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authorHao Xu <haoxu@linux.alibaba.com>2020-09-29 20:00:45 +0800
committerJens Axboe <axboe@kernel.dk>2020-09-29 07:54:00 -0600
commitc8d317aa1887b40b188ec3aaa6e9e524333caed1 (patch)
treeae6e8870004473d388c5f3275ad7888b6f74ec01 /fs
parentfad8e0de4426a776c9bcb060555e7c09e2d08db6 (diff)
downloadlinux-c8d317aa1887b40b188ec3aaa6e9e524333caed1.tar.bz2
io_uring: fix async buffered reads when readahead is disabled
The async buffered reads feature is not working when readahead is turned off. There are two things to concern: - when doing retry in io_read, not only the IOCB_WAITQ flag but also the IOCB_NOWAIT flag is still set, which makes it goes to would_block phase in generic_file_buffered_read() and then return -EAGAIN. After that, the io-wq thread work is queued, and later doing the async reads in the old way. - even if we remove IOCB_NOWAIT when doing retry, the feature is still not running properly, since in generic_file_buffered_read() it goes to lock_page_killable() after calling mapping->a_ops->readpage() to do IO, and thus causing process to sleep. Fixes: 1a0a7853b901 ("mm: support async buffered reads in generic_file_buffered_read()") Fixes: 3b2a4439e0ae ("io_uring: get rid of kiocb_wait_page_queue_init()") Signed-off-by: Hao Xu <haoxu@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs')
-rw-r--r--fs/io_uring.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 556e4a2ead07..b89cc87830b1 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3049,6 +3049,7 @@ static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode,
if (!wake_page_match(wpq, key))
return 0;
+ req->rw.kiocb.ki_flags &= ~IOCB_WAITQ;
list_del_init(&wait->entry);
init_task_work(&req->task_work, io_req_task_submit);
@@ -3106,6 +3107,7 @@ static bool io_rw_should_retry(struct io_kiocb *req)
wait->wait.flags = 0;
INIT_LIST_HEAD(&wait->wait.entry);
kiocb->ki_flags |= IOCB_WAITQ;
+ kiocb->ki_flags &= ~IOCB_NOWAIT;
kiocb->ki_waitq = wait;
io_get_req_task(req);