Re: [PATCH v2] mkfs.f2fs: expand scalability of nat bitmap

From: Chao Yu
Date: Tue Jan 23 2018 - 21:33:05 EST

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On 2018/1/24 10:22, Jaegeuk Kim wrote:
> On 01/24, Chao Yu wrote:
>> On 2018/1/24 6:19, Jaegeuk Kim wrote:
>>> On 01/23, Jaegeuk Kim wrote:
>>>> On 01/23, Chao Yu wrote:
>>>>> On 2018/1/23 7:00, Jaegeuk Kim wrote:
>>>>>> On 01/17, Chao Yu wrote:
>>>>>>> Hi Jaegeuk,
>>>>>>>
>>>>>>> On 2018/1/17 8:47, Jaegeuk Kim wrote:
>>>>>>>> Hi Chao,
>>>>>>>>
>>>>>>>> On 01/15, 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
>>>>>>>
>>>>>>> As you see, nat_segment count will reduce when image size increases
>>>>>>> starting from 64GB, that means nat segment count will not monotonously
>>>>>>> increase when image size is increasing, so it would be better to active
>>>>>>> this when image size is larger than 32GB?
>>>>>>>
>>>>>>> IMO, configuring basic nid ratio to fixed value like ext4 ("free inode" :
>>>>>>> "free block" is about 1 : 4) would be better:
>>>>>>> a. It will be easy for user to predict nid count or nat segment count with
>>>>>>> fix-sized image;
>>>>>>> b. If user wants to reserve more nid count, we can support -N option in
>>>>>>> mkfs.f2fs to specify total nid count as user wish.
>>>>>>
>>>>>> My concern is about a CTS failure in terms of # of free inodes.
>>>>>
>>>>> You mean testSaneInodes()?
>>>>>
>>>>> final long maxsize = stat.f_blocks * stat.f_frsize;
>>>>> final long maxInodes = maxsize / 4096;
>>>>> final long minsize = stat.f_bavail * stat.f_frsize;
>>>>> final long minInodes = minsize / 32768;
>>>>>
>>>>> The range is about [1/8, 1], so our 20% threshold can just let it passed,
>>>>> right?
>>>>
>>>> Yes, thanks for checking the codes. Let me play with this for some time.
>>>
>>> It simply triggers a panic, if kernel does not have the patch to detect the
>>> feature. Hmm...
>>
>> Yes, because we have changed disk layout of nat/sit_version_bitmap in
>> mkfs.f2fs, if kernel can not detect that, we will encounter panic simply.
>
> , which means we can't do this by default at least.

Oh, right, we need to consider to keep backward compactibility for old
kernel in mkfs.f2fs by default, what about adding a new option to enable
this just for new kernel?

