On Friday 07 Aug 2015 14:30:21 Josef Bacik wrote:
> On 08/07/2015 03:05 AM, Chandan Rajendra wrote:
> > Checksums are applicable to sectorsize units. The current code uses
> > bio->bv_len units to compute and look up checksums. This works on machines
> > where sectorsize == PAGE_SIZE. This patch makes the checksum computation
> > and look up code to work with sectorsize units.
> >
> > Reviewed-by: Liu Bo <bo.li....@oracle.com>
> > Signed-off-by: Chandan Rajendra <chan...@linux.vnet.ibm.com>
> > ---
> >
> > fs/btrfs/file-item.c | 90
> > +++++++++++++++++++++++++++++++++------------------- 1 file changed, 57
> > insertions(+), 33 deletions(-)
> >
> > diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
> > index 58ece65..d752051 100644
> > --- a/fs/btrfs/file-item.c
> > +++ b/fs/btrfs/file-item.c
> > @@ -172,6 +172,7 @@ static int __btrfs_lookup_bio_sums(struct btrfs_root
> > *root,>
> > u64 item_start_offset = 0;
> > u64 item_last_offset = 0;
> > u64 disk_bytenr;
> >
> > + u64 page_bytes_left;
> >
> > u32 diff;
> > int nblocks;
> > int bio_index = 0;
> >
> > @@ -220,6 +221,8 @@ static int __btrfs_lookup_bio_sums(struct btrfs_root
> > *root,>
> > disk_bytenr = (u64)bio->bi_iter.bi_sector << 9;
> > if (dio)
> >
> > offset = logical_offset;
> >
> > +
> > + page_bytes_left = bvec->bv_len;
> >
> > while (bio_index < bio->bi_vcnt) {
> >
> > if (!dio)
> >
> > offset = page_offset(bvec->bv_page) + bvec->bv_offset;
> >
> > @@ -243,7 +246,7 @@ static int __btrfs_lookup_bio_sums(struct btrfs_root
> > *root,>
> > if (BTRFS_I(inode)->root->root_key.objectid ==
> >
> > BTRFS_DATA_RELOC_TREE_OBJECTID) {
> >
> > set_extent_bits(io_tree, offset,
> >
> > - offset + bvec->bv_len - 1,
> > + offset + root->sectorsize - 1,
> >
> > EXTENT_NODATASUM, GFP_NOFS);
> >
> > } else {
> >
> > btrfs_info(BTRFS_I(inode)->root-
>fs_info,
> >
> > @@ -281,11 +284,17 @@ static int __btrfs_lookup_bio_sums(struct btrfs_root
> > *root,>
> > found:
> > csum += count * csum_size;
> > nblocks -= count;
> >
> > - bio_index += count;
> > +
> >
> > while (count--) {
> >
> > - disk_bytenr += bvec->bv_len;
> > - offset += bvec->bv_len;
> > - bvec++;
> > + disk_bytenr += root->sectorsize;
> > + offset += root->sectorsize;
> > + page_bytes_left -= root->sectorsize;
> > + if (!page_bytes_left) {
> > + bio_index++;
> > + bvec++;
> > + page_bytes_left = bvec->bv_len;
> > + }
> > +
> >
> > }
> >
> > }
> > btrfs_free_path(path);
> >
> > @@ -432,6 +441,8 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct
> > inode *inode,>
> > struct bio_vec *bvec = bio->bi_io_vec;
> > int bio_index = 0;
> > int index;
> >
> > + int nr_sectors;
> > + int i;
> >
> > unsigned long total_bytes = 0;
> > unsigned long this_sum_bytes = 0;
> > u64 offset;
> >
> > @@ -459,41 +470,54 @@ int btrfs_csum_one_bio(struct btrfs_root *root,
> > struct inode *inode,>
> > if (!contig)
> >
> > offset = page_offset(bvec->bv_page) + bvec->bv_offset;
> >
> > - if (offset >= ordered->file_offset + ordered->len ||
> > - offset < ordered->file_offset) {
> > - 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);
> > + data = kmap_atomic(bvec->bv_page);
>
> I don't think we can have something kmap_atomic()'ed and then do
> allocations under it right? That's why we only kmap_atomic(), do the
> copy, and then unmap, unless I'm forgetting something? Thanks,
>
Josef, you are correct. I will fix it and send out version V3 of the patchset
soon. Thanks for the review.
--
chandan
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