Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753014Ab3JWQMI (ORCPT ); Wed, 23 Oct 2013 12:12:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:31441 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752507Ab3JWQL5 (ORCPT ); Wed, 23 Oct 2013 12:11:57 -0400 References: <87r4bcdok1.fsf@redhat.com> User-agent: mu4e 0.9.9.5; emacs 24.3.1 From: Madper Xie To: Richard Weinberger Cc: Madper Xie , "Luck\, Tony" , Anton Vorontsov , "linux-efi\@vger.kernel.org" , "linux-kernel\@vger.kernel.org" , Seiji Aguchi , Lenny Szubowicz , =?utf-8?B?5oiQ6aqPIOiwog==?= Subject: Re: [PATCH] pstore: avoid incorrectly mark entry as duplicate In-reply-to: Date: Thu, 24 Oct 2013 00:11:22 +0800 Message-ID: <87ob6g55n9.fsf@redhat.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2830 Lines: 71 richard.weinberger@gmail.com writes: > On Wed, Oct 23, 2013 at 4:55 PM, Madper Xie wrote: >> pstore try to find duplicate entries by check both ID, type and psi. >> They are not really enough for efi backend. dumped vars always have >> the same type, psi and ID. like follows: >> dump-type0-9-1-1382511508-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0 >> dump-type0-9-1-1382515661-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0 >> >> The "duplicate" entries won't appear in pstorefs. And a complain will be >> print -- pstore: failed to load 76 record(s) from 'efi' >> So I add one more check: timespec. >> >> Signed-off-by: Madper Xie >> --- >> fs/pstore/inode.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c >> index 1282384..f70f1e5 100644 >> --- a/fs/pstore/inode.c >> +++ b/fs/pstore/inode.c >> @@ -47,6 +47,7 @@ static LIST_HEAD(allpstore); >> struct pstore_private { >> struct list_head list; >> struct pstore_info *psi; >> + struct timespec time; >> enum pstore_type_id type; >> u64 id; >> int count; >> @@ -290,7 +291,8 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count, >> list_for_each_entry(pos, &allpstore, list) { >> if (pos->type == type && >> pos->id == id && >> - pos->psi == psi) { >> + pos->psi == psi && >> + !timespec_compare(&pos->time, &time)) { >> rc = -EEXIST; >> break; >> } >> @@ -312,6 +314,7 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count, >> private->id = id; >> private->count = count; >> private->psi = psi; >> + memcpy(&private->time, &time, sizeof(struct timespec)); >> >> switch (type) { >> case PSTORE_TYPE_DMESG: > > > As discussed on IRC, why don't you compare the variable names? Howdy Richard, Let's analyze the name of "duplicate" entries: >> dump-type0-9-1-1382511508-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0 >> dump-type0-9-1-1382515661-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0 The have the same name except timestamp. In this case, there is no difference between compare names and compare timestamps. ( Yeah, I'm pretty sure the guid will be the same one -- LINUX_EFI_CRASH_GUID ) But efi is only one backend. For other backends, we don't sure if they will add timestamp to name. So... -- Best, Madper Xie. -- 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/