rockbox/firmware/include/file_internal.h
Michael Sevakis a931c76b3a Do some debug and preparatory work for ramcache and playlist
The file system rework introduced incompatibility between dircache
and the tagcache ramcache and playlist dircache path caching. This
update makes changes to filesystem code to reintegrate all that.

It also fixes a couple bugs that were found when vetting all the
code. The filestream cache was being reset without regard to
the stream even if it was shared in write mode (made work of
.playlist_control). Better handling of unmounting gives files a
better go at force-closing them without risk to disk integrity.

Did some miscellaneous pedantic changes. Improved efficiency of
testing a file's existence (a little) since the path parser will
be shared between file code and parsing for the sake of finding
dircache references, not duplicated as before.

This commit doesn't reenable said items just for the sake of
keeping changes separate and related.

Plan for the next is to enable dircache again for the playlists
(easy peasy) and reenable tagcache ramcache but *without* the
dircache path caching because it's rather substantial to change
in itself. The ramcache will still function without dircache.

Change-Id: I7e2a9910b866251fa8333e1275f72fcfc8425d2d
2017-01-17 14:35:36 -05:00

386 lines
14 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2014 by Michael Sevakis
*
* 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.
*
****************************************************************************/
#ifndef _FILE_INTERNAL_H_
#define _FILE_INTERNAL_H_
#include <sys/types.h>
#include <stdlib.h>
#include "mv.h"
#include "linked_list.h"
#include "mutex.h"
#include "mrsw_lock.h"
#include "fs_attr.h"
#include "fat.h"
#ifdef HAVE_DIRCACHE
#include "dircache.h"
#endif
/** Tuneable parameters **/
/* limits for number of open descriptors - if you increase these values, make
certain that the disk cache has enough available buffers */
#define MAX_OPEN_FILES 11
#define MAX_OPEN_DIRS 12
#define MAX_OPEN_HANDLES (MAX_OPEN_FILES+MAX_OPEN_DIRS)
/* internal functions open streams as well; make sure they don't fail if all
user descs are busy; this needs to be at least the greatest quantity needed
at once by all internal functions */
#ifdef HAVE_DIRCACHE
#define AUX_FILEOBJS 3
#else
#define AUX_FILEOBJS 2
#endif
/* number of components statically allocated to handle the vast majority
of path depths; should maybe be tuned for >= 90th percentile but for now,
imma just guessing based on something like:
root + 'Music' + 'Artist' + 'Album' + 'Disc N' + filename */
#define STATIC_PATHCOMP_NUM 6
#define MAX_NAME 255
/* unsigned value that will also hold the off_t range we need without
overflow */
#define file_size_t uint32_t
#ifdef __USE_FILE_OFFSET64
/* if we want, we can deal with files up to 2^32-1 bytes-- the full FAT16/32
range */
#define FILE_SIZE_MAX (0xffffffffu)
#else
/* file contents and size will be preserved by the APIs so long as ftruncate()
isn't used; bytes passed 2^31-1 will not accessible nor will writes succeed
that would extend the file beyond the max for a 32-bit off_t */
#define FILE_SIZE_MAX (0x7fffffffu)
#endif
/* if file is "large(ish)", then get rid of the contents now rather than
lazily when the file is synced or closed in order to free-up space */
#define O_TRUNC_THRESH 65536
/* default attributes when creating new files and directories */
#define ATTR_NEW_FILE (ATTR_ARCHIVE)
#define ATTR_NEW_DIRECTORY (ATTR_DIRECTORY)
#define ATTR_SYSTEM_ROOT (ATTR_SYSROOT | ATTR_DIRECTORY)
#define ATTR_MOUNT_POINT (ATTR_VOLUME | ATTR_DIRECTORY)
/** File sector cache **/
enum filestr_cache_flags
{
FSC_DIRTY = 0x1, /* buffer is dirty (needs writeback) */
FSC_NEW = 0x2, /* buffer is new (never yet written) */
};
struct filestr_cache
{
uint8_t *buffer; /* buffer to hold sector */
unsigned long sector; /* file sector that is in buffer */
unsigned int flags; /* FSC_* bits */
};
void file_cache_init(struct filestr_cache *cachep);
void file_cache_reset(struct filestr_cache *cachep);
void file_cache_alloc(struct filestr_cache *cachep);
void file_cache_free(struct filestr_cache *cachep);
/** Common bitflags used throughout **/
/* bitflags used by open files and descriptors */
enum fildes_and_obj_flags
{
/* used in descriptor and common */
FDO_BUSY = 0x0001, /* descriptor/object is in use */
