1 files changed, 126 insertions, 53 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 4e04c79aa2c2..57d32555f191 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1930,7 +1930,7 @@ out_unlock:
 	return BLK_QC_T_NONE;
 }
 
-static void handle_bad_sector(struct bio *bio)
+static void handle_bad_sector(struct bio *bio, sector_t maxsector)
 {
 	char b[BDEVNAME_SIZE];
 
@@ -1938,7 +1938,7 @@ static void handle_bad_sector(struct bio *bio)
 	printk(KERN_INFO "%s: rw=%d, want=%Lu, limit=%Lu\n",
 			bio_devname(bio, b), bio->bi_opf,
 			(unsigned long long)bio_end_sector(bio),
-			(long long)get_capacity(bio->bi_disk));
+			(long long)maxsector);
 }
 
 #ifdef CONFIG_FAIL_MAKE_REQUEST
@@ -1976,67 +1976,74 @@ static inline bool should_fail_request(struct hd_struct *part,
 
 #endif /* CONFIG_FAIL_MAKE_REQUEST */
 
+static inline bool bio_check_ro(struct bio *bio, struct hd_struct *part)
+{
+	if (part->policy && op_is_write(bio_op(bio))) {
+		char b[BDEVNAME_SIZE];
+
+		printk(KERN_ERR
+		       "generic_make_request: Trying to write "
+			"to read-only block-device %s (partno %d)\n",
+			bio_devname(bio, b), part->partno);
+		return true;
+	}
+
+	return false;
+}
+
+/*
+ * Check whether this bio extends beyond the end of the device or partition.
+ * This may well happen - the kernel calls bread() without checking the size of
+ * the device, e.g., when mounting a file system.
+ */
+static inline int bio_check_eod(struct bio *bio, sector_t maxsector)
+{
+	unsigned int nr_sectors = bio_sectors(bio);
+
+	if (nr_sectors && maxsector &&
+	    (nr_sectors > maxsector ||
+	     bio->bi_iter.bi_sector > maxsector - nr_sectors)) {
+		handle_bad_sector(bio, maxsector);
+		return -EIO;
+	}
+	return 0;
+}
+
 /*
  * Remap block n of partition p to block n+start(p) of the disk.
  */
 static inline int blk_partition_remap(struct bio *bio)
 {
 	struct hd_struct *p;
-	int ret = 0;
+	int ret = -EIO;
+
+	rcu_read_lock();
+	p = __disk_get_part(bio->bi_disk, bio->bi_partno);
+	if (unlikely(!p))
+		goto out;
+	if (unlikely(should_fail_request(p, bio->bi_iter.bi_size)))
+		goto out;
+	if (unlikely(bio_check_ro(bio, p)))
+		goto out;
 
 	/*
 	 * Zone reset does not include bi_size so bio_sectors() is always 0.
 	 * Include a test for the reset op code and perform the remap if needed.
 	 */
-	if (!bio->bi_partno ||
-	    (!bio_sectors(bio) && bio_op(bio) != REQ_OP_ZONE_RESET))
-		return 0;
-
-	rcu_read_lock();
-	p = __disk_get_part(bio->bi_disk, bio->bi_partno);
-	if (likely(p && !should_fail_request(p, bio->bi_iter.bi_size))) {
+	if (bio_sectors(bio) || bio_op(bio) == REQ_OP_ZONE_RESET) {
+		if (bio_check_eod(bio, part_nr_sects_read(p)))
+			goto out;
 		bio->bi_iter.bi_sector += p->start_sect;
 		bio->bi_partno = 0;
 		trace_block_bio_remap(bio->bi_disk->queue, bio, part_devt(p),
-				bio->bi_iter.bi_sector - p->start_sect);
-	} else {
-		printk("%s: fail for partition %d\n", __func__, bio->bi_partno);
-		ret = -EIO;
+				      bio->bi_iter.bi_sector - p->start_sect);
 	}
+	ret = 0;
+out:
 	rcu_read_unlock();
-
 	return ret;
 }
 
-/*
- * Check whether this bio extends beyond the end of the device.
- */
-static inline int bio_check_eod(struct bio *bio, unsigned int nr_sectors)
-{
-	sector_t maxsector;
-
-	if (!nr_sectors)
-		return 0;
-
-	/* Test device or partition size, when known. */
-	maxsector = get_capacity(bio->bi_disk);
-	if (maxsector) {
-		sector_t sector = bio->bi_iter.bi_sector;
-
-		if (maxsector < nr_sectors || maxsector - nr_sectors < sector) {
-			/*
-			 * This may well happen - the kernel calls bread()
-			 * without checking the size of the device, e.g., when
-			 * mounting a device.
-			 */
-			handle_bad_sector(bio);
-			return 1;
-		}
-	}
-
-	return 0;
-}
-
 static noinline_for_stack bool
 generic_make_request_checks(struct bio *bio)
 {
@@ -2047,9 +2054,6 @@ generic_make_request_checks(struct bio *bio)
 
 	might_sleep();
 
