[GIT PULL] Fix gfs2 readahead deadlocks

From: Andreas Gruenbacher <agruenba@redhat.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>,
	Dave Chinner <david@fromorbit.com>, Jens Axboe <axboe@kernel.dk>,
	cluster-devel@redhat.com, linux-fsdevel@vger.kernel.org,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Andreas Gruenbacher <agruenba@redhat.com>
Subject: [GIT PULL] Fix gfs2 readahead deadlocks
Date: Fri, 10 Jul 2020 17:23:24 +0200	[thread overview]
Message-ID: <20200710152324.1690683-1-agruenba@redhat.com> (raw)

Hi Linus,

could you please pull the following two commits to fix the gfs2
deadlocks resulting from the conversion to ->readahead in commit
d4388340ae0b ("fs: convert mpage_readpages to mpage_readahead")?

The first commit adds a new IOCB_NOIO flag to generic_file_read_iter.

In the previous version [1] which you've acked [2] and Matthew Willcox
has reviewed [3], ->readpage could still be called even when IOCB_NOIO
was set, so I've added an additional check above that call and I've
dropped the ack and reviewed-by tags.  In addition, bit 8 is now left
unused for the new IOCB_WAITQ flag in the block tree per Jens Axboe's
request.

[1] https://lore.kernel.org/linux-fsdevel/CAHc6FU6LmR7m_8UHmB_77jUpYNo-kgCZ-1YTLqya-PPqvvBy7Q@mail.gmail.com/
[2] https://lore.kernel.org/linux-fsdevel/CAHk-=whBk-jYM6_HBXbu6+gs7Gtw3hWg4iSLncQ0QTwShm6Jaw@mail.gmail.com/
[3] https://lore.kernel.org/linux-fsdevel/20200703114108.GE25523@casper.infradead.org/

Thanks a lot,
Andreas

The following changes since commit dcb7fd82c75ee2d6e6f9d8cc71c52519ed52e258:

  Linux 5.8-rc4 (2020-07-05 16:20:22 -0700)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2.git tags/gfs2-v5.8-rc4.fixes

for you to fetch changes up to 20f829999c38b18e3d17f9e40dea3a28f721fac4:

  gfs2: Rework read and page fault locking (2020-07-07 23:40:12 +0200)

----------------------------------------------------------------
Fix gfs2 readahead deadlocks

----------------------------------------------------------------
Andreas Gruenbacher (2):
      fs: Add IOCB_NOIO flag for generic_file_read_iter
      gfs2: Rework read and page fault locking

 fs/gfs2/aops.c     | 45 +--------------------------------------------
 fs/gfs2/file.c     | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 include/linux/fs.h |  1 +
 mm/filemap.c       | 23 +++++++++++++++++++++--
 4 files changed, 73 insertions(+), 48 deletions(-)