btrfs: replace many BUG_ONs with proper error handling
btrfs currently handles most errors with BUG_ON. This patch is a work-in-
progress but aims to handle most errors other than internal logic
errors and ENOMEM more gracefully.
This iteration prevents most crashes but can run into lockups with
the page lock on occasion when the timing "works out."
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index cba7a0b..017281d 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -4102,10 +4102,11 @@
static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
{
struct btrfs_trans_handle *trans;
- int ret;
+ int ret, err;
trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
- BUG_ON(IS_ERR(trans));
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
memset(&root->root_item.drop_progress, 0,
sizeof(root->root_item.drop_progress));
@@ -4113,11 +4114,11 @@
btrfs_set_root_refs(&root->root_item, 0);
ret = btrfs_update_root(trans, root->fs_info->tree_root,
&root->root_key, &root->root_item);
- BUG_ON(ret);
- ret = btrfs_end_transaction(trans, root->fs_info->tree_root);
- BUG_ON(ret);
- return 0;
+ err = btrfs_end_transaction(trans, root->fs_info->tree_root);
+ if (err)
+ return err;
+ return ret;
}
/*
@@ -4185,7 +4186,11 @@
err = ret;
goto out;
}
- mark_garbage_root(reloc_root);
+ ret = mark_garbage_root(reloc_root);
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ }
}
}
@@ -4231,14 +4236,19 @@
fs_root = read_fs_root(root->fs_info,
reloc_root->root_key.offset);
- BUG_ON(IS_ERR(fs_root));
+ if (IS_ERR(fs_root)) {
+ err = PTR_ERR(fs_root);
+ goto out_free;
+ }
err = __add_reloc_root(reloc_root);
- BUG_ON(err < 0);
+ BUG_ON(err < 0); /* -ENOMEM or logic error */
fs_root->reloc_root = reloc_root;
}
- btrfs_commit_transaction(trans, rc->extent_root);
+ err = btrfs_commit_transaction(trans, rc->extent_root);
+ if (err)
+ goto out_free;
merge_reloc_roots(rc);
@@ -4248,7 +4258,7 @@
if (IS_ERR(trans))
err = PTR_ERR(trans);
else
- btrfs_commit_transaction(trans, rc->extent_root);
+ err = btrfs_commit_transaction(trans, rc->extent_root);
out_free:
kfree(rc);
out:
@@ -4297,6 +4307,8 @@
disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
disk_bytenr + len - 1, &list, 0);
+ if (ret)
+ goto out;
while (!list_empty(&list)) {
sums = list_entry(list.next, struct btrfs_ordered_sum, list);
@@ -4314,6 +4326,7 @@
btrfs_add_ordered_sum(inode, ordered, sums);
}
+out:
btrfs_put_ordered_extent(ordered);
return ret;
}