linux-master/fs/locks.c

7  * see the flock(2) man page; for details about the other three, see
12  * If multiple threads attempt to lock the same byte (or flock the same file)
538 /* Verify a "struct flock" and copy it to a "struct file_lock" as a POSIX
542 			       struct flock *l)
2117  *	sys_flock: - flock() system call.
2127  *	- %LOCK_MAND -- a 'mandatory' flock. (DEPRECATED)
2131 SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd)
2146 		pr_warn_once("%s(%d): Attempt to set a LOCK_MAND lock via flock(2). This support has been removed and the request ignored.\n", current->comm, current->pid);
2172 	if (f.file->f_op->flock)
2173 		error = f.file->f_op->flock(f.file,
2224 	 * If the flock owner process is dead and its pid has been already
2226 	 * flock owner pid number in init pidns.
2238 static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl)
2240 	flock->l_pid = locks_translate_pid(&fl->c, task_active_pid_ns(current));
2244 	 * legacy 32bit flock.
2251 	flock->l_start = fl->fl_start;
2252 	flock->l_len = fl->fl_end == OFFSET_MAX ? 0 :
2254 	flock->l_whence = 0;
2255 	flock->l_type = fl->c.flc_type;
2260 static void posix_lock_to_flock64(struct flock64 *flock, struct file_lock *fl)
2262 	flock->l_pid = locks_translate_pid(&fl->c, task_active_pid_ns(current));
2263 	flock->l_start = fl->fl_start;
2264 	flock->l_len = fl->fl_end == OFFSET_MAX ? 0 :
2266 	flock->l_whence = 0;
2267 	flock->l_type = fl->c.flc_type;
2274 int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock *flock)
2283 	if (cmd != F_OFD_GETLK && flock->l_type != F_RDLCK
2284 			&& flock->l_type != F_WRLCK)
2287 	error = flock_to_posix_lock(filp, fl, flock);
2293 		if (flock->l_pid != 0)
2304 	flock->l_type = fl->c.flc_type;
2306 		error = posix_lock_to_flock(flock, fl);
2403 		struct flock *flock)
2413 	error = flock_to_posix_lock(filp, file_lock, flock);
2428 		if (flock->l_pid != 0)
2437 		if (flock->l_pid != 0)
2483 int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 *flock)
2493 	if (cmd != F_OFD_GETLK && flock->l_type != F_RDLCK
2494 			&& flock->l_type != F_WRLCK)
2497 	error = flock64_to_posix_lock(filp, fl, flock);
2503 		if (flock->l_pid != 0)
2514 	flock->l_type = fl->c.flc_type;
2516 		posix_lock_to_flock64(flock, fl);
2527 		struct flock64 *flock)
2536 	error = flock64_to_posix_lock(filp, file_lock, flock);
2551 		if (flock->l_pid != 0)
2560 		if (flock->l_pid != 0)
2655 	if (filp->f_op->flock)
2656 		filp->f_op->flock(filp, F_SETLKW, &fl);
2699 	/* remove flock locks */