Btrfs: create a logical->phsyical block number mapping scheme
authorChris Mason <chris.mason@oracle.com>
Wed, 11 Apr 2007 19:53:25 +0000 (15:53 -0400)
committerDavid Woodhouse <dwmw2@hera.kernel.org>
Wed, 11 Apr 2007 19:53:25 +0000 (15:53 -0400)
Signed-off-by: Chris Mason <chris.mason@oracle.com>
fs/btrfs/ctree.c
fs/btrfs/ctree.h
fs/btrfs/disk-io.c
fs/btrfs/disk-io.h
fs/btrfs/extent-tree.c
fs/btrfs/super.c
fs/btrfs/transaction.c

index f31ac84..e2fc6f0 100644 (file)
@@ -66,21 +66,21 @@ static int btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root
        if (buf->b_size != root->blocksize || cow->b_size != root->blocksize)
                WARN_ON(1);
        memcpy(cow_node, btrfs_buffer_node(buf), root->blocksize);
-       btrfs_set_header_blocknr(&cow_node->header, cow->b_blocknr);
+       btrfs_set_header_blocknr(&cow_node->header, bh_blocknr(cow));
        btrfs_set_header_generation(&cow_node->header, trans->transid);
        btrfs_inc_ref(trans, root, buf);
        if (buf == root->node) {
                root->node = cow;
                get_bh(cow);
                if (buf != root->commit_root) {
-                       btrfs_free_extent(trans, root, buf->b_blocknr, 1, 1);
+                       btrfs_free_extent(trans, root, bh_blocknr(buf), 1, 1);
                }
                btrfs_block_release(root, buf);
        } else {
                btrfs_set_node_blockptr(btrfs_buffer_node(parent), parent_slot,
-                                       cow->b_blocknr);
+                                       bh_blocknr(cow));
                btrfs_mark_buffer_dirty(parent);
-               btrfs_free_extent(trans, root, buf->b_blocknr, 1, 1);
+               btrfs_free_extent(trans, root, bh_blocknr(buf), 1, 1);
        }
        btrfs_block_release(root, buf);
        mark_buffer_dirty(cow);
@@ -312,7 +312,7 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
         */
        if (!parent_buf) {
                struct buffer_head *child;
-               u64 blocknr = mid_buf->b_blocknr;
+               u64 blocknr = bh_blocknr(mid_buf);
 
                if (btrfs_header_nritems(&mid->header) != 1)
                        return 0;
@@ -361,7 +361,7 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
                if (wret < 0)
                        ret = wret;
                if (btrfs_header_nritems(&right->header) == 0) {
-                       u64 blocknr = right_buf->b_blocknr;
+                       u64 blocknr = bh_blocknr(right_buf);
                        clean_tree_block(trans, root, right_buf);
                        wait_on_buffer(right_buf);
                        btrfs_block_release(root, right_buf);
@@ -400,7 +400,7 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
        }
        if (btrfs_header_nritems(&mid->header) == 0) {
                /* we've managed to empty the middle node, drop it */
-               u64 blocknr = mid_buf->b_blocknr;
+               u64 blocknr = bh_blocknr(mid_buf);
                clean_tree_block(trans, root, mid_buf);
                wait_on_buffer(mid_buf);
                btrfs_block_release(root, mid_buf);
@@ -686,7 +686,7 @@ static int insert_new_root(struct btrfs_trans_handle *trans, struct btrfs_root
        memset(c, 0, root->blocksize);
        btrfs_set_header_nritems(&c->header, 1);
        btrfs_set_header_level(&c->header, level);
-       btrfs_set_header_blocknr(&c->header, t->b_blocknr);
+       btrfs_set_header_blocknr(&c->header, bh_blocknr(t));
        btrfs_set_header_generation(&c->header, trans->transid);
        lower = btrfs_buffer_node(path->nodes[level-1]);
        memcpy(c->header.fsid, root->fs_info->disk_super->fsid,
@@ -697,7 +697,7 @@ static int insert_new_root(struct btrfs_trans_handle *trans, struct btrfs_root
                lower_key = &lower->ptrs[0].key;
        btrfs_memcpy(root, c, &c->ptrs[0].key, lower_key,
                     sizeof(struct btrfs_disk_key));
-       btrfs_set_node_blockptr(c, 0, path->nodes[level - 1]->b_blocknr);
+       btrfs_set_node_blockptr(c, 0, bh_blocknr(path->nodes[level - 1]));
 
        btrfs_mark_buffer_dirty(t);
 
