From 3bc9fef9cc1e4047c3a3c51d84cc1c5d2ef03cea Mon Sep 17 00:00:00 2001 From: Stefan Haberland Date: Thu, 20 Sep 2012 18:37:36 +0200 Subject: [PATCH] s390/dasd: check count address during online setting A common way to prepare a z/VM mini disk is to format the real device with a z/VM tool like CPFMTXA and then define a mini disk that excludes the first cylinder, i.e. the cylinder 0 of the virtual disk is located at cylinder 1 of the real device. The DASD device driver will recognize such a mini disk as formatted, as the uniform record layout on the disk matches that of an LDL formatted device. However, the cylinder value in the 'count' field of the ECKD records matches the geometry of the real device, and not that of the mini disk, so I/O requests will fail with 'record not found' errors. To make the mini disk usable, it needs to be formatted with a tool like dasdfmt. To enable tools like distribution installation tools to recognize this situation, the DASD device driver should report such a mini disk as 'not formatted'. To this end we need to extend the device recognition code to check not just for proper record sizes, but also for proper cylinder/head/record values. Signed-off-by: Stefan Haberland Reviewed-by: Stefan Weinhuber Signed-off-by: Martin Schwidefsky --- drivers/s390/block/dasd_eckd.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c index e1bb930124dd..108332b44d98 100644 --- a/drivers/s390/block/dasd_eckd.c +++ b/drivers/s390/block/dasd_eckd.c @@ -139,6 +139,10 @@ dasd_eckd_set_online(struct ccw_device *cdev) static const int sizes_trk0[] = { 28, 148, 84 }; #define LABEL_SIZE 140 +/* head and record addresses of count_area read in analysis ccw */ +static const int count_area_head[] = { 0, 0, 0, 0, 2 }; +static const int count_area_rec[] = { 1, 2, 3, 4, 1 }; + static inline unsigned int round_up_multiple(unsigned int no, unsigned int mult) { @@ -1939,7 +1943,10 @@ static int dasd_eckd_end_analysis(struct dasd_block *block) count_area = NULL; for (i = 0; i < 3; i++) { if (private->count_area[i].kl != 4 || - private->count_area[i].dl != dasd_eckd_cdl_reclen(i) - 4) { + private->count_area[i].dl != dasd_eckd_cdl_reclen(i) - 4 || + private->count_area[i].cyl != 0 || + private->count_area[i].head != count_area_head[i] || + private->count_area[i].record != count_area_rec[i]) { private->uses_cdl = 0; break; } @@ -1951,7 +1958,10 @@ static int dasd_eckd_end_analysis(struct dasd_block *block) for (i = 0; i < 5; i++) { if ((private->count_area[i].kl != 0) || (private->count_area[i].dl != - private->count_area[0].dl)) + private->count_area[0].dl) || + private->count_area[i].cyl != 0 || + private->count_area[i].head != count_area_head[i] || + private->count_area[i].record != count_area_rec[i]) break; } if (i == 5) -- 2.39.5