| commit | b6b260f2b42aa5a135e4b57ce102dcb0dbbf88c3 | |
| author | Matthew Dillon <dillon@apollo.backplane.com> | |
| Fri, 10 Jun 2016 18:25:58 +0000 (10 11:25 -0700) | ||
| committer | Matthew Dillon <dillon@apollo.backplane.com> | |
| Sat, 11 Jun 2016 02:50:58 +0000 (10 19:50 -0700) | ||
| tree | ef0708febc8c76f103d7c41d83e865f986db2db3 | treesnapshot (tar.gz zip) |
| parent | f073608f1ef4bf6ab9cc04e0b4fac433b6cd2242 | commitdiff |
hammer2 - Fix upgrade deadlock
* Fix a deadlock which occurs when hammer2_chain_unlock() tries to
upgrade the 'last' shared lock to exclusive. This can deadlock if
another thread obtains the chain shared before we manage to do the
upgrade.
Just use a 'try' here. If it fails it means someone else got a lock
(of any kind) and we don't have to worry about dropping the chain data.
* Replace hammer2_mtx_upgrade() with hammer2_mtx_upgrade_try(). Remove
support for a blocking 'upgrade'. It is no longer needed and it is
too dangerous to have anyway.
* Fix a deadlock which occurs when hammer2_chain_unlock() tries to
upgrade the 'last' shared lock to exclusive. This can deadlock if
another thread obtains the chain shared before we manage to do the
upgrade.
Just use a 'try' here. If it fails it means someone else got a lock
(of any kind) and we don't have to worry about dropping the chain data.
* Replace hammer2_mtx_upgrade() with hammer2_mtx_upgrade_try(). Remove
support for a blocking 'upgrade'. It is no longer needed and it is
too dangerous to have anyway.
| sys/vfs/hammer2/hammer2.h | diffblobblamehistory | |
| sys/vfs/hammer2/hammer2_chain.c | diffblobblamehistory |