On Thu, Sep 20, 2018 at 02:21:58PM +0300, Leon Romanovsky wrote: > From: Leon Romanovsky <leonro@xxxxxxxxxxxx> > > Prepare IB device name field to rename operation by ensuring that all > accesses to it are protected with lock and users don't see part of name. Oh dear, no, that isn't going to work, there is too much stuff using dev_name.. Did you read the comment on device_rename?? https://elixir.bootlin.com/linux/v4.19-rc4/source/drivers/base/core.c#L2715 > The protection is done with global device_lock because it is used in > allocation and deallocation phases. At this stage, this lock is not > busy and easily can be moved to be per-device, once it will be needed. > > Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx> > drivers/infiniband/core/device.c | 24 +++++++++++++++++++++++- > include/rdma/ib_verbs.h | 8 +++++++- > 2 files changed, 30 insertions(+), 2 deletions(-) > > diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c > index 5a680a88aa87..3270cde6d806 100644 > +++ b/drivers/infiniband/core/device.c > @@ -170,6 +170,14 @@ static struct ib_device *__ib_device_get_by_name(const char *name) > return NULL; > } > > +void ib_device_get_name(struct ib_device *ibdev, char *name) > +{ > + down_read(&lists_rwsem); > + strlcpy(name, ibdev->name, IB_DEVICE_NAME_MAX); > + up_read(&lists_rwsem); > +} > +EXPORT_SYMBOL(ib_device_get_name); I think we have to follow netdev and just rely on device_rename() being 'good enough'. Switch everything to use dev_name()/etc rather than try and do something like this so the responsibility is on the device core to keep this working, not us. Turns out I have a series for that for unrelated reasons.. > static int alloc_name(char *name) > { > unsigned long *inuse; > @@ -202,6 +210,21 @@ static int alloc_name(char *name) > return 0; > } > > +int ib_device_alloc_name(struct ib_device *ibdev, const char *pattern) > +{ > + int ret = 0; > + > + mutex_lock(&device_mutex); > + strlcpy(ibdev->name, pattern, IB_DEVICE_NAME_MAX); > + if (strchr(ibdev->name, '%')) > + ret = alloc_name(ibdev->name); > + > + mutex_unlock(&device_mutex); > + > + return ret; > +} > +EXPORT_SYMBOL(ib_device_alloc_name); Can't call alloc_name() without also adding to the list, this will allow duplicates. Jason
