Btrfs: Audit callers and return codes to make sure -ENOSPC gets up the stack

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

11 files changed, 410 insertions, 215 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 498dea0854c1..606a19b5916d 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -73,6 +73,7 @@ static int btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root
 {
         struct buffer_head *cow;
         struct btrfs_node *cow_node;
+        int ret;
 
         if (btrfs_header_generation(btrfs_buffer_header(buf)) ==
                                     trans->transid) {
@@ -80,6 +81,8 @@ static int btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root
                 return 0;
         }
         cow = btrfs_alloc_free_block(trans, root, buf->b_blocknr);
+        if (IS_ERR(cow))
+                return PTR_ERR(cow);
         cow_node = btrfs_buffer_node(cow);
         if (buf->b_size != root->blocksize || cow->b_size != root->blocksize)
                 WARN_ON(1);
@@ -87,7 +90,9 @@ static int btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root
         btrfs_set_header_blocknr(&cow_node->header, bh_blocknr(cow));
         btrfs_set_header_generation(&cow_node->header, trans->transid);
         btrfs_set_header_owner(&cow_node->header, root->root_key.objectid);
-        btrfs_inc_ref(trans, root, buf);
+        ret = btrfs_inc_ref(trans, root, buf);
+        if (ret)
+                return ret;
         if (buf == root->node) {
                 root->node = cow;
                 get_bh(cow);
@@ -320,6 +325,7 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
         int wret;
         int pslot;
         int orig_slot = path->slots[level];
+        int err_on_enospc = 0;
         u64 orig_ptr;
 
         if (level == 0)
@@ -363,29 +369,43 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
             BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
                 return 0;
 
+        if (btrfs_header_nritems(&mid->header) < 2)
+                err_on_enospc = 1;
+
         left_buf = read_node_slot(root, parent_buf, pslot - 1);
         right_buf = read_node_slot(root, parent_buf, pslot + 1);
 
         /* first, try to make some room in the middle buffer */
         if (left_buf) {
-                btrfs_cow_block(trans, root, left_buf, parent_buf, pslot - 1,
-                                &left_buf);
+                wret = btrfs_cow_block(trans, root, left_buf,
+                                       parent_buf, pslot - 1, &left_buf);
+                if (wret) {
+                        ret = wret;
+                        goto enospc;
+                }
                 left = btrfs_buffer_node(left_buf);
                 orig_slot += btrfs_header_nritems(&left->header);
                 wret = push_node_left(trans, root, left_buf, mid_buf);
                 if (wret < 0)
                         ret = wret;
+                if (btrfs_header_nritems(&mid->header) < 2)
+                        err_on_enospc = 1;
         }
 
         /*
          * then try to empty the right most buffer into the middle
          */
         if (right_buf) {
-                btrfs_cow_block(trans, root, right_buf, parent_buf, pslot + 1,
-                                &right_buf);
+                wret = btrfs_cow_block(trans, root, right_buf,
+                                       parent_buf, pslot + 1, &right_buf);
+                if (wret) {
+                        ret = wret;
+                        goto enospc;
+                }
+
                 right = btrfs_buffer_node(right_buf);
                 wret = push_node_left(trans, root, mid_buf, right_buf);
-                if (wret < 0)
+                if (wret < 0 && wret != -ENOSPC)
                         ret = wret;
                 if (btrfs_header_nritems(&right->header) == 0) {
                         u64 blocknr = bh_blocknr(right_buf);
@@ -421,8 +441,10 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
                  */
                 BUG_ON(!left_buf);
                 wret = balance_node_right(trans, root, mid_buf, left_buf);
-                if (wret < 0)
+                if (wret < 0) {
                         ret = wret;
+                        goto enospc;
+                }
                 BUG_ON(wret == 1);
         }
         if (btrfs_header_nritems(&mid->header) == 0) {
@@ -467,7 +489,7 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
             btrfs_node_blockptr(btrfs_buffer_node(path->nodes[level]),
                                 path->slots[level]))
                 BUG();
-
+enospc:
         if (right_buf)
                 btrfs_block_release(root, right_buf);
         if (left_buf)
@@ -519,10 +541,15 @@ static int push_nodes_for_insert(struct btrfs_trans_handle *trans,
                 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
                         wret = 1;
                 } else {
-                        btrfs_cow_block(trans, root, left_buf, parent_buf,
-                                        pslot - 1, &left_buf);
-                        left = btrfs_buffer_node(left_buf);
-                        wret = push_node_left(trans, root, left_buf, mid_buf);
+                        ret = btrfs_cow_block(trans, root, left_buf, parent_buf,
+                                              pslot - 1, &left_buf);
+                        if (ret)
+                                wret = 1;
+                        else {
+                                left = btrfs_buffer_node(left_buf);
+                                wret = push_node_left(trans, root,
+                                                      left_buf, mid_buf);
+                        }
                 }
                 if (wret < 0)
                         ret = wret;
@@ -561,11 +588,16 @@ static int push_nodes_for_insert(struct btrfs_trans_handle *trans,
                 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
                         wret = 1;
                 } else {
-                        btrfs_cow_block(trans, root, right_buf,
-                                        parent_buf, pslot + 1, &right_buf);
-                        right = btrfs_buffer_node(right_buf);
-                        wret = balance_node_right(trans, root,
-                                                  right_buf, mid_buf);
+                        ret = btrfs_cow_block(trans, root, right_buf,
+                                              parent_buf, pslot + 1,
+                                              &right_buf);
+                        if (ret)
+                                wret = 1;
+                        else {
+                                right = btrfs_buffer_node(right_buf);
+                                wret = balance_node_right(trans, root,
+                                                          right_buf, mid_buf);
+                        }
                 }
                 if (wret < 0)
                         ret = wret;
@@ -631,6 +663,10 @@ again:
                                                p->nodes[level + 1],
                                                p->slots[level + 1],
                                                &cow_buf);
+                        if (wret) {
+                                btrfs_block_release(root, cow_buf);
+                                return wret;
+                        }
                         b = cow_buf;
                         c = btrfs_buffer_node(b);
                 }
@@ -737,6 +773,7 @@ static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root
         src_nritems = btrfs_header_nritems(&src->header);
         dst_nritems = btrfs_header_nritems(&dst->header);
         push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
+
         if (push_items <= 0) {
                 return 1;
         }
@@ -827,6 +864,8 @@ static int insert_new_root(struct btrfs_trans_handle *trans, struct btrfs_root
         BUG_ON(path->nodes[level-1] != root->node);
 
