FreeLists / openbeosstorage / [openbeosstorage] Re: Kernel Interface Design

[Keith Poole <keef@xxxxxxxxxxxxxxx>]

The kernel returns errors defined in include/sys/errors.h:

#define ERR_GENERAL              -1
#define ERR_NO_MEMORY            ERR_GENERAL-1
#define ERR_IO_ERROR             ERR_GENERAL-2
#define ERR_INVALID_ARGS         ERR_GENERAL-3
#define ERR_TIMED_OUT            ERR_GENERAL-4
#define ERR_NOT_ALLOWED          ERR_GENERAL-5
#define ERR_PERMISSION_DENIED    ERR_GENERAL-6
#define ERR_INVALID_BINARY       ERR_GENERAL-7
#define ERR_INVALID_HANDLE       ERR_GENERAL-8
#define ERR_NO_MORE_HANDLES      ERR_GENERAL-9
#define ERR_UNIMPLEMENTED        ERR_GENERAL-10
#define ERR_TOO_BIG              ERR_GENERAL-11
#define ERR_NOT_FOUND            ERR_GENERAL-12
#define ERR_NOT_IMPLEMENTED_YET  ERR_GENERAL-13
#define ERR_NOMORE_HANDLES       ERR_GENERAL-14

#define ERR_VFS_GENERAL          -3072
#define ERR_VFS_INVALID_FS       ERR_VFS_GENERAL-1
#define ERR_VFS_NOT_MOUNTPOINT   ERR_VFS_GENERAL-2
#define ERR_VFS_PATH_NOT_FOUND   ERR_VFS_GENERAL-3
#define ERR_VFS_INSUFFICIENT_BUF ERR_VFS_GENERAL-4
#define ERR_VFS_READONLY_FS      ERR_VFS_GENERAL-5
#define ERR_VFS_ALREADY_EXISTS   ERR_VFS_GENERAL-6
#define ERR_VFS_FS_BUSY          ERR_VFS_GENERAL-7
#define ERR_VFS_FD_TABLE_FULL    ERR_VFS_GENERAL-8
#define ERR_VFS_CROSS_FS_RENAME  ERR_VFS_GENERAL-9
#define ERR_VFS_DIR_NOT_EMPTY    ERR_VFS_GENERAL-10
#define ERR_VFS_NOT_DIR          ERR_VFS_GENERAL-11
#define ERR_VFS_WRONG_STREAM_TYPE   ERR_VFS_GENERAL-12
#define ERR_VFS_ALREADY_MOUNTPOINT ERR_VFS_GENERAL-13

The above are the most useful for the file system - we should either 
return or throw these.

If you like, I'll do the following functions:

//int sync(void);
//int open(const char *path, stream_type st, int omode);
//int close(int fd);
//int fsync(int fd);
//ssize_t read(int fd, void *buf, off_t pos, ssize_t len);
//ssize_t write(int fd, const void *buf, off_t pos, ssize_t len);
//int seek(int fd, off_t pos, seek_type seek_type);
//int ioctl(int fd, int op, void *buf, size_t len);
//int create(const char *path, stream_type stream_type);
//int unlink(const char *path);
//int rename(const char *oldpath, const char *newpath);

Also, rather than returning FILE* as fds, we could use an array (or 
vector) of structures and return the index of one of these - this is the 
system the kernel uses (and why you're limited to 256 open files per 
process in BeOS) .

Keith