Btrfs: early work to file_write in big extents
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index d9fd7f4..93d42d6 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -3,6 +3,9 @@
#include "disk-io.h"
#include "transaction.h"
+#define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
+ sizeof(struct btrfs_item)) / \
+ sizeof(struct btrfs_csum_item)) - 1))
int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 offset,
@@ -43,6 +46,54 @@
return 0;
}
+static struct btrfs_csum_item *__lookup_csum_item(struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 objectid, u64 offset)
+{
+ int ret;
+ struct btrfs_key file_key;
+ struct btrfs_key found_key;
+ struct btrfs_csum_item *item;
+ struct btrfs_leaf *leaf;
+ u64 csum_offset = 0;
+
+ file_key.objectid = objectid;
+ file_key.offset = offset;
+ file_key.flags = 0;
+ btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
+ ret = btrfs_search_slot(NULL, root, &file_key, path, 0, 0);
+ if (ret < 0)
+ goto fail;
+ leaf = btrfs_buffer_leaf(path->nodes[0]);
+ if (ret > 0) {
+ ret = 1;
+ if (path->slots[0] == 0)
+ goto fail;
+ path->slots[0]--;
+ btrfs_disk_key_to_cpu(&found_key,
+ &leaf->items[path->slots[0]].key);
+ if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
+ found_key.objectid != objectid) {
+ goto fail;
+ }
+ csum_offset = (offset - found_key.offset) >>
+ root->fs_info->sb->s_blocksize_bits;
+ if (csum_offset >=
+ btrfs_item_size(leaf->items + path->slots[0]) /
+ sizeof(struct btrfs_csum_item)) {
+ goto fail;
+ }
+ }
+ item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
+ item += csum_offset;
+ return item;
+fail:
+ if (ret > 0)
+ ret = -EIO;
+ return ERR_PTR(ret);
+}
+
+
int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 objectid,
@@ -52,11 +103,16 @@
struct btrfs_key file_key;
int ins_len = mod < 0 ? -1 : 0;
int cow = mod != 0;
+ struct btrfs_csum_item *csum_item;
+ csum_item = __lookup_csum_item(root, path, objectid, offset);
+ if (IS_ERR(csum_item))
+ return PTR_ERR(csum_item);
file_key.objectid = objectid;
- file_key.offset = offset;
+ file_key.offset = btrfs_csum_extent_offset(csum_item);
file_key.flags = 0;
btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
+ btrfs_release_path(root, path);
ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
return ret;
}
@@ -64,12 +120,16 @@
int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 offset,
+ u64 extent_offset,
char *data, size_t len)
{
int ret;
struct btrfs_key file_key;
+ struct btrfs_key found_key;
struct btrfs_path *path;
struct btrfs_csum_item *item;
+ struct btrfs_leaf *leaf;
+ u64 csum_offset;
path = btrfs_alloc_path();
BUG_ON(!path);
@@ -78,14 +138,50 @@
file_key.offset = offset;
file_key.flags = 0;
btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
+ ret = btrfs_search_slot(trans, root, &file_key, path,
+ sizeof(struct btrfs_csum_item), 1);
+ if (ret < 0)
+ goto fail;
+ if (ret == 0) {
+ csum_offset = 0;
+ goto csum;
+ }
+ if (path->slots[0] == 0) {
+ btrfs_release_path(root, path);
+ goto insert;
+ }
+ path->slots[0]--;
+ leaf = btrfs_buffer_leaf(path->nodes[0]);
+ btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key);
+ csum_offset = (offset - found_key.offset) >>
+ root->fs_info->sb->s_blocksize_bits;
+ if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
+ found_key.objectid != objectid ||
+ csum_offset >= MAX_CSUM_ITEMS(root)) {
+ btrfs_release_path(root, path);
+ goto insert;
+ }
+ if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
+ sizeof(struct btrfs_csum_item)) {
+ ret = btrfs_extend_item(trans, root, path,
+ sizeof(struct btrfs_csum_item));
+ BUG_ON(ret);
+ goto csum;
+ }
+
+insert:
+ csum_offset = 0;
ret = btrfs_insert_empty_item(trans, root, path, &file_key,
- BTRFS_CSUM_SIZE);
+ sizeof(struct btrfs_csum_item));
if (ret != 0 && ret != -EEXIST)
goto fail;
+csum:
item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
struct btrfs_csum_item);
ret = 0;
+ item += csum_offset;
ret = btrfs_csum_data(root, data, len, item->csum);
+ btrfs_set_csum_extent_offset(item, extent_offset);
btrfs_mark_buffer_dirty(path->nodes[0]);
fail:
btrfs_release_path(root, path);
@@ -111,12 +207,13 @@
file_key.flags = 0;
btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
mutex_lock(&root->fs_info->fs_mutex);
- ret = btrfs_search_slot(NULL, root, &file_key, path, 0, 0);
- if (ret)
+
+ item = __lookup_csum_item(root, path, objectid, offset);
+ if (IS_ERR(item)) {
+ ret = PTR_ERR(item);
goto fail;
- item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
- struct btrfs_csum_item);
- ret = 0;
+ }
+
ret = btrfs_csum_data(root, data, len, result);
WARN_ON(ret);
if (memcmp(result, item->csum, BTRFS_CSUM_SIZE))