[patch] error handling of ERR_PTR() returns

Dan Carpenter
2009-04-07T13:38:42Z

There are a couple functions which return ERR_PTR as well as NULL. The
caller needs to handle both.

Smatch also complains about the handling of alloc_extent_map() but as far
as I can see that doesn't actually return an ERR_PTR.

Compile tested on 2.6.29.

regards,
dan carpenter

--- orig/fs/btrfs/disk-io.c 2009-04-07 16:15:36.000000000 +0300
+++ devel/fs/btrfs/disk-io.c 2009-04-07 16:23:33.000000000 +0300
@@ -123,7 +123,7 @@

spin_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, len);
- if (em) {
+ if (!IS_ERR(em) && em) {
em->bdev =
BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
spin_unlock(&em_tree->lock);
@@ -1216,8 +1216,8 @@
int ret;

root = btrfs_read_fs_root_no_name(fs_info, location);
- if (!root)
- return NULL;
+ if (!root || IS_ERR(root))
+ return root;

if (root->in_sysfs)
return root;
@@ -1324,7 +1324,7 @@
spin_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
spin_unlock(&em_tree->lock);
- if (!em) {
+ if (!em || IS_ERR(em)) {
__unplug_io_fn(bdi, page);
return;
}