Btrfs: create a logical->phsyical block number mapping scheme

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

7 files changed, 134 insertions, 68 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index f31ac843bf2e..e2fc6f0d0243 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -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);
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 01310de2bf4a..454eb88611bb 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -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;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index e09233262af6..c872a7e67abd 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -10,10 +10,30 @@
 #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);
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 0ef6e6f714af..46cc5dc9d572 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -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
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index be9630df506c..d560831c10a7 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -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]);
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 2972aaa9eb7e..4ff0cc1efb13 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -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);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index e15a072407bf..3a15943ea8ed 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -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);