1 files changed, 137 insertions, 31 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 04f4f131f9d6..24638ccedce4 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -37,6 +37,7 @@
 
 */
 
+#include <linux/sched/mm.h>
 #include <linux/sched/signal.h>
 #include <linux/kthread.h>
 #include <linux/blkdev.h>
@@ -124,6 +125,77 @@ static inline int speed_max(struct mddev *mddev)
 		mddev->sync_speed_max : sysctl_speed_limit_max;
 }
 
+static int rdev_init_wb(struct md_rdev *rdev)
+{
+	if (rdev->bdev->bd_queue->nr_hw_queues == 1)
+		return 0;
+
+	spin_lock_init(&rdev->wb_list_lock);
+	INIT_LIST_HEAD(&rdev->wb_list);
+	init_waitqueue_head(&rdev->wb_io_wait);
+	set_bit(WBCollisionCheck, &rdev->flags);
+
+	return 1;
+}
+
+/*
+ * Create wb_info_pool if rdev is the first multi-queue device flaged
+ * with writemostly, also write-behind mode is enabled.
+ */
+void mddev_create_wb_pool(struct mddev *mddev, struct md_rdev *rdev,
+			  bool is_suspend)
+{
+	if (mddev->bitmap_info.max_write_behind == 0)
+		return;
+
+	if (!test_bit(WriteMostly, &rdev->flags) || !rdev_init_wb(rdev))
+		return;
+
+	if (mddev->wb_info_pool == NULL) {
+		unsigned int noio_flag;
+
+		if (!is_suspend)
+			mddev_suspend(mddev);
+		noio_flag = memalloc_noio_save();
+		mddev->wb_info_pool = mempool_create_kmalloc_pool(NR_WB_INFOS,
+							sizeof(struct wb_info));
+		memalloc_noio_restore(noio_flag);
+		if (!mddev->wb_info_pool)
+			pr_err("can't alloc memory pool for writemostly\n");
+		if (!is_suspend)
+			mddev_resume(mddev);
+	}
+}
+EXPORT_SYMBOL_GPL(mddev_create_wb_pool);
+
+/*
+ * destroy wb_info_pool if rdev is the last device flaged with WBCollisionCheck.
+ */
+static void mddev_destroy_wb_pool(struct mddev *mddev, struct md_rdev *rdev)
+{
+	if (!test_and_clear_bit(WBCollisionCheck, &rdev->flags))
+		return;
+
+	if (mddev->wb_info_pool) {
+		struct md_rdev *temp;
+		int num = 0;
+
+		/*
+		 * Check if other rdevs need wb_info_pool.
+		 */
+		rdev_for_each(temp, mddev)
+			if (temp != rdev &&
+			    test_bit(WBCollisionCheck, &temp->flags))
+				num++;
+		if (!num) {
+			mddev_suspend(rdev->mddev);
+			mempool_destroy(mddev->wb_info_pool);
+			mddev->wb_info_pool = NULL;
+			mddev_resume(rdev->mddev);
+		}
+	}
+}
+
 static struct ctl_table_header *raid_table_header;
 
 static struct ctl_table raid_table[] = {
@@ -2210,6 +2282,9 @@ static int bind_rdev_to_array(struct md_rdev *rdev, struct mddev *mddev)
 	rdev->mddev = mddev;
 	pr_debug("md: bind<%s>\n", b);
 
+	if (mddev->raid_disks)
+		mddev_create_wb_pool(mddev, rdev, false);
+
 	if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
 		goto fail;
 
