[PATCH 1/7] block: add a ->get_unique_id method
From: Christoph Hellwig <hch@lst.de>
Date: 2021-10-21 06:06:19
Also in:
linux-nfs, linux-scsi, target-devel
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
Add a method to query unique IDs from block devices. It will be used to remove code that deeply pokes into SCSI internals in the NFS server. The implementation in the sd driver itself is also much nicer as it can use the cached VPD page instead of always sending a command as the current NFS code does. For now the interface is kept very minimal but could be easily extended when other users like a block-layer sysfs interface for uniquue IDs shows up. Signed-off-by: Christoph Hellwig <hch@lst.de> --- include/linux/blkdev.h | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index fd9771a1da096..af61fb3e1502c 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h@@ -1177,6 +1177,14 @@ static inline void blk_ksm_unregister(struct request_queue *q) { } #endif /* CONFIG_BLK_INLINE_ENCRYPTION */ +enum blk_unique_id { + /* these match the Designator Types specified in SPC */ + BLK_UID_T10 = 1, + BLK_UID_EUI64 = 2, + BLK_UID_NAA = 3, +}; + +#define NFL4_UFLG_MASK 0x0000003F struct block_device_operations { void (*submit_bio)(struct bio *bio);
@@ -1195,6 +1203,9 @@ struct block_device_operations { int (*report_zones)(struct gendisk *, sector_t sector, unsigned int nr_zones, report_zones_cb cb, void *data); char *(*devnode)(struct gendisk *disk, umode_t *mode); + /* returns the length of the identifier or a negative errno: */ + int (*get_unique_id)(struct gendisk *disk, u8 id[16], + enum blk_unique_id id_type); struct module *owner; const struct pr_ops *pr_ops;
--
2.30.2