On 11/12/2020 15:57, SelvaKumar S wrote: [...] > +int blk_copy_emulate(struct block_device *bdev, struct blk_copy_payload *payload, > + gfp_t gfp_mask) > +{ > + struct request_queue *q = bdev_get_queue(bdev); > + struct bio *bio; > + void *buf = NULL; > + int i, nr_srcs, max_range_len, ret, cur_dest, cur_size; > + > + nr_srcs = payload->copy_range; > + max_range_len = q->limits.max_copy_range_sectors << SECTOR_SHIFT; > + cur_dest = payload->dest; > + buf = kvmalloc(max_range_len, GFP_ATOMIC); Why GFP_ATOMIC and not the passed in gfp_mask? Especially as this is a kvmalloc() which has the potential to grow quite big. > +int __blkdev_issue_copy(struct block_device *bdev, sector_t dest, > + sector_t nr_srcs, struct range_entry *rlist, gfp_t gfp_mask, > + int flags, struct bio **biop) > +{ [...] > + total_size = struct_size(payload, range, nr_srcs); > + payload = kmalloc(total_size, GFP_ATOMIC | __GFP_NOWARN); Same here. > diff --git a/block/ioctl.c b/block/ioctl.c > index 6b785181344f..a4a507d85e56 100644 > --- a/block/ioctl.c > +++ b/block/ioctl.c > @@ -142,6 +142,47 @@ static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode, > GFP_KERNEL, flags); > } > > +static int blk_ioctl_copy(struct block_device *bdev, fmode_t mode, > + unsigned long arg, unsigned long flags) > +{ [...] > + > + rlist = kmalloc_array(crange.nr_range, sizeof(*rlist), > + GFP_ATOMIC | __GFP_NOWARN); And here. I think this one can even be GFP_KERNEL.