https://github.com/torvalds/linux
Revision c8d317aa1887b40b188ec3aaa6e9e524333caed1 authored by Hao Xu on 29 September 2020, 12:00:45 UTC, committed by Jens Axboe on 29 September 2020, 13:54:00 UTC
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>
1 parent fad8e0d
Tip revision: c8d317aa1887b40b188ec3aaa6e9e524333caed1 authored by Hao Xu on 29 September 2020, 12:00:45 UTC
io_uring: fix async buffered reads when readahead is disabled
io_uring: fix async buffered reads when readahead is disabled
Tip revision: c8d317a
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| .clang-format | -rw-r--r-- | 15.8 KB |
| .cocciconfig | -rw-r--r-- | 59 bytes |
| .get_maintainer.ignore | -rw-r--r-- | 71 bytes |
| .gitattributes | -rw-r--r-- | 62 bytes |
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| COPYING | -rw-r--r-- | 496 bytes |
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| Kbuild | -rw-r--r-- | 1.3 KB |
| Kconfig | -rw-r--r-- | 555 bytes |
| MAINTAINERS | -rw-r--r-- | 555.8 KB |
| Makefile | -rw-r--r-- | 61.8 KB |
| README | -rw-r--r-- | 727 bytes |
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