From 016b73b363d8d717a37e63c267c0c79d40a6d7d3 Mon Sep 17 00:00:00 2001 From: Stefan Weinhuber Date: Mon, 7 Dec 2009 12:51:48 +0100 Subject: S390: dasd: support DIAG access for read-only devices commit 22825ab7693fd29769518a0d25ba43c01a50092a upstream. When a DASD device is used with the DIAG discipline, the DIAG initialization will indicate success or error with a respective return code. So far we have interpreted a return code of 4 as error, but it actually means that the initialization was successful, but the device is read-only. To allow read-only devices to be used with DIAG we need to accept a return code of 4 as success. Re-initialization of the DIAG access is also part of the DIAG error recovery. If we find that the access mode of a device has been changed from writable to read-only while the device was in use, we print an error message. Signed-off-by: Stefan Weinhuber Signed-off-by: Martin Schwidefsky Cc: Stephen Powell Signed-off-by: Greg Kroah-Hartman --- drivers/s390/block/dasd_diag.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/s390/block/dasd_diag.c b/drivers/s390/block/dasd_diag.c index 85fcb4371054..b4ae447a92c8 100644 --- a/drivers/s390/block/dasd_diag.c +++ b/drivers/s390/block/dasd_diag.c @@ -143,6 +143,15 @@ dasd_diag_erp(struct dasd_device *device) mdsk_term_io(device); rc = mdsk_init_io(device, device->block->bp_block, 0, NULL); + if (rc == 4) { + if (!(device->features & DASD_FEATURE_READONLY)) { + dev_warn(&device->cdev->dev, + "The access mode of a DIAG device changed" + " to read-only"); + device->features |= DASD_FEATURE_READONLY; + } + rc = 0; + } if (rc) DEV_MESSAGE(KERN_WARNING, device, "DIAG ERP unsuccessful, " "rc=%d", rc); @@ -432,16 +441,20 @@ dasd_diag_check_device(struct dasd_device *device) for (sb = 512; sb < bsize; sb = sb << 1) block->s2b_shift++; rc = mdsk_init_io(device, block->bp_block, 0, NULL); - if (rc) { + if (rc && (rc != 4)) { DEV_MESSAGE(KERN_WARNING, device, "DIAG initialization " "failed (rc=%d)", rc); rc = -EIO; } else { + if (rc == 4) + device->features |= DASD_FEATURE_READONLY; DEV_MESSAGE(KERN_INFO, device, - "(%ld B/blk): %ldkB", + "(%ld B/blk): %ldkB%s", (unsigned long) block->bp_block, (unsigned long) (block->blocks << - block->s2b_shift) >> 1); + block->s2b_shift) >> 1, + (rc == 4) ? ", read-only device" : ""); + rc = 0; } out_label: free_page((long) label); -- cgit v1.2.3