s390/dasd: Add dynamic formatting support for ESE volumes

A dynamic formatting is issued whenever a write request returns with
either a No Record Found error (Command Mode), Incorrect Length error
(Transport Mode), or File Protected error (Transport Mode). All three
cases mean that the tracks in question haven't been initialized in a
desired format yet.

The part of the volume that was tried to be written on is then formatted
and the original request is re-queued.

As the formatting will happen during normal I/O operations, it is quite
likely that there won't be any memory available to build the respective
request. Another two pages of memory are allocated per volume
specifically for the dynamic formatting.

The dasd_eckd_build_format() function is extended to make sure that the
original startdev is reused. Also, all formatting and format check
functions use the new memory pool exclusively now to reduce complexity.

Read operations will always return zero data when unformatted areas are
read.

Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

1 files changed, 112 insertions, 1 deletions

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index e03304fe25bb..1c7da4342461 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -120,9 +120,18 @@ struct dasd_device *dasd_alloc_device(void)
 		kfree(device);
 		return ERR_PTR(-ENOMEM);
 	}
+	/* Get two pages for ese format. */
+	device->ese_mem = (void *)__get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
+	if (!device->ese_mem) {
+		free_page((unsigned long) device->erp_mem);
+		free_pages((unsigned long) device->ccw_mem, 1);
+		kfree(device);
+		return ERR_PTR(-ENOMEM);
+	}
 
 	dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 	dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
+	dasd_init_chunklist(&device->ese_chunks, device->ese_mem, PAGE_SIZE * 2);
 	spin_lock_init(&device->mem_lock);
 	atomic_set(&device->tasklet_scheduled, 0);
 	tasklet_init(&device->tasklet, dasd_device_tasklet,
@@ -146,6 +155,7 @@ struct dasd_device *dasd_alloc_device(void)
 void dasd_free_device(struct dasd_device *device)
 {
 	kfree(device->private);
+	free_pages((unsigned long) device->ese_mem, 1);
 	free_page((unsigned long) device->erp_mem);
 	free_pages((unsigned long) device->ccw_mem, 1);
 	kfree(device);
@@ -1258,6 +1268,49 @@ struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength, int datasize,
 }
 EXPORT_SYMBOL(dasd_smalloc_request);
 
+struct dasd_ccw_req *dasd_fmalloc_request(int magic, int cplength,
+					  int datasize,
+					  struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr;
+	unsigned long flags;
+	int size, cqr_size;
+	char *data;
+
+	cqr_size = (sizeof(*cqr) + 7L) & -8L;
+	size = cqr_size;
+	if (cplength > 0)
+		size += cplength * sizeof(struct ccw1);
+	if (datasize > 0)
+		size += datasize;
+
+	spin_lock_irqsave(&device->mem_lock, flags);
+	cqr = dasd_alloc_chunk(&device->ese_chunks, size);
+	spin_unlock_irqrestore(&device->mem_lock, flags);
+	if (!cqr)
+		return ERR_PTR(-ENOMEM);
+	memset(cqr, 0, sizeof(*cqr));
+	data = (char *)cqr + cqr_size;
+	cqr->cpaddr = NULL;
+	if (cplength > 0) {
+		cqr->cpaddr = data;
+		data += cplength * sizeof(struct ccw1);
+		memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
+	}
+	cqr->data = NULL;
+	if (datasize > 0) {
+		cqr->data = data;
+		memset(cqr->data, 0, datasize);
+	}
+
+	cqr->magic = magic;
+	set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+	dasd_get_device(device);
+
+	return cqr;
+}
+EXPORT_SYMBOL(dasd_fmalloc_request);
+
 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
 {
 	unsigned long flags;
@@ -1269,6 +1322,17 @@ void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
 }
 EXPORT_SYMBOL(dasd_sfree_request);
 
+void dasd_ffree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&device->mem_lock, flags);
+	dasd_free_chunk(&device->ese_chunks, cqr);
+	spin_unlock_irqrestore(&device->mem_lock, flags);
+	dasd_put_device(device);
+}
+EXPORT_SYMBOL(dasd_ffree_request);
+
 /*
  * Check discipline magic in cqr.
  */
@@ -1573,13 +1637,35 @@ static int dasd_check_hpf_error(struct irb *irb)
 	     irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX));
 }
 
+static int dasd_ese_needs_format(struct dasd_block *block, struct irb *irb)
+{
+	struct dasd_device *device = NULL;
+	u8 *sense = NULL;
+
+	if (!block)
+		return 0;
+	device = block->base;
+	if (!device || !device->discipline->is_ese)
+		return 0;
+	if (!device->discipline->is_ese(device))
+		return 0;
+
+	sense = dasd_get_sense(irb);
+	if (!sense)
+		return 0;
+
+	return !!(sense[1] & SNS1_NO_REC_FOUND) ||
+		!!(sense[1] & SNS1_FILE_PROTECTED) ||
+		scsw_cstat(&irb->scsw) == SCHN_STAT_INCORR_LEN;
+}
+
 /*
  * Interrupt handler for "normal" ssch-io based dasd devices.
  */
 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
 		      struct irb *irb)
 {
-	struct dasd_ccw_req *cqr, *next;
+	struct dasd_ccw_req *cqr, *next, *fcqr;
 	struct dasd_device *device;
 	unsigned long now;
 	int nrf_suppressed = 0;
@@ -1672,6 +1758,31 @@ void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
 		return;
 	}
 
+	if (dasd_ese_needs_format(cqr->block, irb)) {
+		if (rq_data_dir((struct request *)cqr->callback_data) == READ) {
+			device->discipline->ese_read(cqr);
+			cqr->status = DASD_CQR_SUCCESS;
+			cqr->stopclk = now;
+			dasd_device_clear_timer(device);
+			dasd_schedule_device_bh(device);
+			return;
+		}
+		fcqr = device->discipline->ese_format(device, cqr);
+		if (IS_ERR(fcqr)) {
+			/*
+			 * If we can't format now, let the request go
+			 * one extra round. Maybe we can format later.
+			 */
+			cqr->status = DASD_CQR_QUEUED;
+		} else {
+			fcqr->status = DASD_CQR_QUEUED;
+			cqr->status = DASD_CQR_QUEUED;
+			list_add(&fcqr->devlist, &device->ccw_queue);
+			dasd_schedule_device_bh(device);
+			return;
+		}
+	}
+
 	/* Check for clear pending */
 	if (cqr->status == DASD_CQR_CLEAR_PENDING &&
 	    scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {