afs: Trace the sending of pages

Add a pair of tracepoints to log the sending of pages for an FS.StoreData
or FS.StoreData64 operation.

Tracepoint afs_send_pages notes each set of pages added to the operation.
There may be several of these per operation as we get up at most 8
contiguous pages in one go because the bvec we're using is on the stack.

Tracepoint afs_sent_pages notes the end of adding data from a whole run of
pages to the operation and the completion of the request phase.

Signed-off-by: David Howells <dhowells@redhat.com>

2 files changed, 64 insertions, 0 deletions

diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 59cc58022c4d..06a51d70b82b 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -303,6 +303,8 @@ static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
 
         do {
                 afs_load_bvec(call, msg, bv, first, last, offset);
+                trace_afs_send_pages(call, msg, first, last, offset);
+
                 offset = 0;
                 bytes = msg->msg_iter.count;
                 nr = msg->msg_iter.nr_segs;
@@ -317,6 +319,7 @@ static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
                 first += nr;
         } while (first <= last);
 
+        trace_afs_sent_pages(call, call->first, last, first, ret);
         return ret;
 }
 
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
index dd9d2600ee98..c780f4c39a53 100644
--- a/include/trace/events/afs.h
+++ b/include/trace/events/afs.h
@@ -320,6 +320,67 @@ TRACE_EVENT(afs_call_done,
                       __entry->rx_call)
             );
 
+TRACE_EVENT(afs_send_pages,
+            TP_PROTO(struct afs_call *call, struct msghdr *msg,
+                     pgoff_t first, pgoff_t last, unsigned int offset),
+
+            TP_ARGS(call, msg, first, last, offset),
+
+            TP_STRUCT__entry(
+                    __field(struct afs_call *,          call            )
+                    __field(pgoff_t,                    first           )
+                    __field(pgoff_t,                    last            )
+                    __field(unsigned int,               nr              )
+                    __field(unsigned int,               bytes           )
+                    __field(unsigned int,               offset          )
+                    __field(unsigned int,               flags           )
+                             ),
+
+            TP_fast_assign(
+                    __entry->call = call;
+                    __entry->first = first;
+                    __entry->last = last;
+                    __entry->nr = msg->msg_iter.nr_segs;
+                    __entry->bytes = msg->msg_iter.count;
+                    __entry->offset = offset;
+                    __entry->flags = msg->msg_flags;
+                           ),
+
+            TP_printk(" c=%p %lx-%lx-%lx b=%x o=%x f=%x",
+                      __entry->call,
+                      __entry->first, __entry->first + __entry->nr - 1, __entry->last,
+                      __entry->bytes, __entry->offset,
+                      __entry->flags)
+            );
+
+TRACE_EVENT(afs_sent_pages,
+            TP_PROTO(struct afs_call *call, pgoff_t first, pgoff_t last,
+                     pgoff_t cursor, int ret),
+
+            TP_ARGS(call, first, last, cursor, ret),
+
+            TP_STRUCT__entry(
+                    __field(struct afs_call *,          call            )
+                    __field(pgoff_t,                    first           )
+                    __field(pgoff_t,                    last            )
+                    __field(pgoff_t,                    cursor          )
+                    __field(int,                        ret             )
+                             ),
+
+            TP_fast_assign(
+                    __entry->call = call;
+                    __entry->first = first;
+                    __entry->last = last;
+                    __entry->cursor = cursor;
+                    __entry->ret = ret;
+                           ),
+
+            TP_printk(" c=%p %lx-%lx c=%lx r=%d",
+                      __entry->call,
+                      __entry->first, __entry->last,
+                      __entry->cursor, __entry->ret)
+            );
+
 #endif /* _TRACE_AFS_H */
 
 /* This part must be outside protection */