Subject: [RFC PATCH 0/6] vfs: Make icache searchable under RCU
From:   David Howells <dhowells@redhat.com>
To:     viro@zeniv.linux.org.uk
Cc:     Jan Harkes <jaharkes@cs.cmu.edu>, Theodore Ts'o <tytso@mit.edu>,
        Andreas Dilger <adilger.kernel@dilger.ca>,
        codalist@coda.cs.cmu.edu, coda@cs.cmu.edu,
        linux-ext4@vger.kernel.org, linux-afs@lists.infradead.org,
        dhowells@redhat.com, linux-afs@lists.infradead.org,
        linux-ext4@vger.kernel.org, linux-ntfs-dev@lists.sourceforge.net,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Date:   Thu, 18 Apr 2019 15:05:51 +0100
Message-ID: <155559635133.21702.4737487773869377967.stgit@warthog.procyon.org.uk>
User-Agent: StGit/unknown-version
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
Sender: linux-ext4-owner@vger.kernel.org
Precedence: bulk


Hi Al

Here are some patches that make the icache searchable under RCU.  This
benefits ext4 (which can use it to find an inode to update the timestamps on)
and afs (which can use it to find a vnode to invalidate the callback promise
on).

It might also benefit NTFS, if its use ilookup5_nowait() can be substituted
for.  I'm not sure whether it actually needs to wait for inodes that are
undergoing deletion.

The first patch in the series attempts to fix the non-use of locking in Coda
when it moves an inode between buckets because it needs to update the search
key.

Thanks,
David
---
David Howells (6):
      vfs, coda: Fix the lack of locking in FID replacement inode rehashing
      vfs: Change inode_hash_lock to a seqlock
      vfs: Allow searching of the icache under RCU conditions
      afs: Use RCU inode cache search for callback resolution
      ext4: Search for an inode to update under the RCU lock if we can
      vfs: Delete find_inode_nowait()


 fs/afs/callback.c  |   12 ++
 fs/coda/cnode.c    |   11 ++
 fs/ext4/inode.c    |   41 ++++---
 fs/inode.c         |  309 ++++++++++++++++++++++++++++++++++++----------------
 include/linux/fs.h |   11 +-
 5 files changed, 260 insertions(+), 124 deletions(-)