s390: improve/correct DASD support

The long title would be "corrections to partition size and location
calculations for type 1 partitions for s390 dasd".

This could be treated as two separate fixes, one to make corrections
for LDL formatted disks and one to add support for CMS formatted
disks.  I see CMS formatted disks as a variant of LDL formatted
disks, with the additional twist that CMS formatted disks can
be reserved or recomped, which LDL formatted disks cannot be.
This affects the size and location of the partition.

With these patches, parted matches the behavior of the Linux kernel
in recognizing partitions on CMS- and LDL-formatted disks, as documented
in the Linux kernel source code in routine fs/partitions/ibm.c.
Calculation of the metadata has also been changed so that parted will
show no free space on such a disk.  In some cases there are now two
non-contiguous metadata extents: one at the beginning of the disk and
one at the end.

As before, parted only supports CKD DASD using the ECKD driver.
FBA DASD and CKD DASD using the DIAG driver are still not supported.

In my regression testing I have discovered some problems in the area
of recognizing file system options.  However, since I can duplicate
these errors on a version of parted which does not contain my changes,
I have concluded that my changes did not cause this and therefore
this is an unrelated bug.

4 files changed, 166 insertions, 25 deletions

diff --git a/include/parted/vtoc.h b/include/parted/vtoc.h
index 6b41584..d79ce39 100644
--- a/include/parted/vtoc.h
+++ b/include/parted/vtoc.h
@@ -49,6 +49,8 @@ typedef struct cchhb            cchhb_t;
 typedef struct cchh             cchh_t;
 typedef struct labeldate        labeldate_t;
 typedef struct volume_label     volume_label_t;
+typedef struct cms_volume_label cms_volume_label_t;
+typedef struct ldl_volume_label ldl_volume_label_t;
 typedef struct extent           extent_t;
 typedef struct dev_const        dev_const_t;
 typedef struct format1_label    format1_label_t;
@@ -81,7 +83,7 @@ struct __attribute__ ((packed)) labeldate {
 
 struct __attribute__ ((packed)) volume_label {
 	char volkey[4];         /* volume key = volume label                 */
-	char vollbl[4];	        /* volume label                              */
+	char vollbl[4];	        /* volume label ("VOL1" in EBCDIC)           */
 	char volid[6];	        /* volume identifier                         */
 	u_int8_t security;	/* security byte                             */
 	cchhb_t vtoc;           /* VTOC address                              */
@@ -93,6 +95,58 @@ struct __attribute__ ((packed)) volume_label {
 	char res2[4];	        /* reserved                                  */
 	char lvtoc[14];	        /* owner code for LVTOC                      */
 	char res3[29];	        /* reserved                                  */
+        char fudge[4];          /* filler to match length of ldl label       */
+};
+
+struct __attribute__ ((packed)) ldl_volume_label {
+	char vollbl[4];         /* Label identifier ("LNX1" in EBCDIC)       */
+        char volid[6];          /* Volume identifier                         */
+        char res3[69];          /* Reserved field                            */
+        char ldl_version[1];    /* Version number, valid for ldl format      */
+        u_int64_t formatted_blocks;  /* valid when ldl_version >= "2" (in
+                                        EBCDIC)                              */
+};
+
+/*
+ * See:
+ *	z/VM V5R2.0 CMS Planning and Administration
+ *	SC24-6078-01
+ *	What CMS Does / Disk and File Management / Disk File Format
+ * http://publib.boulder.ibm.com/infocenter/zvm/v5r4/topic/com.ibm.zvm.v54.dmsd1/hcsg2b1018.htm
+ */
+struct __attribute__ ((packed)) cms_volume_label {
+	char label_id[4];       /* Label identifier ("CMS1" in EBCDIC)       */
+	char vol_id[6];         /* Volume identifier                         */
+	char version_id[2];     /* Version identifier ("\0\0")               */
+	u_int32_t block_size;   /* Disk block size (512, 1024, 2048 or 4096) */
+	u_int32_t origin_ptr;   /* Disk origin pointer (4 or 5)              */
+	u_int32_t usable_count; /* Number of usable cylinders/blocks         */
+	u_int32_t formatted_count; /* Max # of formatted cylinders/blocks    */
+	u_int32_t block_count;  /* Disk size in CMS blocks                   */
+	u_int32_t used_count;   /* Number of CMS blocks in use               */
+	u_int32_t fst_size;     /* File Status Table (FST) size (64)         */
+	u_int32_t fst_count;    /* Number of FSTs per CMS block              */
+	char format_date[6];    /* Disk FORMAT date (YYMMDDhhmmss)           */
+	char reserved1[2];      /* Reserved fields.
+	                           The low-order bit of the first byte is a
+	                           century flag.  0 = 1900s, 1 = 2000s.
+	                           It is used in conjunction with
+	                           "format_date" to determine the
+	                           four-digit year.                          */
+	u_int32_t disk_offset;  /* Offset in blocks to the start of the
+	                           reserved file when the disk is reserved.
+	                           This is the number of blocks to skip
+	                           before the partition starts.              */
+	u_int32_t map_block;    /* Allocation map block with next hole       */
+	u_int32_t hblk_disp;    /* Displacement in HBLK data of next hole    */
+	u_int32_t user_disp;    /* Disp into user part of allocation map     */
+	u_int32_t open_files;   /* Count of SFS open files for this ADT.
+	                           open_files is not really part of the
+	                           volume label.  It is not used for
+	                           minidisks.                                */
+	char segment_name[8];   /* Name of the shared segment.
+	                           segment_name is not really part of the
+	                           volume label.  It is not stored on disk.  */
 };
 
