Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762878AbYALJgG (ORCPT ); Sat, 12 Jan 2008 04:36:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759362AbYALJf4 (ORCPT ); Sat, 12 Jan 2008 04:35:56 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:58247 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758581AbYALJfz (ORCPT ); Sat, 12 Jan 2008 04:35:55 -0500 Subject: Re: [PATCH 2/2][RFC][BUG] msync: updating ctime and mtime at syncing From: Peter Zijlstra To: Anton Salikhmetov Cc: linux-mm@kvack.org, jakob@unthought.net, linux-kernel@vger.kernel.org, Valdis.Kletnieks@vt.edu, riel@redhat.com, ksm@42.dk, staubach@redhat.com, jesper.juhl@gmail.com In-Reply-To: <1200012249.20379.2.camel@codedot> References: <1200006638.19293.42.camel@codedot> <1200012249.20379.2.camel@codedot> Content-Type: text/plain Date: Sat, 12 Jan 2008 10:36:05 +0100 Message-Id: <1200130565.7999.8.camel@lappy> Mime-Version: 1.0 X-Mailer: Evolution 2.21.4 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1716 Lines: 65 On Fri, 2008-01-11 at 03:44 +0300, Anton Salikhmetov wrote: > +/* > + * Update the ctime and mtime stamps after checking if they are to be updated. > + */ > +void mapped_file_update_time(struct file *file) > +{ > + if (test_and_clear_bit(AS_MCTIME, &file->f_mapping->flags)) { > + get_file(file); > + file_update_time(file); > + fput(file); > + } > +} > + I don't think you need the get/put file stuff here, because > @@ -87,6 +87,8 @@ long do_fsync(struct file *file, int datasync) > goto out; > } > > + mapped_file_update_time(file); > + > ret = filemap_fdatawrite(mapping); > > /* at this call-site we already hold an extra reference on the file, and > @@ -74,14 +79,17 @@ asmlinkage long sys_msync(unsigned long start, size_t len, int flags) > break; > } > file = vma->vm_file; > - if ((flags & MS_SYNC) && file && (vma->vm_flags & VM_SHARED)) { > - get_file(file); > - up_read(&mm->mmap_sem); > - error = do_fsync(file, 0); > - fput(file); > - if (error) > - return error; > - down_read(&mm->mmap_sem); > + if (file && (vma->vm_flags & VM_SHARED)) { > + mapped_file_update_time(file); > + if (flags & MS_SYNC) { > + get_file(file); > + up_read(&mm->mmap_sem); > + error = do_fsync(file, 0); > + fput(file); > + if (error) > + return error; > + down_read(&mm->mmap_sem); > + } > } > > start = vma->vm_end; here we hold the mmap_sem so the vma reference on the file can't go away. -- 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/