Re: [f2fs-dev] [PATCH 2/2] fsck.f2fs: validate free seg count on zns device

[Aravind Ramesh <Aravind.Ramesh@wdc.com>]

> -----Original Message-----
> From: Jaegeuk Kim <jaegeuk@kernel.org>
> Sent: Tuesday, July 14, 2020 12:38 AM
> To: Aravind Ramesh <Aravind.Ramesh@wdc.com>
> Cc: yuchao0@huawei.com; linux-f2fs-devel@lists.sourceforge.net; Shinichiro
> Kawasaki <shinichiro.kawasaki@wdc.com>; Matias Bjorling
> <Matias.Bjorling@wdc.com>
> Subject: Re: [PATCH 2/2] fsck.f2fs: validate free seg count on zns device
> 
> Hi Aravind,
> 
> On 07/02, Aravind Ramesh wrote:
> > NVMe Zoned Namespace devices can have zone-capacity less than zone-size.
> > Zone-capacity indicates the number of usable blocks in a zone, if
> > zone-capacity is less than zone-size, then the segments which start
> > at/after zone-capacity are considered unusable. Only those segments
> > which start before the zone-capacity are considered as usable and
> > added to the free_segment_count and free_segment_bitmap of the kernel.
> >
> > Allow fsck to find the free_segment_count based on the zone-capacity
> > and compare with checkpoint values.
> >
> > Signed-off-by: Aravind Ramesh <aravind.ramesh@wdc.com>
> > Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
> > ---
> >  fsck/fsck.c  |  5 ++--
> >  fsck/fsck.h  |  2 ++
> >  fsck/mount.c | 75
> > ++++++++++++++++++++++++++++++++++++++++++++++++++--
> >  3 files changed, 78 insertions(+), 4 deletions(-)
> >
> > diff --git a/fsck/fsck.c b/fsck/fsck.c index e110f3d..ba2340d 100644
> > --- a/fsck/fsck.c
> > +++ b/fsck/fsck.c
> > @@ -1905,11 +1905,12 @@ int fsck_chk_meta(struct f2fs_sb_info *sbi)
> >  		if (IS_NODESEG(se->type))
> >  			sit_node_blks += se->valid_blocks;
> >  	}
> > -	if (fsck->chk.sit_free_segs + sit_valid_segs != TOTAL_SEGS(sbi)) {
> > +	if (fsck->chk.sit_free_segs + sit_valid_segs !=
> > +				get_usable_seg_count(sbi)) {
> >  		ASSERT_MSG("SIT usage does not match: sit_free_segs %u, "
> >  				"sit_valid_segs %u, total_segs %u",
> >  			fsck->chk.sit_free_segs, sit_valid_segs,
> > -			TOTAL_SEGS(sbi));
> > +			get_usable_seg_count(sbi));
> >  		return -EINVAL;
> >  	}
> >
> > diff --git a/fsck/fsck.h b/fsck/fsck.h index bc6a435..e86730c 100644
> > --- a/fsck/fsck.h
> > +++ b/fsck/fsck.h
> > @@ -224,6 +224,8 @@ extern u32 update_nat_bits_flags(struct
> f2fs_super_block *,
> >  				struct f2fs_checkpoint *, u32);
> >  extern void write_nat_bits(struct f2fs_sb_info *, struct f2fs_super_block *,
> >  			struct f2fs_checkpoint *, int);
> > +extern unsigned int get_usable_seg_count(struct f2fs_sb_info *);
> > +extern bool is_usable_seg(struct f2fs_sb_info *, unsigned int);
> >
> >  /* dump.c */
> >  struct dump_option {
> > diff --git a/fsck/mount.c b/fsck/mount.c index d0f2eab..72ca0cb 100644
> > --- a/fsck/mount.c
> > +++ b/fsck/mount.c
> > @@ -30,6 +30,76 @@
> >  #define ACL_OTHER		(0x20)
> >  #endif
> >
> > +static int get_device_idx(struct f2fs_sb_info *sbi, u_int32_t segno)
> > +{
> > +	block_t seg_start_blkaddr;
> > +	int i;
> > +
> > +	seg_start_blkaddr = SM_I(sbi)->main_blkaddr +
> > +				segno * DEFAULT_BLOCKS_PER_SEGMENT;
> > +	for (i = 0; i < c.ndevs; i++)
> > +		if (c.devices[i].start_blkaddr <= seg_start_blkaddr &&
> > +			c.devices[i].end_blkaddr > seg_start_blkaddr)
> > +			return i;
> > +	return 0;
> > +}
> > +
> > +#ifdef HAVE_LINUX_BLKZONED_H
> > +
> > +static int get_zone_idx_from_dev(struct f2fs_sb_info *sbi,
> > +					u_int32_t segno, u_int32_t dev_idx) {
> > +	block_t seg_start_blkaddr = START_BLOCK(sbi, segno);
> > +
> > +	return (seg_start_blkaddr - c.devices[dev_idx].start_blkaddr) >>
> > +			log_base_2(sbi->segs_per_sec * sbi->blocks_per_seg); }
> > +
> > +bool is_usable_seg(struct f2fs_sb_info *sbi, unsigned int segno) {
> > +	unsigned int secno = segno / sbi->segs_per_sec;
> > +	block_t seg_start = START_BLOCK(sbi, segno);
> > +	block_t blocks_per_sec = sbi->blocks_per_seg * sbi->segs_per_sec;
> > +	unsigned int dev_idx = get_device_idx(sbi, segno);
> > +	unsigned int zone_idx = get_zone_idx_from_dev(sbi, segno, dev_idx);
> > +	unsigned int sec_off = SM_I(sbi)->main_blkaddr >>
> > +						log_base_2(blocks_per_sec);
> > +
> > +	if (zone_idx < c.devices[dev_idx].nr_rnd_zones)
> > +		return true;
> > +
> > +	if (c.devices[dev_idx].zoned_model != F2FS_ZONED_HM)
> > +		return true;
> > +
> > +	return seg_start < ((sec_off + secno) * blocks_per_sec) +
> > +				c.devices[dev_idx].zone_cap_blocks[zone_idx];
> > +}
> > +
> > +unsigned int get_usable_seg_count(struct f2fs_sb_info *sbi) {
> > +	unsigned int i, usable_seg_count = 0;
> > +
> > +	for (i = 0; i < TOTAL_SEGS(sbi); i++)
> > +		if (is_usable_seg(sbi, i))
> > +			usable_seg_count++;
> > +
> > +	return usable_seg_count;
> > +}
> > +
> > +#else
> > +
> > +bool is_usable_seg(struct f2fs_sb_info *sbi, unsigned int segno)
> 
> I've applied the below small change to avoid Android build error.
> 
> --- a/fsck/mount.c
> +++ b/fsck/mount.c
> @@ -88,7 +88,7 @@ unsigned int get_usable_seg_count(struct f2fs_sb_info *sbi)
> 
>  #else
> 
> -bool is_usable_seg(struct f2fs_sb_info *sbi, unsigned int segno)
> +bool is_usable_seg(struct f2fs_sb_info *UNUSED(sbi), unsigned int
> +UNUSED(segno))
>  {
>         return true;
>  }
> 
> Thanks,

