Merge branch 'for-linus' of git://neil.brown.name/md

* 'for-linus' of git://neil.brown.name/md: (24 commits)
  md: clean up do_md_stop
  md: fix another deadlock with removing sysfs attributes.
  md: move revalidate_disk() back outside open_mutex
  md/raid10: fix deadlock with unaligned read during resync
  md/bitmap:  separate out loading a bitmap from initialising the structures.
  md/bitmap: prepare for storing write-intent-bitmap via dm-dirty-log.
  md/bitmap: optimise scanning of empty bitmaps.
  md/bitmap: clean up plugging calls.
  md/bitmap: reduce dependence on sysfs.
  md/bitmap: white space clean up and similar.
  md/raid5: export raid5 unplugging interface.
  md/plug: optionally use plugger to unplug an array during resync/recovery.
  md/raid5: add simple plugging infrastructure.
  md/raid5: export is_congested test
  raid5: Don't set read-ahead when there is no queue
  md: add support for raising dm events.
  md: export various start/stop interfaces
  md: split out md_rdev_init
  md: be more careful setting MD_CHANGE_CLEAN
  md/raid5: ensure we create a unique name for kmem_cache when mddev has no gendisk
  ...

1 files changed, 124 insertions, 0 deletions

diff --git a/lib/raid6/raid6test/test.c b/lib/raid6/raid6test/test.c
new file mode 100644
index 000000000000..7a930318b17d
--- /dev/null
+++ b/lib/raid6/raid6test/test.c
@@ -0,0 +1,124 @@
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright 2002-2007 H. Peter Anvin - All Rights Reserved
+ *
+ *   This file is part of the Linux kernel, and is made available under
+ *   the terms of the GNU General Public License version 2 or (at your
+ *   option) any later version; incorporated herein by reference.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * raid6test.c
+ *
+ * Test RAID-6 recovery with various algorithms
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <linux/raid/pq.h>
+
+#define NDISKS          16      /* Including P and Q */
+
+const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
+struct raid6_calls raid6_call;
+
+char *dataptrs[NDISKS];
+char data[NDISKS][PAGE_SIZE];
+char recovi[PAGE_SIZE], recovj[PAGE_SIZE];
+
+static void makedata(void)
+{
+        int i, j;
+
+        for (i = 0; i < NDISKS; i++) {
+                for (j = 0; j < PAGE_SIZE; j++)
+                        data[i][j] = rand();
+
+                dataptrs[i] = data[i];
+        }
+}
+
+static char disk_type(int d)
+{
+        switch (d) {
+        case NDISKS-2:
+                return 'P';
+        case NDISKS-1:
+                return 'Q';
+        default:
+                return 'D';
+        }
+}
+
+static int test_disks(int i, int j)
+{
+        int erra, errb;
+
+        memset(recovi, 0xf0, PAGE_SIZE);
+        memset(recovj, 0xba, PAGE_SIZE);
+
+        dataptrs[i] = recovi;
+        dataptrs[j] = recovj;
+
+        raid6_dual_recov(NDISKS, PAGE_SIZE, i, j, (void **)&dataptrs);
+
+        erra = memcmp(data[i], recovi, PAGE_SIZE);
+        errb = memcmp(data[j], recovj, PAGE_SIZE);
+
+        if (i < NDISKS-2 && j == NDISKS-1) {
+                /* We don't implement the DQ failure scenario, since it's
+                   equivalent to a RAID-5 failure (XOR, then recompute Q) */
+                erra = errb = 0;
+        } else {
+                printf("algo=%-8s  faila=%3d(%c)  failb=%3d(%c)  %s\n",
+                       raid6_call.name,
+                       i, disk_type(i),
+                       j, disk_type(j),
+                       (!erra && !errb) ? "OK" :
+                       !erra ? "ERRB" :
+                       !errb ? "ERRA" : "ERRAB");
+        }
+
+        dataptrs[i] = data[i];
+        dataptrs[j] = data[j];
+
+        return erra || errb;
+}
+
+int main(int argc, char *argv[])
+{
+        const struct raid6_calls *const *algo;
+        int i, j;
+        int err = 0;
+
+        makedata();
+
+        for (algo = raid6_algos; *algo; algo++) {
+                if (!(*algo)->valid || (*algo)->valid()) {
+                        raid6_call = **algo;
+
+                        /* Nuke syndromes */
+                        memset(data[NDISKS-2], 0xee, 2*PAGE_SIZE);
+
+                        /* Generate assumed good syndrome */
+                        raid6_call.gen_syndrome(NDISKS, PAGE_SIZE,
+                                                (void **)&dataptrs);
+
+                        for (i = 0; i < NDISKS-1; i++)
+                                for (j = i+1; j < NDISKS; j++)
+                                        err += test_disks(i, j);
+                }
+                printf("\n");
+        }
+
+        printf("\n");
+        /* Pick the best algorithm test */
+        raid6_select_algo();
+
+        if (err)
+                printf("\n*** ERRORS FOUND ***\n");
+
+        return err;
+}