Re: is there any Hard-disk shock-protection for 2.6.18 and above?

Elias Oltmanns
2006-12-10T01:03:37Z

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Hi Pavel,

Pavel Machek <pavel@ucw.cz> wrote:
>> >> +module_param_named(protect_method, libata_protect_method, int, 0444);
>> >> +MODULE_PARM_DESC(protect_method, "hdaps disk protection method (0=autodetect, 1=unload, 2=standby)");
>> >
>> > Should this be configurable by module parameter? Why not tell each
>> > unload what to do?
[...]
>> > Is /sys interface right thing to do?
>>
>> Probably, you're right here. Since this feature is actually drive
>> specific, it should not really be set globally as a libata or ide-disk
>> parameter but specifically for each drive connected. Perhaps we should
>> add another attribute to /sys/block/*/queue or enhance the scope of
>> /sys/block/*/queue/protect?
>
> Certainly better than current solution. Or maybe ioctl similar to wat
> hdparm uses?
> Pavel

I'm not quite sure what you have in mind wrt ioctls. I'm still
convinced that the administrator should take a conscious decision when
forcing an idle immediate with unload feature on a drive which doesn't
announce this capability according to the specs. This is because I
have no idea as to how drives might react if they don't support it.
Perhaps we should consult linux-ide on this topic.

Anyway, this is the reason why I favour the sysfs approach. The
decision can be made, for instance, in a udev rule during device
setup.

So, here is a patch in which your remarks and suggestions have been
incorporated. Additionally, I've added the requested kernel doc file
and another sysfs attribute called protect_method. The usage of this
attribute is described in Documentation/block/disk-protection.txt.

Patch applies to 2.6.19.

Signed-off-by: Elias Oltmanns <eo@nebensachen.de>
---
Documentation/block/disk-protection.txt | 79 +++++++
block/ll_rw_blk.c | 224 ++++++++++++++++++++++
drivers/ata/libata-scsi.c | 29 ++
drivers/ide/ide-disk.c | 142 +++++++++++++
drivers/ide/ide-io.c | 14 +
drivers/scsi/scsi_lib.c | 163 ++++++++++++++++
include/linux/ata.h | 1
include/linux/blkdev.h | 14 +
include/linux/ide.h | 1
9 files changed, 667 insertions(+)

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diff --git a/Documentation/block/disk-protection.txt b/Documentation/block/disk-protection.txt
new file mode 100644
index 0000000..508cc5b
--- /dev/null
+++ b/Documentation/block/disk-protection.txt
@@ -0,0 +1,79 @@
+Hard disk protection
+====================
+
+
+Intro
+-----
+ATA/ATAPI-7 specifies the IDLE IMMEDIATE command with UNLOAD FEATURE.
+Issuing this command should cause the drive to switch to idle mode and
+unload disk heads. This feature is being used in modern laptops in
+conjunction with accelerometers and appropriate software to implement
+a shock protection facility. The idea is to stop all I/O operations on
+the internal hard drive and park its heads on the ramp when critical
+situations are anticipated. The desire to have such a feature
+available on GNU/Linux systems has been the original motivation to
+implement a generic disk parking interface in the Linux kernel.
+
+
+The interface
+-------------
+The interface works as follows: Writing an integer value to
+/sys/block/*/queue/protect will park the respective drive and freeze
+the block layer queue for the specified number of seconds. When the
+timeout expires and no further disk park request has been issued in
+the meantime, the queue is unfrozen and accumulated I/O operations are
+performed.
+
+IMPORTANT NOTE:
+Not all ATA drives implement IDLE IMMEDIATE with UNLOAD FEATURE and
+quite a few of those that do so, don't report this capability as
+described in the specs. When a disk park has been requested through
+sysfs as described above, the kernel will try to determine if the
+drive supports the UNLOAD FEATURE by default. The kernel will only
+rely on the IDLE IMMEDIATE with UNLOAD FEATURE command if it is
+convinced that this command is actually supported by the disk drive;
+otherwise, it will fall back to STANDBY IMMEDIATE. Resuming from the
+latter will take much longer and it is generally more likely to have a
+negative impact on the drive's lifetime due to the inclease of spin
+down and up cycles. If you want to use this interface in a shock
+protection framework and you know that your drive does indeed support
+the IDLE IMMEDIATE with UNLOAD FEATURE command despite not saying so,
+you can force the kernel to issue that command by doing the following
+on the command line:
+# echo -n unload > /sys/block/sda/queue/protect_method
+(replace sda by the drive identifier as appropriate).
+
+/sys/block/*/queue/protect_method accepts auto, unload and standby
+respectively. Reading from protect_method shows the available options
+surrounding the active one with brackets. When auto is active, this
+will change to whatever the kernel sees fit after the next disk park
+command has been issued.
+
+
+References
+----------
+
+There are several laptops from different brands featuring shock
+protection capabilities. As manufacturers have refused to support open
+source development of the required software components so far, Linux
+support for shock protection varies considerably between different
+hardware implementations. Ideally, this section should contain a list
+of poiters at different projects aiming at an implementation of shock
+protection on different systeems. Unfortunately, I only know of a
+single project which, although still considered experimental, is fit
+for use. Please feel free to add projects that have been the victims
+of my ignorance.
+
+- http://www.thinkwiki.org/wiki/HDAPS
+ See this page for information about Linux support of the hard disk
+ active protection syystem as implemented in IBM/Lenovo Thinkpads.
+
+
+CREDITS
+-------
+
+The patch to implement the interface described in this file has
+originally been published by Jon Escombe <lists@dresco.co.uk>.
+
+
+05 Dec 2006, Elias Oltmanns <eo@nebensachen.de>
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 9eaee66..a03ed2b 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -36,10 +36,14 @@ #include <scsi/scsi_cmnd.h>

