Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752225AbaFVMaV (ORCPT ); Sun, 22 Jun 2014 08:30:21 -0400 Received: from mail-we0-f176.google.com ([74.125.82.176]:53560 "EHLO mail-we0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751608AbaFVMaT (ORCPT ); Sun, 22 Jun 2014 08:30:19 -0400 From: Geert Uytterhoeven To: Miao Xie , Chris Mason , Josef Bacik Cc: linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH] Btrfs: Refactor btrfs_lock_cluster() to kill compiler warning Date: Sun, 22 Jun 2014 14:30:09 +0200 Message-Id: <1403440209-13370-1-git-send-email-geert@linux-m68k.org> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org fs/btrfs/extent-tree.c: In function ‘btrfs_lock_cluster’: fs/btrfs/extent-tree.c:6399: warning: ‘used_bg’ may be used uninitialized in this function - Replace "again: ... goto again;" by standard C "while (1) { ... }", - Move block not processed during the first iteration of the loop to the end of the loop, which allows to kill the "locked" variable, Signed-off-by: Geert Uytterhoeven --- Please review, compile tested only. --- fs/btrfs/extent-tree.c | 42 ++++++++++++++++++++---------------------- 1 file changed, 20 insertions(+), 22 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 99c253918208..e151c4a73d7b 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -6397,36 +6397,34 @@ btrfs_lock_cluster(struct btrfs_block_group_cache *block_group, int delalloc) { struct btrfs_block_group_cache *used_bg; - bool locked = false; -again: + spin_lock(&cluster->refill_lock); - if (locked) { - if (used_bg == cluster->block_group) - return used_bg; + while (1) { + used_bg = cluster->block_group; + if (!used_bg) + return NULL; - up_read(&used_bg->data_rwsem); - btrfs_put_block_group(used_bg); - } + if (used_bg == block_group) + return used_bg; - used_bg = cluster->block_group; - if (!used_bg) - return NULL; + btrfs_get_block_group(used_bg); - if (used_bg == block_group) - return used_bg; + if (!delalloc) + return used_bg; - btrfs_get_block_group(used_bg); + if (down_read_trylock(&used_bg->data_rwsem)) + return used_bg; - if (!delalloc) - return used_bg; + spin_unlock(&cluster->refill_lock); + down_read(&used_bg->data_rwsem); - if (down_read_trylock(&used_bg->data_rwsem)) - return used_bg; + spin_lock(&cluster->refill_lock); + if (used_bg == cluster->block_group) + return used_bg; - spin_unlock(&cluster->refill_lock); - down_read(&used_bg->data_rwsem); - locked = true; - goto again; + up_read(&used_bg->data_rwsem); + btrfs_put_block_group(used_bg); + } } static inline void -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/