Switch pg_verify_checksums back to a blacklist

This basically reverts commit d55241af705667d4503638e3f77d3689fd6be31,
leaving around a portion of the regression tests still adapted with
empty relation files, and corrupted cases.  This is also proving to be
failing to check properly relation files located in a non-default
tablespace path.

Per discussion with various folks, including Stephen Frost, David
Steele, Andres Freund, Michael Banck and myself.

Reported-by: Michael Banck
Discussion: https://postgr.es/m/20181021134206.GA14282@paquier.xyz
Backpatch-through: 11

diff --git a/src/bin/pg_verify_checksums/pg_verify_checksums.c b/src/bin/pg_verify_checksums/pg_verify_checksums.c
index 36d11ab5638ba4bdf0375c435ae9443e221aef8e..589a3cc58988f2716041efa5519a608196824e4f 100644 (file)
--- a/src/bin/pg_verify_checksums/pg_verify_checksums.c
+++ b/src/bin/pg_verify_checksums/pg_verify_checksums.c
@@ -15,7 +15,6 @@
 
 #include "catalog/pg_control.h"
 #include "common/controldata_utils.h"
-#include "common/relpath.h"
 #include "getopt_long.h"
 #include "pg_getopt.h"
 #include "storage/bufpage.h"
@@ -50,69 +49,27 @@ usage(void)
        printf(_("Report bugs to <pgsql-bugs@postgresql.org>.\n"));
 }
 
-/*
- * isRelFileName
- *
- * Check if the given file name is authorized for checksum verification.
- */
+static const char *const skip[] = {
+       "pg_control",
+       "pg_filenode.map",
+       "pg_internal.init",
+       "PG_VERSION",
+       NULL,
+};
+
 static bool
-isRelFileName(const char *fn)
+skipfile(const char *fn)
 {
-       int                     pos;
-
-       /*----------
-        * Only files including data checksums are authorized for verification.
-        * This is guessed based on the file name by reverse-engineering
-        * GetRelationPath() so make sure to update both code paths if any
-        * updates are done.  The following file name formats are allowed:
-        * <digits>
-        * <digits>.<segment>
-        * <digits>_<forkname>
-        * <digits>_<forkname>.<segment>
-        *
-        * Note that temporary files, beginning with 't', are also skipped.
-        *
-        *----------
-        */
-
-       /* A non-empty string of digits should follow */
-       for (pos = 0; isdigit((unsigned char) fn[pos]); ++pos)
-               ;
-       /* leave if no digits */
-       if (pos == 0)
-               return false;
-       /* good to go if only digits */
-       if (fn[pos] == '\0')
-               return true;
-
-       /* Authorized fork files can be scanned */
-       if (fn[pos] == '_')
-       {
-               int                     forkchar = forkname_chars(&fn[pos + 1], NULL);
-
-               if (forkchar <= 0)
-                       return false;
+       const char *const *f;
 
-               pos += forkchar + 1;
-       }
-
-       /* Check for an optional segment number */
-       if (fn[pos] == '.')
-       {
-               int                     segchar;
-
-               for (segchar = 1; isdigit((unsigned char) fn[pos + segchar]); ++segchar)
-                       ;
-
-               if (segchar <= 1)
-                       return false;
-               pos += segchar;
-       }
+       if (strcmp(fn, ".") == 0 ||
+               strcmp(fn, "..") == 0)
+               return true;
 
-       /* Now this should be the end */
-       if (fn[pos] != '\0')
-               return false;
-       return true;
+       for (f = skip; *f; f++)
+               if (strcmp(*f, fn) == 0)
+                       return true;
+       return false;
 }
 
 static void
@@ -189,7 +146,7 @@ scan_directory(const char *basedir, const char *subdir)
                char            fn[MAXPGPATH];
                struct stat st;
 
-               if (!isRelFileName(de->d_name))
+               if (skipfile(de->d_name))
                        continue;
 
                snprintf(fn, sizeof(fn), "%s/%s", path, de->d_name);