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

From: Jaegeuk Kim
Date: Mon Jan 22 2018 - 18:00:35 EST

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In reply to: Chao Yu: "Re: [PATCH v2] mkfs.f2fs: expand scalability of nat bitmap"
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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.

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: Jin, Yao: "Re: [PATCH] perf util: Use target->per_thread and target->system_wide flags"
Previous message: Jaegeuk Kim: "Re: [PATCH v5] f2fs: add an ioctl to disable GC for specific file"
In reply to: Chao Yu: "Re: [PATCH v2] mkfs.f2fs: expand scalability of nat bitmap"
Next in thread: Chao Yu: "Re: [PATCH v2] mkfs.f2fs: expand scalability of nat bitmap"
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