From: Christoph Hellwig Date: Thu, 21 Oct 2021 06:06:01 +0000 (+0200) Subject: block: add a ->get_unique_id method X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9208d414975895f69e9aca49153060ddd31b18d0;p=linux.git block: add a ->get_unique_id method 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 Reviewed-by: Hannes Reinecke Link: https://lore.kernel.org/r/20211021060607.264371-2-hch@lst.de Signed-off-by: Jens Axboe --- diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index f72ccb2829db9..0d5826066e16b 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1158,6 +1158,14 @@ static inline void blk_crypto_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); @@ -1176,6 +1184,9 @@ 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;