| Message ID | 20191129134306.2738-3-pdurrant@amazon.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | allow xen-blkback to be cleanly unloaded | expand |
On Fri, Nov 29, 2019 at 01:43:06PM +0000, Paul Durrant wrote: > Add a module_exit() to perform the necessary clean-up. > > Signed-off-by: Paul Durrant <pdurrant@amazon.com> LGTM: Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> AFAICT we should make sure this is not committed before patch 1, or else you could unload a blkback module that's still in use? Thanks, Roger.
> -----Original Message----- > From: Roger Pau Monné <roger.pau@citrix.com> > Sent: 29 November 2019 15:00 > To: Durrant, Paul <pdurrant@amazon.com> > Cc: linux-block@vger.kernel.org; linux-kernel@vger.kernel.org; xen- > devel@lists.xenproject.org; Konrad Rzeszutek Wilk > <konrad.wilk@oracle.com>; Jens Axboe <axboe@kernel.dk> > Subject: Re: [PATCH v2 2/2] block/xen-blkback: allow module to be cleanly > unloaded > > On Fri, Nov 29, 2019 at 01:43:06PM +0000, Paul Durrant wrote: > > Add a module_exit() to perform the necessary clean-up. > > > > Signed-off-by: Paul Durrant <pdurrant@amazon.com> > > LGTM: > > Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> > Thanks. > AFAICT we should make sure this is not committed before patch 1, or > else you could unload a blkback module that's still in use? > Yes, that's correct. Paul
On Fri, Nov 29, 2019 at 03:02:37PM +0000, Durrant, Paul wrote: > > -----Original Message----- > > From: Roger Pau Monné <roger.pau@citrix.com> > > Sent: 29 November 2019 15:00 > > To: Durrant, Paul <pdurrant@amazon.com> > > Cc: linux-block@vger.kernel.org; linux-kernel@vger.kernel.org; xen- > > devel@lists.xenproject.org; Konrad Rzeszutek Wilk > > <konrad.wilk@oracle.com>; Jens Axboe <axboe@kernel.dk> > > Subject: Re: [PATCH v2 2/2] block/xen-blkback: allow module to be cleanly > > unloaded > > > > On Fri, Nov 29, 2019 at 01:43:06PM +0000, Paul Durrant wrote: > > > Add a module_exit() to perform the necessary clean-up. > > > > > > Signed-off-by: Paul Durrant <pdurrant@amazon.com> > > > > LGTM: > > > > Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> > > > > Thanks. > > > AFAICT we should make sure this is not committed before patch 1, or > > else you could unload a blkback module that's still in use? > > > > Yes, that's correct. Given this is a very small change, and not really block related I think it would be better for both patches to be committed from the Xen tree, if Jens, Juergen and Boris agree. Thanks, Roger.
On 29.11.19 16:07, Roger Pau Monné wrote: > On Fri, Nov 29, 2019 at 03:02:37PM +0000, Durrant, Paul wrote: >>> -----Original Message----- >>> From: Roger Pau Monné <roger.pau@citrix.com> >>> Sent: 29 November 2019 15:00 >>> To: Durrant, Paul <pdurrant@amazon.com> >>> Cc: linux-block@vger.kernel.org; linux-kernel@vger.kernel.org; xen- >>> devel@lists.xenproject.org; Konrad Rzeszutek Wilk >>> <konrad.wilk@oracle.com>; Jens Axboe <axboe@kernel.dk> >>> Subject: Re: [PATCH v2 2/2] block/xen-blkback: allow module to be cleanly >>> unloaded >>> >>> On Fri, Nov 29, 2019 at 01:43:06PM +0000, Paul Durrant wrote: >>>> Add a module_exit() to perform the necessary clean-up. >>>> >>>> Signed-off-by: Paul Durrant <pdurrant@amazon.com> >>> >>> LGTM: >>> >>> Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> >>> >> >> Thanks. >> >>> AFAICT we should make sure this is not committed before patch 1, or >>> else you could unload a blkback module that's still in use? >>> >> >> Yes, that's correct. > > Given this is a very small change, and not really block related I > think it would be better for both patches to be committed from the Xen > tree, if Jens, Juergen and Boris agree. I'm fine with that. And: Reviewed-by: Juergen Gross <jgross@suse.com> Juergen
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index fd1e19f1a49f..e562a7e20c3c 100644 --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -1504,5 +1504,13 @@ static int __init xen_blkif_init(void) module_init(xen_blkif_init); +static void __exit xen_blkif_fini(void) +{ + xen_blkif_xenbus_fini(); + xen_blkif_interface_fini(); +} + +module_exit(xen_blkif_fini); + MODULE_LICENSE("Dual BSD/GPL"); MODULE_ALIAS("xen-backend:vbd"); diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h index 1d3002d773f7..49132b0adbbe 100644 --- a/drivers/block/xen-blkback/common.h +++ b/drivers/block/xen-blkback/common.h @@ -375,9 +375,12 @@ struct phys_req { struct block_device *bdev; blkif_sector_t sector_number; }; + int xen_blkif_interface_init(void); +void xen_blkif_interface_fini(void); int xen_blkif_xenbus_init(void); +void xen_blkif_xenbus_fini(void); irqreturn_t xen_blkif_be_int(int irq, void *dev_id); int xen_blkif_schedule(void *arg); diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index b90dbcd99c03..e8c5c54e1d26 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -333,6 +333,12 @@ int __init xen_blkif_interface_init(void) return 0; } +void xen_blkif_interface_fini(void) +{ + kmem_cache_destroy(xen_blkif_cachep); + xen_blkif_cachep = NULL; +} + /* * sysfs interface for VBD I/O requests */ @@ -1122,3 +1128,8 @@ int xen_blkif_xenbus_init(void) { return xenbus_register_backend(&xen_blkbk_driver); } + +void xen_blkif_xenbus_fini(void) +{ + xenbus_unregister_driver(&xen_blkbk_driver); +}
Add a module_exit() to perform the necessary clean-up. Signed-off-by: Paul Durrant <pdurrant@amazon.com> --- Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: "Roger Pau Monné" <roger.pau@citrix.com> Cc: Jens Axboe <axboe@kernel.dk> v2: - Drop the addition of ad-hoc reference counting as this is now done centrally in xenbus --- drivers/block/xen-blkback/blkback.c | 8 ++++++++ drivers/block/xen-blkback/common.h | 3 +++ drivers/block/xen-blkback/xenbus.c | 11 +++++++++++ 3 files changed, 22 insertions(+)