MISC: Add --examine-badblocks option

This will list the contents of the bad-blocks log, if one is present.

Signed-off-by: NeilBrown <neilb@suse.de>

Examine.c

@@ -187,3 +187,39 @@ int Examine(struct mddev_dev *devlist,
 	}
 	return rv;
 }
+
+int ExamineBadblocks(char *devname, int brief, struct supertype *forcest)
+{
+	int fd = dev_open(devname, O_RDONLY);
+	struct supertype *st = forcest;
+	int err = 1;
+
+	if (fd < 0) {
+		pr_err("cannot open %s: %s\n", devname, strerror(errno));
+		return 1;
+	}
+	if (!st)
+		st = guess_super(fd);
+	if (!st) {
+		if (!brief)
+			pr_err("No md superblock detected on %s\n", devname);
+		goto out;
+	}
+	if (!st->ss->examine_badblocks) {
+		pr_err("%s metadata does not support badblocks\n", st->ss->name);
+		goto out;
+	}
+	err = st->ss->load_super(st, fd, brief ? NULL : devname);
+	if (err)
+		goto out;
+	err = st->ss->examine_badblocks(st, fd, devname);
+
+out:
+	if (fd >= 0)
+		close(fd);
+	if (st) {
+		st->ss->free_super(st);
+		free(st);
+	}
+	return err;
+}

ReadMe.c

@@ -95,6 +95,7 @@ struct option long_options[] = {
     {"update-subarray", 1, 0, UpdateSubarray},
     {"udev-rules", 2, 0, UdevRules},
     {"offroot", 0, 0, OffRootOpt},
+    {"examine-badblocks", 0, 0, ExamineBB},
 
     /* synonyms */
     {"monitor",   0, 0, 'F'},
@@ -251,6 +252,7 @@ char OptionHelp[] =
 "  --detail      -D   : Display details of an array\n"
 "  --examine     -E   : Examine superblock on an array component\n"
 "  --examine-bitmap -X: Display the detail of a bitmap file\n"
+"  --examine-badblocks: Display list of known bad blocks on device\n"
 "  --monitor     -F   : monitor (follow) some arrays\n"
 "  --grow        -G   : resize/ reshape and array\n"
 "  --incremental -I   : add/remove a single device to/from an array as appropriate\n"
@@ -490,6 +492,7 @@ char Help_misc[] =
 "  --detail-platform  : Display hardware/firmware details\n"
 "  --examine     -E   : Examine superblock on an array component\n"
 "  --examine-bitmap -X: Display contents of a bitmap file\n"
+"  --examine-badblocks: Display list of known bad blocks on device\n"
 "  --zero-superblock  : erase the MD superblock from a device.\n"
 "  --run         -R   : start a partially built array\n"
 "  --stop        -S   : deactivate array, releasing all resources\n"

mdadm.8.in

@@ -1426,6 +1426,13 @@ device (e.g.
 .BR /dev/md0 )
 does not report the bitmap for that array.
 
+.TP
+.B \-\-examine\-badblocks
+List the bad-blocks recorded for the device, if a bad-blocks list has
+been configured.  Currently only
+.B 1.x
+metadata supports bad-blocks lists.
+
 .TP
 .BR \-R ", " \-\-run
 start a partially assembled array.  If

mdadm.c

@@ -232,6 +232,7 @@ int main(int argc, char *argv[])
 		case 'E':
 		case 'X':
 		case 'Q':
+		case ExamineBB:
 			newmode = MISC;
 			break;
 
