Commit f8e2f32b authored by Daeho Jeong's avatar Daeho Jeong Committed by Jaegeuk Kim
Browse files

f2fs: introduce sysfs atomic write statistics 



introduce the below 4 new sysfs node for atomic write statistics.
- current_atomic_write: the total current atomic write block count,
                        which is not committed yet.
- peak_atomic_write: the peak value of total current atomic write block
                     count after boot.
- committed_atomic_block: the accumulated total committed atomic write
                          block count after boot.
- revoked_atomic_block: the accumulated total revoked atomic write block
                        count after boot.

Signed-off-by: default avatarDaeho Jeong <daehojeong@google.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 1adaa71e

Documentation/ABI/testing/sysfs-fs-f2fs

+24 −0
Original line number Diff line number Diff line
@@ -586,3 +586,27 @@ Date: June 2022 
Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>

Description:	Shows the number of unusable blocks in a section which was defined by

		the zone capacity reported by underlying zoned device.



What:		/sys/fs/f2fs/<disk>/current_atomic_write

Date:		July 2022

Contact:	"Daeho Jeong" <daehojeong@google.com>

Description:	Show the total current atomic write block count, which is not committed yet.

		This is a read-only entry.



What:		/sys/fs/f2fs/<disk>/peak_atomic_write

Date:		July 2022

Contact:	"Daeho Jeong" <daehojeong@google.com>

Description:	Show the peak value of total current atomic write block count after boot.

		If you write "0" here, you can initialize to "0".



What:		/sys/fs/f2fs/<disk>/committed_atomic_block

Date:		July 2022

Contact:	"Daeho Jeong" <daehojeong@google.com>

Description:	Show the accumulated total committed atomic write block count after boot.

		If you write "0" here, you can initialize to "0".



What:		/sys/fs/f2fs/<disk>/revoked_atomic_block

Date:		July 2022

Contact:	"Daeho Jeong" <daehojeong@google.com>

Description:	Show the accumulated total revoked atomic write block count after boot.

		If you write "0" here, you can initialize to "0".

fs/f2fs/data.c

+4 −3
Original line number Diff line number Diff line
@@ -3406,12 +3406,11 @@ static int prepare_atomic_write_begin(struct f2fs_sb_info *sbi, 
	struct inode *cow_inode = F2FS_I(inode)->cow_inode;

	pgoff_t index = page->index;

	int err = 0;

	block_t ori_blk_addr;

	block_t ori_blk_addr = NULL_ADDR;



	/* If pos is beyond the end of file, reserve a new block in COW inode */

	if ((pos & PAGE_MASK) >= i_size_read(inode))

		return __reserve_data_block(cow_inode, index, blk_addr,

					node_changed);

		goto reserve_block;



	/* Look for the block in COW inode first */

	err = __find_data_block(cow_inode, index, blk_addr);
@@ -3425,10 +3424,12 @@ static int prepare_atomic_write_begin(struct f2fs_sb_info *sbi, 
	if (err)

		return err;



reserve_block:

	/* Finally, we should reserve a new block in COW inode for the update */

	err = __reserve_data_block(cow_inode, index, blk_addr, node_changed);

	if (err)

		return err;

	inc_atomic_write_cnt(inode);



	if (ori_blk_addr != NULL_ADDR)

		*blk_addr = ori_blk_addr;

fs/f2fs/f2fs.h

+30 −0
Original line number Diff line number Diff line
@@ -813,6 +813,8 @@ struct f2fs_inode_info { 
	unsigned char i_compress_level;		/* compress level (lz4hc,zstd) */

	unsigned short i_compress_flag;		/* compress flag */

	unsigned int i_cluster_size;		/* cluster size */



	unsigned int atomic_write_cnt;

};



static inline void get_extent_info(struct extent_info *ext,
@@ -1813,6 +1815,12 @@ struct f2fs_sb_info { 
	int max_fragment_chunk;			/* max chunk size for block fragmentation mode */

	int max_fragment_hole;			/* max hole size for block fragmentation mode */



	/* For atomic write statistics */

	atomic64_t current_atomic_write;

	s64 peak_atomic_write;

	u64 committed_atomic_block;

	u64 revoked_atomic_block;



#ifdef CONFIG_F2FS_FS_COMPRESSION

	struct kmem_cache *page_array_slab;	/* page array entry */

	unsigned int page_array_slab_size;	/* default page array slab size */
@@ -2427,6 +2435,28 @@ static inline void inode_dec_dirty_pages(struct inode *inode) 
		dec_page_count(F2FS_I_SB(inode), F2FS_DIRTY_QDATA);

}



static inline void inc_atomic_write_cnt(struct inode *inode)

{

	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);

	struct f2fs_inode_info *fi = F2FS_I(inode);

	u64 current_write;



	fi->atomic_write_cnt++;

	atomic64_inc(&sbi->current_atomic_write);

	current_write = atomic64_read(&sbi->current_atomic_write);

	if (current_write > sbi->peak_atomic_write)

		sbi->peak_atomic_write = current_write;

}



static inline void release_atomic_write_cnt(struct inode *inode)

{

	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);

	struct f2fs_inode_info *fi = F2FS_I(inode);



	atomic64_sub(fi->atomic_write_cnt, &sbi->current_atomic_write);

	fi->atomic_write_cnt = 0;

}



static inline s64 get_pages(struct f2fs_sb_info *sbi, int count_type)

{

	return atomic_read(&sbi->nr_pages[count_type]);

fs/f2fs/file.c

+1 −0
Original line number Diff line number Diff line
@@ -2075,6 +2075,7 @@ static int f2fs_ioc_start_atomic_write(struct file *filp) 
	f2fs_update_time(sbi, REQ_TIME);

	fi->atomic_write_task = current;

	stat_update_max_atomic_write(inode);

	fi->atomic_write_cnt = 0;

out:

	inode_unlock(inode);

	mnt_drop_write_file(filp);

fs/f2fs/segment.c

+6 −0
Original line number Diff line number Diff line
@@ -196,6 +196,7 @@ void f2fs_abort_atomic_write(struct inode *inode, bool clean) 
		clear_inode_flag(fi->cow_inode, FI_ATOMIC_FILE);

		iput(fi->cow_inode);

		fi->cow_inode = NULL;

		release_atomic_write_cnt(inode);

		clear_inode_flag(inode, FI_ATOMIC_FILE);



		spin_lock(&sbi->inode_lock[ATOMIC_FILE]);
@@ -335,6 +336,11 @@ static int __f2fs_commit_atomic_write(struct inode *inode) 
	}



out:

	if (ret)

		sbi->revoked_atomic_block += fi->atomic_write_cnt;

	else

		sbi->committed_atomic_block += fi->atomic_write_cnt;



	__complete_revoke_list(inode, &revoke_list, ret ? true : false);



	return ret;