--- /dev/null
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+#include <errno.h>
+
+#include "common/debug.h"
+#include "mdstypes.h"
+#include "mds/flock.h"
+
+#define dout_subsys ceph_subsys_mds
+
+static multimap<ceph_filelock, ceph_lock_state_t*> global_waiting_locks;
+
+static void remove_global_waiting(ceph_filelock &fl, ceph_lock_state_t *lock_state)
+{
+ for (auto p = global_waiting_locks.find(fl);
+ p != global_waiting_locks.end(); ) {
+ if (p->first != fl)
+ break;
+ if (p->second == lock_state) {
+ global_waiting_locks.erase(p);
+ break;
+ }
+ ++p;
+ }
+}
+
+ceph_lock_state_t::~ceph_lock_state_t()
+{
+ if (type == CEPH_LOCK_FCNTL) {
+ for (auto p = waiting_locks.begin(); p != waiting_locks.end(); ++p) {
+ remove_global_waiting(p->second, this);
+ }
+ }
+}
+
+bool ceph_lock_state_t::is_waiting(const ceph_filelock &fl) const
+{
+ multimap<uint64_t, ceph_filelock>::const_iterator p = waiting_locks.find(fl.start);
+ while (p != waiting_locks.end()) {
+ if (p->second.start > fl.start)
+ return false;
+ if (p->second.length == fl.length &&
+ ceph_filelock_owner_equal(p->second, fl))
+ return true;
+ ++p;
+ }
+ return false;
+}
+
+void ceph_lock_state_t::remove_waiting(const ceph_filelock& fl)
+{
+ for (auto p = waiting_locks.find(fl.start);
+ p != waiting_locks.end(); ) {
+ if (p->second.start > fl.start)
+ break;
+ if (p->second.length == fl.length &&
+ ceph_filelock_owner_equal(p->second, fl)) {
+ if (type == CEPH_LOCK_FCNTL) {
+ remove_global_waiting(p->second, this);
+ }
+ waiting_locks.erase(p);
+ --client_waiting_lock_counts[(client_t)fl.client];
+ if (!client_waiting_lock_counts[(client_t)fl.client]) {
+ client_waiting_lock_counts.erase((client_t)fl.client);
+ }
+ break;
+ }
+ ++p;
+ }
+}
+
+bool ceph_lock_state_t::is_deadlock(const ceph_filelock& fl,
+ list<multimap<uint64_t, ceph_filelock>::iterator>&
+ overlapping_locks,
+ const ceph_filelock *first_fl, unsigned depth) const
+{
+ ldout(cct,15) << "is_deadlock " << fl << dendl;
+
+ // only for posix lock
+ if (type != CEPH_LOCK_FCNTL)
+ return false;
+
+ // find conflict locks' owners
+ set<ceph_filelock> lock_owners;
+ for (auto p = overlapping_locks.begin();
+ p != overlapping_locks.end();
+ ++p) {
+
+ if (fl.type == CEPH_LOCK_SHARED &&
+ (*p)->second.type == CEPH_LOCK_SHARED)
+ continue;
+
+ // circle detected
+ if (first_fl && ceph_filelock_owner_equal(*first_fl, (*p)->second)) {
+ ldout(cct,15) << " detect deadlock" << dendl;
+ return true;
+ }
+
+ ceph_filelock tmp = (*p)->second;
+ tmp.start = 0;
+ tmp.length = 0;
+ tmp.type = 0;
+ lock_owners.insert(tmp);
+ }
+
+ if (depth >= MAX_DEADLK_DEPTH)
+ return false;
+
+ first_fl = first_fl ? first_fl : &fl;
+ for (auto p = lock_owners.begin();
+ p != lock_owners.end();
+ ++p) {
+ ldout(cct,15) << " conflict lock owner " << *p << dendl;
+ // if conflict lock' owner is waiting for other lock?
