From eaccf49e9524dbdd43feb6a1cdafddf64252389a Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 15 Feb 2012 14:11:22 +0100 Subject: [PATCH] scsi-block: always use scsi_generic_ops for cache != none Signed-off-by: Paolo Bonzini --- hw/scsi-disk.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c index ec8e7cbffd..4101a59d34 100644 --- a/hw/scsi-disk.c +++ b/hw/scsi-disk.c @@ -1754,6 +1754,15 @@ static SCSIRequest *scsi_block_new_request(SCSIDevice *d, uint32_t tag, case WRITE_VERIFY_10: case WRITE_VERIFY_12: case WRITE_VERIFY_16: + /* If we are not using O_DIRECT, we might read stale data from the + * host cache if writes were made using other commands than these + * ones (such as WRITE SAME or EXTENDED COPY, etc.). So, without + * O_DIRECT everything must go through SG_IO. + */ + if (!(s->qdev.conf.bs->open_flags & BDRV_O_NOCACHE)) { + break; + } + /* MMC writing cannot be done via pread/pwrite, because it sometimes * involves writing beyond the maximum LBA or to negative LBA (lead-in). * And once you do these writes, reading from the block device is @@ -1764,10 +1773,11 @@ static SCSIRequest *scsi_block_new_request(SCSIDevice *d, uint32_t tag, * seen, but performance usually isn't paramount on optical media. So, * just make scsi-block operate the same as scsi-generic for them. */ - if (s->qdev.type != TYPE_ROM) { - return scsi_req_alloc(&scsi_disk_reqops, &s->qdev, tag, lun, - hba_private); - } + if (s->qdev.type == TYPE_ROM) { + break; + } + return scsi_req_alloc(&scsi_disk_reqops, &s->qdev, tag, lun, + hba_private); } return scsi_req_alloc(&scsi_generic_req_ops, &s->qdev, tag, lun, -- GitLab