From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF6AEC43144 for ; Sat, 23 Jun 2018 08:12:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9C84924B6A for ; Sat, 23 Jun 2018 08:12:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9C84924B6A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751794AbeFWIM0 (ORCPT ); Sat, 23 Jun 2018 04:12:26 -0400 Received: from mx2.suse.de ([195.135.220.15]:34448 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751742AbeFWIMV (ORCPT ); Sat, 23 Jun 2018 04:12:21 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext-too.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id F1DCBAEDA; Sat, 23 Jun 2018 08:12:19 +0000 (UTC) Subject: Re: [PATCH] [v2] bcache: stop using the deprecated get_seconds() To: Arnd Bergmann Cc: Kent Overstreet , y2038@lists.linaro.org, Jens Axboe , Michael Lyle , Tang Junhui , Hannes Reinecke , linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org References: <20180622134907.227131-1-arnd@arndb.de> From: Coly Li Openpgp: preference=signencrypt Autocrypt: addr=colyli@suse.de; prefer-encrypt=mutual; keydata= xsFNBFYX6S8BEAC9VSamb2aiMTQREFXK4K/W7nGnAinca7MRuFUD4JqWMJ9FakNRd/E0v30F qvZ2YWpidPjaIxHwu3u9tmLKqS+2vnP0k7PRHXBYbtZEMpy3kCzseNfdrNqwJ54A430BHf2S GMVRVENiScsnh4SnaYjFVvB8SrlhTsgVEXEBBma5Ktgq9YSoy5miatWmZvHLFTQgFMabCz/P j5/xzykrF6yHo0rHZtwzQzF8rriOplAFCECp/t05+OeHHxjSqSI0P/G79Ll+AJYLRRm9til/ K6yz/1hX5xMToIkYrshDJDrUc8DjEpISQQPhG19PzaUf3vFpmnSVYprcWfJWsa2wZyyjRFkf J51S82WfclafNC6N7eRXedpRpG6udUAYOA1YdtlyQRZa84EJvMzW96iSL1Gf+ZGtRuM3k49H 1wiWOjlANiJYSIWyzJjxAd/7Xtiy/s3PRKL9u9y25ftMLFa1IljiDG+mdY7LyAGfvdtIkanr iBpX4gWXd7lNQFLDJMfShfu+CTMCdRzCAQ9hIHPmBeZDJxKq721CyBiGAhRxDN+TYiaG/UWT 7IB7LL4zJrIe/xQ8HhRO+2NvT89o0LxEFKBGg39yjTMIrjbl2ZxY488+56UV4FclubrG+t16 r2KrandM7P5RjR+cuHhkKseim50Qsw0B+Eu33Hjry7YCihmGswARAQABzRhDb2x5IExpIDxj b2x5bGlAc3VzZS5kZT7CwX8EEwEIACkFAlYX6ZACGyMFCQlmAYAHCwkIBwMCAQYVCAIJCgsE FgIDAQIeAQIXgAAKCRDHOQeTa334/CncD/9B97EIjcDOm0TS164bpMlsbZWEm8GQnV6nVzm8 QsywPRM8S8nqkqX1atTYl/fTdJsasH8mgryUqL0eHBPs5RmJhDk3YgYsTrzbOjMdsdRwv24W J5RXdulRag2XDPIhSP7rWsOSh66gljdAp8XQQZD0zFXi4IytoAuLtx8RMjzzKk1iP6uz8MIv em7iFu6NYcHd3cmvSPo7CnBVaG0dZ6P2p2gS7ydSWOGsWkNh/XM4ojJaX1ZdCeFR0XLS76Gi 6e01DoN2UsqZE/TQu1czYMMA1uM/Es6ZTYgobTrrnNB79ctqgtbBrjME5sOHLX40ccbBI3QB Ta4opSp8VqUMXw/yd5ckLPocnkJBTVxuaOfRhpxr6gWeudrkMetMj+39yeklskP7up0JvAUG 7/HjjqwWR7xAaZHmZORYsIxJ9ploBb8eSqHHx+7489ZDNLP+WCsAonpKTdJNAzGJClnLFxKS DY4cOPs7o4IFBk6dVXJWMqyLGwmMQ51Pq6BID4epaAuuBAL6x7n7NrFPuS68Fn/VaxqMEld9 L2eCi4cv++1AJyMF3iQKT56I8BjHEuf0wo1tmZ3BgBT19xRsEl7YItixxtYQm66Pb4lSQQmE Ep+uQNwaqPpeAU+vkDg/0Q+dhPTsvwx0OAI30HwhuzNA8OIfHBx7dJNm0b0fg5x0pg3LDM7B