-	if (bio_check_eod(bio, nr_sectors))
-		goto end_io;
-
 	q = bio->bi_disk->queue;
 	if (unlikely(!q)) {
 		printk(KERN_ERR
@@ -2063,18 +2067,21 @@ generic_make_request_checks(struct bio *bio)
 	 * For a REQ_NOWAIT based request, return -EOPNOTSUPP
 	 * if queue is not a request based queue.
 	 */
-
 	if ((bio->bi_opf & REQ_NOWAIT) && !queue_is_rq_based(q))
 		goto not_supported;
 
 	if (should_fail_request(&bio->bi_disk->part0, bio->bi_iter.bi_size))
 		goto end_io;
 
-	if (blk_partition_remap(bio))
-		goto end_io;
-
-	if (bio_check_eod(bio, nr_sectors))
-		goto end_io;
+	if (bio->bi_partno) {
+		if (unlikely(blk_partition_remap(bio)))
+			goto end_io;
+	} else {
+		if (unlikely(bio_check_ro(bio, &bio->bi_disk->part0)))
+			goto end_io;
+		if (unlikely(bio_check_eod(bio, get_capacity(bio->bi_disk))))
+			goto end_io;
+	}
 
 	/*
 	 * Filter flush bio's early so that make_request based
@@ -2259,6 +2266,40 @@ out:
 EXPORT_SYMBOL(generic_make_request);
 
 /**
+ * direct_make_request - hand a buffer directly to its device driver for I/O
+ * @bio:  The bio describing the location in memory and on the device.
+ *
+ * This function behaves like generic_make_request(), but does not protect
+ * against recursion.  Must only be used if the called driver is known
+ * to not call generic_make_request (or direct_make_request) again from
+ * its make_request function.  (Calling direct_make_request again from
+ * a workqueue is perfectly fine as that doesn't recurse).
+ */
+blk_qc_t direct_make_request(struct bio *bio)
+{
+	struct request_queue *q = bio->bi_disk->queue;
+	bool nowait = bio->bi_opf & REQ_NOWAIT;
+	blk_qc_t ret;
+
+	if (!generic_make_request_checks(bio))
+		return BLK_QC_T_NONE;
+
+	if (unlikely(blk_queue_enter(q, nowait))) {
+		if (nowait && !blk_queue_dying(q))
+			bio->bi_status = BLK_STS_AGAIN;
+		else
+			bio->bi_status = BLK_STS_IOERR;
+		bio_endio(bio);
+		return BLK_QC_T_NONE;
+	}
+
+	ret = q->make_request_fn(q, bio);
+	blk_queue_exit(q);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(direct_make_request);
+
+/**
  * submit_bio - submit a bio to the block device layer for I/O
  * @bio: The &struct bio which describes the I/O
  *
@@ -2302,6 +2343,17 @@ blk_qc_t submit_bio(struct bio *bio)
 }
 EXPORT_SYMBOL(submit_bio);
 
+bool blk_poll(struct request_queue *q, blk_qc_t cookie)
+{
+	if (!q->poll_fn || !blk_qc_t_valid(cookie))
+		return false;
+
+	if (current->plug)
+		blk_flush_plug_list(current->plug, false);
+	return q->poll_fn(q, cookie);
+}
+EXPORT_SYMBOL_GPL(blk_poll);
+
 /**
  * blk_cloned_rq_check_limits - Helper function to check a cloned request
  *                              for new the queue limits
@@ -2712,6 +2764,27 @@ struct request *blk_fetch_request(struct request_queue *q)
 }
 EXPORT_SYMBOL(blk_fetch_request);
 
+/*
+ * Steal bios from a request and add them to a bio list.
+ * The request must not have been partially completed before.
+ */
+void blk_steal_bios(struct bio_list *list, struct request *rq)
+{
+	if (rq->bio) {
+		if (list->tail)
+			list->tail->bi_next = rq->bio;
+		else
+			list->head = rq->bio;
+		list->tail = rq->biotail;
+
+		rq->bio = NULL;
+		rq->biotail = NULL;
+	}
+
+	rq->__data_len = 0;
+}
+EXPORT_SYMBOL_GPL(blk_steal_bios);
+
 /**
  * blk_update_request - Special helper function for request stacking drivers
  * @req:      the request being processed