> From: Christoph Hellwig [mailto:hch@xxxxxx] > Sent: Friday, January 13, 2017 02:19 > To: Dexuan Cui <decui@xxxxxxxxxxxxx> > Cc: linux-block@xxxxxxxxxxxxxxx; KY Srinivasan <kys@xxxxxxxxxxxxx>; Chris > Valean (Cloudbase Solutions SRL) <v-chvale@xxxxxxxxxxxxx> > Subject: Re: [Regression] fstrim hangs on Hyper-V: caused by "block: improve > handling of the magic discard payload" > > Next try: (I've also dropped most of the Cc list) > > diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c > index c35b6de..2f358f7 100644 > --- a/drivers/scsi/scsi_lib.c > +++ b/drivers/scsi/scsi_lib.c > @@ -1018,7 +1018,10 @@ static int scsi_init_sgtable(struct request *req, > struct scsi_data_buffer *sdb) > count = blk_rq_map_sg(req->q, req, sdb->table.sgl); > BUG_ON(count > sdb->table.nents); > sdb->table.nents = count; > - sdb->length = blk_rq_bytes(req); > + if (req->rq_flags & RQF_SPECIAL_PAYLOAD) > + sdb->length = req->special_vec.bv_len; > + else > + sdb->length = blk_rq_bytes(req); > return BLKPREP_OK; > } Hi Christoph, The patch works like a charm! fstrim can work now. Chris may help to do more test. FWIW: If (req->rq_flags & RQF_SPECIAL_PAYLOAD) is true, req->special_vec.bv_len is always 24 in my test. Thanks really a lot for your quick patch! :-) Can the patch make it into v4.10? IMO It's a really important fix. Thanks, -- Dexuan -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
