1 files changed, 141 insertions, 34 deletions

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index e8ef27d7ef61..168f25e4aaa3 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -163,9 +163,11 @@ static const char *st_formats[] = {
 
 static int debugging = DEBUG;
 
+/* Setting these non-zero may risk recognizing resets */
 #define MAX_RETRIES 0
 #define MAX_WRITE_RETRIES 0
 #define MAX_READY_RETRIES 0
+
 #define NO_TAPE  NOT_READY
 
 #define ST_TIMEOUT (900 * HZ)
@@ -357,10 +359,18 @@ static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
 {
 	int result = SRpnt->result;
 	u8 scode;
+	unsigned int ctr;
 	DEB(const char *stp;)
 	char *name = STp->name;
 	struct st_cmdstatus *cmdstatp;
 
+	ctr = scsi_get_ua_por_ctr(STp->device);
+	if (ctr != STp->por_ctr) {
+		STp->por_ctr = ctr;
+		STp->pos_unknown = 1; /* ASC => power on / reset */
+		st_printk(KERN_WARNING, STp, "Power on/reset recognized.");
+	}
+
 	if (!result)
 		return 0;
 
@@ -413,10 +423,11 @@ static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
 	if (cmdstatp->have_sense &&
 	    cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
 		STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
-	if (cmdstatp->have_sense && scode == UNIT_ATTENTION && cmdstatp->sense_hdr.asc == 0x29)
+	if (cmdstatp->have_sense && scode == UNIT_ATTENTION &&
+		cmdstatp->sense_hdr.asc == 0x29 && !STp->pos_unknown) {
 		STp->pos_unknown = 1; /* ASC => power on / reset */
-
-	STp->pos_unknown |= STp->device->was_reset;
+		st_printk(KERN_WARNING, STp, "Power on/reset recognized.");
+	}
 
 	if (cmdstatp->have_sense &&
 	    scode == RECOVERED_ERROR
@@ -952,7 +963,6 @@ static void reset_state(struct scsi_tape *STp)
 		STp->partition = find_partition(STp);
 		if (STp->partition < 0)
 			STp->partition = 0;
-		STp->new_partition = STp->partition;
 	}
 }
 
@@ -969,6 +979,7 @@ static int test_ready(struct scsi_tape *STp, int do_wait)
 {
 	int attentions, waits, max_wait, scode;
 	int retval = CHKRES_READY, new_session = 0;
+	unsigned int ctr;
 	unsigned char cmd[MAX_COMMAND_SIZE];
 	struct st_request *SRpnt = NULL;
 	struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
@@ -1025,11 +1036,23 @@ static int test_ready(struct scsi_tape *STp, int do_wait)
 			}
 		}
 
+		ctr = scsi_get_ua_new_media_ctr(STp->device);
+		if (ctr != STp->new_media_ctr) {
+			STp->new_media_ctr = ctr;
+			new_session = 1;
+			DEBC_printk(STp, "New tape session.");
+		}
+
 		retval = (STp->buffer)->syscall_result;
 		if (!retval)
 			retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
 		break;
 	}
+	if (STp->first_tur) {
+		/* Don't set pos_unknown right after device recognition */
+		STp->pos_unknown = 0;
+		STp->first_tur = 0;
+	}
 
 	if (SRpnt != NULL)
 		st_release_request(SRpnt);
@@ -2892,7 +2915,6 @@ static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned lon
 			timeout = STp->long_timeout * 8;
 