@@ -780,7 +780,7 @@ static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
        split = btrfs_buffer_node(split_buffer);
        btrfs_set_header_flags(&split->header, btrfs_header_flags(&c->header));
        btrfs_set_header_level(&split->header, btrfs_header_level(&c->header));
-       btrfs_set_header_blocknr(&split->header, split_buffer->b_blocknr);
+       btrfs_set_header_blocknr(&split->header, bh_blocknr(split_buffer));
        btrfs_set_header_generation(&split->header, trans->transid);
        memcpy(split->header.fsid, root->fs_info->disk_super->fsid,
               sizeof(split->header.fsid));
@@ -794,7 +794,7 @@ static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
        btrfs_mark_buffer_dirty(t);
        btrfs_mark_buffer_dirty(split_buffer);
        wret = insert_ptr(trans, root, path, &split->ptrs[0].key,
-                         split_buffer->b_blocknr, path->slots[level + 1] + 1,
+                         bh_blocknr(split_buffer), path->slots[level + 1] + 1,
                          level + 1);
        if (wret)
                ret = wret;
@@ -1138,7 +1138,7 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
        BUG_ON(!right_buffer);
        right = btrfs_buffer_leaf(right_buffer);
        memset(&right->header, 0, sizeof(right->header));
-       btrfs_set_header_blocknr(&right->header, right_buffer->b_blocknr);
+       btrfs_set_header_blocknr(&right->header, bh_blocknr(right_buffer));
        btrfs_set_header_generation(&right->header, trans->transid);
        btrfs_set_header_level(&right->header, 0);
        memcpy(right->header.fsid, root->fs_info->disk_super->fsid,
@@ -1152,7 +1152,7 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
                                btrfs_set_header_nritems(&right->header, 0);
                                wret = insert_ptr(trans, root, path,
                                                  &disk_key,
-                                                 right_buffer->b_blocknr,
+                                                 bh_blocknr(right_buffer),
                                                  path->slots[1] + 1, 1);
                                if (wret)
                                        ret = wret;
@@ -1173,7 +1173,7 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
                                btrfs_set_header_nritems(&right->header, 0);
                                wret = insert_ptr(trans, root, path,
                                                  &disk_key,
-                                                 right_buffer->b_blocknr,
+                                                 bh_blocknr(right_buffer),
                                                  path->slots[1] - 1, 1);
                                if (wret)
                                        ret = wret;
@@ -1207,7 +1207,7 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
        btrfs_set_header_nritems(&l->header, mid);
        ret = 0;
        wret = insert_ptr(trans, root, path, &right->items[0].key,
-                         right_buffer->b_blocknr, path->slots[1] + 1, 1);
+                         bh_blocknr(right_buffer), path->slots[1] + 1, 1);
        if (wret)
                ret = wret;
        btrfs_mark_buffer_dirty(right_buffer);
@@ -1228,7 +1228,7 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
        BUG_ON(!right_buffer);
        right = btrfs_buffer_leaf(right_buffer);
        memset(&right->header, 0, sizeof(right->header));
-       btrfs_set_header_blocknr(&right->header, right_buffer->b_blocknr);
+       btrfs_set_header_blocknr(&right->header, bh_blocknr(right_buffer));
        btrfs_set_header_generation(&right->header, trans->transid);
        btrfs_set_header_level(&right->header, 0);
        memcpy(right->header.fsid, root->fs_info->disk_super->fsid,
@@ -1237,7 +1237,7 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
        btrfs_set_header_nritems(&right->header, 0);
        wret = insert_ptr(trans, root, path,
                          &disk_key,
-                         right_buffer->b_blocknr,
+                         bh_blocknr(right_buffer),
                          path->slots[1], 1);
        if (wret)
                ret = wret;
@@ -1456,7 +1456,7 @@ int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                        if (wret)
                                ret = wret;
                        wret = btrfs_free_extent(trans, root,
-                                                leaf_buf->b_blocknr, 1, 1);
+                                                bh_blocknr(leaf_buf), 1, 1);
                        if (wret)
                                ret = wret;
                }
@@ -1487,7 +1487,7 @@ int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                                        ret = wret;
                        }
                        if (btrfs_header_nritems(&leaf->header) == 0) {
-                               u64 blocknr = leaf_buf->b_blocknr;
+                               u64 blocknr = bh_blocknr(leaf_buf);
                                clean_tree_block(trans, root, leaf_buf);
                                wait_on_buffer(leaf_buf);
                                wret = del_ptr(trans, root, path, 1, slot);
index 01310de..454eb88 100644 (file)
@@ -242,6 +242,7 @@ struct btrfs_fs_info {
        struct radix_tree_root fs_roots_radix;
        struct radix_tree_root pending_del_radix;
        struct radix_tree_root pinned_radix;
+       struct radix_tree_root dev_radix;
        u64 generation;
        struct btrfs_transaction *running_transaction;
        struct btrfs_super_block *disk_super;
index e092332..c872a7e 100644 (file)
 #include "transaction.h"
 #include "btrfs_inode.h"
 