         t = btrfs_alloc_free_block(trans, root, root->node->b_blocknr);
+        if (IS_ERR(t))
+                return PTR_ERR(t);
         c = btrfs_buffer_node(t);
         memset(c, 0, root->blocksize);
         btrfs_set_header_nritems(&c->header, 1);
@@ -929,10 +968,15 @@ static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
                     btrfs_header_nritems(&c->header) <
                     BTRFS_NODEPTRS_PER_BLOCK(root) - 1)
                         return 0;
+                if (ret < 0)
+                        return ret;
         }
 
         c_nritems = btrfs_header_nritems(&c->header);
         split_buffer = btrfs_alloc_free_block(trans, root, t->b_blocknr);
+        if (IS_ERR(split_buffer))
+                return PTR_ERR(split_buffer);
+
         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));
@@ -1022,6 +1066,7 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
         struct btrfs_item *item;
         u32 left_nritems;
         u32 right_nritems;
+        int ret;
 
         slot = path->slots[1];
         if (!path->nodes[1]) {
@@ -1041,7 +1086,12 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
                 return 1;
         }
         /* cow and double check */
-        btrfs_cow_block(trans, root, right_buf, upper, slot + 1, &right_buf);
+        ret = btrfs_cow_block(trans, root, right_buf, upper,
+                              slot + 1, &right_buf);
+        if (ret) {
+                btrfs_block_release(root, right_buf);
+                return 1;
+        }
         right = btrfs_buffer_leaf(right_buf);
         free_space = btrfs_leaf_free_space(root, right);
         if (free_space < data_size + sizeof(struct btrfs_item)) {
@@ -1162,7 +1212,11 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
         }
 
         /* cow and double check */
-        btrfs_cow_block(trans, root, t, path->nodes[1], slot - 1, &t);
+        ret = btrfs_cow_block(trans, root, t, path->nodes[1], slot - 1, &t);
+        if (ret) {
+                /* we hit -ENOSPC, but it isn't fatal here */
+                return 1;
+        }
         left = btrfs_buffer_leaf(t);
         free_space = btrfs_leaf_free_space(root, left);
         if (free_space < data_size + sizeof(struct btrfs_item)) {
@@ -1309,8 +1363,11 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
         slot = path->slots[0];
         nritems = btrfs_header_nritems(&l->header);
         mid = (nritems + 1)/ 2;
+
         right_buffer = btrfs_alloc_free_block(trans, root, l_buf->b_blocknr);
-        BUG_ON(!right_buffer);
+        if (IS_ERR(right_buffer))
+                return PTR_ERR(right_buffer);
+
         right = btrfs_buffer_leaf(right_buffer);
         memset(&right->header, 0, sizeof(right->header));
         btrfs_set_header_blocknr(&right->header, bh_blocknr(right_buffer));
@@ -1407,7 +1464,9 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
         if (!double_split)
                 return ret;
         right_buffer = btrfs_alloc_free_block(trans, root, l_buf->b_blocknr);
-        BUG_ON(!right_buffer);
+        if (IS_ERR(right_buffer))
+                return PTR_ERR(right_buffer);
+
         right = btrfs_buffer_leaf(right_buffer);
         memset(&right->header, 0, sizeof(right->header));
         btrfs_set_header_blocknr(&right->header, bh_blocknr(right_buffer));
@@ -1655,7 +1714,6 @@ int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
                              ptr, data, data_size);
                 btrfs_mark_buffer_dirty(path->nodes[0]);
         }
-        btrfs_release_path(root, path);
         btrfs_free_path(path);
         return ret;
 }
@@ -1775,12 +1833,12 @@ int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                         slot = path->slots[1];
                         get_bh(leaf_buf);
                         wret = push_leaf_left(trans, root, path, 1);
-                        if (wret < 0)
+                        if (wret < 0 && wret != -ENOSPC)
                                 ret = wret;
                         if (path->nodes[0] == leaf_buf &&
                             btrfs_header_nritems(&leaf->header)) {
                                 wret = push_leaf_right(trans, root, path, 1);
-                                if (wret < 0)
+                                if (wret < 0 && wret != -ENOSPC)
                                         ret = wret;
                         }
                         if (btrfs_header_nritems(&leaf->header) == 0) {
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 19a1d998fca7..77071f273977 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1126,9 +1126,6 @@ int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root,
                           u64 objectid, u64 offset,
                           char *data, size_t len);
-int btrfs_csum_verify_file_block(struct btrfs_root *root,
-                                 u64 objectid, u64 offset,
-                                 char *data, size_t len);
 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
                                           struct btrfs_root *root,
                                           struct btrfs_path *path,
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index ff10cf5a8422..d5db8bdea3d8 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -47,6 +47,8 @@ static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
                 if (ret)
                         return ERR_PTR(ret);
         }
+        if (ret < 0)
+                return ERR_PTR(ret);
         WARN_ON(ret > 0);
         leaf = btrfs_buffer_leaf(path->nodes[0]);
         item = leaf->items + path->slots[0];
@@ -225,14 +227,13 @@ int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
         struct btrfs_leaf *leaf;
         u32 sub_item_len;
         u32 item_len;
-        int ret;
+        int ret = 0;
 
         leaf = btrfs_buffer_leaf(path->nodes[0]);
         sub_item_len = sizeof(*di) + btrfs_dir_name_len(di);
         item_len = btrfs_item_size(leaf->items + path->slots[0]);
         if (sub_item_len == btrfs_item_size(leaf->items + path->slots[0])) {
                 ret = btrfs_del_item(trans, root, path);
-                BUG_ON(ret);
         } else {
                 char *ptr = (char *)di;
                 char *start = btrfs_item_ptr(leaf, path->slots[0], char);
@@ -240,7 +241,6 @@ int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
                         item_len - (ptr + sub_item_len - start));
                 ret = btrfs_truncate_item(trans, root, path,
                                           item_len - sub_item_len);
-                BUG_ON(ret);
         }
         return 0;
 }
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 3712e946f9c8..865a284aa06c 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -580,7 +580,7 @@ int close_ctree(struct btrfs_root *root)
         btrfs_transaction_flush_work(root);
         mutex_lock(&fs_info->fs_mutex);
         trans = btrfs_start_transaction(root, 1);
-        btrfs_commit_transaction(trans, root);
+        ret = btrfs_commit_transaction(trans, root);
         /* run commit again to  drop the original snapshot */
         trans = btrfs_start_transaction(root, 1);
         btrfs_commit_transaction(trans, root);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index b38c3e92f0c8..8025e9f8ef19 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -100,6 +100,8 @@ static int cache_block_group(struct btrfs_root *root,
                 if (slot >= btrfs_header_nritems(&leaf->header)) {
                         reada_extent_leaves(root, path, limit);
                         ret = btrfs_next_leaf(root, path);
+                        if (ret < 0)
+                                goto err;
                         if (ret == 0) {
                                 continue;
                         } else {
@@ -148,6 +150,7 @@ static int cache_block_group(struct btrfs_root *root,
         }
 