@@ -2246,6 +2321,7 @@ static void unbind_rdev_from_array(struct md_rdev *rdev)
 	bd_unlink_disk_holder(rdev->bdev, rdev->mddev->gendisk);
 	list_del_rcu(&rdev->same_set);
 	pr_debug("md: unbind<%s>\n", bdevname(rdev->bdev,b));
+	mddev_destroy_wb_pool(rdev->mddev, rdev);
 	rdev->mddev = NULL;
 	sysfs_remove_link(&rdev->kobj, "block");
 	sysfs_put(rdev->sysfs_state);
@@ -2758,8 +2834,10 @@ state_store(struct md_rdev *rdev, const char *buf, size_t len)
 		}
 	} else if (cmd_match(buf, "writemostly")) {
 		set_bit(WriteMostly, &rdev->flags);
+		mddev_create_wb_pool(rdev->mddev, rdev, false);
 		err = 0;
 	} else if (cmd_match(buf, "-writemostly")) {
+		mddev_destroy_wb_pool(rdev->mddev, rdev);
 		clear_bit(WriteMostly, &rdev->flags);
 		err = 0;
 	} else if (cmd_match(buf, "blocked")) {
@@ -3356,7 +3434,7 @@ rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
 	if (!entry->show)
 		return -EIO;
 	if (!rdev->mddev)
-		return -EBUSY;
+		return -ENODEV;
 	return entry->show(rdev, page);
 }
 
@@ -5238,7 +5316,8 @@ int mddev_init_writes_pending(struct mddev *mddev)
 {
 	if (mddev->writes_pending.percpu_count_ptr)
 		return 0;
-	if (percpu_ref_init(&mddev->writes_pending, no_op, 0, GFP_KERNEL) < 0)
+	if (percpu_ref_init(&mddev->writes_pending, no_op,
+			    PERCPU_REF_ALLOW_REINIT, GFP_KERNEL) < 0)
 		return -ENOMEM;
 	/* We want to start with the refcount at zero */
 	percpu_ref_put(&mddev->writes_pending);
@@ -5588,15 +5667,28 @@ int md_run(struct mddev *mddev)
 			mddev->bitmap = bitmap;
 
 	}
-	if (err) {
-		mddev_detach(mddev);
-		if (mddev->private)
-			pers->free(mddev, mddev->private);
-		mddev->private = NULL;
-		module_put(pers->owner);
-		md_bitmap_destroy(mddev);
-		goto abort;
+	if (err)
+		goto bitmap_abort;
+
+	if (mddev->bitmap_info.max_write_behind > 0) {
+		bool creat_pool = false;
+
+		rdev_for_each(rdev, mddev) {
+			if (test_bit(WriteMostly, &rdev->flags) &&
+			    rdev_init_wb(rdev))
+				creat_pool = true;
+		}
+		if (creat_pool && mddev->wb_info_pool == NULL) {
+			mddev->wb_info_pool =
+				mempool_create_kmalloc_pool(NR_WB_INFOS,
+						    sizeof(struct wb_info));
+			if (!mddev->wb_info_pool) {
+				err = -ENOMEM;
+				goto bitmap_abort;
+			}
+		}
 	}
+
 	if (mddev->queue) {
 		bool nonrot = true;
 
@@ -5639,8 +5731,7 @@ int md_run(struct mddev *mddev)
 	spin_unlock(&mddev->lock);
 	rdev_for_each(rdev, mddev)
 		if (rdev->raid_disk >= 0)
-			if (sysfs_link_rdev(mddev, rdev))
-				/* failure here is OK */;
+			sysfs_link_rdev(mddev, rdev); /* failure here is OK */
 
 	if (mddev->degraded && !mddev->ro)
 		/* This ensures that recovering status is reported immediately
@@ -5658,6 +5749,13 @@ int md_run(struct mddev *mddev)
 	sysfs_notify(&mddev->kobj, NULL, "degraded");
 	return 0;
 
+bitmap_abort:
+	mddev_detach(mddev);
+	if (mddev->private)
+		pers->free(mddev, mddev->private);
+	mddev->private = NULL;
+	module_put(pers->owner);
+	md_bitmap_destroy(mddev);
 abort:
 	bioset_exit(&mddev->bio_set);
 	bioset_exit(&mddev->sync_set);
@@ -5826,6 +5924,8 @@ static void __md_stop_writes(struct mddev *mddev)
 			mddev->in_sync = 1;
 		md_update_sb(mddev, 1);
 	}
+	mempool_destroy(mddev->wb_info_pool);
+	mddev->wb_info_pool = NULL;
 }
 
 void md_stop_writes(struct mddev *mddev)
@@ -7607,9 +7707,9 @@ static void status_unused(struct seq_file *seq)
 static int status_resync(struct seq_file *seq, struct mddev *mddev)
 {
 	sector_t max_sectors, resync, res;
-	unsigned long dt, db;
-	sector_t rt;
-	int scale;
+	unsigned long dt, db = 0;
+	sector_t rt, curr_mark_cnt, resync_mark_cnt;
+	int scale, recovery_active;
 	unsigned int per_milli;
 
