drbd: track meta data IO intent, start and submit time

For diagnostic purposes, track intent, start time
and latest submit time of meta data IO.

Move separate members from struct drbd_device
into the embeded struct drbd_md_io.
s/md_io_(page|in_use)/md_io.\1/

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index d85f43c9ef56..3f8281bbea53 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -542,6 +542,11 @@ struct drbd_backing_dev {
 };
 
 struct drbd_md_io {
+        struct page *page;
+        unsigned long start_jif;        /* last call to drbd_md_get_buffer */
+        unsigned long submit_jif;       /* last _drbd_md_sync_page_io() submit */
+        const char *current_use;
+        atomic_t in_use;
         unsigned int done;
         int error;
 };
@@ -795,9 +800,7 @@ struct drbd_device {
         atomic_t pp_in_use;             /* allocated from page pool */
         atomic_t pp_in_use_by_net;      /* sendpage()d, still referenced by tcp */
         wait_queue_head_t ee_wait;
-        struct page *md_io_page;        /* one page buffer for md_io */
         struct drbd_md_io md_io;
-        atomic_t md_io_in_use;          /* protects the md_io, md_io_page and md_io_tmpp */
         spinlock_t al_lock;
         wait_queue_head_t al_wait;
         struct lru_cache *act_log;      /* activity log */
@@ -1336,7 +1339,7 @@ extern void resume_next_sg(struct drbd_device *device);
 extern void suspend_other_sg(struct drbd_device *device);
 extern int drbd_resync_finished(struct drbd_device *device);
 /* maybe rather drbd_main.c ? */
-extern void *drbd_md_get_buffer(struct drbd_device *device);
+extern void *drbd_md_get_buffer(struct drbd_device *device, const char *intent);
 extern void drbd_md_put_buffer(struct drbd_device *device);
 extern int drbd_md_sync_page_io(struct drbd_device *device,
                 struct drbd_backing_dev *bdev, sector_t sector, int rw);