s390/dasd: Add new ioctl BIODASDCHECKFMT

Implement new DASD IOCTL BIODASDCHECKFMT to check a range of tracks on a
DASD volume for correct formatting. The following characteristics are
checked:
- Block size
- ECKD key length
- ECKD record ID
- Number of records per track
Signed-off-by: Jan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/uapi/asm/dasd.h

@@ -187,6 +187,36 @@ typedef struct format_data_t {
 #define DASD_FMT_INT_INVAL  4 /* invalidate tracks */
 #define DASD_FMT_INT_COMPAT 8 /* use OS/390 compatible disk layout */
 
+/*
+ * struct format_check_t
+ * represents all data necessary to evaluate the format of
+ * different tracks of a dasd
+ */
+typedef struct format_check_t {
+	/* Input */
+	struct format_data_t expect;
+
+	/* Output */
+	unsigned int result;		/* Error indication (DASD_FMT_ERR_*) */
+	unsigned int unit;		/* Track that is in error */
+	unsigned int rec;		/* Record that is in error */
+	unsigned int num_records;	/* Records in the track in error */
+	unsigned int blksize;		/* Blocksize of first record in error */
+	unsigned int key_length;	/* Key length of first record in error */
+} format_check_t;
+
+/* Values returned in format_check_t when a format error is detected: */
+/* Too few records were found on a single track */
+#define DASD_FMT_ERR_TOO_FEW_RECORDS	1
+/* Too many records were found on a single track */
+#define DASD_FMT_ERR_TOO_MANY_RECORDS	2
+/* Blocksize/data-length of a record was wrong */
+#define DASD_FMT_ERR_BLKSIZE		3
+/* A record ID is defined by cylinder, head, and record number (CHR). */
+/* On mismatch, this error is set */
+#define DASD_FMT_ERR_RECORD_ID		4
+/* If key-length was != 0 */
+#define DASD_FMT_ERR_KEY_LENGTH		5
 
 /* 
  * struct attrib_data_t
@@ -288,6 +318,8 @@ struct dasd_snid_ioctl_data {
 
 /* Get Sense Path Group ID (SNID) data */
 #define BIODASDSNID    _IOWR(DASD_IOCTL_LETTER, 1, struct dasd_snid_ioctl_data)
+/* Check device format according to format_check_t */
+#define BIODASDCHECKFMT _IOWR(DASD_IOCTL_LETTER, 2, format_check_t)
 
 #define BIODASDSYMMIO  _IOWR(DASD_IOCTL_LETTER, 240, dasd_symmio_parms_t)
 

drivers/s390/block/dasd.c

@@ -1638,6 +1638,9 @@ void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
 	struct dasd_ccw_req *cqr, *next;
 	struct dasd_device *device;
 	unsigned long long now;
+	int nrf_suppressed = 0;
+	int fp_suppressed = 0;
+	u8 *sense = NULL;
 	int expires;
 
 	if (IS_ERR(irb)) {
@@ -1673,7 +1676,23 @@ void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
 			dasd_put_device(device);
 			return;
 		}
-		device->discipline->dump_sense_dbf(device, irb, "int");
+
+		/*
+		 * In some cases 'File Protected' or 'No Record Found' errors
+		 * might be expected and debug log messages for the
+		 * corresponding interrupts shouldn't be written then.
+		 * Check if either of the according suppress bits is set.
+		 */
+		sense = dasd_get_sense(irb);
+		if (sense) {
+			fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
+				test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
+			nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
+				test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
+		}
+		if (!(fp_suppressed || nrf_suppressed))
+			device->discipline->dump_sense_dbf(device, irb, "int");
+
 		if (device->features & DASD_FEATURE_ERPLOG)
 			device->discipline->dump_sense(device, cqr, irb);
 		device->discipline->check_for_device_change(device, cqr, irb);
@@ -2312,6 +2331,7 @@ static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
 {
 	struct dasd_device *device;
 	struct dasd_ccw_req *cqr, *n;
+	u8 *sense = NULL;
 	int rc;
 
 retry:
@@ -2357,6 +2377,20 @@ static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
 
 	rc = 0;
 	list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
+		/*
+		 * In some cases the 'File Protected' or 'Incorrect Length'
+		 * error might be expected and error recovery would be
+		 * unnecessary in these cases.	Check if the according suppress
+		 * bit is set.
+		 */
+		sense = dasd_get_sense(&cqr->irb);
+		if (sense && sense[1] & SNS1_FILE_PROTECTED &&
+		    test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
+			continue;
+		if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
+		    test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
+			continue;
+
 		/*
 		 * for alias devices simplify error recovery and
 		 * return to upper layer

drivers/s390/block/dasd_3990_erp.c

@@ -1367,8 +1367,14 @@ dasd_3990_erp_no_rec(struct dasd_ccw_req * default_erp, char *sense)
 
 	struct dasd_device *device = default_erp->startdev;
 
-	dev_err(&device->cdev->dev,
-		    "The specified record was not found\n");
+	/*
+	 * In some cases the 'No Record Found' error might be expected and
+	 * log messages shouldn't be written then.
+	 * Check if the according suppress bit is set.
+	 */
+	if (!test_bit(DASD_CQR_SUPPRESS_NRF, &default_erp->flags))
+		dev_err(&device->cdev->dev,
+			"The specified record was not found\n");
 
 	return dasd_3990_erp_cleanup(default_erp, DASD_CQR_FAILED);
 
@@ -1393,8 +1399,14 @@ dasd_3990_erp_file_prot(struct dasd_ccw_req * erp)
 
 	struct dasd_device *device = erp->startdev;
 
