md: factor out a helper rdev_removeable() from remove_and_add_spares()

There are no functional changes, just to make the code simpler and
prepare to delay remove_and_add_spares() to md_start_sync().

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230825031622.1530464-5-yukuai1@huaweicloud.com

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 52fe795f9011b4eb230def6834cdaf630f16f292..3118ab26cef66b1acb0c67b1cc4ab7a7bfebb46e 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -9164,6 +9164,42 @@ void md_do_sync(struct md_thread *thread)
 }
 EXPORT_SYMBOL_GPL(md_do_sync);
 
+static bool rdev_removeable(struct md_rdev *rdev)
+{
+       /* rdev is not used. */
+       if (rdev->raid_disk < 0)
+               return false;
+
+       /* There are still inflight io, don't remove this rdev. */
+       if (atomic_read(&rdev->nr_pending))
+               return false;
+
+       /*
+        * An error occurred but has not yet been acknowledged by the metadata
+        * handler, don't remove this rdev.
+        */
+       if (test_bit(Blocked, &rdev->flags))
+               return false;
+
+       /* Fautly rdev is not used, it's safe to remove it. */
+       if (test_bit(Faulty, &rdev->flags))
+               return true;
+
+       /* Journal disk can only be removed if it's faulty. */
+       if (test_bit(Journal, &rdev->flags))
+               return false;
+
+       /*
+        * 'In_sync' is cleared while 'raid_disk' is valid, which means
+        * replacement has just become active from pers->spare_active(), and
+        * then pers->hot_remove_disk() will replace this rdev with replacement.
+        */
+       if (!test_bit(In_sync, &rdev->flags))
+               return true;
+
+       return false;
+}
+
 static int remove_and_add_spares(struct mddev *mddev,
                                 struct md_rdev *this)
 {
@@ -9196,12 +9232,8 @@ static int remove_and_add_spares(struct mddev *mddev,
                synchronize_rcu();
        rdev_for_each(rdev, mddev) {
                if ((this == NULL || rdev == this) &&
-                   rdev->raid_disk >= 0 &&
-                   !test_bit(Blocked, &rdev->flags) &&
-                   ((test_bit(RemoveSynchronized, &rdev->flags) ||
-                    (!test_bit(In_sync, &rdev->flags) &&
-                     !test_bit(Journal, &rdev->flags))) &&
-                   atomic_read(&rdev->nr_pending)==0)) {
+                   (test_bit(RemoveSynchronized, &rdev->flags) ||
+                    rdev_removeable(rdev))) {
                        if (mddev->pers->hot_remove_disk(
                                    mddev, rdev) == 0) {
                                sysfs_unlink_rdev(mddev, rdev);