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Commit d8ead9b7 authored by Jens Axboe's avatar Jens Axboe
Browse files

Merge branch 'for-jens-3.19' of...

Merge branch 'for-jens-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-3.19/drivers

Konrad writes:

These are two fixes for Xen blkfront. They harden how it deals with
broken backends.
parents 97fe3832 fdf9b965
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+39 −26
Original line number Original line Diff line number Diff line
@@ -126,7 +126,6 @@ struct blkfront_info
	unsigned int persistent_gnts_c;
	unsigned int persistent_gnts_c;
	unsigned long shadow_free;
	unsigned long shadow_free;
	unsigned int feature_flush;
	unsigned int feature_flush;
	unsigned int flush_op;
	unsigned int feature_discard:1;
	unsigned int feature_discard:1;
	unsigned int feature_secdiscard:1;
	unsigned int feature_secdiscard:1;
	unsigned int discard_granularity;
	unsigned int discard_granularity;
@@ -479,7 +478,19 @@ static int blkif_queue_request(struct request *req)
				 * way.  (It's also a FLUSH+FUA, since it is
				 * way.  (It's also a FLUSH+FUA, since it is
				 * guaranteed ordered WRT previous writes.)
				 * guaranteed ordered WRT previous writes.)
				 */
				 */
				ring_req->operation = info->flush_op;
				switch (info->feature_flush &
					((REQ_FLUSH|REQ_FUA))) {
				case REQ_FLUSH|REQ_FUA:
					ring_req->operation =
						BLKIF_OP_WRITE_BARRIER;
					break;
				case REQ_FLUSH:
					ring_req->operation =
						BLKIF_OP_FLUSH_DISKCACHE;
					break;
				default:
					ring_req->operation = 0;
				}
			}
			}
			ring_req->u.rw.nr_segments = nseg;
			ring_req->u.rw.nr_segments = nseg;
		}
		}
@@ -582,12 +593,14 @@ static inline void flush_requests(struct blkfront_info *info)
		notify_remote_via_irq(info->irq);
		notify_remote_via_irq(info->irq);
}
}


static inline bool blkif_request_flush_valid(struct request *req,
static inline bool blkif_request_flush_invalid(struct request *req,
					       struct blkfront_info *info)
					       struct blkfront_info *info)
{
{
	return ((req->cmd_type != REQ_TYPE_FS) ||
	return ((req->cmd_type != REQ_TYPE_FS) ||
		((req->cmd_flags & (REQ_FLUSH | REQ_FUA)) &&
		((req->cmd_flags & REQ_FLUSH) &&
		!info->flush_op));
		 !(info->feature_flush & REQ_FLUSH)) ||
		((req->cmd_flags & REQ_FUA) &&
		 !(info->feature_flush & REQ_FUA)));
}
}


/*
/*
@@ -612,8 +625,8 @@ static void do_blkif_request(struct request_queue *rq)


		blk_start_request(req);
		blk_start_request(req);


		if (blkif_request_flush_valid(req, info)) {
		if (blkif_request_flush_invalid(req, info)) {
			__blk_end_request_all(req, -EIO);
			__blk_end_request_all(req, -EOPNOTSUPP);
			continue;
			continue;
		}
		}


@@ -683,19 +696,25 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
	return 0;
	return 0;
}
}


static const char *flush_info(unsigned int feature_flush)
{
	switch (feature_flush & ((REQ_FLUSH | REQ_FUA))) {
	case REQ_FLUSH|REQ_FUA:
		return "barrier: enabled;";
	case REQ_FLUSH:
		return "flush diskcache: enabled;";
	default:
		return "barrier or flush: disabled;";
	}
}


static void xlvbd_flush(struct blkfront_info *info)
static void xlvbd_flush(struct blkfront_info *info)
{
{
	blk_queue_flush(info->rq, info->feature_flush);
	blk_queue_flush(info->rq, info->feature_flush);
	printk(KERN_INFO "blkfront: %s: %s: %s %s %s %s %s\n",
	pr_info("blkfront: %s: %s %s %s %s %s\n",
	       info->gd->disk_name,
		info->gd->disk_name, flush_info(info->feature_flush),
	       info->flush_op == BLKIF_OP_WRITE_BARRIER ?
		"persistent grants:", info->feature_persistent ?
		"barrier" : (info->flush_op == BLKIF_OP_FLUSH_DISKCACHE ?
		"enabled;" : "disabled;", "indirect descriptors:",
		"flush diskcache" : "barrier or flush"),
	       info->feature_flush ? "enabled;" : "disabled;",
	       "persistent grants:",
	       info->feature_persistent ? "enabled;" : "disabled;",
	       "indirect descriptors:",
		info->max_indirect_segments ? "enabled;" : "disabled;");
		info->max_indirect_segments ? "enabled;" : "disabled;");
}
}


@@ -1188,7 +1207,6 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
				if (error == -EOPNOTSUPP)
				if (error == -EOPNOTSUPP)
					error = 0;
					error = 0;
				info->feature_flush = 0;
				info->feature_flush = 0;
				info->flush_op = 0;
				xlvbd_flush(info);
				xlvbd_flush(info);
			}
			}
			/* fall through */
			/* fall through */
@@ -1808,7 +1826,6 @@ static void blkfront_connect(struct blkfront_info *info)
		physical_sector_size = sector_size;
		physical_sector_size = sector_size;


	info->feature_flush = 0;
	info->feature_flush = 0;
	info->flush_op = 0;


	err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
	err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
			    "feature-barrier", "%d", &barrier,
			    "feature-barrier", "%d", &barrier,
@@ -1821,10 +1838,8 @@ static void blkfront_connect(struct blkfront_info *info)
	 *
	 *
	 * If there are barriers, then we use flush.
	 * If there are barriers, then we use flush.
	 */
	 */
	if (!err && barrier) {
	if (!err && barrier)
		info->feature_flush = REQ_FLUSH | REQ_FUA;
		info->feature_flush = REQ_FLUSH | REQ_FUA;
		info->flush_op = BLKIF_OP_WRITE_BARRIER;
	}
	/*
	/*
	 * And if there is "feature-flush-cache" use that above
	 * And if there is "feature-flush-cache" use that above
	 * barriers.
	 * barriers.
@@ -1833,10 +1848,8 @@ static void blkfront_connect(struct blkfront_info *info)
			    "feature-flush-cache", "%d", &flush,
			    "feature-flush-cache", "%d", &flush,
			    NULL);
			    NULL);


	if (!err && flush) {
	if (!err && flush)
		info->feature_flush = REQ_FLUSH;
		info->feature_flush = REQ_FLUSH;
		info->flush_op = BLKIF_OP_FLUSH_DISKCACHE;
	}


	err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
	err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
			    "feature-discard", "%d", &discard,
			    "feature-discard", "%d", &discard,