         block_group->cached = 1;
+err:
         btrfs_free_path(path);
         return 0;
 }
@@ -201,7 +204,9 @@ static u64 find_search_start(struct btrfs_root *root,
                 last = max(last, cache->last_prealloc);
         }
 again:
-        cache_block_group(root, cache);
+        ret = cache_block_group(root, cache);
+        if (ret)
+                goto out;
         while(1) {
                 ret = find_first_radix_bit(&root->fs_info->extent_map_radix,
                                            gang, last, ARRAY_SIZE(gang));
@@ -398,16 +403,23 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
         struct btrfs_key ins;
         u32 refs;
 
-        find_free_extent(trans, root->fs_info->extent_root, 0, 0, (u64)-1, 0,
-                         &ins, 0);
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path)
+                return -ENOMEM;
+        ret = find_free_extent(trans, root->fs_info->extent_root, 0, 0,
+                               (u64)-1, 0, &ins, 0);
+        if (ret) {
+                btrfs_free_path(path);
+                return ret;
+        }
         key.objectid = blocknr;
         key.flags = 0;
         btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
         key.offset = num_blocks;
         ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
                                 0, 1);
+        if (ret < 0)
+                return ret;
         if (ret != 0) {
                 BUG();
         }
@@ -442,12 +454,14 @@ static int lookup_extent_ref(struct btrfs_trans_handle *trans,
         btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
         ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
                                 0, 0);
+        if (ret < 0)
+                goto out;
         if (ret != 0)
                 BUG();
         l = btrfs_buffer_leaf(path->nodes[0]);
         item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
         *refs = btrfs_extent_refs(item);
-        btrfs_release_path(root->fs_info->extent_root, path);
+out:
         btrfs_free_path(path);
         return 0;
 }
@@ -469,6 +483,8 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
         int i;
         int leaf;
         int ret;
+        int faili;
+        int err;
 
         if (!root->ref_cows)
                 return 0;
@@ -491,14 +507,45 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                                 continue;
                         ret = btrfs_inc_extent_ref(trans, root, disk_blocknr,
                                     btrfs_file_extent_disk_num_blocks(fi));
-                        BUG_ON(ret);
+                        if (ret) {
+                                faili = i;
+                                goto fail;
+                        }
                 } else {
                         blocknr = btrfs_node_blockptr(buf_node, i);
                         ret = btrfs_inc_extent_ref(trans, root, blocknr, 1);
-                        BUG_ON(ret);
+                        if (ret) {
+                                faili = i;
+                                goto fail;
+                        }
                 }
         }
         return 0;
+fail:
+        for (i =0; i < faili; i++) {
+                if (leaf) {
+                        u64 disk_blocknr;
+                        key = &buf_leaf->items[i].key;
+                        if (btrfs_disk_key_type(key) != BTRFS_EXTENT_DATA_KEY)
+                                continue;
+                        fi = btrfs_item_ptr(buf_leaf, i,
+                                            struct btrfs_file_extent_item);
+                        if (btrfs_file_extent_type(fi) ==
+                            BTRFS_FILE_EXTENT_INLINE)
+                                continue;
+                        disk_blocknr = btrfs_file_extent_disk_blocknr(fi);
+                        if (disk_blocknr == 0)
+                                continue;
+                        err = btrfs_free_extent(trans, root, disk_blocknr,
+                                    btrfs_file_extent_disk_num_blocks(fi), 0);
+                        BUG_ON(err);
+                } else {
+                        blocknr = btrfs_node_blockptr(buf_node, i);
+                        err = btrfs_free_extent(trans, root, blocknr, 1, 0);
+                        BUG_ON(err);
+                }
+        }
+        return ret;
 }
 
 static int write_one_cache_group(struct btrfs_trans_handle *trans,
@@ -512,15 +559,20 @@ static int write_one_cache_group(struct btrfs_trans_handle *trans,
         struct btrfs_block_group_item *bi;
         struct btrfs_key ins;
 
-        find_free_extent(trans, extent_root, 0, 0, (u64)-1, 0, &ins, 0);
+        ret = find_free_extent(trans, extent_root, 0, 0, (u64)-1, 0, &ins, 0);
+        /* FIXME, set bit to recalc cache groups on next mount */
+        if (ret)
+                return ret;
         ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
+        if (ret < 0)
+                goto fail;
         BUG_ON(ret);
         bi = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
                             struct btrfs_block_group_item);
         memcpy(bi, &cache->item, sizeof(*bi));
         mark_buffer_dirty(path->nodes[0]);
         btrfs_release_path(extent_root, path);
-
+fail:
         finish_current_insert(trans, extent_root);
         pending_ret = del_pending_extents(trans, extent_root);
         if (ret)
@@ -543,6 +595,7 @@ static int write_dirty_block_radix(struct btrfs_trans_handle *trans,
         int werr = 0;
         int i;
         struct btrfs_path *path;
+        unsigned long off = 0;
 
         path = btrfs_alloc_path();
         if (!path)
@@ -550,18 +603,28 @@ static int write_dirty_block_radix(struct btrfs_trans_handle *trans,
 
         while(1) {
                 ret = radix_tree_gang_lookup_tag(radix, (void **)cache,
-                                                 0, ARRAY_SIZE(cache),
+                                                 off, ARRAY_SIZE(cache),
                                                  BTRFS_BLOCK_GROUP_DIRTY);
                 if (!ret)
                         break;
                 for (i = 0; i < ret; i++) {
-                        radix_tree_tag_clear(radix, cache[i]->key.objectid +
-                                             cache[i]->key.offset - 1,
-                                             BTRFS_BLOCK_GROUP_DIRTY);
                         err = write_one_cache_group(trans, root,
                                                     path, cache[i]);
-                        if (err)
+                        /*
+                         * if we fail to write the cache group, we want
+                         * to keep it marked dirty in hopes that a later
+                         * write will work
+                         */
+                        if (err) {
                                 werr = err;
+                                off = cache[i]->key.objectid +
+                                        cache[i]->key.offset;
+                                continue;
+                        }
+
+                        radix_tree_tag_clear(radix, cache[i]->key.objectid +
+                                             cache[i]->key.offset - 1,
+                                             BTRFS_BLOCK_GROUP_DIRTY);
                 }
         }
         btrfs_free_path(path);
@@ -801,14 +864,20 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
         btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
         key.offset = num_blocks;
 
