[PATCH v7 1/4] block: Add alternative_gpt_sector() operation

[Dmitry Osipenko <digetx@gmail.com>]

Add alternative_gpt_sector() block device operation which specifies
alternative location of a GPT entry. This allows us to support Android
devices that have GPT entry at a non-standard location and can't be
repartitioned easily.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 include/linux/blkdev.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 111a3911c4d2..d65c8f60ad8e 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1850,6 +1850,13 @@ struct block_device_operations {
 	char *(*devnode)(struct gendisk *disk, umode_t *mode);
 	struct module *owner;
 	const struct pr_ops *pr_ops;
+
+	/*
+	 * Special callback for probing GPT entry at a given sector.
+	 * Needed by Android devices, used by GPT scanner and MMC blk
+	 * driver.
+	 */
+	int (*alternative_gpt_sector)(struct gendisk *disk, sector_t *sector);
 };
 
 #ifdef CONFIG_COMPAT
-- 
2.32.0