Btrfs: working file_write, reorganized key flags

[linux-2.6-block.git] / fs / btrfs / file-item.c

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index ff8f3339c684faa7436cab4c9265b7ed902d8379..8cc3c1d15412309de185f34c85d63783012fc475 100644 (file)
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -4,7 +4,7 @@
 #include "transaction.h"
 
 #define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
-                                sizeof(struct btrfs_item)) / \
+                                sizeof(struct btrfs_item) * 2) / \
                                sizeof(struct btrfs_csum_item)) - 1))
 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
                               struct btrfs_root *root,
@@ -19,11 +19,6 @@ int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
        path = btrfs_alloc_path();
        BUG_ON(!path);
        btrfs_init_path(path);
-       /*
-       ret = btrfs_alloc_extent(trans, root, num_blocks, hint_block,
-                                (u64)-1, &ins);
-                                */
-       BUG_ON(ret);
        file_key.objectid = objectid;
        file_key.offset = pos;
        file_key.flags = 0;
@@ -40,6 +35,7 @@ int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
        btrfs_set_file_extent_num_blocks(item, num_blocks);
        btrfs_set_file_extent_generation(item, trans->transid);
        btrfs_mark_buffer_dirty(path->nodes[0]);
+
        btrfs_release_path(root, path);
        btrfs_free_path(path);
        return 0;
@@ -57,6 +53,7 @@ struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
        struct btrfs_csum_item *item;
        struct btrfs_leaf *leaf;
        u64 csum_offset = 0;
+       int csums_in_item;
 
        file_key.objectid = objectid;
        file_key.offset = offset;
@@ -79,9 +76,11 @@ struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
                }
                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)) {
+               csums_in_item = btrfs_item_size(leaf->items + path->slots[0]);
+               csums_in_item /= sizeof(struct btrfs_csum_item);
+
+               if (csum_offset >= csums_in_item) {
+                       ret = -EFBIG;
                        goto fail;
                }
        }
@@ -128,16 +127,36 @@ int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
 
        path = btrfs_alloc_path();
        BUG_ON(!path);
-       btrfs_init_path(path);
 
-       item = btrfs_lookup_csum(trans, root, path, objectid, offset, 0);
-       if (!IS_ERR(item))
-               goto found;
-       btrfs_release_path(root, path);
        file_key.objectid = objectid;
        file_key.offset = offset;
        file_key.flags = 0;
        btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
+
+       item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
+       if (!IS_ERR(item))
+               goto found;
+       ret = PTR_ERR(item);
+       if (ret == -EFBIG) {
+               u32 item_size;
+               /* we found one, but it isn't big enough yet */
+               leaf = btrfs_buffer_leaf(path->nodes[0]);
+               item_size = btrfs_item_size(leaf->items + path->slots[0]);
+               if ((item_size / sizeof(struct btrfs_csum_item)) >=
+                   MAX_CSUM_ITEMS(root)) {
+                       /* already at max size, make a new one */
+                       goto insert;
+               }
+       } else {
+               /* we didn't find a csum item, insert one */
+               goto insert;
+       }
+
+       /*
+        * at this point, we know the tree has an item, but it isn't big
+        * enough yet to put our csum in.  Grow it
+        */
+       btrfs_release_path(root, path);
        ret = btrfs_search_slot(trans, root, &file_key, path,
                                sizeof(struct btrfs_csum_item), 1);
        if (ret < 0)
@@ -146,7 +165,6 @@ int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
                BUG();
        }
        if (path->slots[0] == 0) {
-               btrfs_release_path(root, path);
                goto insert;
        }
        path->slots[0]--;
@@ -157,29 +175,36 @@ int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
        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);
+               WARN_ON(1);
                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));
+               u32 diff = (csum_offset + 1) * sizeof(struct btrfs_csum_item);
+               diff = diff - btrfs_item_size(leaf->items + path->slots[0]);
+               WARN_ON(diff != sizeof(struct btrfs_csum_item));
+               ret = btrfs_extend_item(trans, root, path, diff);
                BUG_ON(ret);
                goto csum;
        }
 
 insert:
+       btrfs_release_path(root, path);
        csum_offset = 0;
        ret = btrfs_insert_empty_item(trans, root, path, &file_key,
                                      sizeof(struct btrfs_csum_item));
-       if (ret != 0 && ret != -EEXIST)
+       if (ret != 0) {
+               printk("at insert for %Lu %u %Lu ret is %d\n", file_key.objectid, file_key.flags, file_key.offset, ret);
+               WARN_ON(1);
                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;
 found:
+       btrfs_check_bounds(item->csum, BTRFS_CSUM_SIZE, path->nodes[0]->b_data, root->fs_info->sb->s_blocksize);
        ret = btrfs_csum_data(root, data, len, item->csum);
        btrfs_mark_buffer_dirty(path->nodes[0]);
 fail:
@@ -210,6 +235,9 @@ int btrfs_csum_verify_file_block(struct btrfs_root *root,
        item = btrfs_lookup_csum(NULL, root, path, objectid, offset, 0);
        if (IS_ERR(item)) {
                ret = PTR_ERR(item);
+               /* a csum that isn't present is a preallocated region. */
+               if (ret == -ENOENT || ret == -EFBIG)
+                       ret = 1;
                goto fail;
        }