Add FAILFAST support

[zfs.git] / include / sys / blkdev.h

diff --git a/include/sys/blkdev.h b/include/sys/blkdev.h
index b84f66a..7102890 100644 (file)
--- a/include/sys/blkdev.h
+++ b/include/sys/blkdev.h
@@ -202,6 +202,38 @@ struct req_iterator {
                bio_for_each_segment(bvl, _iter.bio, _iter.i)
 #endif /* HAVE_RQ_FOR_EACH_SEGMENT */
 
+static inline void
+bio_set_flags_failfast(struct block_device *bdev, int *flags)
+{
+#ifdef HAVE_BIO_RW_FAILFAST
+       /*
+        * Disable BIO_RW_FAILFAST_* for loopback devices because of
+        * the following incorrect BUG_ON() in loop_make_request().
+        * This support is also disabled for md devices because the
+        * test suite layers md devices on top of loopback devices.
+        * This may be removed when the loopback driver is fixed.
+        *
+        *   BUG_ON(!lo || (rw != READ && rw != WRITE));
+        */
+#ifdef CONFIG_BUG
+       if ((MAJOR(bdev->bd_dev) == LOOP_MAJOR) ||
+           (MAJOR(bdev->bd_dev) == MD_MAJOR))
+               return;
+
+#ifdef BLOCK_EXT_MAJOR
+       if (MAJOR(bdev->bd_dev) == BLOCK_EXT_MAJOR)
+               return;
+#endif /* BLOCK_EXT_MAJOR */
+#endif /* CONFIG_BUG */
+       *flags |=
+           ((1 << BIO_RW_FAILFAST_DEV) |
+            (1 << BIO_RW_FAILFAST_TRANSPORT) |
+            (1 << BIO_RW_FAILFAST_DRIVER));
+#else /* !HAVE_BIO_RW_FAILFAST */
+       *flags |= (1 << BIO_RW_FAILFAST);
+#endif /* HAVE_BIO_RW_FAILFAST */
+}
+
 #ifndef DISK_NAME_LEN
 #define DISK_NAME_LEN  32
 #endif /* DISK_NAME_LEN */