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[188.28.125.106]) by smtp.gmail.com with ESMTPSA id c14-20020a7bc00e000000b003a044fe7fe7sm89833wmb.9.2022.07.12.13.53.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Jul 2022 13:53:28 -0700 (PDT) From: Pavel Begunkov To: io-uring@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: "David S . Miller" , Jakub Kicinski , Jonathan Lemon , Willem de Bruijn , Jens Axboe , David Ahern , kernel-team@fb.com, Pavel Begunkov Subject: [PATCH net-next v5 18/27] io_uring: add notification slot registration Date: Tue, 12 Jul 2022 21:52:42 +0100 Message-Id: X-Mailer: git-send-email 2.37.0 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Let the userspace to register and unregister notification slots. Signed-off-by: Pavel Begunkov --- include/uapi/linux/io_uring.h | 17 ++++++++++++++ io_uring/io_uring.c | 9 ++++++++ io_uring/notif.c | 43 +++++++++++++++++++++++++++++++++++ io_uring/notif.h | 3 +++ 4 files changed, 72 insertions(+) diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index e858dba2e6c9..f1ba8e934168 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -454,6 +454,10 @@ enum { /* register a range of fixed file slots for automatic slot allocation */ IORING_REGISTER_FILE_ALLOC_RANGE = 25, + /* zerocopy notification API */ + IORING_REGISTER_NOTIFIERS = 26, + IORING_UNREGISTER_NOTIFIERS = 27, + /* this goes last */ IORING_REGISTER_LAST }; @@ -500,6 +504,19 @@ struct io_uring_rsrc_update2 { __u32 resv2; }; +struct io_uring_notification_slot { + __u64 tag; + __u64 resv[3]; +}; + +struct io_uring_notification_register { + __u32 nr_slots; + __u32 resv; + __u64 resv2; + __u64 data; + __u64 resv3; +}; + /* Skip updating fd indexes set to this value in the fd table */ #define IORING_REGISTER_FILES_SKIP (-2) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index bdc5a2839d94..41ef98a43d32 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -3875,6 +3875,15 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, break; ret = io_register_file_alloc_range(ctx, arg); break; + case IORING_REGISTER_NOTIFIERS: + ret = io_notif_register(ctx, arg, nr_args); + break; + case IORING_UNREGISTER_NOTIFIERS: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_notif_unregister(ctx); + break; default: ret = -EINVAL; break; diff --git a/io_uring/notif.c b/io_uring/notif.c index 0a2e98bd74f6..e6d98dc208c7 100644 --- a/io_uring/notif.c +++ b/io_uring/notif.c @@ -162,5 +162,48 @@ __cold int io_notif_unregister(struct io_ring_ctx *ctx) kvfree(ctx->notif_slots); ctx->notif_slots = NULL; ctx->nr_notif_slots = 0; + io_notif_cache_purge(ctx); + return 0; +} + +__cold int io_notif_register(struct io_ring_ctx *ctx, + void __user *arg, unsigned int size) + __must_hold(&ctx->uring_lock) +{ + struct io_uring_notification_slot __user *slots; + struct io_uring_notification_slot slot; + struct io_uring_notification_register reg; + unsigned i; + + if (ctx->nr_notif_slots) + return -EBUSY; + if (size != sizeof(reg)) + return -EINVAL; + if (copy_from_user(®, arg, sizeof(reg))) + return -EFAULT; + if (!reg.nr_slots || reg.nr_slots > IORING_MAX_NOTIF_SLOTS) + return -EINVAL; + if (reg.resv || reg.resv2 || reg.resv3) + return -EINVAL; + + slots = u64_to_user_ptr(reg.data); + ctx->notif_slots = kvcalloc(reg.nr_slots, sizeof(ctx->notif_slots[0]), + GFP_KERNEL_ACCOUNT); + if (!ctx->notif_slots) + return -ENOMEM; + + for (i = 0; i < reg.nr_slots; i++, ctx->nr_notif_slots++) { + struct io_notif_slot *notif_slot = &ctx->notif_slots[i]; + + if (copy_from_user(&slot, &slots[i], sizeof(slot))) { + io_notif_unregister(ctx); + return -EFAULT; + } + if (slot.resv[0] | slot.resv[1] | slot.resv[2]) { + io_notif_unregister(ctx); + return -EINVAL; + } + notif_slot->tag = slot.tag; + } return 0; } diff --git a/io_uring/notif.h b/io_uring/notif.h index 1dd48efb7744..00efe164bdc4 100644 --- a/io_uring/notif.h +++ b/io_uring/notif.h @@ -6,6 +6,7 @@ #include #define IO_NOTIF_SPLICE_BATCH 32 +#define IORING_MAX_NOTIF_SLOTS (1U << 10) struct io_notif { struct ubuf_info uarg; @@ -48,6 +49,8 @@ struct io_notif_slot { u32 seq; }; +int io_notif_register(struct io_ring_ctx *ctx, + void __user *arg, unsigned int size); int io_notif_unregister(struct io_ring_ctx *ctx); void io_notif_cache_purge(struct io_ring_ctx *ctx);