50b06261b6
Implemented by changing write_map to accept a WMAP_FREE flag. In that case, it doesn't update the datablock (creating indirect zones as necessary) pointer, but it frees the datablock if present. Also it frees the single and double indirect blocks if unused. This makes the implementation of truncate_inode() simpler. truncate_inode() now accepts a truncation length which makes implementing truncate() and ftruncate() simple. This also allowed implementing the F_FREESP fcntl().
77 lines
3 KiB
C
Executable file
77 lines
3 KiB
C
Executable file
/* The <fcntl.h> header is needed by the open() and fcntl() system calls,
|
|
* which have a variety of parameters and flags. They are described here.
|
|
* The formats of the calls to each of these are:
|
|
*
|
|
* open(path, oflag [,mode]) open a file
|
|
* fcntl(fd, cmd [,arg]) get or set file attributes
|
|
*
|
|
*/
|
|
|
|
#ifndef _FCNTL_H
|
|
#define _FCNTL_H
|
|
|
|
#ifndef _TYPES_H
|
|
#include <sys/types.h>
|
|
#endif
|
|
|
|
/* These values are used for cmd in fcntl(). POSIX Table 6-1. */
|
|
#define F_DUPFD 0 /* duplicate file descriptor */
|
|
#define F_GETFD 1 /* get file descriptor flags */
|
|
#define F_SETFD 2 /* set file descriptor flags */
|
|
#define F_GETFL 3 /* get file status flags */
|
|
#define F_SETFL 4 /* set file status flags */
|
|
#define F_GETLK 5 /* get record locking information */
|
|
#define F_SETLK 6 /* set record locking information */
|
|
#define F_SETLKW 7 /* set record locking info; wait if blocked */
|
|
#define F_FREESP 8 /* free a section of a regular file */
|
|
|
|
/* File descriptor flags used for fcntl(). POSIX Table 6-2. */
|
|
#define FD_CLOEXEC 1 /* close on exec flag for third arg of fcntl */
|
|
|
|
/* L_type values for record locking with fcntl(). POSIX Table 6-3. */
|
|
#define F_RDLCK 1 /* shared or read lock */
|
|
#define F_WRLCK 2 /* exclusive or write lock */
|
|
#define F_UNLCK 3 /* unlock */
|
|
|
|
/* Oflag values for open(). POSIX Table 6-4. */
|
|
#define O_CREAT 00100 /* creat file if it doesn't exist */
|
|
#define O_EXCL 00200 /* exclusive use flag */
|
|
#define O_NOCTTY 00400 /* do not assign a controlling terminal */
|
|
#define O_TRUNC 01000 /* truncate flag */
|
|
|
|
/* File status flags for open() and fcntl(). POSIX Table 6-5. */
|
|
#define O_APPEND 02000 /* set append mode */
|
|
#define O_NONBLOCK 04000 /* no delay */
|
|
|
|
/* File access modes for open() and fcntl(). POSIX Table 6-6. */
|
|
#define O_RDONLY 0 /* open(name, O_RDONLY) opens read only */
|
|
#define O_WRONLY 1 /* open(name, O_WRONLY) opens write only */
|
|
#define O_RDWR 2 /* open(name, O_RDWR) opens read/write */
|
|
|
|
/* Mask for use with file access modes. POSIX Table 6-7. */
|
|
#define O_ACCMODE 03 /* mask for file access modes */
|
|
|
|
/* Struct used for locking. POSIX Table 6-8. */
|
|
struct flock {
|
|
short l_type; /* type: F_RDLCK, F_WRLCK, or F_UNLCK */
|
|
short l_whence; /* flag for starting offset */
|
|
off_t l_start; /* relative offset in bytes */
|
|
off_t l_len; /* size; if 0, then until EOF */
|
|
pid_t l_pid; /* process id of the locks' owner */
|
|
};
|
|
|
|
/* Function Prototypes. */
|
|
_PROTOTYPE( int creat, (const char *_path, _mnx_Mode_t _mode) );
|
|
_PROTOTYPE( int fcntl, (int _filedes, int _cmd, ...) );
|
|
_PROTOTYPE( int open, (const char *_path, int _oflag, ...) );
|
|
|
|
/* For locking files. */
|
|
#define LOCK_SH F_RDLCK /* Shared lock */
|
|
#define LOCK_EX F_WRLCK /* Exclusive lock */
|
|
#define LOCK_NB 0x0080 /* Do not block when locking */
|
|
#define LOCK_UN F_UNLCK /* Unlock */
|
|
|
|
_PROTOTYPE( int flock, (int fd, int mode) );
|
|
|
|
#endif /* _FCNTL_H */
|