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From: Goldwyn Rodrigues <>
Subject: [PATCH 0/7 v8] btrfs direct-io using iomap
Date: Fri, 22 May 2020 07:38:30 -0500
Message-ID: <> (raw)

This is an effort to use iomap for direct I/O in btrfs. This would
change the call from __blockdev_direct_io() to iomap_dio_rw().

The main objective is to lose the buffer head and use bio defined by
iomap code, and hopefully to use more of generic-FS codebase.

These patches are based and tested on kdave/for-next-20200511. I
have tested it against xfstests/btrfs.

The tree is available at

Changes since v1
- Incorporated back the efficiency change for inode locking
- Review comments about coding style and git comments
- Merge related patches into one
- Direct read to go through btrfs_direct_IO()
- Removal of no longer used function dio_end_io()

Changes since v2
- aligning iomap offset/length to the position/length of I/O
- Removed btrfs_dio_data
- Re-incorporating write efficiency changes caused lockdep_assert() in
  iomap to be triggered, remove that code.

Changes since v3
- Fixed freeze on generic/095. Use iomap_end() to account for
  failed/incomplete dio instead of btrfs_dio_data

Changes since v4
- moved lockdep_assert_held() to functions calling iomap_dio_rw()
  This may be called immidiately after calling inode lock and
  may feel not required, but it seems important.
- Removed comments which are no longer required
- Changed commit comments to make them more appropriate

Changes since v5
- restore inode_dio_wait() in truncate
- Removed lockdep_assert_held() near callers

Changes since v6
- Fixed hangs due to underlying device failures
- Removed the patch to wait while releasing pages

Changes since v7
- Moved reservation into btrfs iomap begin()/end() for correct
  reservation cleanup in case of device error.
- Merged patches switch to iomap, and adding btrfs_iomap_end()
  for easier bisection. The switch to iomap would fail in case
  of dio after buffered writes.

             reply index

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-22 12:38 Goldwyn Rodrigues [this message]
2020-05-22 12:38 ` [PATCH 1/7] fs: Export generic_file_buffered_read() Goldwyn Rodrigues
2020-05-25 12:25   ` David Sterba
2020-05-22 12:38 ` [PATCH 2/7] iomap: add a filesystem hook for direct I/O bio submission Goldwyn Rodrigues
2020-05-22 12:38 ` [PATCH 3/7] iomap: Remove lockdep_assert_held() Goldwyn Rodrigues
2020-05-28 15:40   ` Darrick J. Wong
2020-05-28 16:45     ` Goldwyn Rodrigues
2020-05-22 12:38 ` [PATCH 4/7] btrfs: Switch to iomap_dio_rw() for dio Goldwyn Rodrigues
2020-05-26 15:03   ` Johannes Thumshirn
2020-05-26 16:44     ` Goldwyn Rodrigues
2020-05-28 15:13       ` Filipe Manana
2020-05-28 16:34         ` Goldwyn Rodrigues
2020-05-28 16:45           ` Filipe Manana
2020-05-28 18:38             ` Goldwyn Rodrigues
2020-06-03 11:35               ` Filipe Manana
2020-06-05 15:17                 ` Filipe Manana
2020-06-05 20:43                   ` Goldwyn Rodrigues
2020-05-22 12:38 ` [PATCH 5/7] fs: Remove dio_end_io() Goldwyn Rodrigues
2020-05-22 12:38 ` [PATCH 6/7] btrfs: remove BTRFS_INODE_READDIO_NEED_LOCK Goldwyn Rodrigues
2020-05-22 12:38 ` [PATCH 7/7] btrfs: btrfs: split btrfs_direct_IO Goldwyn Rodrigues

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