From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6AD00C56201 for ; Thu, 22 Oct 2020 23:14:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 18EFD208B3 for ; Thu, 22 Oct 2020 23:14:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="EwUO9FtY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S373216AbgJVXOW (ORCPT ); Thu, 22 Oct 2020 19:14:22 -0400 Received: from aserp2130.oracle.com ([141.146.126.79]:59684 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S373279AbgJVXOW (ORCPT ); Thu, 22 Oct 2020 19:14:22 -0400 Received: from pps.filterd (aserp2130.oracle.com [127.0.0.1]) by aserp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 09MN9Cju035101; Thu, 22 Oct 2020 23:14:18 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : subject : date : message-id : in-reply-to : references; s=corp-2020-01-29; bh=8FKZy3A/j176SupR8eKH3+YbvD3moCfSOZVBwN3mb10=; b=EwUO9FtYF0Tx3Ho0xq/wz4oXmOcvxLf73PeQRLRrMrBagO3GUh9PRplLdwUR0IzW3kR2 piksicYJUXtwT2N46Byeduc6Co83Mu6m/SmcRmsJX6JmijhpKn7tz9D3CUMTVbVcYBRa +w0PkxpqYbLjv0mt4+Hy1yicDTXeVEfynFkafmFx8vVE1fP7/iOfQ/uULfk+JawGiuZF jg4OMremds46GmcGt9l0W4244ZzhQctIiM6um4t9nd8XHCoJQe/E7lX8KBIc2loKUtTS B6UBRlHccxzyKXWVY7Ne6hTXxiGuFszmPuPqEw7PlJLHfaux3y5FtBtBtn00gUvI48E8 QQ== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2130.oracle.com with ESMTP id 347p4b8nax-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 22 Oct 2020 23:14:18 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 09MN61mO084597; Thu, 22 Oct 2020 23:14:17 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userp3020.oracle.com with ESMTP id 34ak1aeqqc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 22 Oct 2020 23:14:17 +0000 Received: from abhmp0010.oracle.com (abhmp0010.oracle.com [141.146.116.16]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 09MNEG67022651; Thu, 22 Oct 2020 23:14:16 GMT Received: from ca-ldom147.us.oracle.com (/10.129.68.131) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 22 Oct 2020 16:14:16 -0700 From: Bijan Mottahedeh To: axboe@kernel.dk, io-uring@vger.kernel.org Subject: [RFC 4/8] io_uring: implement fixed buffers registration similar to fixed files Date: Thu, 22 Oct 2020 16:13:59 -0700 Message-Id: <1603408443-51303-5-git-send-email-bijan.mottahedeh@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1603408443-51303-1-git-send-email-bijan.mottahedeh@oracle.com> References: <1603408443-51303-1-git-send-email-bijan.mottahedeh@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9782 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=2 mlxscore=0 phishscore=0 spamscore=0 adultscore=0 mlxlogscore=999 malwarescore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010220148 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9782 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=2 priorityscore=1501 clxscore=1015 malwarescore=0 mlxscore=0 bulkscore=0 lowpriorityscore=0 phishscore=0 adultscore=0 mlxlogscore=999 impostorscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010220148 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Apply fixed_rsrc functionality for fixed buffers support. Signed-off-by: Bijan Mottahedeh --- fs/io_uring.c | 294 +++++++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 258 insertions(+), 36 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 1996c15..daf32d3 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -104,6 +104,14 @@ #define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \ IORING_REGISTER_LAST + IORING_OP_LAST) +/* + * Shift of 7 is 128 entries, or exactly one page on 64-bit archs + */ +#define IORING_BUF_TABLE_SHIFT 7 /* struct io_mapped_ubuf */ +#define