-        find_free_extent(trans, root, 0, 0, (u64)-1, 0, &ins, 0);
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path)
+                return -ENOMEM;
 
-        ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
+        ret = find_free_extent(trans, root, 0, 0, (u64)-1, 0, &ins, 0);
         if (ret) {
-                BUG();
+                btrfs_free_path(path);
+                return ret;
         }
+
+        ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
+        if (ret < 0)
+                return ret;
+        BUG_ON(ret);
         ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
                             struct btrfs_extent_item);
         BUG_ON(ei->refs == 0);
@@ -827,8 +896,9 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
                 btrfs_set_super_blocks_used(info->disk_super,
                                             super_blocks_used - num_blocks);
                 ret = btrfs_del_item(trans, extent_root, path);
-                if (ret)
-                        BUG();
+                if (ret) {
+                        return ret;
+                }
                 ret = update_block_group(trans, root, blocknr, num_blocks, 0,
                                          mark_free, 0);
                 BUG_ON(ret);
@@ -1075,7 +1145,6 @@ next:
                 path->slots[0]++;
                 cond_resched();
         }
-        // FIXME -ENOSPC
 check_pending:
         /* we have to make sure we didn't find an extent that has already
          * been allocated by the map tree or the original allocation
@@ -1246,7 +1315,15 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
         ret = find_free_extent(trans, root, num_blocks, search_start,
                                search_end, hint_block, ins, data);
         if (ret) {
-                return ret;
+                if (search_start == 0)
+                        return ret;
+                search_end = search_start - 1;
+                search_start = 0;
+                hint_block = search_start;
+                ret = find_free_extent(trans, root, num_blocks, search_start,
+                                       search_end, hint_block, ins, data);
+                if (ret)
+                        return ret;
         }
 
         /*
@@ -1271,7 +1348,16 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
                                        search_end, hint_block,
                                        &prealloc_key, 0);
                 if (ret) {
-                        return ret;
+                        if (search_start == 0)
+                                return ret;
+                        search_end = search_start - 1;
+                        search_start = 0;
+                        hint_block = search_start;
+                        ret = find_free_extent(trans, root, 0, search_start,
+                                               search_end, hint_block,
+                                               &prealloc_key, 0);
+                        if (ret)
+                                return ret;
                 }
         }
 
@@ -1309,11 +1395,14 @@ struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
         ret = btrfs_alloc_extent(trans, root, root->root_key.objectid,
                                  1, hint, (unsigned long)-1, &ins, 0);
         if (ret) {
-                BUG();
-                return NULL;
+                BUG_ON(ret > 0);
+                return ERR_PTR(ret);
         }
-        BUG_ON(ret);
         buf = btrfs_find_create_tree_block(root, ins.objectid);
+        if (!buf) {
+                btrfs_free_extent(trans, root, ins.objectid, 1, 0);
+                return ERR_PTR(-ENOMEM);
+        }
         set_buffer_uptodate(buf);
         set_buffer_checked(buf);
         set_radix_bit(&trans->transaction->dirty_pages, buf->b_page->index);
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index cf894f09f6c7..68859934ae25 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -45,6 +45,8 @@ int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
 
         ret = btrfs_insert_empty_item(trans, root, path, &file_key,
                                       sizeof(*item));
+        if (ret < 0)
+                goto out;
         BUG_ON(ret);
         item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
                               struct btrfs_file_extent_item);
@@ -55,10 +57,9 @@ int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
         btrfs_set_file_extent_generation(item, trans->transid);
         btrfs_set_file_extent_type(item, BTRFS_FILE_EXTENT_REG);
         btrfs_mark_buffer_dirty(path->nodes[0]);
-
-        btrfs_release_path(root, path);
+out:
         btrfs_free_path(path);
-        return 0;
+        return ret;
 }
 
 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
@@ -213,6 +214,8 @@ insert:
         csum_offset = 0;
         ret = btrfs_insert_empty_item(trans, root, path, &file_key,
                                       BTRFS_CRC32_SIZE);
+        if (ret < 0)
+                goto fail;
         if (ret != 0) {
                 WARN_ON(1);
                 goto fail;
@@ -261,40 +264,3 @@ int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
         return ret;
 }
 
-int btrfs_csum_verify_file_block(struct btrfs_root *root,
-                                 u64 objectid, u64 offset,
-                                 char *data, size_t len)
-{
-        int ret;
-        struct btrfs_key file_key;
-        struct btrfs_path *path;
-        struct btrfs_csum_item *item;
-        char result[BTRFS_CRC32_SIZE];
-
-        path = btrfs_alloc_path();
-        BUG_ON(!path);
-        file_key.objectid = objectid;
-        file_key.offset = offset;
-        file_key.flags = 0;
-        btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
-        mutex_lock(&root->fs_info->fs_mutex);
-
-        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 = -ENOENT;
-                goto fail;
-        }
-
-        ret = btrfs_csum_data(root, data, len, result);
-        WARN_ON(ret);
-        if (memcmp(result, &item->csum, BTRFS_CRC32_SIZE))
-                ret = 1;
-fail:
-        btrfs_release_path(root, path);
-        btrfs_free_path(path);
-        mutex_unlock(&root->fs_info->fs_mutex);
-        return ret;
-}
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 23f029359688..fef7ba1e707f 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -81,6 +81,62 @@ static void btrfs_drop_pages(struct page **pages, size_t num_pages)
         }
 }
 
