9 files changed, 56 insertions, 35 deletions

diff --git a/drivers/md/faulty.c b/drivers/md/faulty.c
index b0536cfd8e17..06a64d5d8c6c 100644
--- a/drivers/md/faulty.c
+++ b/drivers/md/faulty.c
@@ -170,7 +170,7 @@ static void add_sector(struct faulty_conf *conf, sector_t start, int mode)
                 conf->nfaults = n+1;
 }
 
-static void faulty_make_request(struct mddev *mddev, struct bio *bio)
+static bool faulty_make_request(struct mddev *mddev, struct bio *bio)
 {
         struct faulty_conf *conf = mddev->private;
         int failit = 0;
@@ -182,7 +182,7 @@ static void faulty_make_request(struct mddev *mddev, struct bio *bio)
                          * just fail immediately
                          */
                         bio_io_error(bio);
-                        return;
+                        return true;
                 }
 
                 if (check_sector(conf, bio->bi_iter.bi_sector,
@@ -224,6 +224,7 @@ static void faulty_make_request(struct mddev *mddev, struct bio *bio)
                 bio->bi_bdev = conf->rdev->bdev;
 
         generic_make_request(bio);
+        return true;
 }
 
 static void faulty_status(struct seq_file *seq, struct mddev *mddev)
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index df6f2c98eca7..5f1eb9189542 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -245,7 +245,7 @@ static void linear_free(struct mddev *mddev, void *priv)
         kfree(conf);
 }
 
-static void linear_make_request(struct mddev *mddev, struct bio *bio)
+static bool linear_make_request(struct mddev *mddev, struct bio *bio)
 {
         char b[BDEVNAME_SIZE];
         struct dev_info *tmp_dev;
@@ -254,7 +254,7 @@ static void linear_make_request(struct mddev *mddev, struct bio *bio)
 
         if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
                 md_flush_request(mddev, bio);
-                return;
+                return true;
         }
 
         tmp_dev = which_dev(mddev, bio_sector);
@@ -292,7 +292,7 @@ static void linear_make_request(struct mddev *mddev, struct bio *bio)
                 mddev_check_write_zeroes(mddev, bio);
                 generic_make_request(bio);
         }
-        return;
+        return true;
 
 out_of_bounds:
         pr_err("md/linear:%s: make_request: Sector %llu out of bounds on dev %s: %llu sectors, offset %llu\n",
@@ -302,6 +302,7 @@ out_of_bounds:
                (unsigned long long)tmp_dev->rdev->sectors,
                (unsigned long long)start_sector);
         bio_io_error(bio);
+        return true;
 }
 
 static void linear_status (struct seq_file *seq, struct mddev *mddev)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 87edc342ccb3..d7847014821a 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -277,7 +277,7 @@ static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio)
                 bio_endio(bio);
                 return BLK_QC_T_NONE;
         }
-        smp_rmb(); /* Ensure implications of  'active' are visible */
+check_suspended:
         rcu_read_lock();
         if (mddev->suspended) {
                 DEFINE_WAIT(__wait);
@@ -302,7 +302,11 @@ static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio)
         sectors = bio_sectors(bio);
         /* bio could be mergeable after passing to underlayer */
         bio->bi_opf &= ~REQ_NOMERGE;
-        mddev->pers->make_request(mddev, bio);
+        if (!mddev->pers->make_request(mddev, bio)) {
+                atomic_dec(&mddev->active_io);
+                wake_up(&mddev->sb_wait);
+                goto check_suspended;
+        }
 
         cpu = part_stat_lock();
         part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
@@ -327,6 +331,7 @@ void mddev_suspend(struct mddev *mddev)
         if (mddev->suspended++)
                 return;
         synchronize_rcu();
+        wake_up(&mddev->sb_wait);
         wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
         mddev->pers->quiesce(mddev, 1);
 
@@ -7950,12 +7955,14 @@ EXPORT_SYMBOL(md_done_sync);
  * If we need to update some array metadata (e.g. 'active' flag
  * in superblock) before writing, schedule a superblock update
  * and wait for it to complete.
+ * A return value of 'false' means that the write wasn't recorded
+ * and cannot proceed as the array is being suspend.
  */
-void md_write_start(struct mddev *mddev, struct bio *bi)
+bool md_write_start(struct mddev *mddev, struct bio *bi)
 {
         int did_change = 0;
         if (bio_data_dir(bi) != WRITE)
-                return;
+                return true;
 
