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-rw-r--r--fs/btrfs/ctree.c181
1 files changed, 115 insertions, 66 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 32facf8d7319..b5d203045dc7 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -65,6 +65,91 @@ static unsigned int leaf_data_end(const struct extent_buffer *leaf)
return btrfs_item_offset(leaf, nr - 1);
}
+/*
+ * Move data in a @leaf (using memmove, safe for overlapping ranges).
+ *
+ * @leaf: leaf that we're doing a memmove on
+ * @dst_offset: item data offset we're moving to
+ * @src_offset: item data offset were' moving from
+ * @len: length of the data we're moving
+ *
+ * Wrapper around memmove_extent_buffer() that takes into account the header on
+ * the leaf. The btrfs_item offset's start directly after the header, so we
+ * have to adjust any offsets to account for the header in the leaf. This
+ * handles that math to simplify the callers.
+ */
+static inline void memmove_leaf_data(const struct extent_buffer *leaf,
+ unsigned long dst_offset,
+ unsigned long src_offset,
+ unsigned long len)
+{
+ memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + dst_offset,
+ BTRFS_LEAF_DATA_OFFSET + src_offset, len);
+}
+
+/*
+ * Copy item data from @src into @dst at the given @offset.
+ *
+ * @dst: destination leaf that we're copying into
+ * @src: source leaf that we're copying from
+ * @dst_offset: item data offset we're copying to
+ * @src_offset: item data offset were' copying from
+ * @len: length of the data we're copying
+ *
+ * Wrapper around copy_extent_buffer() that takes into account the header on
+ * the leaf. The btrfs_item offset's start directly after the header, so we
+ * have to adjust any offsets to account for the header in the leaf. This
+ * handles that math to simplify the callers.
+ */
+static inline void copy_leaf_data(const struct extent_buffer *dst,
+ const struct extent_buffer *src,
+ unsigned long dst_offset,
+ unsigned long src_offset, unsigned long len)
+{
+ copy_extent_buffer(dst, src, BTRFS_LEAF_DATA_OFFSET + dst_offset,
+ BTRFS_LEAF_DATA_OFFSET + src_offset, len);
+}
+
+/*
+ * Move items in a @leaf (using memmove).
+ *
+ * @dst: destination leaf for the items
+ * @dst_item: the item nr we're copying into
+ * @src_item: the item nr we're copying from
+ * @nr_items: the number of items to copy
+ *
+ * Wrapper around memmove_extent_buffer() that does the math to get the
+ * appropriate offsets into the leaf from the item numbers.
+ */
+static inline void memmove_leaf_items(const struct extent_buffer *leaf,
+ int dst_item, int src_item, int nr_items)
+{
+ memmove_extent_buffer(leaf, btrfs_item_nr_offset(leaf, dst_item),
+ btrfs_item_nr_offset(leaf, src_item),
+ nr_items * sizeof(struct btrfs_item));
+}
+
+/*
+ * Copy items from @src into @dst at the given @offset.
+ *
+ * @dst: destination leaf for the items
+ * @src: source leaf for the items
+ * @dst_item: the item nr we're copying into
+ * @src_item: the item nr we're copying from
+ * @nr_items: the number of items to copy
+ *
+ * Wrapper around copy_extent_buffer() that does the math to get the
+ * appropriate offsets into the leaf from the item numbers.