static void blk_unplug_work(void *data);
static void blk_unplug_timeout(unsigned long data);
+static void blk_unfreeze_work(void *data);
+static void blk_unfreeze_timeout(unsigned long data);
static void drive_stat_acct(struct request *rq, int nr_sectors, int new_io);
static void init_request_from_bio(struct request *req, struct bio *bio);
static int __make_request(request_queue_t *q, struct bio *bio);
static struct io_context *current_io_context(gfp_t gfp_flags, int node);
+static int blk_protect_register(request_queue_t *q);
+static void blk_protect_unregister(request_queue_t *q);

/*
* For the allocated request tables
@@ -232,6 +236,16 @@ void blk_queue_make_request(request_queu
q->unplug_timer.function = blk_unplug_timeout;
q->unplug_timer.data = (unsigned long)q;

+ q->max_unfreeze = 30;
+
+ INIT_WORK(&q->unfreeze_work, blk_unfreeze_work, q);
+
+ q->unfreeze_timer.function = blk_unfreeze_timeout;
+ q->unfreeze_timer.data = (unsigned long)q;
+
+ /* Set protect_method to auto detection initially */
+ q->protect_method = 2;
+
/*
* by default assume old behaviour and bounce for any highmem page
*/
@@ -324,6 +338,18 @@ void blk_queue_issue_flush_fn(request_qu

EXPORT_SYMBOL(blk_queue_issue_flush_fn);

+void blk_queue_issue_protect_fn(request_queue_t *q, issue_protect_fn *ipf)
+{
+ q->issue_protect_fn = ipf;
+}
+EXPORT_SYMBOL(blk_queue_issue_protect_fn);
+
+void blk_queue_issue_unprotect_fn(request_queue_t *q, issue_unprotect_fn *iuf)
+{
+ q->issue_unprotect_fn = iuf;
+}
+EXPORT_SYMBOL(blk_queue_issue_unprotect_fn);
+
/*
* Cache flushing for ordered writes handling
*/
@@ -1842,6 +1868,7 @@ request_queue_t *blk_alloc_queue_node(gf

memset(q, 0, sizeof(*q));
init_timer(&q->unplug_timer);
+ init_timer(&q->unfreeze_timer);

snprintf(q->kobj.name, KOBJ_NAME_LEN, "%s", "queue");
q->kobj.ktype = &queue_ktype;
@@ -3917,6 +3944,7 @@ int blk_register_queue(struct gendisk *d
return ret;
}

