On 2020/10/29 下午10:27, David Sterba wrote:
> btrfs_get_16 shows up in the system performance profiles (helper to read
> 16bit values from on-disk structures). This is partially because of the
> checksum size that's frequently read along with data reads/writes, other
> u16 uses are from item size or directory entries.
> 
> Replace all calls to btrfs_super_csum_size by the cached value from
> fs_info.
> 
> Signed-off-by: David Sterba <dsterba@suse.com>

Reviewed-by: Qu Wenruo <wqu@suse.com>

Thanks,
Qu

> ---
>  fs/btrfs/btrfs_inode.h     |  3 +--
>  fs/btrfs/check-integrity.c |  2 +-
>  fs/btrfs/compression.c     |  6 +++---
>  fs/btrfs/disk-io.c         |  6 +++---
>  fs/btrfs/extent_io.c       |  2 +-
>  fs/btrfs/file-item.c       | 14 +++++++-------
>  fs/btrfs/inode.c           |  6 +++---
>  fs/btrfs/ordered-data.c    |  2 +-
>  fs/btrfs/ordered-data.h    |  2 +-
>  fs/btrfs/scrub.c           |  2 +-
>  fs/btrfs/tree-checker.c    |  2 +-
>  11 files changed, 23 insertions(+), 24 deletions(-)
> 
> diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
> index 92dd86bceae3..f1c9cbd0d184 100644
> --- a/fs/btrfs/btrfs_inode.h
> +++ b/fs/btrfs/btrfs_inode.h
> @@ -341,8 +341,7 @@ static inline void btrfs_print_data_csum_error(struct btrfs_inode *inode,
>  		u64 logical_start, u8 *csum, u8 *csum_expected, int mirror_num)
>  {
>  	struct btrfs_root *root = inode->root;
> -	struct btrfs_super_block *sb = root->fs_info->super_copy;
> -	const u16 csum_size = btrfs_super_csum_size(sb);
> +	const u16 csum_size = root->fs_info->csum_size;
>  
>  	/* Output minus objectid, which is more meaningful */
>  	if (root->root_key.objectid >= BTRFS_LAST_FREE_OBJECTID)
> diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
> index 81a8c87a5afb..2905fe5974e6 100644
> --- a/fs/btrfs/check-integrity.c
> +++ b/fs/btrfs/check-integrity.c
> @@ -660,7 +660,7 @@ static int btrfsic_process_superblock(struct btrfsic_state *state,
>  		return -1;
>  	}
>  
> -	state->csum_size = btrfs_super_csum_size(selected_super);
> +	state->csum_size = state->fs_info->csum_size;
>  
>  	for (pass = 0; pass < 3; pass++) {
>  		int num_copies;
> diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
> index 972fb68a85ac..00bbd859f31b 100644
> --- a/fs/btrfs/compression.c
> +++ b/fs/btrfs/compression.c
> @@ -131,7 +131,7 @@ static int btrfs_decompress_bio(struct compressed_bio *cb);
>  static inline int compressed_bio_size(struct btrfs_fs_info *fs_info,
>  				      unsigned long disk_size)
>  {
> -	u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +	const u16 csum_size = fs_info->csum_size;
>  
>  	return sizeof(struct compressed_bio) +
>  		(DIV_ROUND_UP(disk_size, fs_info->sectorsize)) * csum_size;
> @@ -142,7 +142,7 @@ static int check_compressed_csum(struct btrfs_inode *inode, struct bio *bio,
>  {
>  	struct btrfs_fs_info *fs_info = inode->root->fs_info;
>  	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
> -	const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +	const u16 csum_size = fs_info->csum_size;
>  	struct page *page;
>  	unsigned long i;
>  	char *kaddr;
> @@ -628,7 +628,7 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
>  	struct extent_map *em;
>  	blk_status_t ret = BLK_STS_RESOURCE;
>  	int faili = 0;
> -	const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +	const u16 csum_size = fs_info->csum_size;
>  	u8 *sums;
>  
>  	em_tree = &BTRFS_I(inode)->extent_tree;
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index f870e252aa37..e22e8de31c07 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -319,7 +319,7 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
>  	crypto_shash_digest(shash, raw_disk_sb + BTRFS_CSUM_SIZE,
>  			    BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE, result);
