From: Eric Sandeen Subject: Re: [PATCH] ext4: BUG_ON assertion repeated for inode1, not done for inode2 Date: Tue, 26 May 2015 15:44:24 -0500 Message-ID: <5564DB28.1050908@redhat.com> References: <5564B06E.6000604@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: linux-ext4@vger.kernel.org To: David Moore , tytso@mit.edu Return-path: Received: from mx1.redhat.com ([209.132.183.28]:36873 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752089AbbEZUoi (ORCPT ); Tue, 26 May 2015 16:44:38 -0400 In-Reply-To: <5564B06E.6000604@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On 5/26/15 12:42 PM, David Moore wrote: > During a source code review of fs/ext4/extents.c I noted identical > consecutive lines. An assertion is repeated for inode1 and never done > for inode2. This is not in keeping with the rest of the code in the > ext4_swap_extents function and appears to be a bug. > > Assert that the inode2 mutex is not locked. Yep, it's been that way since fcf6b1b ext4: refactor ext4_move_extents code base and it's pretty obviously not right as it is, and if there's any doubt the comments make it clear: + * Locking: + * i_mutex is held for both inodes + * i_data_sem is locked for write for both inodes Thanks, Reviewed-by: Eric Sandeen > Signed-off-by: David Moore > --- > fs/ext4/extents.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c > index e003a1e..f38a6d6 100644 > --- a/fs/ext4/extents.c > +++ b/fs/ext4/extents.c > @@ -5542,7 +5542,7 @@ ext4_swap_extents(handle_t *handle, struct inode *inode1, > BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem)); > BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem)); > BUG_ON(!mutex_is_locked(&inode1->i_mutex)); > - BUG_ON(!mutex_is_locked(&inode1->i_mutex)); > + BUG_ON(!mutex_is_locked(&inode2->i_mutex)); > > *erp = ext4_es_remove_extent(inode1, lblk1, count); > if (unlikely(*erp)) > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html