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rockbox/firmware/common/file.c
Thomas Martitz af7aaae478 Dircache: Don't expose struct dircache_entry and pointers into the cache, use IDs instead. 
Only integer IDs are exposed from dircache with this. This way the cache is isolated from other modules.
This is needed for my buflib gsoc project.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30038 a1c6a512-1295-4272-9138-f99709370657
2011-06-20 20:12:42 +00:00

836 lines
21 KiB
C
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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2002 by Björn Stenberg
*
* This program 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include <string.h>
#include <errno.h>
#include <stdbool.h>
#include "file.h"
#include "fat.h"
#include "dir_uncached.h"
#include "debug.h"
#include "dircache.h"
#include "filefuncs.h"
#include "system.h"
/*
These functions provide a roughly POSIX-compatible file IO API.
Since the fat32 driver only manages sectors, we maintain a one-sector
cache for each open file. This way we can provide byte access without
having to re-read the sector each time.
The penalty is the RAM used for the cache and slightly more complex code.
*/
struct filedesc {
unsigned char cache[SECTOR_SIZE] CACHEALIGN_ATTR;
int cacheoffset; /* invariant: 0 <= cacheoffset <= SECTOR_SIZE */
long fileoffset;
long size;
int attr;
struct fat_file fatfile;
bool busy;
bool write;
bool dirty;
bool trunc;
} CACHEALIGN_ATTR;
static struct filedesc openfiles[MAX_OPEN_FILES] CACHEALIGN_ATTR;
static int flush_cache(int fd);
int file_creat(const char *pathname)
{
return open(pathname, O_WRONLY|O_CREAT|O_TRUNC, 0666);
}
static int open_internal(const char* pathname, int flags, bool use_cache)
{
DIR_UNCACHED* dir;
struct dirent_uncached* entry;
int fd;
int pathnamesize = strlen(pathname) + 1;
char pathnamecopy[pathnamesize];
char* name;
struct filedesc* file = NULL;
int rc;
#ifndef HAVE_DIRCACHE
(void)use_cache;
#endif
LDEBUGF("open(\"%s\",%d)\n",pathname,flags);
if ( pathname[0] != '/' ) {
DEBUGF("'%s' is not an absolute path.\n",pathname);
DEBUGF("Only absolute pathnames supported at the moment\n");
errno = EINVAL;
return -1;
}
/* find a free file descriptor */
for ( fd=0; fd<MAX_OPEN_FILES; fd++ )
if ( !openfiles[fd].busy )
break;
if ( fd == MAX_OPEN_FILES ) {
DEBUGF("Too many files open\n");
errno = EMFILE;
return -2;
}
file = &openfiles[fd];
memset(file, 0, sizeof(struct filedesc));
if (flags & (O_RDWR | O_WRONLY)) {
file->write = true;
if (flags & O_TRUNC)
file->trunc = true;
}
file->busy = true;
#ifdef HAVE_DIRCACHE
if (dircache_is_enabled() && !file->write && use_cache)
{
# ifdef HAVE_MULTIVOLUME
int volume = strip_volume(pathname, pathnamecopy);
# endif
int ce = dircache_get_entry_id(pathname);
if (ce < 0)
{
errno = ENOENT;
file->busy = false;
return -7;
}
long startcluster = _dircache_get_entry_startcluster(ce);
fat_open(IF_MV2(volume,)
startcluster,
&(file->fatfile),
NULL);
struct dirinfo *info = _dircache_get_entry_dirinfo(ce);
file->size = info->size;
file->attr = info->attribute;
file->cacheoffset = -1;
file->fileoffset = 0;
return fd;
}
#endif
