Merge branch 'mymd/for-next' into mymd/for-linus
authorShaohua Li <shli@fb.com>
Thu, 28 Jul 2016 16:34:14 +0000 (09:34 -0700)
committerShaohua Li <shli@fb.com>
Thu, 28 Jul 2016 16:34:14 +0000 (09:34 -0700)
drivers/md/md.c
drivers/md/md.h
drivers/md/multipath.c
drivers/md/raid1.c
drivers/md/raid10.c
drivers/md/raid10.h
drivers/md/raid5.c

index 1f123f5..2c3ab6f 100644 (file)
@@ -2482,8 +2482,7 @@ static int add_bound_rdev(struct md_rdev *rdev)
                if (add_journal)
                        mddev_resume(mddev);
                if (err) {
-                       unbind_rdev_from_array(rdev);
-                       export_rdev(rdev);
+                       md_kick_rdev_from_array(rdev);
                        return err;
                }
        }
@@ -2600,6 +2599,10 @@ state_store(struct md_rdev *rdev, const char *buf, size_t len)
                else
                        err = -EBUSY;
        } else if (cmd_match(buf, "remove")) {
+               if (rdev->mddev->pers) {
+                       clear_bit(Blocked, &rdev->flags);
+                       remove_and_add_spares(rdev->mddev, rdev);
+               }
                if (rdev->raid_disk >= 0)
                        err = -EBUSY;
                else {
@@ -3176,8 +3179,7 @@ int md_rdev_init(struct md_rdev *rdev)
        rdev->data_offset = 0;
        rdev->new_data_offset = 0;
        rdev->sb_events = 0;
-       rdev->last_read_error.tv_sec  = 0;
-       rdev->last_read_error.tv_nsec = 0;
+       rdev->last_read_error = 0;
        rdev->sb_loaded = 0;
        rdev->bb_page = NULL;
        atomic_set(&rdev->nr_pending, 0);
@@ -3583,6 +3585,8 @@ level_store(struct mddev *mddev, const char *buf, size_t len)
                        mddev->to_remove = &md_redundancy_group;
        }
 
+       module_put(oldpers->owner);
+
        rdev_for_each(rdev, mddev) {
                if (rdev->raid_disk < 0)
                        continue;
@@ -3940,6 +3944,8 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
                        } else
                                err = -EBUSY;
                }
+               if (!err)
+                       sysfs_notify_dirent_safe(mddev->sysfs_state);
                spin_unlock(&mddev->lock);
                return err ?: len;
        }
@@ -4191,7 +4197,8 @@ size_store(struct mddev *mddev, const char *buf, size_t len)
                return err;
        if (mddev->pers) {
                err = update_size(mddev, sectors);
-               md_update_sb(mddev, 1);
+               if (err == 0)
+                       md_update_sb(mddev, 1);
        } else {
                if (mddev->dev_sectors == 0 ||
                    mddev->dev_sectors > sectors)
@@ -7813,6 +7820,7 @@ void md_do_sync(struct md_thread *thread)
                if (ret)
                        goto skip;
 
+               set_bit(MD_CLUSTER_RESYNC_LOCKED, &mddev->flags);
                if (!(test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
                        test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) ||
                        test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
@@ -8151,18 +8159,11 @@ void md_do_sync(struct md_thread *thread)
                }
        }
  skip:
-       if (mddev_is_clustered(mddev) &&
-           ret == 0) {
-               /* set CHANGE_PENDING here since maybe another
-                * update is needed, so other nodes are informed */
-               set_mask_bits(&mddev->flags, 0,
-                             BIT(MD_CHANGE_PENDING) | BIT(MD_CHANGE_DEVS));
-               md_wakeup_thread(mddev->thread);
-               wait_event(mddev->sb_wait,
-                          !test_bit(MD_CHANGE_PENDING, &mddev->flags));
-               md_cluster_ops->resync_finish(mddev);
-       } else
-               set_bit(MD_CHANGE_DEVS, &mddev->flags);
+       /* set CHANGE_PENDING here since maybe another update is needed,
+        * so other nodes are informed. It should be harmless for normal
+        * raid */
+       set_mask_bits(&mddev->flags, 0,
+                     BIT(MD_CHANGE_PENDING) | BIT(MD_CHANGE_DEVS));
 
        spin_lock(&mddev->lock);
        if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
@@ -8188,15 +8189,34 @@ static int remove_and_add_spares(struct mddev *mddev,
        struct md_rdev *rdev;
        int spares = 0;
        int removed = 0;
+       bool remove_some = false;
 
-       rdev_for_each(rdev, mddev)
+       rdev_for_each(rdev, mddev) {
+               if ((this == NULL || rdev == this) &&
+                   rdev->raid_disk >= 0 &&
+                   !test_bit(Blocked, &rdev->flags) &&
+                   test_bit(Faulty, &rdev->flags) &&
+                   atomic_read(&rdev->nr_pending)==0) {
+                       /* Faulty non-Blocked devices with nr_pending == 0
+                        * never get nr_pending incremented,
+                        * never get Faulty cleared, and never get Blocked set.
+                        * So we can synchronize_rcu now rather than once per device
+                        */
+                       remove_some = true;
+                       set_bit(RemoveSynchronized, &rdev->flags);
+               }
+       }
+
+       if (remove_some)
+               synchronize_rcu();
+       rdev_for_each(rdev, mddev) {
                if ((this == NULL || rdev == this) &&
                    rdev->raid_disk >= 0 &&
                    !test_bit(Blocked, &rdev->flags) &&
-                   (test_bit(Faulty, &rdev->flags) ||
+                   ((test_bit(RemoveSynchronized, &rdev->flags) ||
                     (!test_bit(In_sync, &rdev->flags) &&
                      !test_bit(Journal, &rdev->flags))) &&
-                   atomic_read(&rdev->nr_pending)==0) {
+                   atomic_read(&rdev->nr_pending)==0)) {
                        if (mddev->pers->hot_remove_disk(
                                    mddev, rdev) == 0) {
                                sysfs_unlink_rdev(mddev, rdev);
@@ -8204,6 +8224,10 @@ static int remove_and_add_spares(struct mddev *mddev,
                                removed++;
                        }
                }
+               if (remove_some && test_bit(RemoveSynchronized, &rdev->flags))
+                       clear_bit(RemoveSynchronized, &rdev->flags);
+       }
+
        if (removed && mddev->kobj.sd)
                sysfs_notify(&mddev->kobj, NULL, "degraded");
 
@@ -8506,6 +8530,11 @@ void md_reap_sync_thread(struct mddev *mddev)
                        rdev->saved_raid_disk = -1;
 
        md_update_sb(mddev, 1);
+       /* MD_CHANGE_PENDING should be cleared by md_update_sb, so we can
+        * call resync_finish here if MD_CLUSTER_RESYNC_LOCKED is set by
+        * clustered raid */
+       if (test_and_clear_bit(MD_CLUSTER_RESYNC_LOCKED, &mddev->flags))
+               md_cluster_ops->resync_finish(mddev);
        clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
        clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
        clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
@@ -8803,6 +8832,7 @@ EXPORT_SYMBOL(md_reload_sb);
  * at boot time.
  */
 
