Commit c2fa1b8a authored by J. Bruce Fields's avatar J. Bruce Fields
Browse files

locks: create posix-to-flock helper functions 



Factor out a bit of messy code by creating posix-to-flock counterparts
to the existing flock-to-posix helper functions.

Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: default avatar"J. Bruce Fields" <bfields@citi.umich.edu>
parent 226a998d

fs/locks.c

+36 −25
Original line number Diff line number Diff line
@@ -1611,6 +1611,38 @@ asmlinkage long sys_flock(unsigned int fd, unsigned int cmd) 
	return error;

}



static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl)

{

	flock->l_pid = fl->fl_pid;

#if BITS_PER_LONG == 32

	/*

	 * Make sure we can represent the posix lock via

	 * legacy 32bit flock.

	 */

	if (fl->fl_start > OFFT_OFFSET_MAX)

		return -EOVERFLOW;

	if (fl->fl_end != OFFSET_MAX && fl->fl_end > OFFT_OFFSET_MAX)

		return -EOVERFLOW;

#endif

	flock->l_start = fl->fl_start;

	flock->l_len = fl->fl_end == OFFSET_MAX ? 0 :

		fl->fl_end - fl->fl_start + 1;

	flock->l_whence = 0;

	return 0;

}



#if BITS_PER_LONG == 32

static void posix_lock_to_flock64(struct flock64 *flock, struct file_lock *fl)

{

	flock->l_pid = fl->fl_pid;

	flock->l_start = fl->fl_start;

	flock->l_len = fl->fl_end == OFFSET_MAX ? 0 :

		fl->fl_end - fl->fl_start + 1;

	flock->l_whence = 0;

	flock->l_type = fl->fl_type;

}

#endif



/* Report the first existing lock that would conflict with l.

 * This implements the F_GETLK command of fcntl().

 */
@@ -1645,24 +1677,9 @@ int fcntl_getlk(struct file *filp, struct flock __user *l) 
 

	flock.l_type = F_UNLCK;

	if (fl != NULL) {

		flock.l_pid = fl->fl_pid;

#if BITS_PER_LONG == 32

		/*

		 * Make sure we can represent the posix lock via

		 * legacy 32bit flock.

		 */

		error = -EOVERFLOW;

		if (fl->fl_start > OFFT_OFFSET_MAX)

			goto out;

		if ((fl->fl_end != OFFSET_MAX)

		    && (fl->fl_end > OFFT_OFFSET_MAX))

		error = posix_lock_to_flock(&flock, fl);

		if (error)

			goto out;

#endif

		flock.l_start = fl->fl_start;

		flock.l_len = fl->fl_end == OFFSET_MAX ? 0 :

			fl->fl_end - fl->fl_start + 1;

		flock.l_whence = 0;

		flock.l_type = fl->fl_type;

	}

	error = -EFAULT;

	if (!copy_to_user(l, &flock, sizeof(flock)))
@@ -1798,14 +1815,8 @@ int fcntl_getlk64(struct file *filp, struct flock64 __user *l) 
	}

 

	flock.l_type = F_UNLCK;

	if (fl != NULL) {

		flock.l_pid = fl->fl_pid;

		flock.l_start = fl->fl_start;

		flock.l_len = fl->fl_end == OFFSET_MAX ? 0 :

			fl->fl_end - fl->fl_start + 1;

		flock.l_whence = 0;

		flock.l_type = fl->fl_type;

	}

	if (fl != NULL)

		posix_lock_to_flock64(&flock, fl);

	error = -EFAULT;

	if (!copy_to_user(l, &flock, sizeof(flock)))

		error = 0;