On Thu, Mar 28, 2013 at 04:11:38PM +0800, Miao Xie wrote:
> bytenr in btrfs_sector_sum is unnecessary, because the extents that
> btrfs_sector_sum points to are continuous，we can find out the expected
> checksums by btrfs_ordered_sum's bytenr and the offset, so we can
> remove btrfs_sector_sum's bytenr.
>
> After removing bytenr, we don't use the while loop to get the checksums
> one by one. Now, we can get several checksum value at one time. By this
> way, the performance of write is improved by ~74% on my SSD (31MB/s -> 54MB/s)
>
> test command:
> # dd if=/dev/zero of=/mnt/btrfs/file0 bs=1M count=1024 oflag=sync
Looks good to me.
Reviewed-by: Liu Bo <bo.li.liu@xxxxxxxxxx>
>
> Signed-off-by: Miao Xie <miaox@xxxxxxxxxxxxxx>
> ---
> fs/btrfs/file-item.c | 144 ++++++++++++++++++------------------------------
> fs/btrfs/ordered-data.c | 21 +++----
> fs/btrfs/ordered-data.h | 25 ++-------
> fs/btrfs/relocation.c | 10 ----
> fs/btrfs/scrub.c | 16 ++----
> 5 files changed, 72 insertions(+), 144 deletions(-)
>
> diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
> index 3e2f080..9a447bc 100644
> --- a/fs/btrfs/file-item.c
> +++ b/fs/btrfs/file-item.c
> @@ -34,8 +34,7 @@
>
> #define MAX_ORDERED_SUM_BYTES(r) ((PAGE_SIZE - \
> sizeof(struct btrfs_ordered_sum)) / \
> - sizeof(struct btrfs_sector_sum) * \
> - (r)->sectorsize - (r)->sectorsize)
> + sizeof(u32) * (r)->sectorsize)
>
> int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
> struct btrfs_root *root,
> @@ -311,7 +310,6 @@ int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
> struct btrfs_path *path;
> struct extent_buffer *leaf;
> struct btrfs_ordered_sum *sums;
> - struct btrfs_sector_sum *sector_sum;
> struct btrfs_csum_item *item;
> LIST_HEAD(tmplist);
> unsigned long offset;
> @@ -385,34 +383,28 @@ int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
> struct btrfs_csum_item);
> while (start < csum_end) {
> size = min_t(size_t, csum_end - start,
> - MAX_ORDERED_SUM_BYTES(root));
> + MAX_ORDERED_SUM_BYTES(root));
> sums = kzalloc(btrfs_ordered_sum_size(root, size),
> - GFP_NOFS);
> + GFP_NOFS);
> if (!sums) {
> ret = -ENOMEM;
> goto fail;
> }
>
> - sector_sum = sums->sums;
> sums->bytenr = start;
> - sums->len = size;
> + sums->len = (int)size;
>
> offset = (start - key.offset) >>
> root->fs_info->sb->s_blocksize_bits;
> offset *= csum_size;
> + size >>= root->fs_info->sb->s_blocksize_bits;
>
> - while (size > 0) {
> - read_extent_buffer(path->nodes[0],
> - §or_sum->sum,
> - ((unsigned long)item) +
> - offset, csum_size);
> - sector_sum->bytenr = start;
> -
> - size -= root->sectorsize;
> - start += root->sectorsize;
> - offset += csum_size;
> - sector_sum++;
> - }
> + read_extent_buffer(path->nodes[0],
> + sums->sums,
> + ((unsigned long)item) + offset,
> + csum_size * size);
> +
> + start += root->sectorsize * size;
> list_add_tail(&sums->list, &tmplist);
> }
> path->slots[0]++;
> @@ -434,23 +426,20 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
> struct bio *bio, u64 file_start, int contig)
> {
> struct btrfs_ordered_sum *sums;
> - struct btrfs_sector_sum *sector_sum;
> struct btrfs_ordered_extent *ordered;
> char *data;
> struct bio_vec *bvec = bio->bi_io_vec;
> int bio_index = 0;
> + int index;
> unsigned long total_bytes = 0;
> unsigned long this_sum_bytes = 0;
> u64 offset;
> - u64 disk_bytenr;
>
> WARN_ON(bio->bi_vcnt <= 0);
> sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
> if (!sums)
> return -ENOMEM;
>
> - sector_sum = sums->sums;
> - disk_bytenr = (u64)bio->bi_sector << 9;
> sums->len = bio->bi_size;
