Commit ad42d391 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Konrad Rzeszutek Wilk

xen/blkfront: improve protection against issuing unsupported REQ_FUA

Guard against issuing unsupported REQ_FUA and REQ_FLUSH was introduced
in d11e6158 and was factored out into blkif_request_flush_valid() in
0f1ca65e. 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: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: default avatarLaszlo Ersek <lersek@redhat.com>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 9af8785a
......@@ -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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