+static DEFINE_MUTEX(detected_devices_mutex);
 static LIST_HEAD(all_detected_devices);
 struct detected_devices_node {
        struct list_head list;
@@ -8816,7 +8846,9 @@ void md_autodetect_dev(dev_t dev)
        node_detected_dev = kzalloc(sizeof(*node_detected_dev), GFP_KERNEL);
        if (node_detected_dev) {
                node_detected_dev->dev = dev;
+               mutex_lock(&detected_devices_mutex);
                list_add_tail(&node_detected_dev->list, &all_detected_devices);
+               mutex_unlock(&detected_devices_mutex);
        } else {
                printk(KERN_CRIT "md: md_autodetect_dev: kzalloc failed"
                        ", skipping dev(%d,%d)\n", MAJOR(dev), MINOR(dev));
@@ -8835,6 +8867,7 @@ static void autostart_arrays(int part)
 
        printk(KERN_INFO "md: Autodetecting RAID arrays.\n");
 
+       mutex_lock(&detected_devices_mutex);
        while (!list_empty(&all_detected_devices) && i_scanned < INT_MAX) {
                i_scanned++;
                node_detected_dev = list_entry(all_detected_devices.next,
@@ -8853,6 +8886,7 @@ static void autostart_arrays(int part)
                list_add(&rdev->same_set, &pending_raid_disks);
                i_passed++;
        }
+       mutex_unlock(&detected_devices_mutex);
 
        printk(KERN_INFO "md: Scanned %d and added %d devices.\n",
                                                i_scanned, i_passed);
index b4f3352..20c6675 100644 (file)
@@ -99,7 +99,7 @@ struct md_rdev {
        atomic_t        read_errors;    /* number of consecutive read errors that
                                         * we have tried to ignore.
                                         */
-       struct timespec last_read_error;        /* monotonic time since our
+       time64_t        last_read_error;        /* monotonic time since our
                                                 * last read error
                                                 */
        atomic_t        corrected_errors; /* number of corrected read errors,
@@ -163,6 +163,11 @@ enum flag_bits {
                                 * than other devices in the array
                                 */
        ClusterRemove,
+       RemoveSynchronized,     /* synchronize_rcu() was called after
+                                * this device was known to be faulty,
+                                * so it is safe to remove without
+                                * another synchronize_rcu() call.
+                                */
 };
 
 static inline int is_badblock(struct md_rdev *rdev, sector_t s, int sectors,
@@ -204,6 +209,9 @@ struct mddev {
 #define MD_RELOAD_SB   7       /* Reload the superblock because another node
                                 * updated it.
                                 */
+#define MD_CLUSTER_RESYNC_LOCKED 8 /* cluster raid only, which means node
+                                   * already took resync lock, need to
+                                   * release the lock */
 
        int                             suspended;
        atomic_t                        active_io;
index 72ea98e..4974682 100644 (file)
@@ -43,7 +43,8 @@ static int multipath_map (struct mpconf *conf)
        rcu_read_lock();
        for (i = 0; i < disks; i++) {
                struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev);
-               if (rdev && test_bit(In_sync, &rdev->flags)) {
+               if (rdev && test_bit(In_sync, &rdev->flags) &&
+                   !test_bit(Faulty, &rdev->flags)) {
                        atomic_inc(&rdev->nr_pending);
                        rcu_read_unlock();
                        return i;
@@ -141,17 +142,19 @@ static void multipath_make_request(struct mddev *mddev, struct bio * bio)
        return;
 }
 
-static void multipath_status (struct seq_file *seq, struct mddev *mddev)
+static void multipath_status(struct seq_file *seq, struct mddev *mddev)
 {
        struct mpconf *conf = mddev->private;
        int i;
 
        seq_printf (seq, " [%d/%d] [", conf->raid_disks,
                    conf->raid_disks - mddev->degraded);
-       for (i = 0; i < conf->raid_disks; i++)
-               seq_printf (seq, "%s",
-                              conf->multipaths[i].rdev &&
-                              test_bit(In_sync, &conf->multipaths[i].rdev->flags) ? "U" : "_");
+       rcu_read_lock();
+       for (i = 0; i < conf->raid_disks; i++) {
+               struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev);
+               seq_printf (seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
+       }
+       rcu_read_unlock();
        seq_printf (seq, "]");
 }
 
@@ -295,12 +298,14 @@ static int multipath_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
                        goto abort;
                }
                p->rdev = NULL;
-               synchronize_rcu();
-               if (atomic_read(&rdev->nr_pending)) {
-                       /* lost the race, try later */
-                       err = -EBUSY;
-                       p->rdev = rdev;
-                       goto abort;
+               if (!test_bit(RemoveSynchronized, &rdev->flags)) {
+                       synchronize_rcu();
+                       if (atomic_read(&rdev->nr_pending)) {
+                               /* lost the race, try later */
+                               err = -EBUSY;
+                               p->rdev = rdev;
+                               goto abort;
+                       }
                }
                err = md_integrity_register(mddev);
        }
index 4e6da44..46168ef 100644 (file)
@@ -319,14 +319,13 @@ static void raid1_end_read_request(struct bio *bio)
 {
        int uptodate = !bio->bi_error;
        struct r1bio *r1_bio = bio->bi_private;
-       int mirror;
        struct r1conf *conf = r1_bio->mddev->private;
+       struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev;
 
-       mirror = r1_bio->read_disk;
        /*
         * this branch is our 'one mirror IO has finished' event handler:
         */
-       update_head_pos(mirror, r1_bio);
+       update_head_pos(r1_bio->read_disk, r1_bio);
 
        if (uptodate)
                set_bit(R1BIO_Uptodate, &r1_bio->state);
@@ -339,14 +338,14 @@ static void raid1_end_read_request(struct bio *bio)
                spin_lock_irqsave(&conf->device_lock, flags);
                if (r1_bio->mddev->degraded == conf->raid_disks ||
                    (r1_bio->mddev->degraded == conf->raid_disks-1 &&
-                    test_bit(In_sync, &conf->mirrors[mirror].rdev->flags)))
+                    test_bit(In_sync, &rdev->flags)))
                        uptodate = 1;
                spin_unlock_irqrestore(&conf->device_lock, flags);
        }
 
        if (uptodate) {
                raid_end_bio_io(r1_bio);
-               rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
+               rdev_dec_pending(rdev, conf->mddev);
        } else {
                /*
                 * oops, read error:
@@ -356,7 +355,7 @@ static void raid1_end_read_request(struct bio *bio)
                        KERN_ERR "md/raid1:%s: %s: "
                        "rescheduling sector %llu\n",
                        mdname(conf->mddev),
-                       bdevname(conf->mirrors[mirror].rdev->bdev,
+                       bdevname(rdev->bdev,
                                 b),
                        (unsigned long long)r1_bio->sector);
                set_bit(R1BIO_ReadError, &r1_bio->state);
@@ -403,20 +402,18 @@ static void r1_bio_write_done(struct r1bio *r1_bio)
 static void raid1_end_write_request(struct bio *bio)
 {
        struct r1bio *r1_bio = bio->bi_private;
-       int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
+       int behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
        struct r1conf *conf = r1_bio->mddev->private;
        struct bio *to_put = NULL;
-
-       mirror = find_bio_disk(r1_bio, bio);
+       int mirror = find_bio_disk(r1_bio, bio);
+       struct md_rdev *rdev = conf->mirrors[mirror].rdev;
 
