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| author | Thomas Munro <tmunro@postgresql.org> | 2022-02-12 10:21:23 +1300 |
|---|---|---|
| committer | Thomas Munro <tmunro@postgresql.org> | 2022-02-12 10:21:23 +1300 |
| commit | 4eb2176318d0561846c1f9fb3c68bede799d640f (patch) | |
| tree | ae824847ecc96384f9fbcd7010a854cf50ec3e8c /src/backend/commands/tablespace.c | |
| parent | e5691cc9170bcd6c684715c2755d919c5a16fea2 (diff) | |
| download | postgresql-4eb2176318d0561846c1f9fb3c68bede799d640f.tar.gz postgresql-4eb2176318d0561846c1f9fb3c68bede799d640f.zip | |
Fix DROP {DATABASE,TABLESPACE} on Windows.
Previously, it was possible for DROP DATABASE, DROP TABLESPACE and ALTER
DATABASE SET TABLESPACE to fail because other backends still had file
handles open for dropped tables. Windows won't allow a directory
containing unlinked-but-still-open files to be unlinked. Tackle this
problem by forcing all backends to close all smgr fds. No change for
Unix systems, which don't suffer from the problem, but the new code path
can be tested by Unix-based developers by defining
USE_BARRIER_SMGRRELEASE explicitly.
It's possible that PROCSIGNAL_BARRIER_SMGRRELEASE will have more
bug-fixing applications soon (under discussion). Note that this is the
first user of the ProcSignalBarrier mechanism from commit 16a4e4aec. It
could in principle be back-patched as far as 14, but since field
complaints are rare and ProcSignalBarrier hasn't been battle-tested,
that seems like a bad idea. Fix in master only, where these failures
have started to show up in automated testing due to new tests.
Suggested-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/CA+hUKGLdemy2gBm80kz20GTe6hNVwoErE8KwcJk6-U56oStjtg@mail.gmail.com
Diffstat (limited to 'src/backend/commands/tablespace.c')
| -rw-r--r-- | src/backend/commands/tablespace.c | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/src/backend/commands/tablespace.c b/src/backend/commands/tablespace.c index b2ccf5e06ef..40514ab550f 100644 --- a/src/backend/commands/tablespace.c +++ b/src/backend/commands/tablespace.c @@ -536,15 +536,24 @@ DropTableSpace(DropTableSpaceStmt *stmt) * but we can't tell them apart from important data files that we * mustn't delete. So instead, we force a checkpoint which will clean * out any lingering files, and try again. - * - * XXX On Windows, an unlinked file persists in the directory listing + */ + RequestCheckpoint(CHECKPOINT_IMMEDIATE | CHECKPOINT_FORCE | CHECKPOINT_WAIT); + + /* + * On Windows, an unlinked file persists in the directory listing * until no process retains an open handle for the file. The DDL * commands that schedule files for unlink send invalidation messages - * directing other PostgreSQL processes to close the files. DROP - * TABLESPACE should not give up on the tablespace becoming empty - * until all relevant invalidation processing is complete. + * directing other PostgreSQL processes to close the files, but + * nothing guarantees they'll be processed in time. So, we'll also + * use a global barrier to ask all backends to close all files, and + * wait until they're finished. */ - RequestCheckpoint(CHECKPOINT_IMMEDIATE | CHECKPOINT_FORCE | CHECKPOINT_WAIT); +#if defined(USE_BARRIER_SMGRRELEASE) + LWLockRelease(TablespaceCreateLock); + WaitForProcSignalBarrier(EmitProcSignalBarrier(PROCSIGNAL_BARRIER_SMGRRELEASE)); + LWLockAcquire(TablespaceCreateLock, LW_EXCLUSIVE); +#endif + /* And now try again. */ if (!destroy_tablespace_directories(tablespaceoid, false)) { /* Still not empty, the files must be important then */ @@ -1582,6 +1591,11 @@ tblspc_redo(XLogReaderState *record) */ if (!destroy_tablespace_directories(xlrec->ts_id, true)) { +#if defined(USE_BARRIER_SMGRRELEASE) + /* Close all smgr fds in all backends. */ + WaitForProcSignalBarrier(EmitProcSignalBarrier(PROCSIGNAL_BARRIER_SMGRRELEASE)); +#endif + ResolveRecoveryConflictWithTablespace(xlrec->ts_id); /* |