From: Omar Sandoval <osandov@osandov.com>
To: linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org
Cc: kernel-team@fb.com
Subject: [PATCH 0/3] Btrfs: stop abusing current->journal_info for direct I/O
Date: Thu, 10 May 2018 23:30:09 -0700 [thread overview]
Message-ID: <cover.1525933432.git.osandov@fb.com> (raw)
From: Omar Sandoval <osandov@fb.com>
Hi, everyone,
Btrfs currently abuses current->journal_info in btrfs_direct_IO() in
order to pass around some state to get_block() and submit_io(). This
hack is ugly and unnecessary because the data we pass around is only
used in one call frame. Robbie Ko also pointed out [1] that it could
potentially cause a crash if we happen to end up in start_transaction()
(e.g., from memory reclaim calling into btrfs_evict_inode(), which can
start a transaction). I'm not convinced that Robbie's case can happen in
practice since we are using GFP_NOFS for allocations during direct I/O,
but either way it's fragile and nasty.
This series stops using current->journal_info and instead adds some
extra arguments to the generic direct I/O code so that we can pass
things around like sane people.
Based on Linus' master.
Thanks!
1: https://patchwork.kernel.org/patch/10389077/
Omar Sandoval (3):
fs: add initial bh_result->b_private value to __blockdev_direct_IO()
fs: add private argument to dio_submit_t
Btrfs: stop abusing current->journal_info in btrfs_direct_IO()
fs/btrfs/inode.c | 39 ++++++++++-----------------------------
fs/direct-io.c | 12 +++++++-----
fs/ext4/inode.c | 6 +++---
fs/gfs2/aops.c | 2 +-
fs/ocfs2/aops.c | 5 ++---
include/linux/fs.h | 10 +++++-----
6 files changed, 28 insertions(+), 46 deletions(-)
--
2.17.0
next reply other threads:[~2018-05-11 6:30 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-11 6:30 Omar Sandoval [this message]
2018-05-11 6:30 ` [PATCH 1/3] fs: add initial bh_result->b_private value to __blockdev_direct_IO() Omar Sandoval
2018-05-11 20:05 ` Al Viro
2018-05-11 20:30 ` Omar Sandoval
2018-05-11 20:32 ` Al Viro
2018-05-11 20:41 ` Omar Sandoval
2018-05-14 16:35 ` David Sterba
2018-06-25 17:16 ` David Sterba
2018-06-29 7:02 ` Omar Sandoval
2018-05-11 6:30 ` [PATCH 2/3] fs: add private argument to dio_submit_t Omar Sandoval
2018-05-11 6:30 ` [PATCH 3/3] Btrfs: stop abusing current->journal_info in btrfs_direct_IO() Omar Sandoval
2018-05-11 9:26 ` [PATCH 0/3] Btrfs: stop abusing current->journal_info for direct I/O David Sterba
2018-05-11 9:53 ` Nikolay Borisov
2018-05-11 10:24 ` David Sterba
2018-05-11 17:28 ` Omar Sandoval
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