fs/locks: merge posix_unblock_lock() and locks_delete_block()

posix_unblock_lock() is not specific to posix locks, and behaves
nearly identically to locks_delete_block() - the former returning a
status while the later doesn't.

So discard posix_unblock_lock() and use locks_delete_block() instead,
after giving that function an appropriate return value.

Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>

fs/cifs/file.c

@@ -1106,7 +1106,7 @@ cifs_posix_lock_set(struct file *file, struct file_lock *flock)
 		rc = wait_event_interruptible(flock->fl_wait, !flock->fl_blocker);
 		if (!rc)
 			goto try_again;
-		posix_unblock_lock(flock);
+		locks_delete_block(flock);
 	}
 	return rc;
 }

fs/lockd/svclock.c

@@ -276,7 +276,7 @@ static int nlmsvc_unlink_block(struct nlm_block *block)
 	dprintk("lockd: unlinking block %p...\n", block);
 
 	/* Remove block from list */
-	status = posix_unblock_lock(&block->b_call->a_args.lock.fl);
+	status = locks_delete_block(&block->b_call->a_args.lock.fl);
 	nlmsvc_remove_block(block);
 	return status;
 }

fs/locks.c

@@ -748,8 +748,16 @@ static void __locks_wake_up_blocks(struct file_lock *blocker)
 	}
 }
 
-static void locks_delete_block(struct file_lock *waiter)
+/**
+ *	locks_delete_lock - stop waiting for a file lock
+ *	@waiter: the lock which was waiting
+ *
+ *	lockd/nfsd need to disconnect the lock while working on it.
+ */
+int locks_delete_block(struct file_lock *waiter)
 {
+	int status = -ENOENT;
+
 	/*
 	 * If fl_blocker is NULL, it won't be set again as this thread
 	 * "owns" the lock and is the only one that might try to claim
@@ -763,12 +771,16 @@ static void locks_delete_block(struct file_lock *waiter)
 	 */
 	if (waiter->fl_blocker == NULL &&
 	    list_empty(&waiter->fl_blocked_requests))
-		return;
+		return status;
 	spin_lock(&blocked_lock_lock);
+	if (waiter->fl_blocker)
+		status = 0;
 	__locks_wake_up_blocks(waiter);
 	__locks_delete_block(waiter);
 	spin_unlock(&blocked_lock_lock);
+	return status;
 }
+EXPORT_SYMBOL(locks_delete_block);
 
 /* Insert waiter into blocker's block list.
  * We use a circular list so that processes can be easily woken up in
@@ -2675,28 +2687,6 @@ void locks_remove_file(struct file *filp)
 	spin_unlock(&ctx->flc_lock);
 }
 
-/**
- *	posix_unblock_lock - stop waiting for a file lock
- *	@waiter: the lock which was waiting
- *
- *	lockd needs to block waiting for locks.
- */
-int
-posix_unblock_lock(struct file_lock *waiter)
-{
-	int status = -ENOENT;
-
-	spin_lock(&blocked_lock_lock);
-	if (waiter->fl_blocker) {
-		__locks_wake_up_blocks(waiter);
-		__locks_delete_block(waiter);
-		status = 0;
-	}
-	spin_unlock(&blocked_lock_lock);
-	return status;
-}
-EXPORT_SYMBOL(posix_unblock_lock);
-
 /**
  * vfs_cancel_lock - file byte range unblock lock
  * @filp: The file to apply the unblock to

fs/nfsd/nfs4state.c

@@ -238,7 +238,7 @@ find_blocked_lock(struct nfs4_lockowner *lo, struct knfsd_fh *fh,
 	}
 	spin_unlock(&nn->blocked_locks_lock);
 	if (found)
-		posix_unblock_lock(&found->nbl_lock);
+		locks_delete_block(&found->nbl_lock);
 	return found;
 }
 
@@ -293,7 +293,7 @@ remove_blocked_locks(struct nfs4_lockowner *lo)
 		nbl = list_first_entry(&reaplist, struct nfsd4_blocked_lock,
 					nbl_lru);
 		list_del_init(&nbl->nbl_lru);
-		posix_unblock_lock(&nbl->nbl_lock);
+		locks_delete_block(&nbl->nbl_lock);
 		free_blocked_lock(nbl);
 	}
 }
@@ -4863,7 +4863,7 @@ nfs4_laundromat(struct nfsd_net *nn)
 		nbl = list_first_entry(&reaplist,
 					struct nfsd4_blocked_lock, nbl_lru);
 		list_del_init(&nbl->nbl_lru);
-		posix_unblock_lock(&nbl->nbl_lock);
+		locks_delete_block(&nbl->nbl_lock);
 		free_blocked_lock(nbl);
 	}
 out:

include/linux/fs.h

@@ -1124,7 +1124,7 @@ extern void locks_remove_file(struct file *);
 extern void locks_release_private(struct file_lock *);
 extern void posix_test_lock(struct file *, struct file_lock *);
 extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *);
-extern int posix_unblock_lock(struct file_lock *);
+extern int locks_delete_block(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 *, struct file_lock *);
 extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl);
@@ -1214,7 +1214,7 @@ static inline int posix_lock_file(struct file *filp, struct file_lock *fl,
 	return -ENOLCK;
 }
 
-static inline int posix_unblock_lock(struct file_lock *waiter)
+static inline int locks_delete_block(struct file_lock *waiter)
 {
 	return -ENOENT;
 }