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| author | Pavel Begunkov <asml.silence@gmail.com> | 2020-01-25 22:34:01 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-01-27 15:36:30 -0700 |
| commit | 9466f43741bc08edd7b1bee642dd6f5561091634 (patch) | |
| tree | 514b35bd07f6e4dbaea3117cbdd859499594ec53 | |
| parent | 8cdf2193a3335b4cfb6e023b41ac293d0843d287 (diff) | |
| download | linux-9466f43741bc08edd7b1bee642dd6f5561091634.tar.gz linux-9466f43741bc08edd7b1bee642dd6f5561091634.tar.bz2 linux-9466f43741bc08edd7b1bee642dd6f5561091634.zip | |
io_uring: fix refcounting with batched allocations at OOM
In case of out of memory the second argument of percpu_ref_put_many() in
io_submit_sqes() may evaluate into "nr - (-EAGAIN)", that is clearly
wrong.
Fixes: 2b85edfc0c90 ("io_uring: batch getting pcpu references")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | fs/io_uring.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index a700ee5fc89d..1dd20305c664 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -4830,8 +4830,11 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr, break; } - if (submitted != nr) - percpu_ref_put_many(&ctx->refs, nr - submitted); + if (unlikely(submitted != nr)) { + int ref_used = (submitted == -EAGAIN) ? 0 : submitted; + + percpu_ref_put_many(&ctx->refs, nr - ref_used); + } if (link) io_queue_link_head(link); if (statep) |