On 2020-06-19 13:47, Luis Chamberlain wrote: > Be pedantic on removal as well and hold the mutex. > This should prevent uses of addition while we exit. > > Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx> > Reviewed-by: Christoph Hellwig <hch@xxxxxx> > Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx> > --- > drivers/block/loop.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/block/loop.c b/drivers/block/loop.c > index c33bbbfd1bd9..d55e1b52f076 100644 > --- a/drivers/block/loop.c > +++ b/drivers/block/loop.c > @@ -2402,6 +2402,8 @@ static void __exit loop_exit(void) > > range = max_loop ? max_loop << part_shift : 1UL << MINORBITS; > > + mutex_lock(&loop_ctl_mutex); > + > idr_for_each(&loop_index_idr, &loop_exit_cb, NULL); > idr_destroy(&loop_index_idr); > > @@ -2409,6 +2411,8 @@ static void __exit loop_exit(void) > unregister_blkdev(LOOP_MAJOR, "loop"); > > misc_deregister(&loop_misc); > + > + mutex_unlock(&loop_ctl_mutex); > } > > module_init(loop_init); Is try_module_get(fops->owner) called before a loop device is opened and is module_put(fops->owner) called after a loop device is closed? Does that mean that it is impossible to unload the loop driver while a loop device is open? Does that mean that the above patch is not necessary or did I perhaps miss something? Thanks, Bart.