+ blk_protect_register(q);
return 0;
}

@@ -3925,6 +3953,7 @@ void blk_unregister_queue(struct gendisk
request_queue_t *q = disk->queue;

if (q && q->request_fn) {
+ blk_protect_unregister(q);
elv_unregister_queue(q);

kobject_uevent(&q->kobj, KOBJ_REMOVE);
@@ -3932,3 +3961,198 @@ void blk_unregister_queue(struct gendisk
kobject_put(&disk->kobj);
}
}
+
+/*
+ * Issue lower level unprotect function if no timers are pending.
+ */
+static void blk_unfreeze_work(void *data)
+{
+ request_queue_t *q = (request_queue_t *) data;
+ int pending;
+ unsigned long flags;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ pending = timer_pending(&q->unfreeze_timer);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+ if (!pending)
+ q->issue_unprotect_fn(q);
+}
+
+/*
+ * Called when the queue freeze timeout expires...
+ */
+static void blk_unfreeze_timeout(unsigned long data)
+{
+ request_queue_t *q = (request_queue_t *) data;
+
+ kblockd_schedule_work(&q->unfreeze_work);
+}
+
+/*
+ * The lower level driver parks and freezes the queue, and this block layer
+ * function sets up the freeze timeout timer on return. If the queue is
+ * already frozen then this is called to extend the timer...
+ */
+void blk_freeze_queue(request_queue_t *q, int seconds)
+{
+ /* Don't accept arbitrarily long freezes */
+ if (seconds >= q->max_unfreeze)
+ seconds = q->max_unfreeze;
+ /* set/reset the timer */
+ mod_timer(&q->unfreeze_timer, msecs_to_jiffies(seconds*1000) + jiffies);
+}
+
+/*
+ * When reading the 'protect' attribute, we return seconds remaining
+ * before unfreeze timeout expires
+ */
+static ssize_t queue_protect_show(struct request_queue *q, char *page)
+{
+ unsigned int seconds = 0;
+
+ spin_lock_irq(q->queue_lock);
+ if (blk_queue_stopped(q) && timer_pending(&q->unfreeze_timer))
+ /*
+ * Adding 1 in order to guarantee nonzero value until timer
+ * has actually expired.
+ */
+ seconds = jiffies_to_msecs(q->unfreeze_timer.expires
+ - jiffies) / 1000 + 1;
+ spin_unlock_irq(q->queue_lock);
+ return queue_var_show(seconds, (page));
+}
+
+/*
+ * When writing the 'protect' attribute, input is the number of seconds
+ * to freeze the queue for. We call a lower level helper function to
+ * park the heads and freeze/block the queue, then we make a block layer
+ * call to setup the thaw timeout. If input is 0, then we thaw the queue.
+ */
+static ssize_t queue_protect_store(struct request_queue *q,
+ const char *page, size_t count)
+{
+ unsigned long freeze = 0;
+
+ queue_var_store(&freeze, page, count);
+
+ if (freeze>0) {
+ /* Park and freeze */
+ if (!blk_queue_stopped(q))
+ q->issue_protect_fn(q);
+ /* set / reset the thaw timer */
+ spin_lock_irq(q->queue_lock);
+ blk_freeze_queue(q, freeze);
+ spin_unlock_irq(q->queue_lock);
+ } else {
+ spin_lock_irq(q->queue_lock);
+ freeze = del_timer(&q->unfreeze_timer);
+ spin_unlock_irq(q->queue_lock);
+ if (freeze)
+ q->issue_unprotect_fn(q);
+ }
+
+ return count;
+}
+
+static ssize_t
+queue_str_show(char *page, char *str, int status)
+{
+ ssize_t len;
+
+ if (status & 1)
+ len = sprintf(page, "[%s]", str);
+ else
+ len = sprintf(page, "%s", str);
+ if (status & 2)
+ len += sprintf(page+len, "\n");
+ else
+ len += sprintf(page+len, " ");
+ return len;
+}
+
+/*
+ * Returns current protect_method.
+ */
+static ssize_t queue_protect_method_show(struct request_queue *q, char *page)
+{
+ int len = 0;
+ int unload = q->protect_method;
+
+ len += queue_str_show(page+len, "auto", (unload & 2) >> 1);
+ len += queue_str_show(page+len, "unload", unload & 1);
+ len += queue_str_show(page+len, "standby", !unload ? 3 : 2);
+ return len;
+}
+
+/*
+ * Stores the device protect method.
+ */
+static ssize_t queue_protect_method_store(struct request_queue *q,
+ const char *page, size_t count)
+{
+ spin_lock_irq(q->queue_lock);
+ if (!strcmp(page, "auto") || !strcmp(page, "auto\n"))
+ q->protect_method = 2;
+ else if (!strcmp(page, "unload") || !strcmp(page, "unload\n"))
+ q->protect_method = 1;
+ else if (!strcmp(page, "standby") || !strcmp(page, "standby\n"))
+ q->protect_method = 0;
+ else {
+ spin_unlock_irq(q->queue_lock);
+ return -EINVAL;
+ }
+ spin_unlock_irq(q->queue_lock);
+ return count;
+}
+
+static struct queue_sysfs_entry queue_protect_entry = {
+ .attr = { .name = "protect", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_protect_show,
+ .store = queue_protect_store,
+};
+static struct queue_sysfs_entry queue_protect_method_entry = {
+ .attr = { .name = "protect_method", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_protect_method_show,
+ .store = queue_protect_method_store,
+};
+
+static int blk_protect_register(request_queue_t *q)
+{
+ int error = 0;
+
+ /* check that the lower level driver has a protect handler */
+ if (!q->issue_protect_fn)
+ return 1;
+
+ /* create the attributes */
+ error = sysfs_create_file(&q->kobj, &queue_protect_entry.attr);
+ if (error) {
+ printk(KERN_ERR
+ "blk_protect_register(): failed to create protect queue attribute!\n");
+ return error;
+ }
+ kobject_get(&q->kobj);
+
+ error = sysfs_create_file(&q->kobj, &queue_protect_method_entry.attr);
+ if (error) {
+ printk(KERN_ERR
+ "blk_protect_register(): failed to create protect_method attribute!\n");
+ return error;
+ }
+ kobject_get(&q->kobj);
+
+ return 0;
+}
+
+static void blk_protect_unregister(request_queue_t *q)
+{
+ /* check that the lower level driver has a protect handler */
+ if (!q->issue_protect_fn)
+ return;
+
+ /* remove the attributes */
+ sysfs_remove_file(&q->kobj, &queue_protect_method_entry.attr);
+ kobject_put(&q->kobj);
+ sysfs_remove_file(&q->kobj, &queue_protect_entry.attr);
+ kobject_put(&q->kobj);
+}
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 47ea111..4dd00ca 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -841,6 +841,33 @@ static void ata_scsi_dev_config(struct s
}
}

