NFS: Add event tracing for generic NFS events

Add tracepoints for inode attribute updates, attribute revalidation,
writeback start/end fsync start/end, attribute change start/end,
permission check start/end.

The intention is to enable performance tracing using 'perf'as well as
improving debugging.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 13 insertions, 2 deletions

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index f1bdb7254776..d37e8ca9ab86 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -31,6 +31,8 @@
 #include "fscache.h"
 #include "pnfs.h"
 
+#include "nfstrace.h"
+
 #define NFSDBG_FACILITY         NFSDBG_PAGECACHE
 
 #define MIN_POOL_WRITE          (32)
@@ -1732,8 +1734,14 @@ int nfs_wb_all(struct inode *inode)
                 .range_start = 0,
                 .range_end = LLONG_MAX,
         };
+        int ret;
+
+        trace_nfs_writeback_inode_enter(inode);
+
+        ret = sync_inode(inode, &wbc);
 
-        return sync_inode(inode, &wbc);
+        trace_nfs_writeback_inode_exit(inode, ret);
+        return ret;
 }
 EXPORT_SYMBOL_GPL(nfs_wb_all);
 
@@ -1781,6 +1789,8 @@ int nfs_wb_page(struct inode *inode, struct page *page)
         };
         int ret;
 
+        trace_nfs_writeback_page_enter(inode);
+
         for (;;) {
                 wait_on_page_writeback(page);
                 if (clear_page_dirty_for_io(page)) {
@@ -1789,14 +1799,15 @@ int nfs_wb_page(struct inode *inode, struct page *page)
                                 goto out_error;
                         continue;
                 }
+                ret = 0;
                 if (!PagePrivate(page))
                         break;
                 ret = nfs_commit_inode(inode, FLUSH_SYNC);
                 if (ret < 0)
                         goto out_error;
         }
-        return 0;
 out_error:
+        trace_nfs_writeback_page_exit(inode, ret);
         return ret;
 }