block: export SSD/non-rotational queue flag through sysfs
For some devices (i.e. CFA ATA) we can't reliably detect whether
the device is of rotational or non-rotational type so we need to
leave the final decision about this setting to the user-space.
As a bonus do a minor CodingStyle fixup in queue_nomerges_store().
Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index a29cb78..b538ab8 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -130,6 +130,27 @@
return queue_var_show(max_hw_sectors_kb, (page));
}
+static ssize_t queue_nonrot_show(struct request_queue *q, char *page)
+{
+ return queue_var_show(!blk_queue_nonrot(q), page);
+}
+
+static ssize_t queue_nonrot_store(struct request_queue *q, const char *page,
+ size_t count)
+{
+ unsigned long nm;
+ ssize_t ret = queue_var_store(&nm, page, count);
+
+ spin_lock_irq(q->queue_lock);
+ if (nm)
+ queue_flag_clear(QUEUE_FLAG_NONROT, q);
+ else
+ queue_flag_set(QUEUE_FLAG_NONROT, q);
+ spin_unlock_irq(q->queue_lock);
+
+ return ret;
+}
+
static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
{
return queue_var_show(blk_queue_nomerges(q), page);
@@ -146,8 +167,8 @@
queue_flag_set(QUEUE_FLAG_NOMERGES, q);
else
queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
-
spin_unlock_irq(q->queue_lock);
+
return ret;
}
@@ -210,6 +231,12 @@
.show = queue_hw_sector_size_show,
};
+static struct queue_sysfs_entry queue_nonrot_entry = {
+ .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_nonrot_show,
+ .store = queue_nonrot_store,
+};
+
static struct queue_sysfs_entry queue_nomerges_entry = {
.attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
.show = queue_nomerges_show,
@@ -229,6 +256,7 @@
&queue_max_sectors_entry.attr,
&queue_iosched_entry.attr,
&queue_hw_sector_size_entry.attr,
+ &queue_nonrot_entry.attr,
&queue_nomerges_entry.attr,
&queue_rq_affinity_entry.attr,
NULL,