[PATCH] f2fs: no need to flush NAT bits if no enough space

[PATCH] f2fs: no need to flush NAT bits if no enough space

[Weichao Guo]

NAT bits are saved at spare space in CP pack. Flushed NAT bits
may be overwritten by the CP pack if there is no enough space
for NAT bits. And NAT bits will be obsolesced at next mount time
if crc|cp_ver not matched. So just skip to flush NAT bits in such
needless cases.

Signed-off-by: Weichao Guo <guoweichao@huawei.com>
---
 fs/f2fs/checkpoint.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 0eaafb8..bdc03c9 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1248,7 +1248,9 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	start_blk = __start_cp_next_addr(sbi);
 
 	/* write nat bits */
-	if (enabled_nat_bits(sbi, cpc)) {
+	if (enabled_nat_bits(sbi, cpc) &&
+			le32_to_cpu(ckpt->cp_pack_total_block_count) <=
+			sbi->blocks_per_seg - NM_I(sbi)->nat_bits_blocks) {
 		__u64 cp_ver = cur_cp_version(ckpt);
 		block_t blk;
 
-- 
2.10.1


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Re: [PATCH] f2fs: no need to flush NAT bits if no enough space

[guoweichao]

On 2018/2/5 22:30, Weichao Guo wrote:
> NAT bits are saved at spare space in CP pack. Flushed NAT bits
> may be overwritten by the CP pack if there is no enough space
> for NAT bits. And NAT bits will be obsolesced at next mount time
Sorry, there is a typo here. 'obsolesced' should be obsolete.

Thanks,

> if crc|cp_ver not matched. So just skip to flush NAT bits in such
> needless cases.
> 
> Signed-off-by: Weichao Guo <guoweichao@huawei.com>
> ---
>  fs/f2fs/checkpoint.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> index 0eaafb8..bdc03c9 100644
> --- a/fs/f2fs/checkpoint.c
> +++ b/fs/f2fs/checkpoint.c
> @@ -1248,7 +1248,9 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
>  	start_blk = __start_cp_next_addr(sbi);
>  
>  	/* write nat bits */
> -	if (enabled_nat_bits(sbi, cpc)) {
> +	if (enabled_nat_bits(sbi, cpc) &&
> +			le32_to_cpu(ckpt->cp_pack_total_block_count) <=
> +			sbi->blocks_per_seg - NM_I(sbi)->nat_bits_blocks) {
>  		__u64 cp_ver = cur_cp_version(ckpt);
>  		block_t blk;
>  
> 


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Re: [PATCH] f2fs: no need to flush NAT bits if no enough space

[Chao Yu]

On 2018/2/5 22:30, Weichao Guo wrote:
> NAT bits are saved at spare space in CP pack. Flushed NAT bits
> may be overwritten by the CP pack if there is no enough space
> for NAT bits. And NAT bits will be obsolesced at next mount time
> if crc|cp_ver not matched. So just skip to flush NAT bits in such
> needless cases.
> 
> Signed-off-by: Weichao Guo <guoweichao@huawei.com>
> ---
>  fs/f2fs/checkpoint.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> index 0eaafb8..bdc03c9 100644
> --- a/fs/f2fs/checkpoint.c
> +++ b/fs/f2fs/checkpoint.c
> @@ -1248,7 +1248,9 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
>  	start_blk = __start_cp_next_addr(sbi);
>  
>  	/* write nat bits */
> -	if (enabled_nat_bits(sbi, cpc)) {
> +	if (enabled_nat_bits(sbi, cpc) &&
> +			le32_to_cpu(ckpt->cp_pack_total_block_count) <=
> +			sbi->blocks_per_seg - NM_I(sbi)->nat_bits_blocks) {

Have checked this condition in update_ckpt_flags, right?

thanks,

>  		__u64 cp_ver = cur_cp_version(ckpt);
>  		block_t blk;
>  
> 


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Re: [PATCH] f2fs: no need to flush NAT bits if no enough space

[guoweichao]

On 2018/2/5 15:42, Chao Yu wrote:
> On 2018/2/5 22:30, Weichao Guo wrote:
>> NAT bits are saved at spare space in CP pack. Flushed NAT bits
>> may be overwritten by the CP pack if there is no enough space
>> for NAT bits. And NAT bits will be obsolesced at next mount time
>> if crc|cp_ver not matched. So just skip to flush NAT bits in such
>> needless cases.
>>
>> Signed-off-by: Weichao Guo <guoweichao@huawei.com>
>> ---
>>  fs/f2fs/checkpoint.c | 4 +++-
>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
>> index 0eaafb8..bdc03c9 100644
>> --- a/fs/f2fs/checkpoint.c
>> +++ b/fs/f2fs/checkpoint.c
>> @@ -1248,7 +1248,9 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
>>  	start_blk = __start_cp_next_addr(sbi);
>>  
>>  	/* write nat bits */
>> -	if (enabled_nat_bits(sbi, cpc)) {
>> +	if (enabled_nat_bits(sbi, cpc) &&
>> +			le32_to_cpu(ckpt->cp_pack_total_block_count) <=
>> +			sbi->blocks_per_seg - NM_I(sbi)->nat_bits_blocks) {
> 
> Have checked this condition in update_ckpt_flags, right?
Oh,yes. It's my mistake.

Thanks,
> 
> thanks,
> 
>>  		__u64 cp_ver = cur_cp_version(ckpt);
>>  		block_t blk;
>>  
>>
> 
> 
> .
> 


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