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| author | Pavel Begunkov <asml.silence@gmail.com> | 2021-06-09 12:07:25 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-06-14 08:23:05 -0600 |
| commit | 976517f162a05f4315b2373fd11585c395506259 (patch) | |
| tree | 5e51a188db23ab60450d530aca77cc0ee8b49008 /fs/io_uring.c | |
| parent | 40dad765c045ab6dbd481cc4f00d04953e77510c (diff) | |
| download | lwn-976517f162a05f4315b2373fd11585c395506259.tar.gz lwn-976517f162a05f4315b2373fd11585c395506259.zip | |
io_uring: fix blocking inline submission
There is a complaint against sys_io_uring_enter() blocking if it submits
stdin reads. The problem is in __io_file_supports_async(), which
sees that it's a cdev and allows it to be processed inline.
Punt char devices using generic rules of io_file_supports_async(),
including checking for presence of *_iter() versions of rw callbacks.
Apparently, it will affect most of cdevs with some exceptions like
null and zero devices.
Cc: stable@vger.kernel.org
Reported-by: Birk Hirdman <lonjil@gmail.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d60270856b8a4560a639ef5f76e55eb563633599.1623236455.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/io_uring.c')
| -rw-r--r-- | fs/io_uring.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index b93fa32172af..cdd9b53abbb2 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2618,7 +2618,7 @@ static bool __io_file_supports_async(struct file *file, int rw) return true; return false; } - if (S_ISCHR(mode) || S_ISSOCK(mode)) + if (S_ISSOCK(mode)) return true; if (S_ISREG(mode)) { if (IS_ENABLED(CONFIG_BLOCK) && |