From e015640f9c4fa2417dcc3bbbb3b2b61ad4059ab0 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Wed, 16 Apr 2008 11:15:20 -0400 Subject: Btrfs: Write bio checksumming outside the FS mutex This significantly improves streaming write performance by allowing concurrency in the data checksumming. Signed-off-by: Chris Mason --- fs/btrfs/file-item.c | 46 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 32 insertions(+), 14 deletions(-) (limited to 'fs/btrfs/file-item.c') diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c index 374d0245b29d..9259aece6ed1 100644 --- a/fs/btrfs/file-item.c +++ b/fs/btrfs/file-item.c @@ -134,9 +134,36 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, return ret; } +int btrfs_csum_one_bio(struct btrfs_root *root, + struct bio *bio, char **sums_ret) +{ + u32 *sums; + char *data; + struct bio_vec *bvec = bio->bi_io_vec; + int bio_index = 0; + + sums = kmalloc(bio->bi_vcnt * BTRFS_CRC32_SIZE, GFP_NOFS); + if (!sums) + return -ENOMEM; + *sums_ret = (char *)sums; + + while(bio_index < bio->bi_vcnt) { + data = kmap_atomic(bvec->bv_page, KM_USER0); + *sums = ~(u32)0; + *sums = btrfs_csum_data(root, data + bvec->bv_offset, + *sums, bvec->bv_len); + kunmap_atomic(data, KM_USER0); + btrfs_csum_final(*sums, (char *)sums); + sums++; + bio_index++; + bvec++; + } + return 0; +} + int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *inode, - struct bio *bio) + struct bio *bio, char *sums) { u64 objectid = inode->i_ino; u64 offset; @@ -150,12 +177,11 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans, struct btrfs_csum_item *item_end; struct extent_buffer *leaf = NULL; u64 csum_offset; - u32 csum_result; + u32 *sums32 = (u32 *)sums; u32 nritems; u32 ins_size; int bio_index = 0; struct bio_vec *bvec = bio->bi_io_vec; - char *data; char *eb_map; char *eb_token; unsigned long map_len; @@ -278,15 +304,6 @@ found: btrfs_item_size_nr(leaf, path->slots[0])); eb_token = NULL; next_bvec: - data = kmap_atomic(bvec->bv_page, KM_USER0); - csum_result = ~(u32)0; - csum_result = btrfs_csum_data(root, data + bvec->bv_offset, - csum_result, bvec->bv_len); - kunmap_atomic(data, KM_USER0); - btrfs_csum_final(csum_result, (char *)&csum_result); - if (csum_result == 0) { - printk("csum result is 0 for inode %lu offset %Lu\n", inode->i_ino, offset); - } if (!eb_token || (unsigned long)item + BTRFS_CRC32_SIZE >= map_start + map_len) { @@ -304,13 +321,14 @@ next_bvec: } if (eb_token) { memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)), - &csum_result, BTRFS_CRC32_SIZE); + sums32, BTRFS_CRC32_SIZE); } else { - write_extent_buffer(leaf, &csum_result, (unsigned long)item, + write_extent_buffer(leaf, sums32, (unsigned long)item, BTRFS_CRC32_SIZE); } bio_index++; bvec++; + sums32++; if (bio_index < bio->bi_vcnt) { item = (struct btrfs_csum_item *)((char *)item + BTRFS_CRC32_SIZE); -- cgit v1.2.3-55-g7522