        /*
         * 'one mirror IO has finished' event handler:
         */
        if (bio->bi_error) {
-               set_bit(WriteErrorSeen,
-                       &conf->mirrors[mirror].rdev->flags);
-               if (!test_and_set_bit(WantReplacement,
-                                     &conf->mirrors[mirror].rdev->flags))
+               set_bit(WriteErrorSeen, &rdev->flags);
+               if (!test_and_set_bit(WantReplacement, &rdev->flags))
                        set_bit(MD_RECOVERY_NEEDED, &
                                conf->mddev->recovery);
 
@@ -445,13 +442,12 @@ static void raid1_end_write_request(struct bio *bio)
                 * before rdev->recovery_offset, but for simplicity we don't
                 * check this here.
                 */
-               if (test_bit(In_sync, &conf->mirrors[mirror].rdev->flags) &&
-                   !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags))
+               if (test_bit(In_sync, &rdev->flags) &&
+                   !test_bit(Faulty, &rdev->flags))
                        set_bit(R1BIO_Uptodate, &r1_bio->state);
 
                /* Maybe we can clear some bad blocks. */
-               if (is_badblock(conf->mirrors[mirror].rdev,
-                               r1_bio->sector, r1_bio->sectors,
+               if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
                                &first_bad, &bad_sectors)) {
                        r1_bio->bios[mirror] = IO_MADE_GOOD;
                        set_bit(R1BIO_MadeGood, &r1_bio->state);
@@ -459,7 +455,7 @@ static void raid1_end_write_request(struct bio *bio)
        }
 
        if (behind) {
-               if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
+               if (test_bit(WriteMostly, &rdev->flags))
                        atomic_dec(&r1_bio->behind_remaining);
 
                /*
@@ -483,8 +479,7 @@ static void raid1_end_write_request(struct bio *bio)
                }
        }
        if (r1_bio->bios[mirror] == NULL)
-               rdev_dec_pending(conf->mirrors[mirror].rdev,
-                                conf->mddev);
+               rdev_dec_pending(rdev, conf->mddev);
 
        /*
         * Let's see if all mirrored write operations have finished
@@ -689,13 +684,6 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
                if (!rdev)
                        goto retry;
                atomic_inc(&rdev->nr_pending);
-               if (test_bit(Faulty, &rdev->flags)) {
-                       /* cannot risk returning a device that failed
-                        * before we inc'ed nr_pending
-                        */
-                       rdev_dec_pending(rdev, conf->mddev);
-                       goto retry;
-               }
                sectors = best_good_sectors;
 
                if (conf->mirrors[best_disk].next_seq_sect != this_sector)
@@ -1666,13 +1654,16 @@ static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
                        goto abort;
                }
                p->rdev = NULL;
-               synchronize_rcu();
-               if (atomic_read(&rdev->nr_pending)) {
-                       /* lost the race, try later */
-                       err = -EBUSY;
-                       p->rdev = rdev;
-                       goto abort;
-               } else if (conf->mirrors[conf->raid_disks + number].rdev) {
+               if (!test_bit(RemoveSynchronized, &rdev->flags)) {
+                       synchronize_rcu();
+                       if (atomic_read(&rdev->nr_pending)) {
+                               /* lost the race, try later */
+                               err = -EBUSY;
+                               p->rdev = rdev;
+                               goto abort;
+                       }
+               }
+               if (conf->mirrors[conf->raid_disks + number].rdev) {
                        /* We just removed a device that is being replaced.
                         * Move down the replacement.  We drain all IO before
                         * doing this to avoid confusion.
@@ -1719,11 +1710,9 @@ static void end_sync_write(struct bio *bio)
        struct r1bio *r1_bio = bio->bi_private;
        struct mddev *mddev = r1_bio->mddev;
        struct r1conf *conf = mddev->private;
-       int mirror=0;
        sector_t first_bad;
        int bad_sectors;
-
-       mirror = find_bio_disk(r1_bio, bio);
+       struct md_rdev *rdev = conf->mirrors[find_bio_disk(r1_bio, bio)].rdev;
 
        if (!uptodate) {
                sector_t sync_blocks = 0;
@@ -1736,16 +1725,12 @@ static void end_sync_write(struct bio *bio)
                        s += sync_blocks;
                        sectors_to_go -= sync_blocks;
                } while (sectors_to_go > 0);
-               set_bit(WriteErrorSeen,
-                       &conf->mirrors[mirror].rdev->flags);
-               if (!test_and_set_bit(WantReplacement,
-                                     &conf->mirrors[mirror].rdev->flags))
+               set_bit(WriteErrorSeen, &rdev->flags);
+               if (!test_and_set_bit(WantReplacement, &rdev->flags))
                        set_bit(MD_RECOVERY_NEEDED, &
                                mddev->recovery);
                set_bit(R1BIO_WriteError, &r1_bio->state);
-       } else if (is_badblock(conf->mirrors[mirror].rdev,
-                              r1_bio->sector,
-                              r1_bio->sectors,
+       } else if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
                               &first_bad, &bad_sectors) &&
                   !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
                                r1_bio->sector,
@@ -2072,29 +2057,30 @@ static void fix_read_error(struct r1conf *conf, int read_disk,
                        s = PAGE_SIZE >> 9;
 
                do {
-                       /* Note: no rcu protection needed here
-                        * as this is synchronous in the raid1d thread
-                        * which is the thread that might remove
-                        * a device.  If raid1d ever becomes multi-threaded....
-                        */
                        sector_t first_bad;
                        int bad_sectors;
 
