fuse-bridge: enable --fopen-keep-cache based on FUSE_AUTO_INVAL_DATA.

If kernel supports FUSE_AUTO_INVAL_DATA then it is safe(r) to turn on
--fopen-keep-cache mode by default. Users report significant improvement
in perf by enabling the mode.

Change-Id: Icf9df4b7b43950d7e25302d9c2a1a7d14571a9a9
BUG: 990744
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/5770
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

3 files changed, 75 insertions, 6 deletions

diff --git a/glusterfsd/src/glusterfsd.c b/glusterfsd/src/glusterfsd.c
index 908345d266d..c6eb58d5156 100644
--- a/glusterfsd/src/glusterfsd.c
+++ b/glusterfsd/src/glusterfsd.c
@@ -163,7 +163,7 @@ static struct argp_option gf_options[] = {
          "Brick name to be registered with Gluster portmapper" },
         {"brick-port", ARGP_BRICK_PORT_KEY, "BRICK-PORT", OPTION_HIDDEN,
          "Brick Port to be registered with Gluster portmapper" },
-	{"fopen-keep-cache", ARGP_FOPEN_KEEP_CACHE_KEY, 0, 0,
+	{"fopen-keep-cache", ARGP_FOPEN_KEEP_CACHE_KEY, "BOOL", OPTION_ARG_OPTIONAL,
 	 "Do not purge the cache on file open"},
 
         {0, 0, 0, 0, "Fuse options:"},
@@ -379,7 +379,8 @@ set_fuse_mount_options (glusterfs_ctx_t *ctx, dict_t *options)
                 }
         }
 
-	if (cmd_args->fopen_keep_cache) {
+	switch (cmd_args->fopen_keep_cache) {
+	case GF_OPTION_ENABLE:
 		ret = dict_set_static_ptr(options, "fopen-keep-cache",
 			"on");
 		if (ret < 0) {
@@ -388,6 +389,23 @@ set_fuse_mount_options (glusterfs_ctx_t *ctx, dict_t *options)
 				"fopen-keep-cache");
 			goto err;
 		}
+		break;
+	case GF_OPTION_DISABLE:
+		ret = dict_set_static_ptr(options, "fopen-keep-cache",
+			"off");
+		if (ret < 0) {
+			gf_log("glusterfsd", GF_LOG_ERROR,
+				"failed to set dict value for key "
+				"fopen-keep-cache");
+			goto err;
+		}
+		break;
+        case GF_OPTION_DEFERRED: /* default */
+        default:
+                gf_log ("glusterfsd", GF_LOG_DEBUG,
+			"fopen-keep-cache mode %d",
+                        cmd_args->fopen_keep_cache);
+                break;
 	}
 
 	if (cmd_args->gid_timeout) {
@@ -990,7 +1008,18 @@ parse_opts (int key, char *arg, struct argp_state *state)
                 break;
 
 	case ARGP_FOPEN_KEEP_CACHE_KEY:
-		cmd_args->fopen_keep_cache = 1;
+                if (!arg)
+                        arg = "on";
+
+                if (gf_string2boolean (arg, &b) == 0) {
+                        cmd_args->fopen_keep_cache = b;
+
+                        break;
+                }
+
+                argp_failure (state, -1, 0,
+                              "unknown cache setting \"%s\"", arg);
+
 		break;
 
 	case ARGP_GID_TIMEOUT_KEY:
@@ -1330,6 +1359,7 @@ glusterfs_ctx_defaults_init (glusterfs_ctx_t *ctx)
 #endif
         cmd_args->fuse_attribute_timeout = -1;
         cmd_args->fuse_entry_timeout = -1;
+	cmd_args->fopen_keep_cache = GF_OPTION_DEFERRED;
 
         INIT_LIST_HEAD (&cmd_args->xlator_options);
         INIT_LIST_HEAD (&cmd_args->volfile_servers);
diff --git a/xlators/mount/fuse/src/fuse-bridge.c b/xlators/mount/fuse/src/fuse-bridge.c
index d864c1fac40..6805056828e 100644
--- a/xlators/mount/fuse/src/fuse-bridge.c
+++ b/xlators/mount/fuse/src/fuse-bridge.c
@@ -3836,6 +3836,40 @@ fuse_init (xlator_t *this, fuse_in_header_t *finh, void *msg)
                         fino.flags |= FUSE_DO_READDIRPLUS;
         }
 
