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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 6051BC742AE for ; Fri, 12 Jul 2019 09:31:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4474E2084B for ; Fri, 12 Jul 2019 09:31:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726057AbfGLJbi (ORCPT ); Fri, 12 Jul 2019 05:31:38 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:2226 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725987AbfGLJbi (ORCPT ); Fri, 12 Jul 2019 05:31:38 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 40087FAAA7E9020E6BB6; Fri, 12 Jul 2019 17:31:35 +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; Fri, 12 Jul 2019 17:31:26 +0800 Subject: Re: [RFC PATCH] iomap: generalize IOMAP_INLINE to cover tail-packing case To: Andreas Gruenbacher CC: Christoph Hellwig , "Darrick J. Wong" , , , Gao Xiang , References: <20190703075502.79782-1-yuchao0@huawei.com> <39944e50-5888-f900-1954-91be2b12ea5b@huawei.com> <20190711122831.3970-1-agruenba@redhat.com> From: Chao Yu Message-ID: Date: Fri, 12 Jul 2019 17:31:24 +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: <20190711122831.3970-1-agruenba@redhat.com> Content-Type: text/plain; charset="windows-1252" 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 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? 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); >