-	dev_err(&device->cdev->dev, "Accessing the DASD failed because of "
-		"a hardware error\n");
+	/*
+	 * In some cases the 'File Protected' error might be expected and
+	 * log messages shouldn't be written then.
+	 * Check if the according suppress bit is set.
+	 */
+	if (!test_bit(DASD_CQR_SUPPRESS_FP, &erp->flags))
+		dev_err(&device->cdev->dev,
+			"Accessing the DASD failed because of a hardware error\n");
 
 	return dasd_3990_erp_cleanup(erp, DASD_CQR_FAILED);
 

drivers/s390/block/dasd_eckd.h

@@ -35,6 +35,7 @@
 #define DASD_ECKD_CCW_READ_MT		 0x86
 #define DASD_ECKD_CCW_WRITE_KD_MT	 0x8d
 #define DASD_ECKD_CCW_READ_KD_MT	 0x8e
+#define DASD_ECKD_CCW_READ_COUNT_MT	 0x92
 #define DASD_ECKD_CCW_RELEASE		 0x94
 #define DASD_ECKD_CCW_WRITE_FULL_TRACK	 0x95
 #define DASD_ECKD_CCW_READ_CKD_MT	 0x9e

drivers/s390/block/dasd_int.h

@@ -236,6 +236,13 @@ struct dasd_ccw_req {
 					 * stolen. Should not be combined with
 					 * DASD_CQR_FLAGS_USE_ERP
 					 */
+/*
+ * The following flags are used to suppress output of certain errors.
+ * These flags should only be used for format checks!
+ */
+#define DASD_CQR_SUPPRESS_NRF	4	/* Suppress 'No Record Found' error */
+#define DASD_CQR_SUPPRESS_FP	5	/* Suppress 'File Protected' error*/
+#define DASD_CQR_SUPPRESS_IL	6	/* Suppress 'Incorrect Length' error */
 
 /* Signature for error recovery functions. */
 typedef struct dasd_ccw_req *(*dasd_erp_fn_t) (struct dasd_ccw_req *);
@@ -318,7 +325,8 @@ struct dasd_discipline {
 	 * Device operation functions. build_cp creates a ccw chain for
 	 * a block device request, start_io starts the request and
 	 * term_IO cancels it (e.g. in case of a timeout). format_device
-	 * returns a ccw chain to be used to format the device.
+	 * formats the device and check_device_format compares the format of
+	 * a device with the expected format_data.
 	 * handle_terminated_request allows to examine a cqr and prepare
 	 * it for retry.
 	 */
@@ -329,7 +337,9 @@ struct dasd_discipline {
 	int (*term_IO) (struct dasd_ccw_req *);
 	void (*handle_terminated_request) (struct dasd_ccw_req *);
 	int (*format_device) (struct dasd_device *,
-			      struct format_data_t *, int enable_pav);
+			      struct format_data_t *, int);
+	int (*check_device_format)(struct dasd_device *,
+				   struct format_check_t *, int);
 	int (*free_cp) (struct dasd_ccw_req *, struct request *);
 
 	/*

drivers/s390/block/dasd_ioctl.c

@@ -238,6 +238,23 @@ dasd_format(struct dasd_block *block, struct format_data_t *fdata)
 	return rc;
 }
 
+static int dasd_check_format(struct dasd_block *block,
+			     struct format_check_t *cdata)
+{
+	struct dasd_device *base;
+	int rc;
+
+	base = block->base;
+	if (!base->discipline->check_device_format)
+		return -ENOTTY;
+
+	rc = base->discipline->check_device_format(base, cdata, 1);
+	if (rc == -EAGAIN)
+		rc = base->discipline->check_device_format(base, cdata, 0);
+
+	return rc;
+}
+
 /*
  * Format device.
  */
@@ -272,6 +289,47 @@ dasd_ioctl_format(struct block_device *bdev, void __user *argp)
 	}
 	rc = dasd_format(base->block, &fdata);
 	dasd_put_device(base);
+
+	return rc;
+}
+
+/*
+ * Check device format
+ */
+static int dasd_ioctl_check_format(struct block_device *bdev, void __user *argp)
+{
+	struct format_check_t cdata;
+	struct dasd_device *base;
+	int rc = 0;
+
+	if (!argp)
+		return -EINVAL;
+
+	base = dasd_device_from_gendisk(bdev->bd_disk);
+	if (!base)
+		return -ENODEV;
+	if (bdev != bdev->bd_contains) {
+		pr_warn("%s: The specified DASD is a partition and cannot be checked\n",
+			dev_name(&base->cdev->dev));
+		rc = -EINVAL;
+		goto out_err;
+	}
+
+	if (copy_from_user(&cdata, argp, sizeof(cdata))) {
+		rc = -EFAULT;
+		goto out_err;
+	}
+
+	rc = dasd_check_format(base->block, &cdata);
+	if (rc)
+		goto out_err;
+
+	if (copy_to_user(argp, &cdata, sizeof(cdata)))
+		rc = -EFAULT;
+
+out_err:
+	dasd_put_device(base);
+
 	return rc;
 }
 
@@ -519,6 +577,9 @@ int dasd_ioctl(struct block_device *bdev, fmode_t mode,
 	case BIODASDFMT:
 		rc = dasd_ioctl_format(bdev, argp);
 		break;
+	case BIODASDCHECKFMT:
+		rc = dasd_ioctl_check_format(bdev, argp);
+		break;
 	case BIODASDINFO:
 		rc = dasd_ioctl_information(block, cmd, argp);
 		break;