+ for (auto q = global_waiting_locks.lower_bound(*p);
+ q != global_waiting_locks.end();
+ ++q) {
+ if (!ceph_filelock_owner_equal(q->first, *p))
+ break;
+
+ list<multimap<uint64_t, ceph_filelock>::iterator>
+ _overlapping_locks, _self_overlapping_locks;
+ ceph_lock_state_t& state = *(q->second);
+ if (state.get_overlapping_locks(q->first, _overlapping_locks)) {
+ state.split_by_owner(q->first, _overlapping_locks, _self_overlapping_locks);
+ }
+ if (!_overlapping_locks.empty()) {
+ if (is_deadlock(q->first, _overlapping_locks, first_fl, depth + 1))
+ return true;
+ }
+ }
+ }
+ return false;
+}
+
+void ceph_lock_state_t::add_waiting(const ceph_filelock& fl)
+{
+ waiting_locks.insert(pair<uint64_t, ceph_filelock>(fl.start, fl));
+ ++client_waiting_lock_counts[(client_t)fl.client];
+ if (type == CEPH_LOCK_FCNTL) {
+ global_waiting_locks.insert(pair<ceph_filelock,ceph_lock_state_t*>(fl, this));
+ }
+}
+
+bool ceph_lock_state_t::add_lock(ceph_filelock& new_lock,
+ bool wait_on_fail, bool replay,
+ bool *deadlock)
+{
+ ldout(cct,15) << "add_lock " << new_lock << dendl;
+ bool ret = false;
+ list<multimap<uint64_t, ceph_filelock>::iterator>
+ overlapping_locks, self_overlapping_locks, neighbor_locks;
+
+ // first, get any overlapping locks and split them into owned-by-us and not
+ if (get_overlapping_locks(new_lock, overlapping_locks, &neighbor_locks)) {
+ ldout(cct,15) << "got overlapping lock, splitting by owner" << dendl;
+ split_by_owner(new_lock, overlapping_locks, self_overlapping_locks);
+ }
+ if (!overlapping_locks.empty()) { //overlapping locks owned by others :(
+ if (CEPH_LOCK_EXCL == new_lock.type) {
+ //can't set, we want an exclusive
+ ldout(cct,15) << "overlapping lock, and this lock is exclusive, can't set"
+ << dendl;
+ if (wait_on_fail && !replay) {
+ if (is_deadlock(new_lock, overlapping_locks))
+ *deadlock = true;
+ else
+ add_waiting(new_lock);
+ }
+ } else { //shared lock, check for any exclusive locks blocking us
+ if (contains_exclusive_lock(overlapping_locks)) { //blocked :(
+ ldout(cct,15) << " blocked by exclusive lock in overlapping_locks" << dendl;
+ if (wait_on_fail && !replay) {
+ if (is_deadlock(new_lock, overlapping_locks))
+ *deadlock = true;
+ else
+ add_waiting(new_lock);
+ }
+ } else {
+ //yay, we can insert a shared lock
+ ldout(cct,15) << "inserting shared lock" << dendl;
+ remove_waiting(new_lock);
+ adjust_locks(self_overlapping_locks, new_lock, neighbor_locks);
+ held_locks.insert(pair<uint64_t, ceph_filelock>(new_lock.start, new_lock));
+ ret = true;
+ }
+ }
+ } else { //no overlapping locks except our own
+ remove_waiting(new_lock);
+ adjust_locks(self_overlapping_locks, new_lock, neighbor_locks);
+ ldout(cct,15) << "no conflicts, inserting " << new_lock << dendl;
+ held_locks.insert(pair<uint64_t, ceph_filelock>
+ (new_lock.start, new_lock));
+ ret = true;
+ }
+ if (ret) {
+ ++client_held_lock_counts[(client_t)new_lock.client];
+ }
+ return ret;
+}
+
+void ceph_lock_state_t::look_for_lock(ceph_filelock& testing_lock)
+{
+ list<multimap<uint64_t, ceph_filelock>::iterator> overlapping_locks,
+ self_overlapping_locks;
+ if (get_overlapping_locks(testing_lock, overlapping_locks)) {
+ split_by_owner(testing_lock, overlapping_locks, self_overlapping_locks);
+ }
+ if (!overlapping_locks.empty()) { //somebody else owns overlapping lock
+ if (CEPH_LOCK_EXCL == testing_lock.type) { //any lock blocks it
+ testing_lock = (*overlapping_locks.begin())->second;
+ } else {
+ ceph_filelock *blocking_lock;
+ if ((blocking_lock = contains_exclusive_lock(overlapping_locks))) {
+ testing_lock = *blocking_lock;
+ } else { //nothing blocking!