> INIT_LIST_HEAD(&sums->list);
>
> @@ -461,7 +450,8 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
>
> ordered = btrfs_lookup_ordered_extent(inode, offset);
> BUG_ON(!ordered); /* Logic error */
> - sums->bytenr = ordered->start;
> + sums->bytenr = (u64)bio->bi_sector << 9;
> + index = 0;
>
> while (bio_index < bio->bi_vcnt) {
> if (!contig)
> @@ -480,29 +470,28 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
> sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
> GFP_NOFS);
> BUG_ON(!sums); /* -ENOMEM */
> - sector_sum = sums->sums;
> sums->len = bytes_left;
> ordered = btrfs_lookup_ordered_extent(inode, offset);
> BUG_ON(!ordered); /* Logic error */
> - sums->bytenr = ordered->start;
> + sums->bytenr = ((u64)bio->bi_sector << 9) +
> + total_bytes;
> + index = 0;
> }
>
> data = kmap_atomic(bvec->bv_page);
> - sector_sum->sum = ~(u32)0;
> - sector_sum->sum = btrfs_csum_data(root,
> - data + bvec->bv_offset,
> - sector_sum->sum,
> - bvec->bv_len);
> + sums->sums[index] = ~(u32)0;
> + sums->sums[index] = btrfs_csum_data(root,
> + data + bvec->bv_offset,
> + sums->sums[index],
> + bvec->bv_len);
> kunmap_atomic(data);
> - btrfs_csum_final(sector_sum->sum,
> - (char *)§or_sum->sum);
> - sector_sum->bytenr = disk_bytenr;
> + btrfs_csum_final(sums->sums[index],
> + (char *)(sums->sums + index));
>
> - sector_sum++;
> bio_index++;
> + index++;
> total_bytes += bvec->bv_len;
> this_sum_bytes += bvec->bv_len;
> - disk_bytenr += bvec->bv_len;
> offset += bvec->bv_len;
> bvec++;
> }
> @@ -691,63 +680,42 @@ out:
> return ret;
> }
>
> -static u64 btrfs_sector_sum_left(struct btrfs_ordered_sum *sums,
> - struct btrfs_sector_sum *sector_sum,
> - u64 total_bytes, u64 sectorsize)
> -{
> - u64 tmp = sectorsize;
> - u64 next_sector = sector_sum->bytenr;
> - struct btrfs_sector_sum *next = sector_sum + 1;
> -
> - while ((tmp + total_bytes) < sums->len) {
> - if (next_sector + sectorsize != next->bytenr)
> - break;
> - tmp += sectorsize;
> - next_sector = next->bytenr;
> - next++;
> - }
> - return tmp;
> -}
> -
> int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
> struct btrfs_root *root,
> struct btrfs_ordered_sum *sums)
> {
> - u64 bytenr;
> - int ret;
> struct btrfs_key file_key;
> struct btrfs_key found_key;
> - u64 next_offset;
> - u64 total_bytes = 0;
> - int found_next;
> struct btrfs_path *path;
> struct btrfs_csum_item *item;
> struct btrfs_csum_item *item_end;
> struct extent_buffer *leaf = NULL;
> + u64 next_offset;
> + u64 total_bytes = 0;
> u64 csum_offset;
> - struct btrfs_sector_sum *sector_sum;
> + u64 bytenr;
> u32 nritems;
> u32 ins_size;
> + int index = 0;
> + int found_next;
> + int ret;
> u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
>
> path = btrfs_alloc_path();
> if (!path)
> return -ENOMEM;
> -
> - sector_sum = sums->sums;
> again:
> next_offset = (u64)-1;
> found_next = 0;
> + bytenr = sums->bytenr + total_bytes;
> file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
> - file_key.offset = sector_sum->bytenr;
> - bytenr = sector_sum->bytenr;
> + file_key.offset = bytenr;
> btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
>
> - item = btrfs_lookup_csum(trans, root, path, sector_sum->bytenr, 1);
> + item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
> if (!IS_ERR(item)) {
> - leaf = path->nodes[0];
> - ret = 0;
> - goto found;
> + csum_offset = 0;
> + goto csum;
> }
> ret = PTR_ERR(item);
> if (ret != -EFBIG && ret != -ENOENT)
> @@ -826,8 +794,7 @@ again:
>
> free_space = btrfs_leaf_free_space(root, leaf) -
> sizeof(struct btrfs_item) - csum_size;
