only get the file pointer if fd is actually valid.
[kugel-rb.git] / firmware / common / file.c
blob75adc8756fc8d205a00622cd1c86d7be6837b1a5
1 /***************************************************************************
2 * __________ __ ___.
3 * Open \______ \ ____ ____ | | _\_ |__ _______ ___
4 * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
5 * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
6 * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
7 * \/ \/ \/ \/ \/
8 * $Id$
10 * Copyright (C) 2002 by Björn Stenberg
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version 2
15 * of the License, or (at your option) any later version.
17 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
18 * KIND, either express or implied.
20 ****************************************************************************/
21 #include <string.h>
22 #include <errno.h>
23 #include <stdbool.h>
24 #include "file.h"
25 #include "fat.h"
26 #include "dir_uncached.h"
27 #include "debug.h"
28 #include "dircache.h"
29 #include "filefuncs.h"
30 #include "system.h"
33 These functions provide a roughly POSIX-compatible file IO API.
35 Since the fat32 driver only manages sectors, we maintain a one-sector
36 cache for each open file. This way we can provide byte access without
37 having to re-read the sector each time.
38 The penalty is the RAM used for the cache and slightly more complex code.
41 struct filedesc {
42 unsigned char cache[SECTOR_SIZE];
43 int cacheoffset; /* invariant: 0 <= cacheoffset <= SECTOR_SIZE */
44 long fileoffset;
45 long size;
46 int attr;
47 struct fat_file fatfile;
48 bool busy;
49 bool write;
50 bool dirty;
51 bool trunc;
54 static struct filedesc openfiles[MAX_OPEN_FILES];
56 static int flush_cache(int fd);
58 int creat(const char *pathname)
60 return open(pathname, O_WRONLY|O_CREAT|O_TRUNC);
63 static int open_internal(const char* pathname, int flags, bool use_cache)
65 DIR_UNCACHED* dir;
66 struct dirent_uncached* entry;
67 int fd;
68 char pathnamecopy[MAX_PATH];
69 char* name;
70 struct filedesc* file = NULL;
71 int rc;
72 #ifndef HAVE_DIRCACHE
73 (void)use_cache;
74 #endif
76 LDEBUGF("open(\"%s\",%d)\n",pathname,flags);
78 if ( pathname[0] != '/' ) {
79 DEBUGF("'%s' is not an absolute path.\n",pathname);
80 DEBUGF("Only absolute pathnames supported at the moment\n");
81 errno = EINVAL;
82 return -1;
85 /* find a free file descriptor */
86 for ( fd=0; fd<MAX_OPEN_FILES; fd++ )
87 if ( !openfiles[fd].busy )
88 break;
90 if ( fd == MAX_OPEN_FILES ) {
91 DEBUGF("Too many files open\n");
92 errno = EMFILE;
93 return -2;
96 file = &openfiles[fd];
97 memset(file, 0, sizeof(struct filedesc));
99 if (flags & (O_RDWR | O_WRONLY)) {
100 file->write = true;
102 if (flags & O_TRUNC)
103 file->trunc = true;
105 file->busy = true;
107 #ifdef HAVE_DIRCACHE
108 if (dircache_is_enabled() && !file->write && use_cache)
110 const struct dircache_entry *ce;
111 # ifdef HAVE_MULTIVOLUME
112 int volume = strip_volume(pathname, pathnamecopy);
113 # endif
115 ce = dircache_get_entry_ptr(pathname);
116 if (!ce)
118 errno = ENOENT;
119 file->busy = false;
120 return -7;
123 fat_open(IF_MV2(volume,)
124 ce->startcluster,
125 &(file->fatfile),
126 NULL);
127 file->size = ce->size;
128 file->attr = ce->attribute;
129 file->cacheoffset = -1;
130 file->fileoffset = 0;
132 return fd;
134 #endif
136 strlcpy(pathnamecopy, pathname, sizeof(pathnamecopy));