+ */
+static inline void copy_leaf_items(const struct extent_buffer *dst,
+ const struct extent_buffer *src,
+ int dst_item, int src_item, int nr_items)
+{
+ copy_extent_buffer(dst, src, btrfs_item_nr_offset(dst, dst_item),
+ btrfs_item_nr_offset(src, src_item),
+ nr_items * sizeof(struct btrfs_item));
+}
+
int btrfs_super_csum_size(const struct btrfs_super_block *s)
{
u16 t = btrfs_super_csum_type(s);
@@ -3022,25 +3107,17 @@ static noinline int __push_leaf_right(struct btrfs_path *path,
/* make room in the right data area */
data_end = leaf_data_end(right);
- memmove_extent_buffer(right,
- BTRFS_LEAF_DATA_OFFSET + data_end - push_space,
- BTRFS_LEAF_DATA_OFFSET + data_end,
- BTRFS_LEAF_DATA_SIZE(fs_info) - data_end);
+ memmove_leaf_data(right, data_end - push_space, data_end,
+ BTRFS_LEAF_DATA_SIZE(fs_info) - data_end);
/* copy from the left data area */
- copy_extent_buffer(right, left, BTRFS_LEAF_DATA_OFFSET +
- BTRFS_LEAF_DATA_SIZE(fs_info) - push_space,
- BTRFS_LEAF_DATA_OFFSET + leaf_data_end(left),
- push_space);
+ copy_leaf_data(right, left, BTRFS_LEAF_DATA_SIZE(fs_info) - push_space,
+ leaf_data_end(left), push_space);
- memmove_extent_buffer(right, btrfs_item_nr_offset(right, push_items),
- btrfs_item_nr_offset(right, 0),
- right_nritems * sizeof(struct btrfs_item));
+ memmove_leaf_items(right, push_items, 0, right_nritems);
/* copy the items from left to right */
- copy_extent_buffer(right, left, btrfs_item_nr_offset(right, 0),
- btrfs_item_nr_offset(left, left_nritems - push_items),
- push_items * sizeof(struct btrfs_item));
+ copy_leaf_items(right, left, 0, left_nritems - push_items, push_items);
/* update the item pointers */
btrfs_init_map_token(&token, right);
@@ -3232,19 +3309,13 @@ static noinline int __push_leaf_left(struct btrfs_path *path, int data_size,
WARN_ON(!empty && push_items == btrfs_header_nritems(right));
/* push data from right to left */
- copy_extent_buffer(left, right,
- btrfs_item_nr_offset(left, btrfs_header_nritems(left)),
- btrfs_item_nr_offset(right, 0),
- push_items * sizeof(struct btrfs_item));
+ copy_leaf_items(left, right, btrfs_header_nritems(left), 0, push_items);
push_space = BTRFS_LEAF_DATA_SIZE(fs_info) -
btrfs_item_offset(right, push_items - 1);
- copy_extent_buffer(left, right, BTRFS_LEAF_DATA_OFFSET +
- leaf_data_end(left) - push_space,
- BTRFS_LEAF_DATA_OFFSET +
- btrfs_item_offset(right, push_items - 1),
- push_space);
+ copy_leaf_data(left, right, leaf_data_end(left) - push_space,
+ btrfs_item_offset(right, push_items - 1), push_space);
old_left_nritems = btrfs_header_nritems(left);
BUG_ON(old_left_nritems <= 0);
@@ -3267,15 +3338,12 @@ static noinline int __push_leaf_left(struct btrfs_path *path, int data_size,
if (push_items < right_nritems) {
push_space = btrfs_item_offset(right, push_items - 1) -
leaf_data_end(right);
- memmove_extent_buffer(right, BTRFS_LEAF_DATA_OFFSET +
- BTRFS_LEAF_DATA_SIZE(fs_info) - push_space,
- BTRFS_LEAF_DATA_OFFSET +
- leaf_data_end(right), push_space);
+ memmove_leaf_data(right,
+ BTRFS_LEAF_DATA_SIZE(fs_info) - push_space,
+ leaf_data_end(right), push_space);
- memmove_extent_buffer(right, btrfs_item_nr_offset(right, 0),
- btrfs_item_nr_offset(left, push_items),
- (btrfs_header_nritems(right) - push_items) *
- sizeof(struct btrfs_item));
+ memmove_leaf_items(right, 0, push_items,
+ btrfs_header_nritems(right) - push_items);
}
btrfs_init_map_token(&token, right);
@@ -3407,14 +3475,10 @@ static noinline void copy_for_split(struct btrfs_trans_handle *trans,
btrfs_set_header_nritems(right, nritems);
data_copy_size = btrfs_item_data_end(l, mid) - leaf_data_end(l);
- copy_extent_buffer(right, l, btrfs_item_nr_offset(right, 0),