-                       rdev = conf->mirrors[d].rdev;
+                       rcu_read_lock();
+                       rdev = rcu_dereference(conf->mirrors[d].rdev);
                        if (rdev &&
                            (test_bit(In_sync, &rdev->flags) ||
                             (!test_bit(Faulty, &rdev->flags) &&
                              rdev->recovery_offset >= sect + s)) &&
                            is_badblock(rdev, sect, s,
-                                       &first_bad, &bad_sectors) == 0 &&
-                           sync_page_io(rdev, sect, s<<9,
+                                       &first_bad, &bad_sectors) == 0) {
+                               atomic_inc(&rdev->nr_pending);
+                               rcu_read_unlock();
+                               if (sync_page_io(rdev, sect, s<<9,
                                         conf->tmppage, REQ_OP_READ, 0, false))
-                               success = 1;
-                       else {
-                               d++;
-                               if (d == conf->raid_disks * 2)
-                                       d = 0;
-                       }
+                                       success = 1;
+                               rdev_dec_pending(rdev, mddev);
+                               if (success)
+                                       break;
+                       } else
+                               rcu_read_unlock();
+                       d++;
+                       if (d == conf->raid_disks * 2)
+                               d = 0;
                } while (!success && d != read_disk);
 
                if (!success) {
@@ -2110,11 +2096,17 @@ static void fix_read_error(struct r1conf *conf, int read_disk,
                        if (d==0)
                                d = conf->raid_disks * 2;
                        d--;
-                       rdev = conf->mirrors[d].rdev;
+                       rcu_read_lock();
+                       rdev = rcu_dereference(conf->mirrors[d].rdev);
                        if (rdev &&
-                           !test_bit(Faulty, &rdev->flags))
+                           !test_bit(Faulty, &rdev->flags)) {
+                               atomic_inc(&rdev->nr_pending);
+                               rcu_read_unlock();
                                r1_sync_page_io(rdev, sect, s,
                                                conf->tmppage, WRITE);
+                               rdev_dec_pending(rdev, mddev);
+                       } else
+                               rcu_read_unlock();
                }
                d = start;
                while (d != read_disk) {
@@ -2122,9 +2114,12 @@ static void fix_read_error(struct r1conf *conf, int read_disk,
                        if (d==0)
                                d = conf->raid_disks * 2;
                        d--;
-                       rdev = conf->mirrors[d].rdev;
+                       rcu_read_lock();
+                       rdev = rcu_dereference(conf->mirrors[d].rdev);
                        if (rdev &&
                            !test_bit(Faulty, &rdev->flags)) {
+                               atomic_inc(&rdev->nr_pending);
+                               rcu_read_unlock();
                                if (r1_sync_page_io(rdev, sect, s,
                                                    conf->tmppage, READ)) {
                                        atomic_add(s, &rdev->corrected_errors);
@@ -2133,10 +2128,12 @@ static void fix_read_error(struct r1conf *conf, int read_disk,
                                               "(%d sectors at %llu on %s)\n",
                                               mdname(mddev), s,
                                               (unsigned long long)(sect +
-                                                  rdev->data_offset),
+                                                                   rdev->data_offset),
                                               bdevname(rdev->bdev, b));
                                }
-                       }
+                               rdev_dec_pending(rdev, mddev);
+                       } else
+                               rcu_read_unlock();
                }
                sectors -= s;
                sect += s;
@@ -2534,6 +2531,13 @@ static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
                return sync_blocks;
        }
 
+       /*
+        * If there is non-resync activity waiting for a turn, then let it
+        * though before starting on this new sync request.
+        */
+       if (conf->nr_waiting)
+               schedule_timeout_uninterruptible(1);
+
        /* we are incrementing sector_nr below. To be safe, we check against
         * sector_nr + two times RESYNC_SECTORS
         */
index 26ae74f..ed29fc8 100644 (file)
@@ -707,7 +707,6 @@ static struct md_rdev *read_balance(struct r10conf *conf,
 
        raid10_find_phys(conf, r10_bio);
        rcu_read_lock();
-retry:
        sectors = r10_bio->sectors;
        best_slot = -1;
        best_rdev = NULL;
@@ -804,13 +803,6 @@ retry:
 
        if (slot >= 0) {
                atomic_inc(&rdev->nr_pending);
-               if (test_bit(Faulty, &rdev->flags)) {
-                       /* Cannot risk returning a device that failed
-                        * before we inc'ed nr_pending
-                        */
-                       rdev_dec_pending(rdev, conf->mddev);
-                       goto retry;
-               }
                r10_bio->read_slot = slot;
        } else
                rdev = NULL;
@@ -913,7 +905,7 @@ static void raise_barrier(struct r10conf *conf, int force)
 
        /* Now wait for all pending IO to complete */
        wait_event_lock_irq(conf->wait_barrier,
-                           !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
+                           !atomic_read(&conf->nr_pending) && conf->barrier < RESYNC_DEPTH,
                            conf->resync_lock);
 
        spin_unlock_irq(&conf->resync_lock);
@@ -944,23 +936,23 @@ static void wait_barrier(struct r10conf *conf)
                 */
                wait_event_lock_irq(conf->wait_barrier,
                                    !conf->barrier ||
-                                   (conf->nr_pending &&
+                                   (atomic_read(&conf->nr_pending) &&
                                     current->bio_list &&
                                     !bio_list_empty(current->bio_list)),
                                    conf->resync_lock);
                conf->nr_waiting--;
+               if (!conf->nr_waiting)
+                       wake_up(&conf->wait_barrier);
        }
-       conf->nr_pending++;
+       atomic_inc(&conf->nr_pending);
        spin_unlock_irq(&conf->resync_lock);
 }
 
 static void allow_barrier(struct r10conf *conf)
 {
-       unsigned long flags;
-       spin_lock_irqsave(&conf->resync_lock, flags);
-       conf->nr_pending--;
-       spin_unlock_irqrestore(&conf->resync_lock, flags);
-       wake_up(&conf->wait_barrier);
+       if ((atomic_dec_and_test(&conf->nr_pending)) ||
+                       (conf->array_freeze_pending))
+               wake_up(&conf->wait_barrier);
 }
 
 static void freeze_array(struct r10conf *conf, int extra)
@@ -978,13 +970,15 @@ static void freeze_array(struct r10conf *conf, int extra)
         * we continue.
         */
        spin_lock_irq(&conf->resync_lock);
+       conf->array_freeze_pending++;
        conf->barrier++;
        conf->nr_waiting++;
        wait_event_lock_irq_cmd(conf->wait_barrier,
-                               conf->nr_pending == conf->nr_queued+extra,
+                               atomic_read(&conf->nr_pending) == conf->nr_queued+extra,
                                conf->resync_lock,
                                flush_pending_writes(conf));
 
+       conf->array_freeze_pending--;
        spin_unlock_irq(&conf->resync_lock);
 }
 
@@ -1499,10 +1493,12 @@ static void raid10_status(struct seq_file *seq, struct mddev *mddev)
        }
        seq_printf(seq, " [%d/%d] [", conf->geo.raid_disks,
                                        conf->geo.raid_disks - mddev->degraded);
-       for (i = 0; i < conf->geo.raid_disks; i++)
-               seq_printf(seq, "%s",
-                             conf->mirrors[i].rdev &&
-                             test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
+       rcu_read_lock();
+       for (i = 0; i < conf->geo.raid_disks; i++) {
+               struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
+               seq_printf(seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
+       }
+       rcu_read_unlock();
        seq_printf(seq, "]");
 }
 
