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authorPavel Begunkov <asml.silence@gmail.com>2020-01-25 22:34:01 +0300
committerJens Axboe <axboe@kernel.dk>2020-01-27 15:36:30 -0700
commit9466f43741bc08edd7b1bee642dd6f5561091634 (patch)
tree514b35bd07f6e4dbaea3117cbdd859499594ec53 /fs/io_uring.c
parentio_uring: add comment for drain_next (diff)
downloadlinux-dev-9466f43741bc08edd7b1bee642dd6f5561091634.tar.xz
linux-dev-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>
Diffstat (limited to 'fs/io_uring.c')
-rw-r--r--fs/io_uring.c7
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)