dm: refactor dm_suspend completion wait

Move completion wait to separate function

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 27 insertions, 16 deletions

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 11f422ecfda0..9ca012e639a8 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1259,6 +1259,29 @@ void dm_put(struct mapped_device *md)
 }
 EXPORT_SYMBOL_GPL(dm_put);
 
+static int dm_wait_for_completion(struct mapped_device *md)
+{
+        int r = 0;
+
+        while (1) {
+                set_current_state(TASK_INTERRUPTIBLE);
+
+                smp_mb();
+                if (!atomic_read(&md->pending))
+                        break;
+
+                if (signal_pending(current)) {
+                        r = -EINTR;
+                        break;
+                }
+
+                io_schedule();
+        }
+        set_current_state(TASK_RUNNING);
+
+        return r;
+}
+
 /*
  * Process the deferred bios
  */
@@ -1357,7 +1380,7 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
 {
         struct dm_table *map = NULL;
         DECLARE_WAITQUEUE(wait, current);
-        int pending, r = 0;
+        int r = 0;
         int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0;
         int noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG ? 1 : 0;
 
@@ -1414,20 +1437,9 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
                 dm_table_unplug_all(map);
 
         /*
-         * Then we wait for the already mapped ios to
-         * complete.
+         * Wait for the already-mapped ios to complete.
          */
-        while (1) {
-                set_current_state(TASK_INTERRUPTIBLE);
-
-                smp_mb();
-                pending = atomic_read(&md->pending);
-                if (!pending || signal_pending(current))
-                        break;
-
-                io_schedule();
-        }
-        set_current_state(TASK_RUNNING);
+        r = dm_wait_for_completion(md);
 
         down_write(&md->io_lock);
         remove_wait_queue(&md->wait, &wait);
@@ -1437,13 +1449,12 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
         up_write(&md->io_lock);
 
         /* were we interrupted ? */
-        if (pending) {
+        if (r < 0) {
                 down_write(&md->io_lock);
                 __flush_deferred_io(md);
                 up_write(&md->io_lock);
 
                 unlock_fs(md);
-                r = -EINTR;
                 goto out; /* pushback list is already flushed, so skip flush */
         }