Introduce new extended attribute: node-uuid

Request for trusted.glusterfs.node-uuid returns pathinfo
like string but containing the UUID of glusterd instead
of the backend path for the requested file. This info
is benificial for tasks like parallel rebalance that will
make use of the UUID for data locality.

Change-Id: I766a09cc4a5f63aebd11c73107924a1b29242dcf
BUG: 772610
Signed-off-by: Venky Shankar <vshankar@redhat.com>
Reviewed-on: http://review.gluster.com/2614
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Shishir Gowda <shishirng@gluster.com>
Reviewed-by: Vijay Bellur <vijay@gluster.com>

2 files changed, 90 insertions, 34 deletions

diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c
index deaf2e77..1b4d1a33 100644
--- a/xlators/storage/posix/src/posix.c
+++ b/xlators/storage/posix/src/posix.c
@@ -2379,21 +2379,23 @@ int32_t
 posix_getxattr (call_frame_t *frame, xlator_t *this,
                 loc_t *loc, const char *name)
 {
-        struct posix_private *priv  = NULL;
-        int32_t  op_ret         = -1;
-        int32_t  op_errno       = 0;
-        int32_t  list_offset    = 0;
-        size_t   size           = 0;
-        size_t   remaining_size = 0;
-        char     key[4096]      = {0,};
-        char     host_buf[1024] = {0,};
-        char *   value          = NULL;
-        char *   list           = NULL;
-        char *   real_path      = NULL;
-        dict_t * dict           = NULL;
-        char *   file_contents  = NULL;
-        int      ret            = -1;
-        char *   path           = NULL;
+        struct posix_private *priv           = NULL;
+        int32_t               op_ret         = -1;
+        int32_t               op_errno       = 0;
+        int32_t               list_offset    = 0;
+        size_t                size           = 0;
+        size_t                remaining_size = 0;
+        char     key[4096]                   = {0,};
+        char     host_buf[1024]              = {0,};
+        char                 *value          = NULL;
+        char                 *list           = NULL;
+        char                 *real_path      = NULL;
+        dict_t               *dict           = NULL;
+        char                 *file_contents  = NULL;
+        int                   ret            = -1;
+        char                 *path           = NULL;
+        char                 *rpath          = NULL;
+        char                 *dyn_rpath      = NULL;
 
         DECLARE_OLD_FS_ID_VAR;
 
