glusterfs: allow setxattr of keys with null values.

Disk based file systems allow to get/set extended attribute key-value pairs where
value can be null. Fuse/libgfapi clients must be able to do the same on a
gluster volume.

Change-Id: Ifc11134cc07f1a3ede43f9d027554dcd10b5c930
BUG: 1135514
Signed-off-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-on: http://review.gluster.org/8567
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

5 files changed, 25 insertions, 13 deletions

diff --git a/libglusterfs/src/dict.c b/libglusterfs/src/dict.c
index cf4a3ce644c..5062f509940 100644
--- a/libglusterfs/src/dict.c
+++ b/libglusterfs/src/dict.c
@@ -2452,13 +2452,10 @@ _dict_serialize (dict_t *this, char *buf)
                 buf += keylen;
                 *buf++ = '\0';
 
-                if (!pair->value->data) {
-                        gf_log ("dict", GF_LOG_ERROR,
-                                "pair->value->data is null!");
-                        goto out;
+                if (pair->value->data) {
+                        memcpy (buf, pair->value->data, vallen);
+                        buf += vallen;
                 }
-                memcpy (buf, pair->value->data, vallen);
-                buf += vallen;
 
                 pair = pair->next;
                 count--;
diff --git a/tests/bugs/bug-1135514-allow-setxattr-with-null-value.t b/tests/bugs/bug-1135514-allow-setxattr-with-null-value.t
new file mode 100644
index 00000000000..cea0566b9bb
--- /dev/null
+++ b/tests/bugs/bug-1135514-allow-setxattr-with-null-value.t
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+. $(dirname $0)/../include.rc
+. $(dirname $0)/../volume.rc
+
+#Test
+cleanup;
+
+TEST glusterd
+TEST pidof glusterd
+TEST $CLI volume create $V0 $H0:$B0/${V0}0
+TEST $CLI volume start $V0
+TEST glusterfs --volfile-id=/$V0 --volfile-server=$H0 $M0 --attribute-timeout=0 --entry-timeout=0
+TEST touch $M0/file
+TEST setfattr -n user.attribute1 $M0/file
+TEST getfattr -n user.attribute1 $M0/file
+cleanup
+
diff --git a/xlators/mount/fuse/src/fuse-bridge.c b/xlators/mount/fuse/src/fuse-bridge.c
index 17335492465..380093a9a7a 100644
--- a/xlators/mount/fuse/src/fuse-bridge.c
+++ b/xlators/mount/fuse/src/fuse-bridge.c
@@ -3192,9 +3192,6 @@ fuse_setxattr (xlator_t *this, fuse_in_header_t *finh, void *msg)
 
         if (fsi->size > 0) {
                 dict_value = memdup (value, fsi->size);
-        } else {
-                gf_log (THIS->name, GF_LOG_ERROR, "value size zero");
-                dict_value = NULL;
         }
         dict_set (state->xattr, newkey,
                   data_from_dynptr ((void *)dict_value, fsi->size));
diff --git a/xlators/storage/posix/src/posix-helpers.c b/xlators/storage/posix/src/posix-helpers.c
index 5f8984cc8a7..8584a68a0e8 100644
--- a/xlators/storage/posix/src/posix-helpers.c
+++ b/xlators/storage/posix/src/posix-helpers.c
@@ -130,7 +130,7 @@ _posix_xattr_get_set_from_backend (posix_xattr_filler_t *filler, char *key)
 
         xattr_size = sys_lgetxattr (filler->real_path, key, NULL, 0);
 
-        if (xattr_size > 0) {
+        if (xattr_size != -1) {
                 value = GF_CALLOC (1, xattr_size + 1,
                                    gf_posix_mt_char);
                 if (!value)
@@ -138,7 +138,7 @@ _posix_xattr_get_set_from_backend (posix_xattr_filler_t *filler, char *key)
 
                 xattr_size = sys_lgetxattr (filler->real_path, key, value,
                                             xattr_size);
-                if (xattr_size <= 0) {
+                if (xattr_size == -1) {
                         gf_log (filler->this->name, GF_LOG_WARNING,
                                 "getxattr failed. path: %s, key: %s",
                                 filler->real_path, key);
diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c
index 090e53f0379..43bd3fc1cfd 100644
--- a/xlators/storage/posix/src/posix.c
+++ b/xlators/storage/posix/src/posix.c
@@ -3703,7 +3703,7 @@ posix_getxattr (call_frame_t *frame, xlator_t *this,
                 }
 #endif
                 size = sys_lgetxattr (real_path, key, NULL, 0);
-                if (size <= 0) {
+                if (size == -1) {
                         op_errno = errno;
                         if ((op_errno == ENOTSUP) || (op_errno == ENOSYS)) {
                                 GF_LOG_OCCASIONALLY (gf_posix_xattr_enotsup_log,
@@ -3928,7 +3928,7 @@ posix_fgetxattr (call_frame_t *frame, xlator_t *this,
                 }
 #endif
                 size = sys_fgetxattr (_fd, key, NULL, 0);
-                if (size <= 0) {
+                if (size == -1) {
                         op_errno = errno;
                         gf_log (this->name,
                                 ((errno == ENODATA || errno == ENOATTR) ?