>  
> -	if (memcmp(disk_sb->csum, result, btrfs_super_csum_size(disk_sb)))
> +	if (memcmp(disk_sb->csum, result, fs_info->csum_size))
>  		return 1;
>  
>  	return 0;
> @@ -452,7 +452,7 @@ static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct page *page)
>  	u64 start = page_offset(page);
>  	u64 found_start;
>  	u8 result[BTRFS_CSUM_SIZE];
> -	u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +	const u16 csum_size = fs_info->csum_size;
>  	struct extent_buffer *eb;
>  	int ret;
>  
> @@ -541,7 +541,7 @@ int btrfs_validate_metadata_buffer(struct btrfs_io_bio *io_bio, u64 phy_offset,
>  
>  	eb = (struct extent_buffer *)page->private;
>  	fs_info = eb->fs_info;
> -	csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +	csum_size = fs_info->csum_size;
>  
>  	/* the pending IO might have been the only thing that kept this buffer
>  	 * in memory.  Make sure we have a ref for all this other checks
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index cd27a2a4f717..e943fff35608 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -2685,7 +2685,7 @@ blk_status_t btrfs_submit_read_repair(struct inode *inode,
>  	repair_bio->bi_private = failed_bio->bi_private;
>  
>  	if (failed_io_bio->csum) {
> -		const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +		const u16 csum_size = fs_info->csum_size;
>  
>  		repair_io_bio->csum = repair_io_bio->csum_inline;
>  		memcpy(repair_io_bio->csum,
> diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
> index ed750dd8a115..a4a68a224342 100644
> --- a/fs/btrfs/file-item.c
> +++ b/fs/btrfs/file-item.c
> @@ -181,7 +181,7 @@ btrfs_lookup_csum(struct btrfs_trans_handle *trans,
>  	struct btrfs_csum_item *item;
>  	struct extent_buffer *leaf;
>  	u64 csum_offset = 0;
> -	u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +	const u16 csum_size = fs_info->csum_size;
>  	int csums_in_item;
>  
>  	file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
> @@ -270,7 +270,7 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
>  	u32 diff;
>  	int nblocks;
>  	int count = 0;
> -	u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +	const u16 csum_size = fs_info->csum_size;
>  
>  	if (!fs_info->csum_root || (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
>  		return BLK_STS_OK;
> @@ -409,7 +409,7 @@ int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
>  	int ret;
>  	size_t size;
>  	u64 csum_end;
> -	u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +	const u16 csum_size = fs_info->csum_size;
>  
>  	ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
>  	       IS_ALIGNED(end + 1, fs_info->sectorsize));
> @@ -541,7 +541,7 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
>  	int i;
>  	u64 offset;
>  	unsigned nofs_flag;
> -	const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +	const u16 csum_size = fs_info->csum_size;
>  
>  	nofs_flag = memalloc_nofs_save();
>  	sums = kvzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),
> @@ -639,7 +639,7 @@ static noinline void truncate_one_csum(struct btrfs_fs_info *fs_info,
>  				       u64 bytenr, u64 len)
>  {
>  	struct extent_buffer *leaf;
> -	u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +	const u16 csum_size = fs_info->csum_size;
>  	u64 csum_end;
>  	u64 end_byte = bytenr + len;
>  	u32 blocksize_bits = fs_info->sectorsize_bits;
> @@ -693,7 +693,7 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
>  	u64 csum_end;
>  	struct extent_buffer *leaf;
>  	int ret;
> -	u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +	const u16 csum_size = fs_info->csum_size;
>  	u32 blocksize_bits = fs_info->sectorsize_bits;
>  
>  	ASSERT(root == fs_info->csum_root ||
> @@ -848,7 +848,7 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
