mtd: partitions: pass around 'mtd_partitions' wrapper struct

For some of the core partitioning code, it helps to keep info about the
parsed partition (and who parsed them) together in one place.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 868ee52..20b2b38 100644 (file)
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -532,9 +532,10 @@ out_error:
 }
 
 static int mtd_add_device_partitions(struct mtd_info *mtd,
-                                    const struct mtd_partition *real_parts,
-                                    int nbparts)
+                                    struct mtd_partitions *parts)
 {
+       const struct mtd_partition *real_parts = parts->parts;
+       int nbparts = parts->nr_parts;
        int ret;
 
        if (nbparts == 0 || IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
@@ -588,23 +589,27 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
                              const struct mtd_partition *parts,
                              int nr_parts)
 {
+       struct mtd_partitions parsed;
        int ret;
-       const struct mtd_partition *real_parts = NULL;
 
-       ret = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
-       if (ret <= 0 && nr_parts && parts) {
-               real_parts = parts;
-               ret = nr_parts;
-       }
-       /* Didn't come up with either parsed OR fallback partitions */
-       if (ret < 0) {
+       memset(&parsed, 0, sizeof(parsed));
+
+       ret = parse_mtd_partitions(mtd, types, &parsed, parser_data);
+       if ((ret < 0 || parsed.nr_parts == 0) && parts && nr_parts) {
+               /* Fall back to driver-provided partitions */
+               parsed = (struct mtd_partitions){
+                       .parts          = parts,
+                       .nr_parts       = nr_parts,
+               };
+       } else if (ret < 0) {
+               /* Didn't come up with parsed OR fallback partitions */
                pr_info("mtd: failed to find partitions; one or more parsers reports errors (%d)\n",
                        ret);
                /* Don't abort on errors; we can still use unpartitioned MTD */
-               ret = 0;
+               memset(&parsed, 0, sizeof(parsed));
        }
 
-       ret = mtd_add_device_partitions(mtd, real_parts, ret);
+       ret = mtd_add_device_partitions(mtd, &parsed);
        if (ret)
                goto out;
 
@@ -625,8 +630,8 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
 
 out:
        /* Cleanup any parsed partitions */
-       if (real_parts != parts)
-               kfree(real_parts);
+       if (parsed.parser)
+               kfree(parsed.parts);
        return ret;
 }
 EXPORT_SYMBOL_GPL(mtd_device_parse_register);

diff --git a/drivers/mtd/mtdcore.h b/drivers/mtd/mtdcore.h
index 537ec66..ce81cc2 100644 (file)
--- a/drivers/mtd/mtdcore.h
+++ b/drivers/mtd/mtdcore.h
@@ -10,8 +10,11 @@ int add_mtd_device(struct mtd_info *mtd);
 int del_mtd_device(struct mtd_info *mtd);
 int add_mtd_partitions(struct mtd_info *, const struct mtd_partition *, int);
 int del_mtd_partitions(struct mtd_info *);
+
+struct mtd_partitions;
+
 int parse_mtd_partitions(struct mtd_info *master, const char * const *types,
-                        const struct mtd_partition **pparts,
+                        struct mtd_partitions *pparts,
                         struct mtd_part_parser_data *data);
 
 int __init init_mtdchar(void);

diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 898999c..53517d7 100644 (file)
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -743,7 +743,7 @@ static const char * const default_mtd_part_types[] = {
  * parse_mtd_partitions - parse MTD partitions
  * @master: the master partition (describes whole MTD device)
  * @types: names of partition parsers to try or %NULL
- * @pparts: array of partitions found is returned here
+ * @pparts: info about partitions found is returned here
  * @data: MTD partition parser-specific data
  *
  * This function tries to find partition on MTD device @master. It uses MTD
@@ -755,12 +755,11 @@ static const char * const default_mtd_part_types[] = {
  *
  * This function may return:
  * o a negative error code in case of failure
- * o zero if no partitions were found
- * o a positive number of found partitions, in which case on exit @pparts will
- *   point to an array containing this number of &struct mtd_info objects.
+ * o zero otherwise, and @pparts will describe the partitions, number of
+ *   partitions, and the parser which parsed them
  */
 int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
-                        const struct mtd_partition **pparts,
+                        struct mtd_partitions *pparts,
                         struct mtd_part_parser_data *data)
 {
        struct mtd_part_parser *parser;
@@ -778,14 +777,16 @@ int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
                         parser ? parser->name : NULL);
                if (!parser)
                        continue;
-               ret = (*parser->parse_fn)(master, pparts, data);
+               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);
-                       return ret;
+                       pparts->nr_parts = ret;
+                       pparts->parser = parser;
+                       return 0;
                }
                /*
                 * Stash the first error we see; only report it if no parser

diff --git a/include/linux/mtd/partitions.h b/include/linux/mtd/partitions.h
index 6185536..cceaf7b 100644 (file)
--- a/include/linux/mtd/partitions.h
+++ b/include/linux/mtd/partitions.h
@@ -73,6 +73,13 @@ struct mtd_part_parser {
                        struct mtd_part_parser_data *);
 };
 
+/* Container for passing around a set of parsed partitions */
+struct mtd_partitions {
+       const struct mtd_partition *parts;
+       int nr_parts;
+       const struct mtd_part_parser *parser;
+};
+
 extern int __register_mtd_parser(struct mtd_part_parser *parser,
                                 struct module *owner);
 #define register_mtd_parser(parser) __register_mtd_parser(parser, THIS_MODULE)