+ testing_lock.type = CEPH_LOCK_UNLOCK;
+ }
+ }
+ return;
+ }
+ //if we get here, only our own locks block
+ testing_lock.type = CEPH_LOCK_UNLOCK;
+}
+
+void ceph_lock_state_t::remove_lock(ceph_filelock removal_lock,
+ list<ceph_filelock>& activated_locks)
+{
+ list<multimap<uint64_t, ceph_filelock>::iterator> overlapping_locks,
+ self_overlapping_locks;
+ if (get_overlapping_locks(removal_lock, overlapping_locks)) {
+ ldout(cct,15) << "splitting by owner" << dendl;
+ split_by_owner(removal_lock, overlapping_locks, self_overlapping_locks);
+ } else ldout(cct,15) << "attempt to remove lock at " << removal_lock.start
+ << " but no locks there!" << dendl;
+ bool remove_to_end = (0 == removal_lock.length);
+ uint64_t removal_start = removal_lock.start;
+ uint64_t removal_end = removal_start + removal_lock.length - 1;
+ __s64 old_lock_client = 0;
+ ceph_filelock *old_lock;
+
+ ldout(cct,15) << "examining " << self_overlapping_locks.size()
+ << " self-overlapping locks for removal" << dendl;
+ for (list<multimap<uint64_t, ceph_filelock>::iterator>::iterator
+ iter = self_overlapping_locks.begin();
+ iter != self_overlapping_locks.end();
+ ++iter) {
+ ldout(cct,15) << "self overlapping lock " << (*iter)->second << dendl;
+ old_lock = &(*iter)->second;
+ bool old_lock_to_end = (0 == old_lock->length);
+ uint64_t old_lock_end = old_lock->start + old_lock->length - 1;
+ old_lock_client = old_lock->client;
+ if (remove_to_end) {
+ if (old_lock->start < removal_start) {
+ old_lock->length = removal_start - old_lock->start;
+ } else {
+ ldout(cct,15) << "erasing " << (*iter)->second << dendl;
+ held_locks.erase(*iter);
+ --client_held_lock_counts[old_lock_client];
+ }
+ } else if (old_lock_to_end) {
+ ceph_filelock append_lock = *old_lock;
+ append_lock.start = removal_end+1;
+ held_locks.insert(pair<uint64_t, ceph_filelock>
+ (append_lock.start, append_lock));
+ ++client_held_lock_counts[(client_t)old_lock->client];
+ if (old_lock->start >= removal_start) {
+ ldout(cct,15) << "erasing " << (*iter)->second << dendl;
+ held_locks.erase(*iter);
+ --client_held_lock_counts[old_lock_client];
+ } else old_lock->length = removal_start - old_lock->start;
+ } else {
+ if (old_lock_end > removal_end) {
+ ceph_filelock append_lock = *old_lock;
+ append_lock.start = removal_end + 1;
+ append_lock.length = old_lock_end - append_lock.start + 1;
+ held_locks.insert(pair<uint64_t, ceph_filelock>
+ (append_lock.start, append_lock));
+ ++client_held_lock_counts[(client_t)old_lock->client];
+ }
+ if (old_lock->start < removal_start) {
+ old_lock->length = removal_start - old_lock->start;
+ } else {
+ ldout(cct,15) << "erasing " << (*iter)->second << dendl;
+ held_locks.erase(*iter);
+ --client_held_lock_counts[old_lock_client];
+ }
+ }
+ if (!client_held_lock_counts[old_lock_client]) {
+ client_held_lock_counts.erase(old_lock_client);
+ }
+ }
+}
+
+bool ceph_lock_state_t::remove_all_from (client_t client)
+{
+ bool cleared_any = false;
