libceph: optionally use bounce buffer on recv path in crc mode

[linux-2.6-microblaze.git] / net / ceph / messenger_v2.c

diff --git a/net/ceph/messenger_v2.c b/net/ceph/messenger_v2.c
index 2ea0048..c81379f 100644 (file)
--- a/net/ceph/messenger_v2.c
+++ b/net/ceph/messenger_v2.c
@@ -1753,7 +1753,7 @@ static int prepare_read_control_remainder(struct ceph_connection *con)
        return 0;
 }
 
-static void prepare_read_data(struct ceph_connection *con)
+static int prepare_read_data(struct ceph_connection *con)
 {
        struct bio_vec bv;
 
@@ -1762,23 +1762,55 @@ static void prepare_read_data(struct ceph_connection *con)
                                  data_len(con->in_msg));
 
        get_bvec_at(&con->v2.in_cursor, &bv);
-       set_in_bvec(con, &bv);
+       if (ceph_test_opt(from_msgr(con->msgr), RXBOUNCE)) {
+               if (unlikely(!con->bounce_page)) {
+                       con->bounce_page = alloc_page(GFP_NOIO);
+                       if (!con->bounce_page) {
+                               pr_err("failed to allocate bounce page\n");
+                               return -ENOMEM;
+                       }
+               }
+
+               bv.bv_page = con->bounce_page;
+               bv.bv_offset = 0;
+               set_in_bvec(con, &bv);
+       } else {
+               set_in_bvec(con, &bv);
+       }
        con->v2.in_state = IN_S_PREPARE_READ_DATA_CONT;
+       return 0;
 }
 
 static void prepare_read_data_cont(struct ceph_connection *con)
 {
        struct bio_vec bv;
 
-       con->in_data_crc = ceph_crc32c_page(con->in_data_crc,
-                                           con->v2.in_bvec.bv_page,
-                                           con->v2.in_bvec.bv_offset,
-                                           con->v2.in_bvec.bv_len);
+       if (ceph_test_opt(from_msgr(con->msgr), RXBOUNCE)) {
+               con->in_data_crc = crc32c(con->in_data_crc,
+                                         page_address(con->bounce_page),
+                                         con->v2.in_bvec.bv_len);
+
+               get_bvec_at(&con->v2.in_cursor, &bv);
+               memcpy_to_page(bv.bv_page, bv.bv_offset,
+                              page_address(con->bounce_page),
+                              con->v2.in_bvec.bv_len);
+       } else {
+               con->in_data_crc = ceph_crc32c_page(con->in_data_crc,
+                                                   con->v2.in_bvec.bv_page,
+                                                   con->v2.in_bvec.bv_offset,
+                                                   con->v2.in_bvec.bv_len);
+       }
 
        ceph_msg_data_advance(&con->v2.in_cursor, con->v2.in_bvec.bv_len);
        if (con->v2.in_cursor.total_resid) {
                get_bvec_at(&con->v2.in_cursor, &bv);
-               set_in_bvec(con, &bv);
+               if (ceph_test_opt(from_msgr(con->msgr), RXBOUNCE)) {
+                       bv.bv_page = con->bounce_page;
+                       bv.bv_offset = 0;
+                       set_in_bvec(con, &bv);
+               } else {
+                       set_in_bvec(con, &bv);
+               }
                WARN_ON(con->v2.in_state != IN_S_PREPARE_READ_DATA_CONT);
                return;
        }
@@ -1791,14 +1823,13 @@ static void prepare_read_data_cont(struct ceph_connection *con)
        con->v2.in_state = IN_S_HANDLE_EPILOGUE;
 }
 
-static void prepare_read_tail_plain(struct ceph_connection *con)
+static int prepare_read_tail_plain(struct ceph_connection *con)
 {
        struct ceph_msg *msg = con->in_msg;
 
        if (!front_len(msg) && !middle_len(msg)) {
                WARN_ON(!data_len(msg));
-               prepare_read_data(con);
-               return;
+               return prepare_read_data(con);
        }
 
        reset_in_kvecs(con);
@@ -1817,6 +1848,7 @@ static void prepare_read_tail_plain(struct ceph_connection *con)
                add_in_kvec(con, con->v2.in_buf, CEPH_EPILOGUE_PLAIN_LEN);
                con->v2.in_state = IN_S_HANDLE_EPILOGUE;
        }
+       return 0;
 }
 
 static void prepare_read_enc_page(struct ceph_connection *con)
@@ -2699,8 +2731,7 @@ static int __handle_control(struct ceph_connection *con, void *p)
        if (con_secure(con))
                return prepare_read_tail_secure(con);
 
-       prepare_read_tail_plain(con);
-       return 0;
+       return prepare_read_tail_plain(con);
 }
 
 static int handle_preamble(struct ceph_connection *con)
@@ -2856,8 +2887,7 @@ static int populate_in_iter(struct ceph_connection *con)
                        ret = handle_control_remainder(con);
                        break;
                case IN_S_PREPARE_READ_DATA:
-                       prepare_read_data(con);
-                       ret = 0;
+                       ret = prepare_read_data(con);
                        break;
                case IN_S_PREPARE_READ_DATA_CONT:
                        prepare_read_data_cont(con);