+struct dev_lookup {
+       u64 block_start;
+       u64 num_blocks;
+       struct block_device *bdev;
+};
+
+u64 bh_blocknr(struct buffer_head *bh)
+{
+       int blkbits = bh->b_page->mapping->host->i_blkbits;
+       u64 blocknr = bh->b_page->index << (PAGE_CACHE_SHIFT - blkbits);
+       unsigned long offset;
+
+       if (PageHighMem(bh->b_page))
+               offset = (unsigned long)bh->b_data;
+       else
+               offset = bh->b_data - (char *)page_address(bh->b_page);
+       blocknr += offset >> (PAGE_CACHE_SHIFT - blkbits);
+       return blocknr;
+}
+
 static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf)
 {
        struct btrfs_node *node = btrfs_buffer_node(buf);
-       if (buf->b_blocknr != btrfs_header_blocknr(&node->header)) {
+       if (bh_blocknr(buf) != btrfs_header_blocknr(&node->header)) {
                BUG();
        }
        return 0;
@@ -40,7 +60,7 @@ struct buffer_head *btrfs_find_tree_block(struct btrfs_root *root, u64 blocknr)
        head = page_buffers(page);
        bh = head;
        do {
-               if (buffer_mapped(bh) && bh->b_blocknr == blocknr) {
+               if (buffer_mapped(bh) && bh_blocknr(bh) == blocknr) {
                        ret = bh;
                        get_bh(bh);
                        goto out_unlock;
@@ -56,6 +76,33 @@ out_unlock:
        return ret;
 }
 
+static int map_bh_to_logical(struct btrfs_root *root, struct buffer_head *bh,
+                            u64 logical)
+{
+       struct dev_lookup *lookup[2];
+       char b[BDEVNAME_SIZE];
+
+       int ret;
+
+       root = root->fs_info->dev_root;
+       ret = radix_tree_gang_lookup(&root->fs_info->dev_radix,
+                                    (void **)lookup,
+                                    (unsigned long)logical,
+                                    ARRAY_SIZE(lookup));
+       if (ret == 0 || lookup[0]->block_start > logical ||
+           lookup[0]->block_start + lookup[0]->num_blocks <= logical) {
+               ret = -ENOENT;
+               goto out;
+       }
+       bh->b_bdev = lookup[0]->bdev;
+       bh->b_blocknr = logical - lookup[0]->block_start;
+printk("logical mapping %Lu to %lu bdev  %s\n", logical, bh->b_blocknr, bdevname(bh->b_bdev, b));
+       set_buffer_mapped(bh);
+       ret = 0;
+out:
+       return ret;
+}
+
 struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
                                                 u64 blocknr)
 {
@@ -66,6 +113,7 @@ struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
        struct buffer_head *bh;
        struct buffer_head *head;
        struct buffer_head *ret = NULL;
+       int err;
        u64 first_block = index << (PAGE_CACHE_SHIFT - blockbits);
 
