1 files changed, 59 insertions, 35 deletions
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index f7e6c92f8d03..b5e53695fd7e 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -297,42 +297,48 @@ void drbd_csum_bio(struct drbd_conf *mdev, struct crypto_hash *tfm, struct bio *
        crypto_hash_final(&desc, digest);
 }
-static int w_e_send_csum(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
+/* TODO merge common code with w_e_end_ov_req */
+int w_e_send_csum(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
 {
        struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w);
        int digest_size;
        void *digest;
-        int ok;
+        int ok = 1;
        D_ASSERT(e->block_id == DRBD_MAGIC + 0xbeef);
-        if (unlikely(cancel)) {
+        if (unlikely(cancel))
-                drbd_free_ee(mdev, e);
+                goto out;
-                return 1;
-        }
-        if (likely((e->flags & EE_WAS_ERROR) == 0)) {
+        if (likely((e->flags & EE_WAS_ERROR) != 0))
-                digest_size = crypto_hash_digestsize(mdev->csums_tfm);
+                goto out;
-                digest = kmalloc(digest_size, GFP_NOIO);
-                if (digest) {
-                        drbd_csum_ee(mdev, mdev->csums_tfm, e, digest);
-                        inc_rs_pending(mdev);
+        digest_size = crypto_hash_digestsize(mdev->csums_tfm);
-                        ok = drbd_send_drequest_csum(mdev,
+        digest = kmalloc(digest_size, GFP_NOIO);
-                                                     e->sector,
+        if (digest) {
-                                                     e->size,
+                sector_t sector = e->sector;
-                                                     digest,
+                unsigned int size = e->size;
-                                                     digest_size,
+                drbd_csum_ee(mdev, mdev->csums_tfm, e, digest);
-                                                     P_CSUM_RS_REQUEST);
+                /* Free e and pages before send.
-                        kfree(digest);
+                 * In case we block on congestion, we could otherwise run into
-                } else {
+                 * some distributed deadlock, if the other side blocks on
-                        dev_err(DEV, "kmalloc() of digest failed.\n");
+                 * congestion as well, because our receiver blocks in
-                        ok = 0;
+                 * drbd_pp_alloc due to pp_in_use > max_buffers. */
-                }
+                drbd_free_ee(mdev, e);
-        } else
+                e = NULL;
-                ok = 1;
+                inc_rs_pending(mdev);
+                ok = drbd_send_drequest_csum(mdev, sector, size,
+                                             digest, digest_size,
+                                             P_CSUM_RS_REQUEST);
+                kfree(digest);
+        } else {
+                dev_err(DEV, "kmalloc() of digest failed.\n");
+                ok = 0;
+        }
-        drbd_free_ee(mdev, e);
+out:
+        if (e)
+                drbd_free_ee(mdev, e);
        if (unlikely(!ok))
                dev_err(DEV, "drbd_send_drequest(..., csum) failed\n");
@@ -1071,9 +1077,12 @@ int w_e_end_csum_rs_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
        return ok;
 }
+/* TODO merge common code with w_e_send_csum */
 int w_e_end_ov_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
 {
        struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w);
+        sector_t sector = e->sector;
+        unsigned int size = e->size;
        int digest_size;
        void *digest;
        int ok = 1;
@@ -1093,17 +1102,25 @@ int w_e_end_ov_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
        else
                memset(digest, 0, digest_size);
+        /* Free e and pages before send.
+         * In case we block on congestion, we could otherwise run into
+         * some distributed deadlock, if the other side blocks on
+         * congestion as well, because our receiver blocks in
+         * drbd_pp_alloc due to pp_in_use > max_buffers. */
+        drbd_free_ee(mdev, e);
+        e = NULL;
        inc_rs_pending(mdev);
-        ok = drbd_send_drequest_csum(mdev, e->sector, e->size,
+        ok = drbd_send_drequest_csum(mdev, sector, size,
-                                     digest, digest_size, P_OV_REPLY);
+                                     digest, digest_size,
+                                     P_OV_REPLY);
        if (!ok)
                dec_rs_pending(mdev);
        kfree(digest);
 out:
-        drbd_free_ee(mdev, e);
+        if (e)
+                drbd_free_ee(mdev, e);
        dec_unacked(mdev);
        return ok;
 }
@@ -1122,8 +1139,10 @@ int w_e_end_ov_reply(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
 {
        struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w);
        struct digest_info *di;
-        int digest_size;
        void *digest;
+        sector_t sector = e->sector;
+        unsigned int size = e->size;
+        int digest_size;
        int ok, eq = 0;
        if (unlikely(cancel)) {
@@ -1153,16 +1172,21 @@ int w_e_end_ov_reply(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
                }
        }
-        dec_unacked(mdev);
+                /* Free e and pages before send.
+                 * In case we block on congestion, we could otherwise run into
+                 * some distributed deadlock, if the other side blocks on
+                 * congestion as well, because our receiver blocks in
+                 * drbd_pp_alloc due to pp_in_use > max_buffers. */
+        drbd_free_ee(mdev, e);
        if (!eq)
-                drbd_ov_oos_found(mdev, e->sector, e->size);
+                drbd_ov_oos_found(mdev, sector, size);
        else
                ov_oos_print(mdev);
-        ok = drbd_send_ack_ex(mdev, P_OV_RESULT, e->sector, e->size,
+        ok = drbd_send_ack_ex(mdev, P_OV_RESULT, sector, size,
                              eq ? ID_IN_SYNC : ID_OUT_OF_SYNC);
-        drbd_free_ee(mdev, e);
+        dec_unacked(mdev);
        --mdev->ov_left;