+ if (client_held_lock_counts.count(client)) {
+ multimap<uint64_t, ceph_filelock>::iterator iter = held_locks.begin();
+ while (iter != held_locks.end()) {
+ if ((client_t)iter->second.client == client) {
+ held_locks.erase(iter++);
+ } else
+ ++iter;
+ }
+ client_held_lock_counts.erase(client);
+ cleared_any = true;
+ }
+
+ if (client_waiting_lock_counts.count(client)) {
+ multimap<uint64_t, ceph_filelock>::iterator iter = waiting_locks.begin();
+ while (iter != waiting_locks.end()) {
+ if ((client_t)iter->second.client != client) {
+ ++iter;
+ continue;
+ }
+ if (type == CEPH_LOCK_FCNTL) {
+ remove_global_waiting(iter->second, this);
+ }
+ waiting_locks.erase(iter++);
+ }
+ client_waiting_lock_counts.erase(client);
+ }
+ return cleared_any;
+}
+
+void ceph_lock_state_t::adjust_locks(list<multimap<uint64_t, ceph_filelock>::iterator> old_locks,
+ ceph_filelock& new_lock,
+ list<multimap<uint64_t, ceph_filelock>::iterator>
+ neighbor_locks)
+{
+ ldout(cct,15) << "adjust_locks" << dendl;
+ bool new_lock_to_end = (0 == new_lock.length);
+ __s64 old_lock_client = 0;
+ ceph_filelock *old_lock;
+ for (list<multimap<uint64_t, ceph_filelock>::iterator>::iterator
+ iter = old_locks.begin();
+ iter != old_locks.end();
+ ++iter) {
+ old_lock = &(*iter)->second;
+ ldout(cct,15) << "adjusting lock: " << *old_lock << dendl;
+ bool old_lock_to_end = (0 == old_lock->length);
+ uint64_t old_lock_start = old_lock->start;
+ uint64_t old_lock_end = old_lock->start + old_lock->length - 1;
+ uint64_t new_lock_start = new_lock.start;
+ uint64_t new_lock_end = new_lock.start + new_lock.length - 1;
+ old_lock_client = old_lock->client;
+ if (new_lock_to_end || old_lock_to_end) {
+ //special code path to deal with a length set at 0
+ ldout(cct,15) << "one lock extends forever" << dendl;
+ if (old_lock->type == new_lock.type) {
+ //just unify them in new lock, remove old lock
+ ldout(cct,15) << "same lock type, unifying" << dendl;
+ new_lock.start = (new_lock_start < old_lock_start) ? new_lock_start :
+ old_lock_start;
+ new_lock.length = 0;
+ held_locks.erase(*iter);
+ --client_held_lock_counts[old_lock_client];
+ } else { //not same type, have to keep any remains of old lock around
+ ldout(cct,15) << "shrinking old lock" << dendl;
+ if (new_lock_to_end) {
+ if (old_lock_start < new_lock_start) {
+ old_lock->length = new_lock_start - old_lock_start;
+ } else {
+ held_locks.erase(*iter);
+ --client_held_lock_counts[old_lock_client];
+ }
+ } else { //old lock extends past end of new lock
+ ceph_filelock appended_lock = *old_lock;
+ appended_lock.start = new_lock_end + 1;
+ held_locks.insert(pair<uint64_t, ceph_filelock>
+ (appended_lock.start, appended_lock));
+ ++client_held_lock_counts[(client_t)old_lock->client];
+ if (old_lock_start < new_lock_start) {
+ old_lock->length = new_lock_start - old_lock_start;
+ } else {
+ held_locks.erase(*iter);
+ --client_held_lock_counts[old_lock_client];
+ }
+ }
+ }
+ } else {
+ if (old_lock->type == new_lock.type) { //just merge them!