strlcpy(pathnamecopy, pathname, pathnamesize);
/* locate filename */
name=strrchr(pathnamecopy+1,'/');
if ( name ) {
*name = 0;
dir = opendir_uncached(pathnamecopy);
*name = '/';
name++;
}
else {
dir = opendir_uncached("/");
name = pathnamecopy+1;
}
if (!dir) {
DEBUGF("Failed opening dir\n");
errno = EIO;
file->busy = false;
return -4;
}
if(name[0] == 0) {
DEBUGF("Empty file name\n");
errno = EINVAL;
file->busy = false;
closedir_uncached(dir);
return -5;
}
/* scan dir for name */
while ((entry = readdir_uncached(dir))) {
if ( !strcasecmp(name, entry->d_name) ) {
fat_open(IF_MV2(dir->fatdir.file.volume,)
entry->startcluster,
&(file->fatfile),
&(dir->fatdir));
file->size = file->trunc ? 0 : entry->info.size;
file->attr = entry->info.attribute;
break;
}
}
if ( !entry ) {
LDEBUGF("Didn't find file %s\n",name);
if ( file->write && (flags & O_CREAT) ) {
rc = fat_create_file(name,
&(file->fatfile),
&(dir->fatdir));
if (rc < 0) {
DEBUGF("Couldn't create %s in %s\n",name,pathnamecopy);
errno = EIO;
file->busy = false;
closedir_uncached(dir);
return rc * 10 - 6;
}
#ifdef HAVE_DIRCACHE
dircache_add_file(pathname, file->fatfile.firstcluster);
#endif
file->size = 0;
file->attr = 0;
}
else {
DEBUGF("Couldn't find %s in %s\n",name,pathnamecopy);
errno = ENOENT;
file->busy = false;
closedir_uncached(dir);
return -7;
}
} else {
if(file->write && (file->attr & FAT_ATTR_DIRECTORY)) {
errno = EISDIR;
file->busy = false;
closedir_uncached(dir);
return -8;
}
}
closedir_uncached(dir);
file->cacheoffset = -1;
file->fileoffset = 0;
if (file->write && (flags & O_APPEND)) {
rc = lseek(fd,0,SEEK_END);
if (rc < 0 )
return rc * 10 - 9;
}
#ifdef HAVE_DIRCACHE
if (file->write)
dircache_bind(fd, pathname);
#endif
return fd;
}
int file_open(const char* pathname, int flags)
{
/* By default, use the dircache if available. */
return open_internal(pathname, flags, true);
}
int close(int fd)
{
struct filedesc* file = &openfiles[fd];
int rc = 0;
LDEBUGF("close(%d)\n", fd);
if (fd < 0 || fd > MAX_OPEN_FILES-1) {
errno = EINVAL;
return -1;
}
if (!file->busy) {
errno = EBADF;
return -2;
}
if (file->write) {
rc = fsync(fd);
if (rc < 0)
return rc * 10 - 3;
#ifdef HAVE_DIRCACHE
dircache_update_filesize(fd, file->size, file->fatfile.firstcluster);
dircache_update_filetime(fd);
#endif
}
file->busy = false;
return 0;
}
int fsync(int fd)
{
struct filedesc* file = &openfiles[fd];
int rc = 0;
LDEBUGF("fsync(%d)\n", fd);
if (fd < 0 || fd > MAX_OPEN_FILES-1) {
errno = EINVAL;
return -1;
}
if (!file->busy) {
errno = EBADF;
return -2;
}
if (file->write) {
/* flush sector cache */
if ( file->dirty ) {
rc = flush_cache(fd);
if (rc < 0)
{
/* when failing, try to close the file anyway */
fat_closewrite(&(file->fatfile), file->size, file->attr);
return rc * 10 - 3;
}
}
/* truncate? */
if (file->trunc) {
rc = ftruncate(fd, file->size);
if (rc < 0)
{
/* when failing, try to close the file anyway */
fat_closewrite(&(file->fatfile), file->size, file->attr);
return rc * 10 - 4;
}
}
/* tie up all loose ends */
rc = fat_closewrite(&(file->fatfile), file->size, file->attr);
if (rc < 0)
return rc * 10 - 5;
}
return 0;
}
int remove(const char* name)
{
int rc;
struct filedesc* file;
