aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorMatthew Bobrowski <[email protected]>2019-11-05 22:59:22 +1100
committerTheodore Ts'o <[email protected]>2019-11-05 11:31:39 -0500
commit548feebec7e93e58b647dba70b3303dcb569c914 (patch)
tree4f345cdb41a3835dd3c8047ee480a4c942912ddf
parent53e5cca56795a301bbe8465781dab084f7ae8d54 (diff)
ext4: update direct I/O read lock pattern for IOCB_NOWAIT
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 <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ritesh Harjani <[email protected]> Link: https://lore.kernel.org/r/c5d5e759f91747359fbd2c6f9a36240cf75ad79f.1572949325.git.mbobrowski@mbobrowski.org Signed-off-by: Theodore Ts'o <[email protected]>
-rw-r--r--fs/ext4/inode.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index e4b0722717b3..f33fa86fff67 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3881,7 +3881,13 @@ 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)