Ok. 

Thank you,
Aravind

> 
> > +{
> > +	return true;
> > +}
> > +
> > +unsigned int get_usable_seg_count(struct f2fs_sb_info *sbi) {
> > +	return TOTAL_SEGS(sbi);
> > +}
> > +
> > +#endif
> > +
> >  u32 get_free_segments(struct f2fs_sb_info *sbi)  {
> >  	u32 i, free_segs = 0;
> > @@ -37,7 +107,8 @@ u32 get_free_segments(struct f2fs_sb_info *sbi)
> >  	for (i = 0; i < TOTAL_SEGS(sbi); i++) {
> >  		struct seg_entry *se = get_seg_entry(sbi, i);
> >
> > -		if (se->valid_blocks == 0x0 && !IS_CUR_SEGNO(sbi, i))
> > +		if (se->valid_blocks == 0x0 && !IS_CUR_SEGNO(sbi, i) &&
> > +							is_usable_seg(sbi, i))
> >  			free_segs++;
> >  	}
> >  	return free_segs;
> > @@ -2337,7 +2408,7 @@ void build_sit_area_bitmap(struct f2fs_sb_info *sbi)
> >  		memcpy(ptr, se->cur_valid_map, SIT_VBLOCK_MAP_SIZE);
> >  		ptr += SIT_VBLOCK_MAP_SIZE;
> >
> > -		if (se->valid_blocks == 0x0) {
> > +		if (se->valid_blocks == 0x0 && is_usable_seg(sbi, segno)) {
> >  			if (le32_to_cpu(sbi->ckpt->cur_node_segno[0]) == segno
> ||
> >  				le32_to_cpu(sbi->ckpt->cur_data_segno[0]) ==
> segno ||
> >  				le32_to_cpu(sbi->ckpt->cur_node_segno[1]) ==
> segno ||
> > --
> > 2.19.1


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