IORING_MAX_BUFS_TABLE (1U << IORING_BUF_TABLE_SHIFT) +#define IORING_BUF_TABLE_MASK (IORING_MAX_BUFS_TABLE - 1) +#define IORING_MAX_FIXED_BUFS UIO_MAXIOV + struct io_uring { u32 head ____cacheline_aligned_in_smp; u32 tail ____cacheline_aligned_in_smp; @@ -337,8 +345,8 @@ struct io_ring_ctx { unsigned nr_user_files; /* if used, fixed mapped user buffers */ + struct fixed_rsrc_data *buf_data; unsigned nr_user_bufs; - struct io_mapped_ubuf *user_bufs; struct user_struct *user; @@ -400,6 +408,9 @@ struct io_ring_ctx { struct delayed_work file_put_work; struct llist_head file_put_llist; + struct delayed_work buf_put_work; + struct llist_head buf_put_llist; + struct work_struct exit_work; struct io_restriction restrictions; }; @@ -971,6 +982,7 @@ static struct file *io_file_get(struct io_submit_state *state, struct io_kiocb *req, int fd, bool fixed); static void __io_queue_sqe(struct io_kiocb *req, struct io_comp_state *cs); static void io_file_put_work(struct work_struct *work); +static void io_buf_put_work(struct work_struct *work); static ssize_t io_import_iovec(int rw, struct io_kiocb *req, struct iovec **iovec, struct iov_iter *iter, @@ -1179,6 +1191,8 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) INIT_LIST_HEAD(&ctx->inflight_list); INIT_DELAYED_WORK(&ctx->file_put_work, io_file_put_work); init_llist_head(&ctx->file_put_llist); + INIT_DELAYED_WORK(&ctx->buf_put_work, io_buf_put_work); + init_llist_head(&ctx->buf_put_llist); return ctx; err: if (ctx->fallback_req) @@ -2855,6 +2869,15 @@ static void kiocb_done(struct kiocb *kiocb, ssize_t ret, io_rw_done(kiocb, ret); } +static inline struct io_mapped_ubuf *io_buf_from_index(struct io_ring_ctx *ctx, + int index) +{ + struct fixed_rsrc_table *table; + + table = &ctx->buf_data->table[index >> IORING_BUF_TABLE_SHIFT]; + return &table->bufs[index & IORING_BUF_TABLE_MASK]; +} + static ssize_t io_import_fixed(struct io_kiocb *req, int rw, struct iov_iter *iter) { @@ -2865,10 +2888,15 @@ static ssize_t io_import_fixed(struct io_kiocb *req, int rw, size_t offset; u64 buf_addr; + /* attempt to use fixed buffers without having provided iovecs */ + if (unlikely(!ctx->buf_data)) + return -EFAULT; + + buf_index = req->buf_index; if (unlikely(buf_index >= ctx->nr_user_bufs)) return -EFAULT; index = array_index_nospec(buf_index, ctx->nr_user_bufs); - imu = &ctx->user_bufs[index]; + imu = io_buf_from_index(ctx, index); buf_addr = req->rw.addr; /* overflow */ @@ -7969,28 +7997,73 @@ static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries) return pages; } -static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx) +static void io_buffer_unmap(struct io_ring_ctx *ctx, struct io_mapped_ubuf *imu) { - int i, j; + unsigned i; - if (!ctx->user_bufs) - return -ENXIO; + for (i = 0; i < imu->nr_bvecs; i++) + unpin_user_page(imu->bvec[i].bv_page); - for (i = 0; i < ctx->nr_user_bufs; i++) { - struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; + if (imu->acct_pages) + io_unaccount_mem(ctx, imu->nr_bvecs, ACCT_PINNED); + kvfree(imu->bvec); + imu->nr_bvecs = 0; +} - for (j = 0; j < imu->nr_bvecs; j++) - unpin_user_page(imu->bvec[j].bv_page); +static void io_buffers_unmap(struct io_ring_ctx *ctx) +{ + unsigned i; + struct io_mapped_ubuf *imu; - if (imu->acct_pages) - io_unaccount_mem(ctx, imu->acct_pages, ACCT_PINNED); - kvfree(imu->bvec); - imu->nr_bvecs = 0; + for (i = 0; i < ctx->nr_user_bufs; i++) { + imu = io_buf_from_index(ctx, i); + io_buffer_unmap(ctx, imu); } +} + +static void io_buffers_map_free(struct io_ring_ctx *ctx) +{ + struct fixed_rsrc_data *data = ctx->buf_data; + unsigned nr_tables, i; + + if (!data) + return; - kfree(ctx->user_bufs); - ctx->user_bufs = NULL; + nr_tables = DIV_ROUND_UP(ctx->nr_user_bufs, IORING_MAX_BUFS_TABLE); + for (i = 0; i < nr_tables; i++) + kfree(data->table[i].bufs); + kfree(data->table); + percpu_ref_exit(&data->refs); + kfree(data); + ctx->buf_data = NULL; ctx->nr_user_bufs = 0; +} + +static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx) +{ + struct fixed_rsrc_data *data = ctx->buf_data; + struct fixed_rsrc_ref_node *ref_node = NULL; + + if (!data) + return -ENXIO; + + spin_lock(&data->lock); + if (!list_empty(&data->ref_list)) + ref_node = list_first_entry(&data->ref_list, + struct fixed_rsrc_ref_node, node); + spin_unlock(&data->lock); + if (ref_node) + percpu_ref_kill(&ref_node->refs); + + percpu_ref_kill(&data->refs); + + /* wait for all refs nodes to complete */ + flush_delayed_work(&ctx->buf_put_work); + wait_for_completion(&data->done); + + io_buffers_unmap(ctx); + io_buffers_map_free(ctx); + return 0; } @@ -8043,7 +8116,13 @@ static bool headpage_already_acct(struct io_ring_ctx *ctx, struct page **pages, /* check previously registered pages */ for (i = 0; i < ctx->nr_user_bufs; i++) { - struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; + struct fixed_rsrc_table *table; + struct io_mapped_ubuf *imu; + unsigned index; + + table = &ctx->buf_data->table[i >> IORING_BUF_TABLE_SHIFT]; + index = i & IORING_BUF_TABLE_MASK; + imu = &table->bufs[index]; for (j = 0; j < imu->nr_bvecs; j++) { if (!PageCompound(imu->bvec[j].bv_page)) @@ -8178,19 +8257,82 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov, return ret; } -static int io_buffers_map_alloc(struct io_ring_ctx *ctx, unsigned int nr_args) +static void io_free_buf_tables(struct fixed_rsrc_data *buf_data, + unsigned nr_tables) { - if (ctx->user_bufs) - return -EBUSY; - if (!nr_args || nr_args > UIO_MAXIOV) - return -EINVAL; + int i; - ctx->user_bufs = kcalloc(nr_args, sizeof(struct io_mapped_ubuf), - GFP_KERNEL); - if (!ctx->user_bufs) - return -ENOMEM; + for (i = 0; i < nr_tables; i++) { + struct fixed_rsrc_table *table = &buf_data->table[i]; + kfree(table->bufs); + } +} - return 0; +static int io_alloc_buf_tables(struct fixed_rsrc_data *buf_data, + unsigned nr_tables, unsigned nr_bufs) +{ + int i; + + for (i = 0; i < nr_tables; i++) { + struct fixed_rsrc_table *table = &buf_data->table[i]; + unsigned this_bufs; + + this_bufs = min(nr_bufs, IORING_MAX_BUFS_TABLE); + table->bufs = kcalloc(this_bufs, sizeof(struct io_mapped_ubuf), + GFP_KERNEL); + if (!table->bufs) + break; + nr_bufs -= this_bufs; + } + + if (i == nr_tables) + return 0; + + io_free_buf_tables(buf_data, nr_tables); + return 1; +} + +static struct fixed_rsrc_data *io_buffers_map_alloc(struct io_ring_ctx *ctx, + unsigned int nr_args) +{ + unsigned nr_tables; + struct fixed_rsrc_data *buf_data; + int ret = -ENOMEM; + + if (ctx->buf_data) + return ERR_PTR(-EBUSY); + if (!nr_args || nr_args > IORING_MAX_FIXED_BUFS) + return ERR_PTR(-EINVAL); + + buf_data = kzalloc(sizeof(*ctx->buf_data), GFP_KERNEL); + if (!buf_data) + return ERR_PTR(-ENOMEM); + buf_data->ctx = ctx; + init_completion(&buf_data->done); + INIT_LIST_HEAD(&buf_data->ref_list); + spin_lock_init(&buf_data->lock); + + nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_BUFS_TABLE); + buf_data->table = kcalloc(nr_tables, sizeof(buf_data->table), + GFP_KERNEL); + if (!buf_data->table) + goto out_free; + + if (percpu_ref_init(&buf_data->refs, io_rsrc_ref_kill, + PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) + goto out_free; + + if (io_alloc_buf_tables(buf_data, nr_tables, nr_args)) + goto out_ref; + + return buf_data; + +out_ref: + percpu_ref_exit(&buf_data->refs); +out_free: + kfree(buf_data->table); + kfree(buf_data); + return ERR_PTR(ret); } static int io_buffer_validate(struct iovec *iov) @@ -8210,39 +8352,119 @@ static int io_buffer_validate(struct iovec *iov) return 0; } +static void io_buf_put_work(struct work_struct *work) +{ + struct io_ring_ctx *ctx; + struct llist_node *node; + + ctx = container_of(work, struct io_ring_ctx, buf_put_work.work); + node = llist_del_all(&ctx->buf_put_llist); + io_rsrc_put_work(node); +} + +static void io_buf_data_ref_zero(struct percpu_ref *ref) +{ + struct fixed_rsrc_ref_node *ref_node; + struct io_ring_ctx *ctx; + bool first_add; + int delay = HZ; + + ref_node = container_of(ref, struct fixed_rsrc_ref_node, refs); + ctx = ref_node->rsrc_data->ctx; + + if (percpu_ref_is_dying(&ctx->buf_data->refs)) + delay = 0; + + first_add = llist_add(&ref_node->llist, &ctx->buf_put_llist); + if (!delay) + mod_delayed_work(system_wq, &ctx->buf_put_work, 0); + else if (first_add) + queue_delayed_work(system_wq, &ctx->buf_put_work, delay); +} + +static void io_ring_buf_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc) +{ + io_buffer_unmap(ctx, prsrc->buf); +} + +static struct fixed_rsrc_ref_node *alloc_fixed_buf_ref_node( + struct io_ring_ctx *ctx) +{ + struct fixed_rsrc_ref_node *ref_node; + + ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL); + if (!ref_node) + return ERR_PTR(-ENOMEM); + + if (percpu_ref_init(&ref_node->refs, io_buf_data_ref_zero, + 0, GFP_KERNEL)) { + kfree(ref_node); + return ERR_PTR(-ENOMEM); + } + INIT_LIST_HEAD(&ref_node->node); + INIT_LIST_HEAD(&ref_node->rsrc_list); + ref_node->rsrc_data = ctx->buf_data; + ref_node->rsrc_put = io_ring_buf_put; + return ref_node; +} + static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, unsigned int nr_args) { int i, ret; struct iovec iov; struct page *last_hpage = NULL; + struct fixed_rsrc_ref_node *ref_node; + struct fixed_rsrc_data *buf_data; - ret = io_buffers_map_alloc(ctx, nr_args); - if (ret) - return ret; + buf_data = io_buffers_map_alloc(ctx, nr_args); + if (IS_ERR(buf_data)) + return PTR_ERR(buf_data); - for (i = 0; i < nr_args; i++) { - struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; + for (i = 0; i < nr_args; i++, ctx->nr_user_bufs++) { + struct fixed_rsrc_table *table; + struct io_mapped_ubuf *imu; + unsigned index; ret = io_copy_iov(ctx, &iov, arg, i); if (ret) break; + /* allow sparse sets */ + if (!iov.iov_base && !iov.iov_len) + continue; + ret = io_buffer_validate(&iov); if (ret) break; + table = &buf_data->table[i >> IORING_BUF_TABLE_SHIFT]; + index = i & IORING_BUF_TABLE_MASK; + imu = &table->bufs[index]; + ret = io_sqe_buffer_register(ctx, &iov, imu, &last_hpage); if (ret) break; + } - ctx->nr_user_bufs++; + ctx->buf_data = buf_data; + if (ret) { + io_sqe_buffers_unregister(ctx); + return ret; } - if (ret) + ref_node = alloc_fixed_buf_ref_node(ctx); + if (IS_ERR(ref_node)) { io_sqe_buffers_unregister(ctx); + return PTR_ERR(ref_node); + } - return ret; + buf_data->node = ref_node; + spin_lock(&buf_data->lock); + list_add(&ref_node->node, &buf_data->ref_list); + spin_unlock(&buf_data->lock); + percpu_ref_get(&buf_data->refs); + return 0; } static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg) @@ -9056,7 +9278,7 @@ static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m) } seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs); for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) { - struct io_mapped_ubuf *buf = &ctx->user_bufs[i]; + struct io_mapped_ubuf *buf = io_buf_from_index(ctx, i); seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, (unsigned int) buf->len); -- 1.8.3.1