>  	int index = 0;
>  	int found_next;
>  	int ret;
> -	u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +	const u16 csum_size = fs_info->csum_size;
>  
>  	path = btrfs_alloc_path();
>  	if (!path)
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 5582c1c9c007..549dca610f8c 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -2796,7 +2796,7 @@ static int check_data_csum(struct inode *inode, struct btrfs_io_bio *io_bio,
>  	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
>  	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
>  	char *kaddr;
> -	u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +	const u16 csum_size = fs_info->csum_size;
>  	u8 *csum_expected;
>  	u8 csum[BTRFS_CSUM_SIZE];
>  
> @@ -7738,7 +7738,7 @@ static inline blk_status_t btrfs_submit_dio_bio(struct bio *bio,
>  
>  		csum_offset = file_offset - dip->logical_offset;
>  		csum_offset >>= fs_info->sectorsize_bits;
> -		csum_offset *= btrfs_super_csum_size(fs_info->super_copy);
> +		csum_offset *= fs_info->csum_size;
>  		btrfs_io_bio(bio)->csum = dip->csums + csum_offset;
>  	}
>  map:
> @@ -7763,7 +7763,7 @@ static struct btrfs_dio_private *btrfs_create_dio_private(struct bio *dio_bio,
>  	dip_size = sizeof(*dip);
>  	if (!write && csum) {
>  		struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
> -		const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +		const u16 csum_size = fs_info->csum_size;
>  		size_t nblocks;
>  
>  		nblocks = dio_bio->bi_iter.bi_size >> fs_info->sectorsize_bits;
> diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
> index ecc731a6bbae..4d612105b991 100644
> --- a/fs/btrfs/ordered-data.c
> +++ b/fs/btrfs/ordered-data.c
> @@ -868,7 +868,7 @@ int btrfs_find_ordered_sum(struct btrfs_inode *inode, u64 offset,
>  	struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
>  	unsigned long num_sectors;
>  	unsigned long i;
> -	const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +	const u16 csum_size = fs_info->csum_size;
>  	int index = 0;
>  
>  	ordered = btrfs_lookup_ordered_extent(inode, offset);
> diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
> index c3a2325e64a4..4662fd8ca546 100644
> --- a/fs/btrfs/ordered-data.h
> +++ b/fs/btrfs/ordered-data.h
> @@ -137,7 +137,7 @@ static inline int btrfs_ordered_sum_size(struct btrfs_fs_info *fs_info,
>  					 unsigned long bytes)
>  {
>  	int num_sectors = (int)DIV_ROUND_UP(bytes, fs_info->sectorsize);
> -	int csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +	const u16 csum_size = fs_info->csum_size;
>  
>  	return sizeof(struct btrfs_ordered_sum) + num_sectors * csum_size;
>  }
> diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
> index 7babf670c8c2..d4f693a4ca38 100644
> --- a/fs/btrfs/scrub.c
> +++ b/fs/btrfs/scrub.c
> @@ -610,7 +610,7 @@ static noinline_for_stack struct scrub_ctx *scrub_setup_ctx(
>  	atomic_set(&sctx->bios_in_flight, 0);
>  	atomic_set(&sctx->workers_pending, 0);
>  	atomic_set(&sctx->cancel_req, 0);
> -	sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
> +	sctx->csum_size = fs_info->csum_size;
>  
>  	spin_lock_init(&sctx->list_lock);
>  	spin_lock_init(&sctx->stat_lock);
> diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
> index c0e19917e59b..5efaf1f811e2 100644
> --- a/fs/btrfs/tree-checker.c
> +++ b/fs/btrfs/tree-checker.c
> @@ -336,7 +336,7 @@ static int check_csum_item(struct extent_buffer *leaf, struct btrfs_key *key,
>  {
>  	struct btrfs_fs_info *fs_info = leaf->fs_info;
>  	u32 sectorsize = fs_info->sectorsize;
> -	u32 csumsize = btrfs_super_csum_size(fs_info->super_copy);
> +	const u16 csumsize = fs_info->csum_size;
>  
>  	if (key->objectid != BTRFS_EXTENT_CSUM_OBJECTID) {
>  		generic_err(leaf, slot,
>