From 22825ab7693fd29769518a0d25ba43c01a50092a Mon Sep 17 00:00:00 2001 From: Stefan Weinhuber Date: Mon, 7 Dec 2009 12:51:48 +0100 Subject: [PATCH] [S390] dasd: support DIAG access for read-only devices 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 --- 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 4e49b4a6c880..8174ec921769 100644 --- a/drivers/s390/block/dasd_diag.c +++ b/drivers/s390/block/dasd_diag.c @@ -145,6 +145,15 @@ 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_warn(&device->cdev->dev, "DIAG ERP failed with " "rc=%d\n", rc); @@ -433,16 +442,20 @@ 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_warn(&device->cdev->dev, "DIAG initialization " "failed with rc=%d\n", rc); rc = -EIO; } else { + if (rc == 4) + device->features |= DASD_FEATURE_READONLY; dev_info(&device->cdev->dev, - "New DASD with %ld byte/block, total size %ld KB\n", + "New DASD with %ld byte/block, total size %ld KB%s\n", (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); -- 2.39.2