Re: pg_restore 14 skips ACL COLUMN when --schema is used - Mailing list pgsql-bugs

From Euler Taveira
Subject Re: pg_restore 14 skips ACL COLUMN when --schema is used
Date
Msg-id 90659bbc-e0cb-407d-b42b-5931346735ad@app.fastmail.com
Whole thread Raw
In response to Re: pg_restore 14 skips ACL COLUMN when --schema is used  (Kong Man <kong_mansatiansin@hotmail.com>)
Responses Re: pg_restore 14 skips ACL COLUMN when --schema is used
List pgsql-bugs
On Mon, Jul 31, 2023, at 8:00 PM, Kong Man wrote:
In this example, I generate the public.event table's ToC entries for TABLE, ACL TABLE, and ACL COLUMN, then use the result on --use-list.  pg_restore generates only the CREATE TABLE and GRANTs statements at the table, but not the column, level.

You didn't provide a test case as requested but I investigated this issue
according to your description. The following commands is sufficient to produce
the analysis below.

CREATE ROLE role1;
CREATE ROLE role2;

CREATE TABLE event (
col1 text,
col2 text,
col3 text
);

GRANT SELECT ON TABLE event TO role1;
GRANT SELECT, INSERT, UPDATE, DELETE ON TABLE event TO role2;

GRANT SELECT (col1, col2) ON TABLE event TO role2;
GRANT SELECT, INSERT, UPDATE (col3) ON TABLE event TO role2;

I created these objects and ran pg_restore using a debugger.

pg_dump -Fc -f /tmp/a.dump -d test
pg_restore -l /tmp/a.dump > /tmp/a.toc
gdb --args pg_restore --use-list=/tmp/a.toc -f - /tmp/a.dump

I set a breakpoint to _tocEntryRequired function to inspect the TocEntry values.

(gdb) b _tocEntryRequired

After a few 'continue' and 'p *te' commands I got:

(gdb) c
Continuing.

Breakpoint 1, _tocEntryRequired (te=0x5555555a6910, curSection=SECTION_PRE_DATA, AH=0x5555555a05b0) at pg_backup_archiver.c:2773
2773 }
(gdb) p *te
$8 = {prev = 0x5555555a67a0, next = 0x5555555a6be0, catalogId = {tableoid = 0, oid = 0}, dumpId = 3327, section = SECTION_NONE, hadDumper = false, 
  tag = 0x555555585d30 "COLUMN event.col1", namespace = 0x5555555858b0 "public", tablespace = 0x0, tableam = 0x0, owner = 0x555555585340 "euler", desc = 0x555555585df0 "ACL", 
  defn = 0x5555555a6a00 "GRANT SELECT(col1) ON TABLE public.event TO role2;\n", dropStmt = 0x0, copyStmt = 0x0, dependencies = 0x5555555a6a40, nDeps = 2, dataDumper = 0x0, 
  dataDumperArg = 0x0, formatData = 0x555555585c70, dataLength = 0, reqs = 0, created = false, pending_prev = 0x0, pending_next = 0x0, depCount = 0, revDeps = 0x0, nRevDeps = 0, 
  lockDeps = 0x0, nLockDeps = 0}
(gdb) p te->dependencies[0]
$18 = 214
(gdb) p *AH->tocsByDumpId[214]
$17 = {prev = 0x5555555a64e0, next = 0x5555555a67a0, catalogId = {tableoid = 1259, oid = 183415}, dumpId = 214, section = SECTION_PRE_DATA, hadDumper = false, 
  tag = 0x555555584e00 "event", namespace = 0x555555584f80 "public", tablespace = 0x555555585040 "", tableam = 0x555555584380 "heap", owner = 0x555555584440 "euler", 
  desc = 0x555555584ec0 "TABLE", defn = 0x5555555a6740 "CREATE TABLE public.event (\n    col1 text,\n    col2 text,\n    col3 text\n);\n", 
  dropStmt = 0x5555555a61f0 "DROP TABLE public.event;\n", copyStmt = 0x0, dependencies = 0x0, nDeps = 0, dataDumper = 0x0, dataDumperArg = 0x0, formatData = 0x555555584d40, 
  dataLength = 0, reqs = 1, created = false, pending_prev = 0x0, pending_next = 0x0, depCount = 0, revDeps = 0x0, nRevDeps = 0, lockDeps = 0x0, nLockDeps = 0}
(gdb) p te->dependencies[1]
$21 = 3326
(gdb) p *AH->tocsByDumpId[3326]
$22 = {prev = 0x5555555a6650, next = 0x5555555a6910, catalogId = {tableoid = 0, oid = 0}, dumpId = 3326, section = SECTION_NONE, hadDumper = false, 
  tag = 0x5555555854c0 "TABLE event", namespace = 0x555555585670 "public", tablespace = 0x0, tableam = 0x0, owner = 0x555555585730 "euler", desc = 0x555555585580 "ACL", 
  defn = 0x5555555a6890 "GRANT SELECT ON TABLE public.event TO role1;\nGRANT SELECT,INSERT,DELETE,UPDATE ON TABLE public.event TO role2;\n", dropStmt = 0x0, copyStmt = 0x0, 
  dependencies = 0x5555555a6050, nDeps = 1, dataDumper = 0x0, dataDumperArg = 0x0, formatData = 0x555555585400, dataLength = 0, reqs = 1, created = false, pending_prev = 0x0, 
  pending_next = 0x0, depCount = 0, revDeps = 0x0, nRevDeps = 0, lockDeps = 0x0, nLockDeps = 0}

It means that an ACL for columns has 2 dependencies (nDeps = 2) the function
_tocEntryRequired() returns 0 (see code below).

        else if (ropt->schemaNames.head != NULL ||
                 ropt->schemaExcludeNames.head != NULL ||
                 ropt->selTypes)
        {
            /*
             * In a selective dump/restore, we want to restore these dependent
             * TOC entry types only if their parent object is being restored.
             * Without selectivity options, we let through everything in the
             * archive.  Note there may be such entries with no parent, eg
             * non-default ACLs for built-in objects.
             *
             * This code depends on the parent having been marked already,
             * which should be the case; if it isn't, perhaps due to
             * SortTocFromFile rearrangement, skipping the dependent entry
             * seems prudent anyway.
             *
             * Ideally we'd handle, eg, table CHECK constraints this way too.
             * But it's hard to tell which of their dependencies is the one to
             * consult.
             */
            if (te->nDeps != 1 || 
                TocIDRequired(AH, te->dependencies[0]) == 0)
                return 0;
        }

Hence, ProcessArchiveRestoreOptions() sets te->reqs to 0 that avoids the ACL
for columns to be restored.

te->reqs = _tocEntryRequired(te, curSection, AH);

The discussion [1] in the commit 0d4e6ed3085 does not explain if the 'if' logic
covers all cases. It certainly doesn't for the OP case. The only (hackish)
suggestion I have ATM is to detect ACL for columns and returns 1.




--
Euler Taveira

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