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Subject[PATCH] io_uring: fix ctx refcounting in io_submit_sqes()
Date
If io_get_req() fails, it drops a ref. Then, awhile keeping @submitted
unmodified, io_submit_sqes() breaks the loop and puts @nr - @submitted
refs. For each submitted req a ref is dropped in io_put_req() and
friends. So, for @nr taken refs there will be
(@nr - @submitted + @submitted + 1) dropped.

Remove ctx refcounting from io_get_req(), that at the same time makes
it clearer.

Fixes: 2b85edfc0c90 ("io_uring: batch getting pcpu references")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
fs/io_uring.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 78ae8e8ed5bf..79bd22289d73 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1342,7 +1342,6 @@ static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx,
req = io_get_fallback_req(ctx);
if (req)
goto got_it;
- percpu_ref_put(&ctx->refs);
return NULL;
}

--
2.24.0
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