Messages in this thread | | | Date | Tue, 4 Apr 2017 13:55:09 +0900 | From | Sergey Senozhatsky <> | Subject | Re: [PATCH 1/5] zram: handle multiple pages attached bio's bvec |
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On (04/03/17 14:17), Minchan Kim wrote: > Johannes Thumshirn reported system goes the panic when using NVMe over > Fabrics loopback target with zram. > > The reason is zram expects each bvec in bio contains a single page > but nvme can attach a huge bulk of pages attached to the bio's bvec > so that zram's index arithmetic could be wrong so that out-of-bound > access makes panic. > > It can be solved by limiting max_sectors with SECTORS_PER_PAGE like > [1] but it makes zram slow because bio should split with each pages > so this patch makes zram aware of multiple pages in a bvec so it > could solve without any regression. > > [1] 0bc315381fe9, zram: set physical queue limits to avoid array out of > bounds accesses > > Cc: Jens Axboe <axboe@kernel.dk> > Cc: Hannes Reinecke <hare@suse.com> > Reported-by: Johannes Thumshirn <jthumshirn@suse.de> > Tested-by: Johannes Thumshirn <jthumshirn@suse.de> > Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> > Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> > Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
> + unsigned int remained = bvec.bv_len; ... > + } while (remained);
a tiny nitpick, "-ed" in variable name looks a bit unusual.
-ss
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