Allow block/genhd to notify user space (via udev) about disk size changes
using a new helper disk_set_capacity(), which is a wrapper on top
of set_capacity(). disk_set_capacity() will only notify via udev if
the current capacity or the target capacity is not zero.
Background:
As a part of a patch to allow sending the RESIZE event on disk capacity
change, Christoph ([email protected]) requested that the patch be made generic
and the hacks for virtio block and xen block devices be removed and
merged via a generic helper.
Testing:
1. I did some basic testing with an NVME device, by resizing it in
the backend and ensured that udevd received the event.
Suggested-by: Christoph Hellwig <[email protected]>
Signed-off-by: Balbir Singh <[email protected]>
Signed-off-by: Someswarudu Sangaraju <[email protected]>
Signed-off-by: Balbir Singh <[email protected]>
---
block/genhd.c | 19 +++++++++++++++++++
include/linux/genhd.h | 1 +
2 files changed, 20 insertions(+)
diff --git a/block/genhd.c b/block/genhd.c
index ff6268970ddc..94faec98607b 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -46,6 +46,25 @@ static void disk_add_events(struct gendisk *disk);
static void disk_del_events(struct gendisk *disk);
static void disk_release_events(struct gendisk *disk);
+/*
+ * Set disk capacity and notify if the size is not currently
+ * zero and will not be set to zero
+ */
+void disk_set_capacity(struct gendisk *disk, sector_t size)
+{
+ sector_t capacity = get_capacity(disk);
+
+ set_capacity(disk, size);
+ if (capacity != 0 && size != 0) {
+ char *envp[] = { "RESIZE=1", NULL };
+
+ kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
+ }
+}
+
+EXPORT_SYMBOL_GPL(disk_set_capacity);
+
+
void part_inc_in_flight(struct request_queue *q, struct hd_struct *part, int rw)
{
if (queue_is_mq(q))
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index a927829bb73a..f1a5ddcc781d 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -449,6 +449,7 @@ static inline int get_disk_ro(struct gendisk *disk)
extern void disk_block_events(struct gendisk *disk);
extern void disk_unblock_events(struct gendisk *disk);
extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
+extern void disk_set_capacity(struct gendisk *disk, sector_t size);
extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);
/* drivers/char/random.c */
--
2.16.5
block/genhd provides disk_set_capacity() for sending
RESIZE notifications via uevents.
Signed-off-by: Balbir Singh <[email protected]>
---
drivers/block/xen-blkfront.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 23c86350a5ab..bed7050a697d 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -2337,7 +2337,6 @@ static void blkfront_connect(struct blkfront_info *info)
unsigned long sector_size;
unsigned int physical_sector_size;
unsigned int binfo;
- char *envp[] = { "RESIZE=1", NULL };
int err, i;
switch (info->connected) {
@@ -2352,10 +2351,8 @@ static void blkfront_connect(struct blkfront_info *info)
return;
printk(KERN_INFO "Setting capacity to %Lu\n",
sectors);
- set_capacity(info->gd, sectors);
+ disk_set_capacity(info->gd, sectors);
revalidate_disk(info->gd);
- kobject_uevent_env(&disk_to_dev(info->gd)->kobj,
- KOBJ_CHANGE, envp);
return;
case BLKIF_STATE_SUSPENDED:
--
2.16.5
block/genhd provides disk_set_capacity() for sending
RESIZE notifications via uevents.
Signed-off-by: Balbir Singh <[email protected]>
---
drivers/block/virtio_blk.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index fbbf18ac1d5d..9848c94a7eb4 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -479,18 +479,16 @@ static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize)
cap_str_10,
cap_str_2);
- set_capacity(vblk->disk, capacity);
+ disk_set_capacity(vblk->disk, capacity);
}
static void virtblk_config_changed_work(struct work_struct *work)
{
struct virtio_blk *vblk =
container_of(work, struct virtio_blk, config_work);
- char *envp[] = { "RESIZE=1", NULL };
virtblk_update_capacity(vblk, true);
revalidate_disk(vblk->disk);
- kobject_uevent_env(&disk_to_dev(vblk->disk)->kobj, KOBJ_CHANGE, envp);
}
static void virtblk_config_changed(struct virtio_device *vdev)
--
2.16.5
On Mon, 2019-12-23 at 01:40 +0000, Balbir Singh wrote:
> Allow block/genhd to notify user space (via udev) about disk size changes
> using a new helper disk_set_capacity(), which is a wrapper on top
> of set_capacity(). disk_set_capacity() will only notify via udev if
> the current capacity or the target capacity is not zero.
>
> Background:
>
> As a part of a patch to allow sending the RESIZE event on disk capacity
> change, Christoph ([email protected]) requested that the patch be made generic
> and the hacks for virtio block and xen block devices be removed and
> merged via a generic helper.
>
>
I messed up with linux-block ML address, I can resend with the right address
if needed. My apologies
Balbir Singh.
On 12/22/19 5:53 PM, Singh, Balbir wrote:
> I messed up with linux-block ML address, I can resend with the right address
> if needed. My apologies
>
> Balbir Singh.
Unless you have sent it already and I totally missed it,
if you are planning to resend can you please also add a cover-letter ?
On Wed, 2020-01-01 at 03:26 +0000, Chaitanya Kulkarni wrote:
> On 12/22/19 5:53 PM, Singh, Balbir wrote:
> > I messed up with linux-block ML address, I can resend with the right
> > address
> > if needed. My apologies
> >
> > Balbir Singh.
>
>
> Unless you have sent it already and I totally missed it,
> if you are planning to resend can you please also add a cover-letter ?
I did not resend it, I'll resend and add a cover letter.
Balbir Singh.