Btrfs: working file_write, reorganized key flags

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 47 insertions, 19 deletions

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index ff8f3339c684..8cc3c1d15412 100644
--- 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;
         }