+extern int scsi_protect_queue(request_queue_t *q, int unload);
+extern int scsi_unprotect_queue(request_queue_t *q);
+
+static int ata_scsi_issue_protect_fn(request_queue_t *q)
+{
+ struct scsi_device *sdev = q->queuedata;
+ struct ata_port *ap = (struct ata_port *) &sdev->host->hostdata[0];
+ struct ata_device *dev = &ap->device[sdev->id];
+ int unload = q->protect_method;
+ unsigned long flags;
+
+ if (unload == 2) {
+ unload = ata_id_has_unload(dev->id) ? 1 : 0;
+ spin_lock_irqsave(q->queue_lock, flags);
+ q->protect_method = unload;
+ spin_unlock_irqrestore(q->queue_lock, flags);
+ }
+
+ /* call scsi_protect_queue, requesting either unload or standby */
+ return scsi_protect_queue(q, unload);
+}
+
+static int ata_scsi_issue_unprotect_fn(request_queue_t *q)
+{
+ return scsi_unprotect_queue(q);
+}
+
/**
* ata_scsi_slave_config - Set SCSI device attributes
* @sdev: SCSI device to examine
@@ -864,6 +891,8 @@ int ata_scsi_slave_config(struct scsi_de

if (dev)
ata_scsi_dev_config(sdev, dev);
+ blk_queue_issue_protect_fn(sdev->request_queue, ata_scsi_issue_protect_fn);
+ blk_queue_issue_unprotect_fn(sdev->request_queue, ata_scsi_issue_unprotect_fn);

return 0; /* scsi layer doesn't check return value, sigh */
}
diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index 0a05a37..8094ba0 100644
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -731,6 +731,145 @@ static int idedisk_issue_flush(request_q
}