Thanks,

>
>>
>> Thanks,
>>
>>>
>>> Thanks,
>>>
>>>>
>>>> Thanks,
>>>>
>>>>>
>>>>> Thanks,
>>>>>
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>>>
>>>>>>> How do you think?
>>>>>>>
>>>>>>> Thanks,
>>>>>>>
>>>>>>>>> 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
>>>>>>>>
>>>>>>>> Can we activate this, if size is larger than 256GB or something around that?
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>>
>>>>>>>>> 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@xxxxxxxxxx>
>>>>>>>>> ---
>>>>>>>>> v2:
>>>>>>>>> - add CP_LARGE_NAT_BITMAP_FLAG flag to indicate new layout of nat/sit bitmap.
>>>>>>>>> fsck/f2fs.h | 19 +++++++++++++------
>>>>>>>>> fsck/resize.c | 35 +++++++++++++++++------------------
>>>>>>>>> include/f2fs_fs.h | 8 ++++++--
>>>>>>>>> lib/libf2fs.c | 1 +
>>>>>>>>> mkfs/f2fs_format.c | 45 +++++++++++++++++++++++----------------------
>>>>>>>>> 5 files changed, 60 insertions(+), 48 deletions(-)
>>>>>>>>>
>>>>>>>>> diff --git a/fsck/f2fs.h b/fsck/f2fs.h
>>>>>>>>> index f5970d9dafc0..8a5ce365282d 100644
>>>>>>>>> --- a/fsck/f2fs.h
>>>>>>>>> +++ b/fsck/f2fs.h
>>>>>>>>> @@ -239,6 +239,12 @@ static inline unsigned int ofs_of_node(struct f2fs_node *node_blk)
>>>>>>>>> return flag >> OFFSET_BIT_SHIFT;
>>>>>>>>> }
>>>>>>>>>
>>>>>>>>> +static inline bool is_set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
>>>>>>>>> +{
>>>>>>>>> + unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);
>>>>>>>>> + return ckpt_flags & f ? 1 : 0;
>>>>>>>>> +}
>>>>>>>>> +
>>>>>>>>> static inline unsigned long __bitmap_size(struct f2fs_sb_info *sbi, int flag)
>>>>>>>>> {
>>>>>>>>> struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
>>>>>>>>> @@ -256,6 +262,13 @@ static inline void *__bitmap_ptr(struct f2fs_sb_info *sbi, int flag)
>>>>>>>>> {
>>>>>>>>> struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
>>>>>>>>> int offset;
>>>>>>>>> +
>>>>>>>>> + if (is_set_ckpt_flags(ckpt, CP_LARGE_NAT_BITMAP_FLAG)) {
>>>>>>>>> + offset = (flag == SIT_BITMAP) ?
>>>>>>>>> + le32_to_cpu(ckpt->nat_ver_bitmap_bytesize) : 0;
>>>>>>>>> + return &ckpt->sit_nat_version_bitmap + offset;
>>>>>>>>> + }
>>>>>>>>> +
>>>>>>>>> if (le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload) > 0) {
>>>>>>>>> if (flag == NAT_BITMAP)
>>>>>>>>> return &ckpt->sit_nat_version_bitmap;
>>>>>>>>> @@ -268,12 +281,6 @@ static inline void *__bitmap_ptr(struct f2fs_sb_info *sbi, int flag)
>>>>>>>>> }
>>>>>>>>> }
>>>>>>>>>
>>>>>>>>> -static inline bool is_set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
>>>>>>>>> -{
>>>>>>>>> - unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);
>>>>>>>>> - return ckpt_flags & f ? 1 : 0;
>>>>>>>>> -}
>>>>>>>>> -
>>>>>>>>> static inline block_t __start_cp_addr(struct f2fs_sb_info *sbi)
>>>>>>>>> {
>>>>>>>>> block_t start_addr = le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_blkaddr);
>>>>>>>>> diff --git a/fsck/resize.c b/fsck/resize.c
>>>>>>>>> index 143ad5d3c0a1..f3547c86f351 100644
>>>>>>>>> --- a/fsck/resize.c
>>>>>>>>> +++ b/fsck/resize.c
>>>>>>>>> @@ -13,10 +13,10 @@ static int get_new_sb(struct f2fs_super_block *sb)
>>>>>>>>> {
>>>>>>>>> u_int32_t zone_size_bytes, zone_align_start_offset;
>>>>>>>>> u_int32_t blocks_for_sit, blocks_for_nat, blocks_for_ssa;
>>>>>>>>> - u_int32_t sit_segments, diff, total_meta_segments;
>>>>>>>>> + u_int32_t sit_segments, nat_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 +47,15 @@ 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));
>>>>>>>>> + nat_segments = SEG_ALIGN(blocks_for_nat) *
>>>>>>>>> + DEFAULT_NAT_ENTRY_RATIO / 100;
>>>>>>>>> + set_sb(segment_count_nat, nat_segments ? nat_segments : 1);
>>>>>>>>> +
>>>>>>>>> + max_nat_bitmap_size = (get_sb(segment_count_nat) <<
>>>>>>>>> + get_sb(log_blocks_per_seg)) / 8;
>>>>>>>>> + set_sb(segment_count_nat, get_sb(segment_count_nat) * 2);
>>>>>>>>> +
>>>>>>>>> + c.large_nat_bitmap = 1;
>>>>>>>>>
