From: "Yan, Zheng" <zheng.z.yan@xxxxxxxxx>
commit 0071b8e75b (mds: stay in SCAN state in file_eval) makes
Locker::file_eval() ignore lock in LOCK_SCAN state. If there
is no request changes the lock state, the lock can be stuck in
LOCK_SCAN state forever. This can cause client read/write hang
because lock in LOCK_SCAN state does not allow Frw caps.
The fix is change LOCK_SCAN to a unstable state. Thank to the
CInode::STATE_RECOVERING check in Locker::eval_gather(), the
lock stays in the SCAN state while file is being recovering.
The lock will transit to a stable state once the recovery
finishes.
Signed-off-by: Yan, Zheng <zheng.z.yan@xxxxxxxxx>
---
src/mds/Locker.cc | 18 +++++-------------
src/mds/MDCache.cc | 1 +
src/mds/locks.c | 3 +--
src/mds/locks.h | 1 -
4 files changed, 7 insertions(+), 16 deletions(-)
diff --git a/src/mds/Locker.cc b/src/mds/Locker.cc
index efb5a74..084d64a 100644
--- a/src/mds/Locker.cc
+++ b/src/mds/Locker.cc
@@ -3441,7 +3441,6 @@ bool Locker::simple_sync(SimpleLock *lock, bool *need_issue)
switch (lock->get_state()) {
case LOCK_MIX: lock->set_state(LOCK_MIX_SYNC); break;
- case LOCK_SCAN:
case LOCK_LOCK: lock->set_state(LOCK_LOCK_SYNC); break;
case LOCK_XSYN: lock->set_state(LOCK_XSYN_SYNC); break;
case LOCK_EXCL: lock->set_state(LOCK_EXCL_SYNC); break;
@@ -3518,7 +3517,6 @@ void Locker::simple_excl(SimpleLock *lock, bool *need_issue)
in = static_cast<CInode *>(lock->get_parent());
switch (lock->get_state()) {
- case LOCK_SCAN:
case LOCK_LOCK: lock->set_state(LOCK_LOCK_EXCL); break;
case LOCK_SYNC: lock->set_state(LOCK_SYNC_EXCL); break;
case LOCK_XSYN: lock->set_state(LOCK_XSYN_EXCL); break;
@@ -3577,7 +3575,6 @@ void Locker::simple_lock(SimpleLock *lock, bool *need_issue)
int old_state = lock->get_state();
switch (lock->get_state()) {
- case LOCK_SCAN: lock->set_state(LOCK_SCAN_LOCK); break;
case LOCK_SYNC: lock->set_state(LOCK_SYNC_LOCK); break;
case LOCK_XSYN:
file_excl(static_cast<ScatterLock*>(lock), need_issue);
@@ -4163,10 +4160,6 @@ void Locker::file_eval(ScatterLock *lock, bool *need_issue)
if (lock->get_parent()->is_freezing_or_frozen())
return;
- // wait for scan
- if (lock->get_state() == LOCK_SCAN)
- return;
-
// excl -> *?
if (lock->get_state() == LOCK_EXCL) {
dout(20) << " is excl" << dendl;
@@ -4353,7 +4346,6 @@ void Locker::file_excl(ScatterLock *lock, bool *need_issue)
switch (lock->get_state()) {
case LOCK_SYNC: lock->set_state(LOCK_SYNC_EXCL); break;
case LOCK_MIX: lock->set_state(LOCK_MIX_EXCL); break;
- case LOCK_SCAN:
case LOCK_LOCK: lock->set_state(LOCK_LOCK_EXCL); break;
case LOCK_XSYN: lock->set_state(LOCK_XSYN_EXCL); break;
default: assert(0);
@@ -4464,12 +4456,12 @@ void Locker::file_recover(ScatterLock *lock)
issue_caps(in);
gather++;
}
- if (gather) {
- lock->get_parent()->auth_pin(lock);
- } else {
- lock->set_state(LOCK_SCAN);
+
+ lock->set_state(LOCK_SCAN);
+ if (gather)
+ in->state_set(CInode::STATE_NEEDSRECOVER);
+ else
mds->mdcache->queue_file_recover(in);
- }
}
diff --git a/src/mds/MDCache.cc b/src/mds/MDCache.cc
index 77d3d8b..898dcd3 100644
--- a/src/mds/MDCache.cc
+++ b/src/mds/MDCache.cc
@@ -5718,6 +5718,7 @@ void MDCache::identify_files_to_recover(vector<CInode*>& recover_q, vector<CInod
}
if (recover) {
+ in->auth_pin(&in->filelock);
in->filelock.set_state(LOCK_PRE_SCAN);
recover_q.push_back(in);
diff --git a/src/mds/locks.c b/src/mds/locks.c
index 9031087..37e3f5e 100644
--- a/src/mds/locks.c
+++ b/src/mds/locks.c
@@ -122,8 +122,7 @@ const struct sm_state_t filelock[LOCK_MAX] = {
[LOCK_EXCL_XSYN] = { LOCK_XSYN, false, LOCK_LOCK, 0, 0, XCL, 0, 0, 0, 0, 0,CEPH_CAP_GCACHE|CEPH_CAP_GBUFFER,0,0 },
[LOCK_PRE_SCAN] = { LOCK_SCAN, false, LOCK_LOCK, 0, 0, 0, 0, 0, 0, 0, 0,0,0,0 },
- [LOCK_SCAN] = { 0, false, LOCK_LOCK, 0, 0, 0, 0, 0, 0, 0, 0,0,0,0 },
- [LOCK_SCAN_LOCK] = { LOCK_LOCK, false, LOCK_LOCK, 0, 0, 0, 0, 0, 0, 0, 0,0,0,0 },
+ [LOCK_SCAN] = { LOCK_LOCK, false, LOCK_LOCK, 0, 0, 0, 0, 0, 0, 0, 0,0,0,0 },
};
const struct sm_t sm_filelock = {
diff --git a/src/mds/locks.h b/src/mds/locks.h
index 2adcbf2..d1585ce 100644
--- a/src/mds/locks.h
+++ b/src/mds/locks.h
@@ -86,7 +86,6 @@ enum {
LOCK_PRE_SCAN,
LOCK_SCAN,
- LOCK_SCAN_LOCK,
LOCK_SNAP_SYNC,
--
1.8.1.4
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