---

yaml
---
r: 346269
b: refs/heads/master
c: edc9f5e
h: refs/heads/master
i:
  346267: 6129121
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e34b677d09ce375a87acd0360537cbed33881b0c
+refs/heads/master: edc9f5eb7afa3d832f540fcfe10e3e1087e6f527

trunk/drivers/block/drbd/drbd_int.h

@@ -682,7 +682,8 @@ enum {
 				   once no more io in flight, start bitmap io */
 	BITMAP_IO_QUEUED,       /* Started bitmap IO */
 	GO_DISKLESS,		/* Disk is being detached, on io-error or admin request. */
-	WAS_IO_ERROR,		/* Local disk failed returned IO error */
+	WAS_IO_ERROR,		/* Local disk failed, returned IO error */
+	WAS_READ_ERROR,		/* Local disk READ failed (set additionally to the above) */
 	FORCE_DETACH,		/* Force-detach from local disk, aborting any pending local IO */
 	RESYNC_AFTER_NEG,       /* Resync after online grow after the attach&negotiate finished. */
 	RESIZE_PENDING,		/* Size change detected locally, waiting for the response from
@@ -1142,6 +1143,9 @@ extern void drbd_queue_bitmap_io(struct drbd_conf *mdev,
 extern int drbd_bitmap_io(struct drbd_conf *mdev,
 		int (*io_fn)(struct drbd_conf *),
 		char *why, enum bm_flag flags);
+extern int drbd_bitmap_io_from_worker(struct drbd_conf *mdev,
+		int (*io_fn)(struct drbd_conf *),
+		char *why, enum bm_flag flags);
 extern int drbd_bmio_set_n_write(struct drbd_conf *mdev);
 extern int drbd_bmio_clear_n_write(struct drbd_conf *mdev);
 extern void drbd_go_diskless(struct drbd_conf *mdev);
@@ -1661,14 +1665,15 @@ static inline union drbd_state drbd_read_state(struct drbd_conf *mdev)
 }
 
 enum drbd_force_detach_flags {
-	DRBD_IO_ERROR,
+	DRBD_READ_ERROR,
+	DRBD_WRITE_ERROR,
 	DRBD_META_IO_ERROR,
 	DRBD_FORCE_DETACH,
 };
 
 #define __drbd_chk_io_error(m,f) __drbd_chk_io_error_(m,f, __func__)
 static inline void __drbd_chk_io_error_(struct drbd_conf *mdev,
-		enum drbd_force_detach_flags forcedetach,
+		enum drbd_force_detach_flags df,
 		const char *where)
 {
 	enum drbd_io_error_p ep;
@@ -1678,18 +1683,40 @@ static inline void __drbd_chk_io_error_(struct drbd_conf *mdev,
 	rcu_read_unlock();
 	switch (ep) {
 	case EP_PASS_ON: /* FIXME would this be better named "Ignore"? */
-		if (forcedetach == DRBD_IO_ERROR) {
+		if (df == DRBD_READ_ERROR || df == DRBD_WRITE_ERROR) {
 			if (__ratelimit(&drbd_ratelimit_state))
 				dev_err(DEV, "Local IO failed in %s.\n", where);
 			if (mdev->state.disk > D_INCONSISTENT)
 				_drbd_set_state(_NS(mdev, disk, D_INCONSISTENT), CS_HARD, NULL);
 			break;
 		}
-		/* NOTE fall through to detach case if forcedetach set */
+		/* NOTE fall through for DRBD_META_IO_ERROR or DRBD_FORCE_DETACH */
 	case EP_DETACH:
 	case EP_CALL_HELPER:
+		/* Remember whether we saw a READ or WRITE error.
+		 *
+		 * Recovery of the affected area for WRITE failure is covered
+		 * by the activity log.
+		 * READ errors may fall outside that area though. Certain READ
+		 * errors can be "healed" by writing good data to the affected
+		 * blocks, which triggers block re-allocation in lower layers.
+		 *
+		 * If we can not write the bitmap after a READ error,
+		 * we may need to trigger a full sync (see w_go_diskless()).
+		 *
+		 * Force-detach is not really an IO error, but rather a
+		 * desperate measure to try to deal with a completely
+		 * unresponsive lower level IO stack.
+		 * Still it should be treated as a WRITE error.
+		 *
+		 * Meta IO error is always WRITE error:
+		 * we read meta data only once during attach,
+		 * which will fail in case of errors.
+		 */
 		set_bit(WAS_IO_ERROR, &mdev->flags);
-		if (forcedetach == DRBD_FORCE_DETACH)
+		if (df == DRBD_READ_ERROR)
+			set_bit(WAS_READ_ERROR, &mdev->flags);
+		if (df == DRBD_FORCE_DETACH)
 			set_bit(FORCE_DETACH, &mdev->flags);
 		if (mdev->state.disk > D_FAILED) {
 			_drbd_set_state(_NS(mdev, disk, D_FAILED), CS_HARD, NULL);