/*
+ * todo:
+ * - we freeze the queue regardless of success and rely on the
+ * ide_protect_queue function to thaw immediately if the command
+ * failed (to be consistent with the libata handler)... should
+ * we also inspect here?
+ */
+void ide_end_protect_rq(struct request *rq, int error)
+{
+ struct completion *waiting = rq->end_io_data;
+
+ rq->end_io_data = NULL;
+ /* spin lock already accquired */
+ if (!blk_queue_stopped(rq->q))
+ blk_stop_queue(rq->q);
+
+ complete(waiting);
+}
+
+int ide_unprotect_queue(request_queue_t *q)
+{
+ struct request rq;
+ unsigned long flags;
+ int pending = 0, rc = 0;
+ ide_drive_t *drive = q->queuedata;
+ u8 args[7], *argbuf = args;
+
+ if (!blk_queue_stopped(q))
+ return -EIO;
+
+ /* Are there any pending jobs on the queue? */
+ pending = ((q->rq.count[READ] > 0) || (q->rq.count[WRITE] > 0)) ? 1 : 0;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ blk_start_queue(q);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+
+ /* The unload feature of the IDLE_IMMEDIATE command
+ temporarily disables HD power management from spinning down
+ the disk. Any other command will reenable HD pm, so, if
+ there are no pending jobs on the queue, another
+ CHECK_POWER_MODE1 command without the unload feature should do
+ just fine. */
+ if (!pending) {
+ printk(KERN_DEBUG "ide_unprotect_queue(): No pending I/O, re-enabling power management..\n");
+ memset(args, 0, sizeof(args));
+ argbuf[0] = 0xe5; /* CHECK_POWER_MODE1 */
+ ide_init_drive_cmd(&rq);
+ rq.cmd_type = REQ_TYPE_ATA_TASK;
+ rq.buffer = argbuf;
+ rc = ide_do_drive_cmd(drive, &rq, ide_head_wait);
+ }
+
+ return rc;
+}
+
+int ide_protect_queue(request_queue_t *q, int unload)
+{
+ ide_drive_t *drive = q->queuedata;
+ struct request rq;
+ u8 args[7], *argbuf = args;
+ int ret = 0;
+ DECLARE_COMPLETION(wait);
+
+ memset(&rq, 0, sizeof(rq));
+ memset(args, 0, sizeof(args));
+
+ if (blk_queue_stopped(q))
+ return -EIO;
+
+ if (unload) {
+ argbuf[0] = 0xe1;
+ argbuf[1] = 0x44;
+ argbuf[3] = 0x4c;
+ argbuf[4] = 0x4e;
+ argbuf[5] = 0x55;
+ } else
+ argbuf[0] = 0xe0;
+
+ /* Issue the park command & freeze */
+ ide_init_drive_cmd(&rq);
+
+ rq.cmd_type = REQ_TYPE_ATA_TASK;
+ rq.buffer = argbuf;
+ rq.end_io_data = &wait;
+ rq.end_io = ide_end_protect_rq;
+
+ ret = ide_do_drive_cmd(drive, &rq, ide_next);
+ wait_for_completion(&wait);
+
+ if (ret)
+ {
+ printk(KERN_DEBUG "ide_protect_queue(): Warning: head NOT parked!..\n");
+ ide_unprotect_queue(q);
+ return ret;
+ }
+
+ if (unload) {
+ if (args[3] == 0xc4)
+ printk(KERN_DEBUG "ide_protect_queue(): head parked..\n");
+ else {
+ /* error parking the head */
+ printk(KERN_DEBUG "ide_protect_queue(): head NOT parked!..\n");
+ ret = -EIO;
+ ide_unprotect_queue(q);
+ }
+ } else
+ printk(KERN_DEBUG "ide_protect_queue(): head park not requested, used standby!..\n");
+
+ return ret;
+}
+
+int idedisk_issue_protect_fn(request_queue_t *q)
+{
+ ide_drive_t *drive = q->queuedata;
+ int unload;
+ unsigned long flags;
+
+ /*
+ * Check capability of the device -
+ * - if "idle immediate with unload" is supported we use that, else
+ * we use "standby immediate" and live with spinning down the drive..
+ * (Word 84, bit 13 of IDENTIFY DEVICE data)
+ */
+ if (unload == 2) {
+ unload = drive->id->cfsse & (1 << 13) ? 1 : 0;
+ spin_lock_irqsave(q->queue_lock, flags);
+ q->protect_method = unload;
+ spin_unlock_irqrestore(q->queue_lock, flags);
+ }
+
+ return ide_protect_queue(q, unload);
+}
+
+int idedisk_issue_unprotect_fn(request_queue_t *q)
+{
+ return ide_unprotect_queue(q);
+}
+
+/*
* This is tightly woven into the driver->do_special can not touch.
* DON'T do it again until a total personality rewrite is committed.
*/
@@ -986,6 +1125,9 @@ static void idedisk_setup (ide_drive_t *
drive->wcache = 1;

