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.liu@xxxxxxxxxx>
Signed-off-by: Chandan Rajendra <chandan@xxxxxxxxxxxxxxxxxx>
---
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
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