/* only used in individual stream descriptor */
FD_WRITE = 0x0002, /* descriptor has write mode */
FD_WRONLY = 0x0004, /* descriptor is write mode only */
FD_APPEND = 0x0008, /* descriptor is append mode */
FD_NONEXIST = 0x8000, /* closed but not freed (uncombined) */
/* only used as common flags */
FO_DIRECTORY = 0x0010, /* fileobj is a directory */
FO_TRUNC = 0x0020, /* fileobj is opened to be truncated */
FO_REMOVED = 0x0040, /* fileobj was deleted while open */
FO_SINGLE = 0x0080, /* fileobj has only one stream open */
FDO_MASK = 0x00ff,
FDO_CHG_MASK = FO_TRUNC, /* fileobj permitted external change */
/* bitflags that instruct various 'open' functions how to behave;
* saved in stream flags (only) but not used by manager */
FF_FILE = 0x00000000, /* expect file; accept file only */
FF_DIR = 0x00010000, /* expect dir; accept dir only */
FF_ANYTYPE = 0x00020000, /* succeed if either file or dir */
FF_TYPEMASK = 0x00030000, /* mask of typeflags */
FF_CREAT = 0x00040000, /* create if file doesn't exist */
FF_EXCL = 0x00080000, /* fail if creating and file exists */
FF_CHECKPREFIX = 0x00100000, /* detect if file is prefix of path */
FF_NOISO = 0x00200000, /* do not decode ISO filenames to UTF-8 */
FF_PROBE = 0x00400000, /* only test existence; don't open */
FF_CACHEONLY = 0x00800000, /* succeed only if in dircache */
FF_SELFINFO = 0x01000000, /* return info on self as well */
FF_MASK = 0x01ff0000,
};
/** Common data structures used throughout **/
/* basic file information about its location */
struct file_base_info
{
union {
#ifdef HAVE_MULTIVOLUME
int volume; /* file's volume (overlaps fatfile.volume) */
#endif
#if CONFIG_PLATFORM & PLATFORM_NATIVE
struct fat_file fatfile; /* FS driver file info */
#endif
};
#ifdef HAVE_DIRCACHE
struct dircache_file dcfile; /* dircache file info */
#endif
};
#define BASEINFO_VOL(infop) \
IF_MV_VOL((infop)->volume)
/* open files binding item */
struct file_base_binding
{
struct ll_node node; /* list item node (first!) */
struct file_base_info info; /* basic file info */
};
#define BASEBINDING_VOL(bindp) \
BASEINFO_VOL(&(bindp)->info)
/* directory scanning position info */
struct dirscan_info
{
#if CONFIG_PLATFORM & PLATFORM_NATIVE
struct fat_dirscan_info fatscan; /* FS driver scan info */
#endif
#ifdef HAVE_DIRCACHE
struct dircache_file dcscan; /* dircache scan info */
#endif
};
/* describes the file as an open stream */
struct filestr_base
{
struct ll_node node; /* list item node (first!) */
uint32_t flags; /* F[DF]_* bits of this stream */
struct filestr_cache cache; /* stream-local cache */
struct filestr_cache *cachep; /* the cache in use (local or shared) */
struct file_base_info *infop; /* base file information */
struct fat_filestr fatstr; /* FS driver information */
struct file_base_binding *bindp; /* common binding for file/dir */
struct mutex *mtx; /* serialization for this stream */
};
void filestr_base_init(struct filestr_base *stream);
void filestr_base_destroy(struct filestr_base *stream);
void filestr_alloc_cache(struct filestr_base *stream);
void filestr_free_cache(struct filestr_base *stream);
void filestr_assign_cache(struct filestr_base *stream,
struct filestr_cache *cachep);
void filestr_copy_cache(struct filestr_base *stream,
struct filestr_cache *cachep);
void filestr_discard_cache(struct filestr_base *stream);
/* allocates a cache buffer if needed and returns the cache pointer */
static inline struct filestr_cache *
filestr_get_cache(struct filestr_base *stream)
{
struct filestr_cache *cachep = stream->cachep;
if (!cachep->buffer)
filestr_alloc_cache(stream);
return cachep;
}
static inline void filestr_lock(struct filestr_base *stream)
{
mutex_lock(stream->mtx);
}
static inline void filestr_unlock(struct filestr_base *stream)
{
mutex_unlock(stream->mtx);
}
/* stream lock doesn't have to be used if getting RW lock writer access */
#define FILESTR_WRITER 0
#define FILESTR_READER 1
#define FILESTR_LOCK(type, stream) \
({ if (FILESTR_##type) filestr_lock(stream); })
#define FILESTR_UNLOCK(type, stream) \
({ if (FILESTR_##type) filestr_unlock(stream); })
/* auxilliary attributes - out of the way of regular ATTR_* bits */
#define ATTR_SYSROOT (0x8000)
#define ATTR_PREFIX (0x4000)
/* structure to return detailed information about what you opened */
struct path_component_info
{
