From 26b03ef7622f20936864f33fa6410df9b87b5047 Mon Sep 17 00:00:00 2001
From: laishenghao <laishenghao1@huawei.com>
Date: Sat, 3 Jun 2023 17:51:39 +0800
Subject: [PATCH] =?UTF-8?q?=E8=A7=A3=E5=86=B3=E5=88=9B=E5=BB=BA=E8=A1=A8?=
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---
 .../optimizer/commands/tablespace.cpp         | 54 +++++++++++++++++++
 src/test/regress/input/tablespace.source      |  9 +++-
 src/test/regress/output/tablespace_1.source   |  7 +++
 3 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/src/gausskernel/optimizer/commands/tablespace.cpp b/src/gausskernel/optimizer/commands/tablespace.cpp
index cf13efc250..3ca2a56e6d 100644
--- a/src/gausskernel/optimizer/commands/tablespace.cpp
+++ b/src/gausskernel/optimizer/commands/tablespace.cpp
@@ -100,6 +100,8 @@ static void createtbspc_abort_callback(bool isCommit, const void* arg);
 
 Datum CanonicalizeTablespaceOptions(Datum datum);
 
+#define CHECK_PATH_RETRY_COUNT 100
+
 #define CANONICALIZE_PATH(path)         \
     do {                                \
         if (NULL != (path)) {           \
@@ -2478,12 +2480,56 @@ char* get_tablespace_name(Oid spc_oid)
     return result;
 }
 
+bool IsPathContainsSymlink(char* path)
+{
+    struct stat statbuf;
+    errno_t rc;
+    char* ptr = path;
+
+    if (*ptr == '/') {
+        ++ptr;
+    }
+
+    for (bool isLast = false; !isLast; ++ptr) {
+        if (*ptr == '\0') {
+            isLast = true;
+        } else if (*ptr != '/') {
+            continue;
+        }
+
+        if (!isLast && ptr[1] == '\0') {
+            isLast = true;
+        }
+
+        *ptr = '\0';
+        rc = memset_s(&statbuf, sizeof(statbuf), 0, sizeof(statbuf));
+        if (rc != EOK) {
+            continue;
+        }
+
+        if (lstat(path, &statbuf) == 0 && S_ISLNK(statbuf.st_mode)) {
+            return true;
+        }
+
+        if (!isLast) {
+            *ptr = '/';
+        }
+    }
+    
+    return false;
+}
+
 /* check if the dir(location) is exist, if not create it */
 void check_create_dir(char* location)
 {
     int ret;
+    int retryCount = 0;
+    bool hasLink = IsPathContainsSymlink(location);
 
 recheck:
+    if (hasLink) {
+        ++retryCount;
+    }
     /* We believe that the location we got from the record is credible. */
     switch (ret = pg_check_dir(location)) {
         case 0: {
@@ -2492,6 +2538,14 @@ recheck:
             if (pg_mkdir_p_used_by_gaussdb(tmplocation, S_IRWXU) == -1) {
                 if (errno == EEXIST) {
                     pfree_ext(tmplocation);
+
+                    if (hasLink && retryCount > CHECK_PATH_RETRY_COUNT) {
+                        ereport(ERROR, (errmodule(MOD_TBLSPC),
+                            errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+                            errmsg("recheck location \"%s\" exeed max times.", location),
+                            errdetail("the location contains symbolic link, the linked path likely has been deleted.")));
+                    }
+
                     goto recheck;
                 } else
                     ereport(ERROR,
diff --git a/src/test/regress/input/tablespace.source b/src/test/regress/input/tablespace.source
index 3381662346..0548e8e499 100644
--- a/src/test/regress/input/tablespace.source
+++ b/src/test/regress/input/tablespace.source
@@ -140,4 +140,11 @@ 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';
\ No newline at end of file
+CREATE TABLESPACE test_symlink LOCATION '@testtablespace@/symlink/sym2';
+
+-- check linked path deleted
+\! mkdir -p @testtablespace@/symlink/will_delete
+\! ln -s @testtablespace@/symlink/will_delete @testtablespace@/symlink/will_delete_link
+\! rm -rf @testtablespace@/symlink/will_delete
+
+CREATE TABLESPACE deleted_symlink LOCATION '@testtablespace@/symlink/will_delete_link/local';
diff --git a/src/test/regress/output/tablespace_1.source b/src/test/regress/output/tablespace_1.source
index 1d507edb80..5c5e542fd5 100644
--- a/src/test/regress/output/tablespace_1.source
+++ b/src/test/regress/output/tablespace_1.source
@@ -272,3 +272,10 @@ DROP TABLESPACE testspace;
 \! ln -s @testtablespace@/symlink/sym1 @testtablespace@/symlink/sym2
 CREATE TABLESPACE test_symlink LOCATION '@testtablespace@/symlink/sym2';
 ERROR:  location "@testtablespace@/symlink/sym2" is symbolic link
+-- check linked path deleted
+\! mkdir -p @testtablespace@/symlink/will_delete
+\! ln -s @testtablespace@/symlink/will_delete @testtablespace@/symlink/will_delete_link
+\! rm -rf @testtablespace@/symlink/will_delete
+CREATE TABLESPACE deleted_symlink LOCATION '@testtablespace@/symlink/will_delete_link/local';
+ERROR:  recheck location "@testtablespace@/symlink/will_delete_link" exeed max times.
+DETAIL:  the location contains symbolic link, the linked path likely has been deleted.
-- 
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