@@ -1600,7 +1596,7 @@ static void raid10_error(struct mddev *mddev, struct md_rdev *rdev)
 static void print_conf(struct r10conf *conf)
 {
        int i;
-       struct raid10_info *tmp;
+       struct md_rdev *rdev;
 
        printk(KERN_DEBUG "RAID10 conf printout:\n");
        if (!conf) {
@@ -1610,14 +1606,16 @@ static void print_conf(struct r10conf *conf)
        printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->geo.raid_disks - conf->mddev->degraded,
                conf->geo.raid_disks);
 
+       /* This is only called with ->reconfix_mutex held, so
+        * rcu protection of rdev is not needed */
        for (i = 0; i < conf->geo.raid_disks; i++) {
                char b[BDEVNAME_SIZE];
-               tmp = conf->mirrors + i;
-               if (tmp->rdev)
+               rdev = conf->mirrors[i].rdev;
+               if (rdev)
                        printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
-                               i, !test_bit(In_sync, &tmp->rdev->flags),
-                               !test_bit(Faulty, &tmp->rdev->flags),
-                               bdevname(tmp->rdev->bdev,b));
+                               i, !test_bit(In_sync, &rdev->flags),
+                               !test_bit(Faulty, &rdev->flags),
+                               bdevname(rdev->bdev,b));
        }
 }
 
@@ -1766,7 +1764,7 @@ static int raid10_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
                err = -EBUSY;
                goto abort;
        }
-       /* Only remove faulty devices if recovery
+       /* Only remove non-faulty devices if recovery
         * is not possible.
         */
        if (!test_bit(Faulty, &rdev->flags) &&
@@ -1778,13 +1776,16 @@ static int raid10_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
                goto abort;
        }
        *rdevp = NULL;
-       synchronize_rcu();
-       if (atomic_read(&rdev->nr_pending)) {
-               /* lost the race, try later */
-               err = -EBUSY;
-               *rdevp = rdev;
-               goto abort;
-       } else if (p->replacement) {
+       if (!test_bit(RemoveSynchronized, &rdev->flags)) {
+               synchronize_rcu();
+               if (atomic_read(&rdev->nr_pending)) {
+                       /* lost the race, try later */
+                       err = -EBUSY;
+                       *rdevp = rdev;
+                       goto abort;
+               }
+       }
+       if (p->replacement) {
                /* We must have just cleared 'rdev' */
                p->rdev = p->replacement;
                clear_bit(Replacement, &p->replacement->flags);
@@ -2171,21 +2172,20 @@ static void recovery_request_write(struct mddev *mddev, struct r10bio *r10_bio)
  */
 static void check_decay_read_errors(struct mddev *mddev, struct md_rdev *rdev)
 {
-       struct timespec cur_time_mon;
+       long cur_time_mon;
        unsigned long hours_since_last;
        unsigned int read_errors = atomic_read(&rdev->read_errors);
 
-       ktime_get_ts(&cur_time_mon);
+       cur_time_mon = ktime_get_seconds();
 
-       if (rdev->last_read_error.tv_sec == 0 &&
-           rdev->last_read_error.tv_nsec == 0) {
+       if (rdev->last_read_error == 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;
+       hours_since_last = (long)(cur_time_mon -
+                           rdev->last_read_error) / 3600;
 
        rdev->last_read_error = cur_time_mon;
 
@@ -2264,7 +2264,7 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10
                printk(KERN_NOTICE
                       "md/raid10:%s: %s: Failing raid device\n",
                       mdname(mddev), b);
-               md_error(mddev, conf->mirrors[d].rdev);
+               md_error(mddev, rdev);
                r10_bio->devs[r10_bio->read_slot].bio = IO_BLOCKED;
                return;
        }
@@ -2287,6 +2287,7 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10
                        rdev = rcu_dereference(conf->mirrors[d].rdev);
                        if (rdev &&
                            test_bit(In_sync, &rdev->flags) &&
+                           !test_bit(Faulty, &rdev->flags) &&
                            is_badblock(rdev, r10_bio->devs[sl].addr + sect, s,
                                        &first_bad, &bad_sectors) == 0) {
                                atomic_inc(&rdev->nr_pending);
@@ -2340,6 +2341,7 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10
                        d = r10_bio->devs[sl].devnum;
                        rdev = rcu_dereference(conf->mirrors[d].rdev);
                        if (!rdev ||
+                           test_bit(Faulty, &rdev->flags) ||
                            !test_bit(In_sync, &rdev->flags))
                                continue;
 
@@ -2379,6 +2381,7 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10
                        d = r10_bio->devs[sl].devnum;
                        rdev = rcu_dereference(conf->mirrors[d].rdev);
                        if (!rdev ||
+                           test_bit(Faulty, &rdev->flags) ||
                            !test_bit(In_sync, &rdev->flags))
                                continue;
 
@@ -2876,11 +2879,14 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                                /* Completed a full sync so the replacements
                                 * are now fully recovered.
                                 */
-                               for (i = 0; i < conf->geo.raid_disks; i++)
-                                       if (conf->mirrors[i].replacement)
-                                               conf->mirrors[i].replacement
-                                                       ->recovery_offset
-                                                       = MaxSector;
+                               rcu_read_lock();
+                               for (i = 0; i < conf->geo.raid_disks; i++) {
+                                       struct md_rdev *rdev =
+                                               rcu_dereference(conf->mirrors[i].replacement);
+                                       if (rdev)
+                                               rdev->recovery_offset = MaxSector;
+                               }
+                               rcu_read_unlock();
                        }
                        conf->fullsync = 0;
                }
@@ -2911,6 +2917,13 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
            max_sector > (sector_nr | chunk_mask))
                max_sector = (sector_nr | chunk_mask) + 1;
 
+       /*
+        * If there is non-resync activity waiting for a turn, then let it
+        * though before starting on this new sync request.
+        */
+       if (conf->nr_waiting)
+               schedule_timeout_uninterruptible(1);
+
        /* Again, very different code for resync and recovery.
         * Both must result in an r10bio with a list of bios that
         * have bi_end_io, bi_sector, bi_bdev set,
@@ -2939,14 +2952,20 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                        int must_sync;
                        int any_working;
                        struct raid10_info *mirror = &conf->mirrors[i];
+                       struct md_rdev *mrdev, *mreplace;
 
-                       if ((mirror->rdev == NULL ||
-                            test_bit(In_sync, &mirror->rdev->flags))
-                           &&
-                           (mirror->replacement == NULL ||
-                            test_bit(Faulty,
-                                     &mirror->replacement->flags)))
+                       rcu_read_lock();
+                       mrdev = rcu_dereference(mirror->rdev);
+                       mreplace = rcu_dereference(mirror->replacement);
+
+                       if ((mrdev == NULL ||
+                            test_bit(Faulty, &mrdev->flags) ||
+                            test_bit(In_sync, &mrdev->flags)) &&
+                           (mreplace == NULL ||
+                            test_bit(Faulty, &mreplace->flags))) {
+                               rcu_read_unlock();
                                continue;
+                       }
 
