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>

diff --git a/src/rgw/rgw_file.cc b/src/rgw/rgw_file.cc
index 74982308a64bad2177e00e6272063c13157871f6..77758f82a34e29c8bbd6bc31e083af5275ce2a16 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 e2395be3a56ec3811b35f335b44f927afc180eb4..33872d88a6d246fd02f48c5e774ff99876fb7b48 100644 (file)
--- a/src/rgw/rgw_file.h
+++ b/src/rgw/rgw_file.h
@@ -239,6 +239,15 @@ 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;
@@ -349,6 +358,8 @@ 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;
@@ -420,8 +431,12 @@ 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;
     }
@@ -437,18 +452,10 @@ 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:
@@ -467,6 +474,16 @@ 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;
     }