/* Can't use dircache now, because we need to access the fat structures. */
int fd = open_internal(name, O_WRONLY, false);
if ( fd < 0 )
return fd * 10 - 1;
file = &openfiles[fd];
#ifdef HAVE_DIRCACHE
dircache_remove(name);
#endif
rc = fat_remove(&(file->fatfile));
if ( rc < 0 ) {
DEBUGF("Failed removing file: %d\n", rc);
errno = EIO;
return rc * 10 - 3;
}
file->size = 0;
rc = close(fd);
if (rc<0)
return rc * 10 - 4;
return 0;
}
int rename(const char* path, const char* newpath)
{
int rc, fd;
DIR_UNCACHED* dir;
char* nameptr;
char* dirptr;
struct filedesc* file;
char newpath2[MAX_PATH];
/* verify new path does not already exist */
/* If it is a directory, errno == EISDIR if the name exists */
fd = open(newpath, O_RDONLY);
if ( fd >= 0 || errno == EISDIR) {
close(fd);
errno = EBUSY;
return -1;
}
close(fd);
fd = open_internal(path, O_RDONLY, false);
if ( fd < 0 ) {
errno = EIO;
return fd * 10 - 2;
}
/* extract new file name */
nameptr = strrchr(newpath,'/');
if (nameptr)
nameptr++;
else {
close(fd);
return - 3;
}
/* Extract new path */
strcpy(newpath2, newpath);
dirptr = strrchr(newpath2,'/');
if(dirptr)
*dirptr = 0;
else {
close(fd);
return - 4;
}
dirptr = newpath2;
if(strlen(dirptr) == 0) {
dirptr = "/";
}
dir = opendir_uncached(dirptr);
if(!dir) {
close(fd);
return - 5;
}
file = &openfiles[fd];
rc = fat_rename(&file->fatfile, &dir->fatdir, nameptr,
file->size, file->attr);
#ifdef HAVE_MULTIVOLUME
if ( rc == -1) {
close(fd);
closedir_uncached(dir);
DEBUGF("Failed renaming file across volumnes: %d\n", rc);
errno = EXDEV;
return -6;
}
#endif
if ( rc < 0 ) {
close(fd);
closedir_uncached(dir);
DEBUGF("Failed renaming file: %d\n", rc);
errno = EIO;
return rc * 10 - 7;
}
#ifdef HAVE_DIRCACHE
dircache_rename(path, newpath);
#endif
rc = close(fd);
if (rc<0) {
closedir_uncached(dir);
errno = EIO;
return rc * 10 - 8;
}
rc = closedir_uncached(dir);
if (rc<0) {
errno = EIO;
return rc * 10 - 9;
}
return 0;
}
int ftruncate(int fd, off_t size)
{
int rc, sector;
struct filedesc* file = &openfiles[fd];
sector = size / SECTOR_SIZE;
if (size % SECTOR_SIZE)
sector++;
rc = fat_seek(&(file->fatfile), sector);
if (rc < 0) {
errno = EIO;
return rc * 10 - 1;
}
rc = fat_truncate(&(file->fatfile));
if (rc < 0) {
errno = EIO;
return rc * 10 - 2;
}
file->size = size;
#ifdef HAVE_DIRCACHE
dircache_update_filesize(fd, size, file->fatfile.firstcluster);
#endif
return 0;
}
static int flush_cache(int fd)
{
int rc;
struct filedesc* file = &openfiles[fd];
long sector = file->fileoffset / SECTOR_SIZE;
DEBUGF("Flushing dirty sector cache\n");
/* make sure we are on correct sector */
rc = fat_seek(&(file->fatfile), sector);
if ( rc < 0 )
return rc * 10 - 3;
rc = fat_readwrite(&(file->fatfile), 1, file->cache, true );
if ( rc < 0 ) {
if(file->fatfile.eof)
errno = ENOSPC;
return rc * 10 - 2;
}
file->dirty = false;
return 0;
}
static int readwrite(int fd, void* buf, long count, bool write)
{
long sectors;
long nread=0;
struct filedesc* file;
int rc;
#ifdef STORAGE_NEEDS_ALIGN
long i;
int rc2;
#endif
if (fd < 0 || fd > MAX_OPEN_FILES-1) {
errno = EINVAL;
return -1;
}
file = &openfiles[fd];
if ( !file->busy ) {
errno = EBADF;
return -1;
}