                        still_degraded = 0;
                        /* want to reconstruct this device */
@@ -2956,8 +2975,11 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                                /* last stripe is not complete - don't
                                 * try to recover this sector.
                                 */
+                               rcu_read_unlock();
                                continue;
                        }
+                       if (mreplace && test_bit(Faulty, &mreplace->flags))
+                               mreplace = NULL;
                        /* Unless we are doing a full sync, or a replacement
                         * we only need to recover the block if it is set in
                         * the bitmap
@@ -2967,14 +2989,19 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                        if (sync_blocks < max_sync)
                                max_sync = sync_blocks;
                        if (!must_sync &&
-                           mirror->replacement == NULL &&
+                           mreplace == NULL &&
                            !conf->fullsync) {
                                /* yep, skip the sync_blocks here, but don't assume
                                 * that there will never be anything to do here
                                 */
                                chunks_skipped = -1;
+                               rcu_read_unlock();
                                continue;
                        }
+                       atomic_inc(&mrdev->nr_pending);
+                       if (mreplace)
+                               atomic_inc(&mreplace->nr_pending);
+                       rcu_read_unlock();
 
                        r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
                        r10_bio->state = 0;
@@ -2993,12 +3020,15 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                        /* Need to check if the array will still be
                         * degraded
                         */
-                       for (j = 0; j < conf->geo.raid_disks; j++)
-                               if (conf->mirrors[j].rdev == NULL ||
-                                   test_bit(Faulty, &conf->mirrors[j].rdev->flags)) {
+                       rcu_read_lock();
+                       for (j = 0; j < conf->geo.raid_disks; j++) {
+                               struct md_rdev *rdev = rcu_dereference(
+                                       conf->mirrors[j].rdev);
+                               if (rdev == NULL || test_bit(Faulty, &rdev->flags)) {
                                        still_degraded = 1;
                                        break;
                                }
+                       }
 
                        must_sync = bitmap_start_sync(mddev->bitmap, sect,
                                                      &sync_blocks, still_degraded);
@@ -3008,15 +3038,15 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                                int k;
                                int d = r10_bio->devs[j].devnum;
                                sector_t from_addr, to_addr;
-                               struct md_rdev *rdev;
+                               struct md_rdev *rdev =
+                                       rcu_dereference(conf->mirrors[d].rdev);
                                sector_t sector, first_bad;
                                int bad_sectors;
-                               if (!conf->mirrors[d].rdev ||
-                                   !test_bit(In_sync, &conf->mirrors[d].rdev->flags))
+                               if (!rdev ||
+                                   !test_bit(In_sync, &rdev->flags))
                                        continue;
                                /* This is where we read from */
                                any_working = 1;
-                               rdev = conf->mirrors[d].rdev;
                                sector = r10_bio->devs[j].addr;
 
                                if (is_badblock(rdev, sector, max_sync,
@@ -3055,8 +3085,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                                r10_bio->devs[1].devnum = i;
                                r10_bio->devs[1].addr = to_addr;
 
-                               rdev = mirror->rdev;
-                               if (!test_bit(In_sync, &rdev->flags)) {
+                               if (!test_bit(In_sync, &mrdev->flags)) {
                                        bio = r10_bio->devs[1].bio;
                                        bio_reset(bio);
                                        bio->bi_next = biolist;
@@ -3065,8 +3094,8 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                                        bio->bi_end_io = end_sync_write;
                                        bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
                                        bio->bi_iter.bi_sector = to_addr
-                                               + rdev->data_offset;
-                                       bio->bi_bdev = rdev->bdev;
+                                               + mrdev->data_offset;
+                                       bio->bi_bdev = mrdev->bdev;
                                        atomic_inc(&r10_bio->remaining);
                                } else
                                        r10_bio->devs[1].bio->bi_end_io = NULL;
@@ -3075,8 +3104,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                                bio = r10_bio->devs[1].repl_bio;
                                if (bio)
                                        bio->bi_end_io = NULL;
-                               rdev = mirror->replacement;
-                               /* Note: if rdev != NULL, then bio
+                               /* Note: if mreplace != NULL, then bio
                                 * cannot be NULL as r10buf_pool_alloc will
                                 * have allocated it.
                                 * So the second test here is pointless.
@@ -3084,8 +3112,8 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                                 * this comment keeps human reviewers
                                 * happy.
                                 */
-                               if (rdev == NULL || bio == NULL ||
-                                   test_bit(Faulty, &rdev->flags))
+                               if (mreplace == NULL || bio == NULL ||
+                                   test_bit(Faulty, &mreplace->flags))
                                        break;
                                bio_reset(bio);
                                bio->bi_next = biolist;
@@ -3094,11 +3122,12 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                                bio->bi_end_io = end_sync_write;
                                bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
                                bio->bi_iter.bi_sector = to_addr +
-                                       rdev->data_offset;
-                               bio->bi_bdev = rdev->bdev;
+                                       mreplace->data_offset;
+                               bio->bi_bdev = mreplace->bdev;
                                atomic_inc(&r10_bio->remaining);
                                break;
                        }
+                       rcu_read_unlock();
                        if (j == conf->copies) {
                                /* Cannot recover, so abort the recovery or
                                 * record a bad block */
@@ -3111,15 +3140,15 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                                                if (r10_bio->devs[k].devnum == i)
                                                        break;
                                        if (!test_bit(In_sync,
-                                                     &mirror->rdev->flags)
+                                                     &mrdev->flags)
                                            && !rdev_set_badblocks(
-                                                   mirror->rdev,
+                                                   mrdev,
                                                    r10_bio->devs[k].addr,
                                                    max_sync, 0))
                                                any_working = 0;
-                                       if (mirror->replacement &&
+                                       if (mreplace &&
                                            !rdev_set_badblocks(
-                                                   mirror->replacement,
+                                                   mreplace,
                                                    r10_bio->devs[k].addr,
                                                    max_sync, 0))
                                                any_working = 0;
@@ -3137,8 +3166,14 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                                if (rb2)
                                        atomic_dec(&rb2->remaining);
                                r10_bio = rb2;
+                               rdev_dec_pending(mrdev, mddev);
+                               if (mreplace)
+                                       rdev_dec_pending(mreplace, mddev);
                                break;
                        }
+                       rdev_dec_pending(mrdev, mddev);
+                       if (mreplace)
+                               rdev_dec_pending(mreplace, mddev);
                }
                if (biolist == NULL) {
                        while (r10_bio) {
@@ -3183,6 +3218,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                        int d = r10_bio->devs[i].devnum;
                        sector_t first_bad, sector;
                        int bad_sectors;
+                       struct md_rdev *rdev;
 
