diff options
| author | Matthew Bobrowski <mbobrowski@mbobrowski.org> | 2019-11-05 22:59:22 +1100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-04 13:59:40 +0100 |
| commit | 47acc10500224436b3ea4c02b13550130ed4af33 (patch) | |
| tree | 34f0700034960702352a7795b4071c030c38d9d4 /fs | |
| parent | bcac8a188673a811eeb0dbbc5cce22340e4507ce (diff) | |
ext4: update direct I/O read lock pattern for IOCB_NOWAIT
[ Upstream commit 548feebec7e93e58b647dba70b3303dcb569c914 ]
This patch updates the lock pattern in ext4_direct_IO_read() to not
block on inode lock in cases of IOCB_NOWAIT direct I/O reads. The
locking condition implemented here is similar to that of 942491c9e6d6
("xfs: fix AIM7 regression").
Fixes: 16c54688592c ("ext4: Allow parallel DIO reads")
Signed-off-by: Matthew Bobrowski <mbobrowski@mbobrowski.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/c5d5e759f91747359fbd2c6f9a36240cf75ad79f.1572949325.git.mbobrowski@mbobrowski.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/inode.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index c2920cbfa3bf..a91b8404d3dc 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3796,7 +3796,13 @@ static ssize_t ext4_direct_IO_read(struct kiocb *iocb, struct iov_iter *iter) * writes & truncates and since we take care of writing back page cache, * we are protected against page writeback as well. */ - inode_lock_shared(inode); + if (iocb->ki_flags & IOCB_NOWAIT) { + if (!inode_trylock_shared(inode)) + return -EAGAIN; + } else { + inode_lock_shared(inode); + } + ret = filemap_write_and_wait_range(mapping, iocb->ki_pos, iocb->ki_pos + count - 1); if (ret) |