mtd: partitions: support a cleanup callback for parsers
If partition parsers need to clean up their resources, we shouldn't
assume that all memory will fit in a single kmalloc() that the caller
can kfree(). We should allow the parser to provide a proper cleanup
routine.
Note that this means we need to keep a hold on the parser's module for a
bit longer, and release it later with mtd_part_parser_put().
Alongside this, define a default callback that we'll automatically use
if the parser doesn't provide one, so we can still retain the old
behavior.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 53517d7..10bf304 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -709,10 +709,23 @@
module_put(p->owner);
}
+/*
+ * Many partition parsers just expected the core to kfree() all their data in
+ * one chunk. Do that by default.
+ */
+static void mtd_part_parser_cleanup_default(const struct mtd_partition *pparts,
+ int nr_parts)
+{
+ kfree(pparts);
+}
+
int __register_mtd_parser(struct mtd_part_parser *p, struct module *owner)
{
p->owner = owner;
+ if (!p->cleanup)
+ p->cleanup = &mtd_part_parser_cleanup_default;
+
spin_lock(&part_parser_lock);
list_add(&p->list, &part_parsers);
spin_unlock(&part_parser_lock);
@@ -756,7 +769,9 @@
* This function may return:
* o a negative error code in case of failure
* o zero otherwise, and @pparts will describe the partitions, number of
- * partitions, and the parser which parsed them
+ * partitions, and the parser which parsed them. Caller must release
+ * resources with mtd_part_parser_cleanup() when finished with the returned
+ * data.
*/
int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
struct mtd_partitions *pparts,
@@ -780,7 +795,6 @@
ret = (*parser->parse_fn)(master, &pparts->parts, data);
pr_debug("%s: parser %s: %i\n",
master->name, parser->name, ret);
- mtd_part_parser_put(parser);
if (ret > 0) {
printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
ret, parser->name, master->name);
@@ -788,6 +802,7 @@
pparts->parser = parser;
return 0;
}
+ mtd_part_parser_put(parser);
/*
* Stash the first error we see; only report it if no parser
* succeeds
@@ -798,6 +813,22 @@
return err;
}
+void mtd_part_parser_cleanup(struct mtd_partitions *parts)
+{
+ const struct mtd_part_parser *parser;
+
+ if (!parts)
+ return;
+
+ parser = parts->parser;
+ if (parser) {
+ if (parser->cleanup)
+ parser->cleanup(parts->parts, parts->nr_parts);
+
+ mtd_part_parser_put(parser);
+ }
+}
+
int mtd_is_partition(const struct mtd_info *mtd)
{
struct mtd_part *part;