Merge commit 'v2.6.39' into for-2.6.40/core

Since for-2.6.40/core was forked off the 2.6.39 devel tree, we've
had churn in the core area that makes it difficult to handle
patches for eg cfq or blk-throttle. Instead of requiring that they
be based in older versions with bugs that have been fixed later
in the rc cycle, merge in 2.6.39 final.

Also fixes up conflicts in the below files.

Conflicts:
	drivers/block/paride/pcd.c
	drivers/cdrom/viocd.c
	drivers/ide/ide-cd.c

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

11 files changed, 172 insertions, 71 deletions

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 4d2df2f76ea0..86b6f1cc1b10 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -1742,11 +1742,20 @@ int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
 static inline int _dasd_term_running_cqr(struct dasd_device *device)
 {
 	struct dasd_ccw_req *cqr;
+	int rc;
 
 	if (list_empty(&device->ccw_queue))
 		return 0;
 	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
-	return device->discipline->term_IO(cqr);
+	rc = device->discipline->term_IO(cqr);
+	if (!rc)
+		/*
+		 * CQR terminated because a more important request is pending.
+		 * Undo decreasing of retry counter because this is
+		 * not an error case.
+		 */
+		cqr->retries++;
+	return rc;
 }
 
 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
@@ -2314,15 +2323,14 @@ static void dasd_flush_request_queue(struct dasd_block *block)
 
 static int dasd_open(struct block_device *bdev, fmode_t mode)
 {
-	struct dasd_block *block = bdev->bd_disk->private_data;
 	struct dasd_device *base;
 	int rc;
 
-	if (!block)
+	base = dasd_device_from_gendisk(bdev->bd_disk);
+	if (!base)
 		return -ENODEV;
 
-	base = block->base;
-	atomic_inc(&block->open_count);
+	atomic_inc(&base->block->open_count);
 	if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
 		rc = -ENODEV;
 		goto unlock;
@@ -2355,21 +2363,28 @@ static int dasd_open(struct block_device *bdev, fmode_t mode)
 		goto out;
 	}
 
+	dasd_put_device(base);
 	return 0;
 
 out:
 	module_put(base->discipline->owner);
 unlock:
-	atomic_dec(&block->open_count);
+	atomic_dec(&base->block->open_count);
+	dasd_put_device(base);
 	return rc;
 }
 
 static int dasd_release(struct gendisk *disk, fmode_t mode)
 {
-	struct dasd_block *block = disk->private_data;
+	struct dasd_device *base;
 
-	atomic_dec(&block->open_count);
-	module_put(block->base->discipline->owner);
+	base = dasd_device_from_gendisk(disk);
+	if (!base)
+		return -ENODEV;
+
+	atomic_dec(&base->block->open_count);
+	module_put(base->discipline->owner);
+	dasd_put_device(base);
 	return 0;
 }
 
@@ -2378,20 +2393,20 @@ static int dasd_release(struct gendisk *disk, fmode_t mode)
  */
 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 {
-	struct dasd_block *block;
 	struct dasd_device *base;
 
-	block = bdev->bd_disk->private_data;
-	if (!block)
+	base = dasd_device_from_gendisk(bdev->bd_disk);
+	if (!base)
 		return -ENODEV;
-	base = block->base;
 
 	if (!base->discipline ||
-	    !base->discipline->fill_geometry)
+	    !base->discipline->fill_geometry) {
+		dasd_put_device(base);
 		return -EINVAL;
-
-	base->discipline->fill_geometry(block, geo);
-	geo->start = get_start_sect(bdev) >> block->s2b_shift;
+	}
+	base->discipline->fill_geometry(base->block, geo);
+	geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
+	dasd_put_device(base);
 	return 0;
 }
 
