Subject: [PATCH v2] libparted: Fixed bug in initializing FBA devices From: Nageswara R Sastry <[email protected]>
Fixed Block Access (FBA) DASDs are mainframe-specific disk devices that are layed out as a sequence of 512-byte sectors. In contrast to ECKD DASDs, these disks do not require formatting and resemble the LBA layout of non-mainframe disks. Despite this resemblance, the Linux kernel applies special handling during partition detection for FBA DASDs, resulting in a single, immutable partition being reported. While actual FBA DASD hardware is no longer available, the z/VM hypervisor can simulate FBA DASD disks, backed by either ECKD or SCSI devices. * libparted/labels/dasd.c (dasd_alloc): For FBA devices corrected the initilization and calling dasd_read in the case of FBA devices to set the implicit partition. Signed-off-by: Nageswara R Sastry <[email protected]> --- libparted/labels/dasd.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) --- a/libparted/labels/dasd.c +++ b/libparted/labels/dasd.c @@ -150,9 +150,19 @@ dasd_alloc (const PedDevice* dev) return NULL; } - /* CDL format, newer */ - disk_specific->format_type = 2; - disk_specific->label_block = 2; + /* Correct assignment is required to pass the correct values + according to the disk type. For FBA disk values are '1' + and for CDL formatted disk values are '2'*/ + struct fdasd_anchor anchor; + fdasd_initialize_anchor(&anchor); + fdasd_get_geometry(disk->dev, &anchor, arch_specific->fd); + if (anchor.FBA_layout == 1) { + disk_specific->format_type = 1; + disk_specific->label_block = 1; + }else{ + disk_specific->label_block = 2; + disk_specific->format_type = 2; + } /* Setup volume label (for fresh disks) */ snprintf(volser, sizeof(volser), "0X%04X", arch_specific->devno); @@ -163,6 +173,13 @@ dasd_alloc (const PedDevice* dev) vtoc_set_cchhb(&disk_specific->vlabel.vtoc, VTOC_START_CC, VTOC_START_HH, 0x01); + /* Calling dasd_read is required for FBA disks to set + the implicit partition */ + if (anchor.FBA_layout == 1) { + if (!dasd_read(disk)) + dasd_free(disk); + } + return disk; }
