Hi! I recently posted a message that addresses the usage of BUG_ON for memory shortages concerning btrfs_alloc_path() (see [1]): ... path = btrfs_alloc_path(); BUG_ON(!path); ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); ... It seems that this is not the only place where NULL pointers returned by allocation functions are not handled properly. For instance in start_transaction(), errors are not handled at all: struct btrfs_trans_handle *h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS); ... /* Access h without check */ ... return h; Repairing this would sometimes require to review a bunch of functions that directly or indirectly refer to it. As pointed out by Andi Kleen two weeks ago in a reply to message by Diego Calleja (see [2] and [3]), this might not be trivial, because these errors are sometimes not handled at all in highlevel functions. However, is there any interest in patches fixing these problems? If yes: what would be the best strategy? Should we start fixing this "layer by layer" -- the low-level functions first and the high-level functions later on? Or should use come kind of "vertical approach" -- one low-level function and all of its callers at once? If these issues currently don't have a very high priority, we could collect them in a TODO section in the Wiki or something. Any suggestions? Cheers, Andi [1] http://www.spinics.net/lists/linux-btrfs/msg03221.html [2] http://www.spinics.net/lists/linux-btrfs/msg03197.html [3] http://www.spinics.net/lists/linux-btrfs/msg03198.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