@@ -2528,7 +2543,6 @@ void dasd_generic_remove(struct ccw_device *cdev)
 	dasd_set_target_state(device, DASD_STATE_NEW);
 	/* dasd_delete_device destroys the device reference. */
 	block = device->block;
-	device->block = NULL;
 	dasd_delete_device(device);
 	/*
 	 * life cycle of block is bound to device, so delete it after
@@ -2650,7 +2664,6 @@ int dasd_generic_set_offline(struct ccw_device *cdev)
 	dasd_set_target_state(device, DASD_STATE_NEW);
 	/* dasd_delete_device destroys the device reference. */
 	block = device->block;
-	device->block = NULL;
 	dasd_delete_device(device);
 	/*
 	 * life cycle of block is bound to device, so delete it after
diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index 42e1bf35f689..d71511c7850a 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -674,6 +674,36 @@ dasd_device_from_cdev(struct ccw_device *cdev)
 	return device;
 }
 
+void dasd_add_link_to_gendisk(struct gendisk *gdp, struct dasd_device *device)
+{
+	struct dasd_devmap *devmap;
+
+	devmap = dasd_find_busid(dev_name(&device->cdev->dev));
+	if (IS_ERR(devmap))
+		return;
+	spin_lock(&dasd_devmap_lock);
+	gdp->private_data = devmap;
+	spin_unlock(&dasd_devmap_lock);
+}
+
+struct dasd_device *dasd_device_from_gendisk(struct gendisk *gdp)
+{
+	struct dasd_device *device;
+	struct dasd_devmap *devmap;
+
+	if (!gdp->private_data)
+		return NULL;
+	device = NULL;
+	spin_lock(&dasd_devmap_lock);
+	devmap = gdp->private_data;
+	if (devmap && devmap->device) {
+		device = devmap->device;
+		dasd_get_device(device);
+	}
+	spin_unlock(&dasd_devmap_lock);
+	return device;
+}
+
 /*
  * SECTION: files in sysfs
  */
diff --git a/drivers/s390/block/dasd_diag.c b/drivers/s390/block/dasd_diag.c
index 29143eda9dd9..85dddb1e4126 100644
--- a/drivers/s390/block/dasd_diag.c
+++ b/drivers/s390/block/dasd_diag.c
@@ -239,7 +239,6 @@ static void dasd_ext_handler(unsigned int ext_int_code,
 	addr_t ip;
 	int rc;
 
-	kstat_cpu(smp_processor_id()).irqs[EXTINT_DSD]++;
 	switch (ext_int_code >> 24) {
 	case DASD_DIAG_CODE_31BIT:
 		ip = (addr_t) param32;
@@ -250,6 +249,7 @@ static void dasd_ext_handler(unsigned int ext_int_code,
 	default:
 		return;
 	}
+	kstat_cpu(smp_processor_id()).irqs[EXTINT_DSD]++;
 	if (!ip) {		/* no intparm: unsolicited interrupt */
 		DBF_EVENT(DBF_NOTICE, "%s", "caught unsolicited "
 			      "interrupt");
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index db8005d9f2fd..3ebdf5f92f8f 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -2037,7 +2037,7 @@ static void dasd_eckd_check_for_device_change(struct dasd_device *device,
 		return;
 
