CfgUSBLoader/lib/libext2fs/source/ext2file.c

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/**
* ext2file.c - devoptab file routines for EXT2-based devices.
*
* Copyright (c) 2006 Michael "Chishm" Chisholm
* Copyright (c) 2009 Rhys "Shareese" Koedijk
* Copyright (c) 2010 Dimok
*
* This program/include file is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program/include file is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <stdlib.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include "ext2_internal.h"
#include "ext2file.h"
#define STATE(x) ((ext2_file_state*)x)
void ext2CloseFile (ext2_file_state *file)
{
// Sanity check
if (!file || !file->vd)
return;
ext2fs_file_close(file->fd);
// Sync the file (and its attributes) to disc
if(file->write)
{
// Read in node changes before writing them
ext2fs_read_inode(file->vd->fs, file->ni->ino, &file->ni->ni);
ext2UpdateTimes(file->vd, file->ni, EXT2_UPDATE_ACTIME);
}
if (file->read)
ext2UpdateTimes(file->vd, file->ni, EXT2_UPDATE_ATIME);
ext2Sync(file->vd, file->ni);
// Close the file (if open)
if (file->ni)
ext2CloseEntry(file->vd, file->ni);
// Reset the file state
file->ni = NULL;
file->fd = NULL;
file->flags = 0;
file->read = false;
file->write = false;
file->append = false;
return;
}
int ext2_open_r (struct _reent *r, void *fileStruct, const char *path, int flags, int mode)
{
ext2_log_trace("fileStruct %p, path %s, flags %i, mode %i\n", fileStruct, path, flags, mode);
ext2_file_state* file = STATE(fileStruct);
// Get the volume descriptor for this path
file->vd = ext2GetVolume(path);
if (!file->vd) {
r->_errno = ENODEV;
return -1;
}
// Lock
ext2Lock(file->vd);
// Determine which mode the file is opened for
file->flags = flags;
if ((flags & 0x03) == O_RDONLY) {
file->read = true;
file->write = false;
file->append = false;
} else if ((flags & 0x03) == O_WRONLY) {
file->read = false;
file->write = true;
file->append = (flags & O_APPEND);
} else if ((flags & 0x03) == O_RDWR) {
file->read = true;
file->write = true;
file->append = (flags & O_APPEND);
} else {
r->_errno = EACCES;
ext2Unlock(file->vd);
return -1;
}
// Try and find the file and (if found) ensure that it is not a directory
file->ni = ext2OpenEntry(file->vd, path);
if (file->ni && LINUX_S_ISDIR(file->ni->ni.i_mode))
{
ext2CloseEntry(file->vd, file->ni);
ext2Unlock(file->vd);
r->_errno = EISDIR;
return -1;
}
// Are we creating this file?
if ((flags & O_CREAT) && !file->ni)
// Create the file
file->ni = ext2Create(file->vd, path, S_IFREG, NULL);
// Sanity check, the file should be open by now
if (!file->ni) {
ext2Unlock(file->vd);
r->_errno = ENOENT;
return -1;
}
// Make sure we aren't trying to write to a read-only file
if (!(file->vd->fs->flags & EXT2_FLAG_RW) && file->write)
{
ext2CloseEntry(file->vd, file->ni);
ext2Unlock(file->vd);
r->_errno = EROFS;
return -1;
}
errcode_t err = ext2fs_file_open2(file->vd->fs, file->ni->ino, &file->ni->ni,
file->write ? EXT2_FLAG_RW : 0, &file->fd);
if(err != 0)
{
ext2CloseEntry(file->vd, file->ni);
ext2Unlock(file->vd);
r->_errno = ENOENT;
return -1;
}
// Truncate the file if requested
if ((flags & O_TRUNC) && file->write) {
if (ext2fs_file_set_size2(file->fd, 0) != 0) {
ext2CloseEntry(file->vd, file->ni);
ext2Unlock(file->vd);
r->_errno = errno;
return -1;
}
file->ni->ni.i_size = file->ni->ni.i_size_high = 0;
}
// Set the files current position
ext2fs_file_llseek(file->fd, file->append ? EXT2_I_SIZE(&file->ni->ni) : 0, SEEK_SET, 0);
ext2_log_trace("file->len %lld\n", EXT2_I_SIZE(&file->ni->ni));
// Update file times
ext2UpdateTimes(file->vd, file->ni, EXT2_UPDATE_ATIME);
// Insert the file into the double-linked FILO list of open files
if (file->vd->firstOpenFile) {
file->nextOpenFile = file->vd->firstOpenFile;
file->vd->firstOpenFile->prevOpenFile = file;
} else {
file->nextOpenFile = NULL;
}
file->prevOpenFile = NULL;
file->vd->firstOpenFile = file;
file->vd->openFileCount++;
// Sync access time
ext2Sync(file->vd, file->ni);
// Unlock
ext2Unlock(file->vd);
return (int)fileStruct;
}
