Hard disk protection revisited

diff -urN linux-2.6.14-rc3.passthru/drivers/block/ll_rw_blk.c linux-2.6.14-rc3.hdaps/drivers/block/ll_rw_blk.c
@@ -38,6 +38,8 @@
 static void blk_unplug_work(void *data);
 static void blk_unplug_timeout(unsigned long data);
 static void drive_stat_acct(struct request *rq, int nr_sectors, int new_io);
+static int blk_protect_register(request_queue_t *q);
+static void blk_protect_unregister(request_queue_t *q);
 
 /*
  * For the allocated request tables

@@ -345,6 +347,18 @@
 
 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
  */

@@ -3693,6 +3707,7 @@
 		return ret;
 	}
 
+	blk_protect_register(q);
 	return 0;
 }
 

@@ -3701,9 +3716,121 @@
 	request_queue_t *q = disk->queue;
 
 	if (q && q->request_fn) {
+		blk_protect_unregister(q);
 		elv_unregister_queue(q);
 
 		kobject_unregister(&q->kobj);
 		kobject_put(&disk->kobj);
 	}
 }
+
+/*
+ * Restore the unplugging timer that we re-used
+ * to implement the queue freeze timeout...
+ */
+static void blk_unfreeze_work(void *data)
+{
+	request_queue_t *q = (request_queue_t *) data;
+
+	INIT_WORK(&q->unplug_work, blk_unplug_work, q);
+	q->unplug_timer.function = blk_unplug_timeout;
+
+	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->unplug_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)
+{
+	/* set/reset the timer */
+	mod_timer(&q->unplug_timer, msecs_to_jiffies(seconds*1000) + jiffies);
+
+	/* we do this every iteration - is this sane? */
+	INIT_WORK(&q->unplug_work, blk_unfreeze_work, q);
+	q->unplug_timer.function = blk_unfreeze_timeout;
+}
+
+/* 
+ * When reading the 'protect' attribute, we return boolean frozen or active
+ * todo:
+ * - maybe we should return seconds remaining instead?
+ */
+static ssize_t queue_protect_show(struct request_queue *q, char *page)
+{
+	return queue_var_show(blk_queue_stopped(q), (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);
+
+	printk(KERN_DEBUG "queue_protect_store(): freeze = %lu\n", freeze);
+
+	if(freeze>0) {
+		/* Park and freeze */
+		if (!blk_queue_stopped(q))
+			q->issue_protect_fn(q);
+		/* set / reset the thaw timer */
+		blk_freeze_queue(q, freeze);
+	}
+	else
+		blk_unfreeze_timeout((unsigned long) q);
+
+	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 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 attribute */
+	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);
+	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 attribute */
+	sysfs_remove_file(&q->kobj,&queue_protect_entry.attr);
+	kobject_put(&q->kobj);
+}

125 lines not on this page · raw message

diff -urN linux-2.6.14-rc3.passthru/drivers/ide/ide-io.c linux-2.6.14-rc3.hdaps/drivers/ide/ide-io.c
@@ -1181,6 +1181,17 @@
 		}
 
 		/*
+		 * 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()

@@ -1661,6 +1672,9 @@
 		where = ELEVATOR_INSERT_FRONT;
 		rq->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 -urN linux-2.6.14-rc3.passthru/drivers/scsi/libata-scsi.c linux-2.6.14-rc3.hdaps/drivers/scsi/libata-scsi.c
@@ -607,6 +607,29 @@
 	}
 }
 
+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];
+
+	if (ata_id_has_unload(dev->id))
+		printk(KERN_DEBUG "ata_scsi_issue_protect_fn(): unload support reported..\n");
+	else
+		printk(KERN_DEBUG "ata_scsi_issue_protect_fn(): unload support NOT reported..\n");
+
+	/* call scsi_protect_queue, requesting either unload or standby */
+	return scsi_protect_queue(q, ata_id_has_unload(dev->id) ? 1 : 0);
+}
+
+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

@@ -647,6 +670,8 @@
 			blk_queue_max_sectors(sdev->request_queue, 2048);
 		}
 	}
+	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 */
 }

167 lines not on this page · raw message

diff -urN linux-2.6.14-rc3.passthru/include/linux/ata.h linux-2.6.14-rc3.hdaps/include/linux/ata.h
@@ -234,6 +234,7 @@
 #define ata_id_is_sata(id)	((id)[93] == 0)
 #define ata_id_rahead_enabled(id) ((id)[85] & (1 << 6))
 #define ata_id_wcache_enabled(id) ((id)[85] & (1 << 5))
+#define ata_id_has_unload(id) ((id)[84] & (1 << 13))
 #define ata_id_has_flush(id) ((id)[83] & (1 << 12))
 #define ata_id_has_flush_ext(id) ((id)[83] & (1 << 13))
 #define ata_id_has_lba48(id)	((id)[83] & (1 << 10))

diff -urN linux-2.6.14-rc3.passthru/include/linux/blkdev.h linux-2.6.14-rc3.hdaps/include/linux/blkdev.h
@@ -287,6 +287,8 @@
 typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *);
 typedef void (activity_fn) (void *data, int rw);
 typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *);
+typedef int (issue_protect_fn) (request_queue_t *);
+typedef int (issue_unprotect_fn) (request_queue_t *);
 typedef int (prepare_flush_fn) (request_queue_t *, struct request *);
 typedef void (end_flush_fn) (request_queue_t *, struct request *);
 

@@ -331,6 +333,8 @@
 	issue_flush_fn		*issue_flush_fn;
 	prepare_flush_fn	*prepare_flush_fn;
 	end_flush_fn		*end_flush_fn;
+	issue_protect_fn	*issue_protect_fn;
+	issue_unprotect_fn	*issue_unprotect_fn;
 
 	/*
 	 * Auto-unplugging state

@@ -644,6 +648,8 @@
 extern struct request *blk_start_pre_flush(request_queue_t *,struct request *);
 extern int blk_complete_barrier_rq(request_queue_t *, struct request *, int);
 extern int blk_complete_barrier_rq_locked(request_queue_t *, struct request *, 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 *);