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author | Chris Mason <chris.mason@oracle.com> | 2008-04-16 11:15:20 -0400 |
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committer | Chris Mason <chris.mason@oracle.com> | 2008-09-25 11:04:01 -0400 |
commit | e015640f9c4fa2417dcc3bbbb3b2b61ad4059ab0 (patch) | |
tree | 2ba41617e428f60ff970abc8a862ab77980b4a20 /fs/btrfs/file-item.c | |
parent | 44b8bd7edda4f63de180d0f7325c9fb704b3806b (diff) | |
download | op-kernel-dev-e015640f9c4fa2417dcc3bbbb3b2b61ad4059ab0.zip op-kernel-dev-e015640f9c4fa2417dcc3bbbb3b2b61ad4059ab0.tar.gz |
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 <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/file-item.c')
-rw-r--r-- | fs/btrfs/file-item.c | 46 |
1 files changed, 32 insertions, 14 deletions
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c index 374d024..9259aec 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); |