From: Matthew Wilcox <willy@infradead.org>
To: Qian Cai <cai@redhat.com>
Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
"Darrick J . Wong" <darrick.wong@oracle.com>,
Christoph Hellwig <hch@infradead.org>,
linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org,
Dave Kleikamp <shaggy@kernel.org>,
jfs-discussion@lists.sourceforge.net,
Dave Chinner <dchinner@redhat.com>,
Stephen Rothwell <sfr@canb.auug.org.au>,
linux-next@vger.kernel.org
Subject: Re: [PATCH v2 5/9] iomap: Support arbitrarily many blocks per page
Date: Tue, 22 Sep 2020 18:05:26 +0100 [thread overview]
Message-ID: <20200922170526.GK32101@casper.infradead.org> (raw)
In-Reply-To: <163f852ba12fd9de5dec7c4a2d6b6c7cdb379ebc.camel@redhat.com>
On Tue, Sep 22, 2020 at 12:23:45PM -0400, Qian Cai wrote:
> On Fri, 2020-09-11 at 00:47 +0100, Matthew Wilcox (Oracle) wrote:
> > Size the uptodate array dynamically to support larger pages in the
> > page cache. With a 64kB page, we're only saving 8 bytes per page today,
> > but with a 2MB maximum page size, we'd have to allocate more than 4kB
> > per page. Add a few debugging assertions.
> >
> > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> > Reviewed-by: Dave Chinner <dchinner@redhat.com>
>
> Some syscall fuzzing will trigger this on powerpc:
>
> .config: https://gitlab.com/cailca/linux-mm/-/blob/master/powerpc.config
>
> [ 8805.895344][T445431] WARNING: CPU: 61 PID: 445431 at fs/iomap/buffered-io.c:78 iomap_page_release+0x250/0x270
Well, I'm glad it triggered. That warning is:
WARN_ON_ONCE(bitmap_full(iop->uptodate, nr_blocks) !=
PageUptodate(page));
so there was definitely a problem of some kind.
truncate_cleanup_page() calls
do_invalidatepage() calls
iomap_invalidatepage() calls
iomap_page_release()
Is this the first warning? I'm wondering if maybe there was an I/O error
earlier which caused PageUptodate to get cleared again. If it's easy to
reproduce, perhaps you could try something like this?
+void dump_iomap_page(struct page *page, const char *reason)
+{
+ struct iomap_page *iop = to_iomap_page(page);
+ unsigned int nr_blocks = i_blocks_per_page(page->mapping->host, page);
+
+ dump_page(page, reason);
+ if (iop)
+ printk("iop:reads %d writes %d uptodate %*pb\n",
+ atomic_read(&iop->read_bytes_pending),
+ atomic_read(&iop->write_bytes_pending),
+ nr_blocks, iop->uptodate);
+ else
+ printk("iop:none\n");
+}
and then do something like:
if (bitmap_full(iop->uptodate, nr_blocks) != PageUptodate(page))
dump_iomap_page(page, NULL);
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
next prev parent reply other threads:[~2020-09-22 17:05 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-10 23:46 [PATCH v2 0/9] THP iomap patches for 5.10 Matthew Wilcox (Oracle)
2020-09-10 23:46 ` [PATCH v2 1/9] iomap: Fix misplaced page flushing Matthew Wilcox (Oracle)
2020-09-10 23:47 ` [PATCH v2 2/9] fs: Introduce i_blocks_per_page Matthew Wilcox (Oracle)
2020-09-15 14:58 ` Dave Kleikamp
2020-09-15 15:40 ` David Laight
2020-09-15 15:49 ` Matthew Wilcox
2020-09-10 23:47 ` [PATCH v2 3/9] iomap: Use kzalloc to allocate iomap_page Matthew Wilcox (Oracle)
2020-09-10 23:47 ` [PATCH v2 4/9] iomap: Use bitmap ops to set uptodate bits Matthew Wilcox (Oracle)
2020-09-10 23:47 ` [PATCH v2 5/9] iomap: Support arbitrarily many blocks per page Matthew Wilcox (Oracle)
2020-09-11 5:36 ` Christoph Hellwig
2020-09-17 22:00 ` Darrick J. Wong
2020-09-22 16:23 ` Qian Cai
2020-09-22 17:05 ` Matthew Wilcox [this message]
2020-09-22 17:25 ` Qian Cai
2020-09-23 1:06 ` Qian Cai
2020-09-23 2:48 ` Matthew Wilcox
2020-09-23 5:00 ` Darrick J. Wong
2020-09-23 18:59 ` Matthew Wilcox
2020-09-23 16:55 ` Qian Cai
2020-09-24 1:07 ` Matthew Wilcox
2020-09-10 23:47 ` [PATCH v2 6/9] iomap: Convert read_count to read_bytes_pending Matthew Wilcox (Oracle)
2020-09-11 5:36 ` Christoph Hellwig
2020-09-17 22:02 ` Darrick J. Wong
2020-09-10 23:47 ` [PATCH v2 7/9] iomap: Convert write_count to write_bytes_pending Matthew Wilcox (Oracle)
2020-09-17 22:02 ` Darrick J. Wong
2020-09-10 23:47 ` [PATCH v2 8/9] iomap: Convert iomap_write_end types Matthew Wilcox (Oracle)
2020-09-17 22:03 ` Darrick J. Wong
2020-09-10 23:47 ` [PATCH v2 9/9] iomap: Change calling convention for zeroing Matthew Wilcox (Oracle)
2020-09-11 6:42 ` Christoph Hellwig
2020-09-17 22:05 ` Darrick J. Wong
2020-09-17 22:11 ` Matthew Wilcox
2020-09-17 22:18 ` Darrick J. Wong
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=20200922170526.GK32101@casper.infradead.org \
--to=willy@infradead.org \
--cc=cai@redhat.com \
--cc=darrick.wong@oracle.com \
--cc=dchinner@redhat.com \
--cc=hch@infradead.org \
--cc=jfs-discussion@lists.sourceforge.net \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-next@vger.kernel.org \
--cc=linux-nvdimm@lists.01.org \
--cc=linux-xfs@vger.kernel.org \
--cc=sfr@canb.auug.org.au \
--cc=shaggy@kernel.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: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).