From 7957d93bf32bc211415827e44fdd9cdf1388df59 Mon Sep 17 00:00:00 2001 From: Matteo Croce Date: Tue, 13 Jul 2021 01:05:27 +0200 Subject: [PATCH] block: add ioctl to read the disk sequence number Add a new BLKGETDISKSEQ ioctl which retrieves the disk sequence number from the genhd structure. # ./getdiskseq /dev/loop* /dev/loop0: 13 /dev/loop0p1: 13 /dev/loop0p2: 13 /dev/loop0p3: 13 /dev/loop1: 14 /dev/loop1p1: 14 /dev/loop1p2: 14 /dev/loop2: 5 /dev/loop3: 6 Reviewed-by: Christoph Hellwig Signed-off-by: Matteo Croce Tested-by: Luca Boccassi Link: https://lore.kernel.org/r/20210712230530.29323-4-mcroce@linux.microsoft.com Signed-off-by: Jens Axboe --- block/ioctl.c | 2 ++ include/uapi/linux/fs.h | 1 + 2 files changed, 3 insertions(+) diff --git a/block/ioctl.c b/block/ioctl.c index 24beec9..0c3a4a5 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -469,6 +469,8 @@ static int blkdev_common_ioctl(struct block_device *bdev, fmode_t mode, BLKDEV_DISCARD_SECURE); case BLKZEROOUT: return blk_ioctl_zeroout(bdev, mode, arg); + case BLKGETDISKSEQ: + return put_u64(argp, bdev->bd_disk->diskseq); case BLKREPORTZONE: return blkdev_report_zones_ioctl(bdev, mode, cmd, arg); case BLKRESETZONE: diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index 4c32e97..bdf7b40 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -184,6 +184,7 @@ struct fsxattr { #define BLKSECDISCARD _IO(0x12,125) #define BLKROTATIONAL _IO(0x12,126) #define BLKZEROOUT _IO(0x12,127) +#define BLKGETDISKSEQ _IOR(0x12,128,__u64) /* * A jump here: 130-136 are reserved for zoned block devices * (see uapi/linux/blkzoned.h) -- 2.7.4