                        if (r10_bio->devs[i].repl_bio)
                                r10_bio->devs[i].repl_bio->bi_end_io = NULL;
@@ -3190,12 +3226,14 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                        bio = r10_bio->devs[i].bio;
                        bio_reset(bio);
                        bio->bi_error = -EIO;
-                       if (conf->mirrors[d].rdev == NULL ||
-                           test_bit(Faulty, &conf->mirrors[d].rdev->flags))
+                       rcu_read_lock();
+                       rdev = rcu_dereference(conf->mirrors[d].rdev);
+                       if (rdev == NULL || test_bit(Faulty, &rdev->flags)) {
+                               rcu_read_unlock();
                                continue;
+                       }
                        sector = r10_bio->devs[i].addr;
-                       if (is_badblock(conf->mirrors[d].rdev,
-                                       sector, max_sync,
+                       if (is_badblock(rdev, sector, max_sync,
                                        &first_bad, &bad_sectors)) {
                                if (first_bad > sector)
                                        max_sync = first_bad - sector;
@@ -3203,25 +3241,28 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                                        bad_sectors -= (sector - first_bad);
                                        if (max_sync > bad_sectors)
                                                max_sync = bad_sectors;
+                                       rcu_read_unlock();
                                        continue;
                                }
                        }
-                       atomic_inc(&conf->mirrors[d].rdev->nr_pending);
+                       atomic_inc(&rdev->nr_pending);
                        atomic_inc(&r10_bio->remaining);
                        bio->bi_next = biolist;
                        biolist = bio;
                        bio->bi_private = r10_bio;
                        bio->bi_end_io = end_sync_read;
                        bio_set_op_attrs(bio, REQ_OP_READ, 0);
-                       bio->bi_iter.bi_sector = sector +
-                               conf->mirrors[d].rdev->data_offset;
-                       bio->bi_bdev = conf->mirrors[d].rdev->bdev;
+                       bio->bi_iter.bi_sector = sector + rdev->data_offset;
+                       bio->bi_bdev = rdev->bdev;
                        count++;
 
-                       if (conf->mirrors[d].replacement == NULL ||
-                           test_bit(Faulty,
-                                    &conf->mirrors[d].replacement->flags))
+                       rdev = rcu_dereference(conf->mirrors[d].replacement);
+                       if (rdev == NULL || test_bit(Faulty, &rdev->flags)) {
+                               rcu_read_unlock();
                                continue;
+                       }
+                       atomic_inc(&rdev->nr_pending);
+                       rcu_read_unlock();
 
                        /* Need to set up for writing to the replacement */
                        bio = r10_bio->devs[i].repl_bio;
@@ -3229,15 +3270,13 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                        bio->bi_error = -EIO;
 
                        sector = r10_bio->devs[i].addr;
-                       atomic_inc(&conf->mirrors[d].rdev->nr_pending);
                        bio->bi_next = biolist;
                        biolist = bio;
                        bio->bi_private = r10_bio;
                        bio->bi_end_io = end_sync_write;
                        bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
-                       bio->bi_iter.bi_sector = sector +
-                               conf->mirrors[d].replacement->data_offset;
-                       bio->bi_bdev = conf->mirrors[d].replacement->bdev;
+                       bio->bi_iter.bi_sector = sector + rdev->data_offset;
+                       bio->bi_bdev = rdev->bdev;
                        count++;
                }
 
@@ -3504,6 +3543,7 @@ static struct r10conf *setup_conf(struct mddev *mddev)
 
        spin_lock_init(&conf->resync_lock);
        init_waitqueue_head(&conf->wait_barrier);
+       atomic_set(&conf->nr_pending, 0);
 
        conf->thread = md_register_thread(raid10d, mddev, "raid10");
        if (!conf->thread)
@@ -4333,15 +4373,16 @@ read_more:
        blist = read_bio;
        read_bio->bi_next = NULL;
 
+       rcu_read_lock();
        for (s = 0; s < conf->copies*2; s++) {
                struct bio *b;
                int d = r10_bio->devs[s/2].devnum;
                struct md_rdev *rdev2;
                if (s&1) {
-                       rdev2 = conf->mirrors[d].replacement;
+                       rdev2 = rcu_dereference(conf->mirrors[d].replacement);
                        b = r10_bio->devs[s/2].repl_bio;
                } else {
-                       rdev2 = conf->mirrors[d].rdev;
+                       rdev2 = rcu_dereference(conf->mirrors[d].rdev);
                        b = r10_bio->devs[s/2].bio;
                }
                if (!rdev2 || test_bit(Faulty, &rdev2->flags))
@@ -4386,6 +4427,7 @@ read_more:
                nr_sectors += len >> 9;
        }
 bio_full:
+       rcu_read_unlock();
        r10_bio->sectors = nr_sectors;
 
        /* Now submit the read */
@@ -4437,16 +4479,20 @@ static void reshape_request_write(struct mddev *mddev, struct r10bio *r10_bio)
                struct bio *b;
                int d = r10_bio->devs[s/2].devnum;
                struct md_rdev *rdev;
+               rcu_read_lock();
                if (s&1) {
-                       rdev = conf->mirrors[d].replacement;
+                       rdev = rcu_dereference(conf->mirrors[d].replacement);
                        b = r10_bio->devs[s/2].repl_bio;
                } else {
-                       rdev = conf->mirrors[d].rdev;
+                       rdev = rcu_dereference(conf->mirrors[d].rdev);
                        b = r10_bio->devs[s/2].bio;
                }
-               if (!rdev || test_bit(Faulty, &rdev->flags))
+               if (!rdev || test_bit(Faulty, &rdev->flags)) {
+                       rcu_read_unlock();
                        continue;
+               }
                atomic_inc(&rdev->nr_pending);
+               rcu_read_unlock();
                md_sync_acct(b->bi_bdev, r10_bio->sectors);
                atomic_inc(&r10_bio->remaining);
                b->bi_next = NULL;
@@ -4507,9 +4553,10 @@ static int handle_reshape_read_error(struct mddev *mddev,
                if (s > (PAGE_SIZE >> 9))
                        s = PAGE_SIZE >> 9;
 
+               rcu_read_lock();
                while (!success) {
                        int d = r10b->devs[slot].devnum;
-                       struct md_rdev *rdev = conf->mirrors[d].rdev;
+                       struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev);
                        sector_t addr;
                        if (rdev == NULL ||
                            test_bit(Faulty, &rdev->flags) ||
@@ -4517,11 +4564,15 @@ static int handle_reshape_read_error(struct mddev *mddev,
                                goto failed;
 
