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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 94347C76192 for ; Wed, 17 Jul 2019 02:58:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6AFB42173E for ; Wed, 17 Jul 2019 02:58:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727753AbfGQC6a (ORCPT ); Tue, 16 Jul 2019 22:58:30 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:33822 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725892AbfGQC6a (ORCPT ); Tue, 16 Jul 2019 22:58:30 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 8921F6D12B92184B869F; Wed, 17 Jul 2019 10:58:27 +0800 (CST) Received: from [10.134.22.195] (10.134.22.195) by smtp.huawei.com (10.3.19.206) with Microsoft SMTP Server (TLS) id 14.3.439.0; Wed, 17 Jul 2019 10:58:17 +0800 Subject: Re: [RFC PATCH] iomap: generalize IOMAP_INLINE to cover tail-packing case From: Chao Yu To: Andreas Gruenbacher CC: Christoph Hellwig , "Darrick J. Wong" , , linux-fsdevel , Gao Xiang , References: <20190703075502.79782-1-yuchao0@huawei.com> <39944e50-5888-f900-1954-91be2b12ea5b@huawei.com> <20190711122831.3970-1-agruenba@redhat.com> <164e33fc-783c-3c35-6aa7-43c21b12ccb7@huawei.com> Message-ID: <90fca1c4-c142-992d-ebf3-03c8017f95b7@huawei.com> Date: Wed, 17 Jul 2019 10:58:15 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <164e33fc-783c-3c35-6aa7-43c21b12ccb7@huawei.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.134.22.195] X-CFilter-Loop: Reflected Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Ping, Andreas. :P On 2019/7/15 17:26, Chao Yu wrote: > On 2019/7/12 19:54, Andreas Gruenbacher wrote: >> On Fri, 12 Jul 2019 at 11:31, Chao Yu wrote: >>> On 2019/7/11 20:28, Andreas Gruenbacher wrote: >>>> Something along the lines of the attached, broken patch might work in >>>> the end. >>>> >>>> Andreas >>>> >>>> --- >>>> fs/buffer.c | 10 ++++-- >>>> fs/iomap.c | 74 +++++++++++++++++++++++++++++-------------- >>>> include/linux/iomap.h | 3 ++ >>>> 3 files changed, 61 insertions(+), 26 deletions(-) >>>> >>>> diff --git a/fs/buffer.c b/fs/buffer.c >>>> index e450c55f6434..8d8668e377ab 100644 >>>> --- a/fs/buffer.c >>>> +++ b/fs/buffer.c >>>> @@ -1873,8 +1873,8 @@ void page_zero_new_buffers(struct page *page, unsigned from, unsigned to) >>>> EXPORT_SYMBOL(page_zero_new_buffers); >>>> >>>> static void >>>> -iomap_to_bh(struct inode *inode, sector_t block, struct buffer_head *bh, >>>> - struct iomap *iomap) >>>> +iomap_to_bh(struct inode *inode, struct page *page, sector_t block, >>>> + struct buffer_head *bh, struct iomap *iomap) >>>> { >>>> loff_t offset = block << inode->i_blkbits; >>>> >>>> @@ -1924,6 +1924,10 @@ iomap_to_bh(struct inode *inode, sector_t block, struct buffer_head *bh, >>>> inode->i_blkbits; >>>> set_buffer_mapped(bh); >>>> break; >>>> + case IOMAP_INLINE: >>>> + __iomap_read_inline_data(inode, page, iomap); >>>> + set_buffer_uptodate(bh); >>>> + break; >>>> } >>>> } >>>> >>>> @@ -1969,7 +1973,7 @@ int __block_write_begin_int(struct page *page, loff_t pos, unsigned len, >>>> if (err) >>>> break; >>>> } else { >>>> - iomap_to_bh(inode, block, bh, iomap); >>>> + iomap_to_bh(inode, page, block, bh, iomap); >>>> } >>>> >>>> if (buffer_new(bh)) { >>>> diff --git a/fs/iomap.c b/fs/iomap.c >>>> index 