 	/* summary unit check */
-	if ((sense[7] == 0x0D) &&
+	if ((sense[27] & DASD_SENSE_BIT_0) && (sense[7] == 0x0D) &&
 	    (scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK)) {
 		dasd_alias_handle_summary_unit_check(device, irb);
 		return;
@@ -2053,7 +2053,8 @@ static void dasd_eckd_check_for_device_change(struct dasd_device *device,
 	/* loss of device reservation is handled via base devices only
 	 * as alias devices may be used with several bases
 	 */
-	if (device->block && (sense[7] == 0x3F) &&
+	if (device->block && (sense[27] & DASD_SENSE_BIT_0) &&
+	    (sense[7] == 0x3F) &&
 	    (scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
 	    test_bit(DASD_FLAG_IS_RESERVED, &device->flags)) {
 		if (device->features & DASD_FEATURE_FAILONSLCK)
diff --git a/drivers/s390/block/dasd_genhd.c b/drivers/s390/block/dasd_genhd.c
index 5505bc07e1e7..19a1ff03d65e 100644
--- a/drivers/s390/block/dasd_genhd.c
+++ b/drivers/s390/block/dasd_genhd.c
@@ -73,7 +73,7 @@ int dasd_gendisk_alloc(struct dasd_block *block)
 	if (base->features & DASD_FEATURE_READONLY ||
 	    test_bit(DASD_FLAG_DEVICE_RO, &base->flags))
 		set_disk_ro(gdp, 1);
-	gdp->private_data = block;
+	dasd_add_link_to_gendisk(gdp, base);
 	gdp->queue = block->request_queue;
 	block->gdp = gdp;
 	set_capacity(block->gdp, 0);
diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index df9f6999411d..d1e4f2c1264c 100644
--- a/drivers/s390/block/dasd_int.h
+++ b/drivers/s390/block/dasd_int.h
@@ -686,6 +686,9 @@ struct dasd_device *dasd_device_from_cdev(struct ccw_device *);
 struct dasd_device *dasd_device_from_cdev_locked(struct ccw_device *);
 struct dasd_device *dasd_device_from_devindex(int);
 
+void dasd_add_link_to_gendisk(struct gendisk *, struct dasd_device *);
+struct dasd_device *dasd_device_from_gendisk(struct gendisk *);
+
 int dasd_parse(void);
 int dasd_busid_known(const char *);
 
diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
index 26075e95b1ba..72261e4c516d 100644
--- a/drivers/s390/block/dasd_ioctl.c
+++ b/drivers/s390/block/dasd_ioctl.c
@@ -42,16 +42,22 @@ dasd_ioctl_api_version(void __user *argp)
 static int
 dasd_ioctl_enable(struct block_device *bdev)
 {
-	struct dasd_block *block = bdev->bd_disk->private_data;
+	struct dasd_device *base;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EACCES;
 
-	dasd_enable_device(block->base);
+	base = dasd_device_from_gendisk(bdev->bd_disk);
+	if (!base)
+		return -ENODEV;
+
+	dasd_enable_device(base);
 	/* Formatting the dasd device can change the capacity. */
 	mutex_lock(&bdev->bd_mutex);
-	i_size_write(bdev->bd_inode, (loff_t)get_capacity(block->gdp) << 9);
+	i_size_write(bdev->bd_inode,
+		     (loff_t)get_capacity(base->block->gdp) << 9);
 	mutex_unlock(&bdev->bd_mutex);
+	dasd_put_device(base);
 	return 0;
 }
 
@@ -62,11 +68,14 @@ dasd_ioctl_enable(struct block_device *bdev)
 static int
 dasd_ioctl_disable(struct block_device *bdev)
 {
-	struct dasd_block *block = bdev->bd_disk->private_data;
+	struct dasd_device *base;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EACCES;
 
+	base = dasd_device_from_gendisk(bdev->bd_disk);
+	if (!base)
+		return -ENODEV;
 	/*
 	 * Man this is sick. We don't do a real disable but only downgrade
 	 * the device to DASD_STATE_BASIC. The reason is that dasdfmt uses
@@ -75,7 +84,7 @@ dasd_ioctl_disable(struct block_device *bdev)
 	 * using the BIODASDFMT ioctl. Therefore the correct state for the
 	 * device is DASD_STATE_BASIC that allows to do basic i/o.
 	 */
-	dasd_set_target_state(block->base, DASD_STATE_BASIC);
+	dasd_set_target_state(base, DASD_STATE_BASIC);
 	/*
 	 * Set i_size to zero, since read, write, etc. check against this
 	 * value.
@@ -83,6 +92,7 @@ dasd_ioctl_disable(struct block_device *bdev)
 	mutex_lock(&bdev->bd_mutex);
 	i_size_write(bdev->bd_inode, 0);
 	mutex_unlock(&bdev->bd_mutex);
+	dasd_put_device(base);
 	return 0;
 }
 