- btrfs_item_nr_offset(l, mid),
- nritems * sizeof(struct btrfs_item));
+ copy_leaf_items(right, l, 0, mid, nritems);
- copy_extent_buffer(right, l,
- BTRFS_LEAF_DATA_OFFSET + BTRFS_LEAF_DATA_SIZE(fs_info) -
- data_copy_size, BTRFS_LEAF_DATA_OFFSET +
- leaf_data_end(l), data_copy_size);
+ copy_leaf_data(right, l, BTRFS_LEAF_DATA_SIZE(fs_info) - data_copy_size,
+ leaf_data_end(l), data_copy_size);
rt_data_off = BTRFS_LEAF_DATA_SIZE(fs_info) - btrfs_item_data_end(l, mid);
@@ -3784,9 +3848,7 @@ static noinline int split_item(struct btrfs_path *path,
nritems = btrfs_header_nritems(leaf);
if (slot != nritems) {
/* shift the items */
- memmove_extent_buffer(leaf, btrfs_item_nr_offset(leaf, slot + 1),
- btrfs_item_nr_offset(leaf, slot),
- (nritems - slot) * sizeof(struct btrfs_item));
+ memmove_leaf_items(leaf, slot + 1, slot, nritems - slot);
}
btrfs_cpu_key_to_disk(&disk_key, new_key);
@@ -3897,9 +3959,8 @@ void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end)
/* shift the data */
if (from_end) {
- memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET +
- data_end + size_diff, BTRFS_LEAF_DATA_OFFSET +
- data_end, old_data_start + new_size - data_end);
+ memmove_leaf_data(leaf, data_end + size_diff, data_end,
+ old_data_start + new_size - data_end);
} else {
struct btrfs_disk_key disk_key;
u64 offset;
@@ -3924,9 +3985,8 @@ void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end)
}
}
- memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET +
- data_end + size_diff, BTRFS_LEAF_DATA_OFFSET +
- data_end, old_data_start - data_end);
+ memmove_leaf_data(leaf, data_end + size_diff, data_end,
+ old_data_start - data_end);
offset = btrfs_disk_key_offset(&disk_key);
btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
@@ -3991,9 +4051,8 @@ void btrfs_extend_item(struct btrfs_path *path, u32 data_size)
}
/* shift the data */
- memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET +
- data_end - data_size, BTRFS_LEAF_DATA_OFFSET +
- data_end, old_data - data_end);
+ memmove_leaf_data(leaf, data_end - data_size, data_end,
+ old_data - data_end);
data_end = old_data;
old_size = btrfs_item_size(leaf, slot);
@@ -4077,16 +4136,11 @@ static void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *p
ioff - batch->total_data_size);
}
/* shift the items */
- memmove_extent_buffer(leaf,
- btrfs_item_nr_offset(leaf, slot + batch->nr),
- btrfs_item_nr_offset(leaf, slot),
- (nritems - slot) * sizeof(struct btrfs_item));
+ memmove_leaf_items(leaf, slot + batch->nr, slot, nritems - slot);
/* shift the data */
- memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET +
- data_end - batch->total_data_size,
- BTRFS_LEAF_DATA_OFFSET + data_end,
- old_data - data_end);
+ memmove_leaf_data(leaf, data_end - batch->total_data_size,
+ data_end, old_data - data_end);
data_end = old_data;
}
@@ -4321,10 +4375,8 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
for (i = 0; i < nr; i++)
dsize += btrfs_item_size(leaf, slot + i);
- memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET +
- data_end + dsize,
- BTRFS_LEAF_DATA_OFFSET + data_end,
- last_off - data_end);
+ memmove_leaf_data(leaf, data_end + dsize, data_end,
+ last_off - data_end);
btrfs_init_map_token(&token, leaf);
for (i = slot + nr; i < nritems; i++) {
@@ -4334,10 +4386,7 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
btrfs_set_token_item_offset(&token, i, ioff + dsize);
}
- memmove_extent_buffer(leaf, btrfs_item_nr_offset(leaf, slot),
- btrfs_item_nr_offset(leaf, slot + nr),
- sizeof(struct btrfs_item) *
- (nritems - slot - nr));
+ memmove_leaf_items(leaf, slot, slot + nr, nritems - slot - nr);
}
btrfs_set_header_nritems(leaf, nritems - nr);
nritems -= nr;