@@ -2444,15 +2446,50 @@ posix_getxattr (call_frame_t *frame, xlator_t *this,
         }
         if (loc->inode && name &&
             (strcmp (name, GF_XATTR_PATHINFO_KEY) == 0)) {
-                snprintf (host_buf, 1024, "<POSIX:%s:%s>", priv->hostname,
-                          real_path);
-                size = strlen (host_buf) + 1;
-                ret = dict_set_str (dict, GF_XATTR_PATHINFO_KEY,
-                                    host_buf);
+                if (LOC_HAS_ABSPATH (loc))
+                        MAKE_REAL_PATH (rpath, this, loc->path);
+                else
+                        rpath = real_path;
+
+                (void) snprintf (host_buf, 1024, "<POSIX(%s):%s:%s>",
+                                 priv->base_path, priv->hostname, rpath);
+
+                dyn_rpath = gf_strdup (host_buf);
+                if (!dyn_rpath) {
+                        ret = -1;
+                        goto done;
+                }
+                size = strlen (dyn_rpath) + 1;
+                ret = dict_set_dynstr (dict, GF_XATTR_PATHINFO_KEY,
+                                       dyn_rpath);
                 if (ret < 0) {
                         gf_log (this->name, GF_LOG_WARNING,
                                 "could not set value (%s) in dictionary",
-                                host_buf);
+                                dyn_rpath);
+                }
+
+                goto done;
+        }
+
+        if (loc->inode && name &&
+            (strcmp (name, GF_XATTR_NODE_UUID_KEY) == 0)
+            && !uuid_is_null (priv->glusterd_uuid)) {
+                (void) snprintf (host_buf, 1024, "<%s>",
+                                 uuid_utoa (priv->glusterd_uuid));
+
+                dyn_rpath = gf_strdup (host_buf);
+                if (!dyn_rpath) {
+                        ret = -1;
+                        goto done;
+                }
+
+                size = strlen (dyn_rpath) + 1;
+                ret = dict_set_dynstr (dict, GF_XATTR_NODE_UUID_KEY,
+                                       dyn_rpath);
+                if (ret < 0) {
+                        gf_log (this->name, GF_LOG_WARNING,
+                                "could not set value (%s) in dictionary",
+                                dyn_rpath);
                 }
                 goto done;
         }
@@ -3762,19 +3799,20 @@ mem_acct_init (xlator_t *this)
 int
 init (xlator_t *this)
 {
-        struct posix_private  *_private      = NULL;
-        data_t                *dir_data      = NULL;
-        data_t                *tmp_data      = NULL;
-        struct stat            buf           = {0,};
-        gf_boolean_t           tmp_bool      = 0;
-        int                    dict_ret      = 0;
-        int                    ret           = 0;
-        int                    op_ret        = -1;
-        int32_t                janitor_sleep = 0;
-        uuid_t                 old_uuid      = {0,};
-        uuid_t                 dict_uuid     = {0,};
-        uuid_t                 gfid          = {0,};
-        uuid_t                 rootgfid = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
+        struct posix_private *_private      = NULL;
+        data_t               *dir_data      = NULL;
+        data_t               *tmp_data      = NULL;
+        struct stat           buf           = {0,};
+        gf_boolean_t          tmp_bool      = 0;
+        int                   dict_ret      = 0;
+        int                   ret           = 0;
+        int                   op_ret        = -1;
+        int32_t               janitor_sleep = 0;
+        uuid_t                old_uuid      = {0,};
+        uuid_t                dict_uuid     = {0,};
+        uuid_t                gfid          = {0,};
+        uuid_t                rootgfid      = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
+        char                 *guuid         = NULL;
 
         dir_data = dict_get (this->options, "directory");
 
@@ -4022,6 +4060,19 @@ init (xlator_t *this)
                                 "for every open)");
         }
 
+        ret = dict_get_str (this->options, "glusterd-uuid", &guuid);
+        if (!ret) {
+                if (uuid_parse (guuid, _private->glusterd_uuid))
+                        gf_log (this->name, GF_LOG_WARNING, "Cannot parse "
+                                "glusterd (node) UUID, node-uuid xattr "
+                                "request would return - \"No such attribute\"");
+        } else {
+                gf_log (this->name, GF_LOG_DEBUG, "No glusterd (node) UUID "
+                        "passed - node-uuid xattr request will return "
+                        "\"No such attribute\"");
+        }
+        ret = 0;
+
         _private->janitor_sleep_duration = 600;
 
         dict_ret = dict_get_int32 (this->options, "janitor-sleep-duration",
@@ -4175,5 +4226,7 @@ struct volume_options options[] = {
           .type = GF_OPTION_TYPE_INT },
         { .key  = {"volume-id"},
           .type = GF_OPTION_TYPE_ANY },
+        { .key  = {"glusterd-uuid"},
+          .type = GF_OPTION_TYPE_STR },
         { .key  = {NULL} }
 };
diff --git a/xlators/storage/posix/src/posix.h b/xlators/storage/posix/src/posix.h
index c72adac9..c551ffc1 100644
--- a/xlators/storage/posix/src/posix.h
+++ b/xlators/storage/posix/src/posix.h
@@ -122,6 +122,9 @@ struct posix_private {
 
         struct stat     handledir;
 
+/* uuid of glusterd that swapned the brick process */
+        uuid_t glusterd_uuid;
+
 };
 
 #define POSIX_BASE_PATH(this) (((struct posix_private *)this->private)->base_path)