selftests: ublk: add utility to get block device metadata size

Some block device integrity parameters are available in sysfs, but
others are only accessible using the FS_IOC_GETLBMD_CAP ioctl. Add a
metadata_size utility program to print out the logical block metadata
size, PI offset, and PI size within the metadata. Example output:
$ metadata_size /dev/ublkb0
metadata_size: 64
pi_offset: 56
pi_tuple_size: 8

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/tools/testing/selftests/ublk/Makefile b/tools/testing/selftests/ublk/Makefile
index 06ba6fde098de9ce8ee742e14de817c6a7a1c441..351ac64385613d8977b78774e2326e96a769e0fe 100644 (file)
--- a/tools/testing/selftests/ublk/Makefile
+++ b/tools/testing/selftests/ublk/Makefile
@@ -49,12 +49,13 @@ TEST_PROGS += test_stress_05.sh
 TEST_PROGS += test_stress_06.sh
 TEST_PROGS += test_stress_07.sh
 
-TEST_GEN_PROGS_EXTENDED = kublk
+TEST_GEN_PROGS_EXTENDED = kublk metadata_size
+STANDALONE_UTILS := metadata_size.c
 
 LOCAL_HDRS += $(wildcard *.h)
 include ../lib.mk
 
-$(TEST_GEN_PROGS_EXTENDED): $(wildcard *.c)
+$(OUTPUT)/kublk: $(filter-out $(STANDALONE_UTILS),$(wildcard *.c))
 
 check:
        shellcheck -x -f gcc *.sh

diff --git a/tools/testing/selftests/ublk/metadata_size.c b/tools/testing/selftests/ublk/metadata_size.c
new file mode 100644 (file)
index 0000000..76ecddf
--- /dev/null
+++ b/tools/testing/selftests/ublk/metadata_size.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <fcntl.h>
+#include <linux/fs.h>
+#include <stdio.h>
+#include <sys/ioctl.h>
+
+int main(int argc, char **argv)
+{
+       struct logical_block_metadata_cap cap = {};
+       const char *filename;
+       int fd;
+       int result;
+
+       if (argc != 2) {
+               fprintf(stderr, "Usage: %s BLOCK_DEVICE\n", argv[0]);
+               return 1;
+       }
+
+       filename = argv[1];
+       fd = open(filename, O_RDONLY);
+       if (fd < 0) {
+               perror(filename);
+               return 1;
+       }
+
+       result = ioctl(fd, FS_IOC_GETLBMD_CAP, &cap);
+       if (result < 0) {
+               perror("ioctl");
+               return 1;
+       }
+
+       printf("metadata_size: %u\n", cap.lbmd_size);
+       printf("pi_offset: %u\n", cap.lbmd_pi_offset);
+       printf("pi_tuple_size: %u\n", cap.lbmd_pi_size);
+       return 0;
+}