>>>>>>>>> sit_bitmap_size = ((get_sb(segment_count_sit) / 2) <<
>>>>>>>>> get_sb(log_blocks_per_seg)) / 8;
>>>>>>>>> @@ -56,25 +64,16 @@ 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));
>>>>>>>>> + /* 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;
>>>>>>>>> + 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..edf351412702 100644
>>>>>>>>> --- a/include/f2fs_fs.h
>>>>>>>>> +++ b/include/f2fs_fs.h
>>>>>>>>> @@ -362,6 +362,7 @@ struct f2fs_configuration {
>>>>>>>>> int preen_mode;
>>>>>>>>> int ro;
>>>>>>>>> int preserve_limits; /* preserve quota limits */
>>>>>>>>> + int large_nat_bitmap;
>>>>>>>>> __le32 feature; /* defined features */
>>>>>>>>>
>>>>>>>>> /* defragmentation parameters */
>>>>>>>>> @@ -613,6 +614,7 @@ struct f2fs_super_block {
>>>>>>>>> /*
>>>>>>>>> * For checkpoint
>>>>>>>>> */
>>>>>>>>> +#define CP_LARGE_NAT_BITMAP_FLAG 0x00000200
>>>>>>>>> #define CP_TRIMMED_FLAG 0x00000100
>>>>>>>>> #define CP_NAT_BITS_FLAG 0x00000080
>>>>>>>>> #define CP_CRC_RECOVERY_FLAG 0x00000040
>>>>>>>>> @@ -657,8 +659,8 @@ 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 +848,8 @@ 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/lib/libf2fs.c b/lib/libf2fs.c
>>>>>>>>> index ffdbccb34627..e8b1842b7391 100644
>>>>>>>>> --- a/lib/libf2fs.c
>>>>>>>>> +++ b/lib/libf2fs.c
>>>>>>>>> @@ -623,6 +623,7 @@ void f2fs_init_configuration(void)
>>>>>>>>> c.ro = 0;
>>>>>>>>> c.kd = -1;
>>>>>>>>> c.dry_run = 0;
>>>>>>>>> + c.large_nat_bitmap = 0;
>>>>>>>>> c.fixed_time = -1;
>>>>>>>>> }
>>>>>>>>>
>>>>>>>>> diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
>>>>>>>>> index a13000184300..23eaf40c5962 100644
>>>>>>>>> --- a/mkfs/f2fs_format.c
>>>>>>>>> +++ b/mkfs/f2fs_format.c
>>>>>>>>> @@ -151,13 +151,13 @@ static int f2fs_prepare_super_block(void)
>>>>>>>>> u_int32_t log_sectorsize, log_sectors_per_block;
>>>>>>>>> u_int32_t log_blocksize, log_blks_per_seg;
>>>>>>>>> u_int32_t segment_size_bytes, zone_size_bytes;
>>>>>>>>> - u_int32_t sit_segments;
>>>>>>>>> + u_int32_t sit_segments, nat_segments;
>>>>>>>>> u_int32_t blocks_for_sit, blocks_for_nat, blocks_for_ssa;
>>>>>>>>> u_int32_t total_valid_blks_available;
>>>>>>>>> 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 +272,18 @@ 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));
>>>>>>>>> + nat_segments = SEG_ALIGN(blocks_for_nat) *
>>>>>>>>> + DEFAULT_NAT_ENTRY_RATIO / 100;
>>>>>>>>> +
>>>>>>>>> + set_sb(segment_count_nat, nat_segments ? nat_segments : 1);
>>>>>>>>> +
>>>>>>>>> + 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);
>>>>>>>>> +
>>>>>>>>> + c.large_nat_bitmap = 1;
>>>>>>>>> +
>>>>>>>>> /*
>>>>>>>>> * The number of node segments should not be exceeded a "Threshold".
>>>>>>>>> * This number resizes NAT bitmap area in a CP page.
>>>>>>>>> @@ -286,29 +297,16 @@ 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));
>>>>>>>>> + /* 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;
>>>>>>>>> + 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);
>>>>>>>>>
>>>>>>>>> @@ -622,6 +620,9 @@ static int f2fs_write_check_point_pack(void)
>>>>>>>>> if (c.trimmed)
>>>>>>>>> flags |= CP_TRIMMED_FLAG;
>>>>>>>>>
>>>>>>>>> + if (c.large_nat_bitmap)
>>>>>>>>> + flags |= CP_LARGE_NAT_BITMAP_FLAG;
>>>>>>>>> +
>>>>>>>>> set_cp(ckpt_flags, flags);
>>>>>>>>> set_cp(cp_pack_start_sum, 1 + get_sb(cp_payload));
>>>>>>>>> set_cp(valid_node_count, 1 + quota_inum);
>>>>>>>>> --
>>>>>>>>> 2.15.0.55.gc2ece9dc4de6
>>>>>>>>
>>>>>>>> .
>>>>>>>>
>>>>>>
>>>>>> .
>>>>>>
>>>
>>> .
>>>
>
> .
>

Next message: Jia-Ju Bai: "[PATCH] kernel: x86: early-quirks: Replace mdelay with usleep_range in apple_airport_reset"
Previous message: Shuah Khan: "[PATCH 4.9] usbip: Fix potential format overflow in userspace tools"
In reply to: Jaegeuk Kim: "Re: [PATCH v2] mkfs.f2fs: expand scalability of nat bitmap"
Next in thread: Jaegeuk Kim: "Re: [PATCH v2] mkfs.f2fs: expand scalability of nat bitmap"
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