mount/fuse: Provide option to use/not use kernel-readdirp

By default fuse kernel readdirp usage in fuse xlator is off.
When mount option use-readdirp=yes is provided it starts using
fuse-kernel's readdirp.

Change-Id: Id37edc53b1adc1638186d956c2f74c1e4e48aa59
BUG: 983477
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/5322
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Raghavendra Bhat <raghavendra@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

7 files changed, 98 insertions, 2 deletions

diff --git a/glusterfsd/src/glusterfsd.c b/glusterfsd/src/glusterfsd.c
index 1c746d9c44a..213b589a5be 100644
--- a/glusterfsd/src/glusterfsd.c
+++ b/glusterfsd/src/glusterfsd.c
@@ -198,6 +198,9 @@ static struct argp_option gf_options[] = {
          "Enable internal memory accounting"},
         {"fuse-mountopts", ARGP_FUSE_MOUNTOPTS_KEY, "OPTIONS", OPTION_HIDDEN,
          "Extra mount options to pass to FUSE"},
+        {"use-readdirp", ARGP_FUSE_USE_READDIRP_KEY, "BOOL", OPTION_ARG_OPTIONAL,
+         "Use readdirp mode in fuse kernel module"
+         " [default: \"off\"]"},
         {0, 0, 0, 0, "Miscellaneous Options:"},
         {0, }
 };
@@ -440,6 +443,16 @@ set_fuse_mount_options (glusterfs_ctx_t *ctx, dict_t *options)
                         goto err;
                 }
         }
+
+        if (cmd_args->use_readdirp) {
+                ret = dict_set_str (options, "use-readdirp",
+                                    cmd_args->use_readdirp);
+                if (ret < 0) {
+                        gf_log ("glusterfsd", GF_LOG_ERROR, "failed to set dict"
+                                " value for key use-readdirp");
+                        goto err;
+                }
+        }
         ret = 0;
 err:
         return ret;
@@ -949,6 +962,25 @@ parse_opts (int key, char *arg, struct argp_state *state)
         case ARGP_FUSE_MOUNTOPTS_KEY:
                 cmd_args->fuse_mountopts = gf_strdup (arg);
                 break;
+
+        case ARGP_FUSE_USE_READDIRP_KEY:
+                if (!arg)
+                        arg = "no";
+
+                if (gf_string2boolean (arg, &b) == 0) {
+                        if (b) {
+                                cmd_args->use_readdirp = "yes";
+                        } else {
+                                cmd_args->use_readdirp = "no";
+                        }
+
+                        break;
+                }
+
+                argp_failure (state, -1, 0,
+                              "unknown use-readdirp setting \"%s\"", arg);
+                break;
+
 	}
 
         return 0;
diff --git a/glusterfsd/src/glusterfsd.h b/glusterfsd/src/glusterfsd.h
index 5b5805d14f4..be91ce54866 100644
--- a/glusterfsd/src/glusterfsd.h
+++ b/glusterfsd/src/glusterfsd.h
@@ -84,6 +84,7 @@ enum argp_option_keys {
 	ARGP_FUSE_CONGESTION_THRESHOLD_KEY = 162,
         ARGP_INODE32_KEY                  = 163,
 	ARGP_FUSE_MOUNTOPTS_KEY		  = 164,
+        ARGP_FUSE_USE_READDIRP_KEY        = 165,
 };
 
 struct _gfd_vol_top_priv_t {
diff --git a/libglusterfs/src/glusterfs.h b/libglusterfs/src/glusterfs.h
index a50cc7fb783..fbf4722cdf1 100644
--- a/libglusterfs/src/glusterfs.h
+++ b/libglusterfs/src/glusterfs.h
@@ -321,6 +321,7 @@ struct _cmd_args {
 
