| Message ID | 20200102075315.22652-5-sblbir@amazon.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add support for block disk resize notification | expand |
Quick question here if user executes nvme ns-rescan /dev/nvme1 will following code result in triggering uevent(s) for the namespace(s( for which there is no change in the size ? If so is that an expected behavior ? On 01/01/2020 11:54 PM, Balbir Singh wrote: > block/genhd provides disk_set_capacity() for sending > RESIZE notifications via uevents. This notification is > newly added to NVME devices > > Signed-off-by: Balbir Singh <sblbir@amazon.com> > --- > 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 667f18f465be..cb214e914fc2 100644 > --- a/drivers/nvme/host/core.c > +++ b/drivers/nvme/host/core.c > @@ -1808,7 +1808,7 @@ 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); >
On Sat, 2020-01-04 at 22:27 +0000, Chaitanya Kulkarni wrote: > Quick question here if user executes nvme ns-rescan /dev/nvme1 > will following code result in triggering uevent(s) for > the namespace(s( for which there is no change in the size ? > > If so is that an expected behavior ? > My old code had a check to see if old_capacity != new_capacity as well. I can redo those bits if needed. The expected behaviour is not clear, but the functionality is not broken, user space should be able to deal with a resize event where the previous capacity == new capacity IMHO. Balbir Singh. > On 01/01/2020 11:54 PM, Balbir Singh wrote: > > block/genhd provides disk_set_capacity() for sending > > RESIZE notifications via uevents. This notification is > > newly added to NVME devices > > > > Signed-off-by: Balbir Singh <sblbir@amazon.com> > > --- > > 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 667f18f465be..cb214e914fc2 100644 > > --- a/drivers/nvme/host/core.c > > +++ b/drivers/nvme/host/core.c > > @@ -1808,7 +1808,7 @@ 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); > > > >
On Mon, Jan 06, 2020 at 12:46:26AM +0000, Singh, Balbir wrote: > On Sat, 2020-01-04 at 22:27 +0000, Chaitanya Kulkarni wrote: > > Quick question here if user executes nvme ns-rescan /dev/nvme1 > > will following code result in triggering uevent(s) for > > the namespace(s( for which there is no change in the size ? > > > > If so is that an expected behavior ? > > > > My old code had a check to see if old_capacity != new_capacity as well. > I can redo those bits if needed. > > The expected behaviour is not clear, but the functionality is not broken, user > space should be able to deal with a resize event where the previous capacity > == new capacity IMHO. I think it makes sense to not bother with a notification unless there is an actual change.
Christoph, >> The expected behaviour is not clear, but the functionality is not >> broken, user space should be able to deal with a resize event where >> the previous capacity == new capacity IMHO. > > I think it makes sense to not bother with a notification unless there > is an actual change. I agree.
On Wed, 2020-01-08 at 22:33 -0500, Martin K. Petersen wrote: > Christoph, > > > > The expected behaviour is not clear, but the functionality is not > > > broken, user space should be able to deal with a resize event where > > > the previous capacity == new capacity IMHO. > > > > I think it makes sense to not bother with a notification unless there > > is an actual change. > > I agree. > Yes, absolutely.
On Wed, 2020-01-08 at 16:04 +0100, hch@lst.de wrote: > On Mon, Jan 06, 2020 at 12:46:26AM +0000, Singh, Balbir wrote: > > On Sat, 2020-01-04 at 22:27 +0000, Chaitanya Kulkarni wrote: > > > Quick question here if user executes nvme ns-rescan /dev/nvme1 > > > will following code result in triggering uevent(s) for > > > the namespace(s( for which there is no change in the size ? > > > > > > If so is that an expected behavior ? > > > > > > > My old code had a check to see if old_capacity != new_capacity as well. > > I can redo those bits if needed. > > > > The expected behaviour is not clear, but the functionality is not broken, > > user > > space should be able to deal with a resize event where the previous > > capacity > > == new capacity IMHO. > > I think it makes sense to not bother with a notification unless there > is an actual change. [Sorry for the delayed response, just back from LCA] Agreed! Balbir Singh
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 667f18f465be..cb214e914fc2 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -1808,7 +1808,7 @@ 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);
block/genhd provides disk_set_capacity() for sending RESIZE notifications via uevents. This notification is newly added to NVME devices Signed-off-by: Balbir Singh <sblbir@amazon.com> --- drivers/nvme/host/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)