locks: factor out generic/filesystem switch from setlock code

Factor out the code that switches between generic and filesystem-specific lock
methods; eventually we want to call this from lock managers (lockd and nfsd)
too; currently they only call the generic methods.

This patch does that for all the setlk code.

Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>

2 files changed, 37 insertions, 32 deletions

diff --git a/fs/locks.c b/fs/locks.c
index a31648e3ec1b..f4fd1515b6e2 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1698,6 +1698,21 @@ out:
         return error;
 }
 
+/**
+ * vfs_lock_file - file byte range lock
+ * @filp: The file to apply the lock to
+ * @cmd: type of locking operation (F_SETLK, F_GETLK, etc.)
+ * @fl: The lock to be applied
+ */
+int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl)
+{
+        if (filp->f_op && filp->f_op->lock)
+                return filp->f_op->lock(filp, cmd, fl);
+        else
+                return posix_lock_file(filp, fl);
+}
+EXPORT_SYMBOL_GPL(vfs_lock_file);
+
 /* Apply the lock described by l to an open file descriptor.
  * This implements both the F_SETLK and F_SETLKW commands of fcntl().
  */
@@ -1760,21 +1775,17 @@ again:
         if (error)
                 goto out;
 
-        if (filp->f_op && filp->f_op->lock != NULL)
-                error = filp->f_op->lock(filp, cmd, file_lock);
-        else {
-                for (;;) {
-                        error = posix_lock_file(filp, file_lock);
-                        if (error != -EAGAIN || cmd == F_SETLK)
-                                break;
-                        error = wait_event_interruptible(file_lock->fl_wait,
-                                        !file_lock->fl_next);
-                        if (!error)
-                                continue;
-
-                        locks_delete_block(file_lock);
+        for (;;) {
+                error = vfs_lock_file(filp, cmd, file_lock);
+                if (error != -EAGAIN || cmd == F_SETLK)
                         break;
-                }
+                error = wait_event_interruptible(file_lock->fl_wait,
+                                !file_lock->fl_next);
+                if (!error)
+                        continue;
+
+                locks_delete_block(file_lock);
+                break;
         }
 
         /*
@@ -1890,21 +1901,17 @@ again:
         if (error)
                 goto out;
 
-        if (filp->f_op && filp->f_op->lock != NULL)
-                error = filp->f_op->lock(filp, cmd, file_lock);
-        else {
-                for (;;) {
-                        error = posix_lock_file(filp, file_lock);
-                        if (error != -EAGAIN || cmd == F_SETLK64)
-                                break;
-                        error = wait_event_interruptible(file_lock->fl_wait,
-                                        !file_lock->fl_next);
-                        if (!error)
-                                continue;
-
-                        locks_delete_block(file_lock);
+        for (;;) {
+                error = vfs_lock_file(filp, cmd, file_lock);
+                if (error != -EAGAIN || cmd == F_SETLK64)
                         break;
-                }
+                error = wait_event_interruptible(file_lock->fl_wait,
+                                !file_lock->fl_next);
+                if (!error)
+                        continue;
+
+                locks_delete_block(file_lock);
+                break;
         }
 
         /*
@@ -1949,10 +1956,7 @@ void locks_remove_posix(struct file *filp, fl_owner_t owner)
         lock.fl_ops = NULL;
         lock.fl_lmops = NULL;
 
-        if (filp->f_op && filp->f_op->lock != NULL)
-                filp->f_op->lock(filp, F_SETLK, &lock);
-        else
-                posix_lock_file(filp, &lock);
+        vfs_lock_file(filp, F_SETLK, &lock);
 
         if (lock.fl_ops && lock.fl_ops->fl_release_private)
                 lock.fl_ops->fl_release_private(&lock);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2a2a43988f50..1d5ccdd7c68d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -857,6 +857,7 @@ extern int posix_lock_file(struct file *, struct file_lock *);
 extern int posix_lock_file_wait(struct file *, struct file_lock *);
 extern int posix_unblock_lock(struct file *, struct file_lock *);
 extern int vfs_test_lock(struct file *, struct file_lock *);
+extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *);
 extern int flock_lock_file_wait(struct file *filp, struct file_lock *fl);
 extern int __break_lease(struct inode *inode, unsigned int flags);
 extern void lease_get_mtime(struct inode *, struct timespec *time);