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9df86f997e
Maksim Kupriianov reported very strange crashes in fwrr_update_position() which didn't make sense because of an apparent divide overflow except that the value was not null in the core. It happens that while the locking is correct in all the functions' call graph, the uppermost one (fwrr_get_next_server()) incorrectly expected that its target server was already locked when called. This stupid assumption causd the server lock not to be held when calling the other ones, explaining how it was possible to change the server's eweight by calling srv_lb_commit_status() under the server lock yet collide with its unprotected usage. This commit makes sure that fwrr_get_server_from_group() retrieves a locked server and that fwrr_get_next_server() is responsible for unlocking the server before returning it. There is one subtlety in this function which is that it builds a list of avoided servers that were full while scanning the tree, and all of them are queued in a full state so they must be unlocked upon return. Many thanks to Maksim for providing detailed info allowing to narrow down this bug. This fix must be backported to 1.9. In 1.8 the lock seems much wider and changes to the server's state are performed under the rendez-vous point so this it doesn't seem possible that it happens there.
The HAProxy documentation has been split into a number of different files for ease of use. Please refer to the following files depending on what you're looking for : - INSTALL for instructions on how to build and install HAProxy - LICENSE for the project's license - CONTRIBUTING for the process to follow to submit contributions The more detailed documentation is located into the doc/ directory : - doc/intro.txt for a quick introduction on HAProxy - doc/configuration.txt for the configuration's reference manual - doc/lua.txt for the Lua's reference manual - doc/SPOE.txt for how to use the SPOE engine - doc/network-namespaces.txt for how to use network namespaces under Linux - doc/management.txt for the management guide - doc/regression-testing.txt for how to use the regression testing suite - doc/peers.txt for the peers protocol reference - doc/coding-style.txt for how to adopt HAProxy's coding style - doc/internals for developer-specific documentation (not all up to date)