On 09/30/2015 06:28 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>
Reviewed-by: Josef Bacik <jbacik@xxxxxx>
Signed-off-by: Chandan Rajendra <chandan@xxxxxxxxxxxxxxxxxx>
---
fs/btrfs/file-item.c | 93 +++++++++++++++++++++++++++++++++-------------------
1 file changed, 59 insertions(+), 34 deletions(-)
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 58ece65..818c859 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;
@@ -451,7 +462,7 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
offset = page_offset(bvec->bv_page) + bvec->bv_offset;
ordered = btrfs_lookup_ordered_extent(inode, offset);
- BUG_ON(!ordered); /* Logic error */
+ ASSERT(ordered); /* Logic error */
sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;
index = 0;
@@ -459,41 +470,55 @@ 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);
- bytes_left = bio->bi_iter.bi_size - total_bytes;
+ nr_sectors = (bvec->bv_len + root->sectorsize - 1)
+ >> inode->i_blkbits;
+
+ for (i = 0; i < nr_sectors; i++) {
+ if (offset >= ordered->file_offset + ordered->len ||
+ offset < ordered->file_offset) {
+ unsigned long bytes_left;
+
+ kunmap_atomic(data);
+ 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_iter.bi_size - total_bytes;
+
+ sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
+ GFP_NOFS);
+ BUG_ON(!sums); /* -ENOMEM */
+ sums->len = bytes_left;
+ ordered = btrfs_lookup_ordered_extent(inode,
+ offset);
+ ASSERT(ordered); /* Logic error */
+ sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9)
+ + total_bytes;
+ index = 0;
+
+ data = kmap_atomic(bvec->bv_page);
+ }
- sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
- GFP_NOFS);
- BUG_ON(!sums); /* -ENOMEM */
- sums->len = bytes_left;
- ordered = btrfs_lookup_ordered_extent(inode, offset);
- BUG_ON(!ordered); /* Logic error */
- sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9) +
- total_bytes;
- index = 0;
+ sums->sums[index] = ~(u32)0;
+ sums->sums[index]
+ = btrfs_csum_data(data + bvec->bv_offset
+ + (i * root->sectorsize),
+ sums->sums[index],
+ root->sectorsize);
+ btrfs_csum_final(sums->sums[index],
+ (char *)(sums->sums + index));
+ index++;
+ offset += root->sectorsize;
+ this_sum_bytes += root->sectorsize;
+ total_bytes += root->sectorsize;
}
What I said about this area in the other email I sent just ignore, I
misread the patch. The other stuff is still valid tho. Thanks,
Josef
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