From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f180.google.com (mail-pd0-f180.google.com [209.85.192.180]) by kanga.kvack.org (Postfix) with ESMTP id 158586B0038 for ; Fri, 3 Apr 2015 21:32:55 -0400 (EDT) Received: by pdea3 with SMTP id a3so86532580pde.3 for ; Fri, 03 Apr 2015 18:32:54 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id ze3si13987171pbc.209.2015.04.03.18.32.53 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 03 Apr 2015 18:32:53 -0700 (PDT) Date: Fri, 3 Apr 2015 18:35:40 -0700 From: Andrew Morton Subject: Re: [PATCH] mm/memory: print also a_ops->readpage in print_bad_pte Message-Id: <20150403183540.0ed5def0.akpm@linux-foundation.org> In-Reply-To: References: <20150403171818.22742.92919.stgit@buzz> <20150403151000.b51caa3f692358610fc1ca5d@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Konstantin Khlebnikov Cc: Konstantin Khlebnikov , "linux-mm@kvack.org" , Sasha Levin , Linux Kernel Mailing List On Sat, 4 Apr 2015 03:47:12 +0300 Konstantin Khlebnikov wrote: > On Sat, Apr 4, 2015 at 1:10 AM, Andrew Morton wrote: > > On Fri, 03 Apr 2015 20:18:18 +0300 Konstantin Khlebnikov wrote: > > > >> A lot of filesystems use generic_file_mmap() and filemap_fault(), > >> f_op->mmap and vm_ops->fault aren't enough to identify filesystem. > >> > >> This prints file name, vm_ops->fault, f_op->mmap and a_ops->readpage > >> (which is almost always implemented and filesystem-specific). > >> > >> Example: > >> > >> [ 23.676410] BUG: Bad page map in process sh pte:1b7e6025 pmd:19bbd067 > >> [ 23.676887] page:ffffea00006df980 count:4 mapcount:1 mapping:ffff8800196426c0 index:0x97 > >> [ 23.677481] flags: 0x10000000000000c(referenced|uptodate) > >> [ 23.677896] page dumped because: bad pte > >> [ 23.678205] addr:00007f52fcb17000 vm_flags:00000075 anon_vma: (null) mapping:ffff8800196426c0 index:97 > >> [ 23.678922] file:libc-2.19.so fault:filemap_fault mmap:generic_file_readonly_mmap readpage:v9fs_vfs_readpage > > > > Is that why we print these out? Just to identify the fs type? > > > > There's always vma->vm_file->f_inode->i_sb->s_magic ;) > > Yes, but that also might be anon inode/file mapped by some driver, so > s_magic isn't enough. Well, we could ensure that every file_system_type has a valid ->name. Do an audit, put a debug check in register_filesystem()? -- 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