[PATCH 4.16 03/43] blkdev_report_zones_ioctl(): Use vmalloc() to allocate large buffers

Greg Kroah-Hartman
2018-06-14T14:08:46Z

From: Bart Van Assche <bart.vanassche@wdc.com>

commit 327ea4adcfa37194739f1ec7c70568944d292281 upstream.

Avoid that complaints similar to the following appear in the kernel log
if the number of zones is sufficiently large:

fio: page allocation failure: order:9, mode:0x140c0c0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), nodemask=(null)
Call Trace:
dump_stack+0x63/0x88
warn_alloc+0xf5/0x190
__alloc_pages_slowpath+0x8f0/0xb0d
__alloc_pages_nodemask+0x242/0x260
alloc_pages_current+0x6a/0xb0
kmalloc_order+0x18/0x50
kmalloc_order_trace+0x26/0xb0
__kmalloc+0x20e/0x220
blkdev_report_zones_ioctl+0xa5/0x1a0
blkdev_ioctl+0x1ba/0x930
block_ioctl+0x41/0x50
do_vfs_ioctl+0xaa/0x610
SyS_ioctl+0x79/0x90
do_syscall_64+0x79/0x1b0
entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Fixes: 3ed05a987e0f ("blk-zoned: implement ioctls")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Shaun Tancheff <shaun.tancheff@seagate.com>
Cc: Damien Le Moal <damien.lemoal@hgst.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
block/blk-zoned.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -328,7 +328,11 @@ int blkdev_report_zones_ioctl(struct blo
if (!rep.nr_zones)
return -EINVAL;

- zones = kcalloc(rep.nr_zones, sizeof(struct blk_zone), GFP_KERNEL);
+ if (rep.nr_zones > INT_MAX / sizeof(struct blk_zone))
+ return -ERANGE;
+
+ zones = kvmalloc(rep.nr_zones * sizeof(struct blk_zone),
+ GFP_KERNEL | __GFP_ZERO);
if (!zones)
return -ENOMEM;

@@ -350,7 +354,7 @@ int blkdev_report_zones_ioctl(struct blo
}

out:
- kfree(zones);
+ kvfree(zones);

return ret;
}