write_cache(drive, 1);
+
+ blk_queue_issue_protect_fn(drive->queue, idedisk_issue_protect_fn);
+ blk_queue_issue_unprotect_fn(drive->queue, idedisk_issue_unprotect_fn);
}

static void ide_cacheflush_p(ide_drive_t *drive)
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 2614f41..c026ae0 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -1261,6 +1261,17 @@ #endif
}

/*
+ * Don't accept a request when the queue is stopped (unless we
+ * are resuming from suspend). Prevents existing queue entries
+ * being processed after queue is stopped by the hard disk
+ * protection mechanism...
+ */
+ if (test_bit(QUEUE_FLAG_STOPPED, &drive->queue->queue_flags) && !blk_pm_resume_request(rq)) {
+ hwgroup->busy = 0;
+ break;
+ }
+
+ /*
* Sanity: don't accept a request that isn't a PM request
* if we are currently power managed. This is very important as
* blk_stop_queue() doesn't prevent the elv_next_request()
@@ -1744,6 +1755,9 @@ int ide_do_drive_cmd (ide_drive_t *drive
where = ELEVATOR_INSERT_FRONT;
rq->cmd_flags |= REQ_PREEMPT;
}
+ if (action == ide_next)
+ where = ELEVATOR_INSERT_FRONT;
+
__elv_add_request(drive->queue, rq, where, 0);
ide_do_request(hwgroup, IDE_NO_IRQ);
spin_unlock_irqrestore(&ide_lock, flags);
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 3ac4890..cbb274d 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2259,3 +2259,166 @@ void scsi_kunmap_atomic_sg(void *virt)
kunmap_atomic(virt, KM_BIO_SRC_IRQ);
}
EXPORT_SYMBOL(scsi_kunmap_atomic_sg);
+
+/*
+ * Structure required for synchronous io completion after queue freezing
+ */
+struct scsi_protect_io_context_sync {
+ struct scsi_device *sdev;
+ int result;
+ char *sense;
+ struct completion *waiting;
+};
+
+/*
+ * scsi_protect_wait_done()
+ * Command completion handler for scsi_protect_queue().
+ *
+ * Unable to call scsi_internal_device_block() as
+ * scsi_end_request() already has the spinlock. So,
+ * we put the necessary functionality inline.
+ *
+ * todo:
+ * - we block the queue regardless of success and rely on the
+ * scsi_protect_queue function to unblock if the command
+ * failed... should we also inspect here?
+ */
+static void scsi_protect_wait_done(void *data, char *sense, int result, int resid)
+{
+ struct scsi_protect_io_context_sync *siocs = data;
+ struct completion *waiting = siocs->waiting;
+ request_queue_t *q = siocs->sdev->request_queue;
+
+ siocs->waiting = NULL;
+ siocs->result = result;
+ memcpy(siocs->sense, sense, SCSI_SENSE_BUFFERSIZE);
+
+ if (!scsi_device_set_state(siocs->sdev, SDEV_BLOCK))
+ blk_stop_queue(q);
+
+ complete(waiting);
+}
+
+/*
+ * scsi_unprotect_queue()
+ * - release the queue that was previously blocked
+ */
+int scsi_unprotect_queue(request_queue_t *q)
+{
+ struct scsi_device *sdev = q->queuedata;
+ int rc = 0, pending = 0;
+ u8 scsi_cmd[MAX_COMMAND_SIZE];
+ struct scsi_sense_hdr sshdr;
+
+ if (sdev->sdev_state != SDEV_BLOCK)
+ return -ENXIO;
+
+ /* Are there any pending jobs on the queue? */
+ pending = ((q->rq.count[READ] > 0) || (q->rq.count[WRITE] > 0)) ? 1 : 0;
+
+ rc = scsi_internal_device_unblock(sdev);
+ if (rc)
+ return rc;
+
+ if (!pending) {
+ printk(KERN_DEBUG "scsi_unprotect_queue(): No pending I/O, re-enabling power management..\n");
+
+ memset(scsi_cmd, 0, sizeof(scsi_cmd));
+ scsi_cmd[0] = ATA_16;
+ scsi_cmd[1] = (3 << 1); /* Non-data */
+ /* scsi_cmd[2] is already 0 -- no off.line, cc, or data xfer */
+ scsi_cmd[14] = 0xe5; /* CHECK_POWER_MODE1 */
+
