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* [Ocfs2-devel] [PATCH v4 0/8] gfs2: Fix mmap + page fault deadlocks
@ 2021-07-24 19:34 Andreas Gruenbacher
  2021-07-24 19:34 ` [Ocfs2-devel] [PATCH v4 1/8] iov_iter: Introduce iov_iter_fault_in_writeable helper Andreas Gruenbacher
                   ` (7 more replies)
  0 siblings, 8 replies; 19+ messages in thread
From: Andreas Gruenbacher @ 2021-07-24 19:34 UTC (permalink / raw)
  To: Linus Torvalds, Alexander Viro, Christoph Hellwig, Darrick J. Wong
  Cc: Jan Kara, Andreas Gruenbacher, linux-kernel, cluster-devel,
	linux-fsdevel, ocfs2-devel

Hi Linus et al.,

here's another update of this patch queue:

 * Finally fix the typos Linus has pointed out twice already.

 * Turn the previous fault_in_iov_iter helper that was used for reads
   and writes into iov_iter_fault_in_writeable per Al's suggestion.
   Use the existing iov_iter_fault_in_readable for writes.

 * Add a done_before argument and an IOMAP_DIO_FAULT_RETRY flag to
   iomap_dio_rw to allow iomap_dio_rw to return partial results and
   resume with the rest of a request.  This allows iomap_dio_rw to be
   used with page faults disabled without having to repeat any I/O.

 * Adjust the gfs2 patches accordingly.

With that, the two iov_ter patches and the three iomap patches should
hopefully be ready for mainline.

There's one remaining issue on the gfs2 side: during read requests, when
a writer now comes in in the middle of a read request, the read request
can currently return a result that never existed on disk.  So we need
to ensure that we only resume read requests when we know that no writer
got in the way, and retry the entire request otherwise.  It should be
relatively easy to add a mechanism to detect when a glock is "lost";
this won't affect the vfs or iomap patches.

Thanks a lot,
Andreas

Andreas Gruenbacher (8):
  iov_iter: Introduce iov_iter_fault_in_writeable helper
  gfs2: Add wrapper for iomap_file_buffered_write
  gfs2: Fix mmap + page fault deadlocks for buffered I/O
  iomap: Fix iomap_dio_rw return value for user copies
  iomap: Add done_before argument to iomap_dio_rw
  iomap: Support restarting direct I/O requests after user copy failures
  iov_iter: Introduce noio flag to disable page faults
  gfs2: Fix mmap + page fault deadlocks for direct I/O

 fs/btrfs/file.c       |  5 ++-
 fs/ext4/file.c        |  5 ++-
 fs/gfs2/file.c        | 95 +++++++++++++++++++++++++++++++++++++++----
 fs/iomap/direct-io.c  | 29 ++++++++++---
 fs/xfs/xfs_file.c     |  6 +--
 fs/zonefs/super.c     |  4 +-
 include/linux/iomap.h | 11 ++++-
 include/linux/mm.h    |  3 ++
 include/linux/uio.h   |  2 +
 lib/iov_iter.c        | 60 ++++++++++++++++++++++++---
 mm/gup.c              | 57 ++++++++++++++++++++++++++
 11 files changed, 246 insertions(+), 31 deletions(-)

-- 
2.26.3


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^ permalink raw reply	[flat|nested] 19+ messages in thread

end of thread, other threads:[~2021-07-27 17:52 UTC | newest]

Thread overview: 19+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-24 19:34 [Ocfs2-devel] [PATCH v4 0/8] gfs2: Fix mmap + page fault deadlocks Andreas Gruenbacher
2021-07-24 19:34 ` [Ocfs2-devel] [PATCH v4 1/8] iov_iter: Introduce iov_iter_fault_in_writeable helper Andreas Gruenbacher
2021-07-24 19:52   ` Linus Torvalds
2021-07-24 20:24     ` Al Viro
2021-07-24 20:37       ` Linus Torvalds
2021-07-24 21:38       ` Andreas Gruenbacher
2021-07-24 21:57         ` Al Viro
2021-07-24 22:06           ` Andreas Gruenbacher
2021-07-24 23:39             ` Al Viro
2021-07-27  9:30     ` David Laight
2021-07-27 11:13       ` Andreas Gruenbacher
2021-07-27 17:51         ` Linus Torvalds
2021-07-24 19:34 ` [Ocfs2-devel] [PATCH v4 2/8] gfs2: Add wrapper for iomap_file_buffered_write Andreas Gruenbacher
2021-07-24 19:34 ` [Ocfs2-devel] [PATCH v4 3/8] gfs2: Fix mmap + page fault deadlocks for buffered I/O Andreas Gruenbacher
2021-07-24 19:34 ` [Ocfs2-devel] [PATCH v4 4/8] iomap: Fix iomap_dio_rw return value for user copies Andreas Gruenbacher
2021-07-24 19:34 ` [Ocfs2-devel] [PATCH v4 5/8] iomap: Add done_before argument to iomap_dio_rw Andreas Gruenbacher
2021-07-24 19:34 ` [Ocfs2-devel] [PATCH v4 6/8] iomap: Support restarting direct I/O requests after user copy failures Andreas Gruenbacher
2021-07-24 19:34 ` [Ocfs2-devel] [PATCH v4 7/8] iov_iter: Introduce noio flag to disable page faults Andreas Gruenbacher
2021-07-24 19:34 ` [Ocfs2-devel] [PATCH v4 8/8] gfs2: Fix mmap + page fault deadlocks for direct I/O Andreas Gruenbacher

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