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 Received: from lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8121BC624CE for ; Mon, 31 Aug 2026 09:23:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.sourceforge.net; s=beta; h=Content-Transfer-Encoding:Content-Type:Cc: Reply-To:From:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Subject:MIME-Version:References:In-Reply-To: Message-ID:Date:To:Sender:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ud7dqsvtBM37BSJ3tAfljfYXlpDHQgYO+4ie/XruOrA=; b=JaXbd8F5kckeVAMywb3h2xbNbo r4J0xNQH6pmDQANTBWRpLNzUgIRMMLg70PE031pLvxUl6c6iTmZo+imoOAgVXC5WLESdkZvDuV6+z Opr+uWJyjGcsUcMmLs9bXhyK426UWIghoohPdISfKA8VVWTX74iT0tJ4+BTkE3H7TuOI=; Received: from [127.0.0.1] (helo=sfs-ml-2.v29.lw.sourceforge.com) by sfs-ml-2.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1x0yEJ-0002pY-Bu; Mon, 31 Aug 2026 09:23:04 +0000 Received: from [172.30.29.66] (helo=mx.sourceforge.net) by sfs-ml-2.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1x0yE7-0002of-Cf for linux-f2fs-devel@lists.sourceforge.net; Mon, 31 Aug 2026 09:22:52 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=SI4x8+sRvqbz00eaGmxdSC4dW0fxIb9yXDSu8BnZxCU=; b=etmLmGLSy192UglSS1JMIr8Vpa DLw2D/cY8h+QilzCwDF1tRXfi0mvaIMK44Tlf0f+fhj7MUXTSoDy8ZybPFzUnryFkWVZ19fgVS+1X 9BJm7DUaB4G3HMG4yUvsONxfmckz/o6WF7JvNRqgC21SxTXmmbiAVI+BAkYknb2a6qQI=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID: Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=SI4x8+sRvqbz00eaGmxdSC4dW0fxIb9yXDSu8BnZxCU=; b=CkCUQOgyaLGiQr+WEPcqphozvC f9fRakzD4owyZiiNv6S5reSRg2kqD3QW++HAu3fELL8H9eCTFBddgvwZVVplhamhVjpdTr9dYa7/z TRhP2aNpVWzsZuRHuGCutyZni4lZMNGTLrl6wvHtlmkWIBUK3/TL05GmZGyikV/RM37M=; Received: from sea.source.kernel.org ([172.234.252.31]) by sfi-mx-1.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.95) id 1x0yE6-0006yO-Ik for linux-f2fs-devel@lists.sourceforge.net; Mon, 31 Aug 2026 09:22:52 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 4F30443EA2 for ; Mon, 31 Aug 2026 09:22:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5DDC11F00ACA; Mon, 31 Aug 2026 09:22:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788168165; bh=SI4x8+sRvqbz00eaGmxdSC4dW0fxIb9yXDSu8BnZxCU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=NhVZHRp/UpaN7azo9v1Mm0Hp26NnVPKjbI0KJRd5RAE3tfqNVGEMB0ySdLvKE6uAW Bfla3Du4F9jE+i01CJn2wOV2feF+/2a1ElRwIUVhHhsVskrTRTt9lDqRDJC1v97F/H /AaXrYD9LFYOhSPAbXrdNJKTm19TJO0jGcvm08I2e6j4eL4DVaTAvtN9rnRCEla0UB BR060KoMOPBv7IGSIuRJPuZI8qs5i9rzg8JfxvqX9KHkCNfgm0ZfGJJ0r5gOlxJGQj QOIBFkJxsGje7PGyk0C8bgiVFafUWpK5NPzaCAjCuqduFlPsmMI5pvMNUitnRwN/au xqXsScNCtgAnw== To: jaegeuk@kernel.org Date: Mon, 31 Aug 2026 17:22:19 +0800 Message-ID: <20260831092227.739737-5-chao@kernel.org> X-Mailer: git-send-email 2.55.0.897.gb25b4bd76c-goog In-Reply-To: <20260831092227.739737-1-chao@kernel.org> References: <20260831092227.739737-1-chao@kernel.org> MIME-Version: 1.0 X-Headers-End: 1x0yE6-0006yO-Ik Subject: [f2fs-dev] [PATCH v5 