From: Pavel Begunkov Date: Tue, 4 Apr 2023 12:39:50 +0000 (+0100) Subject: io_uring/rsrc: kill rsrc_ref_lock X-Git-Tag: for-6.4/io_uring-2023-04-21~46 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=0a4813b1abdf06e44ce60cdebfd374cfd27c46bf;p=linux-block.git io_uring/rsrc: kill rsrc_ref_lock We use ->rsrc_ref_lock spinlock to protect ->rsrc_ref_list in io_rsrc_node_ref_zero(). Now we removed pcpu refcounting, which means io_rsrc_node_ref_zero() is not executed from the irq context as an RCU callback anymore, and we also put it under ->uring_lock. io_rsrc_node_switch(), which queues up nodes into the list, is also protected by ->uring_lock, so we can safely get rid of ->rsrc_ref_lock. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/6b60af883c263551190b526a55ff2c9d5ae07141.1680576071.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h index a0a5b5964d3a..9492889f00c0 100644 --- a/include/linux/io_uring_types.h +++ b/include/linux/io_uring_types.h @@ -333,8 +333,8 @@ struct io_ring_ctx { struct delayed_work rsrc_put_work; struct callback_head rsrc_put_tw; struct llist_head rsrc_put_llist; + /* protected by ->uring_lock */ struct list_head rsrc_ref_list; - spinlock_t rsrc_ref_lock; struct list_head io_buffers_pages; diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 36a76c7b34f0..764df5694d73 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -325,7 +325,6 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) INIT_LIST_HEAD(&ctx->defer_list); INIT_LIST_HEAD(&ctx->timeout_list); INIT_LIST_HEAD(&ctx->ltimeout_list); - spin_lock_init(&ctx->rsrc_ref_lock); INIT_LIST_HEAD(&ctx->rsrc_ref_list); INIT_DELAYED_WORK(&ctx->rsrc_put_work, io_rsrc_put_work); init_task_work(&ctx->rsrc_put_tw, io_rsrc_put_tw); diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c index 1237fc77c250..e122b6e5f9c5 100644 --- a/io_uring/rsrc.c +++ b/io_uring/rsrc.c @@ -209,11 +209,9 @@ void io_rsrc_node_ref_zero(struct io_rsrc_node *node) __must_hold(&node->rsrc_data->ctx->uring_lock) { struct io_ring_ctx *ctx = node->rsrc_data->ctx; - unsigned long flags; bool first_add = false; unsigned long delay = HZ; - spin_lock_irqsave(&ctx->rsrc_ref_lock, flags); node->done = true; /* if we are mid-quiesce then do not delay */ @@ -229,7 +227,6 @@ void io_rsrc_node_ref_zero(struct io_rsrc_node *node) list_del(&node->node); first_add |= llist_add(&node->llist, &ctx->rsrc_put_llist); } - spin_unlock_irqrestore(&ctx->rsrc_ref_lock, flags); if (!first_add) return; @@ -268,9 +265,7 @@ void io_rsrc_node_switch(struct io_ring_ctx *ctx, struct io_rsrc_node *rsrc_node = ctx->rsrc_node; rsrc_node->rsrc_data = data_to_kill; - spin_lock_irq(&ctx->rsrc_ref_lock); list_add_tail(&rsrc_node->node, &ctx->rsrc_ref_list); - spin_unlock_irq(&ctx->rsrc_ref_lock); atomic_inc(&data_to_kill->refs); /* put master ref */