From: Gao Xiang <hsiangkao@linux.alibaba.com> To: Matthew Wilcox <willy@infradead.org> Cc: "Andreas Grünbacher" <andreas.gruenbacher@gmail.com>, "Christoph Hellwig" <hch@infradead.org>, linux-erofs@lists.ozlabs.org, "Linux FS-devel Mailing List" <linux-fsdevel@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>, "Darrick J. Wong" <djwong@kernel.org>, "Chao Yu" <chao@kernel.org>, "Liu Bo" <bo.liu@linux.alibaba.com>, "Joseph Qi" <joseph.qi@linux.alibaba.com>, "Liu Jiang" <gerry@linux.alibaba.com> Subject: Re: [PATCH 1/2] iomap: support tail packing inline read Date: Sat, 17 Jul 2021 23:15:58 +0800 [thread overview] Message-ID: <YPL0LqHzEbUY4zY/@B-P7TQMD6M-0146.local> (raw) In-Reply-To: <YPLw0uc1jVKI8uKo@casper.infradead.org> Hi Matthew, On Sat, Jul 17, 2021 at 04:01:38PM +0100, Matthew Wilcox wrote: > On Sat, Jul 17, 2021 at 09:38:18PM +0800, Gao Xiang wrote: > > Sorry about some late. I've revised a version based on Christoph's > > version and Matthew's thought above. I've preliminary checked with > > EROFS, if it does make sense, please kindly help check on the gfs2 > > side as well.. > > I don't understand how this bit works: This part inherited from the Christoph version without change. The following thoughts are just my own understanding... > > > struct page *page = ctx->cur_page; > > - struct iomap_page *iop; > > + struct iomap_page *iop = NULL; > > bool same_page = false, is_contig = false; > > loff_t orig_pos = pos; > > unsigned poff, plen; > > sector_t sector; > > > > - if (iomap->type == IOMAP_INLINE) { > > - WARN_ON_ONCE(pos); > > - iomap_read_inline_data(inode, page, iomap); > > - return PAGE_SIZE; > > - } > > + if (iomap->type == IOMAP_INLINE && !pos) > > + WARN_ON_ONCE(to_iomap_page(page) != NULL); > > + else > > + iop = iomap_page_create(inode, page); > > Imagine you have a file with bytes 0-2047 in an extent which is !INLINE > and bytes 2048-2051 in the INLINE extent. When you read the page, first > you create an iop for the !INLINE extent. Then this function is called Yes, it first created an iop for the !INLINE extent. > again for the INLINE extent and you'll hit the WARN_ON_ONCE. No? If it is called again with another INLINE extent, pos will be non-0? so (!pos) == false. Am I missing something? Thanks, Gao Xiang >
WARNING: multiple messages have this Message-ID (diff)
From: Gao Xiang <hsiangkao@linux.alibaba.com> To: Matthew Wilcox <willy@infradead.org> Cc: "Darrick J. Wong" <djwong@kernel.org>, "Andreas Grünbacher" <andreas.gruenbacher@gmail.com>, LKML <linux-kernel@vger.kernel.org>, "Christoph Hellwig" <hch@infradead.org>, "Joseph Qi" <joseph.qi@linux.alibaba.com>, "Liu Bo" <bo.liu@linux.alibaba.com>, "Linux FS-devel Mailing List" <linux-fsdevel@vger.kernel.org>, "Liu Jiang" <gerry@linux.alibaba.com>, linux-erofs@lists.ozlabs.org Subject: Re: [PATCH 1/2] iomap: support tail packing inline read Date: Sat, 17 Jul 2021 23:15:58 +0800 [thread overview] Message-ID: <YPL0LqHzEbUY4zY/@B-P7TQMD6M-0146.local> (raw) In-Reply-To: <YPLw0uc1jVKI8uKo@casper.infradead.org> Hi Matthew, On Sat, Jul 17, 2021 at 04:01:38PM +0100, Matthew Wilcox wrote: > On Sat, Jul 17, 2021 at 09:38:18PM +0800, Gao Xiang wrote: > > Sorry about some late. I've revised a version based on Christoph's > > version and Matthew's thought above. I've preliminary checked with > > EROFS, if it does make sense, please kindly help check on the gfs2 > > side as well.. > > I don't understand how this bit works: This part inherited from the Christoph version without change. The following thoughts are just my own understanding... > > > struct page *page = ctx->cur_page; > > - struct iomap_page *iop; > > + struct iomap_page *iop = NULL; > > bool same_page = false, is_contig = false; > > loff_t orig_pos = pos; > > unsigned poff, plen; > > sector_t sector; > > > > - if (iomap->type == IOMAP_INLINE) { > > - WARN_ON_ONCE(pos); > > - iomap_read_inline_data(inode, page, iomap); > > - return PAGE_SIZE; > > - } > > + if (iomap->type == IOMAP_INLINE && !pos) > > + WARN_ON_ONCE(to_iomap_page(page) != NULL); > > + else > > + iop = iomap_page_create(inode, page); > > Imagine you have a file with bytes 0-2047 in an extent which is !INLINE > and bytes 2048-2051 in the INLINE extent. When you read the page, first > you create an iop for the !INLINE extent. Then this function is called Yes, it first created an iop for the !INLINE extent. > again for the INLINE extent and you'll hit the WARN_ON_ONCE. No? If it is called again with another INLINE extent, pos will be non-0? so (!pos) == false. Am I missing something? Thanks, Gao Xiang >
next prev parent reply other threads:[~2021-07-17 15:16 UTC|newest] Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-16 5:07 [PATCH 0/2] erofs: iomap support for tailpacking cases Gao Xiang 2021-07-16 5:07 ` Gao Xiang 2021-07-16 5:07 ` [PATCH 1/2] iomap: support tail packing inline read Gao Xiang 2021-07-16 5:07 ` Gao Xiang 2021-07-16 9:19 ` Christoph Hellwig 2021-07-16 9:19 ` Christoph Hellwig 2021-07-16 9:46 ` Gao Xiang 2021-07-16 9:46 ` Gao Xiang 2021-07-16 13:47 ` Matthew Wilcox 2021-07-16 13:47 ` Matthew Wilcox 2021-07-16 14:38 ` Matthew Wilcox 2021-07-16 14:38 ` Matthew Wilcox 2021-07-16 13:02 ` Matthew Wilcox 2021-07-16 13:02 ` Matthew Wilcox 2021-07-16 13:56 ` Gao Xiang 2021-07-16 13:56 ` Gao Xiang 2021-07-16 14:44 ` Matthew Wilcox 2021-07-16 15:03 ` Gao Xiang 2021-07-16 15:03 ` Gao Xiang 2021-07-16 15:53 ` Andreas Grünbacher 2021-07-16 15:53 ` Andreas Grünbacher 2021-07-17 13:38 ` Gao Xiang 2021-07-17 13:38 ` Gao Xiang 2021-07-17 15:01 ` Matthew Wilcox 2021-07-17 15:15 ` Gao Xiang [this message] 2021-07-17 15:15 ` Gao Xiang 2021-07-17 18:40 ` Matthew Wilcox 2021-07-19 11:19 ` Christoph Hellwig 2021-07-19 11:19 ` Christoph Hellwig 2021-07-19 13:45 ` Gao Xiang 2021-07-19 13:45 ` Gao Xiang 2021-07-19 11:15 ` Christoph Hellwig 2021-07-19 13:31 ` Gao Xiang 2021-07-19 13:31 ` Gao Xiang 2021-07-16 5:07 ` [PATCH 2/2] erofs: convert all uncompressed cases to iomap Gao Xiang 2021-07-16 5:07 ` Gao Xiang 2021-07-18 5:30 ` kernel test robot 2021-07-18 5:30 ` [RFC PATCH] erofs: erofs_iomap_end() can be static kernel test robot 2021-07-18 16:53 ` Gao Xiang
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=YPL0LqHzEbUY4zY/@B-P7TQMD6M-0146.local \ --to=hsiangkao@linux.alibaba.com \ --cc=andreas.gruenbacher@gmail.com \ --cc=bo.liu@linux.alibaba.com \ --cc=chao@kernel.org \ --cc=djwong@kernel.org \ --cc=gerry@linux.alibaba.com \ --cc=hch@infradead.org \ --cc=joseph.qi@linux.alibaba.com \ --cc=linux-erofs@lists.ozlabs.org \ --cc=linux-fsdevel@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=willy@infradead.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.