+static int insert_inline_extent(struct btrfs_root *root, struct inode *inode,
+                                u64 offset, ssize_t size,
+                                struct buffer_head *bh)
+{
+        struct btrfs_key key;
+        struct btrfs_path *path;
+        char *ptr, *kaddr;
+        struct btrfs_trans_handle *trans;
+        struct btrfs_file_extent_item *ei;
+        u32 datasize;
+        int err = 0;
+        int ret;
+
+        path = btrfs_alloc_path();
+        if (!path)
+                return -ENOMEM;
+
+        mutex_lock(&root->fs_info->fs_mutex);
+        trans = btrfs_start_transaction(root, 1);
+        btrfs_set_trans_block_group(trans, inode);
+
+        key.objectid = inode->i_ino;
+        key.offset = offset;
+        key.flags = 0;
+        btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
+        BUG_ON(size >= PAGE_CACHE_SIZE);
+        datasize = btrfs_file_extent_calc_inline_size(size);
+
+        ret = btrfs_insert_empty_item(trans, root, path, &key,
+                                      datasize);
+        if (ret) {
+                err = ret;
+                goto fail;
+        }
+        ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
+               path->slots[0], struct btrfs_file_extent_item);
+        btrfs_set_file_extent_generation(ei, trans->transid);
+        btrfs_set_file_extent_type(ei,
+                                   BTRFS_FILE_EXTENT_INLINE);
+        ptr = btrfs_file_extent_inline_start(ei);
+
+        kaddr = kmap_atomic(bh->b_page, KM_USER0);
+        btrfs_memcpy(root, path->nodes[0]->b_data,
+                     ptr, kaddr + bh_offset(bh),
+                     size);
+        kunmap_atomic(kaddr, KM_USER0);
+        mark_buffer_dirty(path->nodes[0]);
+fail:
+        btrfs_free_path(path);
+        ret = btrfs_end_transaction(trans, root);
+        if (ret && !err)
+                err = ret;
+        mutex_unlock(&root->fs_info->fs_mutex);
+        return err;
+}
+
 static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
                                    struct btrfs_root *root,
                                    struct file *file,
@@ -96,57 +152,22 @@ static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
         int this_write;
         struct inode *inode = file->f_path.dentry->d_inode;
         struct buffer_head *bh;
-        struct btrfs_file_extent_item *ei;
 
         for (i = 0; i < num_pages; i++) {
                 offset = pos & (PAGE_CACHE_SIZE -1);
                 this_write = min((size_t)PAGE_CACHE_SIZE - offset, write_bytes);
-                /* FIXME, one block at a time */
 
+                /* FIXME, one block at a time */
                 bh = page_buffers(pages[i]);
 
                 if (buffer_mapped(bh) && bh->b_blocknr == 0) {
-                        struct btrfs_key key;
-                        struct btrfs_path *path;
-                        char *ptr, *kaddr;
-                        u32 datasize;
-
-                        mutex_lock(&root->fs_info->fs_mutex);
-                        trans = btrfs_start_transaction(root, 1);
-                        btrfs_set_trans_block_group(trans, inode);
-
-                        /* create an inline extent, and copy the data in */
-                        path = btrfs_alloc_path();
-                        BUG_ON(!path);
-                        key.objectid = inode->i_ino;
-                        key.offset = pages[i]->index << PAGE_CACHE_SHIFT;
-                        key.flags = 0;
-                        btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
-                        BUG_ON(write_bytes >= PAGE_CACHE_SIZE);
-                        datasize = offset +
-                                btrfs_file_extent_calc_inline_size(write_bytes);
-
-                        ret = btrfs_insert_empty_item(trans, root, path, &key,
-                                                      datasize);
-                        BUG_ON(ret);
-                        ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
-                               path->slots[0], struct btrfs_file_extent_item);
-                        btrfs_set_file_extent_generation(ei, trans->transid);
-                        btrfs_set_file_extent_type(ei,
-                                                   BTRFS_FILE_EXTENT_INLINE);
-                        ptr = btrfs_file_extent_inline_start(ei);
-
-                        kaddr = kmap_atomic(bh->b_page, KM_USER0);
-                        btrfs_memcpy(root, path->nodes[0]->b_data,
-                                     ptr, kaddr + bh_offset(bh),
-                                     offset + write_bytes);
-                        kunmap_atomic(kaddr, KM_USER0);
-
-                        mark_buffer_dirty(path->nodes[0]);
-                        btrfs_free_path(path);
-                        ret = btrfs_end_transaction(trans, root);
-                        BUG_ON(ret);
-                        mutex_unlock(&root->fs_info->fs_mutex);
+                        ret = insert_inline_extent(root, inode,
+                                        pages[i]->index << PAGE_CACHE_SHIFT,
+                                        offset + this_write, bh);
+                        if (ret) {
+                                err = ret;
+                                goto failed;
+                        }
                 }
 
                 ret = btrfs_commit_write(file, pages[i], offset,
@@ -321,6 +342,7 @@ next_slot:
                                         btrfs_file_extent_disk_blocknr(extent);
                         }
                         ret = btrfs_del_item(trans, root, path);
+                        /* TODO update progress marker and return */
                         BUG_ON(ret);
                         btrfs_release_path(root, path);
                         extent = NULL;
@@ -452,7 +474,8 @@ static int prepare_pages(struct btrfs_root *root,
                 err = btrfs_drop_extents(trans, root, inode,
                          start_pos, (pos + write_bytes + root->blocksize -1) &
                          ~((u64)root->blocksize - 1), &hint_block);
-                BUG_ON(err);
+                if (err)
+                        goto failed_release;
         }
 
         /* insert any holes we need to create */
@@ -469,7 +492,8 @@ static int prepare_pages(struct btrfs_root *root,
                                                        last_pos_in_file,
                                                        0, 0, hole_size);
                 }
-                BUG_ON(err);
+                if (err)
+                        goto failed_release;
         }
 
         /*
@@ -481,11 +505,13 @@ static int prepare_pages(struct btrfs_root *root,
                 err = btrfs_alloc_extent(trans, root, inode->i_ino,
                                          num_blocks, hint_block, (u64)-1,
                                          &ins, 1);
-                BUG_ON(err);
+                if (err)
+                        goto failed_truncate;
                 err = btrfs_insert_file_extent(trans, root, inode->i_ino,
                                        start_pos, ins.objectid, ins.offset,
                                        ins.offset);
-                BUG_ON(err);
+                if (err)
+                        goto failed_truncate;
         } else {
                 ins.offset = 0;
                 ins.objectid = 0;
@@ -618,16 +644,21 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                 ret = prepare_pages(root, file, pages, num_pages,
                                     pos, first_index, last_index,
                                     write_bytes);
-                BUG_ON(ret);
+                if (ret)
+                        goto out;
 
                 ret = btrfs_copy_from_user(pos, num_pages,
                                            write_bytes, pages, buf);
-                BUG_ON(ret);
+                if (ret) {
+                        btrfs_drop_pages(pages, num_pages);
+                        goto out;
+                }
 
                 ret = dirty_and_release_pages(NULL, root, file, pages,
                                               num_pages, pos, write_bytes);
-                BUG_ON(ret);
                 btrfs_drop_pages(pages, num_pages);
+                if (ret)
+                        goto out;
 
                 buf += write_bytes;
                 count -= write_bytes;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 94f1c28c25b9..6d031daa7779 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -212,7 +212,11 @@ static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
         struct btrfs_dir_item *di;
 
