block: Remove extra discard_alignment from hd_struct.

Currently, hd_struct.discard_alignment is only used when we
show /sys/block/sdx/sdx/discard_alignment. So remove it and
calculate when it is asked to show.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

2 files changed, 6 insertions, 4 deletions

diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index d545e97d99c3..b7e16bccd5e5 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -255,7 +255,12 @@ 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);
+        struct gendisk *disk = dev_to_disk(dev);
+
+        return sprintf(buf, "%u\n",
+                       (unsigned long long)queue_limit_discard_alignment(
+                                                        &disk->queue->limits,
+                                                        p->start_sect));
 }
 
 ssize_t part_stat_show(struct device *dev,
@@ -449,8 +454,6 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno,
         p->start_sect = start;
         p->alignment_offset =
                 queue_limit_alignment_offset(&disk->queue->limits, start);
-        p->discard_alignment =
-                queue_limit_discard_alignment(&disk->queue->limits, start);
         p->nr_sects = len;
         p->partno = partno;
         p->policy = get_disk_ro(disk);
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 300d7582006e..b78956b3c2e7 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -100,7 +100,6 @@ struct hd_struct {
         sector_t start_sect;
         sector_t nr_sects;
         sector_t alignment_offset;
-        unsigned int discard_alignment;
         struct device __dev;
         struct kobject *holder_dir;
         int policy, partno;