 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
@@ -7698,22 +7798,30 @@ static int status_resync(struct seq_file *seq, struct mddev *mddev)
 	 * db: blocks written from mark until now
 	 * rt: remaining time
 	 *
-	 * rt is a sector_t, so could be 32bit or 64bit.
-	 * So we divide before multiply in case it is 32bit and close
-	 * to the limit.
-	 * We scale the divisor (db) by 32 to avoid losing precision
-	 * near the end of resync when the number of remaining sectors
-	 * is close to 'db'.
-	 * We then divide rt by 32 after multiplying by db to compensate.
-	 * The '+1' avoids division by zero if db is very small.
+	 * rt is a sector_t, which is always 64bit now. We are keeping
+	 * the original algorithm, but it is not really necessary.
+	 *
+	 * Original algorithm:
+	 *   So we divide before multiply in case it is 32bit and close
+	 *   to the limit.
+	 *   We scale the divisor (db) by 32 to avoid losing precision
+	 *   near the end of resync when the number of remaining sectors
+	 *   is close to 'db'.
+	 *   We then divide rt by 32 after multiplying by db to compensate.
+	 *   The '+1' avoids division by zero if db is very small.
 	 */
 	dt = ((jiffies - mddev->resync_mark) / HZ);
 	if (!dt) dt++;
-	db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
-		- mddev->resync_mark_cnt;
+
+	curr_mark_cnt = mddev->curr_mark_cnt;
+	recovery_active = atomic_read(&mddev->recovery_active);
+	resync_mark_cnt = mddev->resync_mark_cnt;
+
+	if (curr_mark_cnt >= (recovery_active + resync_mark_cnt))
+		db = curr_mark_cnt - (recovery_active + resync_mark_cnt);
 
 	rt = max_sectors - resync;    /* number of remaining sectors */
-	sector_div(rt, db/32+1);
+	rt = div64_u64(rt, db/32+1);
 	rt *= dt;
 	rt >>= 5;
 
@@ -8190,8 +8298,7 @@ void md_do_sync(struct md_thread *thread)
 {
 	struct mddev *mddev = thread->mddev;
 	struct mddev *mddev2;
-	unsigned int currspeed = 0,
-		 window;
+	unsigned int currspeed = 0, window;
 	sector_t max_sectors,j, io_sectors, recovery_done;
 	unsigned long mark[SYNC_MARKS];
 	unsigned long update_time;
@@ -8248,7 +8355,7 @@ void md_do_sync(struct md_thread *thread)
 	 * 0 == not engaged in resync at all
 	 * 2 == checking that there is no conflict with another sync
 	 * 1 == like 2, but have yielded to allow conflicting resync to
-	 *		commense
+	 *		commence
 	 * other == active in resync - this many blocks
 	 *
 	 * Before starting a resync we must have set curr_resync to
@@ -8379,7 +8486,7 @@ void md_do_sync(struct md_thread *thread)
 	/*
 	 * Tune reconstruction:
 	 */
-	window = 32*(PAGE_SIZE/512);
+	window = 32 * (PAGE_SIZE / 512);
 	pr_debug("md: using %dk window, over a total of %lluk.\n",
 		 window/2, (unsigned long long)max_sectors/2);
 
@@ -9192,7 +9299,6 @@ static void check_sb_changes(struct mddev *mddev, struct md_rdev *rdev)
 				 * perform resync with the new activated disk */
 				set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 				md_wakeup_thread(mddev->thread);
-
 			}
 			/* device faulty
 			 * We just want to do the minimum to mark the disk