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path) {
+                ret = -ENOMEM;
+                goto err;
+        }
+
         di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
                                     name, name_len, -1);
         if (IS_ERR(di)) {
@@ -225,7 +229,8 @@ static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
         }
         objectid = btrfs_disk_key_objectid(&di->location);
         ret = btrfs_delete_one_dir_name(trans, root, path, di);
-        BUG_ON(ret);
+        if (ret)
+                goto err;
         btrfs_release_path(root, path);
 
         di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
@@ -239,7 +244,6 @@ static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
                 goto err;
         }
         ret = btrfs_delete_one_dir_name(trans, root, path, di);
-        BUG_ON(ret);
 
         dentry->d_inode->i_ctime = dir->i_ctime;
 err:
@@ -248,7 +252,7 @@ err:
                 dir->i_size -= name_len * 2;
                 btrfs_update_inode(trans, root, dir);
                 drop_nlink(dentry->d_inode);
-                btrfs_update_inode(trans, root, dentry->d_inode);
+                ret = btrfs_update_inode(trans, root, dentry->d_inode);
                 dir->i_sb->s_dirt = 1;
         }
         return ret;
@@ -359,9 +363,10 @@ static int btrfs_free_inode(struct btrfs_trans_handle *trans,
         BUG_ON(!path);
         ret = btrfs_lookup_inode(trans, root, path,
                                  &BTRFS_I(inode)->location, -1);
-        BUG_ON(ret);
-        ret = btrfs_del_item(trans, root, path);
-        BUG_ON(ret);
+        if (ret > 0)
+                ret = -ENOENT;
+        if (!ret)
+                ret = btrfs_del_item(trans, root, path);
         btrfs_free_path(path);
         return ret;
 }
@@ -516,7 +521,8 @@ static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
                 }
                 if (del_item) {
                         ret = btrfs_del_item(trans, root, path);
-                        BUG_ON(ret);
+                        if (ret)
+                                goto error;
                 } else {
                         break;
                 }
@@ -577,19 +583,22 @@ static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
                                  page->index << PAGE_CACHE_SHIFT,
                                  (page->index + 1) << PAGE_CACHE_SHIFT,
                                  &alloc_hint);
-        BUG_ON(ret);
+        if (ret)
+                goto out;
         ret = btrfs_alloc_extent(trans, root, inode->i_ino, 1,
                                  alloc_hint, (u64)-1, &ins, 1);
-        BUG_ON(ret);
+        if (ret)
+                goto out;
         ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
                                        page->index << PAGE_CACHE_SHIFT,
                                        ins.objectid, 1, 1);
-        BUG_ON(ret);
+        if (ret)
+                goto out;
         SetPageChecked(page);
         kaddr = kmap(page);
         memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
         flush_dcache_page(page);
-        btrfs_csum_file_block(trans, root, inode->i_ino,
+        ret = btrfs_csum_file_block(trans, root, inode->i_ino,
                               page->index << PAGE_CACHE_SHIFT,
                               kaddr, PAGE_CACHE_SIZE);
         kunmap(page);
@@ -633,9 +642,10 @@ static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
                 btrfs_set_trans_block_group(trans, inode);
                 err = btrfs_insert_file_extent(trans, root, inode->i_ino,
                                                pos, 0, 0, hole_size);
-                BUG_ON(err);
                 btrfs_end_transaction(trans, root);
                 mutex_unlock(&root->fs_info->fs_mutex);
+                if (err)
+                        return err;
         }
 out:
         err = inode_setattr(inode, attr);
@@ -657,12 +667,20 @@ void btrfs_delete_inode(struct inode *inode)
         trans = btrfs_start_transaction(root, 1);
         btrfs_set_trans_block_group(trans, inode);
         ret = btrfs_truncate_in_trans(trans, root, inode);
-        BUG_ON(ret);
-        btrfs_free_inode(trans, root, inode);
+        if (ret)
+                goto no_delete_lock;
+        ret = btrfs_free_inode(trans, root, inode);
+        if (ret)
+                goto no_delete_lock;
         btrfs_end_transaction(trans, root);
         mutex_unlock(&root->fs_info->fs_mutex);
         btrfs_btree_balance_dirty(root);
         return;
+
+no_delete_lock:
+        btrfs_end_transaction(trans, root);
+        mutex_unlock(&root->fs_info->fs_mutex);
+        btrfs_btree_balance_dirty(root);
 no_delete:
         clear_inode(inode);
 }
@@ -946,7 +964,7 @@ int btrfs_write_inode(struct inode *inode, int wait)
 }
 
 /*
- * This is somewhat expense, updating the tree every time the
+ * This is somewhat expensive, updating the tree every time the
  * inode changes.  But, it is most likely to find the inode in cache.
  * FIXME, needs more benchmarking...there are no reasons other than performance
  * to keep or drop this code.
@@ -1002,8 +1020,8 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
         btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
 
         ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
-        BUG_ON(ret);
-
+        if (ret)
+                return ERR_PTR(ret);
         insert_inode_hash(inode);
         return inode;
 }
@@ -1121,7 +1139,9 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
                 drop_inode = 1;
         dir->i_sb->s_dirt = 1;
         btrfs_update_inode_block_group(trans, dir);
-        btrfs_update_inode(trans, root, inode);
+        err = btrfs_update_inode(trans, root, inode);
+        if (err)
+                drop_inode = 1;
 
         btrfs_end_transaction(trans, root);
         mutex_unlock(&root->fs_info->fs_mutex);
@@ -1349,17 +1369,26 @@ not_found:
                 ret = btrfs_alloc_extent(trans, root, inode->i_ino,
                                          1, alloc_hint, (u64)-1,
                                          &ins, 1);
-                BUG_ON(ret);
+                if (ret) {
+                        err = ret;
+                        goto out;
+                }
                 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
                                                iblock << inode->i_blkbits,
                                                ins.objectid, ins.offset,
                                                ins.offset);
-                BUG_ON(ret);
+                if (ret) {
+                        err = ret;
+                        goto out;
+                }
                 btrfs_map_bh_to_logical(root, result, ins.objectid);
         }
 out:
-        if (trans)
-                err = btrfs_end_transaction(trans, root);
+        if (trans) {
+                ret = btrfs_end_transaction(trans, root);
+                if (!err)
+                        err = ret;
+        }
         btrfs_free_path(path);
         return err;
 }
@@ -1375,8 +1404,8 @@ int btrfs_get_block(struct inode *inode, sector_t iblock,
         return err;
 }
 
