locks: setlease cleanup

There's an incorrect comment here.  Also clean up the logic: the
"rdlease" and "wrlease" locals are confusingly named, and don't really
add anything since we can make a decision as soon as we hit one of these
cases.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/locks.c b/fs/locks.c
index c525aa4de234827c1e59960b7e0e280c8a37246a..9b8408eb69463b62a39ffe9d7d602a588d1626ec 100644 (file)
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1368,7 +1368,7 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
        struct file_lock *fl, **before, **my_before = NULL, *lease;
        struct dentry *dentry = filp->f_path.dentry;
        struct inode *inode = dentry->d_inode;
-       int error, rdlease_count = 0, wrlease_count = 0;
+       int error;
 
        lease = *flp;
 
@@ -1404,27 +1404,28 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
         * then the file is not open by anyone (including us)
         * except for this filp.
         */
+       error = -EAGAIN;
        for (before = &inode->i_flock;
                        ((fl = *before) != NULL) && IS_LEASE(fl);
                        before = &fl->fl_next) {
-               if (fl->fl_file == filp)
+               if (fl->fl_file == filp) {
                        my_before = before;
-               else if (fl->fl_flags & FL_UNLOCK_PENDING)
-                       /*
-                        * Someone is in the process of opening this
-                        * file for writing so we may not take an
-                        * exclusive lease on it.
-                        */
-                       wrlease_count++;
-               else
-                       rdlease_count++;
+                       continue;
+               }
+               /*
+                * No exclusive leases if someone else has a lease on
+                * this file:
+                */
+               if (arg == F_WRLCK)
+                       goto out;
+               /*
+                * Modifying our existing lease is OK, but no getting a
+                * new lease if someone else is opening for write:
+                */
+               if (fl->fl_flags & FL_UNLOCK_PENDING)
+                       goto out;
        }
 
-       error = -EAGAIN;
-       if ((arg == F_RDLCK && (wrlease_count > 0)) ||
-           (arg == F_WRLCK && ((rdlease_count + wrlease_count) > 0)))
-               goto out;
-
        if (my_before != NULL) {
                error = lease->fl_lmops->lm_change(my_before, arg);
                if (!error)