+static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
+{
+ int sect = 0; /* Offset from r10_bio->sector */
+ int sectors = r10_bio->sectors;
+ mdk_rdev_t*rdev;
+ int max_read_errors = atomic_read(&mddev->max_corr_read_errors);
+
+ rcu_read_lock();
+ {
+ int d = r10_bio->devs[r10_bio->read_slot].devnum;
+ char b[BDEVNAME_SIZE];
+ int cur_read_error_count = 0;
+
+ rdev = rcu_dereference(conf->mirrors[d].rdev);
+ bdevname(rdev->bdev, b);
+
+ if (test_bit(Faulty, &rdev->flags)) {
+ rcu_read_unlock();
+ /* drive has already been failed, just ignore any
+ more fix_read_error() attempts */
+ return;
+ }
+
+ check_decay_read_errors(mddev, rdev);
+ atomic_inc(&rdev->read_errors);
+ cur_read_error_count = atomic_read(&rdev->read_errors);
+ if (cur_read_error_count > max_read_errors) {
+ rcu_read_unlock();
+ printk(KERN_NOTICE
+ "raid10: %s: Raid device exceeded "
+ "read_error threshold "
+ "[cur %d:max %d]\n",
+ b, cur_read_error_count, max_read_errors);
+ printk(KERN_NOTICE
+ "raid10: %s: Failing raid "
+ "device\n", b);
+ md_error(mddev, conf->mirrors[d].rdev);
+ return;
+ }
+ }
+ rcu_read_unlock();
+
+ while(sectors) {
+ int s = sectors;
+ int sl = r10_bio->read_slot;
+ int success = 0;
+ int start;
+
+ if (s > (PAGE_SIZE>>9))
+ s = PAGE_SIZE >> 9;
+
+ rcu_read_lock();
+ do {
+ int d = r10_bio->devs[sl].devnum;
+ rdev = rcu_dereference(conf->mirrors[d].rdev);
+ if (rdev &&
+ test_bit(In_sync, &rdev->flags)) {
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+ success = sync_page_io(rdev->bdev,
+ r10_bio->devs[sl].addr +
+ sect + rdev->data_offset,
+ s<<9,
+ conf->tmppage, READ);
+ rdev_dec_pending(rdev, mddev);
+ rcu_read_lock();
+ if (success)
+ break;
+ }
+ sl++;
+ if (sl == conf->copies)
+ sl = 0;
+ } while (!success && sl != r10_bio->read_slot);
+ rcu_read_unlock();
+
+ if (!success) {
+ /* Cannot read from anywhere -- bye bye array */
+ int dn = r10_bio->devs[r10_bio->read_slot].devnum;
+ md_error(mddev, conf->mirrors[dn].rdev);
+ break;
+ }
+
+ start = sl;
+ /* write it back and re-read */
+ rcu_read_lock();
+ while (sl != r10_bio->read_slot) {
+ char b[BDEVNAME_SIZE];
+ int d;
+ if (sl==0)
+ sl = conf->copies;
+ sl--;
+ d = r10_bio->devs[sl].devnum;
+ rdev = rcu_dereference(conf->mirrors[d].rdev);
+ if (rdev &&
+ test_bit(In_sync, &rdev->flags)) {
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+ atomic_add(s, &rdev->corrected_errors);
+ if (sync_page_io(rdev->bdev,
+ r10_bio->devs[sl].addr +
+ sect + rdev->data_offset,
+ s<<9, conf->tmppage, WRITE)
+ == 0) {
+ /* Well, this device is dead */
+ printk(KERN_NOTICE
+ "raid10:%s: read correction "
+ "write failed"
+ " (%d sectors at %llu on %s)\n",
+ mdname(mddev), s,
+ (unsigned long long)(sect+
+ rdev->data_offset),
+ bdevname(rdev->bdev, b));
+ printk(KERN_NOTICE "raid10:%s: failing "
+ "drive\n",
+ bdevname(rdev->bdev, b));
+ md_error(mddev, rdev);
+ }
+ rdev_dec_pending(rdev, mddev);
+ rcu_read_lock();
+ }
+ }
+ sl = start;
+ while (sl != r10_bio->read_slot) {
+ int d;
+ if (sl==0)
+ sl = conf->copies;
+ sl--;
+ d = r10_bio->devs[sl].devnum;
+ rdev = rcu_dereference(conf->mirrors[d].rdev);
+ if (rdev &&
+ test_bit(In_sync, &rdev->flags)) {
+ char b[BDEVNAME_SIZE];
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+ if (sync_page_io(rdev->bdev,
+ r10_bio->devs[sl].addr +
+ sect + rdev->data_offset,
+ s<<9, conf->tmppage,
+ READ) == 0) {
+ /* Well, this device is dead */
+ printk(KERN_NOTICE
+ "raid10:%s: unable to read back "
+ "corrected sectors"
+ " (%d sectors at %llu on %s)\n",
+ mdname(mddev), s,
+ (unsigned long long)(sect+
+ rdev->data_offset),
+ bdevname(rdev->bdev, b));
+ printk(KERN_NOTICE "raid10:%s: failing drive\n",
+ bdevname(rdev->bdev, b));
+
+ md_error(mddev, rdev);
+ } else {
+ printk(KERN_INFO
+ "raid10:%s: read error corrected"
+ " (%d sectors at %llu on %s)\n",
+ mdname(mddev), s,
+ (unsigned long long)(sect+
+ rdev->data_offset),
+ bdevname(rdev->bdev, b));
+ }
+
+ rdev_dec_pending(rdev, mddev);
+ rcu_read_lock();
+ }
+ }
+ rcu_read_unlock();
+
+ sectors -= s;
+ sect += s;
+ }
+}
+