                        addr = r10b->devs[slot].addr + idx * PAGE_SIZE;
+                       atomic_inc(&rdev->nr_pending);
+                       rcu_read_unlock();
                        success = sync_page_io(rdev,
                                               addr,
                                               s << 9,
                                               bvec[idx].bv_page,
                                               REQ_OP_READ, 0, false);
+                       rdev_dec_pending(rdev, mddev);
+                       rcu_read_lock();
                        if (success)
                                break;
                failed:
@@ -4531,6 +4582,7 @@ static int handle_reshape_read_error(struct mddev *mddev,
                        if (slot == first_slot)
                                break;
                }
+               rcu_read_unlock();
                if (!success) {
                        /* couldn't read this block, must give up */
                        set_bit(MD_RECOVERY_INTR,
@@ -4600,16 +4652,18 @@ static void raid10_finish_reshape(struct mddev *mddev)
                }
        } else {
                int d;
+               rcu_read_lock();
                for (d = conf->geo.raid_disks ;
                     d < conf->geo.raid_disks - mddev->delta_disks;
                     d++) {
-                       struct md_rdev *rdev = conf->mirrors[d].rdev;
+                       struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev);
                        if (rdev)
                                clear_bit(In_sync, &rdev->flags);
-                       rdev = conf->mirrors[d].replacement;
+                       rdev = rcu_dereference(conf->mirrors[d].replacement);
                        if (rdev)
                                clear_bit(In_sync, &rdev->flags);
                }
+               rcu_read_unlock();
        }
        mddev->layout = mddev->new_layout;
        mddev->chunk_sectors = 1 << conf->geo.chunk_shift;
index 6fc2c75..18ec1f7 100644 (file)
@@ -64,10 +64,11 @@ struct r10conf {
        int                     pending_count;
 
        spinlock_t              resync_lock;
-       int                     nr_pending;
+       atomic_t                nr_pending;
        int                     nr_waiting;
        int                     nr_queued;
        int                     barrier;
+       int                     array_freeze_pending;
        sector_t                next_resync;
        int                     fullsync;  /* set to 1 if a full sync is needed,
                                            * (fresh device added).
index 6953d78..d189e89 100644 (file)
@@ -3080,7 +3080,8 @@ handle_failed_stripe(struct r5conf *conf, struct stripe_head *sh,
                        struct md_rdev *rdev;
                        rcu_read_lock();
                        rdev = rcu_dereference(conf->disks[i].rdev);
-                       if (rdev && test_bit(In_sync, &rdev->flags))
+                       if (rdev && test_bit(In_sync, &rdev->flags) &&
+                           !test_bit(Faulty, &rdev->flags))
                                atomic_inc(&rdev->nr_pending);
                        else
                                rdev = NULL;
@@ -3210,15 +3211,16 @@ handle_failed_sync(struct r5conf *conf, struct stripe_head *sh,
                /* During recovery devices cannot be removed, so
                 * locking and refcounting of rdevs is not needed
                 */
+               rcu_read_lock();
                for (i = 0; i < conf->raid_disks; i++) {
-                       struct md_rdev *rdev = conf->disks[i].rdev;
+                       struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
                        if (rdev
                            && !test_bit(Faulty, &rdev->flags)
                            && !test_bit(In_sync, &rdev->flags)
                            && !rdev_set_badblocks(rdev, sh->sector,
                                                   STRIPE_SECTORS, 0))
                                abort = 1;
-                       rdev = conf->disks[i].replacement;
+                       rdev = rcu_dereference(conf->disks[i].replacement);
                        if (rdev
                            && !test_bit(Faulty, &rdev->flags)
                            && !test_bit(In_sync, &rdev->flags)
@@ -3226,6 +3228,7 @@ handle_failed_sync(struct r5conf *conf, struct stripe_head *sh,
                                                   STRIPE_SECTORS, 0))
                                abort = 1;
                }
+               rcu_read_unlock();
                if (abort)
                        conf->recovery_disabled =
                                conf->mddev->recovery_disabled;
@@ -3237,15 +3240,16 @@ static int want_replace(struct stripe_head *sh, int disk_idx)
 {
        struct md_rdev *rdev;
        int rv = 0;
-       /* Doing recovery so rcu locking not required */
-       rdev = sh->raid_conf->disks[disk_idx].replacement;
+
+       rcu_read_lock();
+       rdev = rcu_dereference(sh->raid_conf->disks[disk_idx].replacement);
        if (rdev
            && !test_bit(Faulty, &rdev->flags)
            && !test_bit(In_sync, &rdev->flags)
            && (rdev->recovery_offset <= sh->sector
                || rdev->mddev->recovery_cp <= sh->sector))
                rv = 1;
-
+       rcu_read_unlock();
        return rv;
 }
 
@@ -3600,7 +3604,7 @@ static void handle_stripe_dirtying(struct r5conf *conf,
        pr_debug("for sector %llu, rmw=%d rcw=%d\n",
                (unsigned long long)sh->sector, rmw, rcw);
        set_bit(STRIPE_HANDLE, &sh->state);
-       if ((rmw < rcw || (rmw == rcw && conf->rmw_level == PARITY_ENABLE_RMW)) && rmw > 0) {
+       if ((rmw < rcw || (rmw == rcw && conf->rmw_level == PARITY_PREFER_RMW)) && rmw > 0) {
                /* prefer read-modify-write, but need to get some data */
                if (conf->mddev->queue)
                        blk_add_trace_msg(conf->mddev->queue,
@@ -3627,7 +3631,7 @@ static void handle_stripe_dirtying(struct r5conf *conf,
                        }
                }
        }
-       if ((rcw < rmw || (rcw == rmw && conf->rmw_level != PARITY_ENABLE_RMW)) && rcw > 0) {
+       if ((rcw < rmw || (rcw == rmw && conf->rmw_level != PARITY_PREFER_RMW)) && rcw > 0) {
                /* want reconstruct write, but need to get some data */
                int qread =0;
                rcw = 0;
@@ -7066,10 +7070,12 @@ static void raid5_status(struct seq_file *seq, struct mddev *mddev)
        seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level,
                conf->chunk_sectors / 2, mddev->layout);
        seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
-       for (i = 0; i < conf->raid_disks; i++)
-               seq_printf (seq, "%s",
-                              conf->disks[i].rdev &&
-                              test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
+       rcu_read_lock();
+       for (i = 0; i < conf->raid_disks; i++) {
+               struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
+               seq_printf (seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
+       }
+       rcu_read_unlock();
        seq_printf (seq, "]");
 }
 
@@ -7191,12 +7197,15 @@ static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
                goto abort;
        }
        *rdevp = NULL;
-       synchronize_rcu();
-       if (atomic_read(&rdev->nr_pending)) {
-               /* lost the race, try later */
-               err = -EBUSY;
-               *rdevp = rdev;
-       } else if (p->replacement) {
+       if (!test_bit(RemoveSynchronized, &rdev->flags)) {
+               synchronize_rcu();
+               if (atomic_read(&rdev->nr_pending)) {
+                       /* lost the race, try later */
+                       err = -EBUSY;
+                       *rdevp = rdev;
+               }
+       }
+       if (p->replacement) {
                /* We must have just cleared 'rdev' */
                p->rdev = p->replacement;
                clear_bit(Replacement, &p->replacement->flags);