libceph: distinguish page array and pagelist count

Use distinct fields for tracking the number of pages in a message's
page array and in a message's page list.  Currently only one or the
other is used at a time, but that will be changing soon.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

4 files changed, 14 insertions, 11 deletions

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 442880d099c9..5c17705f88b1 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -1719,7 +1719,7 @@ static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
 
         msg->pages = req->r_pages;
-        msg->nr_pages = req->r_num_pages;
+        msg->page_count = req->r_num_pages;
         msg->hdr.data_len = cpu_to_le32(req->r_data_len);
         msg->hdr.data_off = cpu_to_le16(0);
 
@@ -2600,10 +2600,10 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc,
         }
 
         reply->pagelist = pagelist;
+        reply->pagelist_count = calc_pages_for(0, pagelist->length);
         if (recon_state.flock)
                 reply->hdr.version = cpu_to_le16(2);
         reply->hdr.data_len = cpu_to_le32(pagelist->length);
-        reply->nr_pages = calc_pages_for(0, pagelist->length);
         ceph_con_send(&session->s_con, reply);
 
         mutex_unlock(&session->s_mutex);
diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h
index 8297288a66e0..1b08349a413c 100644
--- a/include/linux/ceph/messenger.h
+++ b/include/linux/ceph/messenger.h
@@ -75,9 +75,10 @@ struct ceph_msg {
         struct kvec front;              /* unaligned blobs of message */
         struct ceph_buffer *middle;
         struct page **pages;            /* data payload.  NOT OWNER. */
-        unsigned nr_pages;              /* size of page array */
+        unsigned page_count;            /* size of page array */
         unsigned page_alignment;        /* io offset in first page */
         struct ceph_pagelist *pagelist; /* instead of pages */
+        unsigned int pagelist_count;    /* number of pages in pagelist */
 
         struct ceph_connection *con;
         struct list_head list_head;
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index c06f94009d73..9d8abb0a7cef 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -813,7 +813,7 @@ static void prepare_write_message(struct ceph_connection *con)
              m, con->out_seq, le16_to_cpu(m->hdr.type),
              le32_to_cpu(m->hdr.front_len), le32_to_cpu(m->hdr.middle_len),
              le32_to_cpu(m->hdr.data_len),
-             m->nr_pages);
+             m->page_count);
         BUG_ON(le32_to_cpu(m->hdr.front_len) != m->front.iov_len);
 
         /* tag + hdr + front + middle */
@@ -1072,7 +1072,7 @@ static int write_partial_msg_pages(struct ceph_connection *con)
         const size_t trail_off = data_len - trail_len;
 
         dout("write_partial_msg_pages %p msg %p page %d/%d offset %d\n",
-             con, msg, con->out_msg_pos.page, msg->nr_pages,
+             con, msg, con->out_msg_pos.page, msg->page_count,
              con->out_msg_pos.page_pos);
 
         /*
@@ -2715,9 +2715,10 @@ struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
         m->middle = NULL;
 
         /* data */
-        m->nr_pages = 0;
+        m->page_count = 0;
         m->page_alignment = 0;
         m->pages = NULL;
+        m->pagelist_count = 0;
         m->pagelist = NULL;
 #ifdef  CONFIG_BLOCK
         m->bio = NULL;
@@ -2890,13 +2891,14 @@ void ceph_msg_last_put(struct kref *kref)
                 ceph_buffer_put(m->middle);
                 m->middle = NULL;
         }
-        m->nr_pages = 0;
+        m->page_count = 0;
         m->pages = NULL;
 
         if (m->pagelist) {
                 ceph_pagelist_release(m->pagelist);
                 kfree(m->pagelist);
                 m->pagelist = NULL;
+                m->pagelist_count = 0;
         }
 
         m->trail = NULL;
@@ -2910,8 +2912,8 @@ EXPORT_SYMBOL(ceph_msg_last_put);
 
 void ceph_msg_dump(struct ceph_msg *msg)
 {
-        pr_debug("msg_dump %p (front_max %d nr_pages %d)\n", msg,
-                 msg->front_max, msg->nr_pages);
+        pr_debug("msg_dump %p (front_max %d page_count %d)\n", msg,
+                 msg->front_max, msg->page_count);
         print_hex_dump(KERN_DEBUG, "header: ",
                        DUMP_PREFIX_OFFSET, 16, 1,
                        &msg->hdr, sizeof(msg->hdr), true);
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 29e4fe09e31a..c3d8c6904df3 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1742,7 +1742,7 @@ int ceph_osdc_start_request(struct ceph_osd_client *osdc,
         int rc = 0;
 
         req->r_request->pages = req->r_pages;
-        req->r_request->nr_pages = req->r_num_pages;
+        req->r_request->page_count = req->r_num_pages;
 #ifdef CONFIG_BLOCK
         req->r_request->bio = req->r_bio;
 #endif
@@ -2093,7 +2093,7 @@ static struct ceph_msg *get_reply(struct ceph_connection *con,
                         goto out;
                 }
                 m->pages = req->r_pages;
-                m->nr_pages = req->r_num_pages;
+                m->page_count = req->r_num_pages;
                 m->page_alignment = req->r_page_alignment;
 #ifdef CONFIG_BLOCK
                 m->bio = req->r_bio;