2020-03-13 05:31:18

by Singh, Balbir

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Subject: [PATCH v3 0/5] Add support for block disk resize notification

Allow block/genhd to notify user space about disk size changes using a
new helper set_capacity_revalidate_and_notify(), which is a wrapper
on top of set_capacity(). set_capacity_revalidate_and_notify() will only notify
iff the current capacity or the target capacity is not zero and the
capacity really changes.

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.

This series consists of 5 changes. The first one adds the basic
support for changing the size and notifying. The follow up patches
are per block subsystem changes. Other block drivers can add their
changes as necessary on top of this series. Since not all devices
are resizable, the default was to add a new API and let users
slowly convert over as needed.

Testing:
1. I did some basic testing with an NVME device, by resizing it in
the backend and ensured that udevd received the event.


Changelog v3:
- Repost after rebasing
- Trim details of the subsystem/files in the subject
Changelog v2:
- Rename disk_set_capacity to set_capacity_revalidate_and_notify
- set_capacity_revalidate_and_notify can call revalidate disk
if needed, a new bool parameter is passed (suggested by Bob Liu)

Balbir Singh (5):
block/genhd: Notify udev about capacity change
virtio_blk.c: Convert to use set_capacity_revalidate_and_notify
xen-blkfront.c: Convert to use set_capacity_revalidate_and_notify
nvme: Convert to use set_capacity_revalidate_and_notify
scsi: Convert to use set_capacity_revalidate_and_notify

block/genhd.c | 24 ++++++++++++++++++++++++
drivers/block/virtio_blk.c | 5 +----
drivers/block/xen-blkfront.c | 6 +-----
drivers/nvme/host/core.c | 2 +-
drivers/scsi/sd.c | 3 ++-
include/linux/genhd.h | 2 ++
6 files changed, 31 insertions(+), 11 deletions(-)

--
2.16.6


2020-03-13 05:31:33

by Singh, Balbir

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Subject: [PATCH v3 5/5] scsi: Convert to use set_capacity_revalidate_and_notify

block/genhd provides set_capacity_revalidate_and_notify() for sending RESIZE
notifications via uevents. This notification is newly added to scsi sd.

Signed-off-by: Balbir Singh <[email protected]>
---
drivers/scsi/sd.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 8ca9299ffd36..707f47c0ec98 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3187,7 +3187,8 @@ static int sd_revalidate_disk(struct gendisk *disk)

sdkp->first_scan = 0;

- set_capacity(disk, logical_to_sectors(sdp, sdkp->capacity));
+ set_capacity_revalidate_and_notify(disk,
+ logical_to_sectors(sdp, sdkp->capacity), false);
sd_config_write_same(sdkp);
kfree(buffer);

--
2.16.6

2020-03-13 05:31:45

by Singh, Balbir

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Subject: [PATCH v3 3/5] xen-blkfront.c: Convert to use set_capacity_revalidate_and_notify

block/genhd provides set_capacity_revalidate_and_notify() for
sending RESIZE notifications via uevents.

Signed-off-by: Balbir Singh <[email protected]>
---
drivers/block/xen-blkfront.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 9df516a56bb2..915cf5b6388c 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -2338,7 +2338,6 @@ 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;
struct blkfront_ring_info *rinfo;

@@ -2354,10 +2353,7 @@ static void blkfront_connect(struct blkfront_info *info)
return;
printk(KERN_INFO "Setting capacity to %Lu\n",
sectors);
- set_capacity(info->gd, sectors);
- revalidate_disk(info->gd);
- kobject_uevent_env(&disk_to_dev(info->gd)->kobj,
- KOBJ_CHANGE, envp);
+ set_capacity_revalidate_and_notify(info->gd, sectors, true);

return;
case BLKIF_STATE_SUSPENDED:
--
2.16.6

2020-03-13 05:31:54

by Singh, Balbir

[permalink] [raw]
Subject: [PATCH v3 4/5] nvme: Convert to use set_capacity_revalidate_and_notify

block/genhd provides set_capacity_revalidate_and_notify() for
sending RESIZE notifications via uevents. This notification is
newly added to NVME devices

Signed-off-by: Balbir Singh <[email protected]>
Acked-by: Keith Busch <[email protected]>
Reviewed-by: Sagi Grimberg <[email protected]>
---
drivers/nvme/host/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index a4d8c90ee7cc..41ad07f6a564 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1810,7 +1810,7 @@ static void nvme_update_disk_info(struct gendisk *disk,
ns->lba_shift > PAGE_SHIFT)
capacity = 0;

- set_capacity(disk, capacity);
+ set_capacity_revalidate_and_notify(disk, capacity, false);

nvme_config_discard(disk, ns);
nvme_config_write_zeroes(disk, ns);
--
2.16.6

2020-03-13 11:12:05

by Christoph Hellwig

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Subject: Re: [PATCH v3 4/5] nvme: Convert to use set_capacity_revalidate_and_notify

On Fri, Mar 13, 2020 at 05:30:08AM +0000, Balbir Singh wrote:
> block/genhd provides set_capacity_revalidate_and_notify() for
> sending RESIZE notifications via uevents. This notification is
> newly added to NVME devices
>
> Signed-off-by: Balbir Singh <[email protected]>
> Acked-by: Keith Busch <[email protected]>
> Reviewed-by: Sagi Grimberg <[email protected]>

Looks good,

Reviewed-by: Christoph Hellwig <[email protected]>

2020-03-13 11:12:16

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH v3 5/5] scsi: Convert to use set_capacity_revalidate_and_notify

On Fri, Mar 13, 2020 at 05:30:09AM +0000, Balbir Singh wrote:
> block/genhd provides set_capacity_revalidate_and_notify() for sending RESIZE
> notifications via uevents. This notification is newly added to scsi sd.
>
> Signed-off-by: Balbir Singh <[email protected]>

Looks good,

Reviewed-by: Christoph Hellwig <[email protected]>

2020-03-13 11:12:42

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH v3 3/5] xen-blkfront.c: Convert to use set_capacity_revalidate_and_notify

On Fri, Mar 13, 2020 at 05:30:07AM +0000, Balbir Singh wrote:
> block/genhd provides set_capacity_revalidate_and_notify() for
> sending RESIZE notifications via uevents.
>
> Signed-off-by: Balbir Singh <[email protected]>

Looks good,

Reviewed-by: Christoph Hellwig <[email protected]>