[PATCH 1/2] disk: part: Add API to get partitions with specific driver

[Joshua Watt]

Adds part_driver_get_type() API which can be used to force a specific
driver to be used when getting partition information instead of relying
on auto detection.

Signed-off-by: Joshua Watt <jpewhac...@gmail.com>
---
 disk/part.c    | 38 +++++++++++++++++++++++++++++++-------
 include/part.h |  2 ++
 2 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/disk/part.c b/disk/part.c
index 35300df590..1f8c786ca5 100644
--- a/disk/part.c
+++ b/disk/part.c
@@ -26,6 +26,22 @@
 /* Check all partition types */
 #define PART_TYPE_ALL          -1
 
+static struct part_driver *part_driver_get_type(int part_type)
+{
+       struct part_driver *drv =
+               ll_entry_start(struct part_driver, part_driver);
+       const int n_ents = ll_entry_count(struct part_driver, part_driver);
+       struct part_driver *entry;
+
+       for (entry = drv; entry != drv + n_ents; entry++) {
+               if (part_type == entry->part_type)
+                       return entry;
+       }
+
+       /* Not found */
+       return NULL;
+}
+
 static struct part_driver *part_driver_lookup_type(struct blk_desc *dev_desc)
 {
        struct part_driver *drv =
@@ -44,10 +60,7 @@ static struct part_driver *part_driver_lookup_type(struct 
blk_desc *dev_desc)
                        }
                }
        } else {
-               for (entry = drv; entry != drv + n_ents; entry++) {
-                       if (dev_desc->part_type == entry->part_type)
-                               return entry;
-               }
+               return part_driver_get_type(dev_desc->part_type);
        }
 
        /* Not found */
@@ -306,8 +319,8 @@ void part_print(struct blk_desc *dev_desc)
                drv->print(dev_desc);
 }
 
-int part_get_info(struct blk_desc *dev_desc, int part,
-                      struct disk_partition *info)
+int part_get_info_by_type(struct blk_desc *dev_desc, int part, int part_type,
+                         struct disk_partition *info)
 {
        struct part_driver *drv;
 
@@ -320,7 +333,12 @@ int part_get_info(struct blk_desc *dev_desc, int part,
                info->type_guid[0] = 0;
 #endif
 
-               drv = part_driver_lookup_type(dev_desc);
+               if (part_type == PART_TYPE_UNKNOWN) {
+                       drv = part_driver_lookup_type(dev_desc);
+               } else {
+                       drv = part_driver_get_type(part_type);
+               }
+
                if (!drv) {
                        debug("## Unknown partition table type %x\n",
                              dev_desc->part_type);
@@ -340,6 +358,12 @@ int part_get_info(struct blk_desc *dev_desc, int part,
        return -ENOENT;
 }
 
+int part_get_info(struct blk_desc *dev_desc, int part,
+                 struct disk_partition *info)
+{
+       return part_get_info_by_type(dev_desc, part, PART_TYPE_UNKNOWN, info);
+}
+
 int part_get_info_whole_disk(struct blk_desc *dev_desc,
                             struct disk_partition *info)
 {
diff --git a/include/part.h b/include/part.h
index be75c73549..f150c84206 100644
--- a/include/part.h
+++ b/include/part.h
@@ -106,6 +106,8 @@ struct blk_desc *blk_get_dev(const char *ifname, int dev);
 struct blk_desc *mg_disk_get_dev(int dev);
 
 /* disk/part.c */
+int part_get_info_by_type(struct blk_desc *dev_desc, int part, int part_type,
+                         struct disk_partition *info);
 int part_get_info(struct blk_desc *dev_desc, int part,
                  struct disk_partition *info);
 /**
-- 
2.33.0