if(file->attr & FAT_ATTR_DIRECTORY) {
errno = EISDIR;
return -1;
}
LDEBUGF( "readwrite(%d,%lx,%ld,%s)\n",
fd,(long)buf,count,write?"write":"read");
/* attempt to read past EOF? */
if (!write && count > file->size - file->fileoffset)
count = file->size - file->fileoffset;
/* any head bytes? */
if ( file->cacheoffset != -1 ) {
int offs = file->cacheoffset;
int headbytes = MIN(count, SECTOR_SIZE - offs);
if (write) {
memcpy( file->cache + offs, buf, headbytes );
file->dirty = true;
}
else {
memcpy( buf, file->cache + offs, headbytes );
}
if (offs + headbytes == SECTOR_SIZE) {
if (file->dirty) {
rc = flush_cache(fd);
if ( rc < 0 ) {
errno = EIO;
return rc * 10 - 2;
}
}
file->cacheoffset = -1;
}
else {
file->cacheoffset += headbytes;
}
nread = headbytes;
count -= headbytes;
}
/* If the buffer has been modified, either it has been flushed already
* (if (offs+headbytes == SECTOR_SIZE)...) or does not need to be (no
* more data to follow in this call). Do NOT flush here. */
/* read/write whole sectors right into/from the supplied buffer */
sectors = count / SECTOR_SIZE;
rc = 0;
if ( sectors ) {
#ifdef STORAGE_NEEDS_ALIGN
if (((uint32_t)buf + nread) & (CACHEALIGN_SIZE - 1))
for (i = 0; i < sectors; i++)
{
if (write) memcpy(file->cache, buf+nread+i*SECTOR_SIZE, SECTOR_SIZE);
rc2 = fat_readwrite(&(file->fatfile), 1, file->cache, write );
if (rc2 < 0)
{
rc = rc2;
break;
}
else rc += rc2;
if (!write) memcpy(buf+nread+i*SECTOR_SIZE, file->cache, SECTOR_SIZE);
}
else
#endif
rc = fat_readwrite(&(file->fatfile), sectors, (unsigned char*)buf+nread, write );
if ( rc < 0 ) {
DEBUGF("Failed read/writing %ld sectors\n",sectors);
errno = EIO;
if(write && file->fatfile.eof) {
DEBUGF("No space left on device\n");
errno = ENOSPC;
} else {
file->fileoffset += nread;
}
file->cacheoffset = -1;
/* adjust file size to length written */
if ( write && file->fileoffset > file->size )
{
file->size = file->fileoffset;
#ifdef HAVE_DIRCACHE
dircache_update_filesize(fd, file->size, file->fatfile.firstcluster);
#endif
}
return nread ? nread : rc * 10 - 4;
}
else {
if ( rc > 0 ) {
nread += rc * SECTOR_SIZE;
count -= sectors * SECTOR_SIZE;
/* if eof, skip tail bytes */
if ( rc < sectors )
count = 0;
}
else {
/* eof */
count=0;
}
file->cacheoffset = -1;
}
}
/* any tail bytes? */
if ( count ) {
if (write) {
if ( file->fileoffset + nread < file->size ) {
/* sector is only partially filled. copy-back from disk */
LDEBUGF("Copy-back tail cache\n");
rc = fat_readwrite(&(file->fatfile), 1, file->cache, false );
if ( rc < 0 ) {
DEBUGF("Failed writing\n");
errno = EIO;
file->fileoffset += nread;
file->cacheoffset = -1;
/* adjust file size to length written */
if ( file->fileoffset > file->size )
{
file->size = file->fileoffset;
#ifdef HAVE_DIRCACHE
dircache_update_filesize(fd, file->size, file->fatfile.firstcluster);
#endif
}
return nread ? nread : rc * 10 - 5;
}
/* seek back one sector to put file position right */
rc = fat_seek(&(file->fatfile),
(file->fileoffset + nread) /
SECTOR_SIZE);
if ( rc < 0 ) {
DEBUGF("fat_seek() failed\n");
errno = EIO;
file->fileoffset += nread;
file->cacheoffset = -1;
/* adjust file size to length written */
