{"id":2225998,"url":"http://patchwork.ozlabs.org/api/1.2/patches/2225998/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-ext4/patch/20260422015026.7170-3-liubaolin12138@163.com/","project":{"id":8,"url":"http://patchwork.ozlabs.org/api/1.2/projects/8/?format=json","name":"Linux ext4 filesystem development","link_name":"linux-ext4","list_id":"linux-ext4.vger.kernel.org","list_email":"linux-ext4@vger.kernel.org","web_url":null,"scm_url":null,"webscm_url":null,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20260422015026.7170-3-liubaolin12138@163.com>","list_archive_url":null,"date":"2026-04-22T01:50:25","name":"[v3,v3,2/2] ext4: allow clearing mballoc stats through mb_stats","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"250b445500b60c49b7fa9ee36bdac8249aecab2f","submitter":{"id":89479,"url":"http://patchwork.ozlabs.org/api/1.2/people/89479/?format=json","name":"liubaolin","email":"liubaolin12138@163.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linux-ext4/patch/20260422015026.7170-3-liubaolin12138@163.com/mbox/","series":[{"id":500909,"url":"http://patchwork.ozlabs.org/api/1.2/series/500909/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-ext4/list/?series=500909","date":"2026-04-22T01:50:23","name":"add blocks_allocated to mb_stats and clear mb_stats","version":3,"mbox":"http://patchwork.ozlabs.org/series/500909/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2225998/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2225998/checks/","tags":{},"related":[],"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-ext4@vger.kernel.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","patchwork-incoming@ozlabs.org"],"Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=163.com header.i=@163.com header.a=rsa-sha256\n header.s=s110527 header.b=VqiApriF;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.org\n (client-ip=150.107.74.76; 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arc=none smtp.client-ip=220.197.31.5"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com;\n\ts=s110527; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=dE\n\tZ9FIUPUF+T6ETjcmLX+Rkx/mVcnjQZFx9WuuF6ilM=; b=VqiApriFvRN4Z6E9no\n\t7/+64z/mVsdsVapf9Ggzdz2vRtv3fAx+fhgHvdYgouQBq398YHi0asb6eX3Ah8Ar\n\tRovw21Cz7AiuPIyUc7rNq4hsD/B4sr2IoQvesU32H1oh21lrEuM8a1O534MLTGXI\n\tWGmCfvLfFgz8K6M47zBO/4mig=","From":"Baolin Liu ","To":"tytso@mit.edu,\n\tadilger.kernel@dilger.ca,\n\tojaswin@linux.ibm.com,\n\tritesh.list@gmail.com,\n\tyi.zhang@huawei.com","Cc":"linux-ext4@vger.kernel.org,\n\tlinux-kernel@vger.kernel.org,\n\twangguanyu@vivo.com,\n\tliubaolin12138@163.com,\n\tBaolin Liu ,\n\tAndreas Dilger ","Subject":"[PATCH v3 v3 2/2] ext4: allow clearing mballoc stats through mb_stats","Date":"Wed, 22 Apr 2026 09:50:25 +0800","Message-ID":"<20260422015026.7170-3-liubaolin12138@163.com>","X-Mailer":"git-send-email 