 struct __attribute__ ((packed)) extent {
diff --git a/libparted/labels/dasd.c b/libparted/labels/dasd.c
index 53c9c90..d88816a 100644
--- a/libparted/labels/dasd.c
+++ b/libparted/labels/dasd.c
@@ -286,18 +286,58 @@ dasd_read (PedDisk* disk)
 
 	ped_disk_delete_all (disk);
 
-	if (strncmp(anchor.vlabel->volkey,
-				vtoc_ebcdic_enc ("LNX1", str, 4), 4) == 0) {
+	bool is_ldl = strncmp(anchor.vlabel->volkey,
+			 vtoc_ebcdic_enc("LNX1", str, 4), 4) == 0;
+	bool is_cms = strncmp(anchor.vlabel->volkey,
+			 vtoc_ebcdic_enc("CMS1", str, 4), 4) == 0;
+	if (is_ldl || is_cms) {
 		DasdPartitionData* dasd_data;
 
-		/* LDL format, old one */
+		union vollabel {
+			volume_label_t unused;
+			ldl_volume_label_t ldl;
+			cms_volume_label_t cms;
+		};
+		union vollabel *cms_ptr1 = (union vollabel *) anchor.vlabel;
+		cms_volume_label_t *cms_ptr = &cms_ptr1->cms;
+		ldl_volume_label_t *ldl_ptr = &cms_ptr1->ldl;
+
 		disk_specific->format_type = 1;
-		start = 24;
-		end = (long long)(long long) anchor.geo.cylinders
-		      * (long long)anchor.geo.heads
-		      * (long long)disk->dev->hw_geom.sectors
-		      * (long long)arch_specific->real_sector_size
-		      / (long long)disk->dev->sector_size - 1;
+		if (is_ldl || cms_ptr->disk_offset == 0)
+			start = (long long) arch_specific->real_sector_size
+				/ (long long)disk->dev->sector_size * 3;
+		else
+			start = (long long) arch_specific->real_sector_size
+				/ (long long) disk->dev->sector_size
+				* (long long) cms_ptr->disk_offset;
+		if (is_ldl)
+		   if (ldl_ptr->ldl_version >= 0xf2)
+		      end = (long long) arch_specific->real_sector_size
+			    / (long long) disk->dev->sector_size
+			    * (long long) ldl_ptr->formatted_blocks - 1;
+		   else
+		      end = (long long) arch_specific->real_sector_size
+			    / (long long) disk->dev->sector_size
+			    * (long long) anchor.geo.cylinders
+			    * (long long) anchor.geo.heads
+			    * (long long) disk->dev->hw_geom.sectors - 1;
+		else
+		   if (cms_ptr->disk_offset == 0)
+		      end = (long long) arch_specific->real_sector_size
+			    / (long long) disk->dev->sector_size
+			    * (long long) cms_ptr->block_count - 1;
+		   else
+		      /*
+			 Frankly, I do not understand why the last block
+			 of the CMS reserved file is not included in the
+			 partition; but this is the algorithm used by the
+			 Linux kernel.  See fs/partitions/ibm.c in the
+			 Linux kernel source code.
+		      */
+		      end = (long long) arch_specific->real_sector_size
+			    / (long long) disk->dev->sector_size
+			    * (long long) (cms_ptr->block_count - 1) - 1;
+
 		part = ped_partition_new (disk, PED_PARTITION_PROTECTED, NULL, start, end);
 		if (!part)
 			goto error_close_dev;
@@ -856,6 +896,10 @@ dasd_alloc_metadata (PedDisk* disk)
 	PedSector vtoc_end;
 	LinuxSpecific* arch_specific;
 	DasdDiskSpecific* disk_specific;
+	PedPartition* part;
+	PedPartition* new_part2;
+	PedSector trailing_meta_start, trailing_meta_end;
+	struct fdasd_anchor anchor;
 
