locks: __break_lease cleanup in preparation of allowing direct removal of leases

Eliminate an unneeded "flock" variable. We can use "fl" as a loop cursor
everywhere. Add a any_leases_conflict helper function as well to
consolidate a bit of code.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

diff --git a/fs/locks.c b/fs/locks.c
index 4e8cf5da28689907b4b5c8b356325e4d7e498309..7d627ac0ed8724f934fb3df9691e2b03b5a2752d 100644 (file)
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1351,6 +1351,20 @@ static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker)
        return locks_conflict(breaker, lease);
 }
 
+static bool
+any_leases_conflict(struct inode *inode, struct file_lock *breaker)
+{
+       struct file_lock *fl;
+
+       lockdep_assert_held(&inode->i_lock);
+
+       for (fl = inode->i_flock ; fl && IS_LEASE(fl); fl = fl->fl_next) {
+               if (leases_conflict(fl, breaker))
+                       return true;
+       }
+       return false;
+}
+
 /**
  *     __break_lease   -       revoke all outstanding leases on file
  *     @inode: the inode of the file to return
@@ -1367,10 +1381,9 @@ static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker)
 int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
 {
        int error = 0;
-       struct file_lock *new_fl, *flock;
+       struct file_lock *new_fl;
        struct file_lock *fl;
        unsigned long break_time;
-       bool lease_conflict = false;
        int want_write = (mode & O_ACCMODE) != O_RDONLY;
        LIST_HEAD(dispose);
 
@@ -1383,17 +1396,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
 
        time_out_leases(inode, &dispose);
 
-       flock = inode->i_flock;
-       if ((flock == NULL) || !IS_LEASE(flock))
-               goto out;
-
-       for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) {
-               if (leases_conflict(fl, new_fl)) {
-                       lease_conflict = true;
-                       break;
-               }
-       }
-       if (!lease_conflict)
+       if (!any_leases_conflict(inode, new_fl))
                goto out;
 
        break_time = 0;
@@ -1403,7 +1406,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
                        break_time++;   /* so that 0 means no break time */
        }
 
-       for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) {
+       for (fl = inode->i_flock; fl && IS_LEASE(fl); fl = fl->fl_next) {
                if (!leases_conflict(fl, new_fl))
                        continue;
                if (want_write) {
@@ -1412,7 +1415,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
                        fl->fl_flags |= FL_UNLOCK_PENDING;
                        fl->fl_break_time = break_time;
                } else {
-                       if (lease_breaking(flock))
+                       if (lease_breaking(inode->i_flock))
                                continue;
                        fl->fl_flags |= FL_DOWNGRADE_PENDING;
                        fl->fl_downgrade_time = break_time;
@@ -1427,12 +1430,12 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
        }
 
 restart:
-       break_time = flock->fl_break_time;
+       break_time = inode->i_flock->fl_break_time;
        if (break_time != 0)
                break_time -= jiffies;
        if (break_time == 0)
                break_time++;
-       locks_insert_block(flock, new_fl);
+       locks_insert_block(inode->i_flock, new_fl);
        trace_break_lease_block(inode, new_fl);
        spin_unlock(&inode->i_lock);
        locks_dispose_list(&dispose);
@@ -1442,17 +1445,15 @@ restart:
        trace_break_lease_unblock(inode, new_fl);
        locks_delete_block(new_fl);
        if (error >= 0) {
-               if (error == 0)
-                       time_out_leases(inode, &dispose);
                /*
                 * Wait for the next conflicting lease that has not been
                 * broken yet
                 */
-               for (flock = inode->i_flock; flock && IS_LEASE(flock);
-                               flock = flock->fl_next) {
-                       if (leases_conflict(new_fl, flock))
-                               goto restart;
-               }
+               if (error == 0)
+                       time_out_leases(inode, &dispose);
+               if (any_leases_conflict(inode, new_fl))
+                       goto restart;
+
                error = 0;
        }