block: Expose discard granularity
While SSDs track block usage on a per-sector basis, RAID arrays often
have allocation blocks that are bigger. Allow the discard granularity
and alignment to be set and teach the topology stacking logic how to
handle them.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index 7b685e1..64bc899 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -226,6 +226,13 @@
return sprintf(buf, "%llu\n", (unsigned long long)p->alignment_offset);
}
+ssize_t part_discard_alignment_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hd_struct *p = dev_to_part(dev);
+ return sprintf(buf, "%u\n", p->discard_alignment);
+}
+
ssize_t part_stat_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -288,6 +295,8 @@
static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
static DEVICE_ATTR(alignment_offset, S_IRUGO, part_alignment_offset_show, NULL);
+static DEVICE_ATTR(discard_alignment, S_IRUGO, part_discard_alignment_show,
+ NULL);
static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL);
#ifdef CONFIG_FAIL_MAKE_REQUEST
@@ -300,6 +309,7 @@
&dev_attr_start.attr,
&dev_attr_size.attr,
&dev_attr_alignment_offset.attr,
+ &dev_attr_discard_alignment.attr,
&dev_attr_stat.attr,
&dev_attr_inflight.attr,
#ifdef CONFIG_FAIL_MAKE_REQUEST
@@ -403,6 +413,8 @@
p->start_sect = start;
p->alignment_offset = queue_sector_alignment_offset(disk->queue, start);
+ p->discard_alignment = queue_sector_discard_alignment(disk->queue,
+ start);
p->nr_sects = len;
p->partno = partno;
p->policy = get_disk_ro(disk);