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: "J. Bruce Fields" <bfields@citi.umich.edu>

diff --git a/fs/locks.c b/fs/locks.c
index 1a00b8b..957775b 100644 (file)
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -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;