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-rw-r--r--fs/btrfs/ctree.c198
-rw-r--r--fs/btrfs/ctree.h4
2 files changed, 143 insertions, 59 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index ec96f3a6d536..9d4ba3470c17 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -37,6 +37,11 @@ static int balance_node_right(struct btrfs_trans_handle *trans,
struct extent_buffer *src_buf);
static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct btrfs_path *path, int level, int slot);
+static int setup_items_for_insert(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_path *path,
+ struct btrfs_key *cpu_key, u32 *data_size,
+ u32 total_data, u32 total_size, int nr);
+
struct btrfs_path *btrfs_alloc_path(void)
{
@@ -2997,75 +3002,85 @@ again:
return ret;
}
-/*
- * This function splits a single item into two items,
- * giving 'new_key' to the new item and splitting the
- * old one at split_offset (from the start of the item).
- *
- * The path may be released by this operation. After
- * the split, the path is pointing to the old item. The
- * new item is going to be in the same node as the old one.
- *
- * Note, the item being split must be smaller enough to live alone on
- * a tree block with room for one extra struct btrfs_item
- *
- * This allows us to split the item in place, keeping a lock on the
- * leaf the entire time.
- */
-int btrfs_split_item(struct btrfs_trans_handle *trans,
- struct btrfs_root *root,
- struct btrfs_path *path,
- struct btrfs_key *new_key,
- unsigned long split_offset)
+static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, int ins_len)
{
- u32 item_size;
+ struct btrfs_key key;
struct extent_buffer *leaf;
- struct btrfs_key orig_key;
- struct btrfs_item *item;
- struct btrfs_item *new_item;
- int ret = 0;
- int slot;
- u32 nritems;
- u32 orig_offset;
- struct btrfs_disk_key disk_key;
- char *buf;
+ struct btrfs_file_extent_item *fi;
+ u64 extent_len = 0;
+ u32 item_size;
+ int ret;
leaf = path->nodes[0];
- btrfs_item_key_to_cpu(leaf, &orig_key, path->slots[0]);
- if (btrfs_leaf_free_space(root, leaf) >= sizeof(struct btrfs_item))
- goto split;
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+
+ BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY &&
+ key.type != BTRFS_EXTENT_CSUM_KEY);
+
+ if (btrfs_leaf_free_space(root, leaf) >= ins_len)
+ return 0;
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+ if (key.type == BTRFS_EXTENT_DATA_KEY) {
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ extent_len = btrfs_file_extent_num_bytes(leaf, fi);
+ }
btrfs_release_path(root, path);
- path->search_for_split = 1;
path->keep_locks = 1;
-
- ret = btrfs_search_slot(trans, root, &orig_key, path, 0, 1);
+ path->search_for_split = 1;
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
path->search_for_split = 0;
+ if (ret < 0)
+ goto err;
+ ret = -EAGAIN;
+ leaf = path->nodes[0];
/* if our item isn't there or got smaller, return now */
- if (ret != 0 || item_size != btrfs_item_size_nr(path->nodes[0],
- path->slots[0])) {
- path->keep_locks = 0;
- return -EAGAIN;
+ if (ret > 0 || item_size != btrfs_item_size_nr(leaf, path->slots[0]))
+ goto err;
+
+ if (key.type == BTRFS_EXTENT_DATA_KEY) {
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ if (extent_len != btrfs_file_extent_num_bytes(leaf, fi))
+ goto err;
}
btrfs_set_path_blocking(path);
- ret = split_leaf(trans, root, &orig_key, path,
- sizeof(struct btrfs_item), 1);
- path->keep_locks = 0;
+ ret = split_leaf(trans, root, &key, path, ins_len, 1);
BUG_ON(ret);
+ path->keep_locks = 0;
btrfs_unlock_up_safe(path, 1);
+ return 0;
+err:
+ path->keep_locks = 0;
+ return ret;
+}
+
+static noinline int split_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_key *new_key,
+ unsigned long split_offset)
+{
+ struct extent_buffer *leaf;
+ struct btrfs_item *item;
+ struct btrfs_item *new_item;
+ int slot;