@@ -971,6 +972,7 @@ int main(int argc, char *argv[])
 		case O(MISC,'R'):
 		case O(MISC,'S'):
 		case O(MISC,'X'):
+		case O(MISC, ExamineBB):
 		case O(MISC,'o'):
 		case O(MISC,'w'):
 		case O(MISC,'W'):
@@ -1750,6 +1752,8 @@ static int misc_list(struct mddev_dev *devlist,
 			rv |= Query(dv->devname); continue;
 		case 'X':
 			rv |= ExamineBitmap(dv->devname, c->brief, ss); continue;
+		case ExamineBB:
+			rv |= ExamineBadblocks(dv->devname, c->brief, ss); continue;
 		case 'W':
 		case WaitOpt:
 			rv |= Wait(dv->devname); continue;

mdadm.h

@@ -337,6 +337,7 @@ enum special_options {
 	Prefer,
 	KillOpt,
 	DataOffset,
+	ExamineBB,
 };
 
 enum prefix_standard {
@@ -662,6 +663,7 @@ extern struct superswitch {
 	void (*brief_examine_super)(struct supertype *st, int verbose);
 	void (*brief_examine_subarrays)(struct supertype *st, int verbose);
 	void (*export_examine_super)(struct supertype *st);
+	int (*examine_badblocks)(struct supertype *st, int fd, char *devname);
 
 	/* Used to report details of an active array.
 	 * ->load_super was possibly given a 'component' string.
@@ -1145,6 +1147,7 @@ extern int Create(struct supertype *st, char *mddev,
 extern int Detail(char *dev, struct context *c);
 extern int Detail_Platform(struct superswitch *ss, int scan, int verbose, int export, char *controller_path);
 extern int Query(char *dev);
+extern int ExamineBadblocks(char *devname, int brief, struct supertype *forcest);
 extern int Examine(struct mddev_dev *devlist, struct context *c,
 		   struct supertype *forcest);
 extern int Monitor(struct mddev_dev *devlist,

super1.c

@@ -648,6 +648,59 @@ static void export_detail_super1(struct supertype *st)
 		printf("MD_NAME=%.*s\n", len, sb->set_name);
 }
 
+static int examine_badblocks_super1(struct supertype *st, int fd, char *devname)
+{
+	struct mdp_superblock_1 *sb = st->sb;
+	unsigned long long offset;
+	int size;
+	__u64 *bbl, *bbp;
+	int i;
+
+	if  (!sb->bblog_size || __le32_to_cpu(sb->bblog_size) > 100
+	     || !sb->bblog_offset){
+		printf("No bad-blocks list configured on %s\n", devname);
+		return 0;
+	}
+	if ((sb->feature_map & __cpu_to_le32(MD_FEATURE_BAD_BLOCKS))
+	    == 0) {
+		printf("Bad-blocks list is empty in %s\n", devname);
+		return 0;
+	}
+
+	size = __le32_to_cpu(sb->bblog_size)* 512;
+	posix_memalign((void**)&bbl, 4096, size);
+	offset = __le64_to_cpu(sb->super_offset) +
+		(int)__le32_to_cpu(sb->bblog_offset);
+	offset <<= 9;
+	if (lseek64(fd, offset, 0) < 0) {
+		pr_err("Cannot seek to bad-blocks list\n");
+		return 1;
+	}
+	if (read(fd, bbl, size) != size) {
+		pr_err("Cannot read bad-blocks list\n");
+		return 1;
+	}
+	/* 64bits per entry. 10 bits is block-count, 54 bits is block
+	 * offset.  Blocks are sectors unless bblog->shift makes them bigger
+	 */
+	bbp = (__u64*)bbl;
+	printf("Bad-blocks on %s:\n", devname);
+	for (i = 0; i < size/8; i++, bbp++) {
+		__u64 bb = __le64_to_cpu(*bbp);
+		int count = bb & 0x3ff;
+		unsigned long long sector = bb >> 10;
+
+		if (bb + 1 == 0)
+			break;
+
+		sector <<= sb->bblog_shift;
+		count <<= sb->bblog_shift;
+
+		printf("%20llu for %d sectors\n", sector, count);
+	}
+	return 0;
+}
+
 #endif
 
 static int match_home1(struct supertype *st, char *homehost)
@@ -2049,6 +2102,7 @@ struct superswitch super1 = {
 	.write_init_super = write_init_super1,
 	.validate_geometry = validate_geometry1,
 	.add_to_super = add_to_super1,
+	.examine_badblocks = examine_badblocks_super1,
 #endif
 	.match_home = match_home1,
 	.uuid_from_super = uuid_from_super1,