 	/* fuse options */
 	int              fuse_direct_io_mode;
+	char             *use_readdirp;
         int              volfile_check;
 	double           fuse_entry_timeout;
 	double           fuse_negative_timeout;
diff --git a/tests/bugs/bug-983477.t b/tests/bugs/bug-983477.t
new file mode 100755
index 00000000000..dfb0f381d4c
--- /dev/null
+++ b/tests/bugs/bug-983477.t
@@ -0,0 +1,45 @@
+#!/bin/bash
+
+. $(dirname $0)/../include.rc
+. $(dirname $0)/../volume.rc
+
+#This script checks if use-readdirp option works as accepted in mount options
+
+function get_use_readdirp_value {
+        local vol=$1
+        local statedump=$(generate_mount_statedump $vol)
+        local val=$(grep "use_readdirp=" $statedump | cut -f2 -d'=' | tail -1)
+        rm -f $statedump
+        echo $val
+}
+cleanup;
+
+TEST glusterd
+TEST pidof glusterd
+TEST $CLI volume create $V0 $H0:$B0/${V0}
+TEST $CLI volume start $V0
+#If readdirp is enabled statedump should reflect it
+TEST glusterfs --volfile-id=/$V0 --volfile-server=$H0 $M0 --attribute-timeout=0 --entry-timeout=0 --use-readdirp=yes
+TEST cd $M0
+EXPECT_WITHIN 20 "1" get_use_readdirp_value $V0
+TEST cd -
+TEST umount $M0
+
+#If readdirp is enabled statedump should reflect it
+TEST glusterfs --volfile-id=/$V0 --volfile-server=$H0 $M0 --attribute-timeout=0 --entry-timeout=0 --use-readdirp=no
+TEST cd $M0
+EXPECT_WITHIN 20 "0" get_use_readdirp_value $V0
+TEST cd -
+TEST umount $M0
+
+#By default it is disabled.
+TEST glusterfs --volfile-id=/$V0 --volfile-server=$H0 $M0 --attribute-timeout=0 --entry-timeout=0
+TEST cd $M0
+EXPECT_WITHIN 20 "0" get_use_readdirp_value $V0
+TEST cd -
+TEST umount $M0
+
+#Invalid values for use-readdirp should not be accepted
+TEST ! glusterfs --volfile-id=/$V0 --volfile-server=$H0 $M0 --attribute-timeout=0 --entry-timeout=0 --use-readdirp=please-fail
+
+cleanup
diff --git a/xlators/mount/fuse/src/fuse-bridge.c b/xlators/mount/fuse/src/fuse-bridge.c
index 5b6fed9fe76..ce33009d8e3 100644
--- a/xlators/mount/fuse/src/fuse-bridge.c
+++ b/xlators/mount/fuse/src/fuse-bridge.c
@@ -3752,8 +3752,10 @@ fuse_init (xlator_t *this, fuse_in_header_t *finh, void *msg)
         if (fini->minor < 9)
                 *priv->msg0_len_p = sizeof(*finh) + FUSE_COMPAT_WRITE_IN_SIZE;
 #endif
-	if (fini->flags & FUSE_DO_READDIRPLUS)
-		fino.flags |= FUSE_DO_READDIRPLUS;
+        if (priv->use_readdirp) {
+                if (fini->flags & FUSE_DO_READDIRPLUS)
+                        fino.flags |= FUSE_DO_READDIRPLUS;
+        }
 
 	if (fini->flags & FUSE_ASYNC_DIO)
 		fino.flags |= FUSE_ASYNC_DIO;
@@ -4728,6 +4730,7 @@ fuse_priv_dump (xlator_t  *this)
                             (int)private->strict_volfile_check);
         gf_proc_dump_write("reverse_thread_started", "%d",
                            (int)private->reverse_fuse_thread_started);
+        gf_proc_dump_write("use_readdirp", "%d", private->use_readdirp);
 
         return 0;
 }
@@ -5115,6 +5118,8 @@ init (xlator_t *this_xl)
 
         GF_OPTION_INIT ("enable-ino32", priv->enable_ino32, bool, cleanup_exit);
 
+        GF_OPTION_INIT ("use-readdirp", priv->use_readdirp, bool, cleanup_exit);
+
         priv->fuse_dump_fd = -1;
         ret = dict_get_str (options, "dump-fuse", &value_string);
         if (ret == 0) {
@@ -5394,5 +5399,9 @@ struct volume_options options[] = {
         { .key = {"fuse-mountopts"},
           .type = GF_OPTION_TYPE_STR
         },
+        { .key = {"use-readdirp"},
+          .type = GF_OPTION_TYPE_BOOL,
+          .default_value = "no"
+        },
         { .key = {NULL} },
 };
diff --git a/xlators/mount/fuse/src/fuse-bridge.h b/xlators/mount/fuse/src/fuse-bridge.h
index d90b85e727e..2626638dc4f 100644
--- a/xlators/mount/fuse/src/fuse-bridge.h
+++ b/xlators/mount/fuse/src/fuse-bridge.h
@@ -119,6 +119,9 @@ struct fuse_private {
         /* for fuse queue length and congestion threshold */
         int background_qlen;
         int congestion_threshold;
+
+        /* for using fuse-kernel readdirp*/
+        gf_boolean_t use_readdirp;
 };
 typedef struct fuse_private fuse_private_t;
 
diff --git a/xlators/mount/fuse/utils/mount.glusterfs.in b/xlators/mount/fuse/utils/mount.glusterfs.in
index 3fedb8ce342..c0a2ed1a743 100755
--- a/xlators/mount/fuse/utils/mount.glusterfs.in
+++ b/xlators/mount/fuse/utils/mount.glusterfs.in
@@ -135,6 +135,10 @@ start_glusterfs ()
 	cmd_line=$(echo "$cmd_line --direct-io-mode=$direct_io_mode");
     fi
 
+    if [ -n "$use_readdirp" ]; then
+	cmd_line=$(echo "$cmd_line --use-readdirp=$use_readdirp");
+    fi
+
     if [ -n "$volume_name" ]; then
         cmd_line=$(echo "$cmd_line --volume-name=$volume_name");
     fi
@@ -376,6 +380,7 @@ main ()
 			    "congestion-threshold")	cong_threshold=$value ;;
 			    "xlator-option")	xlator_option=$xlator_option" "$pair ;;
 			    "fuse-mountopts")	fuse_mountopts=$value ;;
+                            "use-readdirp") use_readdirp=$value ;;
                             *)
                                 # Passthru
                                 [ -z "$fuse_mountopts" ] || fuse_mountopts="$fuse_mountopts,"