> - tmp = btrfs_sector_sum_left(sums, sector_sum, total_bytes,
> - root->sectorsize);
> + tmp = sums->len - total_bytes;
> tmp >>= root->fs_info->sb->s_blocksize_bits;
> WARN_ON(tmp < 1);
>
> @@ -850,8 +817,7 @@ insert:
> if (found_next) {
> u64 tmp;
>
> - tmp = btrfs_sector_sum_left(sums, sector_sum, total_bytes,
> - root->sectorsize);
> + tmp = sums->len - total_bytes;
> tmp >>= root->fs_info->sb->s_blocksize_bits;
> tmp = min(tmp, (next_offset - file_key.offset) >>
> root->fs_info->sb->s_blocksize_bits);
> @@ -873,30 +839,26 @@ insert:
> goto fail_unlock;
> }
> csum:
> + ret = 0;
> leaf = path->nodes[0];
> +
> item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
> - ret = 0;
> + item_end = (struct btrfs_csum_item *)((unsigned char *)item +
> + btrfs_item_size_nr(leaf, path->slots[0]));
> item = (struct btrfs_csum_item *)((unsigned char *)item +
> csum_offset * csum_size);
> -found:
> - item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
> - item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
> - btrfs_item_size_nr(leaf, path->slots[0]));
> -next_sector:
>
> - write_extent_buffer(leaf, §or_sum->sum, (unsigned long)item, csum_size);
> -
> - total_bytes += root->sectorsize;
> - sector_sum++;
> - if (total_bytes < sums->len) {
> - item = (struct btrfs_csum_item *)((char *)item +
> - csum_size);
> - if (item < item_end && bytenr + PAGE_CACHE_SIZE ==
> - sector_sum->bytenr) {
> - bytenr = sector_sum->bytenr;
> - goto next_sector;
> - }
> - }
> + ins_size = (u32)(sums->len - total_bytes) >>
> + root->fs_info->sb->s_blocksize_bits;
> + ins_size *= csum_size;
> + ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
> + ins_size);
> + write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
> + ins_size);
> +
> + ins_size /= csum_size;
> + total_bytes += ins_size * root->sectorsize;
> + index += ins_size;
>
> btrfs_mark_buffer_dirty(path->nodes[0]);
> if (total_bytes < sums->len) {
> diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
> index 2b959b6..23bb43a 100644
> --- a/fs/btrfs/ordered-data.c
> +++ b/fs/btrfs/ordered-data.c
> @@ -987,7 +987,6 @@ int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
> u32 *sum, int len)
> {
> struct btrfs_ordered_sum *ordered_sum;
> - struct btrfs_sector_sum *sector_sums;
> struct btrfs_ordered_extent *ordered;
> struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
> unsigned long num_sectors;
> @@ -1004,17 +1003,15 @@ int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
> if (disk_bytenr >= ordered_sum->bytenr &&
> disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
> i = (disk_bytenr - ordered_sum->bytenr) / sectorsize;
> - sector_sums = ordered_sum->sums + i;
> - num_sectors = ordered_sum->len / sectorsize;
> - for (; i < num_sectors; i++) {
> - if (sector_sums[i].bytenr == disk_bytenr) {
> - sum[index] = sector_sums[i].sum;
> - index++;
> - if (index == len)
> - goto out;
> - disk_bytenr += sectorsize;
> - }
> - }
> + num_sectors = ordered_sum->len / sectorsize - i;
> + num_sectors = min_t(int, len - index, num_sectors);
> + memcpy(sum + index, ordered_sum->sums + i,
> + num_sectors);
> +
> + index += (int)num_sectors;
> + if (index == len)
> + goto out;
> + disk_bytenr += num_sectors * sectorsize;
> }
> }
> out:
> diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
> index 58b0e3b..888bcbb 100644
> --- a/fs/btrfs/ordered-data.h
> +++ b/fs/btrfs/ordered-data.h
> @@ -26,18 +26,6 @@ struct btrfs_ordered_inode_tree {
> struct rb_node *last;
> };
>
> -/*
> - * these are used to collect checksums done just before bios submission.
