Btrfs: cleanup some BUG_ON()

This patch changes some BUG_ON() to the error return.
(but, most callers still use BUG_ON())

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

9 files changed, 54 insertions, 23 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 465b5d7d6b48..4edcbe915736 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -3709,7 +3709,8 @@ int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
         unsigned long ptr;
 
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path)
+                return -ENOMEM;
         ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
         if (!ret) {
                 leaf = path->nodes[0];
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 9f31e110b481..00cbb41af660 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1248,7 +1248,10 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
                      root, fs_info, location->objectid);
 
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path) {
+                kfree(root);
+                return ERR_PTR(-ENOMEM);
+        }
         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
         if (ret == 0) {
                 l = path->nodes[0];
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 86ea471d3801..a6a8159c5d1e 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5463,7 +5463,8 @@ static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
         size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
 
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path)
+                return -ENOMEM;
 
         path->leave_spinning = 1;
         ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
@@ -6457,10 +6458,14 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
         BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
 
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path)
+                return -ENOMEM;
 
         wc = kzalloc(sizeof(*wc), GFP_NOFS);
-        BUG_ON(!wc);
+        if (!wc) {
+                btrfs_free_path(path);
+                return -ENOMEM;
+        }
 
         btrfs_assert_tree_locked(parent);
         parent_level = btrfs_header_level(parent);
@@ -6918,7 +6923,11 @@ static noinline int get_new_locations(struct inode *reloc_inode,
         }
 
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path) {
+                if (exts != *extents)
+                        kfree(exts);
+                return -ENOMEM;
+        }
 
         cur_pos = extent_key->objectid - offset;
         last_byte = extent_key->objectid + extent_key->offset;
@@ -7442,7 +7451,8 @@ static noinline int replace_extents_in_leaf(struct btrfs_trans_handle *trans,
         int ret;
 
         new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
-        BUG_ON(!new_extent);
+        if (!new_extent)
+                return -ENOMEM;
 
         ref = btrfs_lookup_leaf_ref(root, leaf->start);
         BUG_ON(!ref);
@@ -7647,7 +7657,8 @@ static noinline int init_reloc_tree(struct btrfs_trans_handle *trans,
                 return 0;
 
         root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
-        BUG_ON(!root_item);
+        if (!root_item)
+                return -ENOMEM;
 
         ret = btrfs_copy_root(trans, root, root->commit_root,
                               &eb, BTRFS_TREE_RELOC_OBJECTID);
@@ -7673,7 +7684,7 @@ static noinline int init_reloc_tree(struct btrfs_trans_handle *trans,
 
         reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
                                                  &root_key);
-        BUG_ON(!reloc_root);
+        BUG_ON(IS_ERR(reloc_root));
         reloc_root->last_trans = trans->transid;
         reloc_root->commit_root = NULL;
         reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 4f19a3e1bf32..a2134195a85e 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -48,7 +48,8 @@ int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
         struct extent_buffer *leaf;
 
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path)
+                return -ENOMEM;
         file_key.objectid = objectid;
         file_key.offset = pos;
         btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
index c56eb5909172..c05a08f4c411 100644
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -30,7 +30,8 @@ int btrfs_find_highest_inode(struct btrfs_root *root, u64 *objectid)
         int slot;
 
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path)
+                return -ENOMEM;
 
         search_key.objectid = BTRFS_LAST_FREE_OBJECTID;
         search_key.type = -1;
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index ad9b8c0e930b..88d3cb2eaf75 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2350,12 +2350,15 @@ static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp
         struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
         struct btrfs_trans_handle *trans;
         u64 transid;
+        int ret;
 
         trans = btrfs_start_transaction(root, 0);
         if (IS_ERR(trans))
                 return PTR_ERR(trans);
         transid = trans->transid;
-        btrfs_commit_transaction_async(trans, root, 0);
+        ret = btrfs_commit_transaction_async(trans, root, 0);
+        if (ret)
+                return ret;
 
         if (argp)
                 if (copy_to_user(argp, &transid, sizeof(transid)))
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 6a1086e83ffc..29b2d7c930eb 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -88,7 +88,8 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
         search_key.offset = (u64)-1;
 
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path)
+                return -ENOMEM;
         ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
         if (ret < 0)
                 goto out;
@@ -332,7 +333,8 @@ int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
         struct extent_buffer *leaf;
 
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path)
+                return -ENOMEM;
         ret = btrfs_search_slot(trans, root, key, path, -1, 1);
         if (ret < 0)
                 goto out;
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 5b4bc685bb0e..ce48eb59d615 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -57,7 +57,8 @@ static noinline int join_transaction(struct btrfs_root *root)
         if (!cur_trans) {
                 cur_trans = kmem_cache_alloc(btrfs_transaction_cachep,
                                              GFP_NOFS);
-                BUG_ON(!cur_trans);
+                if (!cur_trans)
+                        return -ENOMEM;
                 root->fs_info->generation++;
                 cur_trans->num_writers = 1;
                 cur_trans->num_joined = 0;
@@ -195,7 +196,11 @@ again:
                 wait_current_trans(root);
 
         ret = join_transaction(root);
-        BUG_ON(ret);
+        if (ret < 0) {
+                if (type != TRANS_JOIN_NOLOCK)
+                        mutex_unlock(&root->fs_info->trans_mutex);
+                return ERR_PTR(ret);
+        }
 
         cur_trans = root->fs_info->running_transaction;
         cur_trans->use_count++;
@@ -1156,7 +1161,8 @@ int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
         struct btrfs_transaction *cur_trans;
 
         ac = kmalloc(sizeof(*ac), GFP_NOFS);
-        BUG_ON(!ac);
+        if (!ac)
+                return -ENOMEM;
 
         INIT_DELAYED_WORK(&ac->work, do_async_commit);
         ac->root = root;
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 429cfcfadf90..f9425e33e358 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -1828,7 +1828,8 @@ static int walk_log_tree(struct btrfs_trans_handle *trans,
         int orig_level;
 
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path)
+                return -ENOMEM;
 
         level = btrfs_header_level(log->node);
         orig_level = level;
@@ -3114,9 +3115,11 @@ int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
                 .stage = 0,
         };
 
-        fs_info->log_root_recovering = 1;
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path)
+                return -ENOMEM;
+
+        fs_info->log_root_recovering = 1;
 
         trans = btrfs_start_transaction(fs_info->tree_root, 0);
         BUG_ON(IS_ERR(trans));
@@ -3124,7 +3127,8 @@ int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
         wc.trans = trans;
         wc.pin = 1;
 
-        walk_log_tree(trans, log_root_tree, &wc);
+        ret = walk_log_tree(trans, log_root_tree, &wc);
+        BUG_ON(ret);
 
 again:
         key.objectid = BTRFS_TREE_LOG_OBJECTID;
@@ -3148,8 +3152,7 @@ again:
 
                 log = btrfs_read_fs_root_no_radix(log_root_tree,
                                                   &found_key);
-                BUG_ON(!log);
-
+                BUG_ON(IS_ERR(log));
 
                 tmp_key.objectid = found_key.offset;
                 tmp_key.type = BTRFS_ROOT_ITEM_KEY;