glusterd rebalance: minor enhancements

* honor 'stop' command as early as possible
* don't send a setxattr() call if file doesn't have dht linkfile

Change-Id: I159641d03cd15e5818b811ad113d298f7f0112db
BUG: 3584
Reviewed-on: http://review.gluster.com/520
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Shishir Gowda <shishirng@gluster.com>

1 files changed, 43 insertions, 16 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-rebalance.c b/xlators/mgmt/glusterd/src/glusterd-rebalance.c
index ed87a5bb72b..7fe2b8cb21b 100644
--- a/xlators/mgmt/glusterd/src/glusterd-rebalance.c
+++ b/xlators/mgmt/glusterd/src/glusterd-rebalance.c
@@ -56,6 +56,7 @@ gf_glusterd_rebalance_move_data (glusterd_volinfo_t *volinfo, const char *dir)
         struct dirent          *entry                  = NULL;
         struct stat             stbuf                  = {0,};
         char                    full_path[PATH_MAX]    = {0,};
+        char                    linkinfo[PATH_MAX]     = {0,};
         char                    force_string[64]       = {0,};
 
         if (!volinfo->defrag)
@@ -78,6 +79,16 @@ gf_glusterd_rebalance_move_data (glusterd_volinfo_t *volinfo, const char *dir)
                 if (!entry)
                         break;
 
+                /* We have to honor 'stop' (or 'pause'|'commit') as early
+                   as possible */
+                if (volinfo->defrag_status !=
+                    GF_DEFRAG_STATUS_MIGRATE_DATA_STARTED) {
+                        /* It can be one of 'stopped|paused|commit' etc */
+                        closedir (fd);
+                        ret = 1;
+                        goto out;
+                }
+
                 if (!strcmp (entry->d_name, ".") || !strcmp (entry->d_name, ".."))
                         continue;
 
@@ -92,9 +103,20 @@ gf_glusterd_rebalance_move_data (glusterd_volinfo_t *volinfo, const char *dir)
 
                 defrag->num_files_lookedup += 1;
 
+                /* TODO: bring in feature to support hardlink rebalance */
                 if (stbuf.st_nlink > 1)
                         continue;
 
+                /* if distribute is present, it will honor this key.
+                   -1 is returned if distribute is not present or file doesn't
+                   have a link-file. If file has link-file, the path of
+                   link-file will be the value, and also that guarantees
+                   that file has to be mostly migrated */
+                ret = sys_lgetxattr (full_path, GF_XATTR_LINKINFO_KEY,
+                                     &linkinfo, PATH_MAX);
+                if (ret <= 0)
+                        continue;
+
                 ret = sys_lsetxattr (full_path, "distribute.migrate-data",
                                      force_string, strlen (force_string), 0);
                 if (ret < 0)
@@ -106,14 +128,6 @@ gf_glusterd_rebalance_move_data (glusterd_volinfo_t *volinfo, const char *dir)
                         defrag->total_data += stbuf.st_size;
                 }
                 UNLOCK (&defrag->lock);
-
-                if (volinfo->defrag_status !=
-                    GF_DEFRAG_STATUS_MIGRATE_DATA_STARTED) {
-                        /* It can be one of 'stopped|paused|commit' etc */
-                        closedir (fd);
-                        ret = 1;
-                        goto out;
-                }
         }
         closedir (fd);
 
@@ -124,6 +138,16 @@ gf_glusterd_rebalance_move_data (glusterd_volinfo_t *volinfo, const char *dir)
                 if (!entry)
                         break;
 
+                /* We have to honor 'stop' (or 'pause'|'commit') as early
+                   as possible */
+                if (volinfo->defrag_status !=
+                    GF_DEFRAG_STATUS_MIGRATE_DATA_STARTED) {
+                        /* It can be one of 'stopped|paused|commit' etc */
+                        closedir (fd);
+                        ret = 1;
+                        goto out;
+                }
+
                 if (!strcmp (entry->d_name, ".") || !strcmp (entry->d_name, ".."))
                         continue;
 
@@ -169,6 +193,16 @@ gf_glusterd_rebalance_fix_layout (glusterd_volinfo_t *volinfo, const char *dir)
                 if (!entry)
                         break;
 
+                /* We have to honor 'stop' (or 'pause'|'commit') as early
+                   as possible */
+                if (volinfo->defrag_status !=
+                    GF_DEFRAG_STATUS_LAYOUT_FIX_STARTED) {
+                        /* It can be one of 'stopped|paused|commit' etc */
+                        closedir (fd);
+                        ret = 1;
+                        goto out;
+                }
+
                 if (!strcmp (entry->d_name, ".") || !strcmp (entry->d_name, ".."))
                         continue;
 
@@ -180,6 +214,7 @@ gf_glusterd_rebalance_fix_layout (glusterd_volinfo_t *volinfo, const char *dir)
 
                 if (S_ISDIR (stbuf.st_mode)) {
                         /* Fix the layout of the directory */
+                        /* TODO: isn't error code not important ? */
                         sys_lsetxattr (full_path, "trusted.distribute.fix.layout",
                                        "yes", 3, 0);
 
@@ -191,14 +226,6 @@ gf_glusterd_rebalance_fix_layout (glusterd_volinfo_t *volinfo, const char *dir)
                         if (ret)
                                 break;
                 }
-
-                if (volinfo->defrag_status !=
-                    GF_DEFRAG_STATUS_LAYOUT_FIX_STARTED) {
-                        /* It can be one of 'stopped|paused|commit' etc */
-                        closedir (fd);
-                        ret = 1;
-                        goto out;
-                }
         }
         closedir (fd);