Re: [f2fs-dev] [PATCH] f2fs: fix quota info to adjust recovered data

[Jaegeuk Kim]

On 09/29, Chao Yu wrote:
> On 2018/9/29 7:40, Jaegeuk Kim wrote:
> > Testing other fix.
> > 
> > ---
> >  fs/f2fs/checkpoint.c |  7 +++++++
> >  fs/f2fs/f2fs.h       |  1 +
> >  fs/f2fs/gc.c         | 10 +++++++++-
> >  fs/f2fs/super.c      | 22 +++++++++++++++++++++-
> >  4 files changed, 38 insertions(+), 2 deletions(-)
> > 
> > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> > index 524b87667cf4..3fde91f41a91 100644
> > --- a/fs/f2fs/checkpoint.c
> > +++ b/fs/f2fs/checkpoint.c
> > @@ -1494,6 +1494,7 @@ int f2fs_write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
> >  {
> >  	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
> >  	unsigned long long ckpt_ver;
> > +	bool need_up = false;
> >  	int err = 0;
> >  
> >  	if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
> > @@ -1506,6 +1507,10 @@ int f2fs_write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
> >  		f2fs_msg(sbi->sb, KERN_WARNING,
> >  				"Start checkpoint disabled!");
> >  	}
> > +	if (!is_sbi_flag_set(sbi, SBI_QUOTA_INIT)) {
> > +		need_up = true;
> > +		down_read(&sbi->sb->s_umount);
> 
> This is to avoid show warning when calling dquot_writeback_dquots() in
> f2fs_quota_sync(), right?

Yup. Unfortunately, this can't fix all the issues, so I'm testing trylock
simply in this case.

> 
> > +	}
> >  	mutex_lock(&sbi->cp_mutex);
> >  
> >  	if (!is_sbi_flag_set(sbi, SBI_IS_DIRTY) &&
> > @@ -1582,6 +1587,8 @@ int f2fs_write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
> >  	trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, "finish checkpoint");
> >  out:
> >  	mutex_unlock(&sbi->cp_mutex);
> > +	if (need_up)
> > +		up_read(&sbi->sb->s_umount);
> >  	return err;
> >  }
> >  
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index 57c829dd107e..30194f2f108e 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -1096,6 +1096,7 @@ enum {
> >  	SBI_IS_SHUTDOWN,			/* shutdown by ioctl */
> >  	SBI_IS_RECOVERED,			/* recovered orphan/data */
> >  	SBI_CP_DISABLED,			/* CP was disabled last mount */
> > +	SBI_QUOTA_INIT,				/* avoid sb->s_umount lock */
> >  	SBI_QUOTA_NEED_FLUSH,			/* need to flush quota info in CP */
> >  	SBI_QUOTA_SKIP_FLUSH,			/* skip flushing quota in current CP */
> >  	SBI_QUOTA_NEED_REPAIR,			/* quota file may be corrupted */
> > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> > index adaf5a695b12..deece448cb3b 100644
> > --- a/fs/f2fs/gc.c
> > +++ b/fs/f2fs/gc.c
> > @@ -55,9 +55,14 @@ static int gc_thread_func(void *data)
> >  			f2fs_stop_checkpoint(sbi, false);
> >  		}
> >  
> > -		if (!sb_start_write_trylock(sbi->sb))
> > +		if (!down_read_trylock(&sbi->sb->s_umount))
> >  			continue;
> >  
> > +		set_sbi_flag(sbi, SBI_QUOTA_INIT);
> > +
> > +		if (!sb_start_write_trylock(sbi->sb))
> > +			goto next_umount;
> > +
> >  		/*
> >  		 * [GC triggering condition]
> >  		 * 0. GC is not conducted currently.
> > @@ -104,6 +109,9 @@ static int gc_thread_func(void *data)
> >  		f2fs_balance_fs_bg(sbi);
> >  next:
> >  		sb_end_write(sbi->sb);
> > +next_umount:
> > +		clear_sbi_flag(sbi, SBI_QUOTA_INIT);
> > +		up_read(&sbi->sb->s_umount);
> >  
> >  	} while (!kthread_should_stop());
> >  	return 0;
> > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > index a28c245b1288..40a77a4eb465 100644
> > --- a/fs/f2fs/super.c
> > +++ b/fs/f2fs/super.c
> > @@ -1029,6 +1029,8 @@ static void f2fs_put_super(struct super_block *sb)
> >  	int i;
> >  	bool dropped;
> >  
> > +	set_sbi_flag(sbi, SBI_QUOTA_INIT);
> > +
> >  	f2fs_quota_off_umount(sb);
> >  
> >  	/* prevent remaining shrinker jobs */
> > @@ -1122,11 +1124,17 @@ int f2fs_sync_fs(struct super_block *sb, int sync)
> >  
> >  	if (sync) {
> >  		struct cp_control cpc;
> > +		bool keep = is_sbi_flag_set(sbi, SBI_QUOTA_INIT);
> >  
> >  		cpc.reason = __get_cp_reason(sbi);
> >  
> >  		mutex_lock(&sbi->gc_mutex);
> > +		if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE)
> > +			set_sbi_flag(sbi, SBI_QUOTA_INIT);
> > +
> >  		err = f2fs_write_checkpoint(sbi, &cpc);
> > +		if (!keep)
> > +			clear_sbi_flag(sbi, SBI_QUOTA_INIT);
> >  		mutex_unlock(&sbi->gc_mutex);
> >  	}
> >  	f2fs_trace_ios(NULL, 1);
> > @@ -1534,6 +1542,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
> >  		}
> >  	}
> >  #endif
> > +	set_sbi_flag(sbi, SBI_QUOTA_INIT);
> >  
> >  	/* recover superblocks we couldn't write due to previous RO mount */
> >  	if (!(*flags & SB_RDONLY) && is_sbi_flag_set(sbi, SBI_NEED_SB_WRITE)) {
> > @@ -1653,6 +1662,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
> >  		(test_opt(sbi, POSIX_ACL) ? SB_POSIXACL : 0);
> >  
> >  	limit_reserve_root(sbi);
> > +	clear_sbi_flag(sbi, SBI_QUOTA_INIT);
> >  	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
> >  	return 0;
> >  restore_gc:
> > @@ -1673,6 +1683,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
> >  #endif
> >  	sbi->mount_opt = org_mount_opt;
> >  	sb->s_flags = old_sb_flags;
> > +	clear_sbi_flag(sbi, SBI_QUOTA_INIT);
> >  	return err;
> >  }
> >  
> > @@ -1706,6 +1717,7 @@ static ssize_t f2fs_quota_read(struct super_block *sb, int type, char *data,
> >  				congestion_wait(BLK_RW_ASYNC, HZ/50);
> >  				goto repeat;
> >  			}
> > +			set_sbi_flag(F2FS_SB(sb), SBI_QUOTA_NEED_REPAIR);
> >  			return PTR_ERR(page);
> >  		}
> >  
> > @@ -1717,6 +1729,7 @@ static ssize_t f2fs_quota_read(struct super_block *sb, int type, char *data,
> >  		}
> >  		if (unlikely(!PageUptodate(page))) {
> >  			f2fs_put_page(page, 1);
> > +			set_sbi_flag(F2FS_SB(sb), SBI_QUOTA_NEED_REPAIR);
> >  			return -EIO;
> >  		}
> >  
> > @@ -1758,6 +1771,7 @@ static ssize_t f2fs_quota_write(struct super_block *sb, int type,
> >  				congestion_wait(BLK_RW_ASYNC, HZ/50);
> >  				goto retry;
> >  			}
> > +			set_sbi_flag(F2FS_SB(sb), SBI_QUOTA_NEED_REPAIR);
> >  			break;
> 
> I added these before, but later I didn't encounter quota corruption w/o
> them, so I removed them.
> 
> Do you still hit corruption after this change?