2.51.0","In-Reply-To":"<20260422015026.7170-1-liubaolin12138@163.com>","References":"<20260422015026.7170-1-liubaolin12138@163.com>","Precedence":"bulk","X-Mailing-List":"linux-ext4@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","X-CM-TRANSID":"_____wA3Hx+uKehpOCzjAw--.387S4","X-Coremail-Antispam":"1Uf129KBjvJXoW3JrW8GFyxCr45CF1fGrW3Jrb_yoW7tFyUpF\n\ts8ZFyxGr18Wa47uws7Gr4xZw1Yy3W8Cw1UKryIv34rur9Iqr9YyF1rtryjyFyYgrWUAayk\n\tXF429ryUGr42ka7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2\n\t9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0z_73kDUUUUU=","X-CM-SenderInfo":"xolxutxrol0iasrtmqqrwthudrp/xtbCwgEP2WnoKcE7yQAA3O","X-Spam-Status":"No, score=-1.2 required=5.0 tests=ARC_SIGNED,ARC_VALID,\n\tDKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DMARC_PASS,\n\tFREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,\n\tMAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY\n\tautolearn=disabled version=4.0.1","X-Spam-Checker-Version":"SpamAssassin 4.0.1 (2024-03-25) on gandalf.ozlabs.org"},"content":"From: Baolin Liu \n\nMake /proc/fs/ext4//mb_stats writable and clear the runtime\nmballoc statistics when 0 is written.\nUpdate the related documentation accordingly.\n\nReviewed-by: Ojaswin Mujoo \nReviewed-by: Andreas Dilger \nReviewed-by: Ritesh Harjani (IBM) \nReviewed-by: Zhang Yi \nSigned-off-by: Baolin Liu \n---\n Documentation/admin-guide/ext4.rst | 5 ++++\n Documentation/filesystems/proc.rst | 3 +++\n fs/ext4/ext4.h | 1 +\n fs/ext4/mballoc.c | 29 ++++++++++++++++++++++\n fs/ext4/sysfs.c | 40 ++++++++++++++++++++++++++++--\n 5 files changed, 76 insertions(+), 2 deletions(-)","diff":"diff --git a/Documentation/admin-guide/ext4.rst b/Documentation/admin-guide/ext4.rst\nindex ac0c709ea9e7..fb3887cd5e44 100644\n--- a/Documentation/admin-guide/ext4.rst\n+++ b/Documentation/admin-guide/ext4.rst\n@@ -436,6 +436,11 @@ Files in /proc/fs/ext4/\n mb_groups\n details of multiblock allocator buddy cache of free blocks\n \n+ mb_stats\n+ reports runtime statistics from the multiblock allocator\n+ (mballoc). Writing 0 to this file clears the current\n+ statistics.\n+\n /sys entries\n ============\n \ndiff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst\nindex b0c0d1b45b99..7ce02573a3d9 100644\n--- a/Documentation/filesystems/proc.rst\n+++ b/Documentation/filesystems/proc.rst\n@@ -1634,6 +1634,9 @@ directory are shown in Table 1-12, below.\n ============== ==========================================================\n File Content\n mb_groups details of multiblock allocator buddy cache of free blocks\n+ mb_stats reports runtime statistics from the multiblock allocator\n+ (mballoc). Writing 0 to this file clears the current\n+ statistics.\n ============== ==========================================================\n \n 1.9 /proc/consoles\ndiff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h\nindex 293f698b7042..3223e73612ae 100644\n--- a/fs/ext4/ext4.h\n+++ b/fs/ext4/ext4.h\n@@ -2994,6 +2994,7 @@ int ext4_fc_record_regions(struct super_block *sb, int ino,\n extern const struct seq_operations ext4_mb_seq_groups_ops;\n extern const struct seq_operations ext4_mb_seq_structs_summary_ops;\n extern int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset);\n+extern void ext4_mb_stats_clear(struct ext4_sb_info *sbi);\n extern int ext4_mb_init(struct super_block *);\n extern void ext4_mb_release(struct super_block *);\n extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,\ndiff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c\nindex 