From: "Yan, Zheng" <zheng.z.yan@xxxxxxxxx>
Both CInode and CDentry's versionlocks are of type LocalLock.
Acquiring LocalLock in replica object is useless and problematic.
For example, if two requests try acquiring a replica object's
versionlock, the first request succeeds, the second request
is added to wait queue. Later when the first request finishes,
MDCache::request_drop_foreign_locks() finds the lock's parent is
non-auth, it skips waking requests in the wait queue. So the
second request hangs.
Signed-off-by: Yan, Zheng <zheng.z.yan@xxxxxxxxx>
---
src/mds/Locker.cc | 6 ++++++
src/mds/Server.cc | 25 ++++++++++---------------
3 files changed, 17 insertions(+), 16 deletions(-)
diff --git a/src/mds/Locker.cc b/src/mds/Locker.cc
index e033bbe..6474743 100644
--- a/src/mds/Locker.cc
+++ b/src/mds/Locker.cc
@@ -196,6 +196,7 @@ bool Locker::acquire_locks(MDRequest *mdr,
// augment xlock with a versionlock?
if ((*p)->get_type() == CEPH_LOCK_DN) {
CDentry *dn = (CDentry*)(*p)->get_parent();
+ assert(dn->is_auth());
if (xlocks.count(&dn->versionlock))
continue; // we're xlocking the versionlock too; don't wrlock it!
@@ -213,6 +214,8 @@ bool Locker::acquire_locks(MDRequest *mdr,
if ((*p)->get_type() > CEPH_LOCK_IVERSION) {
// inode version lock?
CInode *in = (CInode*)(*p)->get_parent();
+ if (!in->is_auth())
+ continue;
if (mdr->is_master()) {
// master. wrlock versionlock so we can pipeline inode updates to journal.
wrlocks.insert(&in->versionlock);
@@ -3899,6 +3902,7 @@ void Locker::local_wrlock_grab(LocalLock *lock, Mutation *mut)
dout(7) << "local_wrlock_grab on " << *lock
<< " on " << *lock->get_parent() << dendl;
+ assert(lock->get_parent()->is_auth());
assert(lock->can_wrlock());
assert(!mut->wrlocks.count(lock));
lock->get_wrlock(mut->get_client());
@@ -3911,6 +3915,7 @@ bool Locker::local_wrlock_start(LocalLock *lock, MDRequest *mut)
dout(7) << "local_wrlock_start on " << *lock
<< " on " << *lock->get_parent() << dendl;
+ assert(lock->get_parent()->is_auth());
if (lock->can_wrlock()) {
assert(!mut->wrlocks.count(lock));
lock->get_wrlock(mut->get_client());
@@ -3942,6 +3947,7 @@ bool Locker::local_xlock_start(LocalLock *lock, MDRequest *mut)
dout(7) << "local_xlock_start on " << *lock
<< " on " << *lock->get_parent() << dendl;
+ assert(lock->get_parent()->is_auth());
if (!lock->can_xlock_local()) {
lock->add_waiter(SimpleLock::WAIT_WR|SimpleLock::WAIT_STABLE, new C_MDS_RetryRequest(mdcache, mut));
return false;
diff --git a/src/mds/Server.cc b/src/mds/Server.cc
index 4642a13..45c890a 100644
--- a/src/mds/Server.cc
+++ b/src/mds/Server.cc
@@ -5204,25 +5204,20 @@ void Server::handle_client_rename(MDRequest *mdr)
wrlocks.insert(&straydn->get_dir()->inode->nestlock);
}
- // xlock versionlock on srci if remote?
- // this ensures it gets safely remotely auth_pinned, avoiding deadlock;
- // strictly speaking, having the slave node freeze the inode is
- // otherwise sufficient for avoiding conflicts with inode locks, etc.
- if (!srcdn->is_auth() && srcdnl->is_primary()) // xlock versionlock on srci if there are any witnesses
- xlocks.insert(&srci->versionlock);
-
// xlock versionlock on dentries if there are witnesses.
// replicas can't see projected dentry linkages, and will get
// confused if we try to pipeline things.
if (!witnesses.empty()) {
- if (srcdn->is_projected())
- xlocks.insert(&srcdn->versionlock);
- if (destdn->is_projected())
- xlocks.insert(&destdn->versionlock);
- // also take rdlock on all ancestor dentries for destdn. this ensures that the
- // destdn can be traversed to by the witnesses.
- for (int i=0; i<(int)desttrace.size(); i++)
- xlocks.insert(&desttrace[i]->versionlock);
+ // take xlock on all projected dentries for srcdn and destdn. this ensures
+ // that the srcdn and destdn can be traversed to by the witnesses.
+ for (int i= 0; i<(int)srctrace.size(); i++) {
+ if (srctrace[i]->is_auth() && srctrace[i]->is_projected())
+ xlocks.insert(&srctrace[i]->versionlock);
+ }
+ for (int i=0; i<(int)desttrace.size(); i++) {
+ if (desttrace[i]->is_auth() && desttrace[i]->is_projected())
+ xlocks.insert(&desttrace[i]->versionlock);
+ }
}
// we need to update srci's ctime. xlock its least contended lock to do that...
--
1.7.11.7
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