From: Matthew Wilcox <willy@infradead.org>
To: David Howells <dhowells@redhat.com>
Cc: linux-fsdevel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Christoph Hellwig <hch@lst.de>,
linux-mm@kvack.org, linux-cachefs@redhat.com,
linux-afs@lists.infradead.org, linux-nfs@vger.kernel.org,
linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org,
v9fs-developer@lists.sourceforge.net,
Trond Myklebust <trond.myklebust@hammerspace.com>,
Anna Schumaker <anna.schumaker@netapp.com>,
Steve French <sfrench@samba.org>,
Dominique Martinet <asmadeus@codewreck.org>,
Jeff Layton <jlayton@redhat.com>,
David Wysochanski <dwysocha@redhat.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 02/30] mm: Add set/end/wait functions for PG_private_2
Date: Thu, 8 Apr 2021 15:50:57 +0100 [thread overview]
Message-ID: <20210408145057.GN2531743@casper.infradead.org> (raw)
In-Reply-To: <161789066013.6155.9816857201817288382.stgit@warthog.procyon.org.uk>
On Thu, Apr 08, 2021 at 03:04:20PM +0100, David Howells wrote:
> +static inline void set_page_private_2(struct page *page)
> +{
> + get_page(page);
> + SetPagePrivate2(page);
PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY)
So we can set Private2 on any tail page ...
> +void end_page_private_2(struct page *page)
> +{
> + page = compound_head(page);
> + VM_BUG_ON_PAGE(!PagePrivate2(page), page);
> + clear_bit_unlock(PG_private_2, &page->flags);
> + wake_up_page_bit(page, PG_private_2);
... but when we try to end on a tail, we actually wake up the head ...
> +void wait_on_page_private_2(struct page *page)
> +{
> + while (PagePrivate2(page))
> + wait_on_page_bit(page, PG_private_2);
... although if we were waiting on a tail, the wake up won't find us ...
if only we had a way to ensure this kind of bug can't happen *cough,
lend your support to the page folio patches*.
next prev parent reply other threads:[~2021-04-08 14:51 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-08 14:03 [PATCH v6 00/30] Network fs helper library & fscache kiocb API David Howells
2021-04-08 14:04 ` [PATCH v6 01/30] iov_iter: Add ITER_XARRAY David Howells
2021-04-09 1:24 ` Al Viro
2021-04-09 18:10 ` [RFC PATCH 1/2] iov_iter: Remove iov_iter_for_each_range() David Howells
2021-04-09 18:11 ` [RFC PATCH 2/2] iov_iter: Drop the X argument from iterate_all_kinds() and use B instead David Howells
2021-04-09 9:09 ` [PATCH v6 01/30] iov_iter: Add ITER_XARRAY David Howells
2021-04-09 11:44 ` Matthew Wilcox
2021-04-22 13:35 ` Jeff Layton
2021-04-22 13:51 ` David Howells
2021-04-22 14:51 ` Jeff Layton
2021-04-08 14:04 ` [PATCH v6 02/30] mm: Add set/end/wait functions for PG_private_2 David Howells
2021-04-08 14:50 ` Matthew Wilcox [this message]
2021-04-08 15:25 ` David Howells
2021-04-08 15:57 ` David Howells
2021-04-08 21:15 ` [RFC][PATCH] mm: Split page_has_private() in two to better handle PG_private_2 David Howells
2021-04-08 23:50 ` Linus Torvalds
2021-04-09 10:59 ` [RFC PATCH 1/3] Make the generic bitops return bool David Howells
2021-04-09 10:59 ` [RFC PATCH 2/3] mm: Return bool from pagebit test functions David Howells
2021-04-09 11:16 ` Matthew Wilcox
2021-04-09 12:00 ` David Howells
2021-04-09 12:35 ` David Howells
2021-04-09 16:03 ` David Howells
2021-04-09 10:59 ` [RFC PATCH 3/3] mm: Split page_has_private() in two to better handle PG_private_2 David Howells
2021-04-09 11:24 ` Matthew Wilcox
2021-04-09 8:14 ` [RFC][PATCH] " David Howells
2021-04-13 15:11 ` [PATCH v7] mm: Add set/end/wait functions for PG_private_2 David Howells
2021-04-13 15:22 ` Matthew Wilcox
2021-04-08 14:04 ` [PATCH v6 03/30] mm/filemap: Pass the file_ra_state in the ractl David Howells