         BUG_ON(mddev->ro == 1);
         if (mddev->ro == 2) {
@@ -7987,7 +7994,12 @@ void md_write_start(struct mddev *mddev, struct bio *bi)
         if (did_change)
                 sysfs_notify_dirent_safe(mddev->sysfs_state);
         wait_event(mddev->sb_wait,
-                   !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
+                   !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags) && !mddev->suspended);
+        if (test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
+                percpu_ref_put(&mddev->writes_pending);
+                return false;
+        }
+        return true;
 }
 EXPORT_SYMBOL(md_write_start);
 
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 0fa1de42c42b..63d342d560b8 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -510,7 +510,7 @@ struct md_personality
         int level;
         struct list_head list;
         struct module *owner;
-        void (*make_request)(struct mddev *mddev, struct bio *bio);
+        bool (*make_request)(struct mddev *mddev, struct bio *bio);
         int (*run)(struct mddev *mddev);
         void (*free)(struct mddev *mddev, void *priv);
         void (*status)(struct seq_file *seq, struct mddev *mddev);
@@ -649,7 +649,7 @@ extern void md_wakeup_thread(struct md_thread *thread);
 extern void md_check_recovery(struct mddev *mddev);
 extern void md_reap_sync_thread(struct mddev *mddev);
 extern int mddev_init_writes_pending(struct mddev *mddev);
-extern void md_write_start(struct mddev *mddev, struct bio *bi);
+extern bool md_write_start(struct mddev *mddev, struct bio *bi);
 extern void md_write_inc(struct mddev *mddev, struct bio *bi);
 extern void md_write_end(struct mddev *mddev);
 extern void md_done_sync(struct mddev *mddev, int blocks, int ok);
diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c
index e95d521d93e9..c8d985ba008d 100644
--- a/drivers/md/multipath.c
+++ b/drivers/md/multipath.c
@@ -106,7 +106,7 @@ static void multipath_end_request(struct bio *bio)
         rdev_dec_pending(rdev, conf->mddev);
 }
 
-static void multipath_make_request(struct mddev *mddev, struct bio * bio)
+static bool multipath_make_request(struct mddev *mddev, struct bio * bio)
 {
         struct mpconf *conf = mddev->private;
         struct multipath_bh * mp_bh;
@@ -114,7 +114,7 @@ static void multipath_make_request(struct mddev *mddev, struct bio * bio)
 
         if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
                 md_flush_request(mddev, bio);
-                return;
+                return true;
         }
 
         mp_bh = mempool_alloc(conf->pool, GFP_NOIO);
@@ -126,7 +126,7 @@ static void multipath_make_request(struct mddev *mddev, struct bio * bio)
         if (mp_bh->path < 0) {
                 bio_io_error(bio);
                 mempool_free(mp_bh, conf->pool);
-                return;
+                return true;
         }
         multipath = conf->multipaths + mp_bh->path;
 
@@ -141,7 +141,7 @@ static void multipath_make_request(struct mddev *mddev, struct bio * bio)
         mddev_check_writesame(mddev, &mp_bh->bio);
         mddev_check_write_zeroes(mddev, &mp_bh->bio);
         generic_make_request(&mp_bh->bio);
-        return;
+        return true;
 }
 
 static void multipath_status(struct seq_file *seq, struct mddev *mddev)
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index d6c0bc76e837..94d9ae9b0fd0 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -548,7 +548,7 @@ static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
         bio_endio(bio);
 }
 
-static void raid0_make_request(struct mddev *mddev, struct bio *bio)
+static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
 {
         struct strip_zone *zone;
         struct md_rdev *tmp_dev;
@@ -559,12 +559,12 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio)
 
         if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
                 md_flush_request(mddev, bio);
-                return;
+                return true;
         }
 
         if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {
                 raid0_handle_discard(mddev, bio);
-                return;
+                return true;
         }
 
         bio_sector = bio->bi_iter.bi_sector;
@@ -599,6 +599,7 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio)
         mddev_check_writesame(mddev, bio);
         mddev_check_write_zeroes(mddev, bio);
         generic_make_request(bio);
+        return true;
 }
 
 static void raid0_status(struct seq_file *seq, struct mddev *mddev)
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index e1a7e3d4c5e4..c71739b87ab7 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1321,7 +1321,6 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
          * Continue immediately if no resync is active currently.
          */
 
-        md_write_start(mddev, bio); /* wait on superblock update early */
 
         if ((bio_end_sector(bio) > mddev->suspend_lo &&
             bio->bi_iter.bi_sector < mddev->suspend_hi) ||
@@ -1550,13 +1549,13 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
         wake_up(&conf->wait_barrier);
 }
 
-static void raid1_make_request(struct mddev *mddev, struct bio *bio)
+static bool raid1_make_request(struct mddev *mddev, struct bio *bio)
 {
         sector_t sectors;
 
         if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
                 md_flush_request(mddev, bio);
-                return;
+                return true;
         }
 