        page = grab_cache_page(mapping, index);
@@ -78,11 +126,10 @@ struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
        bh = head;
        do {
                if (!buffer_mapped(bh)) {
-                       bh->b_bdev = root->fs_info->sb->s_bdev;
-                       bh->b_blocknr = first_block;
-                       set_buffer_mapped(bh);
+                       err = map_bh_to_logical(root, bh, first_block);
+                       BUG_ON(err);
                }
-               if (bh->b_blocknr == blocknr) {
+               if (bh_blocknr(bh) == blocknr) {
                        ret = bh;
                        get_bh(bh);
                        goto out_unlock;
@@ -98,38 +145,13 @@ out_unlock:
        return ret;
 }
 
-static sector_t max_block(struct block_device *bdev)
-{
-       sector_t retval = ~((sector_t)0);
-       loff_t sz = i_size_read(bdev->bd_inode);
-
-       if (sz) {
-               unsigned int size = block_size(bdev);
-               unsigned int sizebits = blksize_bits(size);
-               retval = (sz >> sizebits);
-       }
-       return retval;
-}
-
 static int btree_get_block(struct inode *inode, sector_t iblock,
                           struct buffer_head *bh, int create)
 {
-       if (iblock >= max_block(inode->i_sb->s_bdev)) {
-               if (create)
-                       return -EIO;
-
-               /*
-                * for reads, we're just trying to fill a partial page.
-                * return a hole, they will have to call get_block again
-                * before they can fill it, and they will get -EIO at that
-                * time
-                */
-               return 0;
-       }
-       bh->b_bdev = inode->i_sb->s_bdev;
-       bh->b_blocknr = iblock;
-       set_buffer_mapped(bh);
-       return 0;
+       int err;
+       struct btrfs_root *root = BTRFS_I(bh->b_page->mapping->host)->root;
+       err = map_bh_to_logical(root, bh, iblock);
+       return err;
 }
 
 int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len,
@@ -164,8 +186,8 @@ static int csum_tree_block(struct btrfs_root *root, struct buffer_head *bh,
                return ret;
        if (verify) {
                if (memcmp(bh->b_data, result, BTRFS_CSUM_SIZE)) {
-                       printk("checksum verify failed on %lu\n",
-                              bh->b_blocknr);
+                       printk("checksum verify failed on %Lu\n",
+                              bh_blocknr(bh));
                        return 1;
                }
        } else {
@@ -386,10 +408,12 @@ struct btrfs_root *open_ctree(struct super_block *sb)
                                                GFP_NOFS);
        int ret;
        struct btrfs_super_block *disk_super;
+       struct dev_lookup *dev_lookup;
 
        init_bit_radix(&fs_info->pinned_radix);
        init_bit_radix(&fs_info->pending_del_radix);
        INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
+       INIT_RADIX_TREE(&fs_info->dev_radix, GFP_NOFS);
        sb_set_blocksize(sb, 4096);
        fs_info->running_transaction = NULL;
        fs_info->tree_root = tree_root;
@@ -422,6 +446,13 @@ struct btrfs_root *open_ctree(struct super_block *sb)
 
