1 files changed, 62 insertions, 22 deletions

diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c
index e5d89f623b90..ab62b81c2ca7 100644
--- a/drivers/block/drbd/drbd_bitmap.c
+++ b/drivers/block/drbd/drbd_bitmap.c
@@ -96,6 +96,13 @@ struct drbd_bitmap {
         struct page **bm_pages;
         spinlock_t bm_lock;
 
+        /* exclusively to be used by __al_write_transaction(),
+         * drbd_bm_mark_for_writeout() and
+         * and drbd_bm_write_hinted() -> bm_rw() called from there.
+         */
+        unsigned int n_bitmap_hints;
+        unsigned int al_bitmap_hints[AL_UPDATES_PER_TRANSACTION];
+
         /* see LIMITATIONS: above */
 
         unsigned long bm_set;       /* nr of set bits; THINK maybe atomic_t? */
@@ -242,6 +249,11 @@ static void bm_set_page_need_writeout(struct page *page)
         set_bit(BM_PAGE_NEED_WRITEOUT, &page_private(page));
 }
 
+void drbd_bm_reset_al_hints(struct drbd_device *device)
+{
+        device->bitmap->n_bitmap_hints = 0;
+}
+
 /**
  * drbd_bm_mark_for_writeout() - mark a page with a "hint" to be considered for writeout
  * @device:     DRBD device.
@@ -253,6 +265,7 @@ static void bm_set_page_need_writeout(struct page *page)
  */
 void drbd_bm_mark_for_writeout(struct drbd_device *device, int page_nr)
 {
+        struct drbd_bitmap *b = device->bitmap;
         struct page *page;
         if (page_nr >= device->bitmap->bm_number_of_pages) {
                 drbd_warn(device, "BAD: page_nr: %u, number_of_pages: %u\n",
@@ -260,7 +273,9 @@ void drbd_bm_mark_for_writeout(struct drbd_device *device, int page_nr)
                 return;
         }
         page = device->bitmap->bm_pages[page_nr];
-        set_bit(BM_PAGE_HINT_WRITEOUT, &page_private(page));
+        BUG_ON(b->n_bitmap_hints >= ARRAY_SIZE(b->al_bitmap_hints));
+        if (!test_and_set_bit(BM_PAGE_HINT_WRITEOUT, &page_private(page)))
+                b->al_bitmap_hints[b->n_bitmap_hints++] = page_nr;
 }
 
 static int bm_test_page_unchanged(struct page *page)
@@ -427,8 +442,7 @@ static struct page **bm_realloc_pages(struct drbd_bitmap *b, unsigned long want)
 }
 
 /*
- * called on driver init only. TODO call when a device is created.
- * allocates the drbd_bitmap, and stores it in device->bitmap.
+ * allocates the drbd_bitmap and stores it in device->bitmap.
  */
 int drbd_bm_init(struct drbd_device *device)
 {
@@ -633,7 +647,8 @@ int drbd_bm_resize(struct drbd_device *device, sector_t capacity, int set_new_bi
         unsigned long bits, words, owords, obits;
         unsigned long want, have, onpages; /* number of pages */
         struct page **npages, **opages = NULL;
-        int err = 0, growing;
+        int err = 0;
+        bool growing;
 
         if (!expect(b))
                 return -ENOMEM;
@@ -1030,7 +1045,7 @@ static int bm_rw(struct drbd_device *device, const unsigned int flags, unsigned
 {
         struct drbd_bm_aio_ctx *ctx;
         struct drbd_bitmap *b = device->bitmap;
-        int num_pages, i, count = 0;
+        unsigned int num_pages, i, count = 0;
         unsigned long now;
         char ppb[10];
         int err = 0;
@@ -1078,16 +1093,37 @@ static int bm_rw(struct drbd_device *device, const unsigned int flags, unsigned
         now = jiffies;
 
         /* let the layers below us try to merge these bios... */
-        for (i = 0; i < num_pages; i++) {
-                /* ignore completely unchanged pages */
-                if (lazy_writeout_upper_idx && i == lazy_writeout_upper_idx)
-                        break;
-                if (!(flags & BM_AIO_READ)) {
-                        if ((flags & BM_AIO_WRITE_HINTED) &&
-                            !test_and_clear_bit(BM_PAGE_HINT_WRITEOUT,
-                                    &page_private(b->bm_pages[i])))
-                                continue;
 
+        if (flags & BM_AIO_READ) {
+                for (i = 0; i < num_pages; i++) {
+                        atomic_inc(&ctx->in_flight);
+                        bm_page_io_async(ctx, i);
+                        ++count;
+                        cond_resched();
+                }
+        } else if (flags & BM_AIO_WRITE_HINTED) {
+                /* ASSERT: BM_AIO_WRITE_ALL_PAGES is not set. */
+                unsigned int hint;
+                for (hint = 0; hint < b->n_bitmap_hints; hint++) {
+                        i = b->al_bitmap_hints[hint];
+                        if (i >= num_pages) /* == -1U: no hint here. */
+                                continue;
+                        /* Several AL-extents may point to the same page. */
+                        if (!test_and_clear_bit(BM_PAGE_HINT_WRITEOUT,
+                            &page_private(b->bm_pages[i])))
+                                continue;
+                        /* Has it even changed? */
+                        if (bm_test_page_unchanged(b->bm_pages[i]))
+                                continue;
+                        atomic_inc(&ctx->in_flight);
+                        bm_page_io_async(ctx, i);
+                        ++count;
+                }
+        } else {
+                for (i = 0; i < num_pages; i++) {
+                        /* ignore completely unchanged pages */
+                        if (lazy_writeout_upper_idx && i == lazy_writeout_upper_idx)
+                                break;
                         if (!(flags & BM_AIO_WRITE_ALL_PAGES) &&
                             bm_test_page_unchanged(b->bm_pages[i])) {
                                 dynamic_drbd_dbg(device, "skipped bm write for idx %u\n", i);
@@ -1100,11 +1136,11 @@ static int bm_rw(struct drbd_device *device, const unsigned int flags, unsigned
                                 dynamic_drbd_dbg(device, "skipped bm lazy write for idx %u\n", i);
                                 continue;
                         }
+                        atomic_inc(&ctx->in_flight);
+                        bm_page_io_async(ctx, i);
+                        ++count;
+                        cond_resched();
                 }
-                atomic_inc(&ctx->in_flight);
-                bm_page_io_async(ctx, i);
-                ++count;
-                cond_resched();
         }
 
         /*
@@ -1121,10 +1157,14 @@ static int bm_rw(struct drbd_device *device, const unsigned int flags, unsigned
                 kref_put(&ctx->kref, &drbd_bm_aio_ctx_destroy);
 
         /* summary for global bitmap IO */
-        if (flags == 0)
-                drbd_info(device, "bitmap %s of %u pages took %lu jiffies\n",
-                         (flags & BM_AIO_READ) ? "READ" : "WRITE",
-                         count, jiffies - now);
+        if (flags == 0) {
+                unsigned int ms = jiffies_to_msecs(jiffies - now);
+                if (ms > 5) {
+                        drbd_info(device, "bitmap %s of %u pages took %u ms\n",
+                                 (flags & BM_AIO_READ) ? "READ" : "WRITE",
+                                 count, ms);
+                }
+        }
 
         if (ctx->error) {
                 drbd_alert(device, "we had at least one MD IO ERROR during bitmap IO\n");