         /*
@@ -1571,8 +1570,12 @@ static void raid1_make_request(struct mddev *mddev, struct bio *bio)
 
         if (bio_data_dir(bio) == READ)
                 raid1_read_request(mddev, bio, sectors, NULL);
-        else
+        else {
+                if (!md_write_start(mddev,bio))
+                        return false;
                 raid1_write_request(mddev, bio, sectors);
+        }
+        return true;
 }
 
 static void raid1_status(struct seq_file *seq, struct mddev *mddev)
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 797ed60abd5e..52acffa7a06a 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1303,8 +1303,6 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
         sector_t sectors;
         int max_sectors;
 
-        md_write_start(mddev, bio);
-
         /*
          * Register the new request and wait if the reconstruction
          * thread has put up a bar for new requests.
@@ -1525,7 +1523,7 @@ static void __make_request(struct mddev *mddev, struct bio *bio, int sectors)
                 raid10_write_request(mddev, bio, r10_bio);
 }
 
-static void raid10_make_request(struct mddev *mddev, struct bio *bio)
+static bool raid10_make_request(struct mddev *mddev, struct bio *bio)
 {
         struct r10conf *conf = mddev->private;
         sector_t chunk_mask = (conf->geo.chunk_mask & conf->prev.chunk_mask);
@@ -1534,9 +1532,12 @@ static void raid10_make_request(struct mddev *mddev, struct bio *bio)
 
         if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
                 md_flush_request(mddev, bio);
-                return;
+                return true;
         }
 
+        if (!md_write_start(mddev, bio))
+                return false;
+
         /*
          * If this request crosses a chunk boundary, we need to split
          * it.
@@ -1553,6 +1554,7 @@ static void raid10_make_request(struct mddev *mddev, struct bio *bio)
 
         /* In case raid10d snuck in to freeze_array */
         wake_up(&conf->wait_barrier);
+        return true;
 }
 
 static void raid10_status(struct seq_file *seq, struct mddev *mddev)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index ec0f951ae19f..b218a42fd702 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5479,7 +5479,6 @@ static void make_discard_request(struct mddev *mddev, struct bio *bi)
         last_sector = bi->bi_iter.bi_sector + (bi->bi_iter.bi_size>>9);
 
         bi->bi_next = NULL;
-        md_write_start(mddev, bi);
 
         stripe_sectors = conf->chunk_sectors *
                 (conf->raid_disks - conf->max_degraded);
@@ -5549,11 +5548,10 @@ static void make_discard_request(struct mddev *mddev, struct bio *bi)
                 release_stripe_plug(mddev, sh);
         }
 
-        md_write_end(mddev);
         bio_endio(bi);
 }
 
-static void raid5_make_request(struct mddev *mddev, struct bio * bi)
+static bool raid5_make_request(struct mddev *mddev, struct bio * bi)
 {
         struct r5conf *conf = mddev->private;
         int dd_idx;
@@ -5569,10 +5567,10 @@ static void raid5_make_request(struct mddev *mddev, struct bio * bi)
                 int ret = r5l_handle_flush_request(conf->log, bi);
 
                 if (ret == 0)
-                        return;
+                        return true;
                 if (ret == -ENODEV) {
                         md_flush_request(mddev, bi);
-                        return;
+                        return true;
                 }
                 /* ret == -EAGAIN, fallback */
                 /*
@@ -5582,6 +5580,8 @@ static void raid5_make_request(struct mddev *mddev, struct bio * bi)
                 do_flush = bi->bi_opf & REQ_PREFLUSH;
         }
 
+        if (!md_write_start(mddev, bi))
+                return false;
         /*
          * If array is degraded, better not do chunk aligned read because
          * later we might have to read it again in order to reconstruct
@@ -5591,18 +5591,18 @@ static void raid5_make_request(struct mddev *mddev, struct bio * bi)
             mddev->reshape_position == MaxSector) {
                 bi = chunk_aligned_read(mddev, bi);
                 if (!bi)
-                        return;
+                        return true;
         }
 
         if (unlikely(bio_op(bi) == REQ_OP_DISCARD)) {
                 make_discard_request(mddev, bi);
-                return;
+                md_write_end(mddev);
+                return true;
         }
 
         logical_sector = bi->bi_iter.bi_sector & ~((sector_t)STRIPE_SECTORS-1);
         last_sector = bio_end_sector(bi);
         bi->bi_next = NULL;
-        md_write_start(mddev, bi);
 
         prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
         for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
@@ -5740,6 +5740,7 @@ static void raid5_make_request(struct mddev *mddev, struct bio * bi)
         if (rw == WRITE)
                 md_write_end(mddev);
         bio_endio(bi);
+        return true;
 }
 
 static sector_t raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks);