From patchwork Fri Mar 17 07:15:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Uladzislau Rezki X-Patchwork-Id: 13178607 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA3ECC74A5B for ; Fri, 17 Mar 2023 07:16:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230089AbjCQHQI (ORCPT ); Fri, 17 Mar 2023 03:16:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42302 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230182AbjCQHQH (ORCPT ); Fri, 17 Mar 2023 03:16:07 -0400 Received: from mail-ed1-x531.google.com (mail-ed1-x531.google.com [IPv6:2a00:1450:4864:20::531]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 850AF10CD; Fri, 17 Mar 2023 00:16:02 -0700 (PDT) Received: by mail-ed1-x531.google.com with SMTP id z21so16809239edb.4; Fri, 17 Mar 2023 00:16:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1679037361; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=KShndDmtpL/wghNsEWsMIclWE+/Ioe4uetwa8XAxyPI=; b=XiSV7Xe+j4vAxn8Wn4s4HU1BPZR7kJx3q/rQBuzCQwnmSdrOu9xRPQuKrmRBH4cLCL KGgGVXCXRSCwoIjqKs3+JX+kLFft3tK1u0CNFBcx0hrgCN2VLx8nutygse61czoRwx60 Yr3FOjsEdDu2qv/SrKqGepBb6tdPnXvPpPid4Y4KRZvdfH/yNDjcyGDCvwQl11CK+Hpc QkcJRYb3LPv1A+PAZEN35erFcLIeH5WrWoDIY0GQ5fGOH/MHhz/H9jXlVjPT4DBassN7 LYj3b8Cw6apyNBXUXPxv4P2ekzd6pe5n0IQlG6j8mA9Qrt4iBXeMJBvSXW0G7IfcZGLU 69Og== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679037361; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=KShndDmtpL/wghNsEWsMIclWE+/Ioe4uetwa8XAxyPI=; b=x3PtkVDHznsiLizYHMXW/U5x0aTCsIfh1QIX1sY9BQ74zfjs2SSZpysO0a0MhtGRk9 FpwEMVLgnnO+FzMKwDjzWwwRQ+cGXkwwuxnNTzk7ob9JxQD53eQA167ptS//Vmt8HYuw ONfe2Z3SIE9i6T/oP4bfmwfQcE00zH03+gv+7OdEaK1ipIEOj8Hmjrrq7EcjDKDd3rUO dH+vDyYp4xT7OR3vzTUQfemBKKhLDkyYJt557grvl9hjzAq0ZDnKQgM8/A7cEnLkZ8SD MEfSYxXuu9I84WYgy2jBK/x8QTLMfvh7I8OV+/aIY/NuHQz3KU2MmGYYuOq50fGFXl1A 16UQ== X-Gm-Message-State: AO0yUKWDN1i3R/fsy00F2w5yvR4ILpU93PJ7Zq/CDrXZG4n8KFccC29V 5wFE3l/pJeufIxIK5l7jTns= X-Google-Smtp-Source: AK7set+da5nkPqUZwzrH2N9wTQTxnlUyt76NtDfl5j2HdB/nXGh1aTJTyVPIsUDpF3PTPRvTj4A8WQ== X-Received: by 2002:a05:6402:44b:b0:4fa:eccd:9849 with SMTP id p11-20020a056402044b00b004faeccd9849mr2011896edw.9.1679037360872; Fri, 17 Mar 2023 00:16:00 -0700 (PDT) Received: from pc638.lan ([155.137.26.201]) by smtp.gmail.com with ESMTPSA id i23-20020a508717000000b004af6c5f1805sm642321edb.52.2023.03.17.00.16.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Mar 2023 00:16:00 -0700 (PDT) From: "Uladzislau Rezki (Sony)" To: Theodore Ts'o , Joel Fernandes Cc: RCU , "Paul E . McKenney" , LKML , Uladzislau Rezki , Oleksiy Avramchenko , Steven Rostedt , Frederic Weisbecker , linux-ext4@vger.kernel.org, Lukas Czerner , Andreas Dilger Subject: [PATCH 1/1] ext4: Replace ext4_kvfree_array_rcu() by kvfree_rcu_mightsleep() Date: Fri, 17 Mar 2023 08:15:58 +0100 Message-Id: <20230317071558.335645-1-urezki@gmail.