From b251424242b46d62f666829c0e7a7550768fc8de Mon Sep 17 00:00:00 2001

From: Pawel Baldysiak <pawel.baldysiak@intel.com>

Date: Thu, 28 Sep 2017 14:41:11 +0200

Subject: [PATCH 05/12] Zeroout whole ppl space during creation/force

 assemble

PPL area should be cleared before creation/force assemble.

If the drive was used in other RAID array, it might contains PPL from it.

There is a risk that mdadm recognizes those PPLs and

refuses to assemble the RAID due to PPL conflict with created

array.

Signed-off-by: Pawel Baldysiak <pawel.baldysiak@intel.com>

Signed-off-by: Jes Sorensen <jsorensen@fb.com>

---

 mdadm.h       |  1 +

 super-intel.c |  7 ++++++-

 super1.c      |  5 +++++

 util.c        | 49 +++++++++++++++++++++++++++++++++++++++++++++++++

 4 files changed, 61 insertions(+), 1 deletion(-)

diff --git a/mdadm.h b/mdadm.h

index 3fc8a4f..85947bf 100644

--- a/mdadm.h

+++ b/mdadm.h

@@ -687,6 +687,7 @@ extern int sysfs_unique_holder(char *devnm, long rdev);

 extern int sysfs_freeze_array(struct mdinfo *sra);

 extern int sysfs_wait(int fd, int *msec);

 extern int load_sys(char *path, char *buf, int len);

+extern int zero_disk_range(int fd, unsigned long long sector, size_t count);

 extern int reshape_prepare_fdlist(char *devname,

 				  struct mdinfo *sra,

 				  int raid_disks,

diff --git a/super-intel.c b/super-intel.c

index 56dec36..65cdc92 100644

--- a/super-intel.c

+++ b/super-intel.c

@@ -6065,7 +6065,12 @@ static int write_init_ppl_imsm(struct supertype *st, struct mdinfo *info, int fd

 	struct ppl_header *ppl_hdr;

 	int ret;

-	ret = posix_memalign(&buf, 4096, PPL_HEADER_SIZE);

+	/* first clear entire ppl space */

+	ret = zero_disk_range(fd, info->ppl_sector, info->ppl_size);

+	if (ret)

+		return ret;

+

+	ret = posix_memalign(&buf, MAX_SECTOR_SIZE, PPL_HEADER_SIZE);

 	if (ret) {

 		pr_err("Failed to allocate PPL header buffer\n");

 		return ret;

diff --git a/super1.c b/super1.c

index f80e38a..7ae6dc3 100644

--- a/super1.c

+++ b/super1.c

@@ -1823,6 +1823,11 @@ static int write_init_ppl1(struct supertype *st, struct mdinfo *info, int fd)

 	struct ppl_header *ppl_hdr;

 	int ret;

+	/* first clear entire ppl space */

+	ret = zero_disk_range(fd, info->ppl_sector, info->ppl_size);

+	if (ret)

+		return ret;

+

 	ret = posix_memalign(&buf, 4096, PPL_HEADER_SIZE);

 	if (ret) {

 		pr_err("Failed to allocate PPL header buffer\n");

diff --git a/util.c b/util.c

index 68af381..c11729e 100644

--- a/util.c

+++ b/util.c

@@ -30,6 +30,7 @@

 #include	<sys/un.h>

 #include	<sys/resource.h>

 #include	<sys/vfs.h>

+#include	<sys/mman.h>

 #include	<linux/magic.h>

 #include	<poll.h>

 #include	<ctype.h>

@@ -2334,3 +2335,51 @@ void set_hooks(void)

 	set_dlm_hooks();

 	set_cmap_hooks();

 }

+

+int zero_disk_range(int fd, unsigned long long sector, size_t count)

+{

+	int ret = 0;

+	int fd_zero;

+	void *addr = NULL;

+	size_t written = 0;

+	size_t len = count * 512;

+	ssize_t n;

+

+	fd_zero = open("/dev/zero", O_RDONLY);

+	if (fd_zero < 0) {

+		pr_err("Cannot open /dev/zero\n");

+		return -1;

+	}

+

+	if (lseek64(fd, sector * 512, SEEK_SET) < 0) {

+		ret = -errno;

+		pr_err("Failed to seek offset for zeroing\n");

+		goto out;

+	}

+

+	addr = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd_zero, 0);

+

+	if (addr == MAP_FAILED) {

+		ret = -errno;

+		pr_err("Mapping /dev/zero failed\n");

+		goto out;

+	}

+

+	do {

+		n = write(fd, addr + written, len - written);

+		if (n < 0) {

+			if (errno == EINTR)

+				continue;

+			ret = -errno;

+			pr_err("Zeroing disk range failed\n");

+			break;

+		}

+		written += n;

+	} while (written != len);

+

+	munmap(addr, len);

+

+out:

+	close(fd_zero);

+	return ret;

+}

-- 

2.7.4