[PATCH parted] dasd: Fix ped_disk_new_fresh() to not read old data from disk (rh533808)

[Hans de Goede]

dasd_write(), was reading the volume label from the disk (trough
fdasd_check_volume()) and later writing it back again, this is fine for
existing dasd labels, but when creating a fresh label, this would
also cause the old volume label to be re-used, and if the old label
was corrupt, it would cause fdasd_check_volume() and thus dasd_write()
to fail.

* libparted/arch/linux.c (toplevel): include fdasd.h.
(init_dasd): Do BIODASDINFO ioctl, and store the dasd devno in
arch_specific.
(init_dasd): Remove dead (never reached) code.
* libparted/arch/linux.h (struct _LinuxSpecific): Add devno member.
* libparted/labels/dasd.c (DasdDiskSpecific): add vlabel member.
(dasd_alloc): Init DasdDiskSpecific.vlabel for fresh disks
(dasd_read): Store read vlabel in DasdDiskSpecific.vlabel.
(dasd_write): Write DasdDiskSpecific.vlabel instead of on disk vlabel.
---
 libparted/arch/linux.c  |   16 +++++++++++-----
 libparted/arch/linux.h  |    1 +
 libparted/labels/dasd.c |   20 ++++++++++++++++----
 3 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/libparted/arch/linux.c b/libparted/arch/linux.c
index d5d3597..18bdb0d 100644
--- a/libparted/arch/linux.c
+++ b/libparted/arch/linux.c
@@ -22,6 +22,9 @@
 
 #include <parted/parted.h>
 #include <parted/debug.h>
+#if defined __s390__ || defined __s390x__
+#include <parted/fdasd.h>
+#endif
 
 #include <ctype.h>
 #include <errno.h>
@@ -1090,7 +1093,7 @@ init_dasd (PedDevice* dev, const char* model_name)
 {
         struct stat             dev_stat;
         struct hd_geometry      geo;
-        char *errstr = 0;
+        dasd_information_t dasd_info;
 
         if (!_device_stat (dev, &dev_stat))
                 goto error;
@@ -1126,15 +1129,18 @@ init_dasd (PedDevice* dev, const char* model_name)
                 dev->hw_geom = dev->bios_geom;
         }
 
+        if (!ioctl(arch_specific->fd, BIODASDINFO, &dasd_info)) {
+                arch_specific->devno = dasd_info.devno;
+        } else {
+                arch_specific->devno = arch_specific->major * 256 +
+                                       arch_specific->minor;
+        }
+
         dev->model = strdup (model_name);
 
         ped_device_close (dev);
         return 1;
 
-        ped_exception_throw ( PED_EXCEPTION_ERROR,
-                              PED_EXCEPTION_IGNORE_CANCEL,
-                              errstr );
-
 error_close_dev:
         ped_device_close (dev);
 error:
diff --git a/libparted/arch/linux.h b/libparted/arch/linux.h
index 7036886..dc4e076 100644
--- a/libparted/arch/linux.h
+++ b/libparted/arch/linux.h
@@ -33,6 +33,7 @@ struct _LinuxSpecific {
        char*   dmtype;         /**< device map target type */
 #if defined __s390__ || defined __s390x__
        unsigned int real_sector_size;
+       unsigned int devno;
 #endif
 #if USE_BLKID
         blkid_probe probe;
diff --git a/libparted/labels/dasd.c b/libparted/labels/dasd.c
index 56b8131..d5392d9 100644
--- a/libparted/labels/dasd.c
+++ b/libparted/labels/dasd.c
@@ -70,6 +70,7 @@ typedef struct {
 
 typedef struct {
        unsigned int format_type;
+       volume_label_t vlabel;
 } DasdDiskSpecific;
 
 static int dasd_probe (const PedDevice *dev);
@@ -146,6 +147,7 @@ dasd_alloc (const PedDevice* dev)
        PedDisk* disk;
        LinuxSpecific* arch_specific;
        DasdDiskSpecific *disk_specific;
+       char volser[7];
 
        PED_ASSERT (dev != NULL, return NULL);
 
@@ -163,6 +165,15 @@ dasd_alloc (const PedDevice* dev)
        /* CDL format, newer */
        disk_specific->format_type = 2;
 
+       /* Setup volume label (for fresh disks) */
+       snprintf(volser, sizeof(volser), "0X%04X", arch_specific->devno);
+       vtoc_volume_label_init(&disk_specific->vlabel);
+       vtoc_volume_label_set_key(&disk_specific->vlabel, "VOL1");
+       vtoc_volume_label_set_label(&disk_specific->vlabel, "VOL1");
+       vtoc_volume_label_set_volser(&disk_specific->vlabel, volser);
+       vtoc_set_cchhb(&disk_specific->vlabel.vtoc,
+                      VTOC_START_CC, VTOC_START_HH, 0x01);
+
        return disk;
 }
 
@@ -296,6 +307,9 @@ dasd_read (PedDisk* disk)
        if (fdasd_check_volume(&anchor, arch_specific->fd))
                goto error_close_dev;
 
+       /* Save volume label (read by fdasd_check_volume) for writing */
+       memcpy(&disk_specific->vlabel, anchor.vlabel, sizeof(volume_label_t));
+
        if ((anchor.geo.cylinders * anchor.geo.heads) > BIG_DISK_SIZE)
                anchor.big_disk++;
 
@@ -556,10 +570,8 @@ dasd_write (const PedDisk* disk)
        /* initialize the anchor */
        fdasd_initialize_anchor(&anchor);
        fdasd_get_geometry(&anchor, arch_specific->fd);
-
-       /* check dasd for labels and vtoc */
-       if (fdasd_check_volume(&anchor, arch_specific->fd))
-               goto error;
+       memcpy(anchor.vlabel, &disk_specific->vlabel, sizeof(volume_label_t));
+       anchor.vlabel_changed++;
 
        if ((anchor.geo.cylinders * anchor.geo.heads) > BIG_DISK_SIZE)
                anchor.big_disk++;
-- 
1.6.5.2