On 05/04/12 20:54, Alexander Block wrote:
The comment above ulist_next stated that it's allowed to call ulist_add
while enumerating. This is actually not allowed as an add may realocate
the nodes buffer und thus make the prev pointer invalid.
Signed-off-by: Alexander Block<ablock84@xxxxxxxxxxxxxx>
I'd much prefer to fix the problem in ulist_next, as being able to add
values while enumerating is a key feature of ulist. If it's unfixable,
it should be thrown out completely.
-Arne
---
fs/btrfs/ulist.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/ulist.c b/fs/btrfs/ulist.c
index 12f5147..07ea3e5 100644
--- a/fs/btrfs/ulist.c
+++ b/fs/btrfs/ulist.c
@@ -198,8 +198,8 @@ EXPORT_SYMBOL(ulist_add);
* end is reached. No guarantee is made with respect to the order in which
* the elements are returned. They might neither be returned in order of
* addition nor in ascending order.
- * It is allowed to call ulist_add during an enumeration. Newly added items
- * are guaranteed to show up in the running enumeration.
+ * It is not allowed to call ulist_add during an enumeration as this would
+ * cause undefined behavior.
*/
struct ulist_node *ulist_next(struct ulist *ulist, struct ulist_node *prev)
{
--
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