From: Stefan Weinhuber 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(-) Index: quilt-2.6/drivers/s390/block/dasd_diag.c =================================================================== --- quilt-2.6.orig/drivers/s390/block/dasd_diag.c 2009-11-13 15:48:33.000000000 +0100 +++ quilt-2.6/drivers/s390/block/dasd_diag.c 2009-11-13 16:08:13.000000000 +0100 @@ -145,6 +145,15 @@ 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 @@ 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/