138 /* locate filename */
139 name=strrchr(pathnamecopy+1,'/');
140 if ( name ) {
141 *name = 0;
142 dir = opendir_uncached(pathnamecopy);
143 *name = '/';
144 name++;
146 else {
147 dir = opendir_uncached("/");
148 name = pathnamecopy+1;
150 if (!dir) {
151 DEBUGF("Failed opening dir\n");
152 errno = EIO;
153 file->busy = false;
154 return -4;
157 if(name[0] == 0) {
158 DEBUGF("Empty file name\n");
159 errno = EINVAL;
160 file->busy = false;
161 closedir_uncached(dir);
162 return -5;
165 /* scan dir for name */
166 while ((entry = readdir_uncached(dir))) {
167 if ( !strcasecmp(name, entry->d_name) ) {
168 fat_open(IF_MV2(dir->fatdir.file.volume,)
169 entry->startcluster,
170 &(file->fatfile),
171 &(dir->fatdir));
172 file->size = file->trunc ? 0 : entry->size;
173 file->attr = entry->attribute;
174 break;
178 if ( !entry ) {
179 LDEBUGF("Didn't find file %s\n",name);
180 if ( file->write && (flags & O_CREAT) ) {
181 rc = fat_create_file(name,
182 &(file->fatfile),
183 &(dir->fatdir));
184 if (rc < 0) {
185 DEBUGF("Couldn't create %s in %s\n",name,pathnamecopy);
186 errno = EIO;
187 file->busy = false;
188 closedir_uncached(dir);
189 return rc * 10 - 6;
191 #ifdef HAVE_DIRCACHE
192 dircache_add_file(pathname, file->fatfile.firstcluster);
193 #endif
194 file->size = 0;
195 file->attr = 0;
197 else {
198 DEBUGF("Couldn't find %s in %s\n",name,pathnamecopy);
199 errno = ENOENT;
200 file->busy = false;
201 closedir_uncached(dir);
202 return -7;
204 } else {
205 if(file->write && (file->attr & FAT_ATTR_DIRECTORY)) {
206 errno = EISDIR;
207 file->busy = false;
208 closedir_uncached(dir);
209 return -8;
212 closedir_uncached(dir);
214 file->cacheoffset = -1;
215 file->fileoffset = 0;
217 if (file->write && (flags & O_APPEND)) {
218 rc = lseek(fd,0,SEEK_END);
219 if (rc < 0 )
220 return rc * 10 - 9;
223 #ifdef HAVE_DIRCACHE
224 if (file->write)
225 dircache_bind(fd, pathname);
226 #endif
228 return fd;
231 int open(const char* pathname, int flags)
233 /* By default, use the dircache if available. */
234 return open_internal(pathname, flags, true);
237 int close(int fd)
239 struct filedesc* file = &openfiles[fd];
240 int rc = 0;
242 LDEBUGF("close(%d)\n", fd);
244 if (fd < 0 || fd > MAX_OPEN_FILES-1) {
245 errno = EINVAL;
246 return -1;
248 if (!file->busy) {
249 errno = EBADF;
250 return -2;
252 if (file->write) {
253 rc = fsync(fd);
254 if (rc < 0)
255 return rc * 10 - 3;
256 #ifdef HAVE_DIRCACHE
257 dircache_update_filesize(fd, file->size, file->fatfile.firstcluster);
258 dircache_update_filetime(fd);
259 #endif
262 file->busy = false;
263 return 0;
266 int fsync(int fd)
268 struct filedesc* file = &openfiles[fd];
269 int rc = 0;
271 LDEBUGF("fsync(%d)\n", fd);
273 if (fd < 0 || fd > MAX_OPEN_FILES-1) {
274 errno = EINVAL;
275 return -1;
277 if (!file->busy) {
278 errno = EBADF;
279 return -2;
281 if (file->write) {
282 /* flush sector cache */
283 if ( file->dirty ) {
284 rc = flush_cache(fd);
285 if (rc < 0)
287 /* when failing, try to close the file anyway */
288 fat_closewrite(&(file->fatfile), file->size, file->attr);
289 return rc * 10 - 3;
293 /* truncate? */
294 if (file->trunc) {
295 rc = ftruncate(fd, file->size);
296 if (rc < 0)
298 /* when failing, try to close the file anyway */
299 fat_closewrite(&(file->fatfile), file->size, file->attr);
300 return rc * 10 - 4;
304 /* tie up all loose ends */
