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authorVitaly Kuznetsov <vkuznets@redhat.com>2014-12-01 14:01:13 +0100
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2014-12-10 12:20:07 -0500
commitad42d391ae388bd4ce4d53e8d7b4089cfdcba411 (patch)
tree3002687530aded859fba77ba63e5f7e1e73847fd /drivers/block/xen-blkfront.c
parent9af8785a38d4528d6675247f873b0f1ae29f3be8 (diff)
downloadlinux-ad42d391ae388bd4ce4d53e8d7b4089cfdcba411.tar.bz2
xen/blkfront: improve protection against issuing unsupported REQ_FUA
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> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/block/xen-blkfront.c')
-rw-r--r--drivers/block/xen-blkfront.c14
1 files changed, 8 insertions, 6 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 5ac312f6e0be..2e6c10371b24 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;
}