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

drivers/block/xen-blkfront.c

+39 −26
Original line number Diff line number Diff line
@@ -126,7 +126,6 @@ struct blkfront_info 
	unsigned int persistent_gnts_c;

	unsigned long shadow_free;

	unsigned int feature_flush;

	unsigned int flush_op;

	unsigned int feature_discard:1;

	unsigned int feature_secdiscard:1;

	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

				 * 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;

		}
@@ -582,12 +593,14 @@ 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,

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 +625,8 @@ 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;

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

{

	blk_queue_flush(info->rq, info->feature_flush);

	printk(KERN_INFO "blkfront: %s: %s: %s %s %s %s %s\n",

	       info->gd->disk_name,

	       info->flush_op == BLKIF_OP_WRITE_BARRIER ?

		"barrier" : (info->flush_op == BLKIF_OP_FLUSH_DISKCACHE ?

		"flush diskcache" : "barrier or flush"),

	       info->feature_flush ? "enabled;" : "disabled;",

	       "persistent grants:",

	       info->feature_persistent ? "enabled;" : "disabled;",

	       "indirect descriptors:",

	pr_info("blkfront: %s: %s %s %s %s %s\n",

		info->gd->disk_name, flush_info(info->feature_flush),

		"persistent grants:", info->feature_persistent ?

		"enabled;" : "disabled;", "indirect descriptors:",

		info->max_indirect_segments ? "enabled;" : "disabled;");

}
@@ -1188,7 +1207,6 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id) 
				if (error == -EOPNOTSUPP)

					error = 0;

				info->feature_flush = 0;

				info->flush_op = 0;

				xlvbd_flush(info);

			}

			/* fall through */
@@ -1808,7 +1826,6 @@ static void blkfront_connect(struct blkfront_info *info) 
		physical_sector_size = sector_size;



	info->feature_flush = 0;

	info->flush_op = 0;



	err = xenbus_gather(XBT_NIL, info->xbdev->otherend,

			    "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 (!err && barrier) {

	if (!err && barrier)

		info->feature_flush = REQ_FLUSH | REQ_FUA;

		info->flush_op = BLKIF_OP_WRITE_BARRIER;

	}

	/*

	 * And if there is "feature-flush-cache" use that above

	 * barriers.
@@ -1833,10 +1848,8 @@ static void blkfront_connect(struct blkfront_info *info) 
			    "feature-flush-cache", "%d", &flush,

			    NULL);



	if (!err && flush) {

	if (!err && flush)

		info->feature_flush = REQ_FLUSH;

		info->flush_op = BLKIF_OP_FLUSH_DISKCACHE;

	}



	err = xenbus_gather(XBT_NIL, info->xbdev->otherend,

			    "feature-discard", "%d", &discard,