+	if (priv->fopen_keep_cache == 2) {
+		/* If user did not explicitly set --fopen-keep-cache[=off],
+		   then check if kernel support FUSE_AUTO_INVAL_DATA and ...
+		*/
+		if (fini->flags & FUSE_AUTO_INVAL_DATA) {
+			/* ... enable fopen_keep_cache mode if supported.
+			*/
+			gf_log ("glusterfs-fuse", GF_LOG_DEBUG, "Detected "
+				"support for FUSE_AUTO_INVAL_DATA. Enabling "
+				"fopen_keep_cache automatically.");
+			fino.flags |= FUSE_AUTO_INVAL_DATA;
+			priv->fopen_keep_cache = 1;
+		} else {
+			gf_log ("glusterfs-fuse", GF_LOG_DEBUG, "No support "
+				"for FUSE_AUTO_INVAL_DATA. Disabling "
+				"fopen_keep_cache.");
+			/* ... else disable. */
+			priv->fopen_keep_cache = 0;
+		}
+	} else if (priv->fopen_keep_cache == 1) {
+		/* If user explicitly set --fopen-keep-cache[=on],
+		   then enable FUSE_AUTO_INVAL_DATA if possible.
+		*/
+		if (fini->flags & FUSE_AUTO_INVAL_DATA) {
+			gf_log ("glusterfs-fuse", GF_LOG_DEBUG, "fopen_keep_cache "
+				"is explicitly set. Enabling FUSE_AUTO_INVAL_DATA");
+			fino.flags |= FUSE_AUTO_INVAL_DATA;
+		} else {
+			gf_log ("glusterfs-fuse", GF_LOG_WARNING, "fopen_keep_cache "
+				"is explicitly set. Support for "
+				"FUSE_AUTO_INVAL_DATA is missing");
+		}
+	}
+
 	if (fini->flags & FUSE_ASYNC_DIO)
 		fino.flags |= FUSE_ASYNC_DIO;
 
@@ -5080,6 +5114,7 @@ init (xlator_t *this_xl)
         int                fsname_allocated = 0;
         glusterfs_ctx_t   *ctx = NULL;
         gf_boolean_t       sync_to_mount = _gf_false;
+        gf_boolean_t       fopen_keep_cache = _gf_false;
         unsigned long      mntflags = 0;
         char              *mnt_args = NULL;
         eh_t              *event = NULL;
@@ -5225,8 +5260,12 @@ init (xlator_t *this_xl)
                 GF_ASSERT (ret == 0);
         }
 
-        GF_OPTION_INIT("fopen-keep-cache", priv->fopen_keep_cache, bool,
-                cleanup_exit);
+	priv->fopen_keep_cache = 2;
+	if (dict_get (options, "fopen-keep-cache")) {
+		GF_OPTION_INIT("fopen-keep-cache", fopen_keep_cache, bool,
+			       cleanup_exit);
+		priv->fopen_keep_cache = fopen_keep_cache;
+	}
 
         GF_OPTION_INIT("gid-timeout", priv->gid_cache_timeout, int32,
                 cleanup_exit);
diff --git a/xlators/mount/fuse/src/fuse-bridge.h b/xlators/mount/fuse/src/fuse-bridge.h
index 2626638dc4f..93319467ba3 100644
--- a/xlators/mount/fuse/src/fuse-bridge.h
+++ b/xlators/mount/fuse/src/fuse-bridge.h
@@ -101,7 +101,7 @@ struct fuse_private {
         gf_boolean_t         acl;
         gf_boolean_t         selinux;
         gf_boolean_t         read_only;
-	gf_boolean_t	     fopen_keep_cache;
+	int32_t	             fopen_keep_cache;
 	int32_t		     gid_cache_timeout;
         gf_boolean_t         enable_ino32;
         fdtable_t           *fdtable;