-int btrfs_get_block_csum(struct inode *inode, sector_t iblock,
-                    struct buffer_head *result, int create)
+static int btrfs_get_block_csum(struct inode *inode, sector_t iblock,
+                                struct buffer_head *result, int create)
 {
         int ret;
         struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -1397,7 +1426,7 @@ int btrfs_get_block_csum(struct inode *inode, sector_t iblock,
                 /* a csum that isn't present is a preallocated region. */
                 if (ret == -ENOENT || ret == -EFBIG)
                         ret = 0;
-                result->b_private = 0;
+                result->b_private = NULL;
                 goto out;
         }
         memcpy((char *)&result->b_private, &item->csum, BTRFS_CRC32_SIZE);
@@ -1736,11 +1765,10 @@ static int __btrfs_write_full_page(struct inode *inode, struct page *page,
                         trans = btrfs_start_transaction(root, 1);
                         btrfs_set_trans_block_group(trans, inode);
                         kaddr = kmap(page);
-                        ret = btrfs_csum_file_block(trans, root, inode->i_ino,
+                        btrfs_csum_file_block(trans, root, inode->i_ino,
                                                     off, kaddr + bh_offset(bh),
                                                     bh->b_size);
                         kunmap(page);
-                        BUG_ON(ret);
                         ret = btrfs_end_transaction(trans, root);
                         BUG_ON(ret);
                         mutex_unlock(&root->fs_info->fs_mutex);
@@ -1930,7 +1958,6 @@ static void btrfs_truncate(struct inode *inode)
 
         /* FIXME, add redo link to tree so we don't leak on crash */
         ret = btrfs_truncate_in_trans(trans, root, inode);
-        BUG_ON(ret);
         btrfs_update_inode(trans, root, inode);
         ret = btrfs_end_transaction(trans, root);
         BUG_ON(ret);
@@ -1970,6 +1997,7 @@ static int create_subvol(struct btrfs_root *root, char *name, int namelen)
         struct inode *inode;
         struct inode *dir;
         int ret;
+        int err;
         u64 objectid;
         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 
@@ -1978,8 +2006,8 @@ static int create_subvol(struct btrfs_root *root, char *name, int namelen)
         BUG_ON(!trans);
 
         subvol = btrfs_alloc_free_block(trans, root, 0);
-        if (subvol == NULL)
-                return -ENOSPC;
+        if (IS_ERR(subvol))
+                return PTR_ERR(subvol);
         leaf = btrfs_buffer_leaf(subvol);
         btrfs_set_header_nritems(&leaf->header, 0);
         btrfs_set_header_level(&leaf->header, 0);
@@ -2005,7 +2033,8 @@ static int create_subvol(struct btrfs_root *root, char *name, int namelen)
 
         ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
                                        0, &objectid);
-        BUG_ON(ret);
+        if (ret)
+                goto fail;
 
         btrfs_set_root_dirid(&root_item, new_dirid);
 
@@ -2015,7 +2044,8 @@ static int create_subvol(struct btrfs_root *root, char *name, int namelen)
         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
                                 &root_item);
-        BUG_ON(ret);
+        if (ret)
+                goto fail;
 
         /*
          * insert the directory item
@@ -2025,10 +2055,12 @@ static int create_subvol(struct btrfs_root *root, char *name, int namelen)
         ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
                                     name, namelen, dir->i_ino, &key,
                                     BTRFS_FT_DIR);
-        BUG_ON(ret);
+        if (ret)
+                goto fail;
 
         ret = btrfs_commit_transaction(trans, root);
-        BUG_ON(ret);
+        if (ret)
+                goto fail_commit;
 
         new_root = btrfs_read_fs_root(root->fs_info, &key);
         BUG_ON(!new_root);
@@ -2038,24 +2070,29 @@ static int create_subvol(struct btrfs_root *root, char *name, int namelen)
 
         inode = btrfs_new_inode(trans, new_root, new_dirid,
                                 BTRFS_I(dir)->block_group, S_IFDIR | 0700);
+        if (IS_ERR(inode))
+                goto fail;
         inode->i_op = &btrfs_dir_inode_operations;
         inode->i_fop = &btrfs_dir_file_operations;
         new_root->inode = inode;
 
         ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
-        BUG_ON(ret);
+        if (ret)
+                goto fail;
 
         inode->i_nlink = 1;
         inode->i_size = 6;
         ret = btrfs_update_inode(trans, new_root, inode);
-        BUG_ON(ret);
-
-        ret = btrfs_commit_transaction(trans, new_root);
-        BUG_ON(ret);
-
+        if (ret)
+                goto fail;
+fail:
+        err = btrfs_commit_transaction(trans, root);
+        if (err && !ret)
+                ret = err;
+fail_commit:
         mutex_unlock(&root->fs_info->fs_mutex);
         btrfs_btree_balance_dirty(root);
-        return 0;
+        return ret;
 }
 
 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
@@ -2064,6 +2101,7 @@ static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
         struct btrfs_key key;
         struct btrfs_root_item new_root_item;
         int ret;
+        int err;
         u64 objectid;
 
         if (!root->ref_cows)
@@ -2074,11 +2112,13 @@ static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
         BUG_ON(!trans);
 
         ret = btrfs_update_inode(trans, root, root->inode);
-        BUG_ON(ret);
+        if (ret)
+                goto fail;
 
         ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
                                        0, &objectid);
-        BUG_ON(ret);
+        if (ret)
+                goto fail;
 
         memcpy(&new_root_item, &root->root_item,
                sizeof(new_root_item));
@@ -2091,7 +2131,8 @@ static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
 
         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
                                 &new_root_item);
-        BUG_ON(ret);
+        if (ret)
+                goto fail;
 
