1 files changed, 123 insertions, 22 deletions

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index c2cb7b87b440..e2766d8251a1 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -18,6 +18,7 @@
  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/blkdev.h>
 #include <linux/seq_file.h>
@@ -804,7 +805,7 @@ static int make_request(struct request_queue *q, struct bio * bio)
         mdk_rdev_t *blocked_rdev;
 
         if (unlikely(bio_rw_flagged(bio, BIO_RW_BARRIER))) {
-                bio_endio(bio, -EOPNOTSUPP);
+                md_barrier_request(mddev, bio);
                 return 0;
         }
 
@@ -1155,13 +1156,17 @@ static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
 
                         disk_stack_limits(mddev->gendisk, rdev->bdev,
                                           rdev->data_offset << 9);
-                        /* as we don't honour merge_bvec_fn, we must never risk
-                         * violating it, so limit ->max_sector to one PAGE, as
-                         * a one page request is never in violation.
+                        /* as we don't honour merge_bvec_fn, we must
+                         * never risk violating it, so limit
+                         * ->max_segments to one lying with a single
+                         * page, as a one page request is never in
+                         * violation.
                          */
-                        if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
-                            queue_max_sectors(mddev->queue) > (PAGE_SIZE>>9))
-                                blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
+                        if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
+                                blk_queue_max_segments(mddev->queue, 1);
+                                blk_queue_segment_boundary(mddev->queue,
+                                                           PAGE_CACHE_SIZE - 1);
+                        }
 
                         p->head_position = 0;
                         rdev->raid_disk = mirror;
@@ -1432,6 +1437,43 @@ static void recovery_request_write(mddev_t *mddev, r10bio_t *r10_bio)
 
 
 /*
+ * Used by fix_read_error() to decay the per rdev read_errors.
+ * We halve the read error count for every hour that has elapsed
+ * since the last recorded read error.
+ *
+ */
+static void check_decay_read_errors(mddev_t *mddev, mdk_rdev_t *rdev)
+{
+        struct timespec cur_time_mon;
+        unsigned long hours_since_last;
+        unsigned int read_errors = atomic_read(&rdev->read_errors);
+
+        ktime_get_ts(&cur_time_mon);
+
+        if (rdev->last_read_error.tv_sec == 0 &&
+            rdev->last_read_error.tv_nsec == 0) {
+                /* first time we've seen a read error */
+                rdev->last_read_error = cur_time_mon;
+                return;
+        }
+
+        hours_since_last = (cur_time_mon.tv_sec -
+                            rdev->last_read_error.tv_sec) / 3600;
+
+        rdev->last_read_error = cur_time_mon;
+
+        /*
+         * if hours_since_last is > the number of bits in read_errors
+         * just set read errors to 0. We do this to avoid
+         * overflowing the shift of read_errors by hours_since_last.
+         */
+        if (hours_since_last >= 8 * sizeof(read_errors))
+                atomic_set(&rdev->read_errors, 0);
+        else
+                atomic_set(&rdev->read_errors, read_errors >> hours_since_last);
+}
+
+/*
  * This is a kernel thread which:
  *
  *      1.      Retries failed read operations on working mirrors.
@@ -1444,6 +1486,43 @@ 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;
@@ -1488,6 +1567,7 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
                 /* 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;
@@ -1503,9 +1583,21 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
                                                  r10_bio->devs[sl].addr +
                                                  sect + rdev->data_offset,
                                                  s<<9, conf->tmppage, WRITE)
-                                    == 0)
+                                    == 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();
                         }
@@ -1526,10 +1618,22 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
                                 if (sync_page_io(rdev->bdev,
                                                  r10_bio->devs[sl].addr +
                                                  sect + rdev->data_offset,
-                                                 s<<9, conf->tmppage, READ) == 0)
+                                                 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
+                                } else {
                                         printk(KERN_INFO
                                                "raid10:%s: read error corrected"
                                                " (%d sectors at %llu on %s)\n",
@@ -1537,6 +1641,7 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
                                                (unsigned long long)(sect+
                                                     rdev->data_offset),
                                                bdevname(rdev->bdev, b));
+                                }
 
                                 rdev_dec_pending(rdev, mddev);
                                 rcu_read_lock();
@@ -2155,12 +2260,14 @@ static int run(mddev_t *mddev)
                 disk_stack_limits(mddev->gendisk, rdev->bdev,
                                   rdev->data_offset << 9);
                 /* as we don't honour merge_bvec_fn, we must never risk
-                 * violating it, so limit ->max_sector to one PAGE, as
-                 * a one page request is never in violation.
+                 * violating it, so limit max_segments to 1 lying
+                 * within a single page.
                  */
-                if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
-                    queue_max_sectors(mddev->queue) > (PAGE_SIZE>>9))
-                        blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
+                if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
+                        blk_queue_max_segments(mddev->queue, 1);
+                        blk_queue_segment_boundary(mddev->queue,
+                                                   PAGE_CACHE_SIZE - 1);
+                }
 
                 disk->head_position = 0;
         }
@@ -2275,13 +2382,6 @@ static void raid10_quiesce(mddev_t *mddev, int state)
                 lower_barrier(conf);
                 break;
         }
-        if (mddev->thread) {
-                if (mddev->bitmap)
-                        mddev->thread->timeout = mddev->bitmap->daemon_sleep * HZ;
-                else
-                        mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
-                md_wakeup_thread(mddev->thread);
-        }
 }
 
 static struct mdk_personality raid10_personality =
@@ -2315,6 +2415,7 @@ static void raid_exit(void)
 module_init(raid_init);
 module_exit(raid_exit);
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD");
 MODULE_ALIAS("md-personality-9"); /* RAID10 */
 MODULE_ALIAS("md-raid10");
 MODULE_ALIAS("md-level-10");