On Tue, Sep 28, 2021 at 09:19:47AM +0900, Tetsuo Handa wrote:
> On 2021/09/28 7:03, Luis Chamberlain wrote:
> > diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
> > index 5dc9b3d32415..be0627345b21 100644
> > --- a/drivers/block/ataflop.c
> > +++ b/drivers/block/ataflop.c
> > @@ -1989,24 +1989,34 @@ static int ataflop_alloc_disk(unsigned int drive, unsigned int type)
> >
> > static DEFINE_MUTEX(ataflop_probe_lock);
> >
> > -static void ataflop_probe(dev_t dev)
> > +static int ataflop_probe(dev_t dev)
> > {
> > int drive = MINOR(dev) & 3;
> > int type = MINOR(dev) >> 2;
> > + int err = 0;
> >
> > if (type)
> > type--;
> >
> > - if (drive >= FD_MAX_UNITS || type >= NUM_DISK_MINORS)
> > - return;
> > + if (drive >= FD_MAX_UNITS || type >= NUM_DISK_MINORS) {
> > + err = -EINVAL;
> > + goto out;
> > + }
> > +
> > mutex_lock(&ataflop_probe_lock);
> > if (!unit[drive].disk[type]) {
> > - if (ataflop_alloc_disk(drive, type) == 0) {
> > - add_disk(unit[drive].disk[type]);
> > + err = ataflop_alloc_disk(drive, type);
> > + if (err == 0) {
> > + err = add_disk(unit[drive].disk[type]);
> > + if (err)
> > + blk_cleanup_disk(unit[drive].disk[type]);
> > unit[drive].registered[type] = true;
>
> Why setting registered to true despite add_disk() failed?
> del_gendisk() without successful add_disk() sounds wrong.
That was a mistake, fixed.
> Don't we need to undo ataflop_alloc_disk() because it sets
> unit[drive].disk[type] to non-NULL ?
ataflop_alloc_disk() just calls blk_mq_alloc_disk() for its
allocation, and so blk_cleanup_disk() does that for us. Please
let me know if I missed anything.
> > diff --git a/drivers/block/brd.c b/drivers/block/brd.c
> > index c2bf4946f4e3..82a93044de95 100644
> > --- a/drivers/block/brd.c
> > +++ b/drivers/block/brd.c
> > @@ -426,10 +426,11 @@ static int brd_alloc(int i)
> > return err;
> > }
> >
> > -static void brd_probe(dev_t dev)
> > +static int brd_probe(dev_t dev)
> > {
> > int i = MINOR(dev) / max_part;
> > struct brd_device *brd;
> > + int err = 0;
> >
> > mutex_lock(&brd_devices_mutex);
> > list_for_each_entry(brd, &brd_devices, brd_list) {
> > @@ -437,9 +438,11 @@ static void brd_probe(dev_t dev)
> > goto out_unlock;
> > }
> >
> > - brd_alloc(i);
> > + err = brd_alloc(i);
> > out_unlock:
> > mutex_unlock(&brd_devices_mutex);
> > +
> > + return err;
> > }
> >
> > static void brd_del_one(struct brd_device *brd)
>
> https://lkml.kernel.org/r/e205f13d-18ff-a49c-0988-7de6ea5ff823@xxxxxxxxxxxxxxxxxxx
> will require this part to be updated.
Indeed, rebased, thanks for the heads up!
> > diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
> > index 0434f28742e7..95a1c8ef62f7 100644
> > --- a/drivers/block/floppy.c
> > +++ b/drivers/block/floppy.c
> > @@ -4517,21 +4517,27 @@ static int floppy_alloc_disk(unsigned int drive, unsigned int type)
> >
> > static DEFINE_MUTEX(floppy_probe_lock);
> >
> > -static void floppy_probe(dev_t dev)
> > +static int floppy_probe(dev_t dev)
> > {
> > unsigned int drive = (MINOR(dev) & 3) | ((MINOR(dev) & 0x80) >> 5);
> > unsigned int type = (MINOR(dev) >> 2) & 0x1f;
> > + int err = 0;
> >
> > if (drive >= N_DRIVE || !floppy_available(drive) ||
> > type >= ARRAY_SIZE(floppy_type))
> > - return;
> > + return -EINVAL;
> >
> > mutex_lock(&floppy_probe_lock);
> > if (!disks[drive][type]) {
> > - if (floppy_alloc_disk(drive, type) == 0)
> > - add_disk(disks[drive][type]);
> > + if (floppy_alloc_disk(drive, type) == 0) {
> > + err = add_disk(disks[drive][type]);
> > + if (err)
> > + blk_cleanup_disk(disks[drive][type]);
>
> This makes future floppy_probe() no-op once add_disk() failed (or maybe a bad
> thing happens somewhere else), for disks[drive][type] was set to non-NULL by
> floppy_alloc_disk() but blk_cleanup_disk() does not reset it to NULL.
Thanks!
I think just setting disks[drive][type] = NULL after the
blk_cleanup_disk() fixes that issue.
> According to floppy_module_exit() which tries to cleanup it, implementing
> undo might be complicated...
I can't see what would be missing from just setting disks[drive][type] = NULL.
Can you clarify?
Luis