+ ldout(cct,15) << "merging locks, they're the same type" << dendl;
+ new_lock.start = (old_lock_start < new_lock_start ) ? old_lock_start :
+ new_lock_start;
+ int new_end = (new_lock_end > old_lock_end) ? new_lock_end :
+ old_lock_end;
+ new_lock.length = new_end - new_lock.start + 1;
+ ldout(cct,15) << "erasing lock " << (*iter)->second << dendl;
+ held_locks.erase(*iter);
+ --client_held_lock_counts[old_lock_client];
+ } else { //we'll have to update sizes and maybe make new locks
+ ldout(cct,15) << "locks aren't same type, changing sizes" << dendl;
+ if (old_lock_end > new_lock_end) { //add extra lock after new_lock
+ ceph_filelock appended_lock = *old_lock;
+ appended_lock.start = new_lock_end + 1;
+ appended_lock.length = old_lock_end - appended_lock.start + 1;
+ held_locks.insert(pair<uint64_t, ceph_filelock>
+ (appended_lock.start, appended_lock));
+ ++client_held_lock_counts[(client_t)old_lock->client];
+ }
+ if (old_lock_start < new_lock_start) {
+ old_lock->length = new_lock_start - old_lock_start;
+ } else { //old_lock starts inside new_lock, so remove it
+ //if it extended past new_lock_end it's been replaced
+ held_locks.erase(*iter);
+ --client_held_lock_counts[old_lock_client];
+ }
+ }
+ }
+ if (!client_held_lock_counts[old_lock_client]) {
+ client_held_lock_counts.erase(old_lock_client);
+ }
+ }
+
+ //make sure to coalesce neighboring locks
+ for (list<multimap<uint64_t, ceph_filelock>::iterator>::iterator
+ iter = neighbor_locks.begin();
+ iter != neighbor_locks.end();
+ ++iter) {
+ old_lock = &(*iter)->second;
+ old_lock_client = old_lock->client;
+ ldout(cct,15) << "lock to coalesce: " << *old_lock << dendl;
+ /* because if it's a neighboring lock there can't be any self-overlapping
+ locks that covered it */
+ if (old_lock->type == new_lock.type) { //merge them
+ if (0 == new_lock.length) {
+ if (old_lock->start + old_lock->length == new_lock.start) {
+ new_lock.start = old_lock->start;
+ } else ceph_abort(); /* if there's no end to new_lock, the neighbor
+ HAS TO be to left side */
+ } else if (0 == old_lock->length) {
+ if (new_lock.start + new_lock.length == old_lock->start) {
+ new_lock.length = 0;
+ } else ceph_abort(); //same as before, but reversed
+ } else {
+ if (old_lock->start + old_lock->length == new_lock.start) {
+ new_lock.start = old_lock->start;
+ new_lock.length = old_lock->length + new_lock.length;
+ } else if (new_lock.start + new_lock.length == old_lock->start) {
+ new_lock.length = old_lock->length + new_lock.length;
+ }
+ }
+ held_locks.erase(*iter);
+ --client_held_lock_counts[old_lock_client];
+ }
+ if (!client_held_lock_counts[old_lock_client]) {
+ client_held_lock_counts.erase(old_lock_client);
+ }
+ }
+}
+
+multimap<uint64_t, ceph_filelock>::iterator
+ceph_lock_state_t::get_lower_bound(uint64_t start,
+ multimap<uint64_t, ceph_filelock>& lock_map)
+{
+ multimap<uint64_t, ceph_filelock>::iterator lower_bound =
+ lock_map.lower_bound(start);
+ if ((lower_bound->first != start)
+ && (start != 0)
+ && (lower_bound != lock_map.begin())) --lower_bound;
+ if (lock_map.end() == lower_bound)
+ ldout(cct,15) << "get_lower_dout(15)eturning end()" << dendl;
+ else ldout(cct,15) << "get_lower_bound returning iterator pointing to "
+ << lower_bound->second << dendl;
+ return lower_bound;
+ }
+
+multimap<uint64_t, ceph_filelock>::iterator
+ceph_lock_state_t::get_last_before(uint64_t end,
+ multimap<uint64_t, ceph_filelock>& lock_map)
+{
+ multimap<uint64_t, ceph_filelock>::iterator last =
+ lock_map.upper_bound(end);
+ if (last != lock_map.begin()) --last;
+ if (lock_map.end() == last)
+ ldout(cct,15) << "get_last_before returning end()" << dendl;
+ else ldout(cct,15) << "get_last_before returning iterator pointing to "
+ << last->second << dendl;
+ return last;
+}
+
+bool ceph_lock_state_t::share_space(
