[PATCH] md: count corrected read errors per drive

Store this total in superblock (As appropriate), and make it available to
userspace via sysfs.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 26 insertions, 1 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 594d8c312e6a..32a4e2311e43 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1000,6 +1000,7 @@ static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
         }
         rdev->preferred_minor = 0xffff;
         rdev->data_offset = le64_to_cpu(sb->data_offset);
+        atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
 
         rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
         bmask = queue_hardsect_size(rdev->bdev->bd_disk->queue)-1;
@@ -1139,6 +1140,8 @@ static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
         else
                 sb->resync_offset = cpu_to_le64(0);
 
+        sb->cnt_corrected_read = atomic_read(&rdev->corrected_errors);
+
         if (mddev->bitmap && mddev->bitmap_file == NULL) {
                 sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_offset);
                 sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
@@ -1592,9 +1595,30 @@ super_show(mdk_rdev_t *rdev, char *page)
 }
 static struct rdev_sysfs_entry rdev_super = __ATTR_RO(super);
 
+static ssize_t
+errors_show(mdk_rdev_t *rdev, char *page)
+{
+        return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
+}
+
+static ssize_t
+errors_store(mdk_rdev_t *rdev, const char *buf, size_t len)
+{
+        char *e;
+        unsigned long n = simple_strtoul(buf, &e, 10);
+        if (*buf && (*e == 0 || *e == '\n')) {
+                atomic_set(&rdev->corrected_errors, n);
+                return len;
+        }
+        return -EINVAL;
+}
+static struct rdev_sysfs_entry rdev_errors =
+__ATTR(errors, 0644, errors_show, errors_store);
+
 static struct attribute *rdev_default_attrs[] = {
         &rdev_state.attr,
         &rdev_super.attr,
+        &rdev_errors.attr,
         NULL,
 };
 static ssize_t
@@ -1674,6 +1698,7 @@ static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_mi
         rdev->data_offset = 0;
         atomic_set(&rdev->nr_pending, 0);
         atomic_set(&rdev->read_errors, 0);
+        atomic_set(&rdev->corrected_errors, 0);
 
         size = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
         if (!size) {
@@ -4729,7 +4754,7 @@ static int set_ro(const char *val, struct kernel_param *kp)
         int num = simple_strtoul(val, &e, 10);
         if (*val && (*e == '\0' || *e == '\n')) {
                 start_readonly = num;
-                return 0;;
+                return 0;
         }
         return -EINVAL;
 }