From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH 2/2][RFC][BUG] msync: updating ctime and mtime at syncing From: Peter Zijlstra 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 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: 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 List-ID: 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org