| Message ID | 20191210030131.4198-1-sblbir@amazon.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RFC] block/genhd: Notify udev about capacity change | expand |
On Tue, 2019-12-10 at 03:01 +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. > > disk_set_capacity() is not enabled for all devices, just virtio block, > xen-blockfront, nvme and sd. Owners of other block disk devices can > easily move over by changing set_capacity() to disk_set_capacity() > > Background: > > As a part of a patch to allow sending the RESIZE event on disk capacity > change, Christoph (hch@lst.de) 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 <hch@lst.de> > Signed-off-by: Balbir Singh <sblbir@amazon.com> > Signed-off-by: Someswarudu Sangaraju <ssomesh@amazon.com> > Any feedback on the RFC? Balbir Singh.
On Tue, Dec 10, 2019 at 03:01:31AM +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. > > disk_set_capacity() is not enabled for all devices, just virtio block, > xen-blockfront, nvme and sd. Owners of other block disk devices can > easily move over by changing set_capacity() to disk_set_capacity() > > Background: > > As a part of a patch to allow sending the RESIZE event on disk capacity > change, Christoph (hch@lst.de) 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 <hch@lst.de> > Signed-off-by: Balbir Singh <sblbir@amazon.com> > Signed-off-by: Someswarudu Sangaraju <ssomesh@amazon.com> > --- > block/genhd.c | 19 +++++++++++++++++++ > drivers/block/virtio_blk.c | 4 +--- > drivers/block/xen-blkfront.c | 5 +---- > drivers/nvme/host/core.c | 2 +- > drivers/scsi/sd.c | 2 +- > include/linux/genhd.h | 1 + > 6 files changed, 24 insertions(+), 9 deletions(-) > > 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 Nit: Use up all the 80 chars per line. Also maybe turn this into a kerneldoc comment. I think you also want to mention the notification as well. > +EXPORT_SYMBOL_GPL(disk_set_capacity); > + > + > void part_inc_in_flight(struct request_queue *q, struct hd_struct *part, int rw) No need for the double empty line. > { > if (queue_is_mq(q)) > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > index 7ffd719d89de..869cd3c31529 100644 > --- a/drivers/block/virtio_blk.c > +++ b/drivers/block/virtio_blk.c And you probably want to turn this into a series with patch 1 adding the infrastructure, and then one patch per driver switched over.
On Thu, 2019-12-12 at 10:54 +0100, Christoph Hellwig wrote: > On Tue, Dec 10, 2019 at 03:01:31AM +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. > > > > disk_set_capacity() is not enabled for all devices, just virtio block, > > xen-blockfront, nvme and sd. Owners of other block disk devices can > > easily move over by changing set_capacity() to disk_set_capacity() > > > > Background: > > > > As a part of a patch to allow sending the RESIZE event on disk capacity > > change, Christoph (hch@lst.de) 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 <hch@lst.de> > > Signed-off-by: Balbir Singh <sblbir@amazon.com> > > Signed-off-by: Someswarudu Sangaraju <ssomesh@amazon.com> > > --- > > block/genhd.c | 19 +++++++++++++++++++ > > drivers/block/virtio_blk.c | 4 +--- > > drivers/block/xen-blkfront.c | 5 +---- > > drivers/nvme/host/core.c | 2 +- > > drivers/scsi/sd.c | 2 +- > > include/linux/genhd.h | 1 + > > 6 files changed, 24 insertions(+), 9 deletions(-) > > > > 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 > > Nit: Use up all the 80 chars per line. Also maybe turn this into a > kerneldoc comment. I think you also want to mention the notification > as well. Will do! > > > +EXPORT_SYMBOL_GPL(disk_set_capacity); > > + > > + > > void part_inc_in_flight(struct request_queue *q, struct hd_struct *part, > > int rw) > > No need for the double empty line. > > > { > > if (queue_is_mq(q)) > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > > index 7ffd719d89de..869cd3c31529 100644 > > --- a/drivers/block/virtio_blk.c > > +++ b/drivers/block/virtio_blk.c > > And you probably want to turn this into a series with patch 1 adding > the infrastructure, and then one patch per driver switched over. Makes sense, will do Thanks for the feedback Balbir Singh.
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/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 7ffd719d89de..869cd3c31529 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -476,18 +476,16 @@ 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) diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index a74d03913822..8077c070fe18 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: diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index dfe37a525f3a..f1ad70aab721 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -1806,7 +1806,7 @@ static void nvme_update_disk_info(struct gendisk *disk, ns->lba_shift > PAGE_SHIFT) capacity = 0; - set_capacity(disk, capacity); + disk_set_capacity(disk, capacity); nvme_config_discard(disk, ns); nvme_config_write_zeroes(disk, ns); diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index cea625906440..afeae847dca6 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -3196,7 +3196,7 @@ static int sd_revalidate_disk(struct gendisk *disk) sdkp->first_scan = 0; - set_capacity(disk, logical_to_sectors(sdp, sdkp->capacity)); + disk_set_capacity(disk, logical_to_sectors(sdp, sdkp->capacity)); sd_config_write_same(sdkp); kfree(buffer); diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 8bb63027e4d6..d5e87d7cc357 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 */