Hi Xiang Gao,
On 2018/1/13 19:16, Gao Xiang wrote:
> Hi Chao,
>
>
> On 2018/01/12 18:24, Chao Yu wrote:
>
>> Previously, our total node number (nat_bitmap) and total nat segment count
>> will not monotonously increase along with image size, and max nat_bitmap size
>> is limited by "CHECKSUM_OFFSET - sizeof(struct f2fs_checkpoint) + 1", it is
>> with bad scalability when user wants to create more inode/node in larger
>> image.
>>
>> So this patch tries to relieve the limitation, by default, limitting total
>> nat
>> entry number with 20% of total block number.
>>
>> Before:
>> image_size(GB) nat_bitmap sit_bitmap nat_segment
>> sit_segment
>> 16 3836 64 36 2
>> 32 3836 64 72 2
>> 64 3772 128 116 4
>> 128 3708 192 114 6
>> 256 3580 320 110 10
>> 512 3260 640 100 20
>> 1024 2684 1216 82 38
>> 2048 1468 2432 44 76
>> 4096 3900 4800 120 150
>>
>> After:
>> image_size(GB) nat_bitmap sit_bitmap nat_segment
>> sit_segment
>> 16 256 64 8 2
>> 32 512 64 16 2
>> 64 960 128 30 4
>> 128 1856 192 58 6
>> 256 3712 320 116 10
>> 512 7424 640 232 20
>> 1024 14787 1216 462 38
>> 2048 29504 2432 922 76
>> 4096 59008 4800 1844 150
>>
>> Signed-off-by: Chao Yu <yuchao0@...>
>> ---
>> fsck/resize.c | 31 ++++++++++++++-----------------
>> include/f2fs_fs.h | 6 ++++--
>> mkfs/f2fs_format.c | 35 ++++++++++++++---------------------
>> 3 files changed, 32 insertions(+), 40 deletions(-)
>>
>> diff --git a/fsck/resize.c b/fsck/resize.c
>> index 143ad5d3c0a1..7613c7df4893 100644
>> --- a/fsck/resize.c
>> +++ b/fsck/resize.c
>> @@ -16,7 +16,7 @@ static int get_new_sb(struct f2fs_super_block *sb)
>> u_int32_t sit_segments, diff, total_meta_segments;
>> u_int32_t total_valid_blks_available;
>> u_int32_t sit_bitmap_size, max_sit_bitmap_size;
>> - u_int32_t max_nat_bitmap_size, max_nat_segments;
>> + u_int32_t max_nat_bitmap_size;
>> u_int32_t segment_size_bytes = 1 << (get_sb(log_blocksize) +
>> get_sb(log_blocks_per_seg));
>> u_int32_t blks_per_seg = 1 << get_sb(log_blocks_per_seg);
>> @@ -47,7 +47,8 @@ static int get_new_sb(struct f2fs_super_block *sb)
>> get_sb(segment_count_sit))) * blks_per_seg;
>> blocks_for_nat = SIZE_ALIGN(total_valid_blks_available,
>> NAT_ENTRY_PER_BLOCK);
>> - set_sb(segment_count_nat, SEG_ALIGN(blocks_for_nat));
>> + set_sb(segment_count_nat, SEG_ALIGN(blocks_for_nat) *
>> + DEFAULT_NAT_ENTRY_RATIO / 100);
>>
>> sit_bitmap_size = ((get_sb(segment_count_sit) / 2) <<
>> get_sb(log_blocks_per_seg)) / 8;
>> @@ -56,25 +57,21 @@ static int get_new_sb(struct f2fs_super_block *sb)
>> else
>> max_sit_bitmap_size = sit_bitmap_size;
>>
>> - /*
>> - * It should be reserved minimum 1 segment for nat.
>> - * When sit is too large, we should expand cp area. It requires more
>> pages for cp.
>> - */
>> - if (max_sit_bitmap_size > MAX_SIT_BITMAP_SIZE_IN_CKPT) {
>> - max_nat_bitmap_size = CHECKSUM_OFFSET - sizeof(struct
>> f2fs_checkpoint) + 1;
>> - set_sb(cp_payload, F2FS_BLK_ALIGN(max_sit_bitmap_size));
>> + max_nat_bitmap_size = (get_sb(segment_count_nat) <<
>> + get_sb(log_blocks_per_seg)) / 8;
> segment_count_nat would not exceed (CHECKSUM_OFFSET - sizeof(struct
> f2fs_checkpoint) + 1) * 8 >> get_sb(log_blocks_per_seg) (align-down), I
> think.
> In my mind, the nat version bitmap is only located in cp page...
> So segment_count_nat has a fixed up bound limitation...
If we want to support large nid bitmap, we need to break this rule, as
nat_bitmap size may exceed "CHECKSUM_OFFSET - sizeof(struct
f2fs_checkpoint) + 1".
>
>> +
>> + set_sb(segment_count_nat, get_sb(segment_count_nat) * 2);
>> +
>> + /* use cp_payload if free space of f2fs_checkpoint is not enough */
>> + if (max_sit_bitmap_size + max_nat_bitmap_size >
>> + MAX_BITMAP_SIZE_IN_CKPT) {
>> + u_int32_t diff = max_sit_bitmap_size + max_nat_bitmap_size -
>> + MAX_BITMAP_SIZE_IN_CKPT;
> I looked up the f2fs source code, in __bitmap_ptr
>
> if payload is used, the whole payload will be used for sit bitmap.
Oh, I missed to change it. Please check v2.
Thanks,
>
> Therefore, I mean would it be u_int32_t diff = max_sit_bitmap_size?
>
> or modify definition in f2fs.h?