I found one issue where we must avoid roll-forward recovery, if fsck overwrote some
blocks to fix quota which will be used for recovery.

> 
> Thanks,
> 
> >  		}
> >  
> > @@ -1794,7 +1808,6 @@ static qsize_t *f2fs_get_reserved_space(struct inode *inode)
> >  
> >  static int f2fs_quota_on_mount(struct f2fs_sb_info *sbi, int type)
> >  {
> > -
> >  	if (is_set_ckpt_flags(sbi, CP_QUOTA_NEED_FSCK_FLAG)) {
> >  		f2fs_msg(sbi->sb, KERN_ERR,
> >  			"quota sysfile may be corrupted, skip loading it");
> > @@ -1958,7 +1971,9 @@ static int f2fs_quota_on(struct super_block *sb, int type, int format_id,
> >  	if (err)
> >  		return err;
> >  
> > +	set_sbi_flag(F2FS_SB(sb), SBI_QUOTA_INIT);
> >  	err = dquot_quota_on(sb, type, format_id, path);
> > +	clear_sbi_flag(F2FS_SB(sb), SBI_QUOTA_INIT);
> >  	if (err)
> >  		return err;
> >  
> > @@ -3179,6 +3194,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> >  		goto free_meta_inode;
> >  	}
> >  
> > +	set_sbi_flag(sbi, SBI_QUOTA_INIT);
> >  	if (__is_set_ckpt_flags(F2FS_CKPT(sbi), CP_QUOTA_NEED_FSCK_FLAG))
> >  		set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR);
> >  
> > @@ -3370,6 +3386,8 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> >  				cur_cp_version(F2FS_CKPT(sbi)));
> >  	f2fs_update_time(sbi, CP_TIME);
> >  	f2fs_update_time(sbi, REQ_TIME);
> > +
> > +	clear_sbi_flag(sbi, SBI_QUOTA_INIT);
> >  	return 0;
> >  
> >  free_meta:
> > @@ -3434,6 +3452,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> >  		shrink_dcache_sb(sb);
> >  		goto try_onemore;
> >  	}
> > +	clear_sbi_flag(sbi, SBI_QUOTA_INIT);
> >  	return err;
> >  }
> >  
> > @@ -3449,6 +3468,7 @@ static void kill_f2fs_super(struct super_block *sb)
> >  		struct f2fs_sb_info *sbi = F2FS_SB(sb);
> >  
> >  		set_sbi_flag(sbi, SBI_IS_CLOSE);
> > +		set_sbi_flag(sbi, SBI_QUOTA_INIT);
> >  		f2fs_stop_gc_thread(sbi);
> >  		f2fs_stop_discard_thread(sbi);
> >  
> >