Messages in this thread | | | Date | Wed, 03 Dec 2014 11:57:32 -0500 | From | Boris Ostrovsky <> | Subject | Re: [PATCH RESEND] xen/blkfront: improve protection against issuing unsupported REQ_FUA |
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On 12/01/2014 08:01 AM, Vitaly Kuznetsov wrote: > Guard against issuing unsupported REQ_FUA and REQ_FLUSH was introduced > in d11e61583 and was factored out into blkif_request_flush_valid() in > 0f1ca65ee. However: > 1) This check in incomplete. In case we negotiated to feature_flush = REQ_FLUSH > and flush_op = BLKIF_OP_FLUSH_DISKCACHE (so FUA is unsupported) FUA request > will still pass the check. > 2) blkif_request_flush_valid() is misnamed. It is bool but returns true when > the request is invalid. > 3) When blkif_request_flush_valid() fails -EIO is being returned. It seems that > -EOPNOTSUPP is more appropriate here. > Fix all of the above issues. > > This patch is based on the original patch by Laszlo Ersek and a comment by > Jeff Moyer. > > Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> > Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
(although, as I mentioned last time, a companion patch to remove flush_op would be a good thing to have)
-boris
> --- > drivers/block/xen-blkfront.c | 14 ++++++++------ > 1 file changed, 8 insertions(+), 6 deletions(-) > > diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c > index 5ac312f..2e6c103 100644 > --- a/drivers/block/xen-blkfront.c > +++ b/drivers/block/xen-blkfront.c > @@ -582,12 +582,14 @@ static inline void flush_requests(struct blkfront_info *info) > notify_remote_via_irq(info->irq); > } > > -static inline bool blkif_request_flush_valid(struct request *req, > - struct blkfront_info *info) > +static inline bool blkif_request_flush_invalid(struct request *req, > + struct blkfront_info *info) > { > return ((req->cmd_type != REQ_TYPE_FS) || > - ((req->cmd_flags & (REQ_FLUSH | REQ_FUA)) && > - !info->flush_op)); > + ((req->cmd_flags & REQ_FLUSH) && > + !(info->feature_flush & REQ_FLUSH)) || > + ((req->cmd_flags & REQ_FUA) && > + !(info->feature_flush & REQ_FUA))); > } > > /* > @@ -612,8 +614,8 @@ static void do_blkif_request(struct request_queue *rq) > > blk_start_request(req); > > - if (blkif_request_flush_valid(req, info)) { > - __blk_end_request_all(req, -EIO); > + if (blkif_request_flush_invalid(req, info)) { > + __blk_end_request_all(req, -EOPNOTSUPP); > continue; > } >
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