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>

1 files changed, 25 insertions, 24 deletions

diff --git a/fs/locks.c b/fs/locks.c
index 4e8cf5da2868..7d627ac0ed87 100644
--- 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;
         }