305 rc = fat_closewrite(&(file->fatfile), file->size, file->attr);
306 if (rc < 0)
307 return rc * 10 - 5;
309 return 0;
312 int remove(const char* name)
314 int rc;
315 struct filedesc* file;
316 /* Can't use dircache now, because we need to access the fat structures. */
317 int fd = open_internal(name, O_WRONLY, false);
318 if ( fd < 0 )
319 return fd * 10 - 1;
321 file = &openfiles[fd];
322 #ifdef HAVE_DIRCACHE
323 dircache_remove(name);
324 #endif
325 rc = fat_remove(&(file->fatfile));
326 if ( rc < 0 ) {
327 DEBUGF("Failed removing file: %d\n", rc);
328 errno = EIO;
329 return rc * 10 - 3;
332 file->size = 0;
334 rc = close(fd);
335 if (rc<0)
336 return rc * 10 - 4;
338 return 0;
341 int rename(const char* path, const char* newpath)
343 int rc, fd;
344 DIR_UNCACHED* dir;
345 char* nameptr;
346 char* dirptr;
347 struct filedesc* file;
348 char newpath2[MAX_PATH];
350 /* verify new path does not already exist */
351 /* If it is a directory, errno == EISDIR if the name exists */
352 fd = open(newpath, O_RDONLY);
353 if ( fd >= 0 || errno == EISDIR) {
354 close(fd);
355 errno = EBUSY;
356 return -1;
358 close(fd);
360 fd = open_internal(path, O_RDONLY, false);
361 if ( fd < 0 ) {
362 errno = EIO;
363 return fd * 10 - 2;
366 /* extract new file name */
367 nameptr = strrchr(newpath,'/');
368 if (nameptr)
369 nameptr++;
370 else
371 return - 3;
373 /* Extract new path */
374 strcpy(newpath2, newpath);
376 dirptr = strrchr(newpath2,'/');
377 if(dirptr)
378 *dirptr = 0;
379 else
380 return - 4;
382 dirptr = newpath2;
384 if(strlen(dirptr) == 0) {
385 dirptr = "/";
388 dir = opendir_uncached(dirptr);
389 if(!dir)
390 return - 5;
392 file = &openfiles[fd];
394 rc = fat_rename(&file->fatfile, &dir->fatdir, nameptr,
395 file->size, file->attr);
396 #ifdef HAVE_MULTIVOLUME
397 if ( rc == -1) {
398 DEBUGF("Failed renaming file across volumnes: %d\n", rc);
399 errno = EXDEV;
400 return -6;
402 #endif
403 if ( rc < 0 ) {
404 DEBUGF("Failed renaming file: %d\n", rc);
405 errno = EIO;
406 return rc * 10 - 7;
409 #ifdef HAVE_DIRCACHE
410 dircache_rename(path, newpath);
411 #endif
413 rc = close(fd);
414 if (rc<0) {
415 errno = EIO;
416 return rc * 10 - 8;
419 rc = closedir_uncached(dir);
420 if (rc<0) {
421 errno = EIO;
422 return rc * 10 - 9;
425 return 0;
428 int ftruncate(int fd, off_t size)
430 int rc, sector;
431 struct filedesc* file = &openfiles[fd];
433 sector = size / SECTOR_SIZE;
434 if (size % SECTOR_SIZE)
435 sector++;
437 rc = fat_seek(&(file->fatfile), sector);
438 if (rc < 0) {
439 errno = EIO;
440 return rc * 10 - 1;
443 rc = fat_truncate(&(file->fatfile));
444 if (rc < 0) {
445 errno = EIO;
446 return rc * 10 - 2;
449 file->size = size;
450 #ifdef HAVE_DIRCACHE
451 dircache_update_filesize(fd, size, file->fatfile.firstcluster);
452 #endif
454 return 0;
457 static int flush_cache(int fd)
459 int rc;
460 struct filedesc* file = &openfiles[fd];
461 long sector = file->fileoffset / SECTOR_SIZE;
463 DEBUGF("Flushing dirty sector cache\n");
465 /* make sure we are on correct sector */
466 rc = fat_seek(&(file->fatfile), sector);
467 if ( rc < 0 )
468 return rc * 10 - 3;
470 rc = fat_readwrite(&(file->fatfile), 1, file->cache, true );
472 if ( rc < 0 ) {
473 if(file->fatfile.eof)
474 errno = ENOSPC;
476 return rc * 10 - 2;
479 file->dirty = false;
481 return 0;
484 static int readwrite(int fd, void* buf, long count, bool write)
486 long sectors;
487 long nread=0;
