!2449 创建tablespace增加对symlink的检查

Merge pull request !2449 from 仲夏十三/mas4

src/gausskernel/optimizer/commands/tablespace.cpp

@@ -1293,7 +1293,16 @@ static void create_tablespace_directories(const char* location, const Oid tables
             ereport(ERROR, (errcode_for_file_access(), errmsg("could not remove symbolic link \"%s\": %m", linkloc)));
         }
     }
-
+    /* do not support symbolic link ->  symbolic link */
+    struct stat st;
+    if (lstat(location, &st) == 0) {
+        if (S_ISLNK(st.st_mode)) {
+            ereport(ERROR,
+                (errmodule(MOD_TBLSPC),
+                    errcode(ERRCODE_WRONG_OBJECT_TYPE),
+                    errmsg("location \"%s\" is symbolic link", location)));
+        }
+    }
     /*
      * Create the symlink under PGDATA
      */

src/test/regress/input/tablespace.source

@@ -136,3 +136,8 @@ end;
 
 -- Should succeed
 DROP TABLESPACE testspace;
+
+-- symlink location
+\! mkdir -p @testtablespace@/symlink/sym1
+\! ln -s @testtablespace@/symlink/sym1 @testtablespace@/symlink/sym2
+CREATE TABLESPACE test_symlink LOCATION '@testtablespace@/symlink/sym2';

src/test/regress/output/tablespace_1.source

@@ -267,3 +267,8 @@ ERROR:  DROP TABLESPACE cannot run inside a transaction block
 end;
 -- Should succeed
 DROP TABLESPACE testspace;
+-- symlink location
+\! mkdir -p @testtablespace@/symlink/sym1
+\! ln -s @testtablespace@/symlink/sym1 @testtablespace@/symlink/sym2
+CREATE TABLESPACE test_symlink LOCATION '@testtablespace@/symlink/sym2';
+ERROR:  location "@testtablespace@/symlink/sym2" is symbolic link