rgw_file: all directories are virtual with respect to contents

This change causes directory handles to always report an mtime of
"now."  This is not an invalidate per se--it interacts with the
nfs implementation to produce that result when the implementation
updates its cached attributes.  Hence, it can be modulated by timers
or other rules governing attribute caching at the upper layer.

Fixes: http://tracker.ceph.com/issues/40204
Signed-off-by: Matt Benjamin <mbenjamin@redhat.com>
(cherry picked from commit b4c7d0faeff667c25ab255786999ef0cc844ea2b)

diff --git a/src/rgw/rgw_file.cc b/src/rgw/rgw_file.cc
index 5c0a4d3beffbd40fb8d6defb4d363575695c94f1..4889b28b7b6aa0ee8c6f4635104187c859dda3f4 100644 (file)
--- a/src/rgw/rgw_file.cc
+++ b/src/rgw/rgw_file.cc
@@ -810,7 +810,7 @@ namespace rgw {
     default:
       break;
     };
-
+    /* if rgw_fh is a directory, mtime will be advanced */
     return rgw_fh->stat(st);
   } /* RGWLibFS::getattr */
 

diff --git a/src/rgw/rgw_file.h b/src/rgw/rgw_file.h
index 1bd9433240370b2c518178c1474aeed0cf83f96d..622294b674604fa3ce609ec084d04cf7b2997e22 100644 (file)
--- a/src/rgw/rgw_file.h
+++ b/src/rgw/rgw_file.h
@@ -232,6 +232,15 @@ namespace rgw {
 
     void clear_state();
 
+    void advance_mtime() {
+      /* intended for use on directories, fast-forward mtime so as to
+       * ensure a new, higher value for the change attribute */
+      lock_guard guard(mtx);
+      /* sets ctime as well as mtime, to avoid masking updates should
+       * ctime inexplicably hold a higher value */
+      set_times(real_clock::now());
+    }
+
     boost::variant<file, directory> variant_type;
 
     uint16_t depth;
@@ -342,6 +351,8 @@ namespace rgw {
       switch (fh.fh_type) {
       case RGW_FS_TYPE_DIRECTORY:
        state.unix_mode = RGW_RWXMODE|S_IFDIR;
+       /* virtual directories are always invalid */
+       advance_mtime();
        break;
       case RGW_FS_TYPE_FILE:
        state.unix_mode = RGW_RWMODE|S_IFREG;
@@ -413,8 +424,12 @@ namespace rgw {
 
       if (mask & RGW_SETATTR_ATIME)
        state.atime = st->st_atim;
-      if (mask & RGW_SETATTR_MTIME)
-       state.mtime = st->st_mtim;
+
+      if (mask & RGW_SETATTR_MTIME) {
+       if (fh.fh_type != RGW_FS_TYPE_DIRECTORY)
+         state.mtime = st->st_mtim;
+      }
+
       if (mask & RGW_SETATTR_CTIME)
        state.ctime = st->st_ctim;
     }
@@ -430,18 +445,10 @@ namespace rgw {
 
       st->st_mode = state.unix_mode;
 
-#ifdef HAVE_STAT_ST_MTIMESPEC_TV_NSEC
-      st->st_atimespec = state.atime;
-      st->st_mtimespec = state.mtime;
-      st->st_ctimespec = state.ctime;
-#else
-      st->st_atim = state.atime;
-      st->st_mtim = state.mtime;
-      st->st_ctim = state.ctime;
-#endif
-
       switch (fh.fh_type) {
       case RGW_FS_TYPE_DIRECTORY:
+       /* virtual directories are always invalid */
+       advance_mtime();
        st->st_nlink = state.nlink;
        break;
       case RGW_FS_TYPE_FILE:
@@ -460,6 +467,16 @@ namespace rgw {
        break;
       }
 
+#ifdef HAVE_STAT_ST_MTIMESPEC_TV_NSEC
+      st->st_atimespec = state.atime;
+      st->st_mtimespec = state.mtime;
+      st->st_ctimespec = state.ctime;
+#else
+      st->st_atim = state.atime;
+      st->st_mtim = state.mtime;
+      st->st_ctim = state.ctime;
+#endif
+
       return 0;
     }