 		DEBC_printk(STp, "Erasing tape.\n");
-		fileno = blkno = at_sm = 0;
 		break;
 	case MTSETBLK:		/* Set block length */
 	case MTSETDENSITY:	/* Set tape density */
@@ -2925,14 +2947,17 @@ static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned lon
 		if (cmd_in == MTSETDENSITY) {
 			(STp->buffer)->b_data[4] = arg;
 			STp->density_changed = 1;	/* At least we tried ;-) */
+			STp->changed_density = arg;
 		} else if (cmd_in == SET_DENS_AND_BLK)
 			(STp->buffer)->b_data[4] = arg >> 24;
 		else
 			(STp->buffer)->b_data[4] = STp->density;
 		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
 			ltmp = arg & MT_ST_BLKSIZE_MASK;
-			if (cmd_in == MTSETBLK)
+			if (cmd_in == MTSETBLK) {
 				STp->blksize_changed = 1; /* At least we tried ;-) */
+				STp->changed_blksize = arg;
+			}
 		} else
 			ltmp = STp->block_size;
 		(STp->buffer)->b_data[9] = (ltmp >> 16);
@@ -3079,7 +3104,9 @@ static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned lon
 			   cmd_in == MTSETDRVBUFFER ||
 			   cmd_in == SET_DENS_AND_BLK) {
 			if (cmdstatp->sense_hdr.sense_key == ILLEGAL_REQUEST &&
-			    !(STp->use_pf & PF_TESTED)) {
+				cmdstatp->sense_hdr.asc == 0x24 &&
+				(STp->device)->scsi_level <= SCSI_2 &&
+				!(STp->use_pf & PF_TESTED)) {
 				/* Try the other possible state of Page Format if not
 				   already tried */
 				STp->use_pf = (STp->use_pf ^ USE_PF) | PF_TESTED;
@@ -3499,8 +3526,64 @@ static int partition_tape(struct scsi_tape *STp, int size)
 out:
 	return result;
 }
-
 
+/*
+ * Handles any extra state needed for ioctls which are not st-specific.
+ * Called with the scsi_tape lock held, released before return
+ */
+static long st_common_ioctl(struct scsi_tape *STp, struct st_modedef *STm,
+			    struct file *file, unsigned int cmd_in,
+			    unsigned long arg)
+{
+	int i, retval = 0;
+
+	if (!STm->defined) {
+		retval = -ENXIO;
+		goto out;
+	}
+
+	switch (cmd_in) {
+	case SCSI_IOCTL_GET_IDLUN:
+	case SCSI_IOCTL_GET_BUS_NUMBER:
+	case SCSI_IOCTL_GET_PCI:
+		break;
+	case SG_IO:
+	case SCSI_IOCTL_SEND_COMMAND:
+	case CDROM_SEND_PACKET:
+		if (!capable(CAP_SYS_RAWIO)) {
+			retval = -EPERM;
+			goto out;
+		}
+		fallthrough;
+	default:
+		if ((i = flush_buffer(STp, 0)) < 0) {
+			retval = i;
+			goto out;
+		} else { /* flush_buffer succeeds */
+			if (STp->can_partitions) {
+				i = switch_partition(STp);
+				if (i < 0) {
+					retval = i;
+					goto out;
+				}
+			}
+		}
+	}
+	mutex_unlock(&STp->lock);
+
+	retval = scsi_ioctl(STp->device, file->f_mode & FMODE_WRITE,
+			    cmd_in, (void __user *)arg);
+	if (!retval && cmd_in == SCSI_IOCTL_STOP_UNIT) {
+		/* unload */
+		STp->rew_at_close = 0;
+		STp->ready = ST_NO_TAPE;
+	}
+
+	return retval;
+out:
+	mutex_unlock(&STp->lock);
+	return retval;
+}
 
 /* The ioctl command */
 static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
@@ -3538,6 +3621,15 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
 	if (retval)
 		goto out;
 
+	switch (cmd_in) {
+	case MTIOCPOS:
+	case MTIOCGET:
+	case MTIOCTOP:
+		break;
+	default:
+		return st_common_ioctl(STp, STm, file, cmd_in, arg);
+	}
+
 	cmd_type = _IOC_TYPE(cmd_in);
 	cmd_nr = _IOC_NR(cmd_in);
 
