1 files changed, 63 insertions, 25 deletions

diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 17753d80ad2..53e848c1093 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -5,12 +5,12 @@
  */
 
 #include "dm.h"
-
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/blkdev.h>
 #include <linux/bio.h>
 #include <linux/slab.h>
+#include <linux/device-mapper.h>
 
 #define DM_MSG_PREFIX "linear"
 
@@ -29,6 +29,7 @@ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 {
 	struct linear_c *lc;
 	unsigned long long tmp;
+	char dummy;
 
 	if (argc != 2) {
 		ti->error = "Invalid argument count";
@@ -41,18 +42,20 @@ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		return -ENOMEM;
 	}
 
-	if (sscanf(argv[1], "%llu", &tmp) != 1) {
+	if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1) {
 		ti->error = "dm-linear: Invalid device sector";
 		goto bad;
 	}
 	lc->start = tmp;
 
-	if (dm_get_device(ti, argv[0], lc->start, ti->len,
-			  dm_table_get_mode(ti->table), &lc->dev)) {
+	if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev)) {
 		ti->error = "dm-linear: Device lookup failed";
 		goto bad;
 	}
 
+	ti->num_flush_bios = 1;
+	ti->num_discard_bios = 1;
+	ti->num_write_same_bios = 1;
 	ti->private = lc;
 	return 0;
 
@@ -69,19 +72,32 @@ static void linear_dtr(struct dm_target *ti)
 	kfree(lc);
 }
 
-static int linear_map(struct dm_target *ti, struct bio *bio,
-		      union map_info *map_context)
+static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector)
 {
-	struct linear_c *lc = (struct linear_c *) ti->private;
+	struct linear_c *lc = ti->private;
+
+	return lc->start + dm_target_offset(ti, bi_sector);
+}
+
+static void linear_map_bio(struct dm_target *ti, struct bio *bio)
+{
+	struct linear_c *lc = ti->private;
 
 	bio->bi_bdev = lc->dev->bdev;
-	bio->bi_sector = lc->start + (bio->bi_sector - ti->begin);
+	if (bio_sectors(bio))
+		bio->bi_iter.bi_sector =
+			linear_map_sector(ti, bio->bi_iter.bi_sector);
+}
+
+static int linear_map(struct dm_target *ti, struct bio *bio)
+{
+	linear_map_bio(ti, bio);
 
 	return DM_MAPIO_REMAPPED;
 }
 
-static int linear_status(struct dm_target *ti, status_type_t type,
-			 char *result, unsigned int maxlen)
+static void linear_status(struct dm_target *ti, status_type_t type,
+			  unsigned status_flags, char *result, unsigned maxlen)
 {
 	struct linear_c *lc = (struct linear_c *) ti->private;
 
@@ -95,34 +111,59 @@ static int linear_status(struct dm_target *ti, status_type_t type,
 				(unsigned long long)lc->start);
 		break;
 	}
-	return 0;
 }
 
-static int linear_ioctl(struct dm_target *ti, struct inode *inode,
-			struct file *filp, unsigned int cmd,
+static int linear_ioctl(struct dm_target *ti, unsigned int cmd,
 			unsigned long arg)
 {
 	struct linear_c *lc = (struct linear_c *) ti->private;
-	struct block_device *bdev = lc->dev->bdev;
-	struct file fake_file = {};
-	struct dentry fake_dentry = {};
+	struct dm_dev *dev = lc->dev;
+	int r = 0;
+
+	/*
+	 * Only pass ioctls through if the device sizes match exactly.
+	 */
+	if (lc->start ||
+	    ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT)
+		r = scsi_verify_blk_ioctl(NULL, cmd);
 
-	fake_file.f_mode = lc->dev->mode;
-	fake_file.f_path.dentry = &fake_dentry;
-	fake_dentry.d_inode = bdev->bd_inode;
+	return r ? : __blkdev_driver_ioctl(dev->bdev, dev->mode, cmd, arg);
+}
+
+static int linear_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
+			struct bio_vec *biovec, int max_size)
+{
+	struct linear_c *lc = ti->private;
+	struct request_queue *q = bdev_get_queue(lc->dev->bdev);
 
-	return blkdev_driver_ioctl(bdev->bd_inode, &fake_file, bdev->bd_disk, cmd, arg);
+	if (!q->merge_bvec_fn)
+		return max_size;
+
+	bvm->bi_bdev = lc->dev->bdev;
+	bvm->bi_sector = linear_map_sector(ti, bvm->bi_sector);
+
+	return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
+}
+
+static int linear_iterate_devices(struct dm_target *ti,
+				  iterate_devices_callout_fn fn, void *data)
+{
+	struct linear_c *lc = ti->private;
+
+	return fn(ti, lc->dev, lc->start, ti->len, data);
 }
 
 static struct target_type linear_target = {
 	.name   = "linear",
-	.version= {1, 0, 2},
+	.version = {1, 2, 1},
 	.module = THIS_MODULE,
 	.ctr    = linear_ctr,
 	.dtr    = linear_dtr,
 	.map    = linear_map,
 	.status = linear_status,
 	.ioctl  = linear_ioctl,
+	.merge  = linear_merge,
+	.iterate_devices = linear_iterate_devices,
 };
 
 int __init dm_linear_init(void)
@@ -137,8 +178,5 @@ int __init dm_linear_init(void)
 
 void dm_linear_exit(void)
 {
-	int r = dm_unregister_target(&linear_target);
-
-	if (r < 0)
-		DMERR("unregister failed %d", r);
+	dm_unregister_target(&linear_target);
 }