blockdev: add support for ioctl BLKGETDISKSEQ

disk-utils/blockdev.8.adoc

@@ -57,6 +57,9 @@ Print the blocksize in bytes. This size does not describe device topology. It's
 *--getdiscardzeroes*::
 Get discard zeroes support status.
 
+*--getdiskseq*::
+Get disk sequence number.
+
 *--getfra*::
 Get filesystem readahead in 512-byte sectors.
 

disk-utils/blockdev.c

@@ -168,6 +168,12 @@ static const struct bdc bdcms[] =
 		.argtype = ARG_LONG,
 		.argval = -1,
 		.help = N_("get filesystem readahead")
+	},{
+		IOCTL_ENTRY(BLKGETDISKSEQ),
+		.name = "--getdiskseq",
+		.argtype = ARG_ULLONG,
+		.argval = -1,
+		.help = N_("get disk sequence number")
 	},{
 		IOCTL_ENTRY(BLKFLSBUF),
 		.name = "--flushbufs",

include/blkdev.h

@@ -64,6 +64,11 @@
 #  define BLKDISCARDZEROES _IO(0x12,124)
 # endif
 
+/* disk sequence number, introduced in 5.15 (commit 7957d93b) */
+# ifndef BLKGETDISKSEQ
+#  define BLKGETDISKSEQ _IOR(0x12, 128, uint64_t)
+# endif
+
 /* filesystem freeze, introduced in 2.6.29 (commit fcccf502) */
 # ifndef FIFREEZE
 #  define FIFREEZE   _IOWR('X', 119, int)    /* Freeze */