@@ -191,26 +201,36 @@ static int dasd_format(struct dasd_block *block, struct format_data_t *fdata)
 static int
 dasd_ioctl_format(struct block_device *bdev, void __user *argp)
 {
-	struct dasd_block *block = bdev->bd_disk->private_data;
+	struct dasd_device *base;
 	struct format_data_t fdata;
+	int rc;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EACCES;
 	if (!argp)
 		return -EINVAL;
-
-	if (block->base->features & DASD_FEATURE_READONLY ||
-	    test_bit(DASD_FLAG_DEVICE_RO, &block->base->flags))
+	base = dasd_device_from_gendisk(bdev->bd_disk);
+	if (!base)
+		return -ENODEV;
+	if (base->features & DASD_FEATURE_READONLY ||
+	    test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
+		dasd_put_device(base);
 		return -EROFS;
-	if (copy_from_user(&fdata, argp, sizeof(struct format_data_t)))
+	}
+	if (copy_from_user(&fdata, argp, sizeof(struct format_data_t))) {
+		dasd_put_device(base);
 		return -EFAULT;
+	}
 	if (bdev != bdev->bd_contains) {
 		pr_warning("%s: The specified DASD is a partition and cannot "
 			   "be formatted\n",
-			   dev_name(&block->base->cdev->dev));
+			   dev_name(&base->cdev->dev));
+		dasd_put_device(base);
 		return -EINVAL;
 	}
-	return dasd_format(block, &fdata);
+	rc = dasd_format(base->block, &fdata);
+	dasd_put_device(base);
+	return rc;
 }
 
 #ifdef CONFIG_DASD_PROFILE
@@ -340,8 +360,8 @@ static int dasd_ioctl_information(struct dasd_block *block,
 static int
 dasd_ioctl_set_ro(struct block_device *bdev, void __user *argp)
 {
-	struct dasd_block *block =  bdev->bd_disk->private_data;
-	int intval;
+	struct dasd_device *base;
+	int intval, rc;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EACCES;
@@ -350,10 +370,17 @@ dasd_ioctl_set_ro(struct block_device *bdev, void __user *argp)
 		return -EINVAL;
 	if (get_user(intval, (int __user *)argp))
 		return -EFAULT;
-	if (!intval && test_bit(DASD_FLAG_DEVICE_RO, &block->base->flags))
+	base = dasd_device_from_gendisk(bdev->bd_disk);
+	if (!base)
+		return -ENODEV;
+	if (!intval && test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
+		dasd_put_device(base);
 		return -EROFS;
+	}
 	set_disk_ro(bdev->bd_disk, intval);
-	return dasd_set_feature(block->base->cdev, DASD_FEATURE_READONLY, intval);
+	rc = dasd_set_feature(base->cdev, DASD_FEATURE_READONLY, intval);
+	dasd_put_device(base);
+	return rc;
 }
 
 static int dasd_ioctl_readall_cmb(struct dasd_block *block, unsigned int cmd,
@@ -372,59 +399,78 @@ static int dasd_ioctl_readall_cmb(struct dasd_block *block, unsigned int cmd,
 int dasd_ioctl(struct block_device *bdev, fmode_t mode,
 	       unsigned int cmd, unsigned long arg)
 {
-	struct dasd_block *block = bdev->bd_disk->private_data;
+	struct dasd_block *block;
+	struct dasd_device *base;
 	void __user *argp;
+	int rc;
 
 	if (is_compat_task())
 		argp = compat_ptr(arg);
 	else
 		argp = (void __user *)arg;
 
