return btrfs_csum_one_bio(BTRFS_I(inode), bio, 0, 0);
}
+/*
+ * Split an extent_map at [start, start + len]
+ *
+ * This function is intended to be used only for extract_ordered_extent().
+ */
+static int split_zoned_em(struct btrfs_inode *inode, u64 start, u64 len,
+ u64 pre, u64 post)
+{
+ struct extent_map_tree *em_tree = &inode->extent_tree;
+ struct extent_map *em;
+ struct extent_map *split_pre = NULL;
+ struct extent_map *split_mid = NULL;
+ struct extent_map *split_post = NULL;
+ int ret = 0;
+ int modified;
+ unsigned long flags;
+
+ /* Sanity check */
+ if (pre == 0 && post == 0)
+ return 0;
+
+ split_pre = alloc_extent_map();
+ if (pre)
+ split_mid = alloc_extent_map();
+ if (post)
+ split_post = alloc_extent_map();
+ if (!split_pre || (pre && !split_mid) || (post && !split_post)) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ASSERT(pre + post < len);
+
+ lock_extent(&inode->io_tree, start, start + len - 1);
+ write_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, start, len);
+ if (!em) {
+ ret = -EIO;
+ goto out_unlock;
+ }
+
+ ASSERT(em->len == len);
+ ASSERT(!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags));
+ ASSERT(em->block_start < EXTENT_MAP_LAST_BYTE);
+
+ flags = em->flags;
+ clear_bit(EXTENT_FLAG_PINNED, &em->flags);
+ clear_bit(EXTENT_FLAG_LOGGING, &flags);
+ modified = !list_empty(&em->list);
+
+ /* First, replace the em with a new extent_map starting from * em->start */
+ split_pre->start = em->start;
+ split_pre->len = (pre ? pre : em->len - post);
+ split_pre->orig_start = split_pre->start;
+ split_pre->block_start = em->block_start;
+ split_pre->block_len = split_pre->len;
+ split_pre->orig_block_len = split_pre->block_len;
+ split_pre->ram_bytes = split_pre->len;
+ split_pre->flags = flags;
+ split_pre->compress_type = em->compress_type;
+ split_pre->generation = em->generation;
+
+ replace_extent_mapping(em_tree, em, split_pre, modified);
+
+ /*
+ * Now we only have an extent_map at:
+ * [em->start, em->start + pre] if pre != 0
+ * [em->start, em->start + em->len - post] if pre == 0
+ */
+
+ if (pre) {
+ /* Insert the middle extent_map */
+ split_mid->start = em->start + pre;
+ split_mid->len = em->len - pre - post;
+ split_mid->orig_start = split_mid->start;
+ split_mid->block_start = em->block_start + pre;
+ split_mid->block_len = split_mid->len;
+ split_mid->orig_block_len = split_mid->block_len;
+ split_mid->ram_bytes = split_mid->len;
+ split_mid->flags = flags;
+ split_mid->compress_type = em->compress_type;
+ split_mid->generation = em->generation;
+ add_extent_mapping(em_tree, split_mid, modified);
+ }
+
+ if (post) {
+ split_post->start = em->start + em->len - post;
+ split_post->len = post;
+ split_post->orig_start = split_post->start;
+ split_post->block_start = em->block_start + em->len - post;
+ split_post->block_len = split_post->len;
+ split_post->orig_block_len = split_post->block_len;
+ split_post->ram_bytes = split_post->len;
+ split_post->flags = flags;
+ split_post->compress_type = em->compress_type;
+ split_post->generation = em->generation;
+ add_extent_mapping(em_tree, split_post, modified);
+ }
+
+ /* Once for us */
+ free_extent_map(em);
+ /* Once for the tree */
+ free_extent_map(em);
+
+out_unlock:
+ write_unlock(&em_tree->lock);
+ unlock_extent(&inode->io_tree, start, start + len - 1);
+out:
+ free_extent_map(split_pre);
+ free_extent_map(split_mid);
+ free_extent_map(split_post);
+
+ return ret;
+}
+
static blk_status_t extract_ordered_extent(struct btrfs_inode *inode,
struct bio *bio, loff_t file_offset)
{
struct btrfs_ordered_extent *ordered;
- struct extent_map *em = NULL, *em_new = NULL;
- struct extent_map_tree *em_tree = &inode->extent_tree;
u64 start = (u64)bio->bi_iter.bi_sector << SECTOR_SHIFT;
+ u64 file_len;
u64 len = bio->bi_iter.bi_size;
u64 end = start + len;
u64 ordered_end;
goto out;
}
+ file_len = ordered->num_bytes;
pre = start - ordered->disk_bytenr;
post = ordered_end - end;
ret = btrfs_split_ordered_extent(ordered, pre, post);
if (ret)
goto out;
-
- read_lock(&em_tree->lock);
- em = lookup_extent_mapping(em_tree, ordered->file_offset, len);
- if (!em) {
- read_unlock(&em_tree->lock);
- ret = -EIO;
- goto out;
- }
- read_unlock(&em_tree->lock);
-
- ASSERT(!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags));
- /*
- * We cannot reuse em_new here but have to create a new one, as
- * unpin_extent_cache() expects the start of the extent map to be the
- * logical offset of the file, which does not hold true anymore after
- * splitting.
- */
- em_new = create_io_em(inode, em->start + pre, len,
- em->start + pre, em->block_start + pre, len,
- len, len, BTRFS_COMPRESS_NONE,
- BTRFS_ORDERED_REGULAR);
- if (IS_ERR(em_new)) {
- ret = PTR_ERR(em_new);
- goto out;
- }
- free_extent_map(em_new);
+ ret = split_zoned_em(inode, file_offset, file_len, pre, post);
out:
- free_extent_map(em);
btrfs_put_ordered_extent(ordered);
return errno_to_blk_status(ret);