133 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			133 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #include <linux/kernel.h>
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| #include <linux/errno.h>
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| #include <linux/file.h>
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| #include <linux/slab.h>
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| #include <linux/net.h>
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| #include <linux/io_uring.h>
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| 
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| #include "io_uring.h"
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| #include "notif.h"
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| #include "rsrc.h"
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| 
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| static const struct ubuf_info_ops io_ubuf_ops;
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| 
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| static void io_notif_tw_complete(struct io_kiocb *notif, struct io_tw_state *ts)
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| {
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| 	struct io_notif_data *nd = io_notif_to_data(notif);
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| 
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| 	do {
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| 		notif = cmd_to_io_kiocb(nd);
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| 
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| 		lockdep_assert(refcount_read(&nd->uarg.refcnt) == 0);
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| 
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| 		if (unlikely(nd->zc_report) && (nd->zc_copied || !nd->zc_used))
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| 			notif->cqe.res |= IORING_NOTIF_USAGE_ZC_COPIED;
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| 
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| 		if (nd->account_pages && notif->ctx->user) {
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| 			__io_unaccount_mem(notif->ctx->user, nd->account_pages);
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| 			nd->account_pages = 0;
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| 		}
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| 
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| 		nd = nd->next;
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| 		io_req_task_complete(notif, ts);
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| 	} while (nd);
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| }
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| 
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| void io_tx_ubuf_complete(struct sk_buff *skb, struct ubuf_info *uarg,
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| 			 bool success)
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| {
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| 	struct io_notif_data *nd = container_of(uarg, struct io_notif_data, uarg);
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| 	struct io_kiocb *notif = cmd_to_io_kiocb(nd);
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| 	unsigned tw_flags;
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| 
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| 	if (nd->zc_report) {
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| 		if (success && !nd->zc_used && skb)
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| 			WRITE_ONCE(nd->zc_used, true);
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| 		else if (!success && !nd->zc_copied)
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| 			WRITE_ONCE(nd->zc_copied, true);
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| 	}
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| 
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| 	if (!refcount_dec_and_test(&uarg->refcnt))
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| 		return;
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| 
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| 	if (nd->head != nd) {
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| 		io_tx_ubuf_complete(skb, &nd->head->uarg, success);
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| 		return;
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| 	}
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| 
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| 	tw_flags = nd->next ? 0 : IOU_F_TWQ_LAZY_WAKE;
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| 	notif->io_task_work.func = io_notif_tw_complete;
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| 	__io_req_task_work_add(notif, tw_flags);
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| }
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| 
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| static int io_link_skb(struct sk_buff *skb, struct ubuf_info *uarg)
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| {
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| 	struct io_notif_data *nd, *prev_nd;
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| 	struct io_kiocb *prev_notif, *notif;
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| 	struct ubuf_info *prev_uarg = skb_zcopy(skb);
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| 
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| 	nd = container_of(uarg, struct io_notif_data, uarg);
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| 	notif = cmd_to_io_kiocb(nd);
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| 
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| 	if (!prev_uarg) {
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| 		net_zcopy_get(&nd->uarg);
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| 		skb_zcopy_init(skb, &nd->uarg);
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| 		return 0;
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| 	}
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| 	/* handle it separately as we can't link a notif to itself */
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| 	if (unlikely(prev_uarg == &nd->uarg))
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| 		return 0;
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| 	/* we can't join two links together, just request a fresh skb */
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| 	if (unlikely(nd->head != nd || nd->next))
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| 		return -EEXIST;
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| 	/* don't mix zc providers */
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| 	if (unlikely(prev_uarg->ops != &io_ubuf_ops))
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| 		return -EEXIST;
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| 
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| 	prev_nd = container_of(prev_uarg, struct io_notif_data, uarg);
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| 	prev_notif = cmd_to_io_kiocb(nd);
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| 
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| 	/* make sure all noifications can be finished in the same task_work */
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| 	if (unlikely(notif->ctx != prev_notif->ctx ||
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| 		     notif->task != prev_notif->task))
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| 		return -EEXIST;
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| 
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| 	nd->head = prev_nd->head;
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| 	nd->next = prev_nd->next;
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| 	prev_nd->next = nd;
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| 	net_zcopy_get(&nd->head->uarg);
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| 	return 0;
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| }
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| 
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| static const struct ubuf_info_ops io_ubuf_ops = {
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| 	.complete = io_tx_ubuf_complete,
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| 	.link_skb = io_link_skb,
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| };
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| 
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| struct io_kiocb *io_alloc_notif(struct io_ring_ctx *ctx)
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| 	__must_hold(&ctx->uring_lock)
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| {
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| 	struct io_kiocb *notif;
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| 	struct io_notif_data *nd;
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| 
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| 	if (unlikely(!io_alloc_req(ctx, ¬if)))
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| 		return NULL;
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| 	notif->opcode = IORING_OP_NOP;
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| 	notif->flags = 0;
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| 	notif->file = NULL;
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| 	notif->task = current;
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| 	io_get_task_refs(1);
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| 	notif->rsrc_node = NULL;
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| 
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| 	nd = io_notif_to_data(notif);
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| 	nd->zc_report = false;
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| 	nd->account_pages = 0;
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| 	nd->next = NULL;
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| 	nd->head = nd;
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| 
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| 	nd->uarg.flags = IO_NOTIF_UBUF_FLAGS;
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| 	nd->uarg.ops = &io_ubuf_ops;
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| 	refcount_set(&nd->uarg.refcnt, 1);
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| 	return notif;
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| }
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