-	if (!block)
-                return -ENODEV;
-
 	if ((_IOC_DIR(cmd) != _IOC_NONE) && !arg) {
 		PRINT_DEBUG("empty data ptr");
 		return -EINVAL;
 	}
 
+	base = dasd_device_from_gendisk(bdev->bd_disk);
+	if (!base)
+		return -ENODEV;
+	block = base->block;
+	rc = 0;
 	switch (cmd) {
 	case BIODASDDISABLE:
-		return dasd_ioctl_disable(bdev);
+		rc = dasd_ioctl_disable(bdev);
+		break;
 	case BIODASDENABLE:
-		return dasd_ioctl_enable(bdev);
+		rc = dasd_ioctl_enable(bdev);
+		break;
 	case BIODASDQUIESCE:
-		return dasd_ioctl_quiesce(block);
+		rc = dasd_ioctl_quiesce(block);
+		break;
 	case BIODASDRESUME:
-		return dasd_ioctl_resume(block);
+		rc = dasd_ioctl_resume(block);
+		break;
 	case BIODASDFMT:
-		return dasd_ioctl_format(bdev, argp);
+		rc = dasd_ioctl_format(bdev, argp);
+		break;
 	case BIODASDINFO:
-		return dasd_ioctl_information(block, cmd, argp);
+		rc = dasd_ioctl_information(block, cmd, argp);
+		break;
 	case BIODASDINFO2:
-		return dasd_ioctl_information(block, cmd, argp);
+		rc = dasd_ioctl_information(block, cmd, argp);
+		break;
 	case BIODASDPRRD:
-		return dasd_ioctl_read_profile(block, argp);
+		rc = dasd_ioctl_read_profile(block, argp);
+		break;
 	case BIODASDPRRST:
-		return dasd_ioctl_reset_profile(block);
+		rc = dasd_ioctl_reset_profile(block);
+		break;
 	case BLKROSET:
-		return dasd_ioctl_set_ro(bdev, argp);
+		rc = dasd_ioctl_set_ro(bdev, argp);
+		break;
 	case DASDAPIVER:
-		return dasd_ioctl_api_version(argp);
+		rc = dasd_ioctl_api_version(argp);
+		break;
 	case BIODASDCMFENABLE:
-		return enable_cmf(block->base->cdev);
+		rc = enable_cmf(base->cdev);
+		break;
 	case BIODASDCMFDISABLE:
-		return disable_cmf(block->base->cdev);
+		rc = disable_cmf(base->cdev);
+		break;
 	case BIODASDREADALLCMB:
-		return dasd_ioctl_readall_cmb(block, cmd, argp);
+		rc = dasd_ioctl_readall_cmb(block, cmd, argp);
+		break;
 	default:
 		/* if the discipline has an ioctl method try it. */
-		if (block->base->discipline->ioctl) {
-			int rval = block->base->discipline->ioctl(block, cmd, argp);
-			if (rval != -ENOIOCTLCMD)
-				return rval;
-		}
-
-		return -EINVAL;
+		if (base->discipline->ioctl) {
+			rc = base->discipline->ioctl(block, cmd, argp);
+			if (rc == -ENOIOCTLCMD)
+				rc = -EINVAL;
+		} else
+			rc = -EINVAL;
 	}
+	dasd_put_device(base);
+	return rc;
 }
diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c
index 4b60ede07f0e..be55fb2b1b1c 100644
--- a/drivers/s390/char/sclp_cmd.c
+++ b/drivers/s390/char/sclp_cmd.c
@@ -518,6 +518,8 @@ static void __init insert_increment(u16 rn, int standby, int assigned)
 		return;
 	new_incr->rn = rn;
 	new_incr->standby = standby;
+	if (!standby)
+		new_incr->usecount = 1;
 	last_rn = 0;
 	prev = &sclp_mem_list;
 	list_for_each_entry(incr, &sclp_mem_list, list) {
diff --git a/drivers/s390/char/tape_block.c b/drivers/s390/char/tape_block.c
index 83cea9a55e2f..1b3924c2fffd 100644
--- a/drivers/s390/char/tape_block.c
+++ b/drivers/s390/char/tape_block.c
@@ -236,7 +236,6 @@ tapeblock_setup_device(struct tape_device * device)
 	disk->major = tapeblock_major;
 	disk->first_minor = device->first_minor;
 	disk->fops = &tapeblock_fops;
-	disk->events = DISK_EVENT_MEDIA_CHANGE;
 	disk->private_data = tape_get_device(device);
 	disk->queue = blkdat->request_queue;
 	set_capacity(disk, 0);
diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index c532ba929ccd..e8f267eb8887 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -407,8 +407,11 @@ static inline void account_sbals(struct qdio_q *q, int count)
 	q->q_stats.nr_sbals[pos]++;
 }
 