> - * They are attached via a list into the ordered extent, and
> - * checksum items are inserted into the tree after all the blocks in
> - * the ordered extent are on disk
> - */
> -struct btrfs_sector_sum {
> - /* bytenr on disk */
> - u64 bytenr;
> - u32 sum;
> -};
> -
> struct btrfs_ordered_sum {
> /* bytenr is the start of this extent on disk */
> u64 bytenr;
> @@ -45,10 +33,10 @@ struct btrfs_ordered_sum {
> /*
> * this is the length in bytes covered by the sums array below.
> */
> - unsigned long len;
> + int len;
> struct list_head list;
> - /* last field is a variable length array of btrfs_sector_sums */
> - struct btrfs_sector_sum sums[];
> + /* last field is a variable length array of csums */
> + u32 sums[];
> };
>
> /*
> @@ -149,11 +137,8 @@ struct btrfs_ordered_extent {
> static inline int btrfs_ordered_sum_size(struct btrfs_root *root,
> unsigned long bytes)
> {
> - unsigned long num_sectors = (bytes + root->sectorsize - 1) /
> - root->sectorsize;
> - num_sectors++;
> - return sizeof(struct btrfs_ordered_sum) +
> - num_sectors * sizeof(struct btrfs_sector_sum);
> + int num_sectors = (int)DIV_ROUND_UP(bytes, root->sectorsize);
> + return sizeof(struct btrfs_ordered_sum) + num_sectors * sizeof(u32);
> }
>
> static inline void
> diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
> index 3ebe879..5928142 100644
> --- a/fs/btrfs/relocation.c
> +++ b/fs/btrfs/relocation.c
> @@ -4335,10 +4335,8 @@ out:
> int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
> {
> struct btrfs_ordered_sum *sums;
> - struct btrfs_sector_sum *sector_sum;
> struct btrfs_ordered_extent *ordered;
> struct btrfs_root *root = BTRFS_I(inode)->root;
> - size_t offset;
> int ret;
> u64 disk_bytenr;
> LIST_HEAD(list);
> @@ -4356,16 +4354,8 @@ int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
> sums = list_entry(list.next, struct btrfs_ordered_sum, list);
> list_del_init(&sums->list);
>
> - sector_sum = sums->sums;
> sums->bytenr = ordered->start;
>
> - offset = 0;
> - while (offset < sums->len) {
> - sector_sum->bytenr += ordered->start - disk_bytenr;
> - sector_sum++;
> - offset += root->sectorsize;
> - }
> -
> btrfs_add_ordered_sum(inode, ordered, sums);
> }
> out:
> diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
> index 53c3501..6c292b1 100644
> --- a/fs/btrfs/scrub.c
> +++ b/fs/btrfs/scrub.c
> @@ -2128,8 +2128,7 @@ static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u64 len,
> u8 *csum)
> {
> struct btrfs_ordered_sum *sum = NULL;
> - int ret = 0;
> - unsigned long i;
> + unsigned long index;
> unsigned long num_sectors;
>
> while (!list_empty(&sctx->csum_list)) {
> @@ -2148,19 +2147,14 @@ static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u64 len,
> if (!sum)
> return 0;
>
> + index = (logical - sum->bytenr) / sctx->sectorsize;
> num_sectors = sum->len / sctx->sectorsize;
> - for (i = 0; i < num_sectors; ++i) {
> - if (sum->sums[i].bytenr == logical) {
> - memcpy(csum, &sum->sums[i].sum, sctx->csum_size);
> - ret = 1;
> - break;
> - }
> - }
> - if (ret && i == num_sectors - 1) {
> + memcpy(csum, sum->sums + index, sctx->csum_size);
> + if (index == num_sectors - 1) {
> list_del(&sum->list);
> kfree(sum);
> }
> - return ret;
> + return 1;
> }
>
> /* scrub extent tries to collect up to 64 kB for each bio */
> --
> 1.8.0.1
> --
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