diff mbox series

io_uring: Don't require reinitable percpu_ref

Message ID 20220715174501.25216-1-mkoutny@suse.com (mailing list archive)
State New
Headers show
Series io_uring: Don't require reinitable percpu_ref | expand

Commit Message

Michal Koutný July 15, 2022, 5:45 p.m. UTC 
The commit 8bb649ee1da3 ("io_uring: remove ring quiesce for
io_uring_register") removed the worklow relying on reinit/resurrection
of the percpu_ref, hence, initialization with that requested is a relic.

This is based on code review, this causes no real bug (and theoretically
can't). Technically it's a revert of commit 214828962dea ("io_uring:
initialize percpu refcounters using PERCU_REF_ALLOW_REINIT") but since
the flag omission is now justified, I'm not making this a revert.

Fixes: 8bb649ee1da3 ("io_uring: remove ring quiesce for io_uring_register")
Signed-off-by: Michal Koutný <mkoutny@suse.com>
---
 fs/io_uring.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Roman Gushchin July 15, 2022, 5:54 p.m. UTC | #1 
On Fri, Jul 15, 2022 at 07:45:01PM +0200, Michal Koutny wrote:
> The commit 8bb649ee1da3 ("io_uring: remove ring quiesce for
> io_uring_register") removed the worklow relying on reinit/resurrection
> of the percpu_ref, hence, initialization with that requested is a relic.
> 
> This is based on code review, this causes no real bug (and theoretically
> can't). Technically it's a revert of commit 214828962dea ("io_uring:
> initialize percpu refcounters using PERCU_REF_ALLOW_REINIT") but since
> the flag omission is now justified, I'm not making this a revert.
> 
> Fixes: 8bb649ee1da3 ("io_uring: remove ring quiesce for io_uring_register")
> Signed-off-by: Michal Koutný <mkoutny@suse.com>

Acked-by: Roman Gushchin <roman.gushchin@linux.dev>

Thanks!
Jens Axboe July 15, 2022, 6:22 p.m. UTC | #2 
On 7/15/22 11:45 AM, Michal Koutn? wrote:
> The commit 8bb649ee1da3 ("io_uring: remove ring quiesce for
> io_uring_register") removed the worklow relying on reinit/resurrection
> of the percpu_ref, hence, initialization with that requested is a relic.
> 
> This is based on code review, this causes no real bug (and theoretically
> can't). Technically it's a revert of commit 214828962dea ("io_uring:
> initialize percpu refcounters using PERCU_REF_ALLOW_REINIT") but since
> the flag omission is now justified, I'm not making this a revert.

Thanks, applied manually for 5.20 (new file location).
diff mbox series

Patch

diff --git a/fs/io_uring.c b/fs/io_uring.c
index a01ea49f3017..563f2266c674 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1911,7 +1911,7 @@  static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
 	ctx->dummy_ubuf->ubuf = -1UL;
 
 	if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free,
-			    PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))
+			    0, GFP_KERNEL))
 		goto err;
 
 	ctx->flags = p->flags;