From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932660AbdJYKGj (ORCPT ); Wed, 25 Oct 2017 06:06:39 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:9498 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932630AbdJYKGc (ORCPT ); Wed, 25 Oct 2017 06:06:32 -0400 Subject: Re: [PATCH v2] f2fs: introduce cur_reserved_blocks in sysfs From: Yunlong Song To: Chao Yu , , , CC: , , , , References: <1502199825-15218-1-git-send-email-yunlong.song@huawei.com> <1502451826-45453-1-git-send-email-yunlong.song@huawei.com> <2e1652f9-5e3a-4f38-5736-54b1a89ac02a@huawei.com> <3ef856f1-4155-4821-4cf8-25f5872257e5@huawei.com> Message-ID: <617468f3-2723-d3d3-d23f-da8aa488862b@huawei.com> Date: Wed, 25 Oct 2017 18:02:20 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [10.111.220.140] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A010202.59F0615D.002E,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 96b9d0bfd27b6a6fc7cfea6ba380a7a9 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Chao, ping... Please see the review comment below. And the change is already in the v3 patch. On 2017/8/18 23:16, Yunlong Song wrote: > I send a v3 patch, please review, and the main difference is shown below. > > On 2017/8/18 18:20, Chao Yu wrote: >> Hi Yunlong, >> >> IMO, we don't need additional sysfs entry, how about changing a bit >> as below? >> >> >From 3fc8206871fe457859f1537c9dc8918b45f14601 Mon Sep 17 00:00:00 2001 >> From: Yunlong Song >> Date: Wed, 16 Aug 2017 23:01:56 +0800 >> Subject: [PATCH] f2fs: support soft block reservation >> >> It supports to extend reserved_blocks sysfs interface to be soft >> threshold, which allows user configure it exceeding current available >> user space. >> >> Signed-off-by: Yunlong Song >> Signed-off-by: Chao Yu >> --- >> Documentation/ABI/testing/sysfs-fs-f2fs | 3 ++- >> fs/f2fs/f2fs.h | 12 ++++++++++-- >> fs/f2fs/super.c | 3 ++- >> fs/f2fs/sysfs.c | 16 ++++++++++++++-- >> 4 files changed, 28 insertions(+), 6 deletions(-) >> >> diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs >> b/Documentation/ABI/testing/sysfs-fs-f2fs >> index 11b7f4ebea7c..45c3d92f77c8 100644 >> --- a/Documentation/ABI/testing/sysfs-fs-f2fs >> +++ b/Documentation/ABI/testing/sysfs-fs-f2fs >> @@ -138,7 +138,8 @@ What: /sys/fs/f2fs//reserved_blocks >> Date: June 2017 >> Contact: "Chao Yu" >> Description: >> - Controls current reserved blocks in system. >> + Controls current reserved blocks in system, the threshold >> + is soft, it could exceed current avaible user space. >> >> What: /sys/fs/f2fs//gc_urgent >> Date: August 2017 >> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h >> index 336021b9b93e..a7b2d257e8ee 100644 >> --- a/fs/f2fs/f2fs.h >> +++ b/fs/f2fs/f2fs.h >> @@ -1046,6 +1046,7 @@ struct f2fs_sb_info { >> block_t discard_blks; /* discard command candidats */ >> block_t last_valid_block_count; /* for recovery */ >> block_t reserved_blocks; /* configurable reserved blocks */ >> + block_t current_reserved_blocks; /* current reserved blocks */ >> >> u32 s_next_generation; /* for NFS support */ >> >> @@ -1520,7 +1521,8 @@ static inline int inc_valid_block_count(struct >> f2fs_sb_info *sbi, >> >> spin_lock(&sbi->stat_lock); >> sbi->total_valid_block_count += (block_t)(*count); >> - avail_user_block_count = sbi->user_block_count - >> sbi->reserved_blocks; >> + avail_user_block_count = sbi->user_block_count - >> + sbi->current_reserved_blocks; >> if (unlikely(sbi->total_valid_block_count > >> avail_user_block_count)) { >> diff = sbi->total_valid_block_count - avail_user_block_count; >> *count -= diff; >> @@ -1554,6 +1556,9 @@ static inline void dec_valid_block_count(struct >> f2fs_sb_info *sbi, >> f2fs_bug_on(sbi, sbi->total_valid_block_count < (block_t) count); >> f2fs_bug_on(sbi, inode->i_blocks < sectors); >> sbi->total_valid_block_count -= (block_t)count; >> + if (sbi->reserved_blocks) > Add sbi->reserved_blocks != sbi->cur_reserved_blocks check >> + sbi->current_reserved_blocks = min(sbi->reserved_blocks, >> + sbi->current_reserved_blocks + count); >> spin_unlock(&sbi->stat_lock); >> f2fs_i_blocks_write(inode, count, false, true); >> } >> @@ -1700,7 +1705,7 @@ static inline int inc_valid_node_count(struct >> f2fs_sb_info *sbi, >> spin_lock(&sbi->stat_lock); >> >> valid_block_count = sbi->total_valid_block_count + 1; >> - if (unlikely(valid_block_count + sbi->reserved_blocks > >> + if (unlikely(valid_block_count + sbi->current_reserved_blocks > >> sbi->user_block_count)) { >> spin_unlock(&sbi->stat_lock); >> goto enospc; >> @@ -1743,6 +1748,9 @@ static inline void dec_valid_node_count(struct >> f2fs_sb_info *sbi, >> >> sbi->total_valid_node_count--; >> sbi->total_valid_block_count--; >> + if (sbi->reserved_blocks) >> + sbi->current_reserved_blocks = min(sbi->reserved_blocks, >> + sbi->current_reserved_blocks + 1); > change to sbi->cur_reserved_blocks++; >> >> spin_unlock(&sbi->stat_lock); >> >> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c >> index 4c1bdcb94133..036f083bbf56 100644 >> --- a/fs/f2fs/super.c >> +++ b/fs/f2fs/super.c >> @@ -957,7 +957,7 @@ static int f2fs_statfs(struct dentry *dentry, >> struct kstatfs *buf) >> buf->f_blocks = total_count - start_count; >> buf->f_bfree = user_block_count - valid_user_blocks(sbi) + >> ovp_count; >> buf->f_bavail = user_block_count - valid_user_blocks(sbi) - >> - sbi->reserved_blocks; >> + sbi->current_reserved_blocks; >> >> avail_node_count = sbi->total_node_count - F2FS_RESERVED_NODE_NUM; >> >> @@ -2411,6 +2411,7 @@ static int f2fs_fill_super(struct super_block >> *sb, void *data, int silent) >> le64_to_cpu(sbi->ckpt->valid_block_count); >> sbi->last_valid_block_count = sbi->total_valid_block_count; >> sbi->reserved_blocks = 0; >> + sbi->current_reserved_blocks = 0; >> >> for (i = 0; i < NR_INODE_TYPE; i++) { >> INIT_LIST_HEAD(&sbi->inode_list[i]); >> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c >> index 4bcaa9059026..3173a272fe7c 100644 >> --- a/fs/f2fs/sysfs.c >> +++ b/fs/f2fs/sysfs.c >> @@ -104,12 +104,23 @@ static ssize_t features_show(struct f2fs_attr *a, >> return len; >> } >> >> +static ssize_t f2fs_reserved_blocks_show(struct f2fs_attr *a, >> + struct f2fs_sb_info *sbi, char *buf) >> +{ >> + return snprintf(buf, PAGE_SIZE, >> + "expected: %u\ncurrent: %u\n", >> + sbi->reserved_blocks, sbi->current_reserved_blocks); >> +} >> + >> static ssize_t f2fs_sbi_show(struct f2fs_attr *a, >> struct f2fs_sb_info *sbi, char *buf) >> { >> unsigned char *ptr = NULL; >> unsigned int *ui; >> >> + if (a->struct_type == RESERVED_BLOCKS) >> + return f2fs_reserved_blocks_show(a, sbi, buf); >> + >> ptr = __struct_ptr(sbi, a->struct_type); >> if (!ptr) >> return -EINVAL; >> @@ -143,12 +154,13 @@ static ssize_t f2fs_sbi_store(struct f2fs_attr *a, >> #endif >> if (a->struct_type == RESERVED_BLOCKS) { >> spin_lock(&sbi->stat_lock); >> - if ((unsigned long)sbi->total_valid_block_count + t > >> - (unsigned long)sbi->user_block_count) { >> + if (t > (unsigned long)sbi->user_block_count) { >> spin_unlock(&sbi->stat_lock); >> return -EINVAL; >> } >> *ui = t; >> + sbi->current_reserved_blocks = min(sbi->reserved_blocks, >> + sbi->user_block_count - valid_user_blocks(sbi)); > This is not safe for support system's activation, since the user > available space can be suddenly zero! > So I change this to only admit t < sbi->cur_reserved_blocks then > change its value. >> spin_unlock(&sbi->stat_lock); >> return count; >> } > -- Thanks, Yunlong Song