fuse: change behavior of direct io mode.

by default disable direct-io only for fds opened with O_RDONLY.
(previously direct io mode was disabled in any case).

Added new command line option to force enabling of direct io mode

Signed-off-by: Raghavendra G <raghavendra@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 801 (Direct io-mode support and related changes in caching translators.)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=801

3 files changed, 34 insertions, 18 deletions

diff --git a/glusterfsd/src/glusterfsd.c b/glusterfsd/src/glusterfsd.c
index d2c156321..60dbe6192 100644
--- a/glusterfsd/src/glusterfsd.c
+++ b/glusterfsd/src/glusterfsd.c
@@ -135,6 +135,8 @@ static struct argp_option gf_options[] = {
  	{0, 0, 0, 0, "Fuse options:"},
  	{"disable-direct-io-mode", ARGP_DISABLE_DIRECT_IO_MODE_KEY, 0, 0, 
  	 "Disable direct I/O mode in fuse kernel module"},
+        {"enable-direct-io-mode", ARGP_ENABLE_DIRECT_IO_MODE_KEY, 0, 0,
+         "Force direct I/O mode in fuse kernel module"},
  	{"entry-timeout", ARGP_ENTRY_TIMEOUT_KEY, "SECONDS", 0, 
  	 "Set entry timeout to SECONDS in fuse kernel module [default: 1]"},
  	{"attribute-timeout", ARGP_ATTRIBUTE_TIMEOUT_KEY, "SECONDS", 0, 
@@ -321,7 +323,7 @@ _add_fuse_mount (xlator_t *graph)
 	/* On Darwin machines, O_APPEND is not handled, 
 	 * which may corrupt the data 
 	 */
-	if (cmd_args->fuse_direct_io_mode_flag == _gf_true) {
+	if (cmd_args->fuse_direct_io_mode_flag == 1) {
 		gf_log ("glusterfs", GF_LOG_DEBUG, 
 			 "'direct-io-mode' in fuse causes data corruption "
 			"if O_APPEND is used. disabling 'direct-io-mode'");
@@ -333,14 +335,19 @@ _add_fuse_mount (xlator_t *graph)
 				       cmd_args->non_local);
 	
 #else /* ! DARWIN HOST OS */
-	if (cmd_args->fuse_direct_io_mode_flag == _gf_true) {
-		ret = dict_set_static_ptr (top->options, ZR_DIRECT_IO_OPT,
-					   "enable");
-	} else  {
-		ret = dict_set_static_ptr (top->options, ZR_DIRECT_IO_OPT,
-					   "disable");
-	}
-
+        switch (cmd_args->fuse_direct_io_mode_flag) {
+        case 0: /* disable */
+                 ret = dict_set_static_ptr (top->options, ZR_DIRECT_IO_OPT,
+                                            "disable");
+                break;
+        case 1: /* enable */
+                ret = dict_set_static_ptr (top->options, ZR_DIRECT_IO_OPT,
+                                           "enable");
+                break;
+        case 2: /* default */
+        default:
+                break;
+        }
 #endif /* GF_DARWIN_HOST_OS */
 	
 	graph->parents = CALLOC (1, sizeof (xlator_list_t));
@@ -825,9 +832,13 @@ parse_opts (int key, char *arg, struct argp_state *state)
 		break;
 		
 	case ARGP_DISABLE_DIRECT_IO_MODE_KEY:
-		cmd_args->fuse_direct_io_mode_flag = _gf_false;
-		break;
-		
+                cmd_args->fuse_direct_io_mode_flag = 0;
+                break;
+
+        case ARGP_ENABLE_DIRECT_IO_MODE_KEY:
+                cmd_args->fuse_direct_io_mode_flag = 1;
+                break;
+
 	case ARGP_ENTRY_TIMEOUT_KEY:
 		d = 0.0;
 		
@@ -1064,7 +1075,7 @@ main (int argc, char *argv[])
 
 	/* parsing command line arguments */
 	cmd_args->log_level = DEFAULT_LOG_LEVEL;
-	cmd_args->fuse_direct_io_mode_flag = _gf_true;
+	cmd_args->fuse_direct_io_mode_flag = 2;
 	
 	INIT_LIST_HEAD (&cmd_args->xlator_options);
 
diff --git a/glusterfsd/src/glusterfsd.h b/glusterfsd/src/glusterfsd.h
index 262783070..56b6d4ca1 100644
--- a/glusterfsd/src/glusterfsd.h
+++ b/glusterfsd/src/glusterfsd.h
@@ -62,12 +62,13 @@ enum argp_option_keys {
 	ARGP_RUN_ID_KEY = 'r', 
 	ARGP_DEBUG_KEY = 133, 
 	ARGP_DISABLE_DIRECT_IO_MODE_KEY = 134, 
+	ARGP_ENABLE_DIRECT_IO_MODE_KEY = 139, 
 	ARGP_ENTRY_TIMEOUT_KEY = 135, 
 	ARGP_ATTRIBUTE_TIMEOUT_KEY = 136, 
 	ARGP_VOLUME_NAME_KEY = 137,
 	ARGP_XLATOR_OPTION_KEY = 138,
 #ifdef GF_DARWIN_HOST_OS
-	ARGP_NON_LOCAL_KEY = 139,
+	ARGP_NON_LOCAL_KEY = 140,
 #endif /* DARWIN */
 	ARGP_VOLFILE_ID_KEY = 143, 
         ARGP_VOLFILE_CHECK_KEY = 144,
diff --git a/xlators/mount/fuse/src/fuse-bridge.c b/xlators/mount/fuse/src/fuse-bridge.c
index 1dc710c96..8f6dabd0a 100644
--- a/xlators/mount/fuse/src/fuse-bridge.c
+++ b/xlators/mount/fuse/src/fuse-bridge.c
@@ -621,7 +621,9 @@ fuse_fd_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                 fi.flags = state->flags;
 
                 if (!S_ISDIR (fd->inode->st_mode)) {
-                        if ((fi.flags & 3) && priv->direct_io_mode)
+                        if (((priv->direct_io_mode == 2)
+                             && ((state->flags & O_ACCMODE) != O_RDONLY))
+                            || (priv->direct_io_mode == 1))
                                 fi.direct_io = 1;
                 }
 
@@ -1327,7 +1329,9 @@ fuse_create_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
         if (op_ret >= 0) {
                 fi.fh = (unsigned long) fd;
 
-                if ((fi.flags & 3) && priv->direct_io_mode)
+                if (((priv->direct_io_mode == 2)
+                     && ((state->flags & O_ACCMODE) != O_RDONLY))
+                    || (priv->direct_io_mode == 1))
                         fi.direct_io = 1;
 
                 gf_log ("glusterfs-fuse", GF_LOG_TRACE,
@@ -2372,7 +2376,7 @@ fuse_setlk (fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi,
 static void
 fuse_init (void *data, struct fuse_conn_info *conn)
 {
-        return;
+
 }
 
 static void
@@ -2793,7 +2797,7 @@ init (xlator_t *this_xl)
                 priv->entry_timeout = 1.0; /* default */
 
 
-        priv->direct_io_mode = 1;
+        priv->direct_io_mode = 2;
         ret = dict_get_str (options, ZR_DIRECT_IO_OPT, &value_string);
         if (value_string) {
                 ret = gf_string2boolean (value_string, &priv->direct_io_mode);