-static void announce_buffer_error(struct qdio_q *q, int count)
+static void process_buffer_error(struct qdio_q *q, int count)
 {
+	unsigned char state = (q->is_input_q) ? SLSB_P_INPUT_NOT_INIT :
+					SLSB_P_OUTPUT_NOT_INIT;
+
 	q->qdio_error |= QDIO_ERROR_SLSB_STATE;
 
 	/* special handling for no target buffer empty */
@@ -426,6 +429,12 @@ static void announce_buffer_error(struct qdio_q *q, int count)
 	DBF_ERROR("F14:%2x F15:%2x",
 		  q->sbal[q->first_to_check]->element[14].flags & 0xff,
 		  q->sbal[q->first_to_check]->element[15].flags & 0xff);
+
+	/*
+	 * Interrupts may be avoided as long as the error is present
+	 * so change the buffer state immediately to avoid starvation.
+	 */
+	set_buf_states(q, q->first_to_check, state, count);
 }
 
 static inline void inbound_primed(struct qdio_q *q, int count)
@@ -506,8 +515,7 @@ static int get_inbound_buffer_frontier(struct qdio_q *q)
 			account_sbals(q, count);
 		break;
 	case SLSB_P_INPUT_ERROR:
-		announce_buffer_error(q, count);
-		/* process the buffer, the upper layer will take care of it */
+		process_buffer_error(q, count);
 		q->first_to_check = add_buf(q->first_to_check, count);
 		atomic_sub(count, &q->nr_buf_used);
 		if (q->irq_ptr->perf_stat_enabled)
@@ -677,8 +685,7 @@ static int get_outbound_buffer_frontier(struct qdio_q *q)
 			account_sbals(q, count);
 		break;
 	case SLSB_P_OUTPUT_ERROR:
-		announce_buffer_error(q, count);
-		/* process the buffer, the upper layer will take care of it */
+		process_buffer_error(q, count);
 		q->first_to_check = add_buf(q->first_to_check, count);
 		atomic_sub(count, &q->nr_buf_used);
 		if (q->irq_ptr->perf_stat_enabled)
diff --git a/drivers/s390/kvm/kvm_virtio.c b/drivers/s390/kvm/kvm_virtio.c
index 414427d64a8f..607998f0b7d8 100644
--- a/drivers/s390/kvm/kvm_virtio.c
+++ b/drivers/s390/kvm/kvm_virtio.c
@@ -381,10 +381,10 @@ static void kvm_extint_handler(unsigned int ext_int_code,
 	u16 subcode;
 	u32 param;
 
-	kstat_cpu(smp_processor_id()).irqs[EXTINT_VRT]++;
 	subcode = ext_int_code >> 16;
 	if ((subcode & 0xff00) != VIRTIO_SUBCODE_64)
 		return;
+	kstat_cpu(smp_processor_id()).irqs[EXTINT_VRT]++;
 
 	/* The LSB might be overloaded, we have to mask it */
 	vq = (struct virtqueue *)(param64 & ~1UL);