int ext2_close_r (struct _reent *r, int fd)
{
ext2_log_trace("fd %p\n", (void *) fd);
ext2_file_state* file = STATE(fd);
// Sanity check
if (!file || !file->vd) {
r->_errno = EBADF;
return -1;
}
// Lock
ext2Lock(file->vd);
// Close the file
ext2CloseFile(file);
// Remove the file from the double-linked FILO list of open files
file->vd->openFileCount--;
if (file->nextOpenFile)
file->nextOpenFile->prevOpenFile = file->prevOpenFile;
if (file->prevOpenFile)
file->prevOpenFile->nextOpenFile = file->nextOpenFile;
else
file->vd->firstOpenFile = file->nextOpenFile;
// Unlock
ext2Unlock(file->vd);
return 0;
}
ssize_t ext2_write_r (struct _reent *r, int fd, const char *ptr, size_t len)
{
ext2_log_trace("fd %p, ptr %p, len %i\n", (void *) fd, ptr, len);
ext2_file_state* file = STATE(fd);
// Sanity check
if (!file || !file->vd || !file->fd) {
r->_errno = EINVAL;
return -1;
}
// Short circuit cases where we don't actually have to do anything
if (!ptr || len <= 0) {
return 0;
}
// Check that we are allowed to write to this file
if (!file->write) {
r->_errno = EACCES;
return -1;
}
// Lock
ext2Lock(file->vd);
u32 writen = 0;
// Write to the files data atrribute
errcode_t err = ext2fs_file_write(file->fd, ptr, len, &writen);
if (writen <= 0 || err) {
ext2Unlock(file->vd);
r->_errno = errno;
return (err ? err : -1);
}
// Unlock
ext2Unlock(file->vd);
return (writen == 0 ? -1 : writen);
}
ssize_t ext2_read_r (struct _reent *r, int fd, char *ptr, size_t len)
{
ext2_log_trace("fd %p, ptr %p, len %i\n", (void *) fd, ptr, len);
ext2_file_state* file = STATE(fd);
// Sanity check
if (!file || !file->vd || !file->fd) {
r->_errno = EINVAL;
return -1;
}
// Short circuit cases where we don't actually have to do anything
if (!ptr || len <= 0) {
return 0;
}
// Lock
ext2Lock(file->vd);
// Check that we are allowed to read from this file
if (!file->read) {
ext2Unlock(file->vd);
r->_errno = EACCES;
return -1;
}
u32 read = 0;
errcode_t err = 0;
// Read from the files data attribute
err = ext2fs_file_read(file->fd, ptr, len, &read);
if (err || read <= 0 || read > len) {
ext2Unlock(file->vd);
r->_errno = errno;
return err ? err : -1;
}
// Unlock
ext2Unlock(file->vd);
return (read == 0) ? -1 : read;
}
off_t ext2_seek_r (struct _reent *r, int fd, off_t pos, int dir)
{
ext2_log_trace("fd %p, pos %lli, dir %i\n", (void *) fd, pos, dir);
ext2_file_state* file = STATE(fd);
// Sanity check
if (!file || !file->fd) {
r->_errno = EINVAL;
return -1;
}
u64 pos_loaded = 0;
ext2fs_file_llseek(file->fd, pos, dir, &pos_loaded);
return (off_t) pos_loaded;
}
int ext2_fstat_r (struct _reent *r, int fd, struct stat *st)
{
ext2_log_trace("fd %p\n", (void *) fd);
ext2_file_state* file = STATE(fd);
int ret = 0;
// Sanity check
if (!file || !file->vd || !file->ni || !file->fd) {
r->_errno = EINVAL;
return -1;
}
// Short circuit cases were we don't actually have to do anything
if (!st)
return 0;
// Get the file stats
ret = ext2Stat(file->vd, file->ni, st);
if (ret)
r->_errno = errno;
return ret;
}
int ext2_ftruncate_r (struct _reent *r, int fd, off_t len)
{
ext2_log_trace("fd %p, len %Li\n", (void *) fd, len);
ext2_file_state* file = STATE(fd);
errcode_t err = 0;
// Sanity check
if (!file || !file->vd || !file->ni || !file->fd) {
r->_errno = EINVAL;
return -1;
}
// Lock
ext2Lock(file->vd);
// Check that we are allowed to write to this file
if (!file->write) {
ext2Unlock(file->vd);
r->_errno = EACCES;
return -1;
}
err = ext2fs_file_set_size2(file->fd, len);
// Sync the file (and its attributes) to disc
if(!err)
ext2Sync(file->vd, file->ni);
// update times
ext2UpdateTimes(file->vd, file->ni, EXT2_UPDATE_AMTIME);
// Unlock
ext2Unlock(file->vd);
return err;
}
int ext2_fsync_r (struct _reent *r, int fd)
{
ext2_log_trace("fd %p\n", (void *) fd);
ext2_file_state* file = STATE(fd);
int ret = 0;
// Sanity check
if (!file || !file->fd) {
r->_errno = EINVAL;
return -1;
}
// Lock
ext2Lock(file->vd);
// Sync the file (and its attributes) to disc
ret = ext2fs_file_flush(file->fd);
if (ret)
r->_errno = ret;
// Unlock
ext2Unlock(file->vd);
return ret;
}