2021-04-08 14:04 ` [PATCH v6 04/30] fs: Document file_ra_state David Howells
2021-04-08 14:04 ` [PATCH v6 05/30] mm: Implement readahead_control pageset expansion David Howells
2021-04-08 14:55 ` Matthew Wilcox
2021-04-08 14:05 ` [PATCH v6 06/30] netfs: Make a netfs helper module David Howells
2021-04-08 14:05 ` [PATCH v6 07/30] netfs: Documentation for helper library David Howells
2021-04-08 14:05 ` [PATCH v6 08/30] netfs, mm: Move PG_fscache helper funcs to linux/netfs.h David Howells
2021-04-08 14:05 ` [PATCH v6 09/30] netfs, mm: Add set/end/wait_on_page_fscache() aliases David Howells
2021-04-08 14:06 ` [PATCH v6 10/30] netfs: Provide readahead and readpage netfs helpers David Howells
2021-04-08 14:06 ` [PATCH v6 11/30] netfs: Add tracepoints David Howells
2021-04-08 14:06 ` [PATCH v6 12/30] netfs: Gather stats David Howells
2021-04-08 14:06 ` [PATCH v6 13/30] netfs: Add write_begin helper David Howells
2021-04-08 14:06 ` [PATCH v6 14/30] netfs: Define an interface to talk to a cache David Howells
2021-04-08 14:07 ` [PATCH v6 15/30] netfs: Add a tracepoint to log failures that would be otherwise unseen David Howells
2021-04-08 14:07 ` [PATCH v6 16/30] fscache, cachefiles: Add alternate API to use kiocb for read/write to cache David Howells
2021-04-08 14:07 ` [PATCH v6 17/30] afs: Disable use of the fscache I/O routines David Howells
2021-04-08 14:07 ` [PATCH v6 18/30] afs: Pass page into dirty region helpers to provide THP size David Howells
2021-04-08 14:08 ` [PATCH v6 19/30] afs: Print the operation debug_id when logging an unexpected data version David Howells
2021-04-08 14:08 ` [PATCH v6 20/30] afs: Move key to afs_read struct David Howells
2021-04-08 14:08 ` [PATCH v6 21/30] afs: Don't truncate iter during data fetch David Howells
2021-04-08 14:08 ` [PATCH v6 22/30] afs: Log remote unmarshalling errors David Howells
2021-04-08 14:08 ` [PATCH v6 23/30] afs: Set up the iov_iter before calling afs_extract_data() David Howells
2021-04-08 14:09 ` [PATCH v6 24/30] afs: Use ITER_XARRAY for writing David Howells
2021-04-08 14:09 ` [PATCH v6 25/30] afs: Wait on PG_fscache before modifying/releasing a page David Howells
2021-04-08 14:09 ` [PATCH v6 26/30] afs: Extract writeback extension into its own function David Howells
2021-04-08 14:09 ` [PATCH v6 27/30] afs: Prepare for use of THPs David Howells
2021-04-08 14:09 ` [PATCH v6 28/30] afs: Use the fs operation ops to handle FetchData completion David Howells
2021-04-08 14:10 ` [PATCH v6 29/30] afs: Use new netfs lib read helper API David Howells
2021-04-08 14:10 ` [PATCH v6 30/30] afs: Use the netfs_write_begin() helper David Howells
2021-04-08 15:40 ` [PATCH v6 00/30] Network fs helper library & fscache kiocb API Jeff Layton
2021-04-09 12:04 ` David Wysochanski
2021-04-13 14:56 ` David Wysochanski
2021-04-13 16:21 ` Marc Dionne
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=20210408145057.GN2531743@casper.infradead.org \
--to=willy@infradead.org \
--cc=anna.schumaker@netapp.com \
--cc=asmadeus@codewreck.org \
--cc=ceph-devel@vger.kernel.org \
--cc=dhowells@redhat.com \
--cc=dwysocha@redhat.com \
--cc=hch@lst.de \
--cc=jlayton@redhat.com \
--cc=linux-afs@lists.infradead.org \
--cc=linux-cachefs@redhat.com \
--cc=linux-cifs@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-nfs@vger.kernel.org \
--cc=sfrench@samba.org \
--cc=torvalds@linux-foundation.org \
--cc=trond.myklebust@hammerspace.com \
--cc=v9fs-developer@lists.sourceforge.net \
--cc=viro@zeniv.linux.org.uk \
/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).