Re: [f2fs-dev] [PATCH] f2fs: large volume support

[Changman Lee <cm224.lee@samsung.com>]

On 수, 2014-05-21 at 13:33 +0900, Jaegeuk Kim wrote:
> Hi Changman,
> 
> 2014-05-12 (월), 15:59 +0900, Changman Lee:
> > f2fs's cp has one page which consists of struct f2fs_checkpoint and
> > version bitmap of sit and nat. To support lots of segments, we need more
> > blocks for sit bitmap. So let's arrange sit bitmap as following:
> > +-----------------+------------+
> > | f2fs_checkpoint | sit bitmap |
> > | + nat bitmap    |            |
> > +-----------------+------------+
> > 0                 4k        N blocks
> > 
> > Signed-off-by: Changman Lee <cm224.lee@samsung.com>
> > ---
> >  fs/f2fs/checkpoint.c    |   47 ++++++++++++++++++++++++++++++++++++++++++++---
> >  fs/f2fs/f2fs.h          |   13 +++++++++++--
> >  include/linux/f2fs_fs.h |    2 ++
> >  3 files changed, 57 insertions(+), 5 deletions(-)
> > 
> > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> > index fe968c7..f418243 100644
> > --- a/fs/f2fs/checkpoint.c
> > +++ b/fs/f2fs/checkpoint.c
> > @@ -544,6 +544,32 @@ int get_valid_checkpoint(struct f2fs_sb_info *sbi)
> >  	cp_block = (struct f2fs_checkpoint *)page_address(cur_page);
> >  	memcpy(sbi->ckpt, cp_block, blk_size);
> >  
> > +	if (is_set_ckpt_flags(sbi->ckpt, CP_LARGE_VOL_FLAG)) {
> > +		int i, cp_blks;
> > +		block_t cp_blk_no;
> > +
> > +		cp_blk_no = le32_to_cpu(fsb->cp_blkaddr);
> > +		if (cur_page == cp2)
> > +			cp_blk_no += 1 << le32_to_cpu(fsb->log_blocks_per_seg);
> > +
> > +		cp_blks = 1 + F2FS_BLK_ALIGN(cp_block->sit_ver_bitmap_bytesize);
> 
> Should covert le32_to_cpu(cp_block->sit_ver_bitmap_bytesize).
> 
Got it.
> > +
> > +		kfree(sbi->ckpt);
> > +		sbi->ckpt = kzalloc(cp_blks * blk_size, GFP_KERNEL);
> 
> Why does it have to reallocate this and not to handle -ENOMEM correctly?

I think it's more simple than using another variable to point
sit_ver_bitmap and it doesn't require alloc and free for the variable.

