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

From: Jaegeuk Kim
Date: Sun Sep 30 2018 - 21:27:41 EST


On 10/01, Chao Yu wrote:
> On 2018-10-1 7:58, Jaegeuk Kim wrote:
> > 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.
>
> Oh, that's just warning, it could not be harmful, I think we can simply remove
> WARN_ON_ONCE in dquot_writeback_dquots to fix this?

Well, I think it'd be better to keep it.

>
> >
> >>
> >>> + }
> >>> 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.
>
> That's correct, IMO, the right way is that fsck needs to be aware of whole dnode
> chain and block address in dnode block, when doing allocation, it needs to
> bypass those block address of dnode and block which can be recovered later by
> kernel, so that fsynced data can not be lost.
>
> But, in order to trouble shoot current problem more quickly, we can just disable
> kernel recovery once fsck recovers quota file for now.
>
> Thanks,
>
> >
> >>
> >> 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);
> >>>
> >>>
> >
> >
> > _______________________________________________
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> >