From: Omar Sandoval osandov@fb.com
[ Upstream commit e331f6b19f8adde2307588bb325ae5de78617c20 ]
btrfs_csum_one_bio() loops over each filesystem block in the bio while keeping a cursor of its current logical position in the file in order to look up the ordered extent to add the checksums to. However, this doesn't make much sense for compressed extents, as a sector on disk does not correspond to a sector of decompressed file data. It happens to work because:
1) the compressed bio always covers one ordered extent 2) the size of the bio is always less than the size of the ordered extent
However, the second point will not always be true for encoded writes.
Let's add a boolean parameter to btrfs_csum_one_bio() to indicate that it can assume that the bio only covers one ordered extent. Since we're already changing the signature, let's get rid of the contig parameter and make it implied by the offset parameter, similar to the change we recently made to btrfs_lookup_bio_sums(). Additionally, let's rename nr_sectors to blockcount to make it clear that it's the number of filesystem blocks, not the number of 512-byte sectors.
Reviewed-by: Josef Bacik josef@toxicpanda.com Reviewed-by: Nikolay Borisov nborisov@suse.com Signed-off-by: Omar Sandoval osandov@fb.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/btrfs/compression.c | 2 +- fs/btrfs/ctree.h | 2 +- fs/btrfs/file-item.c | 37 +++++++++++++++++-------------------- fs/btrfs/inode.c | 8 ++++---- 4 files changed, 23 insertions(+), 26 deletions(-)
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 32da97c3c19d..b2bb96934a8f 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -590,7 +590,7 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
if (submit) { if (!skip_sum) { - ret = btrfs_csum_one_bio(inode, bio, start, 1); + ret = btrfs_csum_one_bio(inode, bio, start, true); if (ret) goto finish_cb; } diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index cd8e0f9ae82c..f1d357d15b1a 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3179,7 +3179,7 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_ordered_sum *sums); blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio, - u64 file_start, int contig); + u64 offset, bool one_ordered); int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end, struct list_head *list, int search_commit); void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode, diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c index d1cbb64a78f3..8e6ff09f5c36 100644 --- a/fs/btrfs/file-item.c +++ b/fs/btrfs/file-item.c @@ -609,32 +609,33 @@ int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end, return ret; }
-/* - * btrfs_csum_one_bio - Calculates checksums of the data contained inside a bio +/** + * Calculate checksums of the data contained inside a bio + * * @inode: Owner of the data inside the bio * @bio: Contains the data to be checksummed - * @file_start: offset in file this bio begins to describe - * @contig: Boolean. If true/1 means all bio vecs in this bio are - * contiguous and they begin at @file_start in the file. False/0 - * means this bio can contain potentially discontiguous bio vecs - * so the logical offset of each should be calculated separately. + * @offset: If (u64)-1, @bio may contain discontiguous bio vecs, so the + * file offsets are determined from the page offsets in the bio. + * Otherwise, this is the starting file offset of the bio vecs in + * @bio, which must be contiguous. + * @one_ordered: If true, @bio only refers to one ordered extent. */ blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio, - u64 file_start, int contig) + u64 offset, bool one_ordered) { struct btrfs_fs_info *fs_info = inode->root->fs_info; SHASH_DESC_ON_STACK(shash, fs_info->csum_shash); struct btrfs_ordered_sum *sums; struct btrfs_ordered_extent *ordered = NULL; + const bool use_page_offsets = (offset == (u64)-1); char *data; struct bvec_iter iter; struct bio_vec bvec; int index; - int nr_sectors; + unsigned int blockcount; unsigned long total_bytes = 0; unsigned long this_sum_bytes = 0; int i; - u64 offset; unsigned nofs_flag;
nofs_flag = memalloc_nofs_save(); @@ -648,18 +649,13 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio, sums->len = bio->bi_iter.bi_size; INIT_LIST_HEAD(&sums->list);
- if (contig) - offset = file_start; - else - offset = 0; /* shut up gcc */ - sums->bytenr = bio->bi_iter.bi_sector << 9; index = 0;
shash->tfm = fs_info->csum_shash;
bio_for_each_segment(bvec, bio, iter) { - if (!contig) + if (use_page_offsets) offset = page_offset(bvec.bv_page) + bvec.bv_offset;
if (!ordered) { @@ -678,13 +674,14 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio, } }
- nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, + blockcount = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len + fs_info->sectorsize - 1);
- for (i = 0; i < nr_sectors; i++) { - if (offset >= ordered->file_offset + ordered->num_bytes || - offset < ordered->file_offset) { + for (i = 0; i < blockcount; i++) { + if (!one_ordered && + !in_range(offset, ordered->file_offset, + ordered->num_bytes)) { unsigned long bytes_left;
sums->len = this_sum_bytes; diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index cc957cce23a1..6680e74b1977 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -2308,7 +2308,7 @@ void btrfs_clear_delalloc_extent(struct inode *vfs_inode, static blk_status_t btrfs_submit_bio_start(struct inode *inode, struct bio *bio, u64 dio_file_offset) { - return btrfs_csum_one_bio(BTRFS_I(inode), bio, 0, 0); + return btrfs_csum_one_bio(BTRFS_I(inode), bio, (u64)-1, false); }
/* @@ -2560,7 +2560,7 @@ blk_status_t btrfs_submit_data_bio(struct inode *inode, struct bio *bio, 0, btrfs_submit_bio_start); goto out; } else if (!skip_sum) { - ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, 0, 0); + ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, (u64)-1, false); if (ret) goto out; } @@ -8196,7 +8196,7 @@ static blk_status_t btrfs_submit_bio_start_direct_io(struct inode *inode, struct bio *bio, u64 dio_file_offset) { - return btrfs_csum_one_bio(BTRFS_I(inode), bio, dio_file_offset, 1); + return btrfs_csum_one_bio(BTRFS_I(inode), bio, dio_file_offset, false); }
static void btrfs_end_dio_bio(struct bio *bio) @@ -8253,7 +8253,7 @@ static inline blk_status_t btrfs_submit_dio_bio(struct bio *bio, * If we aren't doing async submit, calculate the csum of the * bio now. */ - ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, file_offset, 1); + ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, file_offset, false); if (ret) goto err; } else {