IDE: Fix HDIO_DRIVE_RESET handling
Currently, the code path executing an HDIO_DRIVE_RESET ioctl is broken
in various ways. Most importantly, it is treated as an out of band
request in an illegal way which may very likely lead to system lock ups.
Use the drive's request queue to avoid this problem (and fix a locking
issue for free along the way).
Signed-off-by: Elias Oltmanns <eo@nebensachen.de>
Cc: "Alan Cox" <alan@lxorguk.ukuu.org.uk>
Cc: "Randy Dunlap" <randy.dunlap@oracle.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 2805774..2b33c12 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -766,6 +766,18 @@
return ide_stopped;
}
+static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq)
+{
+ switch (rq->cmd[0]) {
+ case REQ_DRIVE_RESET:
+ return ide_do_reset(drive);
+ default:
+ blk_dump_rq_flags(rq, "ide_special_rq - bad request");
+ ide_end_request(drive, 0, 0);
+ return ide_stopped;
+ }
+}
+
static void ide_check_pm_state(ide_drive_t *drive, struct request *rq)
{
struct request_pm_state *pm = rq->data;
@@ -869,7 +881,16 @@
pm->pm_step == ide_pm_state_completed)
ide_complete_pm_request(drive, rq);
return startstop;
- }
+ } else if (!rq->rq_disk && blk_special_request(rq))
+ /*
+ * TODO: Once all ULDs have been modified to
+ * check for specific op codes rather than
+ * blindly accepting any special request, the
+ * check for ->rq_disk above may be replaced
+ * by a more suitable mechanism or even
+ * dropped entirely.
+ */
+ return ide_special_rq(drive, rq);
drv = *(ide_driver_t **)rq->rq_disk->private_data;
return drv->do_request(drive, rq, block);
diff --git a/drivers/ide/ide-iops.c b/drivers/ide/ide-iops.c
index 80ad4f2..96f63eb 100644
--- a/drivers/ide/ide-iops.c
+++ b/drivers/ide/ide-iops.c
@@ -905,6 +905,14 @@
}
EXPORT_SYMBOL_GPL(ide_execute_pkt_cmd);
+static inline void ide_complete_drive_reset(ide_drive_t *drive)
+{
+ struct request *rq = drive->hwif->hwgroup->rq;
+
+ if (rq && blk_special_request(rq) && rq->cmd[0] == REQ_DRIVE_RESET)
+ ide_end_request(drive, 1, 0);
+}
+
/* needed below */
static ide_startstop_t do_reset1 (ide_drive_t *, int);
@@ -940,7 +948,7 @@
}
/* done polling */
hwgroup->polling = 0;
- hwgroup->resetting = 0;
+ ide_complete_drive_reset(drive);
return ide_stopped;
}
@@ -961,7 +969,7 @@
if (port_ops->reset_poll(drive)) {
printk(KERN_ERR "%s: host reset_poll failure for %s.\n",
hwif->name, drive->name);
- return ide_stopped;
+ goto out;
}
}
@@ -1004,7 +1012,8 @@
}
}
hwgroup->polling = 0; /* done polling */
- hwgroup->resetting = 0; /* done reset attempt */
+out:
+ ide_complete_drive_reset(drive);
return ide_stopped;
}
@@ -1090,7 +1099,6 @@
/* For an ATAPI device, first try an ATAPI SRST. */
if (drive->media != ide_disk && !do_not_try_atapi) {
- hwgroup->resetting = 1;
pre_reset(drive);
SELECT_DRIVE(drive);
udelay (20);
@@ -1112,10 +1120,10 @@
if (io_ports->ctl_addr == 0) {
spin_unlock_irqrestore(&ide_lock, flags);
+ ide_complete_drive_reset(drive);
return ide_stopped;
}
- hwgroup->resetting = 1;
/*
* Note that we also set nIEN while resetting the device,
* to mask unwanted interrupts from the interface during the reset.
diff --git a/drivers/ide/ide.c b/drivers/ide/ide.c
index 90ae00d..1ec983b 100644
--- a/drivers/ide/ide.c
+++ b/drivers/ide/ide.c
@@ -529,6 +529,19 @@
return err;
}
+static void generic_drive_reset(ide_drive_t *drive)
+{
+ struct request *rq;
+
+ rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
+ rq->cmd_type = REQ_TYPE_SPECIAL;
+ rq->cmd_len = 1;
+ rq->cmd[0] = REQ_DRIVE_RESET;
+ rq->cmd_flags |= REQ_SOFTBARRIER;
+ blk_execute_rq(drive->queue, NULL, rq, 1);
+ blk_put_request(rq);
+}
+
int generic_ide_ioctl(ide_drive_t *drive, struct file *file, struct block_device *bdev,
unsigned int cmd, unsigned long arg)
{
@@ -603,33 +616,9 @@
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
- /*
- * Abort the current command on the
- * group if there is one, taking
- * care not to allow anything else
- * to be queued and to die on the
- * spot if we miss one somehow
- */
-
- spin_lock_irqsave(&ide_lock, flags);
-
- if (HWGROUP(drive)->resetting) {
- spin_unlock_irqrestore(&ide_lock, flags);
- return -EBUSY;
- }
-
- ide_abort(drive, "drive reset");
-
- BUG_ON(HWGROUP(drive)->handler);
-
- /* Ensure nothing gets queued after we
- drop the lock. Reset will clear the busy */
-
- HWGROUP(drive)->busy = 1;
- spin_unlock_irqrestore(&ide_lock, flags);
- (void) ide_do_reset(drive);
-
+ generic_drive_reset(drive);
return 0;
+
case HDIO_GET_BUSSTATE:
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
diff --git a/include/linux/ide.h b/include/linux/ide.h
index f9cbe93..021710c 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -139,6 +139,12 @@
#define WAIT_MIN_SLEEP (2*HZ/100) /* 20msec - minimum sleep time */
/*
+ * Op codes for special requests to be handled by ide_special_rq().
+ * Values should be in the range of 0x20 to 0x3f.
+ */
+#define REQ_DRIVE_RESET 0x20
+
+/*
* Check for an interrupt and acknowledge the interrupt status
*/
struct hwif_s;