@@ -3631,9 +3723,23 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
 				retval = (-EIO);
 				goto out;
 			}
-			reset_state(STp);
-			/* remove this when the midlevel properly clears was_reset */
-			STp->device->was_reset = 0;
+			reset_state(STp); /* Clears pos_unknown */
+
+			/* Fix the device settings after reset, ignore errors */
+			if (mtc.mt_op == MTREW || mtc.mt_op == MTSEEK ||
+				mtc.mt_op == MTEOM) {
+				if (STp->can_partitions) {
+					/* STp->new_partition contains the
+					 *  latest partition set
+					 */
+					STp->partition = 0;
+					switch_partition(STp);
+				}
+				if (STp->density_changed)
+					st_int_ioctl(STp, MTSETDENSITY, STp->changed_density);
+				if (STp->blksize_changed)
+					st_int_ioctl(STp, MTSETBLK, STp->changed_blksize);
+			}
 		}
 
 		if (mtc.mt_op != MTNOP && mtc.mt_op != MTSETBLK &&
@@ -3835,29 +3941,7 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
 		}
 		mt_pos.mt_blkno = blk;
 		retval = put_user_mtpos(p, &mt_pos);
-		goto out;
-	}
-	mutex_unlock(&STp->lock);
-
-	switch (cmd_in) {
-	case SG_IO:
-	case SCSI_IOCTL_SEND_COMMAND:
-	case CDROM_SEND_PACKET:
-		if (!capable(CAP_SYS_RAWIO))
-			return -EPERM;
-		break;
-	default:
-		break;
-	}
-
-	retval = scsi_ioctl(STp->device, file->f_mode & FMODE_WRITE, cmd_in, p);
-	if (!retval && cmd_in == SCSI_IOCTL_STOP_UNIT) {
-		/* unload */
-		STp->rew_at_close = 0;
-		STp->ready = ST_NO_TAPE;
 	}
-	return retval;
-
  out:
 	mutex_unlock(&STp->lock);
 	return retval;
@@ -4117,7 +4201,7 @@ static void validate_options(void)
  */
 static int __init st_setup(char *str)
 {
-	int i, len, ints[5];
+	int i, len, ints[ARRAY_SIZE(parms) + 1];
 	char *stp;
 
 	stp = get_options(str, ARRAY_SIZE(ints), ints);
@@ -4328,6 +4412,7 @@ static int st_probe(struct device *dev)
 	blk_queue_rq_timeout(tpnt->device->request_queue, ST_TIMEOUT);
 	tpnt->long_timeout = ST_LONG_TIMEOUT;
 	tpnt->try_dio = try_direct_io;
+	tpnt->first_tur = 1;
 
 	for (i = 0; i < ST_NBR_MODES; i++) {
 		STm = &(tpnt->modes[i]);
@@ -4378,6 +4463,9 @@ static int st_probe(struct device *dev)
 		goto out_idr_remove;
 	}
 
+	tpnt->new_media_ctr = scsi_get_ua_new_media_ctr(SDp);
+	tpnt->por_ctr = scsi_get_ua_por_ctr(SDp);
+
 	dev_set_drvdata(dev, tpnt);
 
 
@@ -4659,6 +4747,24 @@ options_show(struct device *dev, struct device_attribute *attr, char *buf)
 }
 static DEVICE_ATTR_RO(options);
 
+/**
+ * position_lost_in_reset_show - Value 1 indicates that reads, writes, etc.
+ * are blocked because a device reset has occurred and no operation positioning
+ * the tape has been issued.
+ * @dev: struct device
+ * @attr: attribute structure
+ * @buf: buffer to return formatted data in
+ */
+static ssize_t position_lost_in_reset_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct st_modedef *STm = dev_get_drvdata(dev);
+	struct scsi_tape *STp = STm->tape;
+
+	return sprintf(buf, "%d", STp->pos_unknown);
+}
+static DEVICE_ATTR_RO(position_lost_in_reset);
+
 /* Support for tape stats */
 
 /**
@@ -4843,6 +4949,7 @@ static struct attribute *st_dev_attrs[] = {
 	&dev_attr_default_density.attr,
 	&dev_attr_default_compression.attr,
 	&dev_attr_options.attr,
+	&dev_attr_position_lost_in_reset.attr,
 	NULL,
 };