const char *name; /* pointer to name within 'path' (OUT) */
size_t length; /* length of component within 'path' */
file_size_t filesize; /* size of the opened file (0 if dir) */
unsigned int attr; /* attributes of this component */
struct file_base_info *prefixp; /* base info to check as prefix
(IN if FF_CHECKPREFIX) */
union {
struct file_base_info parentinfo; /* parent directory base info of file
(if not FF_SELFINFO) */
struct file_base_info info; /* base info of file itself
(if FF_SELFINFO) */
};
};
int open_stream_internal(const char *path, unsigned int callflags,
struct filestr_base *stream,
struct path_component_info *compinfo);
int close_stream_internal(struct filestr_base *stream);
int create_stream_internal(struct file_base_info *parentinfop,
const char *basename, size_t length,
unsigned int attr, unsigned int callflags,
struct filestr_base *stream);
int remove_stream_internal(const char *path, struct filestr_base *stream,
unsigned int callflags);
int test_stream_exists_internal(const char *path, unsigned int callflags);
int open_noiso_internal(const char *path, int oflag); /* file.c */
void force_close_writer_internal(struct filestr_base *stream); /* file.c */
struct dirent;
int uncached_readdir_dirent(struct filestr_base *stream,
struct dirscan_info *scanp,
struct dirent *entry);
void uncached_rewinddir_dirent(struct dirscan_info *scanp);
int uncached_readdir_internal(struct filestr_base *stream,
struct file_base_info *infop,
struct fat_direntry *fatent);
void uncached_rewinddir_internal(struct file_base_info *infop);
int test_dir_empty_internal(struct filestr_base *stream);
struct dirinfo_internal
{
unsigned int attr;
file_size_t size;
uint16_t wrtdate;
uint16_t wrttime;
};
/** Synchronization used throughout **/
/* acquire the filesystem lock as READER */
static inline void file_internal_lock_READER(void)
{
extern struct mrsw_lock file_internal_mrsw;
mrsw_read_acquire(&file_internal_mrsw);
}
/* release the filesystem lock as READER */
static inline void file_internal_unlock_READER(void)
{
extern struct mrsw_lock file_internal_mrsw;
mrsw_read_release(&file_internal_mrsw);
}
/* acquire the filesystem lock as WRITER */
static inline void file_internal_lock_WRITER(void)
{
extern struct mrsw_lock file_internal_mrsw;
mrsw_write_acquire(&file_internal_mrsw);
}
/* release the filesystem lock as WRITER */
static inline void file_internal_unlock_WRITER(void)
{
extern struct mrsw_lock file_internal_mrsw;
mrsw_write_release(&file_internal_mrsw);
}
#define ERRNO 0 /* maintain errno value */
#define RC 0 /* maintain rc value */
/* NOTES: if _errno is a non-constant expression, it must set an error
* number and not return the ERRNO constant which will merely set
* errno to zero, not preserve the current value; if you must set
* errno to zero, set it explicitly, not in the macro
*
* if _rc is constant-expression evaluation to 'RC', then rc will
* NOT be altered; i.e. if you must set rc to zero, set it explicitly,
* not in the macro
*/
#define FILE_SET_CODE(_name, _keepcode, _value) \
({ __builtin_constant_p(_value) ? \
({ if ((_value) != (_keepcode)) _name = (_value); }) : \
({ _name = (_value); }); })
/* set errno and rc and proceed to the "file_error:" label */
#define FILE_ERROR(_errno, _rc) \
({ FILE_SET_CODE(errno, ERRNO, (_errno)); \
FILE_SET_CODE(rc, RC, (_rc)); \
goto file_error; })
/* set errno and return a value at the point of invocation */
#define FILE_ERROR_RETURN(_errno, _rc...) \
({ FILE_SET_CODE(errno, ERRNO, _errno); \
return _rc; })
/* set errno and return code, no branching */
#define FILE_ERROR_SET(_errno, _rc) \
({ FILE_SET_CODE(errno, ERRNO, (_errno)); \
FILE_SET_CODE(rc, RC, (_rc)); })
/** Misc. stuff **/
/* iterate through all the volumes if volume < 0, else just the given volume */
#define FOR_EACH_VOLUME(volume, i) \
for (int i = (IF_MV_VOL(volume) >= 0 ? IF_MV_VOL(volume) : 0), \
_end = (IF_MV_VOL(volume) >= 0 ? i : NUM_VOLUMES-1); \
i <= _end; i++)
/* return a pointer to the static struct fat_direntry */
static inline struct fat_direntry *get_dir_fatent(void)
{
extern struct fat_direntry dir_fatent;
return &dir_fatent;
}
void iso_decode_d_name(char *d_name);
#ifdef HAVE_DIRCACHE
void empty_dirent(struct dirent *entry);
void fill_dirinfo_native(struct dirinfo_native *din);
#endif /* HAVE_DIRCACHE */
void filesystem_init(void) INIT_ATTR;
#endif /* _FILE_INTERNAL_H_ */