[PATCH v2 13/19] common: partitions: record whether disk is GPT or MBR partitioned

[Ahmad Fatoum]

Currently, the only way to differentiate between a GPT disk and a MBR
one is to check whether the cdev's device has a guid (=> GPT) or a
nt_signature (=> MBR) device parameter. We already have a flag parameter
though, so let's record this info there for easy retrieval.

We intentionally don't use the struct cdev::filetype member, because
we don't want to change behavior of file_detect_type().

Reviewed-by: Marco Felsch <m.felsch at pengutronix.de>
Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
v1 -> v2:
  - remove unneeded == DEVFS_IS comparison, because constants are
    single-bit (Marco)
  - Add Marco's Reviewed-by
  - Reorder bits, to reduce diff size
---
 common/partitions/dos.c |  2 ++
 common/partitions/efi.c |  2 ++
 fs/fs.c                 |  4 ++++
 include/driver.h        | 12 ++++++++++++
 4 files changed, 20 insertions(+)

diff --git a/common/partitions/dos.c b/common/partitions/dos.c
index ad60c0b27b46..7472824b00b9 100644
--- a/common/partitions/dos.c
+++ b/common/partitions/dos.c
@@ -185,6 +185,8 @@ static void dos_partition(void *buf, struct block_device *blk,
 	if (signature)
 		sprintf(blk->cdev.diskuuid, "%08x", signature);
 
+	blk->cdev.flags |= DEVFS_IS_MBR_PARTITIONED;
+
 	table = (struct partition_entry *)&buffer[446];
 
 	for (i = 0; i < 4; i++) {
diff --git a/common/partitions/efi.c b/common/partitions/efi.c
index 258e7210d2af..c5cd941a91e7 100644
--- a/common/partitions/efi.c
+++ b/common/partitions/efi.c
@@ -449,6 +449,8 @@ static void efi_partition(void *buf, struct block_device *blk,
 	snprintf(blk->cdev.diskuuid, sizeof(blk->cdev.diskuuid), "%pUl", &gpt->disk_guid);
 	dev_add_param_string_fixed(blk->dev, "guid", blk->cdev.diskuuid);
 
+	blk->cdev.flags |= DEVFS_IS_GPT_PARTITIONED;
+
 	nb_part = le32_to_cpu(gpt->num_partition_entries);
 
 	if (nb_part > MAX_PARTITION) {
diff --git a/fs/fs.c b/fs/fs.c
index 952ed73dbca5..cac4bec49027 100644
--- a/fs/fs.c
+++ b/fs/fs.c
@@ -94,6 +94,10 @@ void cdev_print(const struct cdev *cdev)
 			printf(" table-partition");
 		if (cdev->flags & DEVFS_IS_MCI_MAIN_PART_DEV)
 			printf(" mci-main-partition");
+		if (cdev->flags & DEVFS_IS_MBR_PARTITIONED)
+			printf(" mbr-partitioned");
+		if (cdev->flags & DEVFS_IS_GPT_PARTITIONED)
+			printf(" gpt-partitioned");
 		if (cdev->mtd)
 			printf(" mtd");
 		printf(" )");
diff --git a/include/driver.h b/include/driver.h
index 2cd8a6489ee6..84cf324c7de4 100644
--- a/include/driver.h
+++ b/include/driver.h
@@ -587,6 +587,18 @@ extern struct list_head cdev_list;
 #define DEVFS_IS_MCI_MAIN_PART_DEV	(1U << 4)
 #define DEVFS_PARTITION_FROM_OF		(1U << 5)
 #define DEVFS_PARTITION_FROM_TABLE	(1U << 6)
+#define DEVFS_IS_MBR_PARTITIONED	(1U << 7)
+#define DEVFS_IS_GPT_PARTITIONED	(1U << 8)
+
+static inline bool cdev_is_mbr_partitioned(const struct cdev *master)
+{
+	return master && (master->flags & DEVFS_IS_MBR_PARTITIONED);
+}
+
+static inline bool cdev_is_gpt_partitioned(const struct cdev *master)
+{
+	return master && (master->flags & DEVFS_IS_GPT_PARTITIONED);
+}
 
 struct cdev *devfs_add_partition(const char *devname, loff_t offset,
 		loff_t size, unsigned int flags, const char *name);
-- 
2.39.2