+ /* Good values for timeout and retries? Values below
+ from scsi_ioctl_send_command() for default case... */
+ if (scsi_execute_req(sdev, scsi_cmd, DMA_NONE, NULL, 0, &sshdr,
+ (10*HZ), 5))
+ rc = -EIO;
+ }
+ return rc;
+}
+EXPORT_SYMBOL_GPL(scsi_unprotect_queue);
+
+/*
+ * scsi_protect_queue()
+ * - build and issue the park/standby command..
+ * - queue is blocked during command completion handler
+ */
+int scsi_protect_queue(request_queue_t *q, int unload)
+{
+ struct scsi_protect_io_context_sync siocs;
+ struct scsi_device *sdev = q->queuedata;
+ int rc = 0;
+ u8 args[7];
+ u8 scsi_cmd[MAX_COMMAND_SIZE];
+ unsigned char sense[SCSI_SENSE_BUFFERSIZE];
+ unsigned char *desc;
+ DECLARE_COMPLETION_ONSTACK(wait);
+
+ if (sdev->sdev_state != SDEV_RUNNING)
+ return -ENXIO;
+
+ memset(args, 0, sizeof(args));
+ memset(sense, 0, sizeof(sense));
+
+ if (unload) {
+ args[0] = 0xe1;
+ args[1] = 0x44;
+ args[3] = 0x4c;
+ args[4] = 0x4e;
+ args[5] = 0x55;
+ } else
+ args[0] = 0xe0;
+
+ memset(scsi_cmd, 0, sizeof(scsi_cmd));
+ scsi_cmd[0] = ATA_16;
+ scsi_cmd[1] = (3 << 1); /* Non-data */
+ scsi_cmd[2] = 0x20; /* no off.line, or data xfer, request cc */
+ scsi_cmd[4] = args[1];
+ scsi_cmd[6] = args[2];
+ scsi_cmd[8] = args[3];
+ scsi_cmd[10] = args[4];
+ scsi_cmd[12] = args[5];
+ scsi_cmd[14] = args[0];
+ siocs.sdev = sdev;
+ siocs.sense = sense;
+ siocs.waiting = &wait;
+
+ scsi_execute_async(sdev, scsi_cmd, COMMAND_SIZE(scsi_cmd[0]),
+ DMA_NONE, NULL, 0, 0, (10*HZ), 5,
+ &siocs, &scsi_protect_wait_done, GFP_NOWAIT);
+ wait_for_completion(&wait);
+
+ if (siocs.result != ((DRIVER_SENSE << 24) + SAM_STAT_CHECK_CONDITION)) {
+ printk(KERN_DEBUG "scsi_protect_queue(): head NOT parked!..\n");
+ scsi_unprotect_queue(q); /* just in case we still managed to block */
+ rc = -EIO;
+ goto out;
+ }
+
+ desc = sense + 8;
+
+ /* Retrieve data from check condition */
+ args[1] = desc[3];
+ args[2] = desc[5];
+ args[3] = desc[7];
+ args[4] = desc[9];
+ args[5] = desc[11];
+ args[0] = desc[13];
+
+ if (unload) {
+ if (args[3] == 0xc4)
+ printk(KERN_DEBUG "scsi_protect_queue(): head parked..\n");
+ else {
+ /* error parking the head */
+ printk(KERN_DEBUG "scsi_protect_queue(): head NOT parked!..\n");
+ rc = -EIO;
+ scsi_unprotect_queue(q);
+ }
+ } else
+ printk(KERN_DEBUG "scsi_protect_queue(): head park not requested, used standby!..\n");
+
+out:
+ return rc;
+}
+EXPORT_SYMBOL_GPL(scsi_protect_queue);
diff --git a/include/linux/ata.h b/include/linux/ata.h
index d894419..7b943d2 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -282,6 +282,7 @@ #define ata_id_is_sata(id) ((id)[93] ==
#define ata_id_rahead_enabled(id) ((id)[85] & (1 << 6))
#define ata_id_wcache_enabled(id) ((id)[85] & (1 << 5))
#define ata_id_hpa_enabled(id) ((id)[85] & (1 << 10))
+#define ata_id_has_unload(id) ((id)[84] & (1 << 13))
#define ata_id_has_fua(id) ((id)[84] & (1 << 6))
#define ata_id_has_flush(id) ((id)[83] & (1 << 12))
#define ata_id_has_flush_ext(id) ((id)[83] & (1 << 13))
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 7bfcde2..838e7b0 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -346,6 +346,8 @@ typedef void (activity_fn) (void *data,
typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *);
typedef void (prepare_flush_fn) (request_queue_t *, struct request *);
typedef void (softirq_done_fn)(struct request *);
+typedef int (issue_protect_fn) (request_queue_t *);
+typedef int (issue_unprotect_fn) (request_queue_t *);

