block: Refuse request/bio merges with gaps in the integrity payload

If a driver sets the block queue virtual boundary mask, it means that
it cannot handle gaps so we must not allow those in the integrity
payload as well.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>

Fixed up by me to have duplicate integrity merge functions, depending
on whether block integrity is enabled or not. Fixes a compilations
issue with CONFIG_BLK_DEV_INTEGRITY unset.

Signed-off-by: Jens Axboe <axboe@fb.com>

3 files changed, 39 insertions, 0 deletions

diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index f548b64be092..75f29cf70188 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -204,6 +204,9 @@ bool blk_integrity_merge_rq(struct request_queue *q, struct request *req,
             q->limits.max_integrity_segments)
                 return false;
 
+        if (integrity_req_gap_back_merge(req, next->bio))
+                return false;
+
         return true;
 }
 EXPORT_SYMBOL(blk_integrity_merge_rq);
diff --git a/block/blk-merge.c b/block/blk-merge.c
index d9eddbc189f5..574ea7c0468f 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -440,6 +440,9 @@ int ll_back_merge_fn(struct request_queue *q, struct request *req,
 {
         if (req_gap_back_merge(req, bio))
                 return 0;
+        if (blk_integrity_rq(req) &&
+            integrity_req_gap_back_merge(req, bio))
+                return 0;
         if (blk_rq_sectors(req) + bio_sectors(bio) >
             blk_rq_get_max_sectors(req)) {
                 req->cmd_flags |= REQ_NOMERGE;
@@ -461,6 +464,9 @@ int ll_front_merge_fn(struct request_queue *q, struct request *req,
 
         if (req_gap_front_merge(req, bio))
                 return 0;
+        if (blk_integrity_rq(req) &&
+            integrity_req_gap_front_merge(req, bio))
+                return 0;
         if (blk_rq_sectors(req) + bio_sectors(bio) >
             blk_rq_get_max_sectors(req)) {
                 req->cmd_flags |= REQ_NOMERGE;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 2ff94def041e..1aac7316a4b5 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1514,6 +1514,26 @@ queue_max_integrity_segments(struct request_queue *q)
         return q->limits.max_integrity_segments;
 }
 
+static inline bool integrity_req_gap_back_merge(struct request *req,
+                                                struct bio *next)
+{
+        struct bio_integrity_payload *bip = bio_integrity(req->bio);
+        struct bio_integrity_payload *bip_next = bio_integrity(next);
+
+        return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
+                                bip_next->bip_vec[0].bv_offset);
+}
+
+static inline bool integrity_req_gap_front_merge(struct request *req,
+                                                 struct bio *bio)
+{
+        struct bio_integrity_payload *bip = bio_integrity(bio);
+        struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
+
+        return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
+                                bip_next->bip_vec[0].bv_offset);
+}
+
 #else /* CONFIG_BLK_DEV_INTEGRITY */
 
 struct bio;
@@ -1580,6 +1600,16 @@ static inline bool blk_integrity_is_initialized(struct gendisk *g)
 {
         return 0;
 }
+static inline bool integrity_req_gap_back_merge(struct request *req,
+                                                struct bio *next)
+{
+        return false;
+}
+static inline bool integrity_req_gap_front_merge(struct request *req,
+                                                 struct bio *bio)
+{
+        return false;
+}
 
 #endif /* CONFIG_BLK_DEV_INTEGRITY */