+ multimap<uint64_t, ceph_filelock>::iterator& iter,
+ uint64_t start, uint64_t end)
+{
+ bool ret = ((iter->first >= start && iter->first <= end) ||
+ ((iter->first < start) &&
+ (((iter->first + iter->second.length - 1) >= start) ||
+ (0 == iter->second.length))));
+ ldout(cct,15) << "share_space got start: " << start << ", end: " << end
+ << ", lock: " << iter->second << ", returning " << ret << dendl;
+ return ret;
+}
+
+bool ceph_lock_state_t::get_overlapping_locks(const ceph_filelock& lock,
+ list<multimap<uint64_t,
+ ceph_filelock>::iterator> & overlaps,
+ list<multimap<uint64_t,
+ ceph_filelock>::iterator> *self_neighbors)
+{
+ ldout(cct,15) << "get_overlapping_locks" << dendl;
+ // create a lock starting one earlier and ending one later
+ // to check for neighbors
+ ceph_filelock neighbor_check_lock = lock;
+ if (neighbor_check_lock.start != 0) {
+ neighbor_check_lock.start = neighbor_check_lock.start - 1;
+ if (neighbor_check_lock.length)
+ neighbor_check_lock.length = neighbor_check_lock.length + 2;
+ } else {
+ if (neighbor_check_lock.length)
+ neighbor_check_lock.length = neighbor_check_lock.length + 1;
+ }
+ //find the last held lock starting at the point after lock
+ uint64_t endpoint = lock.start;
+ if (lock.length) {
+ endpoint += lock.length;
+ } else {
+ endpoint = uint64_t(-1); // max offset
+ }
+ multimap<uint64_t, ceph_filelock>::iterator iter =
+ get_last_before(endpoint, held_locks);
+ bool cont = iter != held_locks.end();
+ while(cont) {
+ if (share_space(iter, lock)) {
+ overlaps.push_front(iter);
+ } else if (self_neighbors &&
+ ceph_filelock_owner_equal(neighbor_check_lock, iter->second) &&
+ share_space(iter, neighbor_check_lock)) {
+ self_neighbors->push_front(iter);
+ }
+ if ((iter->first < lock.start) && (CEPH_LOCK_EXCL == iter->second.type)) {
+ //can't be any more overlapping locks or they'd interfere with this one
+ cont = false;
+ } else if (held_locks.begin() == iter) cont = false;
+ else --iter;
+ }
+ return !overlaps.empty();
+}
+
+bool ceph_lock_state_t::get_waiting_overlaps(const ceph_filelock& lock,
+ list<multimap<uint64_t,
+ ceph_filelock>::iterator>&
+ overlaps)
+{
+ ldout(cct,15) << "get_waiting_overlaps" << dendl;
+ multimap<uint64_t, ceph_filelock>::iterator iter =
+ get_last_before(lock.start + lock.length - 1, waiting_locks);
+ bool cont = iter != waiting_locks.end();
+ while(cont) {
+ if (share_space(iter, lock)) overlaps.push_front(iter);
+ if (waiting_locks.begin() == iter) cont = false;
+ --iter;
+ }
+ return !overlaps.empty();
+}
+
+void ceph_lock_state_t::split_by_owner(const ceph_filelock& owner,
+ list<multimap<uint64_t,
+ ceph_filelock>::iterator>& locks,
+ list<multimap<uint64_t,
+ ceph_filelock>::iterator>&
+ owned_locks)
+{
+ list<multimap<uint64_t, ceph_filelock>::iterator>::iterator
+ iter = locks.begin();
+ ldout(cct,15) << "owner lock: " << owner << dendl;
+ while (iter != locks.end()) {
+ ldout(cct,15) << "comparing to " << (*iter)->second << dendl;
+ if (ceph_filelock_owner_equal((*iter)->second, owner)) {
+ ldout(cct,15) << "success, pushing to owned_locks" << dendl;
+ owned_locks.push_back(*iter);
+ iter = locks.erase(iter);
+ } else {
+ ldout(cct,15) << "failure, something not equal in this group "
+ << (*iter)->second.client << ":" << owner.client << ","
+ << (*iter)->second.owner << ":" << owner.owner << ","
+ << (*iter)->second.pid << ":" << owner.pid << dendl;
+ ++iter;
+ }
+ }
+}
+
+ceph_filelock *
+ceph_lock_state_t::contains_exclusive_lock(list<multimap<uint64_t,
+ ceph_filelock>::iterator>& locks)
+{
+ for (list<multimap<uint64_t, ceph_filelock>::iterator>::iterator
+ iter = locks.begin();
+ iter != locks.end();
+ ++iter) {
+ if (CEPH_LOCK_EXCL == (*iter)->second.type) return &(*iter)->second;
+ }
+ return NULL;
+}
Code Review / stor4nfv.git / blobdiff