TQRWF+kvARAA2T/tnJeA0RWkmgZrNPFvP7JnOU9gjmIQKMoGZ+9awew45pdmXb6y0Y0fEG59 EP9i9oBlFXOt6SZ2645V0sdi3wBRNEpX2CCddWhXRfcO0b6lgckIwyaK92dH1rzxMaZTYDL8 aQ9FNEK1U+XSBk8fYWnXowpf7oNPS6+jD0J/muPqrGkVsIAkh2iLg5B98yNTCV4ql1xSlMyf xcseke9q6ojDxx9p38JjLusDlwF2+/rF42c+T6PRiYNjnBHPq6VLSlCRsnkLJwg8VHKiV2Qw Yvxp4TwnK2kLqokOxBlriX45Odb2iP61uG2ZAPchDwfawWJ4G8+3EMplLH8bk0/DkpYcYz95 eGSGRSiIQ2kHmTI/KbpgXxFVMoheilUn4HzUP+T6TEeP6Zhm0aqwABJYa0T2ykJwpBlg6/Mx vgIzdSheqx2hYACDu07WfhdvI6uK3i5Lq9DebUBcMMBcMc0TnXix7mYy+3hLXJzZ80pFx3My 5FeJEN/r6/+xpuuZkH51aYOiacKVa2w2EHjhZcWfPhhEWOQ2oOCoCmv+HEmV9sf+fipEMfcB 8GnJMOYAwrwHWfkPNZ5urUcRGAQYlQ0GWKju97LYE2cq5McpFG0CMvDyPoO1zAwjJz4g53EK oH/eikd3L8OMDfEK4AOsUaPMTnNgt1+40zEFMrQs/dDMldUAEQEAAcLBZQQYAQgADwUCVhfp LwIbDAUJCWYBgAAKCRDHOQeTa334/PtREACDN8W/pHeHyPW/mTt6MEe/GICG5YdlBW5ft7HY Cf6rTz+uLZolGc5SYKuJJ0JC/L2Ifh3BWmwLIOxV868KB3oEfmGszBY+4n/icLyIEAkkthBb 2V5sP5KgB3bOg7mSFBxfHi2pyO9K9d+Lr+UkORjCGyV33QFrcN+OQdPDactontnQglB7xm2K phGWqxoqepHCqFIulZ3yKGhQhmdpyz0J19Ry6GkxPE85MG/NC98D5+4Yn/V3G+yZpbGsuFhE CP26JvdXh1jNCUdU46pEjZwu0GXBIo6r1cb1v+swfYB86NeFUHWtvxamh8i6RBl1FLDhN6xb r9f7M++xoADyzPQYQPQUxWK+iG6lz3qVVq5312z/is3fcdyESPNs09DMT43xCCBr9UOMq6dZ IC9EsSeMYv4librfuSRqH4R0MuVbVWLJFg/Q7s+nbPb2YjhqIYr51hBDyXpzUDoIz43maIPk UmCNKa43mNFktMrwU21J5lVXEwBuTY6JlHOAl0Fgo28X+eTa8fx2Uiz9OVgWe03ebJGIGowe XTgqVWJMsKM1tmW+QFmgtczDGRYCZ6OQYpqt0SoTg1yx5MN4RzUtlLka2qLfPiOGUUN3qNJ5 nP+spvF+s+dHtLjjhy7AL86N01a6S0rwaClVVv0XTucvIntwccIx0CZfUKlfn5BWnB64Ig== Message-ID: Date: Sat, 23 Jun 2018 16:12:10 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20180622134907.227131-1-arnd@arndb.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018/6/22 9:48 PM, Arnd Bergmann wrote: > The get_seconds function is deprecated now since it returns a 32-bit > value that will eventually overflow, and we are replacing it throughout > the kernel with ktime_get_seconds() or ktime_get_real_seconds() that > return a time64_t. > > bcache uses get_seconds() to read the current system time and store it in > the superblock as well as in uuid_entry structures that are user visible. > > Unfortunately, the two structures in are still limited to 32 bits, so this > won't fix any real problems but will still overflow in year 2106. Let's > at least document that properly, in case we get an updated format in the > future it can be fixed. We still have a long time before the overflow > and checking the tools at https://github.com/koverstreet/bcache-tools > reveals no access to any of them. > > Signed-off-by: Arnd Bergmann Added to 4.19 for-next. Thanks. Coly Li > --- > drivers/md/bcache/super.c | 12 ++++++------ > include/uapi/linux/bcache.h | 4 ++-- > 2 files changed, 8 insertions(+), 8 deletions(-) > > diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c > index fa4058e43202..74746d8ee05e 100644 > --- a/drivers/md/bcache/super.c > +++ b/drivers/md/bcache/super.c > @@ -181,7 +181,7 @@ static const char *read_super(struct cache_sb *sb, struct block_device *bdev, > goto err; > } > > - sb->last_mount = get_seconds(); > + sb->last_mount = (u32)ktime_get_real_seconds(); > err = NULL; > > get_page(bh->b_page); > @@ -701,7 +701,7 @@ static void bcache_device_detach(struct bcache_device *d) > > SET_UUID_FLASH_ONLY(u, 0); > memcpy(u->uuid, invalid_uuid, 16); > - u->invalidated = cpu_to_le32(get_seconds()); > + u->invalidated = cpu_to_le32((u32)ktime_get_real_seconds()); > bch_uuid_write(d->c); > } > > @@ -1027,7 +1027,7 @@ void bch_cached_dev_detach(struct cached_dev *dc) > int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c, > uint8_t *set_uuid) > { > - uint32_t rtime = cpu_to_le32(get_seconds()); > + uint32_t rtime = cpu_to_le32((u32)ktime_get_real_seconds()); > struct uuid_entry *u; > struct cached_dev *exist_dc, *t; > > @@ -1070,7 +1070,7 @@ int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c, > (BDEV_STATE(&dc->sb) == BDEV_STATE_STALE || > BDEV_STATE(&dc->sb) == BDEV_STATE_NONE)) { > memcpy(u->uuid, invalid_uuid, 16); > - u->invalidated = cpu_to_le32(get_seconds()); > + u->invalidated = cpu_to_le32((u32)ktime_get_real_seconds()); > u = NULL; > } > > @@ -1390,7 +1390,7 @@ int bch_flash_dev_create(struct cache_set *c, uint64_t size) > > get_random_bytes(u->uuid, 16); > memset(u->label, 0, 32); > - u->first_reg = u->last_reg = cpu_to_le32(get_seconds()); > + u->first_reg = u->last_reg = cpu_to_le32((u32)ktime_get_real_seconds()); > > SET_UUID_FLASH_ONLY(u, 1); > u->sectors = size >> 9; > @@ -1894,7 +1894,7 @@ static void run_cache_set(struct cache_set *c) > goto err; > > closure_sync(&cl); > - c->sb.last_mount = get_seconds(); > + c->sb.last_mount = (u32)ktime_get_real_seconds(); > bcache_write_super(c); > > list_for_each_entry_safe(dc, t, &uncached_devices, list) > diff --git a/include/uapi/linux/bcache.h b/include/uapi/linux/bcache.h > index 821f71a2e48f..8d19e02d752a 100644 > --- a/include/uapi/linux/bcache.h > +++ b/include/uapi/linux/bcache.h > @@ -195,7 +195,7 @@ struct cache_sb { > }; > }; > > - __u32 last_mount; /* time_t */ > + __u32 last_mount; /* time overflow in y2106 */ > > __u16 first_bucket; > union { > @@ -318,7 +318,7 @@ struct uuid_entry { > struct { > __u8 uuid[16]; > __u8 label[32]; > - __u32 first_reg; > + __u32 first_reg; /* time overflow in y2106 */ > __u32 last_reg; > __u32 invalidated; > >