        __setup_root(sb->s_blocksize, tree_root,
                     fs_info, BTRFS_ROOT_TREE_OBJECTID);
+
+       dev_lookup = kmalloc(sizeof(*dev_lookup), GFP_NOFS);
+       dev_lookup->block_start = 0;
+       dev_lookup->num_blocks = (u32)-2;
+       dev_lookup->bdev = sb->s_bdev;
+       ret = radix_tree_insert(&fs_info->dev_radix, (u32)-2, dev_lookup);
+       BUG_ON(ret);
        fs_info->sb_buffer = read_tree_block(tree_root,
                                             BTRFS_SUPER_INFO_OFFSET /
                                             sb->s_blocksize);
@@ -432,6 +463,14 @@ struct btrfs_root *open_ctree(struct super_block *sb)
        if (!btrfs_super_root(disk_super))
                return NULL;
 
+       radix_tree_delete(&fs_info->dev_radix, (u32)-2);
+       dev_lookup->block_start = btrfs_super_device_block_start(disk_super);
+       dev_lookup->num_blocks = btrfs_super_device_num_blocks(disk_super);
+       ret = radix_tree_insert(&fs_info->dev_radix,
+                               dev_lookup->block_start +
+                               dev_lookup->num_blocks, dev_lookup);
+       BUG_ON(ret);
+
        fs_info->disk_super = disk_super;
        dev_root->node = read_tree_block(tree_root,
                                          btrfs_super_device_root(disk_super));
@@ -459,7 +498,7 @@ int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
        struct buffer_head *bh = root->fs_info->sb_buffer;
 
        btrfs_set_super_root(root->fs_info->disk_super,
-                            root->fs_info->tree_root->node->b_blocknr);
+                            bh_blocknr(root->fs_info->tree_root->node));
        lock_buffer(bh);
        WARN_ON(atomic_read(&bh->b_count) < 1);
        clear_buffer_dirty(bh);
@@ -506,6 +545,29 @@ int del_fs_roots(struct btrfs_fs_info *fs_info)
        }
        return 0;
 }
+static int free_dev_radix(struct btrfs_fs_info *fs_info)
+{
+       struct dev_lookup *lookup[8];
+       struct block_device *super_bdev = fs_info->sb->s_bdev;
+       int ret;
+       int i;
+       while(1) {
+               ret = radix_tree_gang_lookup(&fs_info->dev_radix,
+                                            (void **)lookup, 0,
+                                            ARRAY_SIZE(lookup));
+               if (!ret)
+                       break;
+               for (i = 0; i < ret; i++) {
+                       if (lookup[i]->bdev != super_bdev)
+                               close_bdev_excl(lookup[i]->bdev);
+                       radix_tree_delete(&fs_info->dev_radix,
+                                         lookup[i]->block_start +
+                                         lookup[i]->num_blocks);
+                       kfree(lookup[i]);
+               }
+       }
+       return 0;
+}
 
 int close_ctree(struct btrfs_root *root)
 {
@@ -537,6 +599,8 @@ int close_ctree(struct btrfs_root *root)
        crypto_free_hash(fs_info->hash_tfm);
        truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
        iput(fs_info->btree_inode);
+
+       free_dev_radix(fs_info);
        del_fs_roots(fs_info);
        kfree(fs_info->extent_root);
        kfree(fs_info->tree_root);
index 0ef6e6f..46cc5dc 100644 (file)
@@ -41,4 +41,5 @@ int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len,
                    char *result);
 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
                                      struct btrfs_key *location);
+u64 bh_blocknr(struct buffer_head *bh);
 #endif
index be9630d..d560831 100644 (file)
@@ -80,7 +80,7 @@ static int lookup_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
                       struct btrfs_root *root)
 {
-       return inc_block_ref(trans, root, root->node->b_blocknr, 1);
+       return inc_block_ref(trans, root, bh_blocknr(root->node), 1);
 }
 
 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
@@ -563,7 +563,7 @@ static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
 
