Btrfs_record_file_extent() has some small problems like:
1) Can't handle overlap extent
2) May create extent larger than BTRFS_MAX_EXTENT_SIZE
So enhance it using previous added facilites.
This is used for later btrfs-convert, as for new convert, we create save
image first, then copy inode.
Which will also cause extent overlap.
Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com>
---
ctree.h | 1 +
extent-tree.c | 165 ++++++++++++++++++++++++++++++++++++++++------------------
2 files changed, 115 insertions(+), 51 deletions(-)
diff --git a/ctree.h b/ctree.h
index f97af7e..6e3e919 100644
--- a/ctree.h
+++ b/ctree.h
@@ -570,6 +570,7 @@ struct btrfs_extent_item_v0 {
#define BTRFS_MAX_EXTENT_ITEM_SIZE(r) ((BTRFS_LEAF_DATA_SIZE(r) >> 4) - \
sizeof(struct btrfs_item))
+#define BTRFS_MAX_EXTENT_SIZE (128 * 1024 * 1024)
#define BTRFS_EXTENT_FLAG_DATA (1ULL << 0)
#define BTRFS_EXTENT_FLAG_TREE_BLOCK (1ULL << 1)
diff --git a/extent-tree.c b/extent-tree.c
index 9bd99a4..bfc9060 100644
--- a/extent-tree.c
+++ b/extent-tree.c
@@ -3971,16 +3971,11 @@ next:
return 0;
}
-/*
- * Record a file extent. Do all the required works, such as inserting
- * file extent item, inserting extent item and backref item into extent
- * tree and updating block accounting.
- */
-int btrfs_record_file_extent(struct btrfs_trans_handle *trans,
- struct btrfs_root *root, u64 objectid,
- struct btrfs_inode_item *inode,
- u64 file_pos, u64 disk_bytenr,
- u64 num_bytes)
+static int __btrfs_record_file_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 objectid,
+ struct btrfs_inode_item *inode,
+ u64 file_pos, u64 disk_bytenr,
+ u64 *ret_num_bytes)
{
int ret;
struct btrfs_fs_info *info = root->fs_info;
@@ -3988,10 +3983,19 @@ int btrfs_record_file_extent(struct btrfs_trans_handle
*trans,
struct extent_buffer *leaf;
struct btrfs_file_extent_item *fi;
struct btrfs_key ins_key;
- struct btrfs_path path;
+ struct btrfs_path *path;
struct btrfs_extent_item *ei;
u64 nbytes;
+ u64 extent_num_bytes;
+ u64 extent_bytenr;
+ u64 extent_offset;
+ u64 num_bytes = *ret_num_bytes;
+ num_bytes = min_t(u64, num_bytes, BTRFS_MAX_EXTENT_SIZE);
+ /*
+ * All supported file system should not use its 0 extent.
+ * As it's for hole
+ */
if (disk_bytenr == 0) {
ret = btrfs_insert_file_extent(trans, root, objectid,
file_pos, disk_bytenr,
@@ -3999,25 +4003,80 @@ int btrfs_record_file_extent(struct btrfs_trans_handle
*trans,
return ret;
}
- btrfs_init_path(&path);
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ /* First to check extent overlap */
+ ret = btrfs_search_overlap_extent(extent_root, path, disk_bytenr,
+ num_bytes);
+ if (ret < 0)
+ goto fail;
+ if (ret > 0) {
+ /* Found overlap */
+ u64 cur_start;
+ u64 cur_len;
+
+ __get_extent_size(extent_root, path, &cur_start, &cur_len);
+ /*
+ * For convert case, this extent should be a subset of
+ * existing one.