> 
> > +
> > +		memcpy(sbi->ckpt, cp_block, blk_size);
> > +
> > +		for (i = 1; i < cp_blks; i++) {
> > +			void *sit_bitmap_ptr;
> > +			unsigned char *ckpt = (unsigned char *)sbi->ckpt;
> > +
> > +			cur_page = get_meta_page(sbi, cp_blk_no + i);
> > +			sit_bitmap_ptr = page_address(cur_page);
> > +			memcpy(ckpt + i * blk_size, sit_bitmap_ptr, blk_size);
> > +			f2fs_put_page(cur_page, 1);
> > +		}
> > +	}
> > +
> >  	f2fs_put_page(cp1, 1);
> >  	f2fs_put_page(cp2, 1);
> >  	return 0;
> > @@ -736,6 +762,7 @@ static void do_checkpoint(struct f2fs_sb_info *sbi, bool is_umount)
> >  	__u32 crc32 = 0;
> >  	void *kaddr;
> >  	int i;
> > +	int sit_bitmap_blks = 0;
> >  
> >  	/*
> >  	 * This avoids to conduct wrong roll-forward operations and uses
> > @@ -786,16 +813,21 @@ static void do_checkpoint(struct f2fs_sb_info *sbi, bool is_umount)
> >  
> >  	orphan_blocks = (sbi->n_orphans + F2FS_ORPHANS_PER_BLOCK - 1)
> >  					/ F2FS_ORPHANS_PER_BLOCK;
> > -	ckpt->cp_pack_start_sum = cpu_to_le32(1 + orphan_blocks);
> > +	if (is_set_ckpt_flags(ckpt, CP_LARGE_VOL_FLAG))
> > +		sit_bitmap_blks = F2FS_BLK_ALIGN(ckpt->sit_ver_bitmap_bytesize);
> > +	ckpt->cp_pack_start_sum = cpu_to_le32(1 + sit_bitmap_blks +
> > +			orphan_blocks);
> >  
> >  	if (is_umount) {
> >  		set_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
> >  		ckpt->cp_pack_total_block_count = cpu_to_le32(2 +
> > -			data_sum_blocks + orphan_blocks + NR_CURSEG_NODE_TYPE);
> > +				sit_bitmap_blks + data_sum_blocks +
> > +				orphan_blocks + NR_CURSEG_NODE_TYPE);
> >  	} else {
> >  		clear_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
> >  		ckpt->cp_pack_total_block_count = cpu_to_le32(2 +
> > -			data_sum_blocks + orphan_blocks);
> > +				sit_bitmap_blks + data_sum_blocks +
> > +				orphan_blocks);
> >  	}
> >  
> >  	if (sbi->n_orphans)
> > @@ -821,6 +853,15 @@ static void do_checkpoint(struct f2fs_sb_info *sbi, bool is_umount)
> >  	set_page_dirty(cp_page);
> >  	f2fs_put_page(cp_page, 1);
> >  
> > +	for (i = 1; i < 1 + sit_bitmap_blks; i++) {
> > +		cp_page = grab_meta_page(sbi, start_blk++);
> > +		kaddr = page_address(cp_page);
> > +		memcpy(kaddr, (char *)ckpt + i * F2FS_BLKSIZE,
> > +				(1 << sbi->log_blocksize));
> > +		set_page_dirty(cp_page);
> > +		f2fs_put_page(cp_page, 1);
> > +	}
> > +
> >  	if (sbi->n_orphans) {
> >  		write_orphan_inodes(sbi, start_blk);
> >  		start_blk += orphan_blocks;
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index 676a2c6..9e147ae 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -764,9 +764,18 @@ static inline unsigned long __bitmap_size(struct f2fs_sb_info *sbi, int flag)
> >  static inline void *__bitmap_ptr(struct f2fs_sb_info *sbi, int flag)
> >  {
> >  	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
> > -	int offset = (flag == NAT_BITMAP) ?
> > +	int offset;
> > +
> > +	if (ckpt->ckpt_flags & CP_LARGE_VOL_FLAG) {
> 
> Should call is_set_ckpt_flag(ckpt, CP_LARGE_VOL_FLAG) to avoid endian
> conversion issue.
> 
> Thanks,
> 

My mistake. Thanks.

> > +		if (flag == NAT_BITMAP)
> > +			return &ckpt->sit_nat_version_bitmap;
> > +		else
> > +			return ((unsigned char *)ckpt + F2FS_BLKSIZE);
> > +	} else {
> > +		offset = (flag == NAT_BITMAP) ?
> >  			le32_to_cpu(ckpt->sit_ver_bitmap_bytesize) : 0;
> > -	return &ckpt->sit_nat_version_bitmap + offset;
> > +		return &ckpt->sit_nat_version_bitmap + offset;
> > +	}
> >  }
> >  
> >  static inline block_t __start_cp_addr(struct f2fs_sb_info *sbi)
> > diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
> > index 8c03f71..0f0b788 100644
> > --- a/include/linux/f2fs_fs.h
> > +++ b/include/linux/f2fs_fs.h
> > @@ -19,6 +19,7 @@
> >  #define F2FS_LOG_SECTORS_PER_BLOCK	3	/* 4KB: F2FS_BLKSIZE */
> >  #define F2FS_BLKSIZE			4096	/* support only 4KB block */
> >  #define F2FS_MAX_EXTENSION		64	/* # of extension entries */
> > +#define F2FS_BLK_ALIGN(x)	(((x) + F2FS_BLKSIZE - 1) / F2FS_BLKSIZE)
> >  
> >  #define NULL_ADDR		((block_t)0)	/* used as block_t addresses */
> >  #define NEW_ADDR		((block_t)-1)	/* used as block_t addresses */
> > @@ -80,6 +81,7 @@ struct f2fs_super_block {
> >  /*
> >   * For checkpoint
> >   */
> > +#define CP_LARGE_VOL_FLAG	0x00000010
> >  #define CP_ERROR_FLAG		0x00000008
> >  #define CP_COMPACT_SUM_FLAG	0x00000004
> >  #define CP_ORPHAN_PRESENT_FLAG	0x00000002
> 


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