85d8b30724
Replace the stopgap fix I made in 0e758ae89 with a cleaner one. The real problem with 4ab5dae94 is that it contorted this function's logic substantially, by introducing a third code path that required different behavior in the function's main loop. That seems quite unnecessary on closer inspection: the new IsBinaryUpgrade case can just share the behavior of the other immediate-unlink cases. Hence, revert 4ab5dae94 and most of 0e758ae89 (keeping the latter's save/restore errno fix), and add IsBinaryUpgrade to the set of conditions tested to choose immediate unlink. Also fix some additional places with sloppy handling of errno, to ensure we have an invariant that we always continue processing after any non-ENOENT failure of do_truncate. I doubt that that's fixing any bug of field importance, so I don't feel it necessary to back-patch; but we might as well get it right while we're here. Also improve the comments, which had drifted a bit from what the code actually does, and neglected to mention some important considerations. Back-patch to v15, not because this is fixing any bug but because it doesn't seem like a good idea for v15's mdunlinkfork logic to be significantly different from both v14 and v16. Discussion: https://postgr.es/m/3797575.1667924888@sss.pgh.pa.us
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download/ See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.