[PATCH 2/3] cdev: add diskuuid support

[Michael Olbrich]

This allows identifying disks by UUID. For disks with GPT the disk GUID is
used. For DOS partition tables the NT signature ist used, similar to how
the partuuid is generated.

Signed-off-by: Michael Olbrich <m.olbrich at pengutronix.de>
---
 common/partitions/dos.c |  3 +++
 common/partitions/efi.c |  2 ++
 fs/devfs-core.c         | 14 ++++++++++++++
 include/driver.h        |  1 +
 4 files changed, 20 insertions(+)

diff --git a/common/partitions/dos.c b/common/partitions/dos.c
index 6c76aac37172..258b10a9ed3c 100644
--- a/common/partitions/dos.c
+++ b/common/partitions/dos.c
@@ -182,6 +182,9 @@ static void dos_partition(void *buf, struct block_device *blk,
 	struct disk_signature_priv *dsp;
 	uint32_t signature = get_unaligned_le32(buf + 0x1b8);
 
+	if (signature)
+		sprintf(blk->cdev.uuid, "%08x", signature);
+
 	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 6d811bfb3b01..0787b93f120b 100644
--- a/common/partitions/efi.c
+++ b/common/partitions/efi.c
@@ -445,6 +445,8 @@ static void efi_partition(void *buf, struct block_device *blk,
 		return;
 	}
 
+	snprintf(blk->cdev.uuid, sizeof(blk->cdev.uuid), "%pUl", &gpt->disk_guid);
+
 	nb_part = le32_to_cpu(gpt->num_partition_entries);
 
 	if (nb_part > MAX_PARTITION) {
diff --git a/fs/devfs-core.c b/fs/devfs-core.c
index 82e4811b384a..2475ab959a10 100644
--- a/fs/devfs-core.c
+++ b/fs/devfs-core.c
@@ -107,6 +107,20 @@ struct cdev *cdev_by_partuuid(const char *partuuid)
 	return NULL;
 }
 
+struct cdev *cdev_by_diskuuid(const char *diskuuid)
+{
+	struct cdev *cdev;
+
+	if (!diskuuid)
+		return NULL;
+
+	list_for_each_entry(cdev, &cdev_list, list) {
+		if (!cdev->master && !strcasecmp(cdev->uuid, diskuuid))
+			return cdev;
+	}
+	return NULL;
+}
+
 /**
  * device_find_partition - find a partition belonging to a physical device
  *
diff --git a/include/driver.h b/include/driver.h
index 409ed7e02afd..e38a15f51f00 100644
--- a/include/driver.h
+++ b/include/driver.h
@@ -484,6 +484,7 @@ struct cdev *lcdev_by_name(const char *filename);
 struct cdev *cdev_readlink(struct cdev *cdev);
 struct cdev *cdev_by_device_node(struct device_node *node);
 struct cdev *cdev_by_partuuid(const char *partuuid);
+struct cdev *cdev_by_diskuuid(const char *partuuid);
 struct cdev *cdev_open(const char *name, unsigned long flags);
 struct cdev *cdev_create_loop(const char *path, ulong flags, loff_t offset);
 void cdev_remove_loop(struct cdev *cdev);
-- 
2.30.2