block: Don't merge requests if integrity flags differ

We'd occasionally merge requests with conflicting integrity flags.
Introduce a merge helper which checks that the requests have compatible
integrity payloads.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

3 files changed, 39 insertions, 23 deletions

diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index 1c6ba442cd91..79ffb4855af0 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -186,37 +186,53 @@ int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
 }
 EXPORT_SYMBOL(blk_integrity_compare);
 
-int blk_integrity_merge_rq(struct request_queue *q, struct request *req,
-                           struct request *next)
+bool blk_integrity_merge_rq(struct request_queue *q, struct request *req,
+                            struct request *next)
 {
-        if (blk_integrity_rq(req) != blk_integrity_rq(next))
-                return -1;
+        if (blk_integrity_rq(req) == 0 && blk_integrity_rq(next) == 0)
+                return true;
+
+        if (blk_integrity_rq(req) == 0 || blk_integrity_rq(next) == 0)
+                return false;
+
+        if (bio_integrity(req->bio)->bip_flags !=
+            bio_integrity(next->bio)->bip_flags)
+                return false;
 
         if (req->nr_integrity_segments + next->nr_integrity_segments >
             q->limits.max_integrity_segments)
-                return -1;
+                return false;
 
-        return 0;
+        return true;
 }
 EXPORT_SYMBOL(blk_integrity_merge_rq);
 
-int blk_integrity_merge_bio(struct request_queue *q, struct request *req,
-                            struct bio *bio)
+bool blk_integrity_merge_bio(struct request_queue *q, struct request *req,
+                             struct bio *bio)
 {
         int nr_integrity_segs;
         struct bio *next = bio->bi_next;
 
+        if (blk_integrity_rq(req) == 0 && bio_integrity(bio) == NULL)
+                return true;
+
+        if (blk_integrity_rq(req) == 0 || bio_integrity(bio) == NULL)
+                return false;
+
+        if (bio_integrity(req->bio)->bip_flags != bio_integrity(bio)->bip_flags)
+                return false;
+
         bio->bi_next = NULL;
         nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
         bio->bi_next = next;
 
         if (req->nr_integrity_segments + nr_integrity_segs >
             q->limits.max_integrity_segments)
-                return -1;
+                return false;
 
         req->nr_integrity_segments += nr_integrity_segs;
 
-        return 0;
+        return true;
 }
 EXPORT_SYMBOL(blk_integrity_merge_bio);
 
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 77881798f793..f71bad35b4cc 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -313,7 +313,7 @@ static inline int ll_new_hw_segment(struct request_queue *q,
         if (req->nr_phys_segments + nr_phys_segs > queue_max_segments(q))
                 goto no_merge;
 
-        if (bio_integrity(bio) && blk_integrity_merge_bio(q, req, bio))
+        if (blk_integrity_merge_bio(q, req, bio) == false)
                 goto no_merge;
 
         /*
@@ -410,7 +410,7 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
         if (total_phys_segments > queue_max_segments(q))
                 return 0;
 
-        if (blk_integrity_rq(req) && blk_integrity_merge_rq(q, req, next))
+        if (blk_integrity_merge_rq(q, req, next) == false)
                 return 0;
 
         /* Merge is OK... */
@@ -590,7 +590,7 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
                 return false;
 
         /* only merge integrity protected bio into ditto rq */
-        if (bio_integrity(bio) != blk_integrity_rq(rq))
+        if (blk_integrity_merge_bio(rq->q, rq, bio) == false)
                 return false;
 
         /* must be using the same buffer */
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 773df190a4ee..038b40f84c7a 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1497,10 +1497,10 @@ extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
                                    struct scatterlist *);
 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
-extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
-                                  struct request *);
-extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
-                                   struct bio *);
+extern bool blk_integrity_merge_rq(struct request_queue *, struct request *,
+                                   struct request *);
+extern bool blk_integrity_merge_bio(struct request_queue *, struct request *,
+                                    struct bio *);
 
 static inline
 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
@@ -1580,15 +1580,15 @@ static inline unsigned short queue_max_integrity_segments(struct request_queue *
 {
         return 0;
 }
-static inline int blk_integrity_merge_rq(struct request_queue *rq,
-                                         struct request *r1,
-                                         struct request *r2)
+static inline bool blk_integrity_merge_rq(struct request_queue *rq,
+                                          struct request *r1,
+                                          struct request *r2)
 {
         return 0;
 }
-static inline int blk_integrity_merge_bio(struct request_queue *rq,
-                                          struct request *r,
-                                          struct bio *b)
+static inline bool blk_integrity_merge_bio(struct request_queue *rq,
+                                           struct request *r,
+                                           struct bio *b)
 {
         return 0;
 }