤t, &child,
(char *)it.current->name, it.current->name_length);
if(r != EOK){
ext4_fs_put_inode_ref(&child);
break;
}
r = ext4_fs_free_inode(&child);
if(r != EOK){
ext4_fs_put_inode_ref(&child);
break;
}
r = ext4_fs_put_inode_ref(&child);
if(r != EOK)
break;
}
r = ext4_dir_iterator_next(&it);
}
if(dir_end){
/*Directory iterator reached last entry*/
ext4_has_children(&has_children, ¤t);
if(!has_children){
inode_current = inode_up;
if(depth)
depth--;
}
/*Last unlink*/
if(!depth){
/*Load parent.*/
struct ext4_inode_ref parent;
r = ext4_fs_get_inode_ref(&f.mp->fs, inode_up, &parent);
if(r != EOK)
goto End;
r = ext4_fs_truncate_inode(¤t, 0);
if(r != EOK){
ext4_fs_put_inode_ref(&parent);
goto End;
}
/* In this place all directories should be unlinked.
* Last unlink from root of current directory*/
r = ext4_unlink(f.mp, &parent, ¤t, (char *)path, len);
if(r != EOK){
ext4_fs_put_inode_ref(&parent);
goto End;
}
r = ext4_fs_free_inode(¤t);
if(r != EOK){
ext4_fs_put_inode_ref(&parent);
goto End;
}
r = ext4_fs_put_inode_ref(&parent);
if(r != EOK)
goto End;
}
}
End:
ext4_dir_iterator_fini(&it);
ext4_fs_put_inode_ref(¤t);
dir_end = false;
/*When something goes wrong. End loop.*/
if(r != EOK)
break;
}while(depth);
EXT4_MP_UNLOCK(mp);
return r;
}
int ext4_dir_mk(const char *path)
{
int r;
ext4_file f;
struct ext4_mountpoint *mp = ext4_get_mount(path);
if(!mp)
return ENOENT;
EXT4_MP_LOCK(mp);
/*Check if exist.*/
r = ext4_generic_open(&f, path, "r", false, 0, 0);
if(r == EOK){
/*Directory already created*/
EXT4_MP_UNLOCK(mp);
return r;
}
/*Create new dir*/
r = ext4_generic_open(&f, path, "w", false, 0, 0);
if(r != EOK){
EXT4_MP_UNLOCK(mp);
return r;
}
EXT4_MP_UNLOCK(mp);
return r;
}
int ext4_dir_open (ext4_dir *d, const char *path)
{
struct ext4_mountpoint *mp = ext4_get_mount(path);
int r;
if(!mp)
return ENOENT;
EXT4_MP_LOCK(mp);
r = ext4_generic_open(&d->f, path, "r", false, 0, 0);
EXT4_MP_UNLOCK(mp);
return r;
}
int ext4_dir_close(ext4_dir *d)
{
return ext4_fclose(&d->f);
}
ext4_direntry* ext4_dir_entry_get(ext4_dir *d, uint32_t id)
{
int r;
uint32_t i;
ext4_direntry *de = 0;
struct ext4_inode_ref dir;
struct ext4_directory_iterator it;
EXT4_MP_LOCK(d->f.mp);
r = ext4_fs_get_inode_ref(&d->f.mp->fs, d->f.inode, &dir);
if(r != EOK){
goto Finish;
}
r = ext4_dir_iterator_init(&it, &dir, 0);
if(r != EOK){
ext4_fs_put_inode_ref(&dir);
goto Finish;
}
i = 0;
while(r == EOK){
if(!it.current)
break;
if(i == id){
memcpy(&d->de, it.current, sizeof(ext4_direntry));
de = &d->de;
break;
}
i++;
r = ext4_dir_iterator_next(&it);
}
ext4_dir_iterator_fini(&it);
ext4_fs_put_inode_ref(&dir);
Finish:
EXT4_MP_UNLOCK(d->f.mp);
return de;
}
/**
* @}
*/