trunk/drivers/block/drbd/drbd_main.c

@@ -3226,6 +3226,26 @@ static int w_go_diskless(struct drbd_work *w, int unused)
 	 * inc/dec it frequently. Once we are D_DISKLESS, no one will touch
 	 * the protected members anymore, though, so once put_ldev reaches zero
 	 * again, it will be safe to free them. */
+
+	/* Try to write changed bitmap pages, read errors may have just
+	 * set some bits outside the area covered by the activity log.
+	 *
+	 * If we have an IO error during the bitmap writeout,
+	 * we will want a full sync next time, just in case.
+	 * (Do we want a specific meta data flag for this?)
+	 *
+	 * If that does not make it to stable storage either,
+	 * we cannot do anything about that anymore.  */
+	if (mdev->bitmap) {
+		if (drbd_bitmap_io_from_worker(mdev, drbd_bm_write,
+					"detach", BM_LOCKED_MASK)) {
+			if (test_bit(WAS_READ_ERROR, &mdev->flags)) {
+				drbd_md_set_flag(mdev, MDF_FULL_SYNC);
+				drbd_md_sync(mdev);
+			}
+		}
+	}
+
 	drbd_force_state(mdev, NS(disk, D_DISKLESS));
 	return 0;
 }

trunk/drivers/block/drbd/drbd_nl.c

@@ -1294,6 +1294,8 @@ int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info)
 
 	/* make sure there is no leftover from previous force-detach attempts */
 	clear_bit(FORCE_DETACH, &mdev->flags);
+	clear_bit(WAS_IO_ERROR, &mdev->flags);
+	clear_bit(WAS_READ_ERROR, &mdev->flags);
 
 	/* and no leftover from previously aborted resync or verify, either */
 	mdev->rs_total = 0;

trunk/drivers/block/drbd/drbd_req.c

@@ -492,11 +492,14 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what,
 		mod_rq_state(req, m, 0, RQ_LOCAL_ABORTED);
 		break;
 
+	case WRITE_COMPLETED_WITH_ERROR:
+		__drbd_chk_io_error(mdev, DRBD_WRITE_ERROR);
+		mod_rq_state(req, m, RQ_LOCAL_PENDING, RQ_LOCAL_COMPLETED);
+		break;
+
 	case READ_COMPLETED_WITH_ERROR:
 		drbd_set_out_of_sync(mdev, req->i.sector, req->i.size);
-		/* fall through. */
-	case WRITE_COMPLETED_WITH_ERROR:
-		__drbd_chk_io_error(mdev, DRBD_IO_ERROR);
+		__drbd_chk_io_error(mdev, DRBD_READ_ERROR);
 		/* fall through. */
 	case READ_AHEAD_COMPLETED_WITH_ERROR:
 		/* it is legal to fail READA, no __drbd_chk_io_error in that case. */

trunk/drivers/block/drbd/drbd_worker.c

@@ -106,7 +106,7 @@ void drbd_endio_read_sec_final(struct drbd_peer_request *peer_req) __releases(lo
 	if (list_empty(&mdev->read_ee))
 		wake_up(&mdev->ee_wait);
 	if (test_bit(__EE_WAS_ERROR, &peer_req->flags))
-		__drbd_chk_io_error(mdev, DRBD_IO_ERROR);
+		__drbd_chk_io_error(mdev, DRBD_READ_ERROR);
 	spin_unlock_irqrestore(&mdev->tconn->req_lock, flags);
 
 	drbd_queue_work(&mdev->tconn->sender_work, &peer_req->w);
@@ -147,7 +147,7 @@ static void drbd_endio_write_sec_final(struct drbd_peer_request *peer_req) __rel
 	do_wake = list_empty(block_id == ID_SYNCER ? &mdev->sync_ee : &mdev->active_ee);
 
 	if (test_bit(__EE_WAS_ERROR, &peer_req->flags))
-		__drbd_chk_io_error(mdev, DRBD_IO_ERROR);
+		__drbd_chk_io_error(mdev, DRBD_WRITE_ERROR);
 	spin_unlock_irqrestore(&mdev->tconn->req_lock, flags);
 
 	if (block_id == ID_SYNCER)