Re: [f2fs-dev] [PATCH V2] fsck.f2fs: allow fsck to fix issues with online resize due to SPO

[Sahitya Tummala <stummala@codeaurora.org>]

Hi Chao,

On Mon, Mar 16, 2020 at 11:19:11AM +0800, Chao Yu wrote:
> On 2020/3/6 11:52, Sahitya Tummala wrote:
> > Add support for new CP flag CP_RESIZEFS_FLAG set during online
> > resize FS. If SPO happens after SB is updated but CP isn't, then
> > allow fsck to fix it.
> > 
> > fsck errors without this fix -
> >     Info: CKPT version = 6ed7bccb
> >             Wrong user_block_count(2233856)
> >     [f2fs_do_mount:3365] Checkpoint is polluted
> > 
> > the subsequent mount failure without this fix -
> > [   11.294650] F2FS-fs (sda8): Wrong user_block_count: 2233856
> > [   11.300272] F2FS-fs (sda8): Failed to get valid F2FS checkpoint
> > 
> > Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
> > ---
> > v2:
> > - fix even if CP_FSCK_FLAG is set for backward compatibility
> > - update print_cp_state()
> > 
> >  fsck/mount.c      | 34 +++++++++++++++++++++++++++++++---
> >  include/f2fs_fs.h |  1 +
> >  2 files changed, 32 insertions(+), 3 deletions(-)
> > 
> > diff --git a/fsck/mount.c b/fsck/mount.c
> > index e4ba048..8d32e41 100644
> > --- a/fsck/mount.c
> > +++ b/fsck/mount.c
> > @@ -429,6 +429,8 @@ void print_cp_state(u32 flag)
> >  		MSG(0, "%s", " orphan_inodes");
> >  	if (flag & CP_DISABLED_FLAG)
> >  		MSG(0, "%s", " disabled");
> > +	if (flag & CP_RESIZEFS_FLAG)
> > +		MSG(0, "%s", " resizefs");
> >  	if (flag & CP_UMOUNT_FLAG)
> >  		MSG(0, "%s", " unmount");
> >  	else
> > @@ -1128,6 +1130,7 @@ int sanity_check_ckpt(struct f2fs_sb_info *sbi)
> >  	unsigned int total, fsmeta;
> >  	struct f2fs_super_block *sb = F2FS_RAW_SUPER(sbi);
> >  	struct f2fs_checkpoint *cp = F2FS_CKPT(sbi);
> > +	unsigned int flag = get_cp(ckpt_flags);
> >  	unsigned int ovp_segments, reserved_segments;
> >  	unsigned int main_segs, blocks_per_seg;
> >  	unsigned int sit_segs, nat_segs;
> > @@ -1164,7 +1167,32 @@ int sanity_check_ckpt(struct f2fs_sb_info *sbi)
> >  	log_blocks_per_seg = get_sb(log_blocks_per_seg);
> >  	if (!user_block_count || user_block_count >=
> >  			segment_count_main << log_blocks_per_seg) {
> > -		MSG(0, "\tWrong user_block_count(%u)\n", user_block_count);
> > +		if (flag & (CP_FSCK_FLAG | CP_RESIZEFS_FLAG)) {
> > +			u32 valid_user_block_cnt;
> > +			u32 seg_cnt_main = get_sb(segment_count) -
> > +					(get_sb(segment_count_ckpt) +
> > +					 get_sb(segment_count_sit) +
> > +					 get_sb(segment_count_nat) +
> > +					 get_sb(segment_count_ssa));
> > +
> > +			/* validate segment_count_main in sb first */
> > +			if (seg_cnt_main != get_sb(segment_count_main)) {
> > +				MSG(0, "\tWrong user_block_count(%u) and inconsistent segment_cnt_main %u\n",
> > +						user_block_count,
> > +						segment_count_main << log_blocks_per_seg);
> > +				return 1;
> > +			}
> > +			valid_user_block_cnt = ((get_sb(segment_count_main) -
> > +						get_cp(overprov_segment_count)) * c.blks_per_seg);
> > +			MSG(0, "\tInfo: Fix wrong user_block_count in CP: (%u) -> (%u)\n",
> > +					user_block_count, valid_user_block_cnt);
> 
> By default, we should only fix such bug if c.fix_on is true, something
> like this:
> 
> ASSERT_MSG("\tWrong user_block_count(%u)\n", user_block_count);
> 
> if (!c.fix_on)
> 	return 1;
> 
> valid_user_block_cnt = ((get_sb(segment_count_main) -
> 	get_cp(overprov_segment_count)) * c.blks_per_seg);
> 
> MSG(0, "\tInfo: Fix wrong user_block_count in CP: (%u) -> (%u)\n",
> 	user_block_count, valid_user_block_cnt);
> 
Since this is a fatal error which fails the basic mount itself, I thought it
must be fixed by default with fsck independent of -f option. Can we do so for
such critical bugs?

Thanks,

> Thanks,
> 
> 
> > +			set_cp(user_block_count, valid_user_block_cnt);
> > +			c.fix_on = 1;
> > +			c.bug_on = 1;
> > +		} else {
> > +			MSG(0, "\tWrong user_block_count(%u)\n", user_block_count);
> > +			return 1;
> > +		}
> >  		return 1;
> >  	}
> >  
> > @@ -3361,6 +3389,8 @@ int f2fs_do_mount(struct f2fs_sb_info *sbi)
> >  		return -1;
> >  	}
> >  
> > +	c.bug_on = 0;
> > +
> >  	if (sanity_check_ckpt(sbi)) {
> >  		ERR_MSG("Checkpoint is polluted\n");
> >  		return -1;
> > @@ -3380,8 +3410,6 @@ int f2fs_do_mount(struct f2fs_sb_info *sbi)
> >  			c.fix_on = 1;
> >  	}
> >  
> > -	c.bug_on = 0;
> > -
> >  	if (tune_sb_features(sbi))
> >  		return -1;
> >  
> > diff --git a/include/f2fs_fs.h b/include/f2fs_fs.h
> > index af31bc5..265f50c 100644
> > --- a/include/f2fs_fs.h
> > +++ b/include/f2fs_fs.h
> > @@ -678,6 +678,7 @@ struct f2fs_super_block {
> >  /*
> >   * For checkpoint
> >   */
> > +#define CP_RESIZEFS_FLAG                0x00004000
> >  #define CP_DISABLED_FLAG		0x00001000
> >  #define CP_QUOTA_NEED_FSCK_FLAG		0x00000800
> >  #define CP_LARGE_NAT_BITMAP_FLAG	0x00000400
> > 

-- 
--
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.


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