>
>> + set_sb(cp_payload, F2FS_BLK_ALIGN(diff));
>> } else {
>> - max_nat_bitmap_size = CHECKSUM_OFFSET - sizeof(struct
>> f2fs_checkpoint) + 1
>> - - max_sit_bitmap_size;
>> set_sb(cp_payload, 0);
>> }
>>
>> - max_nat_segments = (max_nat_bitmap_size * 8) >>
>> - get_sb(log_blocks_per_seg);
>> -
>> - if (get_sb(segment_count_nat) > max_nat_segments)
>> - set_sb(segment_count_nat, max_nat_segments);
>> -
>> set_sb(segment_count_nat, get_sb(segment_count_nat) * 2);
>>
>> set_sb(ssa_blkaddr, get_sb(nat_blkaddr) +
>> diff --git a/include/f2fs_fs.h b/include/f2fs_fs.h
>> index 4739085ed98f..77e53dfea474 100644
>> --- a/include/f2fs_fs.h
>> +++ b/include/f2fs_fs.h
>> @@ -657,8 +657,8 @@ struct f2fs_checkpoint {
>> unsigned char sit_nat_version_bitmap[1];
>> } __attribute__((packed));
>>
>> -#define MAX_SIT_BITMAP_SIZE_IN_CKPT \
>> - (CHECKSUM_OFFSET - sizeof(struct f2fs_checkpoint) + 1 - 64)
>> +#define MAX_BITMAP_SIZE_IN_CKPT \
>> + (CHECKSUM_OFFSET - sizeof(struct f2fs_checkpoint) + 1)
>>
>> /*
>> * For orphan inode management
>> @@ -846,6 +846,8 @@ struct f2fs_node {
>> #define NAT_ENTRY_PER_BLOCK (PAGE_CACHE_SIZE / sizeof(struct
>> f2fs_nat_entry))
>> #define NAT_BLOCK_OFFSET(start_nid) (start_nid / NAT_ENTRY_PER_BLOCK)
>>
>> +#define DEFAULT_NAT_ENTRY_RATIO 20
>> +
>> #ifdef ANDROID_WINDOWS_HOST
>> #pragma pack(1)
>> #endif
>> diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
>> index a13000184300..90363370031e 100644
>> --- a/mkfs/f2fs_format.c
>> +++ b/mkfs/f2fs_format.c
>> @@ -157,7 +157,7 @@ static int f2fs_prepare_super_block(void)
>> u_int64_t zone_align_start_offset, diff;
>> u_int64_t total_meta_zones, total_meta_segments;
>> u_int32_t sit_bitmap_size, max_sit_bitmap_size;
>> - u_int32_t max_nat_bitmap_size, max_nat_segments;
>> + u_int32_t max_nat_bitmap_size;
>> u_int32_t total_zones;
>> u_int32_t next_ino;
>> enum quota_type qtype;
>> @@ -272,7 +272,8 @@ static int f2fs_prepare_super_block(void)
>> blocks_for_nat = SIZE_ALIGN(total_valid_blks_available,
>> NAT_ENTRY_PER_BLOCK);
>>
>> - set_sb(segment_count_nat, SEG_ALIGN(blocks_for_nat));
>> + set_sb(segment_count_nat, SEG_ALIGN(blocks_for_nat) *
>> + DEFAULT_NAT_ENTRY_RATIO / 100);
>> /*
>> * The number of node segments should not be exceeded a "Threshold".
>> * This number resizes NAT bitmap area in a CP page.
>> @@ -286,29 +287,21 @@ static int f2fs_prepare_super_block(void)
>> else
>> max_sit_bitmap_size = sit_bitmap_size;
>>
>> - /*
>> - * It should be reserved minimum 1 segment for nat.
>> - * When sit is too large, we should expand cp area. It requires more
>> - * pages for cp.
>> - */
>> - if (max_sit_bitmap_size > MAX_SIT_BITMAP_SIZE_IN_CKPT) {
>> - max_nat_bitmap_size = CHECKSUM_OFFSET -
>> - sizeof(struct f2fs_checkpoint) + 1;
>> - set_sb(cp_payload, F2FS_BLK_ALIGN(max_sit_bitmap_size));
>> + max_nat_bitmap_size = (get_sb(segment_count_nat) <<
>> + log_blks_per_seg) / 8;
>> +
>> + set_sb(segment_count_nat, get_sb(segment_count_nat) * 2);
>> +
>> + /* use cp_payload if free space of f2fs_checkpoint is not enough */
>> + if (max_sit_bitmap_size + max_nat_bitmap_size >
>> + MAX_BITMAP_SIZE_IN_CKPT) {
>> + u_int32_t diff = max_sit_bitmap_size + max_nat_bitmap_size -
>> + MAX_BITMAP_SIZE_IN_CKPT;
>
> The same as above. :)
>
>
>
> Thanks,
>
>> + set_sb(cp_payload, F2FS_BLK_ALIGN(diff));
>> } else {
>> - max_nat_bitmap_size =
>> - CHECKSUM_OFFSET - sizeof(struct f2fs_checkpoint) + 1
>> - - max_sit_bitmap_size;
>> set_sb(cp_payload, 0);
>> }
>>
>> - max_nat_segments = (max_nat_bitmap_size * 8) >> log_blks_per_seg;
>> -
>> - if (get_sb(segment_count_nat) > max_nat_segments)
>> - set_sb(segment_count_nat, max_nat_segments);
>> -
>> - set_sb(segment_count_nat, get_sb(segment_count_nat) * 2);
>> -
>> set_sb(ssa_blkaddr, get_sb(nat_blkaddr) + get_sb(segment_count_nat) *
>> c.blks_per_seg);
>>
>> --
>> 2.15.0.55.gc2ece9dc4de6
>>
>>
>>
>
>
> .
>
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