mirror of
https://github.com/postgres/postgres.git
synced 2025-05-01 01:04:50 +03:00
ee5d1de04f
In _bt_unlink_halfdead_page(), we might fail to find an immediate left sibling of the target page, perhaps because of corruption of the page sibling links. The code intends to cope with this by just abandoning the deletion attempt; but what actually happens is that it fails outright due to releasing the same buffer lock twice. (And error recovery masks a second problem, which is possible leakage of a pin on another page.) Seems to have been introduced by careless refactoring in commit efada2b8e. Since there are multiple cases to consider, let's make releasing the buffer lock in the failure case the responsibility of _bt_unlink_halfdead_page() not its caller. Also, avoid fetching the leaf page's left-link again after we've dropped lock on the page. This is probably harmless, but it's not exactly good coding practice. Per report from Kyotaro Horiguchi. Back-patch to 9.4 where the faulty code was introduced. Discussion: <20160803.173116.111915228.horiguchi.kyotaro@lab.ntt.co.jp>
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: http://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 http://www.postgresql.org/download/. For more information look at our web site located at http://www.postgresql.org/.