 	PED_ASSERT (disk != NULL, goto error);
 	PED_ASSERT (disk->dev != NULL, goto error);
@@ -865,9 +909,12 @@ dasd_alloc_metadata (PedDisk* disk)
 
 	constraint_any = ped_constraint_any (disk->dev);
 
-	/* If formated in LDL, the real partition starts at sector 24. */
-	if (disk_specific->format_type == 1)
-		vtoc_end = 23;
+	/* For LDL or CMS, the leading metadata ends at the sector before
+	   the start of the first partition */
+	if (disk_specific->format_type == 1) {
+	        part = ped_disk_get_partition(disk, 1);
+		vtoc_end = part->geom.start - 1;
+	}
 	else {
                 if (disk->dev->type == PED_DEVICE_FILE)
                         arch_specific->real_sector_size = disk->dev->sector_size;
@@ -886,6 +933,41 @@ dasd_alloc_metadata (PedDisk* disk)
 		goto error;
 	}
 
+	if (disk_specific->format_type == 1) {
+	   /*
+	      For LDL or CMS there may be trailing metadata as well.
+	      For example: the last block of a CMS reserved file,
+	      the "recomp" area of a CMS minidisk that has been
+	      formatted and then formatted again with the RECOMP
+	      option specifying fewer than the maximum number of
+	      cylinders, a disk that was formatted at one size,
+	      backed up, then restored to a larger size disk, etc.
+	   */
+	   trailing_meta_start = part->geom.end + 1;
+	   fdasd_initialize_anchor(&anchor);
+	   fdasd_get_geometry(disk->dev, &anchor, arch_specific->fd);
+	   trailing_meta_end = (long long) arch_specific->real_sector_size
+		/ (long long) disk->dev->sector_size
+		* (long long) anchor.geo.cylinders
+		* (long long) anchor.geo.heads
+		* (long long) disk->dev->hw_geom.sectors - 1;
+	   fdasd_cleanup(&anchor);
+	   if (trailing_meta_end >= trailing_meta_start) {
+		new_part2 = ped_partition_new (disk,PED_PARTITION_METADATA,
+		   NULL, trailing_meta_start, trailing_meta_end);
+		if (!new_part2) {
+		   ped_partition_destroy (new_part);
+		   goto error;
+		}
+		if (!ped_disk_add_partition (disk, new_part2,
+		   constraint_any)) {
+		   ped_partition_destroy (new_part2);
+		   ped_partition_destroy (new_part);
+		   goto error;
+		}
+	   }
+	}
+
 	ped_constraint_destroy (constraint_any);
 	return 1;
 
diff --git a/libparted/labels/fdasd.c b/libparted/labels/fdasd.c
index 6397f27..62baa52 100644
--- a/libparted/labels/fdasd.c
+++ b/libparted/labels/fdasd.c
@@ -698,15 +698,15 @@ fdasd_valid_vtoc_pointer(fdasd_anchor_t *anc, unsigned long b, int fd)
 	/* VOL1 label contains valid VTOC pointer */
 	vtoc_read_label (fd, b, NULL, anc->f4, NULL, NULL);
 
