Merge branch 'for-linus' of git://git.kernel.dk/linux-block

Pull xen block driver fixes from Jens Axboe:
 "A few small bug fixes for xen-blk{front,back} that have been sitting
  over my vacation"

* 'for-linus' of git://git.kernel.dk/linux-block:
  xen-blkback: replace work_pending with work_busy in purge_persistent_gnt()
  xen-blkfront: don't add indirect pages to list when !feature_persistent
  xen-blkfront: introduce blkfront_gather_backend_features()

2 files changed, 74 insertions, 58 deletions

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index ced96777b677..954c0029fb3b 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -369,8 +369,8 @@ static void purge_persistent_gnt(struct xen_blkif *blkif)
                 return;
         }
 
-        if (work_pending(&blkif->persistent_purge_work)) {
-                pr_alert_ratelimited("Scheduled work from previous purge is still pending, cannot purge list\n");
+        if (work_busy(&blkif->persistent_purge_work)) {
+                pr_alert_ratelimited("Scheduled work from previous purge is still busy, cannot purge list\n");
                 return;
         }
 
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 6d89ed35d80c..7a8a73f1fc04 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -179,6 +179,7 @@ static DEFINE_SPINLOCK(minor_lock);
         ((_segs + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME)
 
 static int blkfront_setup_indirect(struct blkfront_info *info);
+static int blkfront_gather_backend_features(struct blkfront_info *info);
 
 static int get_id_from_freelist(struct blkfront_info *info)
 {
@@ -1128,8 +1129,10 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
                                  * Add the used indirect page back to the list of
                                  * available pages for indirect grefs.
                                  */
-                                indirect_page = pfn_to_page(s->indirect_grants[i]->pfn);
-                                list_add(&indirect_page->lru, &info->indirect_pages);
+                                if (!info->feature_persistent) {
+                                        indirect_page = pfn_to_page(s->indirect_grants[i]->pfn);
+                                        list_add(&indirect_page->lru, &info->indirect_pages);
+                                }
                                 s->indirect_grants[i]->gref = GRANT_INVALID_REF;
                                 list_add_tail(&s->indirect_grants[i]->node, &info->grants);
                         }
@@ -1519,7 +1522,7 @@ static int blkif_recover(struct blkfront_info *info)
         info->shadow_free = info->ring.req_prod_pvt;
         info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff;
 
-        rc = blkfront_setup_indirect(info);
+        rc = blkfront_gather_backend_features(info);
         if (rc) {
                 kfree(copy);
                 return rc;
@@ -1720,20 +1723,13 @@ static void blkfront_setup_discard(struct blkfront_info *info)
 
 static int blkfront_setup_indirect(struct blkfront_info *info)
 {
-        unsigned int indirect_segments, segs;
+        unsigned int segs;
         int err, i;
 
-        err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
-                            "feature-max-indirect-segments", "%u", &indirect_segments,
-                            NULL);
-        if (err) {
-                info->max_indirect_segments = 0;
+        if (info->max_indirect_segments == 0)
                 segs = BLKIF_MAX_SEGMENTS_PER_REQUEST;
-        } else {
-                info->max_indirect_segments = min(indirect_segments,
-                                                  xen_blkif_max_segments);
+        else
                 segs = info->max_indirect_segments;
-        }
 
         err = fill_grant_buffer(info, (segs + INDIRECT_GREFS(segs)) * BLK_RING_SIZE(info));
         if (err)
@@ -1797,6 +1793,68 @@ out_of_memory:
 }
 
 /*
+ * Gather all backend feature-*
+ */
+static int blkfront_gather_backend_features(struct blkfront_info *info)
+{
+        int err;
+        int barrier, flush, discard, persistent;
+        unsigned int indirect_segments;
+
+        info->feature_flush = 0;
+
+        err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
+                        "feature-barrier", "%d", &barrier,
+                        NULL);
+
+        /*
+         * If there's no "feature-barrier" defined, then it means
+         * we're dealing with a very old backend which writes
+         * synchronously; nothing to do.
+         *
+         * If there are barriers, then we use flush.
+         */
+        if (!err && barrier)
+                info->feature_flush = REQ_FLUSH | REQ_FUA;
+        /*
+         * And if there is "feature-flush-cache" use that above
+         * barriers.
+         */
+        err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
+                        "feature-flush-cache", "%d", &flush,
+                        NULL);
+
+        if (!err && flush)
+                info->feature_flush = REQ_FLUSH;
+
+        err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
+                        "feature-discard", "%d", &discard,
+                        NULL);
+
+        if (!err && discard)
+                blkfront_setup_discard(info);
+
+        err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
+                        "feature-persistent", "%u", &persistent,
+                        NULL);
+        if (err)
+                info->feature_persistent = 0;
+        else
+                info->feature_persistent = persistent;
+
+        err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
+                            "feature-max-indirect-segments", "%u", &indirect_segments,
+                            NULL);
+        if (err)
+                info->max_indirect_segments = 0;
+        else
+                info->max_indirect_segments = min(indirect_segments,
+                                                  xen_blkif_max_segments);
+
+        return blkfront_setup_indirect(info);
+}
+
+/*
  * Invoked when the backend is finally 'ready' (and has told produced
  * the details about the physical device - #sectors, size, etc).
  */
@@ -1807,7 +1865,6 @@ static void blkfront_connect(struct blkfront_info *info)
         unsigned int physical_sector_size;
         unsigned int binfo;
         int err;
-        int barrier, flush, discard, persistent;
 
         switch (info->connected) {
         case BLKIF_STATE_CONNECTED:
@@ -1864,48 +1921,7 @@ static void blkfront_connect(struct blkfront_info *info)
         if (err != 1)
                 physical_sector_size = sector_size;
 
-        info->feature_flush = 0;
-
-        err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
-                            "feature-barrier", "%d", &barrier,
-                            NULL);
-
-        /*
-         * If there's no "feature-barrier" defined, then it means
-         * we're dealing with a very old backend which writes
-         * synchronously; nothing to do.
-         *
-         * If there are barriers, then we use flush.
-         */
-        if (!err && barrier)
-                info->feature_flush = REQ_FLUSH | REQ_FUA;
-        /*
-         * And if there is "feature-flush-cache" use that above
-         * barriers.
-         */
-        err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
-                            "feature-flush-cache", "%d", &flush,
-                            NULL);
-
-        if (!err && flush)
-                info->feature_flush = REQ_FLUSH;
-
-        err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
-                            "feature-discard", "%d", &discard,
-                            NULL);
-
-        if (!err && discard)
-                blkfront_setup_discard(info);
-
-        err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
-                            "feature-persistent", "%u", &persistent,
-                            NULL);
-        if (err)
-                info->feature_persistent = 0;
-        else
-                info->feature_persistent = persistent;
-
-        err = blkfront_setup_indirect(info);
+        err = blkfront_gather_backend_features(info);
         if (err) {
                 xenbus_dev_fatal(info->xbdev, err, "setup_indirect at %s",
                                  info->xbdev->otherend);