1e13ef62cb9d..79ddfa935813 100644\n--- a/fs/ext4/mballoc.c\n+++ b/fs/ext4/mballoc.c\n@@ -4723,6 +4723,35 @@ static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)\n \t\ttrace_ext4_mballoc_prealloc(ac);\n }\n \n+void ext4_mb_stats_clear(struct ext4_sb_info *sbi)\n+{\n+\tint i;\n+\n+\tatomic_set(&sbi->s_bal_reqs, 0);\n+\tatomic_set(&sbi->s_bal_success, 0);\n+\tatomic_set(&sbi->s_bal_allocated, 0);\n+\tatomic_set(&sbi->s_bal_groups_scanned, 0);\n+\n+\tfor (i = 0; i < EXT4_MB_NUM_CRS; i++) {\n+\t\tatomic64_set(&sbi->s_bal_cX_hits[i], 0);\n+\t\tatomic64_set(&sbi->s_bal_cX_groups_considered[i], 0);\n+\t\tatomic_set(&sbi->s_bal_cX_ex_scanned[i], 0);\n+\t\tatomic64_set(&sbi->s_bal_cX_failed[i], 0);\n+\t}\n+\n+\tatomic_set(&sbi->s_bal_ex_scanned, 0);\n+\tatomic_set(&sbi->s_bal_goals, 0);\n+\tatomic_set(&sbi->s_bal_stream_goals, 0);\n+\tatomic_set(&sbi->s_bal_len_goals, 0);\n+\tatomic_set(&sbi->s_bal_2orders, 0);\n+\tatomic_set(&sbi->s_bal_breaks, 0);\n+\tatomic_set(&sbi->s_mb_lost_chunks, 0);\n+\tatomic_set(&sbi->s_mb_buddies_generated, 0);\n+\tatomic64_set(&sbi->s_mb_generation_time, 0);\n+\tatomic_set(&sbi->s_mb_preallocated, 0);\n+\tatomic_set(&sbi->s_mb_discarded, 0);\n+}\n+\n /*\n * Called on failure; free up any blocks from the inode PA for this\n * context. We don't need this for MB_GROUP_PA because we only change\ndiff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c\nindex b87d7bdab06a..e90885d470ab 100644\n--- a/fs/ext4/sysfs.c\n+++ b/fs/ext4/sysfs.c\n@@ -52,6 +52,42 @@ typedef enum {\n static const char proc_dirname[] = \"fs/ext4\";\n static struct proc_dir_entry *ext4_proc_root;\n \n+static int ext4_mb_stats_open(struct inode *inode, struct file *file)\n+{\n+\treturn single_open(file, ext4_seq_mb_stats_show, pde_data(inode));\n+}\n+\n+static ssize_t ext4_mb_stats_write(struct file *file, const char __user *buf,\n+\t\t\t\t\t size_t count, loff_t *ppos)\n+{\n+\tstruct super_block *sb = pde_data(file_inode(file));\n+\tchar kbuf[2];\n+\n+\tif (count == 0 || count > sizeof(kbuf))\n+\t\treturn -EINVAL;\n+\n+\tif (copy_from_user(kbuf, buf, count))\n+\t\treturn -EFAULT;\n+\n+\tif (count == 2) {\n+\t\tif (kbuf[0] != '0' || kbuf[1] != '\\n')\n+\t\t\treturn -EINVAL;\n+\t} else if (kbuf[0] != '0') {\n+\t\treturn -EINVAL;\n+\t}\n+\n+\text4_mb_stats_clear(EXT4_SB(sb));\n+\treturn count;\n+}\n+\n+static const struct proc_ops ext4_mb_stats_proc_ops = {\n+\t.proc_open\t= ext4_mb_stats_open,\n+\t.proc_read\t= seq_read,\n+\t.proc_lseek\t= seq_lseek,\n+\t.proc_release\t= single_release,\n+\t.proc_write\t= ext4_mb_stats_write,\n+};\n+\n struct ext4_attr {\n \tstruct attribute attr;\n \tshort attr_id;\n@@ -630,8 +666,8 @@ int ext4_register_sysfs(struct super_block *sb)\n \t\t\t\t\text4_fc_info_show, sb);\n \t\tproc_create_seq_data(\"mb_groups\", S_IRUGO, sbi->s_proc,\n \t\t\t\t&ext4_mb_seq_groups_ops, sb);\n-\t\tproc_create_single_data(\"mb_stats\", 0444, sbi->s_proc,\n-\t\t\t\text4_seq_mb_stats_show, sb);\n+\t\tproc_create_data(\"mb_stats\", 0644, sbi->s_proc,\n+\t\t\t\t &ext4_mb_stats_proc_ops, sb);\n \t\tproc_create_seq_data(\"mb_structs_summary\", 0444, sbi->s_proc,\n \t\t\t\t&ext4_mb_seq_structs_summary_ops, sb);\n \t}\n","prefixes":["v3","v3","2/2"]}