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From: Goldwyn Rodrigues <rgoldwyn@suse.de>
To: linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org
Cc: darrick.wong@oracle.com, hch@infradead.org, nborisov@suse.com,
	Goldwyn Rodrigues <rgoldwyn@suse.com>
Subject: [PATCH v2 0/2] Fix locking for btrfs direct writes
Date: Tue, 15 Dec 2020 12:06:34 -0600	[thread overview]
Message-ID: <cover.1608053602.git.rgoldwyn@suse.com> (raw)

From: Goldwyn Rodrigues <rgoldwyn@suse.com>

BTRFS direct write takes the inode lock for performing the direct write.
In case of a failure or an incomplete write, it falls back to buffered
writes. Before initiating the buffered write, it releases the inode lock
and reacquires it for buffered write. This may lead to corruption if
another process attempts to write around the same offset between the
unlock and the relock. The patches change the flow so that the lock is
taken only once before the write and released only after the I/O is
complete.


Goldwyn Rodrigues (2):
  iomap: Separate out generic_write_sync() from iomap_dio_complete()
  btrfs: Make btrfs_direct_write atomic with respect to inode_lock

 fs/btrfs/file.c       | 69 +++++++++++++++++++++++++------------------
 fs/iomap/direct-io.c  | 16 ++++++++--
 include/linux/iomap.h |  2 +-
 3 files changed, 54 insertions(+), 33 deletions(-)

-- 
2.29.2


             reply	other threads:[~2020-12-15 18:07 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-15 18:06 Goldwyn Rodrigues [this message]
2020-12-15 18:06 ` [PATCH 1/2] iomap: Separate out generic_write_sync() from iomap_dio_complete() Goldwyn Rodrigues
2020-12-15 21:24   ` kernel test robot
2020-12-15 21:24     ` kernel test robot
2020-12-15 22:16   ` Dave Chinner
2020-12-15 18:06 ` [PATCH 2/2] btrfs: Make btrfs_direct_write atomic with respect to inode_lock Goldwyn Rodrigues
2020-12-15 22:13   ` Darrick J. Wong
2020-12-16 21:07     ` Goldwyn Rodrigues

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