488 struct filedesc* file;
489 int rc;
491 if (fd < 0 || fd > MAX_OPEN_FILES-1) {
492 errno = EINVAL;
493 return -1;
496 file = &openfiles[fd];
498 if ( !file->busy ) {
499 errno = EBADF;
500 return -1;
503 LDEBUGF( "readwrite(%d,%lx,%ld,%s)\n",
504 fd,(long)buf,count,write?"write":"read");
506 /* attempt to read past EOF? */
507 if (!write && count > file->size - file->fileoffset)
508 count = file->size - file->fileoffset;
510 /* any head bytes? */
511 if ( file->cacheoffset != -1 ) {
512 int offs = file->cacheoffset;
513 int headbytes = MIN(count, SECTOR_SIZE - offs);
515 if (write) {
516 memcpy( file->cache + offs, buf, headbytes );
517 file->dirty = true;
519 else {
520 memcpy( buf, file->cache + offs, headbytes );
523 if (offs + headbytes == SECTOR_SIZE) {
524 if (file->dirty) {
525 rc = flush_cache(fd);
526 if ( rc < 0 ) {
527 errno = EIO;
528 return rc * 10 - 2;
531 file->cacheoffset = -1;
533 else {
534 file->cacheoffset += headbytes;
537 nread = headbytes;
538 count -= headbytes;
541 /* If the buffer has been modified, either it has been flushed already
542 * (if (offs+headbytes == SECTOR_SIZE)...) or does not need to be (no
543 * more data to follow in this call). Do NOT flush here. */
545 /* read/write whole sectors right into/from the supplied buffer */
546 sectors = count / SECTOR_SIZE;
547 if ( sectors ) {
548 rc = fat_readwrite(&(file->fatfile), sectors,
549 (unsigned char*)buf+nread, write );
550 if ( rc < 0 ) {
551 DEBUGF("Failed read/writing %ld sectors\n",sectors);
552 errno = EIO;
553 if(write && file->fatfile.eof) {
554 DEBUGF("No space left on device\n");
555 errno = ENOSPC;
556 } else {
557 file->fileoffset += nread;
559 file->cacheoffset = -1;
560 /* adjust file size to length written */
561 if ( write && file->fileoffset > file->size )
563 file->size = file->fileoffset;
564 #ifdef HAVE_DIRCACHE
565 dircache_update_filesize(fd, file->size, file->fatfile.firstcluster);
566 #endif
568 return nread ? nread : rc * 10 - 4;
570 else {
571 if ( rc > 0 ) {
572 nread += rc * SECTOR_SIZE;
573 count -= sectors * SECTOR_SIZE;
575 /* if eof, skip tail bytes */
576 if ( rc < sectors )
577 count = 0;
579 else {
580 /* eof */
581 count=0;
584 file->cacheoffset = -1;
588 /* any tail bytes? */
589 if ( count ) {
590 if (write) {
591 if ( file->fileoffset + nread < file->size ) {
592 /* sector is only partially filled. copy-back from disk */
593 LDEBUGF("Copy-back tail cache\n");
594 rc = fat_readwrite(&(file->fatfile), 1, file->cache, false );
595 if ( rc < 0 ) {
596 DEBUGF("Failed writing\n");
597 errno = EIO;
598 file->fileoffset += nread;
599 file->cacheoffset = -1;
600 /* adjust file size to length written */
601 if ( file->fileoffset > file->size )
603 file->size = file->fileoffset;
604 #ifdef HAVE_DIRCACHE
605 dircache_update_filesize(fd, file->size, file->fatfile.firstcluster);
606 #endif
608 return nread ? nread : rc * 10 - 5;
610 /* seek back one sector to put file position right */
611 rc = fat_seek(&(file->fatfile),
612 (file->fileoffset + nread) /
613 SECTOR_SIZE);
614 if ( rc < 0 ) {
615 DEBUGF("fat_seek() failed\n");
616 errno = EIO;
617 file->fileoffset += nread;
618 file->cacheoffset = -1;
619 /* adjust file size to length written */
620 if ( file->fileoffset > file->size )
622 file->size = file->fileoffset;
623 #ifdef HAVE_DIRCACHE
624 dircache_update_filesize(fd, file->size, file->fatfile.firstcluster);
625 #endif
