[PATCH v6 00/11] ext4: port direct I/O to iomap infrastructure

From: Matthew Bobrowski <mbobrowski@mbobrowski.org>
To: tytso@mit.edu, jack@suse.cz, adilger.kernel@dilger.ca
Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	hch@infradead.org, david@fromorbit.com, darrick.wong@oracle.com
Subject: [PATCH v6 00/11] ext4: port direct I/O to iomap infrastructure
Date: Mon, 28 Oct 2019 21:50:03 +1100	[thread overview]
Message-ID: <cover.1572255424.git.mbobrowski@mbobrowski.org> (raw)

Hi!

OK, so I think we're now coming very close to having this patch series
ready, if not already there. I've made some slight amendments to this
patch series as a result of the last round of feedback. This patch
series is based off Darrick's iomap-for-next branch, as there are some
iomap API changes there that we're dependent on here.

Changes since v5:

 - Fixed up calling into __generic_file_fsync() from
   ext4_sync_file(). Previously this caused a recursive lock situation
   when the filesystem was created without a journal.

 - Rolled up the orphan handling code from ext4_dio_write_iter() into
   ext4_handle_inode_extension().

 - Dropped redundant conditional statement and expression from
   ext4_iomap_is_delalloc().

 - Fixed up a couple comments, changelogs, as well as some other
   really minor grammatical corrections.

This patch series ports the ext4 direct I/O paths over to the iomap
infrastructure. The legacy buffer_head based direct I/O implementation
has subsequently been removed as it's no longer in use. The result of
this change is that ext4 now uses the newer iomap framework for direct
I/O read/write operations. Overall, this results in a much cleaner
direct I/O implementation and keeps this code isolated from the
buffer_head internals. In addition to this, a slight performance boost
may be expected while using O_SYNC | O_DIRECT.

The changes within this patch series have been tested via xfstests in
both DAX and non-DAX modes using the various filesystem configuration
options, including: 4k, dioread_nolock, nojournal.

Matthew Bobrowski (11):
  ext4: reorder map.m_flags checks within ext4_iomap_begin()
  ext4: update direct I/O read lock pattern for IOCB_NOWAIT
  ext4: iomap that extends beyond EOF should be marked dirty
  ext4: move set iomap routines into a separate helper ext4_set_iomap()
  ext4: split IOMAP_WRITE branch in ext4_iomap_begin() into helper
  ext4: introduce new callback for IOMAP_REPORT
  ext4: introduce direct I/O read using iomap infrastructure
  ext4: move inode extension/truncate code out from ->iomap_end()
    callback
  ext4: move inode extension check out from ext4_iomap_alloc()
  ext4: update ext4_sync_file() to not use __generic_file_fsync()
  ext4: introduce direct I/O write using iomap infrastructure

 fs/ext4/ext4.h    |   4 +-
 fs/ext4/extents.c |  11 +-
 fs/ext4/file.c    | 387 ++++++++++++++++++++-----
 fs/ext4/fsync.c   |  72 +++--
 fs/ext4/inode.c   | 714 +++++++++++-----------------------------------
 5 files changed, 537 insertions(+), 651 deletions(-)

-- 
2.20.1