+ */
+ BUG_ON(disk_bytenr < cur_start);
+ extent_bytenr = cur_start;
+ extent_num_bytes = cur_len;
+ extent_offset = disk_bytenr - extent_bytenr;
+ } else {
+ /* No overlap, create new extent */
+ btrfs_release_path(path);
+ ins_key.objectid = disk_bytenr;
+ ins_key.offset = num_bytes;
+ ins_key.type = BTRFS_EXTENT_ITEM_KEY;
+
+ ret = btrfs_insert_empty_item(trans, extent_root, path,
+ &ins_key, sizeof(*ei));
+ if (ret == 0) {
+ leaf = path->nodes[0];
+ ei = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_item);
+
+ btrfs_set_extent_refs(leaf, ei, 0);
+ btrfs_set_extent_generation(leaf, ei, 0);
+ btrfs_set_extent_flags(leaf, ei,
+ BTRFS_EXTENT_FLAG_DATA);
+ btrfs_mark_buffer_dirty(leaf);
+
+ ret = btrfs_update_block_group(trans, root, disk_bytenr,
+ num_bytes, 1, 0);
+ if (ret)
+ goto fail;
+ } else if (ret != -EEXIST) {
+ goto fail;
+ }
+ btrfs_extent_post_op(trans, extent_root);
+ extent_bytenr = disk_bytenr;
+ extent_num_bytes = num_bytes;
+ extent_offset = 0;
+ }
+ btrfs_release_path(path);
ins_key.objectid = objectid;
ins_key.offset = file_pos;
btrfs_set_key_type(&ins_key, BTRFS_EXTENT_DATA_KEY);
- ret = btrfs_insert_empty_item(trans, root, &path, &ins_key,
+ ret = btrfs_insert_empty_item(trans, root, path, &ins_key,
sizeof(*fi));
if (ret)
goto fail;
- leaf = path.nodes[0];
- fi = btrfs_item_ptr(leaf, path.slots[0],
+ leaf = path->nodes[0];
+ fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, fi, trans->transid);
btrfs_set_file_extent_type(leaf, fi, BTRFS_FILE_EXTENT_REG);
- btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
- btrfs_set_file_extent_disk_num_bytes(leaf, fi, num_bytes);
- btrfs_set_file_extent_offset(leaf, fi, 0);
+ btrfs_set_file_extent_disk_bytenr(leaf, fi, extent_bytenr);
+ btrfs_set_file_extent_disk_num_bytes(leaf, fi, extent_num_bytes);
+ btrfs_set_file_extent_offset(leaf, fi, extent_offset);
btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
- btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
+ btrfs_set_file_extent_ram_bytes(leaf, fi, extent_num_bytes);
btrfs_set_file_extent_compression(leaf, fi, 0);
btrfs_set_file_extent_encryption(leaf, fi, 0);
btrfs_set_file_extent_other_encoding(leaf, fi, 0);
@@ -4025,42 +4084,46 @@ int btrfs_record_file_extent(struct btrfs_trans_handle
*trans,
nbytes = btrfs_stack_inode_nbytes(inode) + num_bytes;
btrfs_set_stack_inode_nbytes(inode, nbytes);
+ btrfs_release_path(path);
- btrfs_release_path(&path);
-
- ins_key.objectid = disk_bytenr;
- ins_key.offset = num_bytes;
- ins_key.type = BTRFS_EXTENT_ITEM_KEY;
-
- ret = btrfs_insert_empty_item(trans, extent_root, &path,
- &ins_key, sizeof(*ei));
- if (ret == 0) {
- leaf = path.nodes[0];
- ei = btrfs_item_ptr(leaf, path.slots[0],
- struct btrfs_extent_item);
-
- btrfs_set_extent_refs(leaf, ei, 0);
- btrfs_set_extent_generation(leaf, ei, 0);
- btrfs_set_extent_flags(leaf, ei, BTRFS_EXTENT_FLAG_DATA);
-
- btrfs_mark_buffer_dirty(leaf);
-
- ret = btrfs_update_block_group(trans, root, disk_bytenr,
- num_bytes, 1, 0);
- if (ret)
- goto fail;
- } else if (ret != -EEXIST) {
- goto fail;
- }
- btrfs_extent_post_op(trans, extent_root);
-
- ret = btrfs_inc_extent_ref(trans, root, disk_bytenr, num_bytes, 0,
- root->root_key.objectid,
- objectid, file_pos);
+ ret = btrfs_inc_extent_ref(trans, root, extent_bytenr, extent_num_bytes,
+ 0, root->root_key.objectid, objectid,
+ file_pos - extent_offset);
if (ret)
goto fail;
ret = 0;
+ *ret_num_bytes = min(extent_num_bytes - extent_offset, num_bytes);
fail:
- btrfs_release_path(&path);
+ btrfs_release_path(path);
+ return ret;
+}
+
+/*
+ * Record a file extent. Do all the required works, such as inserting
+ * file extent item, inserting extent item and backref item into extent
+ * tree and updating block accounting.
+ */
+int btrfs_record_file_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 objectid,
+ struct btrfs_inode_item *inode,
+ u64 file_pos, u64 disk_bytenr,
+ u64 num_bytes)
+{
+ u64 cur_disk_bytenr = disk_bytenr;
+ u64 cur_file_pos = file_pos;
+ u64 cur_num_bytes = num_bytes;
+ int ret = 0;
+
+ while (num_bytes > 0) {
+ ret = __btrfs_record_file_extent(trans, root, objectid,
+ inode, cur_file_pos,
+ cur_disk_bytenr,
+ &cur_num_bytes);
+ if (ret < 0)
+ break;
+ cur_disk_bytenr += cur_num_bytes;
+ cur_file_pos += cur_num_bytes;
+ num_bytes -= cur_num_bytes;
+ }
return ret;
}
--
2.6.2
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