[PATCH 9/9] dasd: Fail all requests when DASD_FLAG_ABORTIO is set

Martin Schwidefsky
2013-06-03T15:03:22Z

Whenever a DASD request encounters a timeout we might
need to abort all outstanding requests on this or
even other devices.

This is especially useful if one wants to fail all
devices on one side of a RAID10 configuration, even
though only one device exhibited an error.

To handle this I've introduced a new device flag
DASD_FLAG_ABORTIO.
This flag is evaluated in __dasd_process_request_queue()
and will invoke blk_abort_request() for all
outstanding requests with DASD_CQR_FLAGS_FAILFAST set.
This will cause any of these requests to be aborted
immediately if the blk_timeout function is activated.

The DASD_FLAG_ABORTIO is also evaluated in
__dasd_process_request_queue to abort all
new request which would have the
DASD_CQR_FLAGS_FAILFAST bit set.

The flag can be set with the new ioctls 'BIODASDABORTIO'
and removed with 'BIODASDALLOWIO'.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
arch/s390/include/uapi/asm/dasd.h | 4 +++
drivers/s390/block/dasd.c | 13 ++++++--
drivers/s390/block/dasd_int.h | 3 ++
drivers/s390/block/dasd_ioctl.c | 59 +++++++++++++++++++++++++++++++++++++
4 files changed, 76 insertions(+), 3 deletions(-)

diff --git a/arch/s390/include/uapi/asm/dasd.h b/arch/s390/include/uapi/asm/dasd.h
index 38eca3b..5812a3b 100644
--- a/arch/s390/include/uapi/asm/dasd.h
+++ b/arch/s390/include/uapi/asm/dasd.h
@@ -261,6 +261,10 @@ struct dasd_snid_ioctl_data {
#define BIODASDQUIESCE _IO(DASD_IOCTL_LETTER,6)
/* Resume IO on device */
#define BIODASDRESUME _IO(DASD_IOCTL_LETTER,7)
+/* Abort all I/O on a device */
+#define BIODASDABORTIO _IO(DASD_IOCTL_LETTER, 240)
+/* Allow I/O on a device */
+#define BIODASDALLOWIO _IO(DASD_IOCTL_LETTER, 241)

/* retrieve API version number */
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 54f4bb8..17150a7 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -38,9 +38,6 @@
*/
#define DASD_CHANQ_MAX_SIZE 4

-#define DASD_SLEEPON_START_TAG (void *) 1
-#define DASD_SLEEPON_END_TAG (void *) 2
-
/*
* SECTION: exported variables of dasd.c
*/
@@ -2535,6 +2532,16 @@ static void __dasd_process_request_queue(struct dasd_block *block)
__blk_end_request_all(req, -EIO);
continue;
}
+ if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
+ (basedev->features & DASD_FEATURE_FAILFAST ||
+ blk_noretry_request(req))) {
+ DBF_DEV_EVENT(DBF_ERR, basedev,
+ "Rejecting failfast request %p",
+ req);
+ blk_start_request(req);
+ __blk_end_request_all(req, -ETIMEDOUT);
+ continue;
+ }
cqr = basedev->discipline->build_cp(basedev, block, req);
if (IS_ERR(cqr)) {
if (PTR_ERR(cqr) == -EBUSY)
diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index 2bd03f4..690001a 100644
--- a/drivers/s390/block/dasd_int.h
+++ b/drivers/s390/block/dasd_int.h
@@ -524,7 +524,10 @@ struct dasd_block {
#define DASD_FLAG_SUSPENDED 9 /* The device was suspended */
#define DASD_FLAG_SAFE_OFFLINE 10 /* safe offline processing requested*/
#define DASD_FLAG_SAFE_OFFLINE_RUNNING 11 /* safe offline running */
+#define DASD_FLAG_ABORTALL 12 /* Abort all noretry requests */

+#define DASD_SLEEPON_START_TAG ((void *) 1)
+#define DASD_SLEEPON_END_TAG ((void *) 2)

void dasd_put_device_wake(struct dasd_device *);

diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
index 8be1b51..25a0f2f 100644
--- a/drivers/s390/block/dasd_ioctl.c
+++ b/drivers/s390/block/dasd_ioctl.c
@@ -141,6 +141,59 @@ static int dasd_ioctl_resume(struct dasd_block *block)
}

/*
+ * Abort all failfast I/O on a device.
+ */
+static int dasd_ioctl_abortio(struct dasd_block *block)
+{
+ unsigned long flags;
+ struct dasd_device *base;
+ struct dasd_ccw_req *cqr, *n;
+
+ base = block->base;
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ if (test_and_set_bit(DASD_FLAG_ABORTALL, &base->flags))
+ return 0;
+ DBF_DEV_EVENT(DBF_NOTICE, base, "%s", "abortall flag set");
+
+ spin_lock_irqsave(&block->request_queue_lock, flags);
+ spin_lock(&block->queue_lock);
+ list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
+ if (test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
+ cqr->callback_data &&
+ cqr->callback_data != DASD_SLEEPON_START_TAG &&
+ cqr->callback_data != DASD_SLEEPON_END_TAG) {
+ spin_unlock(&block->queue_lock);
+ blk_abort_request(cqr->callback_data);
+ spin_lock(&block->queue_lock);
+ }
+ }
+ spin_unlock(&block->queue_lock);
+ spin_unlock_irqrestore(&block->request_queue_lock, flags);
+
+ dasd_schedule_block_bh(block);
+ return 0;
+}
+
+/*
+ * Allow I/O on a device
+ */
+static int dasd_ioctl_allowio(struct dasd_block *block)
+{
+ struct dasd_device *base;
+
+ base = block->base;
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ if (test_and_clear_bit(DASD_FLAG_ABORTALL, &base->flags))
+ DBF_DEV_EVENT(DBF_NOTICE, base, "%s", "abortall flag unset");
+
+ return 0;
+}
+
+/*
* performs formatting of _device_ according to _fdata_
* Note: The discipline's format_function is assumed to deliver formatting
* commands to format multiple units of the device. In terms of the ECKD
@@ -458,6 +511,12 @@ int dasd_ioctl(struct block_device *bdev, fmode_t mode,
case BIODASDRESUME:
rc = dasd_ioctl_resume(block);
break;
+ case BIODASDABORTIO:
+ rc = dasd_ioctl_abortio(block);
+ break;
+ case BIODASDALLOWIO:
+ rc = dasd_ioctl_allowio(block);
+ break;
case BIODASDFMT:
rc = dasd_ioctl_format(bdev, argp);
break;
--
1.7.9.5