Btrfs: Set the btree inode i_size to OFFSET_MAX

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

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 2de2b00afebc933f91603190f117e1d46cc71771..9d648f2f41a5a95445c0cc549f9865d11d3fd0c8 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -88,19 +88,35 @@ struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
                goto out;
        }
        em->start = 0;
-       em->len = i_size_read(inode);
+       em->len = (u64)-1;
        em->block_start = 0;
        em->bdev = inode->i_sb->s_bdev;
 
        spin_lock(&em_tree->lock);
        ret = add_extent_mapping(em_tree, em);
        if (ret == -EEXIST) {
+               u64 failed_start = em->start;
+               u64 failed_len = em->len;
+
+               printk("failed to insert %Lu %Lu -> %Lu into tree\n",
+                      em->start, em->len, em->block_start);
                free_extent_map(em);
                em = lookup_extent_mapping(em_tree, start, len);
-               if (em)
+               if (em) {
+                       printk("after failing, found %Lu %Lu %Lu\n",
+                              em->start, em->len, em->block_start);
                        ret = 0;
-               else
+               } else {
+                       em = lookup_extent_mapping(em_tree, failed_start,
+                                                  failed_len);
+                       if (em) {
+                               printk("double failure lookup gives us "
+                                      "%Lu %Lu -> %Lu\n", em->start,
+                                      em->len, em->block_start);
+                               free_extent_map(em);
+                       }
                        ret = -EIO;
+               }
        } else if (ret) {
                free_extent_map(em);
                em = NULL;
@@ -1108,7 +1124,13 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        fs_info->btree_inode = new_inode(sb);
        fs_info->btree_inode->i_ino = 1;
        fs_info->btree_inode->i_nlink = 1;
-       fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
+
+       /*
+        * we set the i_size on the btree inode to the max possible int.
+        * the real end of the address space is determined by all of
+        * the devices in the system
+        */
+       fs_info->btree_inode->i_size = OFFSET_MAX;
        fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
        fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
 
@@ -1196,9 +1218,6 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        tree_root->stripesize = stripesize;
        sb_set_blocksize(sb, sectorsize);
 
-       i_size_write(fs_info->btree_inode,
-                    btrfs_super_total_bytes(disk_super));
-
        if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
                    sizeof(disk_super->magic))) {
                printk("btrfs: valid FS not found on %s\n", sb->s_id);