627 return nread ? nread : rc * 10 - 6;
630 memcpy( file->cache, (unsigned char*)buf + nread, count );
631 file->dirty = true;
633 else {
634 rc = fat_readwrite(&(file->fatfile), 1, &(file->cache),false);
635 if (rc < 1 ) {
636 DEBUGF("Failed caching sector\n");
637 errno = EIO;
638 file->fileoffset += nread;
639 file->cacheoffset = -1;
640 return nread ? nread : rc * 10 - 7;
642 memcpy( (unsigned char*)buf + nread, file->cache, count );
645 nread += count;
646 file->cacheoffset = count;
649 file->fileoffset += nread;
650 LDEBUGF("fileoffset: %ld\n", file->fileoffset);
652 /* adjust file size to length written */
653 if ( write && file->fileoffset > file->size )
655 file->size = file->fileoffset;
656 #ifdef HAVE_DIRCACHE
657 dircache_update_filesize(fd, file->size, file->fatfile.firstcluster);
658 #endif
661 return nread;
664 ssize_t write(int fd, const void* buf, size_t count)
666 if (!openfiles[fd].write) {
667 errno = EACCES;
668 return -1;
670 return readwrite(fd, (void *)buf, count, true);
673 ssize_t read(int fd, void* buf, size_t count)
675 return readwrite(fd, buf, count, false);
679 off_t lseek(int fd, off_t offset, int whence)
681 off_t pos;
682 long newsector;
683 long oldsector;
684 int sectoroffset;
685 int rc;
686 struct filedesc* file = &openfiles[fd];
688 LDEBUGF("lseek(%d,%ld,%d)\n",fd,offset,whence);
690 if (fd < 0 || fd > MAX_OPEN_FILES-1) {
691 errno = EINVAL;
692 return -1;
694 if ( !file->busy ) {
695 errno = EBADF;
696 return -1;
699 switch ( whence ) {
700 case SEEK_SET:
701 pos = offset;
702 break;
704 case SEEK_CUR:
705 pos = file->fileoffset + offset;
706 break;
708 case SEEK_END:
709 pos = file->size + offset;
710 break;
712 default:
713 errno = EINVAL;
714 return -2;
716 if ((pos < 0) || (pos > file->size)) {
717 errno = EINVAL;
718 return -3;
721 /* new sector? */
722 newsector = pos / SECTOR_SIZE;
723 oldsector = file->fileoffset / SECTOR_SIZE;
724 sectoroffset = pos % SECTOR_SIZE;
726 if ( (newsector != oldsector) ||
727 ((file->cacheoffset==-1) && sectoroffset) ) {
729 if ( newsector != oldsector ) {
730 if (file->dirty) {
731 rc = flush_cache(fd);
732 if (rc < 0)
733 return rc * 10 - 5;
736 rc = fat_seek(&(file->fatfile), newsector);
737 if ( rc < 0 ) {
738 errno = EIO;
739 return rc * 10 - 4;
742 if ( sectoroffset ) {
743 rc = fat_readwrite(&(file->fatfile), 1,
744 &(file->cache),false);
745 if ( rc < 0 ) {
746 errno = EIO;
747 return rc * 10 - 6;
749 file->cacheoffset = sectoroffset;
751 else
752 file->cacheoffset = -1;
754 else
755 if ( file->cacheoffset != -1 )
756 file->cacheoffset = sectoroffset;
758 file->fileoffset = pos;
760 return pos;
763 off_t filesize(int fd)
765 struct filedesc* file = &openfiles[fd];
767 if (fd < 0 || fd > MAX_OPEN_FILES-1) {
768 errno = EINVAL;
769 return -1;
771 if ( !file->busy ) {
772 errno = EBADF;
773 return -1;
776 return file->size;
780 #ifdef HAVE_HOTSWAP
781 /* release all file handles on a given volume "by force", to avoid leaks */
782 int release_files(int volume)
784 struct filedesc* pfile = openfiles;
785 int fd;
786 int closed = 0;
787 for ( fd=0; fd<MAX_OPEN_FILES; fd++, pfile++)
789 #ifdef HAVE_MULTIVOLUME
790 if (pfile->fatfile.volume == volume)
791 #else
792 (void)volume;
793 #endif
795 pfile->busy = false; /* mark as available, no further action */
796 closed++;
799 return closed; /* return how many we did */
801 #endif /* #ifdef HAVE_HOTSWAP */