drbd: _drbd_send_page(): Return 0 upon success and an error code otherwise

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

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index ff75cce21f402ba4e86ad9625271b2c6e576306e..fa838b24eedfce7ef898a86d4beadff067aeb06e 100644 (file)
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1421,9 +1421,10 @@ static int _drbd_no_send_page(struct drbd_conf *mdev, struct page *page,
 static int _drbd_send_page(struct drbd_conf *mdev, struct page *page,
                    int offset, size_t size, unsigned msg_flags)
 {
+       struct socket *socket = mdev->tconn->data.socket;
        mm_segment_t oldfs = get_fs();
-       int sent, ok;
        int len = size;
+       int err = -EIO;
 
        /* e.g. XFS meta- & log-data is in slab pages, which have a
         * page_count of 0 and/or have PageSlab() set.
@@ -1432,25 +1433,25 @@ static int _drbd_send_page(struct drbd_conf *mdev, struct page *page,
         * __page_cache_release a page that would actually still be referenced
         * by someone, leading to some obscure delayed Oops somewhere else. */
        if (disable_sendpage || (page_count(page) < 1) || PageSlab(page))
-               return !_drbd_no_send_page(mdev, page, offset, size, msg_flags);
+               return _drbd_no_send_page(mdev, page, offset, size, msg_flags);
 
        msg_flags |= MSG_NOSIGNAL;
        drbd_update_congested(mdev->tconn);
        set_fs(KERNEL_DS);
        do {
-               sent = mdev->tconn->data.socket->ops->sendpage(mdev->tconn->data.socket, page,
-                                                       offset, len,
-                                                       msg_flags);
-               if (sent == -EAGAIN) {
-                       if (we_should_drop_the_connection(mdev->tconn,
-                                                         mdev->tconn->data.socket))
-                               break;
-                       else
-                               continue;
-               }
+               int sent;
+
+               sent = socket->ops->sendpage(socket, page, offset, len, msg_flags);
                if (sent <= 0) {
+                       if (sent == -EAGAIN) {
+                               if (we_should_drop_the_connection(mdev->tconn, socket))
+                                       break;
+                               continue;
+                       }
                        dev_warn(DEV, "%s: size=%d len=%d sent=%d\n",
                             __func__, (int)size, len, sent);
+                       if (sent < 0)
+                               err = sent;
                        break;
                }
                len    -= sent;
@@ -1459,10 +1460,11 @@ static int _drbd_send_page(struct drbd_conf *mdev, struct page *page,
        set_fs(oldfs);
        clear_bit(NET_CONGESTED, &mdev->tconn->flags);
 
-       ok = (len == 0);
-       if (likely(ok))
-               mdev->send_cnt += size>>9;
-       return ok;
+       if (len == 0) {
+               err = 0;
+               mdev->send_cnt += size >> 9;
+       }
+       return err;
 }
 
 static int _drbd_send_bio(struct drbd_conf *mdev, struct bio *bio)
@@ -1485,9 +1487,9 @@ static int _drbd_send_zc_bio(struct drbd_conf *mdev, struct bio *bio)
        int i;
        /* hint all but last page with MSG_MORE */
        __bio_for_each_segment(bvec, bio, i, 0) {
-               if (!_drbd_send_page(mdev, bvec->bv_page,
-                                    bvec->bv_offset, bvec->bv_len,
-                                    i == bio->bi_vcnt -1 ? 0 : MSG_MORE))
+               if (_drbd_send_page(mdev, bvec->bv_page,
+                                   bvec->bv_offset, bvec->bv_len,
+                                   i == bio->bi_vcnt -1 ? 0 : MSG_MORE))
                        return 0;
        }
        return 1;
@@ -1502,8 +1504,8 @@ static int _drbd_send_zc_ee(struct drbd_conf *mdev,
        /* hint all but last page with MSG_MORE */
        page_chain_for_each(page) {
                unsigned l = min_t(unsigned, len, PAGE_SIZE);
-               if (!_drbd_send_page(mdev, page, 0, l,
-                               page_chain_next(page) ? MSG_MORE : 0))
+               if (_drbd_send_page(mdev, page, 0, l,
+                                   page_chain_next(page) ? MSG_MORE : 0))
                        return 0;
                len -= l;
        }