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

[Sahitya Tummala <stummala@codeaurora.org>]

On Thu, Mar 19, 2020 at 06:47:07PM +0800, Chao Yu wrote:
> Hi Sahitya,
> 
> On 2020/3/19 17:15, Sahitya Tummala wrote:
> > 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?
> 
> I suggest to follow the options' meaning, e.g. if user specified --dry-run,
> however we change any bits on that image, it looks that break that option's
> semantics, and it may violate user's will.... so IMO, if user don't want to
> repair the image, it will be better to keep the image as it is.
> 
> Thoughts?

Sure Chao. I will update the patch to fix it as per your suggestion.

Thanks,
> 
> To Jaegeuk, thoughts?
> 
> Thanks,
> 
> > 
> > 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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