         /*
          * insert the directory item
@@ -2102,16 +2143,20 @@ static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
                                     root->fs_info->sb->s_root->d_inode->i_ino,
                                     &key, BTRFS_FT_DIR);
 
-        BUG_ON(ret);
+        if (ret)
+                goto fail;
 
         ret = btrfs_inc_root_ref(trans, root);
-        BUG_ON(ret);
+        if (ret)
+                goto fail;
 
-        ret = btrfs_commit_transaction(trans, root);
-        BUG_ON(ret);
+fail:
+        err = btrfs_commit_transaction(trans, root);
+        if (err && !ret)
+                ret = err;
         mutex_unlock(&root->fs_info->fs_mutex);
         btrfs_btree_balance_dirty(root);
-        return 0;
+        return ret;
 }
 
 int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int
@@ -2148,12 +2193,13 @@ int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int
                 btrfs_free_path(path);
                 if (di && !IS_ERR(di))
                         return -EEXIST;
+                if (IS_ERR(di))
+                        return PTR_ERR(di);
 
                 if (root == root->fs_info->tree_root)
                         ret = create_subvol(root, vol_args.name, namelen);
                 else
                         ret = create_snapshot(root, vol_args.name, namelen);
-                WARN_ON(ret);
                 break;
         default:
                 return -ENOTTY;
@@ -2316,7 +2362,6 @@ static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
                 old_parent_oid = btrfs_disk_key_objectid(&di->location);
                 ret = btrfs_del_item(trans, root, path);
                 if (ret) {
-                        ret = -EIO;
                         goto out_fail;
                 }
                 btrfs_release_path(root, path);
@@ -2335,7 +2380,6 @@ static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
                 }
                 ret = btrfs_del_item(trans, root, path);
                 if (ret) {
-                        ret = -EIO;
                         goto out_fail;
                 }
                 btrfs_release_path(root, path);
@@ -2361,7 +2405,9 @@ static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
                         clear_nlink(new_inode);
                 else
                         drop_nlink(new_inode);
-                btrfs_update_inode(trans, root, new_inode);
+                ret = btrfs_update_inode(trans, root, new_inode);
+                if (ret)
+                        goto out_fail;
         }
         ret = btrfs_add_link(trans, new_dentry, old_inode);
         if (ret)
@@ -2433,7 +2479,10 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
         datasize = btrfs_file_extent_calc_inline_size(name_len);
         err = btrfs_insert_empty_item(trans, root, path, &key,
                                       datasize);
-        BUG_ON(err);
+        if (err) {
+                drop_inode = 1;
+                goto out_unlock;
+        }
         ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
                path->slots[0], struct btrfs_file_extent_item);
         btrfs_set_file_extent_generation(ei, trans->transid);
@@ -2447,13 +2496,13 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
         inode->i_op = &btrfs_symlink_inode_operations;
         inode->i_mapping->a_ops = &btrfs_symlink_aops;
         inode->i_size = name_len - 1;
-        btrfs_update_inode(trans, root, inode);
-        err = 0;
+        err = btrfs_update_inode(trans, root, inode);
+        if (err)
+                drop_inode = 1;
 
 out_unlock:
         btrfs_end_transaction(trans, root);
         mutex_unlock(&root->fs_info->fs_mutex);
-
         if (drop_inode) {
                 inode_dec_link_count(inode);
                 iput(inode);
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 8e1b9046d5ec..ac0fae7780ff 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -90,7 +90,6 @@ int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
 {
         int ret;
         ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
-        BUG_ON(ret);
         return ret;
 }
 
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index ef8ad18b275c..c11ecf500202 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -125,9 +125,8 @@ static int btrfs_sync_fs(struct super_block *sb, int wait)
         trans = btrfs_start_transaction(root, 1);
         ret = btrfs_commit_transaction(trans, root);
         sb->s_dirt = 0;
-        BUG_ON(ret);
         mutex_unlock(&root->fs_info->fs_mutex);
-        return 0;
+        return ret;
 }
 
 static void btrfs_write_super(struct super_block *sb)
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index b5b99a85763f..321f8852755b 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -219,7 +219,8 @@ static int add_dirty_roots(struct btrfs_trans_handle *trans,
         struct btrfs_root *root;
         int i;
         int ret;
-        int err;
+        int err = 0;
+
         while(1) {
                 ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
                                                  ARRAY_SIZE(gang),
@@ -251,11 +252,12 @@ static int add_dirty_roots(struct btrfs_trans_handle *trans,
                         err = btrfs_insert_root(trans, root->fs_info->tree_root,
                                                 &root->root_key,
                                                 &root->root_item);
-                        BUG_ON(err);
+                        if (err)
+                                break;
                         list_add(&dirty->list, list);
                 }
         }
-        return 0;
+        return err;
 }
 
 static int drop_dirty_roots(struct btrfs_root *tree_root,
@@ -263,7 +265,7 @@ static int drop_dirty_roots(struct btrfs_root *tree_root,
 {
         struct dirty_root *dirty;
         struct btrfs_trans_handle *trans;
-        int ret;
+        int ret = 0;
         while(!list_empty(list)) {
                 mutex_lock(&tree_root->fs_info->fs_mutex);
                 dirty = list_entry(list->next, struct dirty_root, list);
@@ -274,14 +276,15 @@ static int drop_dirty_roots(struct btrfs_root *tree_root,
                 BUG_ON(ret);
 
                 ret = btrfs_del_root(trans, tree_root, &dirty->snap_key);
-                BUG_ON(ret);
+                if (ret)
+                        break;
                 ret = btrfs_end_transaction(trans, tree_root);
                 BUG_ON(ret);
                 kfree(dirty);
                 mutex_unlock(&tree_root->fs_info->fs_mutex);
                 btrfs_btree_balance_dirty(tree_root);
         }
-        return 0;
+        return ret;
 }
 
 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
@@ -321,9 +324,13 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         }
         finish_wait(&trans->transaction->writer_wait, &wait);
         WARN_ON(cur_trans != trans->transaction);
-        add_dirty_roots(trans, &root->fs_info->fs_roots_radix, &dirty_fs_roots);
+        ret = add_dirty_roots(trans, &root->fs_info->fs_roots_radix,
+                              &dirty_fs_roots);
+        BUG_ON(ret);
+
         ret = btrfs_commit_tree_roots(trans, root);
         BUG_ON(ret);
+
         cur_trans = root->fs_info->running_transaction;
         root->fs_info->running_transaction = NULL;
         if (cur_trans->list.prev != &root->fs_info->trans_list) {