From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on gnuweeb.org X-Spam-Level: X-Spam-Status: No, score=1.0 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_SOFTFAIL,UNPARSEABLE_RELAY autolearn=no autolearn_force=no version=3.4.6 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B8422C433F5 for ; Fri, 27 May 2022 16:53:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233988AbiE0Qxn (ORCPT ); Fri, 27 May 2022 12:53:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59498 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236944AbiE0Qxn (ORCPT ); Fri, 27 May 2022 12:53:43 -0400 Received: from out30-56.freemail.mail.aliyun.com (out30-56.freemail.mail.aliyun.com [115.124.30.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C4AAED70E for ; Fri, 27 May 2022 09:53:39 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R171e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04423;MF=xiaoguang.wang@linux.alibaba.com;NM=1;PH=DS;RN=3;SR=0;TI=SMTPD_---0VEXwEoG_1653670415; Received: from localhost(mailfrom:xiaoguang.wang@linux.alibaba.com fp:SMTPD_---0VEXwEoG_1653670415) by smtp.aliyun-inc.com(127.0.0.1); Sat, 28 May 2022 00:53:35 +0800 From: Xiaoguang Wang To: io-uring@vger.kernel.org Cc: axboe@kernel.dk, asml.silence@gmail.com Subject: [PATCH 2/2] io_uring: defer alloc_hint update to io_file_bitmap_set() Date: Sat, 28 May 2022 00:53:33 +0800 Message-Id: <20220527165333.55212-3-xiaoguang.wang@linux.alibaba.com> X-Mailer: git-send-email 2.14.4.44.g2045bb6 In-Reply-To: <20220527165333.55212-1-xiaoguang.wang@linux.alibaba.com> References: <20220527165333.55212-1-xiaoguang.wang@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org io_file_bitmap_get() returns a free bitmap slot, but if it isn't used later, such as io_queue_rsrc_removal() returns error, in this case, we should not update alloc_hint at all, which still should be considered as a valid candidate for next io_file_bitmap_get() calls. To fix this issue, only update alloc_hint in io_file_bitmap_set(). Signed-off-by: Xiaoguang Wang --- fs/io_uring.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index ff50e5f1753d..811007e055c6 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -5419,15 +5419,11 @@ static int io_file_bitmap_get(struct io_ring_ctx *ctx) unsigned long nr = ctx->nr_user_files; int ret; - if (table->alloc_hint >= nr) - table->alloc_hint = 0; - do { ret = find_next_zero_bit(table->bitmap, nr, table->alloc_hint); - if (ret != nr) { - table->alloc_hint = ret + 1; + if (ret != nr) return ret; - } + if (!table->alloc_hint) break; @@ -9650,12 +9646,15 @@ static void io_free_file_tables(struct io_file_table *table) table->bitmap = NULL; } -static inline void io_file_bitmap_set(struct io_file_table *table, int bit) +static inline void io_file_bitmap_set(struct io_ring_ctx *ctx, int bit) { + struct io_file_table *table = &ctx->file_table; + WARN_ON_ONCE(test_bit(bit, table->bitmap)); __set_bit(bit, table->bitmap); - if (bit == table->alloc_hint) - table->alloc_hint++; + table->alloc_hint = bit + 1; + if (table->alloc_hint >= ctx->nr_user_files) + table->alloc_hint = 0; } static inline void io_file_bitmap_clear(struct io_file_table *table, int bit) @@ -10080,7 +10079,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, } file_slot = io_fixed_file_slot(&ctx->file_table, i); io_fixed_file_set(file_slot, file); - io_file_bitmap_set(&ctx->file_table, i); + io_file_bitmap_set(ctx, i); } io_rsrc_node_switch(ctx, NULL); @@ -10161,7 +10160,7 @@ static int io_install_fixed_file(struct io_kiocb *req, unsigned int issue_flags, if (!ret) { *io_get_tag_slot(ctx->file_data, slot_index) = 0; io_fixed_file_set(file_slot, file); - io_file_bitmap_set(&ctx->file_table, slot_index); + io_file_bitmap_set(ctx, slot_index); } err: if (needs_switch) @@ -10284,7 +10283,7 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx, } *io_get_tag_slot(data, i) = tag; io_fixed_file_set(file_slot, file); - io_file_bitmap_set(&ctx->file_table, i); + io_file_bitmap_set(ctx, i); } } -- 2.14.4.44.g2045bb6