All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Theodore Ts'o" <tytso@mit.edu>
To: Jan Kara <jack@suse.cz>
Cc: linux-ext4@vger.kernel.org, Christoph Hellwig <hch@infradead.org>,
	"Ritesh Harjani (IBM)" <ritesh.list@gmail.com>,
	Christoph Hellwig <hch@lst.de>,
	Matthew Wilcox <willy@infradead.org>,
	linux-mm@kvack.org
Subject: Re: [PATCH v3 11/12] ext4: Stop providing .writepage hook
Date: Mon, 5 Dec 2022 22:17:26 -0500	[thread overview]
Message-ID: <Y460RpKTCDuPKWmN@mit.edu> (raw)
In-Reply-To: <20221205122928.21959-11-jack@suse.cz>

On Mon, Dec 05, 2022 at 01:29:25PM +0100, Jan Kara wrote:
> Now we don't need .writepage hook for anything anymore. Reclaim is fine
> with relying on .writepages to clean pages and we often couldn't do much
> from the .writepage callback anyway. We only need to provide
> .migrate_folio callback for the ext4_journalled_aops - let's use
> buffer_migrate_page_norefs() there so that buffers cannot be modified
  ^^^^^^^^^^^^^^^^^^^^^^^^^^  this should be buffer_migrate_folio_norefs, no?
> under jdb2's hands.
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Jan Kara <jack@suse.cz>

Could you clarify in the commit how critical it is to use the
_norefs() variant?  It's not entirely clear what you mean by "let's
use...".  I think what is meant is that we need to use ..._noref() or
we can get in trouble if while the page update is getting committed,
there is an attempted to migrate the folio containing the page.

buffer_migrate_folio_norefs() is currently not exported (although
buffer_migrate_folio is).  So if we need it for ext4, we're going to
have to EXPORT_SYMBOL buffer_migrate_folio_norefs.

Any objections from the mm folks?

				- Ted

  parent reply	other threads:[~2022-12-06  3:17 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-12-05 12:29 [PATCH v3 0/12] ext4: Stop using ext4_writepage() for writeout of ordered data Jan Kara
2022-12-05 12:29 ` [PATCH v3 01/12] ext4: Handle redirtying in ext4_bio_write_page() Jan Kara
2022-12-05 12:29 ` [PATCH v3 02/12] ext4: Move keep_towrite handling to ext4_bio_write_page() Jan Kara
2022-12-05 12:29 ` [PATCH v3 03/12] ext4: Remove nr_submitted from ext4_bio_write_page() Jan Kara
2022-12-05 12:29 ` [PATCH v3 04/12] ext4: Drop pointless IO submission " Jan Kara
2022-12-05 12:29 ` [PATCH v3 05/12] ext4: Add support for writepages calls that cannot map blocks Jan Kara
2022-12-05 12:29 ` [PATCH v3 06/12] ext4: Provide ext4_do_writepages() Jan Kara
2022-12-05 12:29 ` [PATCH v3 07/12] ext4: Move percpu_rwsem protection into ext4_writepages() Jan Kara
2022-12-05 12:29 ` [PATCH v3 08/12] ext4: Switch to using ext4_do_writepages() for ordered data writeout Jan Kara
2022-12-05 12:29 ` [PATCH v3 09/12] jbd2: Switch jbd2_submit_inode_data() to use fs-provided hook for " Jan Kara
2022-12-05 12:29 ` [PATCH v3 10/12] ext4: Switch to using write_cache_pages() for data=journal writeout Jan Kara
2022-12-05 12:29 ` [PATCH v3 11/12] ext4: Stop providing .writepage hook Jan Kara
2022-12-05 18:32   ` kernel test robot
2022-12-06  3:17   ` Theodore Ts'o [this message]
2022-12-06 10:52     ` Jan Kara
2022-12-07  7:38       ` Christoph Hellwig
2022-12-07 11:17         ` Jan Kara
2022-12-05 12:29 ` [PATCH v3 12/12] ext4: Remove ordered data support from ext4_writepage() Jan Kara

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=Y460RpKTCDuPKWmN@mit.edu \
    --to=tytso@mit.edu \
    --cc=hch@infradead.org \
    --cc=hch@lst.de \
    --cc=jack@suse.cz \
    --cc=linux-ext4@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=ritesh.list@gmail.com \
    --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: link
Be 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.