[PATCH 1/6] md: switch to ->check_events for media change notifications

Christoph Hellwig
2020-07-08T12:45:29Z

md is the last driver using the legacy media_changed method. Switch
it over to (not so) new ->clear_events approach, which also removes the
need for the ->revalidate_disk method.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
Documentation/filesystems/locking.rst | 4 +---
block/genhd.c | 7 +------
drivers/md/md.c | 19 ++++++++-----------
include/linux/blkdev.h | 2 --
4 files changed, 10 insertions(+), 22 deletions(-)

diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst
index 318605de83f33c..17bea12538c32d 100644
--- a/Documentation/filesystems/locking.rst
+++ b/Documentation/filesystems/locking.rst
@@ -467,7 +467,6 @@ prototypes::
int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
int (*direct_access) (struct block_device *, sector_t, void **,
unsigned long *);
- int (*media_changed) (struct gendisk *);
void (*unlock_native_capacity) (struct gendisk *);
int (*revalidate_disk) (struct gendisk *);
int (*getgeo)(struct block_device *, struct hd_geometry *);
@@ -483,14 +482,13 @@ release: yes
ioctl: no
compat_ioctl: no
direct_access: no
-media_changed: no
unlock_native_capacity: no
revalidate_disk: no
getgeo: no
swap_slot_free_notify: no (see below)
======================= ===================

-media_changed, unlock_native_capacity and revalidate_disk are called only from
+unlock_native_capacity and revalidate_disk are called only from
check_disk_change().

swap_slot_free_notify is called with swap_lock and sometimes the page lock
diff --git a/block/genhd.c b/block/genhd.c
index 60ae4e1b4d3877..1070da9d4d9a77 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -2061,13 +2061,8 @@ unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
unsigned int pending;
unsigned int clearing = mask;

- if (!ev) {
- /* for drivers still using the old ->media_changed method */
- if ((mask & DISK_EVENT_MEDIA_CHANGE) &&
- bdops->media_changed && bdops->media_changed(disk))
- return DISK_EVENT_MEDIA_CHANGE;
+ if (!ev)
return 0;
- }

disk_block_events(disk);

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 8bb69c61afe086..77dfe4765c3111 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5670,6 +5670,7 @@ static int md_alloc(dev_t dev, char *name)
* remove it now.
*/
disk->flags |= GENHD_FL_EXT_DEVT;
+ disk->events |= DISK_EVENT_MEDIA_CHANGE;
mddev->gendisk = disk;
/* As soon as we call add_disk(), another thread could get
* through to md_open, so make sure it doesn't get too far
@@ -7806,20 +7807,17 @@ static void md_release(struct gendisk *disk, fmode_t mode)
mddev_put(mddev);
}

-static int md_media_changed(struct gendisk *disk)
-{
- struct mddev *mddev = disk->private_data;
-
- return mddev->changed;
-}
-
-static int md_revalidate(struct gendisk *disk)
+static unsigned int md_check_events(struct gendisk *disk, unsigned int clearing)
{
struct mddev *mddev = disk->private_data;
+ unsigned int ret = 0;

+ if (mddev->changed)
+ ret = DISK_EVENT_MEDIA_CHANGE;
mddev->changed = 0;
- return 0;
+ return ret;
}
+
static const struct block_device_operations md_fops =
{
.owner = THIS_MODULE,
@@ -7831,8 +7829,7 @@ static const struct block_device_operations md_fops =
.compat_ioctl = md_compat_ioctl,
#endif
.getgeo = md_getgeo,
- .media_changed = md_media_changed,
- .revalidate_disk= md_revalidate,
+ .check_events = md_check_events,
};

static int md_thread(void *arg)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 408eb66a82fdc7..71173a1ffa8b87 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1781,8 +1781,6 @@ struct block_device_operations {
int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
unsigned int (*check_events) (struct gendisk *disk,
unsigned int clearing);
- /* ->media_changed() is DEPRECATED, use ->check_events() instead */
- int (*media_changed) (struct gendisk *);
void (*unlock_native_capacity) (struct gendisk *);
int (*revalidate_disk) (struct gendisk *);
int (*getgeo)(struct block_device *, struct hd_geometry *);
--
2.26.2