From 3edf7d33f4edb1e4a9bb0a4c0a84d95fb4d22a09 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Fri, 18 Jul 2008 06:17:13 -0400 Subject: Btrfs: Handle data checksumming on bios that span multiple ordered extents Data checksumming is done right before the bio is sent down the IO stack, which means a single bio might span more than one ordered extent. In this case, the checksumming data is split between two ordered extents. Signed-off-by: Chris Mason --- fs/btrfs/file-item.c | 43 +++++++++++++++++++++++++++++++++++++++---- 1 file changed, 39 insertions(+), 4 deletions(-) (limited to 'fs/btrfs/file-item.c') diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c index 345caf8ff51..e02f1e5acb0 100644 --- a/fs/btrfs/file-item.c +++ b/fs/btrfs/file-item.c @@ -134,26 +134,53 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, return ret; } -int btrfs_csum_one_bio(struct btrfs_root *root, - struct bio *bio, struct btrfs_ordered_sum **sums_ret) +int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode, + struct bio *bio) { 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; + unsigned long total_bytes = 0; + unsigned long this_sum_bytes = 0; + u64 offset; WARN_ON(bio->bi_vcnt <= 0); sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS); if (!sums) return -ENOMEM; - *sums_ret = sums; + sector_sum = &sums->sums; - sums->file_offset = page_offset(bvec->bv_page); + sums->file_offset = page_offset(bvec->bv_page) + bvec->bv_offset; sums->len = bio->bi_size; INIT_LIST_HEAD(&sums->list); + ordered = btrfs_lookup_ordered_extent(inode, sums->file_offset); + BUG_ON(!ordered); while(bio_index < bio->bi_vcnt) { + offset = page_offset(bvec->bv_page) + bvec->bv_offset; + if (offset >= ordered->file_offset + ordered->len) { + unsigned long bytes_left; + sums->len = this_sum_bytes; + this_sum_bytes = 0; + btrfs_add_ordered_sum(inode, ordered, sums); + btrfs_put_ordered_extent(ordered); + + bytes_left = bio->bi_size - total_bytes; + + sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left), + GFP_NOFS); + BUG_ON(!sums); + sector_sum = &sums->sums; + sums->len = bytes_left; + sums->file_offset = offset; + ordered = btrfs_lookup_ordered_extent(inode, + sums->file_offset); + BUG_ON(!ordered); + } + data = kmap_atomic(bvec->bv_page, KM_USER0); sector_sum->sum = ~(u32)0; sector_sum->sum = btrfs_csum_data(root, @@ -165,10 +192,18 @@ int btrfs_csum_one_bio(struct btrfs_root *root, (char *)§or_sum->sum); sector_sum->offset = page_offset(bvec->bv_page) + bvec->bv_offset; + sector_sum++; bio_index++; + total_bytes += bvec->bv_len; + this_sum_bytes += bvec->bv_len; bvec++; } + btrfs_add_ordered_sum(inode, ordered, sums); + btrfs_put_ordered_extent(ordered); + if (total_bytes != bio->bi_size) { +printk("warning, total bytes %lu bio size %u\n", total_bytes, bio->bi_size); + } return 0; } -- cgit v1.2.3