r8695: Patch from James Peach for hires timestamps and efficient

notify code. Bugid #2285. The last commit by me on behalf
of James as he will be able to do his own now :-).
Jeremy.

diff --git a/source/configure.in b/source/configure.in
index d11acd026739cd1c7e6a3dd4ff442c724944601b..e343a9f54fd2e8df7ec9c0e91b8e96e9c2d9ef07 100644 (file)
--- a/source/configure.in
+++ b/source/configure.in
@@ -1196,6 +1196,57 @@ if test x$ac_cv_func_fstat64 = xno ; then
   fi
 fi
 
+#################################################
+# Check whether struct stat has timestamps with sub-second resolution.
+# At least IRIX and Solaris have these.
+#
+# We check that 
+#      all of st_mtim, st_atim and st_ctim exist
+#      all of the members are in fact of type struct timespec
+#
+# There is some conflicting standards weirdness about whether we should use
+# "struct timespec" or "timespec_t". Linux doesn't have timespec_t, so we
+# prefer struct timespec.
+
+AC_CACHE_CHECK([whether struct stat has sub-second timestamps], samba_stat_hires,
+    [
+       AC_TRY_COMPILE(
+           [
+#if TIME_WITH_SYS_TIME
+# include <sys/time.h>
+# include <time.h>
+#else
+# if HAVE_SYS_TIME_H
+#  include <sys/time.h>
+# else
+#  include <time.h>
+# endif
+#endif
+#ifdef HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+           ],
+           [
+               struct timespec t;
+               struct stat s = {0};
+               t.tv_sec = s.st_mtim.tv_sec;
+               t.tv_nsec = s.st_mtim.tv_nsec;
+               t.tv_sec = s.st_ctim.tv_sec;
+               t.tv_nsec = s.st_ctim.tv_nsec;
+               t.tv_sec = s.st_atim.tv_sec;
+               t.tv_nsec = s.st_atim.tv_nsec;
+           ],
+           samba_stat_hires=yes, samba_stat_hires=no)
+    ])
+
+if test x"$samba_stat_hires" = x"yes" ; then
+    AC_DEFINE(HAVE_STAT_ST_MTIM, 1, [whether struct stat contains st_mtim])
+    AC_DEFINE(HAVE_STAT_ST_ATIM, 1, [whether struct stat contains st_atim])
+    AC_DEFINE(HAVE_STAT_ST_CTIM, 1, [whether struct stat contains st_ctim])
+    AC_DEFINE(HAVE_STAT_HIRES_TIMESTAMPS, 1,
+           [whether struct stat has sub-second timestamps])
+fi
+
 #####################################
 # we might need the resolv library on some systems
 AC_CHECK_LIB(resolv, dn_expand)

diff --git a/source/smbd/notify_hash.c b/source/smbd/notify_hash.c
index 08eefab65205aadd0109068816a9809cb0247c1d..ee7d4314eef66d9a83ddca96fb745355f9342653 100644 (file)
--- a/source/smbd/notify_hash.c
+++ b/source/smbd/notify_hash.c
@@ -23,14 +23,28 @@
 
 struct change_data {
        time_t last_check_time; /* time we last checked this entry */
+#ifdef HAVE_STAT_HIRES_TIMESTAMPS
+       struct timespec modify_time;
+       struct timespec status_time;
+#else
        time_t modify_time; /* Info from the directory we're monitoring. */ 
        time_t status_time; /* Info from the directory we're monitoring. */
+#endif
        time_t total_time; /* Total time of all directory entries - don't care if it wraps. */
        unsigned int num_entries; /* Zero or the number of files in the directory. */
        unsigned int mode_sum;
        unsigned char name_hash[16];
 };
 
+
+#ifdef HAVE_STAT_HIRES_TIMESTAMPS
+/* Compare struct timespec. */
+#define TIMESTAMP_NEQ(x, y) (((x).tv_sec != (y).tv_sec) || ((x).tv_nsec != (y).tv_nsec))
+#else
+/* Compare time_t . */
+#define TIMESTAMP_NEQ(x, y) ((x) != (y))
+#endif
+
 /****************************************************************************
  Create the hash we will use to determine if the contents changed.
 *****************************************************************************/
@@ -52,20 +66,36 @@ static BOOL notify_hash(connection_struct *conn, char *path, uint32 flags,
        if(SMB_VFS_STAT(conn,path, &st) == -1)
                return False;
 
+#ifdef HAVE_STAT_HIRES_TIMESTAMPS
+       data->modify_time = st.st_mtim;
+       data->status_time = st.st_ctim;
+#else
        data->modify_time = st.st_mtime;
        data->status_time = st.st_ctime;
+#endif
 
        if (old_data) {
                /*
                 * Shortcut to avoid directory scan if the time
                 * has changed - we always must return true then.
                 */
-               if (old_data->modify_time != data->modify_time ||
-                       old_data->status_time != data->status_time ) {
+               if (TIMESTAMP_NEQ(old_data->modify_time, data->modify_time) ||
+                   TIMESTAMP_NEQ(old_data->status_time, data->status_time) ) {
                                return True;
                }
        }
  
+        if (S_ISDIR(st.st_mode) && 
+            (flags & ~(FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME)) == 0)
+        {
+               /* This is the case of a client wanting to know only when
+                * the contents of a directory changes. Since any file
+                * creation, rename or deletion will update the directory
+                * timestamps, we don't need to create a hash.
+                */
+                return True;
+        }
+
        /*
         * If we are to watch for changes that are only stored
         * in inodes of files, not in the directory inode, we must
@@ -176,8 +206,8 @@ static BOOL hash_check_notify(connection_struct *conn, uint16 vuid, char *path,
        }
 
        if (!notify_hash(conn, path, flags, &data2, data) ||
-           data2.modify_time != data->modify_time ||
-           data2.status_time != data->status_time ||
+           TIMESTAMP_NEQ(data2.modify_time, data->modify_time) ||
+           TIMESTAMP_NEQ(data2.status_time, data->status_time) ||
            data2.total_time != data->total_time ||
            data2.num_entries != data->num_entries ||
                data2.mode_sum != data->mode_sum ||