Btrfs: Set the btree inode i_size to OFFSET_MAX

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

1 files changed, 26 insertions, 7 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 2de2b00afebc..9d648f2f41a5 100644
--- 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);