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org The ext4_kvfree_array_rcu() function was introduced in order to release some memory after a grace period during resizing of a partition. An object that is freed does not contain any rcu_head filed. To do so, it requires to allocate some extra memory for a special structure that has an rcu_head filed and pointer one where a freed memory is attached. Finally call_rcu() API is invoked. Since we have a single argument of kvfree_rcu() API, we can easily replace all that tricky code by one single call that does the same but in more efficient way. Cc: linux-ext4@vger.kernel.org Cc: Lukas Czerner Cc: Andreas Dilger Signed-off-by: Uladzislau Rezki (Sony) Reviewed-by: Paul E. McKenney --- fs/ext4/ext4.h | 1 - fs/ext4/mballoc.c | 2 +- fs/ext4/resize.c | 31 ++----------------------------- fs/ext4/super.c | 2 +- 4 files changed, 4 insertions(+), 32 deletions(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 140e1eb300d1..e43d1a2d175e 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -3057,7 +3057,6 @@ extern int ext4_generic_delete_entry(struct inode *dir, extern bool ext4_empty_dir(struct inode *inode); /* resize.c */ -extern void ext4_kvfree_array_rcu(void *to_free); extern int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input); extern int ext4_group_extend(struct super_block *sb, diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 5b2ae37a8b80..96b4e3317640 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -3055,7 +3055,7 @@ int ext4_mb_alloc_groupinfo(struct super_block *sb, ext4_group_t ngroups) rcu_assign_pointer(sbi->s_group_info, new_groupinfo); sbi->s_group_info_size = size / sizeof(*sbi->s_group_info); if (old_groupinfo) - ext4_kvfree_array_rcu(old_groupinfo); + kvfree_rcu_mightsleep(old_groupinfo); ext4_debug("allocated s_groupinfo array for %d meta_bg's\n", sbi->s_group_info_size); return 0; diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 6b91443d6bf3..330b81f36e10 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -18,33 +18,6 @@ #include "ext4_jbd2.h" -struct ext4_rcu_ptr { - struct rcu_head rcu; - void *ptr; -}; - -static void ext4_rcu_ptr_callback(struct rcu_head *head) -{ - struct ext4_rcu_ptr *ptr; - - ptr = container_of(head, struct ext4_rcu_ptr, rcu); - kvfree(ptr->ptr); - kfree(ptr); -} - -void ext4_kvfree_array_rcu(void *to_free) -{ - struct ext4_rcu_ptr *ptr = kzalloc(sizeof(*ptr), GFP_KERNEL); - - if (ptr) { - ptr->ptr = to_free; - call_rcu(&ptr->rcu, ext4_rcu_ptr_callback); - return; - } - synchronize_rcu(); - kvfree(to_free); -} - int ext4_resize_begin(struct super_block *sb) { struct ext4_sb_info *sbi = EXT4_SB(sb); @@ -931,7 +904,7 @@ static int add_new_gdb(handle_t *handle, struct inode *inode, n_group_desc[gdb_num] = gdb_bh; rcu_assign_pointer(EXT4_SB(sb)->s_group_desc, n_group_desc); EXT4_SB(sb)->s_gdb_count++; - ext4_kvfree_array_rcu(o_group_desc); + kvfree_rcu_mightsleep(o_group_desc); lock_buffer(EXT4_SB(sb)->s_sbh); le16_add_cpu(&es->s_reserved_gdt_blocks, -1); @@ -994,7 +967,7 @@ static int add_new_gdb_meta_bg(struct super_block *sb, rcu_assign_pointer(EXT4_SB(sb)->s_group_desc, n_group_desc); EXT4_SB(sb)->s_gdb_count++; - ext4_kvfree_array_rcu(o_group_desc); + kvfree_rcu_mightsleep(o_group_desc); return err; } diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 87aa23d047c9..34d802848d6d 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3108,7 +3108,7 @@ int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup) rcu_assign_pointer(sbi->s_flex_groups, new_groups); sbi->s_flex_groups_allocated = size; if (old_groups) - ext4_kvfree_array_rcu(old_groups); + kvfree_rcu_mightsleep(old_groups); return 0; }