        WARN_ON(*level < 0);
        WARN_ON(*level >= BTRFS_MAX_LEVEL);
-       ret = lookup_block_ref(trans, root, path->nodes[*level]->b_blocknr,
+       ret = lookup_block_ref(trans, root, bh_blocknr(path->nodes[*level]),
                               1, &refs);
        BUG_ON(ret);
        if (refs > 1)
@@ -607,7 +607,7 @@ out:
        WARN_ON(*level < 0);
        WARN_ON(*level >= BTRFS_MAX_LEVEL);
        ret = btrfs_free_extent(trans, root,
-                               path->nodes[*level]->b_blocknr, 1, 1);
+                               bh_blocknr(path->nodes[*level]), 1, 1);
        btrfs_block_release(root, path->nodes[*level]);
        path->nodes[*level] = NULL;
        *level += 1;
@@ -635,7 +635,7 @@ static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root
                        return 0;
                } else {
                        ret = btrfs_free_extent(trans, root,
-                                               path->nodes[*level]->b_blocknr,
+                                               bh_blocknr(path->nodes[*level]),
                                                1, 1);
                        BUG_ON(ret);
                        btrfs_block_release(root, path->nodes[*level]);
index 2972aaa..4ff0cc1 100644 (file)
@@ -1700,7 +1700,7 @@ static int create_subvol(struct btrfs_root *root, char *name, int namelen)
        leaf = btrfs_buffer_leaf(subvol);
        btrfs_set_header_nritems(&leaf->header, 0);
        btrfs_set_header_level(&leaf->header, 0);
-       btrfs_set_header_blocknr(&leaf->header, subvol->b_blocknr);
+       btrfs_set_header_blocknr(&leaf->header, bh_blocknr(subvol));
        btrfs_set_header_generation(&leaf->header, trans->transid);
        memcpy(leaf->header.fsid, root->fs_info->disk_super->fsid,
               sizeof(leaf->header.fsid));
@@ -1713,7 +1713,7 @@ static int create_subvol(struct btrfs_root *root, char *name, int namelen)
        btrfs_set_inode_nblocks(inode_item, 1);
        btrfs_set_inode_mode(inode_item, S_IFDIR | 0755);
 
-       btrfs_set_root_blocknr(&root_item, subvol->b_blocknr);
+       btrfs_set_root_blocknr(&root_item, bh_blocknr(subvol));
        btrfs_set_root_refs(&root_item, 1);
 
        mark_buffer_dirty(subvol);
@@ -1803,7 +1803,7 @@ static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
        key.offset = 1;
        key.flags = 0;
        btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
-       btrfs_set_root_blocknr(&new_root_item, root->node->b_blocknr);
+       btrfs_set_root_blocknr(&new_root_item, bh_blocknr(root->node));
 
        ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
                                &new_root_item);
index e15a072..3a15943 100644 (file)
@@ -119,10 +119,10 @@ int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
 
        while(1) {
                old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
-               if (old_extent_block == extent_root->node->b_blocknr)
+               if (old_extent_block == bh_blocknr(extent_root->node))
                        break;
                btrfs_set_root_blocknr(&extent_root->root_item,
-                                      extent_root->node->b_blocknr);
+                                      bh_blocknr(extent_root->node));
                ret = btrfs_update_root(trans, tree_root,
                                        &extent_root->root_key,
                                        &extent_root->root_item);
@@ -176,7 +176,7 @@ int add_dirty_roots(struct btrfs_trans_handle *trans,
                                     (unsigned long)root->root_key.objectid,
                                     BTRFS_ROOT_TRANS_TAG);
                        if (root->commit_root == root->node) {
-                               WARN_ON(root->node->b_blocknr !=
+                               WARN_ON(bh_blocknr(root->node) !=
                                        btrfs_root_blocknr(&root->root_item));
                                brelse(root->commit_root);
                                root->commit_root = NULL;
@@ -191,7 +191,7 @@ int add_dirty_roots(struct btrfs_trans_handle *trans,
                        dirty->root = root;
                        root->root_key.offset = root->fs_info->generation;
                        btrfs_set_root_blocknr(&root->root_item,
-                                              root->node->b_blocknr);
+                                              bh_blocknr(root->node));
                        err = btrfs_insert_root(trans, root->fs_info->tree_root,
                                                &root->root_key,
                                                &root->root_item);