45aa58e837b5..61188e95def2 100644 >>>> --- a/fs/iomap.c >>>> +++ b/fs/iomap.c >>>> @@ -260,24 +260,47 @@ struct iomap_readpage_ctx { >>>> struct list_head *pages; >>>> }; >>>> >>>> -static void >>>> -iomap_read_inline_data(struct inode *inode, struct page *page, >>>> +#define offset_in_block(offset, inode) \ >>>> + ((unsigned long)(offset) & (i_blocksize(inode) - 1)) >>>> + >>>> +static bool >>>> +inline_data_within_block(struct inode *inode, struct iomap *iomap, >>>> + unsigned int size) >>>> +{ >>>> + unsigned int off = offset_in_block(iomap->inline_data, inode); >>>> + >>>> + return size <= i_blocksize(inode) - off; >>>> +} >>>> + >>>> +void >>>> +__iomap_read_inline_data(struct inode *inode, struct page *page, >>>> struct iomap *iomap) >>>> { >>>> - size_t size = i_size_read(inode); >>>> + size_t size = offset_in_block(i_size_read(inode), inode); >>>> + unsigned int poff = offset_in_page(iomap->offset); >>>> + unsigned int bsize = i_blocksize(inode); >>>> void *addr; >>>> >>>> if (PageUptodate(page)) >>>> return; >>>> >>>> - BUG_ON(page->index); >>>> - BUG_ON(size > PAGE_SIZE - offset_in_page(iomap->inline_data)); >>>> + BUG_ON(!inline_data_within_block(inode, iomap, size)); >>>> >>>> addr = kmap_atomic(page); >>>> - memcpy(addr, iomap->inline_data, size); >>>> - memset(addr + size, 0, PAGE_SIZE - size); >>>> + memcpy(addr + poff, iomap->inline_data, size); >>>> + memset(addr + poff + size, 0, bsize - size); >>>> kunmap_atomic(addr); >>>> - SetPageUptodate(page); >>>> +} >>>> + >>>> +static void >>>> +iomap_read_inline_data(struct inode *inode, struct page *page, >>>> + struct iomap *iomap) >>>> +{ >>>> + unsigned int poff = offset_in_page(iomap->offset); >>>> + unsigned int bsize = i_blocksize(inode); >>>> + >>>> + __iomap_read_inline_data(inode, page, iomap); >>>> + iomap_set_range_uptodate(page, poff, bsize); >>>> } >>>> >>>> static loff_t >>>> @@ -292,11 +315,8 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, >>>> unsigned poff, plen; >>>> sector_t sector; >>>> >>>> - if (iomap->type == IOMAP_INLINE) { >>>> - WARN_ON_ONCE(pos); >>>> + if (iomap->type == IOMAP_INLINE) >>>> iomap_read_inline_data(inode, page, iomap); >>>> - return PAGE_SIZE; >>> >>> Hi Andreas, >>> >>> Thanks for your patch. >>> >>> In my erofs test case, filled inline data will be zeroed out due to we fallback >>> to following flow: >>> >>> if (iomap->type != IOMAP_MAPPED || pos >= i_size_read(inode)) { >>> zero_user(page, poff, plen); >>> >>> Should we return before this condition check? >> >> Yes, probably by returning i_blocksize(inode) after >> iomap_read_inline_data, but that alone isn't enough to make the patch > > Could you please resend this diff as a new patch with above fix? > >> work completely. This really needs a review from Christoph and careful >> testing of all the code paths. > > Later, I can do the test on read path. > > Thanks, > >> >> Andreas >> >>> Thanks, >>> >>>> - } >>>> >>>> /* zero post-eof blocks as the page may be mapped */ >>>> iomap_adjust_read_range(inode, iop, &pos, length, &poff, &plen); >>>> @@ -637,6 +657,11 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, >>>> if (PageUptodate(page)) >>>> return 0; >>>> >>>> + if (iomap->type == IOMAP_INLINE) { >>>> + iomap_read_inline_data(inode, page, iomap); >>>> + return 0; >>>> + } >>>> + >>>> do { >>>> iomap_adjust_read_range(inode, iop, &block_start, >>>> block_end - block_start, &poff, &plen); >>>> @@ -682,9 +707,7 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, >>>> goto out_no_page; >>>> } >>>> >>>> - if (iomap->type == IOMAP_INLINE) >>>> - iomap_read_inline_data(inode, page, iomap); >>>> - else if (iomap->flags & IOMAP_F_BUFFER_HEAD) >>>> + if (iomap->flags & IOMAP_F_BUFFER_HEAD) >>>> status = __block_write_begin_int(page, pos, len, NULL, iomap); >>>> else >>>> status = __iomap_write_begin(inode, pos, len, page, iomap); >>>> @@ -761,11 +784,11 @@ iomap_write_end_inline(struct inode *inode, struct page *page, >>>> { >>>> void *addr; >>>> >>>> - WARN_ON_ONCE(!PageUptodate(page)); >>>> - BUG_ON(pos + copied > PAGE_SIZE - offset_in_page(iomap->inline_data)); >>>> + BUG_ON(!inline_data_within_block(inode, iomap, pos + copied)); >>>> >>>> addr = kmap_atomic(page); >>>> - memcpy(iomap->inline_data + pos, addr + pos, copied); >>>> + memcpy(iomap->inline_data + offset_in_block(pos, inode), >>>> + addr + offset_in_page(pos), copied); >>>> kunmap_atomic(addr); >>>> >>>> mark_inode_dirty(inode); >>>> @@ -1064,7 +1087,7 @@ iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, >>>> const struct iomap_ops *ops) >>>> { >>>> unsigned int blocksize = i_blocksize(inode); >>>> - unsigned int off = pos & (blocksize - 1); >>>> + unsigned int off = offset_in_block(pos, inode); >>>> >>>> /* Block boundary? Nothing to do */ >>>> if (!off) >>>> @@ -1772,21 +1795,26 @@ iomap_dio_inline_actor(struct inode *inode, loff_t pos, loff_t length, >>>> struct iov_iter *iter = dio->submit.iter; >>>> size_t copied; >>>> >>>> - BUG_ON(pos + length > PAGE_SIZE - offset_in_page(iomap->inline_data)); >>>> + BUG_ON(!inline_data_within_block(inode, iomap, pos + length)); >>>> >>>> if (dio->flags & IOMAP_DIO_WRITE) { >>>> loff_t size = inode->i_size; >>>> >>>> if (pos > size) >>>> - memset(iomap->inline_data + size, 0, pos - size); >>>> - copied = copy_from_iter(iomap->inline_data + pos, length, iter); >>>> + memset(iomap->inline_data + >>>> + offset_in_block(size, inode), 0, pos - size); >>>> + copied = copy_from_iter(iomap->inline_data + >>>> + offset_in_block(pos, inode), >>>> + length, iter); >>>> if (copied) { >>>> if (pos + copied > size) >>>> i_size_write(inode, pos + copied); >>>> mark_inode_dirty(inode); >>>> } >>>> } else { >>>> - copied = copy_to_iter(iomap->inline_data + pos, length, iter); >>>> + copied = copy_to_iter(iomap->inline_data + >>>> + offset_in_block(pos, inode), >>>> + length, iter); >>>> } >>>> dio->size += copied; >>>> return copied; >>>> diff --git a/include/linux/iomap.h b/include/linux/iomap.h >>>> index 2103b94cb1bf..a8a60dd2fdc0 100644 >>>> --- a/include/linux/iomap.h >>>> +++ b/include/linux/iomap.h >>>> @@ -131,6 +131,9 @@ static inline struct iomap_page *to_iomap_page(struct page *page) >>>> return NULL; >>>> } >>>> >>>> +void __iomap_read_inline_data(struct inode *inode, struct page *page, >>>> + struct iomap *iomap); >>>> + >>>> ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, >>>> const struct iomap_ops *ops); >>>> int iomap_readpage(struct page *page, const struct iomap_ops *ops); >>>> >> . >> > . >