if ( file->fileoffset > file->size )
{
file->size = file->fileoffset;
#ifdef HAVE_DIRCACHE
dircache_update_filesize(fd, file->size, file->fatfile.firstcluster);
#endif
}
return nread ? nread : rc * 10 - 6;
}
}
memcpy( file->cache, (unsigned char*)buf + nread, count );
file->dirty = true;
}
else {
rc = fat_readwrite(&(file->fatfile), 1, file->cache,false);
if (rc < 1 ) {
DEBUGF("Failed caching sector\n");
errno = EIO;
file->fileoffset += nread;
file->cacheoffset = -1;
return nread ? nread : rc * 10 - 7;
}
memcpy( (unsigned char*)buf + nread, file->cache, count );
}
nread += count;
file->cacheoffset = count;
}
file->fileoffset += nread;
LDEBUGF("fileoffset: %ld\n", file->fileoffset);
/* adjust file size to length written */
if ( write && file->fileoffset > file->size )
{
file->size = file->fileoffset;
#ifdef HAVE_DIRCACHE
dircache_update_filesize(fd, file->size, file->fatfile.firstcluster);
#endif
}
return nread;
}
ssize_t write(int fd, const void* buf, size_t count)
{
if (!openfiles[fd].write) {
errno = EACCES;
return -1;
}
return readwrite(fd, (void *)buf, count, true);
}
ssize_t read(int fd, void* buf, size_t count)
{
return readwrite(fd, buf, count, false);
}
off_t lseek(int fd, off_t offset, int whence)
{
off_t pos;
long newsector;
long oldsector;
int sectoroffset;
int rc;
struct filedesc* file = &openfiles[fd];
LDEBUGF("lseek(%d,%ld,%d)\n",fd,offset,whence);
if (fd < 0 || fd > MAX_OPEN_FILES-1) {
errno = EINVAL;
return -1;
}
if ( !file->busy ) {
errno = EBADF;
return -1;
}
switch ( whence ) {
case SEEK_SET:
pos = offset;
break;
case SEEK_CUR:
pos = file->fileoffset + offset;
break;
case SEEK_END:
pos = file->size + offset;
break;
default:
errno = EINVAL;
return -2;
}
if ((pos < 0) || (pos > file->size)) {
errno = EINVAL;
return -3;
}
/* new sector? */
newsector = pos / SECTOR_SIZE;
oldsector = file->fileoffset / SECTOR_SIZE;
sectoroffset = pos % SECTOR_SIZE;
if ( (newsector != oldsector) ||
((file->cacheoffset==-1) && sectoroffset) ) {
if ( newsector != oldsector ) {
if (file->dirty) {
rc = flush_cache(fd);
if (rc < 0)
return rc * 10 - 5;
}
rc = fat_seek(&(file->fatfile), newsector);
if ( rc < 0 ) {
errno = EIO;
return rc * 10 - 4;
}
}
if ( sectoroffset ) {
rc = fat_readwrite(&(file->fatfile), 1, file->cache ,false);
if ( rc < 0 ) {
errno = EIO;
return rc * 10 - 6;
}
file->cacheoffset = sectoroffset;
}
else
file->cacheoffset = -1;
}
else
if ( file->cacheoffset != -1 )
file->cacheoffset = sectoroffset;
file->fileoffset = pos;
return pos;
}
off_t filesize(int fd)
{
struct filedesc* file = &openfiles[fd];
if (fd < 0 || fd > MAX_OPEN_FILES-1) {
errno = EINVAL;
return -1;
}
if ( !file->busy ) {
errno = EBADF;
return -1;
}
return file->size;
}
/* release all file handles on a given volume "by force", to avoid leaks */
int release_files(int volume)
{
struct filedesc* pfile = openfiles;
int fd;
int closed = 0;
for ( fd=0; fd<MAX_OPEN_FILES; fd++, pfile++)
{
#ifdef HAVE_MULTIVOLUME
if (pfile->fatfile.volume == volume)
#else
(void)volume;
#endif
{
pfile->busy = false; /* mark as available, no further action */
closed++;
}
}
return closed; /* return how many we did */
}
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