diff options
author | Yan, Zheng <zheng.z.yan@intel.com> | 2013-07-16 15:21:38 +0800 |
---|---|---|
committer | Yan, Zheng <zheng.z.yan@intel.com> | 2013-08-05 11:09:07 +0800 |
commit | 3c3b2ceb03e7294704f5bf3e1e420012a0166585 (patch) | |
tree | 24da8a12c4b4b5b04256c5562646f65fe6ee3148 | |
parent | 755581977c2bc9eb81c9d9d955024cbedded2161 (diff) | |
download | ceph-3c3b2ceb03e7294704f5bf3e1e420012a0166585.tar.gz |
mds: revoke GSHARED cap when finishing xlock
If lock state is LOCK_XLOCKDONE, the xlocker can have GSHARED cap.
So when finishing xlock, we may need to revoke the GSHARED cap.
In most cases Locker::_finish_xlock() directly set lock state to
LOCK_LOCK or LOCK_EXCL, which hides the issue. If 'num_rdlock > 0'
or 'num_wrlock > 0' when finishing xlock, the issue reveals.
(lock get stuck in LOCK_XLOCKDONE forever)
The fix is always call Locker::_finish_xlock() when xlock count
reaches zero. _finish_xlock() checks if it can change lock state
to LOCK_EXCL immediately. If not, it uses Locker::eval_gather()
to transit lock state.
Another change of this patch is avoid changing lock state to
LOCK_LOCK directly. because lock in LOCK_XLOCK_DONE state allows
GSHARED cap, lock in LOCK_LOCK state does not.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
-rw-r--r-- | src/mds/Locker.cc | 57 | ||||
-rw-r--r-- | src/mds/Locker.h | 2 |
2 files changed, 27 insertions, 32 deletions
diff --git a/src/mds/Locker.cc b/src/mds/Locker.cc index 30e014ab785..254bbb2044b 100644 --- a/src/mds/Locker.cc +++ b/src/mds/Locker.cc @@ -546,9 +546,7 @@ void Locker::cancel_locking(Mutation *mut, set<CInode*> *pneed_issue) if (lock->get_type() != CEPH_LOCK_DN) { bool need_issue = false; if (lock->get_state() == LOCK_PREXLOCK) - _finish_xlock(lock, &need_issue); - if (lock->is_stable()) - eval(lock, &need_issue); + _finish_xlock(lock, -1, &need_issue); if (need_issue) pneed_issue->insert(static_cast<CInode *>(lock->get_parent())); } @@ -1458,19 +1456,29 @@ bool Locker::xlock_start(SimpleLock *lock, MDRequest *mut) } } -void Locker::_finish_xlock(SimpleLock *lock, bool *pneed_issue) +void Locker::_finish_xlock(SimpleLock *lock, client_t xlocker, bool *pneed_issue) { assert(!lock->is_stable()); - if (lock->get_type() != CEPH_LOCK_DN && (static_cast<CInode*>(lock->get_parent())->get_loner()) >= 0) - lock->set_state(LOCK_EXCL); - else - lock->set_state(LOCK_LOCK); - if (lock->get_type() == CEPH_LOCK_DN && lock->get_parent()->is_replicated() && - !lock->is_waiter_for(SimpleLock::WAIT_WR)) - simple_sync(lock, pneed_issue); - if (lock->get_cap_shift()) - *pneed_issue = true; - lock->get_parent()->auth_unpin(lock); + if (lock->get_num_rdlocks() == 0 && + lock->get_num_wrlocks() == 0 && + lock->get_num_client_lease() == 0 && + lock->get_type() != CEPH_LOCK_DN) { + CInode *in = static_cast<CInode*>(lock->get_parent()); + client_t loner = in->get_target_loner(); + if (loner >= 0 && (xlocker < 0 || xlocker == loner)) { + lock->set_state(LOCK_EXCL); + lock->get_parent()->auth_unpin(lock); + lock->finish_waiters(SimpleLock::WAIT_STABLE|SimpleLock::WAIT_WR|SimpleLock::WAIT_RD); + if (lock->get_cap_shift()) + *pneed_issue = true; + if (lock->get_parent()->is_auth() && + lock->is_stable()) + try_eval(lock, pneed_issue); + return; + } + } + // the xlocker may have CEPH_CAP_GSHARED, need to revoke it if next state is LOCK_LOCK + eval_gather(lock, true, pneed_issue); } void Locker::xlock_finish(SimpleLock *lock, Mutation *mut, bool *pneed_issue) @@ -1481,6 +1489,8 @@ void Locker::xlock_finish(SimpleLock *lock, Mutation *mut, bool *pneed_issue) dout(10) << "xlock_finish on " << *lock << " " << *lock->get_parent() << dendl; + client_t xlocker = lock->get_xlock_by_client(); + // drop ref lock->put_xlock(); assert(mut); @@ -1508,24 +1518,9 @@ void Locker::xlock_finish(SimpleLock *lock, Mutation *mut, bool *pneed_issue) SimpleLock::WAIT_WR | SimpleLock::WAIT_RD, 0); } else { - if (lock->get_num_xlocks() == 0 && - lock->get_num_rdlocks() == 0 && - lock->get_num_wrlocks() == 0 && - lock->get_num_client_lease() == 0) { - _finish_xlock(lock, &do_issue); - } - - // others waiting? - lock->finish_waiters(SimpleLock::WAIT_STABLE | - SimpleLock::WAIT_WR | - SimpleLock::WAIT_RD, 0); + if (lock->get_num_xlocks() == 0) + _finish_xlock(lock, xlocker, &do_issue); } - - // eval? - if (!lock->is_stable()) - eval_gather(lock, false, &do_issue); - else if (lock->get_parent()->is_auth()) - try_eval(lock, &do_issue); if (do_issue) { CInode *in = static_cast<CInode*>(lock->get_parent()); diff --git a/src/mds/Locker.h b/src/mds/Locker.h index b97307d6cb2..b39eff175d6 100644 --- a/src/mds/Locker.h +++ b/src/mds/Locker.h @@ -143,7 +143,7 @@ public: void remote_wrlock_finish(SimpleLock *lock, int target, Mutation *mut); bool xlock_start(SimpleLock *lock, MDRequest *mut); - void _finish_xlock(SimpleLock *lock, bool *pneed_issue); + void _finish_xlock(SimpleLock *lock, client_t xlocker, bool *pneed_issue); void xlock_finish(SimpleLock *lock, Mutation *mut, bool *pneed_issue); void xlock_export(SimpleLock *lock, Mutation *mut); |