[PATCH 6/9] device-mapper snapshot: barriers not supported

The snapshot and origin targets are incapable of handling barriers and 
need to indicate this.

Signed-Off-By: Alasdair G Kergon <[email protected]>

Index: linux-2.6.16-rc1/drivers/md/dm-snap.c
===================================================================
--- linux-2.6.16-rc1.orig/drivers/md/dm-snap.c
+++ linux-2.6.16-rc1/drivers/md/dm-snap.c
@@ -792,6 +792,9 @@ static int snapshot_map(struct dm_target
 	if (!s->valid)
 		return -EIO;
 
+	if (unlikely(bio_barrier(bio)))
+		return -EOPNOTSUPP;
+
 	/*
 	 * Write to snapshot - higher level takes care of RW/RO
 	 * flags so we should only get this if we are
@@ -1058,6 +1061,9 @@ static int origin_map(struct dm_target *
 	struct dm_dev *dev = (struct dm_dev *) ti->private;
 	bio->bi_bdev = dev->bdev;
 
+	if (unlikely(bio_barrier(bio)))
+		return -EOPNOTSUPP;
+
 	/* Only tell snapshots if this is a write */
 	return (bio_rw(bio) == WRITE) ? do_origin(dev, bio) : 1;
 }
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

---

• Follow-Ups:
  • Re: [PATCH 6/9] device-mapper snapshot: barriers not supported
    • From: Andrew Morton <[email protected]>

• Prev by Date: [PATCH 5/9] device-mapper disk statistics: timing
• Next by Date: [PATCH 7/9] device-mapper snapshot: fix origin_write pending_exception submission
• Previous by thread: [PATCH 5/9] device-mapper disk statistics: timing
• Next by thread: Re: [PATCH 6/9] device-mapper snapshot: barriers not supported
• Index(es):
  • Date
  • Thread

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]