+ char *buf;
+ u32 nritems;
+ u32 item_size;
+ u32 orig_offset;
+ struct btrfs_disk_key disk_key;
+
leaf = path->nodes[0];
BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item));
-split:
- /*
- * make sure any changes to the path from split_leaf leave it
- * in a blocking state
- */
btrfs_set_path_blocking(path);
item = btrfs_item_nr(leaf, path->slots[0]);
@@ -3073,19 +3088,19 @@ split:
item_size = btrfs_item_size(leaf, item);
buf = kmalloc(item_size, GFP_NOFS);
+ if (!buf)
+ return -ENOMEM;
+
read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf,
path->slots[0]), item_size);
- slot = path->slots[0] + 1;
- leaf = path->nodes[0];
+ slot = path->slots[0] + 1;
nritems = btrfs_header_nritems(leaf);
-
if (slot != nritems) {
/* shift the items */
memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
- btrfs_item_nr_offset(slot),
- (nritems - slot) * sizeof(struct btrfs_item));
-
+ btrfs_item_nr_offset(slot),
+ (nritems - slot) * sizeof(struct btrfs_item));
}
btrfs_cpu_key_to_disk(&disk_key, new_key);
@@ -3113,16 +3128,81 @@ split:
item_size - split_offset);
btrfs_mark_buffer_dirty(leaf);
- ret = 0;
- if (btrfs_leaf_free_space(root, leaf) < 0) {
- btrfs_print_leaf(root, leaf);
- BUG();
- }
+ BUG_ON(btrfs_leaf_free_space(root, leaf) < 0);
kfree(buf);
+ return 0;
+}
+
+/*
+ * This function splits a single item into two items,
+ * giving 'new_key' to the new item and splitting the
+ * old one at split_offset (from the start of the item).
+ *
+ * The path may be released by this operation. After
+ * the split, the path is pointing to the old item. The
+ * new item is going to be in the same node as the old one.
+ *
+ * Note, the item being split must be smaller enough to live alone on
+ * a tree block with room for one extra struct btrfs_item
+ *
+ * This allows us to split the item in place, keeping a lock on the
+ * leaf the entire time.
+ */
+int btrfs_split_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_key *new_key,
+ unsigned long split_offset)
+{
+ int ret;
+ ret = setup_leaf_for_split(trans, root, path,
+ sizeof(struct btrfs_item));
+ if (ret)
+ return ret;
+
+ ret = split_item(trans, root, path, new_key, split_offset);
return ret;
}
/*
+ * This function duplicate a item, giving 'new_key' to the new item.
+ * It guarantees both items live in the same tree leaf and the new item
+ * is contiguous with the original item.
+ *
+ * This allows us to split file extent in place, keeping a lock on the
+ * leaf the entire time.
+ */
+int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_key *new_key)
+{
+ struct extent_buffer *leaf;
+ int ret;
+ u32 item_size;
+
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+ ret = setup_leaf_for_split(trans, root, path,
+ item_size + sizeof(struct btrfs_item));
+ if (ret)
+ return ret;
+
+ path->slots[0]++;
+ ret = setup_items_for_insert(trans, root, path, new_key, &item_size,
+ item_size, item_size +
+ sizeof(struct btrfs_item), 1);
+ BUG_ON(ret);
+
+ leaf = path->nodes[0];
+ memcpy_extent_buffer(leaf,
+ btrfs_item_ptr_offset(leaf, path->slots[0]),
+ btrfs_item_ptr_offset(leaf, path->slots[0] - 1),
+ item_size);
+ return 0;
+}
+
+/*
* make the item pointed to by the path smaller. new_size indicates
* how small to make it, and from_end tells us if we just chop bytes
* off the end of the item or if we shift the item to chop bytes off
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 444b3e9b92a4..e3b58001162d 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2089,6 +2089,10 @@ int btrfs_split_item(struct btrfs_trans_handle *trans,
struct btrfs_path *path,
struct btrfs_key *new_key,
unsigned long split_offset);
+int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_key *new_key);
int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_key *key, struct btrfs_path *p, int
ins_len, int cow);
generated by cgit v1.2.3 (git 2.0.4) at 2024-06-22 13:17:47 +0000