04/12] f2fs: cache: introduce writeback thread X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Chao Yu via Linux-f2fs-devel Reply-To: Chao Yu Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net From: Chao Yu This patch introduces a background writeback kthread (f2fs_writeback-x:y) to periodically flush dirty metadata cache entries with a default interval of 5 seconds. It manages thread lifecycle across mount, unmount, and remount (rw/ro) transitions. It introduces a sysfs entry /sys/fs/f2fs//cache_wb_interval to control writeback interval. Signed-off-by: Chao Yu --- Documentation/ABI/testing/sysfs-fs-f2fs | 6 +++ fs/f2fs/cache.c | 56 +++++++++++++++++++++++++ fs/f2fs/cache.h | 12 ++++++ fs/f2fs/f2fs.h | 3 ++ fs/f2fs/super.c | 31 +++++++++++++- fs/f2fs/sysfs.c | 13 +++++- 6 files changed, 119 insertions(+), 2 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs index 0cebc89799dd..d2665b7f1f14 100644 --- a/Documentation/ABI/testing/sysfs-fs-f2fs +++ b/Documentation/ABI/testing/sysfs-fs-f2fs @@ -1020,3 +1020,9 @@ Contact: "Daeho Jeong" Description: This is a read-only entry to show the upper bound section number for pinned files. Pinned files will only be allocated within sections 0 to pinned_area_max_secno - 1. + +What: /sys/fs/f2fs//cache_wb_interval +Date: August 2026 +Contact: "Chao Yu" +Description: This is a writable entry to control writeback interval of + f2fs_writeback-x:y, by default the value is 5000, unit is ms. diff --git a/fs/f2fs/cache.c b/fs/f2fs/cache.c index ace2d7d42529..18133ca3f82b 100644 --- a/fs/f2fs/cache.c +++ b/fs/f2fs/cache.c @@ -631,3 +631,59 @@ unsigned long f2fs_shrink_cache(struct f2fs_sb_info *sbi, { return f2fs_do_shrink_cache(META_CACHE(sbi), nr_to_scan); } + +static int f2fs_cache_writeback_kthread(void *data) +{ + struct f2fs_sb_info *sbi = data; + struct f2fs_cache_kthread *cache_thread = &sbi->cache_thread; + wait_queue_head_t *wq = &cache_thread->cache_wb_wq; + unsigned int interval = cache_thread->cache_wb_interval; + + set_freezable(); + + while (!kthread_should_stop()) { + wait_event_freezable_timeout(*wq, + kthread_should_stop(), + msecs_to_jiffies(interval)); + + if (kthread_should_stop()) + break; + if (f2fs_cp_error(sbi)) + continue; + } + return 0; +} + +int f2fs_start_cache_wb_thread(struct f2fs_sb_info *sbi) +{ + struct f2fs_cache_kthread *cache_thread = &sbi->cache_thread; + struct task_struct *task; + dev_t dev = sbi->sb->s_dev; + char name[36]; + + if (cache_thread->cache_wb_task) + return 0; + + init_waitqueue_head(&cache_thread->cache_wb_wq); + snprintf(name, sizeof(name), "f2fs_writeback-%u:%u", + MAJOR(dev), MINOR(dev)); + + task = kthread_run(f2fs_cache_writeback_kthread, sbi, "%s", name); + if (IS_ERR(task)) + return PTR_ERR(task); + + cache_thread->cache_wb_task = task; + cache_thread->cache_wb_interval = DEF_DIRTY_CACHE_TIMEOUT; + return 0; +} + +void f2fs_stop_cache_wb_thread(struct f2fs_sb_info *sbi) +{ + struct f2fs_cache_kthread *cache_thread = &sbi->cache_thread; + + if (!cache_thread->cache_wb_task) + return; + + kthread_stop(cache_thread->cache_wb_task); + cache_thread->cache_wb_task = NULL; +} diff --git a/fs/f2fs/cache.h b/fs/f2fs/cache.h index 801e0955a3b0..6b9c7808699d 100644 --- a/fs/f2fs/cache.h +++ b/fs/f2fs/cache.h @@ -206,4 +206,16 @@ void f2fs_stop_cache_wb_thread(struct f2fs_sb_info *sbi); unsigned long f2fs_shrink_cache(struct f2fs_sb_info *sbi, unsigned long nr_to_scan); +#define DEF_DIRTY_CACHE_TIMEOUT 5000 + +struct f2fs_cache_kthread { + struct task_struct *cache_wb_task; + wait_queue_head_t cache_wb_wq; + atomic_t cache_wb_trigger; + unsigned int cache_wb_interval; +}; + +int f2fs_start_cache_wb_thread(struct f2fs_sb_info *sbi); +void f2fs_stop_cache_wb_thread(struct f2fs_sb_info *sbi); + #endif /* _LINUX_F2FS_CACHE_H */ diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 38027711f2f8..4f7909757cfc 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -2110,6 +2110,9 @@ struct f2fs_sb_info { /* f2fs internal cache */ struct f2fs_cached_block_list meta_blocks; + + /* internal cache flush thread */ + struct f2fs_cache_kthread cache_thread; }; /* Definitions to access f2fs_sb_info */ diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 858bd36f5f1b..7538648801e2 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -2026,6 +2026,7 @@ static void f2fs_put_super(struct super_block *sb) * flush all issued checkpoints and stop checkpoint issue thread. * after then, all checkpoints should be done by each process context. */ + f2fs_stop_cache_wb_thread(sbi); f2fs_stop_ckpt_thread(sbi); /* @@ -2832,6 +2833,7 @@ static int __f2fs_remount(struct fs_context *fc, struct super_block *sb) unsigned int flags = fc->sb_flags; int err; bool need_restart_gc = false, need_stop_gc = false; + bool need_restart_wb = false, need_stop_wb = false; bool need_restart_flush = false, need_stop_flush = false; bool need_restart_discard = false, need_stop_discard = false; bool need_enable_checkpoint = false, need_disable_checkpoint = false; @@ -2990,6 +2992,18 @@ static int __f2fs_remount(struct fs_context *fc, struct super_block *sb) need_stop_gc = true; } + if (flags & SB_RDONLY) { + if (sbi->cache_thread.cache_wb_task) { + f2fs_stop_cache_wb_thread(sbi); + need_restart_wb = true; + } + } else if (!sbi->cache_thread.cache_wb_task) { + err = f2fs_start_cache_wb_thread(sbi); + if (err) + goto restore_gc; + need_stop_wb = true; + } + if (flags & SB_RDONLY) { sync_inodes_sb(sb); @@ -3012,7 +3026,7 @@ static int __f2fs_remount(struct fs_context *fc, struct super_block *sb) } else { err = f2fs_create_flush_cmd_control(sbi); if (err) - goto restore_gc; + goto restore_wb; need_stop_flush = true; } @@ -3109,6 +3123,13 @@ static int __f2fs_remount(struct fs_context *fc, struct super_block *sb) clear_opt(sbi, FLUSH_MERGE); f2fs_destroy_flush_cmd_control(sbi, false); } +restore_wb: + if (need_restart_wb) { + if (f2fs_start_cache_wb_thread(sbi)) + f2fs_warn(sbi, "background cache writeback thread