enum blk_queue_state {
Queue_down,
@@ -388,6 +390,8 @@ struct request_queue
issue_flush_fn *issue_flush_fn;
prepare_flush_fn *prepare_flush_fn;
softirq_done_fn *softirq_done_fn;
+ issue_protect_fn *issue_protect_fn;
+ issue_unprotect_fn *issue_unprotect_fn;

/*
* Dispatch queue sorting
@@ -403,6 +407,14 @@ struct request_queue
unsigned long unplug_delay; /* After this many jiffies */
struct work_struct unplug_work;

+ /*
+ * Auto-unfreeze state
+ */
+ struct timer_list unfreeze_timer;
+ int max_unfreeze; /* At most this many seconds */
+ struct work_struct unfreeze_work;
+ int protect_method;
+
struct backing_dev_info backing_dev_info;

/*
@@ -760,6 +772,8 @@ extern int blk_do_ordered(request_queue_
extern unsigned blk_ordered_cur_seq(request_queue_t *);
extern unsigned blk_ordered_req_seq(struct request *);
extern void blk_ordered_complete_seq(request_queue_t *, unsigned, int);
+extern void blk_queue_issue_protect_fn(request_queue_t *, issue_protect_fn *);
+extern void blk_queue_issue_unprotect_fn(request_queue_t *, issue_unprotect_fn *);

extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *);
extern void blk_dump_rq_flags(struct request *, char *);
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 9c20502..8613b94 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -1090,6 +1090,7 @@ extern u64 ide_get_error_location(ide_dr
*/
typedef enum {
ide_wait, /* insert rq at end of list, and wait for it */
+ ide_next, /* insert rq immediately after current request */
ide_preempt, /* insert rq in front of current request */
ide_head_wait, /* insert rq in front of current request and wait for it */
ide_end /* insert rq at end of list, but don't wait for it */