-	if (anc->f4->DS4IDFMT != 0xf4) {
-		if (strncmp(anc->vlabel->volkey,vtoc_ebcdic_enc("LNX1",str,4),4) == 0)
-			return 0;
-		fdasd_error(anc, wrong_disk_format, _("Invalid VTOC."));
-	} else {
+	if (anc->f4->DS4IDFMT == 0xf4) {
 		fdasd_process_valid_vtoc (anc, b, fd);
+		return 0;
 	}
+	if (strncmp(anc->vlabel->volkey, vtoc_ebcdic_enc("LNX1",str,4),4) == 0 ||
+	    strncmp(anc->vlabel->volkey, vtoc_ebcdic_enc("CMS1",str,4),4) == 0)
+		return 0;
 
-	return 0;
+	fdasd_error(anc, wrong_disk_format, _("Invalid VTOC."));
 }
 
 /*
@@ -737,7 +737,8 @@ fdasd_check_volume (fdasd_anchor_t *anc, int fd)
 		} else {
 			return 1;
 		}
-	} else if (strncmp (v->volkey, vtoc_ebcdic_enc ("LNX1", str, 4), 4) == 0) {
+	} else if (strncmp (v->volkey, vtoc_ebcdic_enc ("LNX1", str, 4), 4) == 0 ||
+	           strncmp (v->volkey, vtoc_ebcdic_enc ("CMS1", str, 4), 4) == 0) {
 		return 0;
 	}
 
diff --git a/libparted/labels/vtoc.c b/libparted/labels/vtoc.c
index 3742160..3114d3f 100644
--- a/libparted/labels/vtoc.c
+++ b/libparted/labels/vtoc.c
@@ -150,7 +150,7 @@ enum failure {
 	unable_to_read
 };
 
-static char buffer[85];
+static char buffer[89];
 
 static void
 vtoc_error (enum failure why, char const *s1, char const *s2)
@@ -257,7 +257,7 @@ void
 vtoc_volume_label_init (volume_label_t *vlabel)
 {
 	PDEBUG
-	sprintf(buffer, "%84s", " ");
+	sprintf(buffer, "%88s", " ");
 	vtoc_ebcdic_enc(buffer, buffer, sizeof *vlabel);
 	memcpy(vlabel, buffer, sizeof *vlabel);
 }
@@ -279,7 +279,9 @@ vtoc_read_volume_label (int f, unsigned long vlabel_start,
 	}
 
 	rc = read(f, vlabel, sizeof(volume_label_t));
-	if (rc != sizeof(volume_label_t)) {
+	if (rc != sizeof(volume_label_t) &&
+	/* For CDL we ask to read 88 bytes, but only get 84 */
+            rc != sizeof(volume_label_t) - 4) {
 		vtoc_error(unable_to_read, "vtoc_read_volume_label",
 			   _("Could not read volume label."));
 		return 1;
@@ -302,8 +304,10 @@ vtoc_write_volume_label (int f, unsigned long vlabel_start,
 		vtoc_error(unable_to_seek, "vtoc_write_volume_label",
 			   _("Could not write volume label."));
 
-	rc = write(f, vlabel, sizeof(volume_label_t));
-	if (rc != sizeof(volume_label_t))
+	rc = write(f, vlabel, sizeof(volume_label_t) - 4);
+	/* Subtract 4 to leave off the "fudge" variable when writing.
+           We only write CDL volume labels, never LDL or CMS.  */
+	if (rc != sizeof(volume_label_t) - 4)
 		vtoc_error(unable_to_write, "vtoc_write_volume_label",
 			   _("Could not write volume label."));