has stopped"); + } else if (need_stop_wb) { + f2fs_stop_cache_wb_thread(sbi); + } restore_gc: if (need_restart_gc) { if (f2fs_start_gc_thread(sbi)) @@ -5497,6 +5518,12 @@ static int f2fs_fill_super(struct super_block *sb, struct fs_context *fc) goto sync_free_meta; } + if (!f2fs_readonly(sb)) { + err = f2fs_start_cache_wb_thread(sbi); + if (err) + goto stop_gc_thread; + } + /* recover broken superblock */ if (recovery) { err = f2fs_commit_super(sbi, true); @@ -5519,6 +5546,8 @@ static int f2fs_fill_super(struct super_block *sb, struct fs_context *fc) sbi->umount_lock_holder = NULL; return 0; +stop_gc_thread: + f2fs_stop_gc_thread(sbi); sync_free_meta: /* safe to flush all the data */ sync_filesystem(sbi->sb); diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c index 811e350a1430..a9e8e0456ef5 100644 --- a/fs/f2fs/sysfs.c +++ b/fs/f2fs/sysfs.c @@ -40,6 +40,7 @@ enum { RESERVED_BLOCKS, /* struct f2fs_sb_info */ CPRC_INFO, /* struct ckpt_req_control */ ATGC_INFO, /* struct atgc_management */ + WB_THREAD, /* struct f2fs_cache_kthread */ }; static const char *gc_mode_names[MAX_GC_MODE] = { @@ -98,6 +99,8 @@ static unsigned char *__struct_ptr(struct f2fs_sb_info *sbi, int struct_type) return (unsigned char *)&sbi->cprc_info; else if (struct_type == ATGC_INFO) return (unsigned char *)&sbi->am; + else if (struct_type == WB_THREAD) + return (unsigned char *)&sbi->cache_thread; return NULL; } @@ -1008,7 +1011,8 @@ static ssize_t f2fs_sbi_store(struct f2fs_attr *a, bool gc_entry = (!strcmp(a->attr.name, "gc_urgent") || a->struct_type == GC_THREAD); bool thread_entry = !strcmp(a->attr.name, "ckpt_thread_ioprio") || - !strcmp(a->attr.name, "critical_task_priority"); + !strcmp(a->attr.name, "critical_task_priority") || + !strcmp(a->attr.name, "cache_wb_interval"); if (gc_entry || thread_entry) { if (!down_read_trylock(&sbi->sb->s_umount)) @@ -1218,6 +1222,9 @@ static struct f2fs_attr f2fs_attr_##name = __ATTR(name, 0444, name##_show, NULL) #define ATGC_INFO_RW_ATTR(name, elname) \ F2FS_RW_ATTR(ATGC_INFO, atgc_management, name, elname) +#define WB_THREAD_RW_ATTR(name, elname) \ + F2FS_RW_ATTR(WB_THREAD, f2fs_cache_kthread, name, elname) + /* GC_THREAD ATTR */ GC_THREAD_RW_ATTR(gc_urgent_sleep_time, urgent_sleep_time); GC_THREAD_RW_ATTR(gc_min_sleep_time, min_sleep_time); @@ -1347,6 +1354,9 @@ ATGC_INFO_RW_ATTR(atgc_candidate_count, max_candidate_count); ATGC_INFO_RW_ATTR(atgc_age_weight, age_weight); ATGC_INFO_RW_ATTR(atgc_age_threshold, age_threshold); +/* WB_THREAD ATTR */ +WB_THREAD_RW_ATTR(cache_wb_interval, cache_wb_interval); + F2FS_GENERAL_RO_ATTR(dirty_segments); F2FS_GENERAL_RO_ATTR(free_segments); F2FS_GENERAL_RO_ATTR(ovp_segments); @@ -1533,6 +1543,7 @@ static struct attribute *f2fs_attrs[] = { ATTR_LIST(lock_duration_priority), ATTR_LIST(adjust_lock_priority), ATTR_LIST(critical_task_priority), + ATTR_LIST(cache_wb_interval), NULL, }; ATTRIBUTE_GROUPS(f2fs); -- 2.49.0 _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel