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mds: throttle purge stray operations

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Pull out the stray-handling code into a separate StrayManager
class.

There is an additional improvement to stray reintegration here,
by passing the DN that triggered the reintegration through,
we should make a better choice about *which* hardlink to
reintegrate the inode into, rather than just picking the first.

Fixes: #10390
Signed-off-by: John Spray <john.spray@redhat.com>
This commit is contained in:
John Spray 2015-01-20 12:17:56 +00:00
parent de157d9476
commit 2f1e10c11a
9 changed files with 1177 additions and 525 deletions
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1
src/mds/CDentry.h
View File

@ -152,6 +152,7 @@ protected:
friend class Migrator;
friend class Locker;
friend class MDCache;
friend class StrayManager;
friend class CInode;
friend class C_MDC_XlockRequest;

16
src/mds/CDir.cc
View File

@ -670,8 +670,13 @@ void CDir::remove_null_dentries() {
assert(get_num_any() == items.size());
}
// remove dirty null dentries for deleted directory. the dirfrag will be
// deleted soon, so it's safe to not commit dirty dentries.
/** remove dirty null dentries for deleted directory. the dirfrag will be
* deleted soon, so it's safe to not commit dirty dentries.
*
* This is called when a directory is being deleted, a prerequisite
* of which is that its children have been unlinked: we expect to only see
* null, unprojected dentries here.
*/
void CDir::try_remove_dentries_for_stray()
{
dout(10) << __func__ << dendl;
@ -685,8 +690,8 @@ void CDir::try_remove_dentries_for_stray()
CDentry *dn = p->second;
++p;
if (dn->last == CEPH_NOSNAP) {
if (!dn->get_linkage()->is_null() || dn->is_projected())
continue; // shouldn't happen
assert(!dn->is_projected());
assert(dn->get_linkage()->is_null());
if (clear_dirty && dn->is_dirty())
dn->mark_clean();
// It's OK to remove lease prematurely because we will never link
@ -696,8 +701,7 @@ void CDir::try_remove_dentries_for_stray()
if (dn->get_num_ref() == 0)
remove_dentry(dn);
} else {
if (dn->is_projected())
continue; // shouldn't happen
assert(!dn->is_projected());
CDentry::linkage_t *dnl= dn->get_linkage();
CInode *in = NULL;
if (dnl->is_primary()) {

1
src/mds/CInode.h
View File

@ -523,6 +523,7 @@ public:
friend class Locker;
friend class Migrator;
friend class MDCache;
friend class StrayManager;
friend class CDir;
friend class CInodeExport;

590
src/mds/MDCache.cc
View File

@ -168,11 +168,8 @@ public:
MDCache::MDCache(MDS *m) :
logger(0),
num_strays(0),
num_strays_purging(0),
num_strays_delayed(0),
recovery_queue(m),
delayed_eval_stray(member_offset(CDentry, item_stray))
stray_manager(m)
{
mds = m;
migrator = new Migrator(mds, this);
@ -711,14 +708,15 @@ CDentry *MDCache::get_or_create_stray_dentry(CInode *in)
if (!straydn) {
straydn = straydir->add_null_dentry(straydname);
straydn->mark_new();
num_strays++;
logger->set(l_mdc_num_strays, num_strays);
logger->inc(l_mdc_strays_created);
} else {
assert(straydn->get_projected_linkage()->is_null());
}
// Notify even if a null dentry already existed, because
// StrayManager counts the number of stray inodes, not the
// number of dentries in the directory.
stray_manager.notify_stray_created();
straydn->state_set(CDentry::STATE_STRAY);
return straydn;
}
@ -6187,14 +6185,7 @@ bool MDCache::trim(int max, int count)
dout(7) << "trim max=" << max << " cur=" << lru.lru_get_size() << dendl;
// process delayed eval_stray()
for (elist<CDentry*>::iterator p = delayed_eval_stray.begin(); !p.end(); ) {
CDentry *dn = *p;
++p;
dn->item_stray.remove_myself();
num_strays_delayed--;
eval_stray(dn);
}
logger->set(l_mdc_num_strays_delayed, num_strays_delayed);
stray_manager.advance_delayed();
map<mds_rank_t, MCacheExpire*> expiremap;
bool is_standby_replay = mds->is_standby_replay();
@ -6456,6 +6447,11 @@ void MDCache::trim_dirfrag(CDir *dir, CDir *con, map<mds_rank_t, MCacheExpire*>&
in->close_dirfrag(dir->dirfrag().frag);
}
/**
* Try trimming an inode from the cache
*
* @return true if the inode is still in cache, else false if it was trimmed
*/
bool MDCache::trim_inode(CDentry *dn, CInode *in, CDir *con, map<mds_rank_t, MCacheExpire*>& expiremap)
{
dout(15) << "trim_inode " << *in << dendl;
@ -6485,11 +6481,14 @@ bool MDCache::trim_inode(CDentry *dn, CInode *in, CDir *con, map<mds_rank_t, MCa
// INODE
if (in->is_auth()) {
// eval stray after closing dirfrags
if (dn && !mds->is_standby_replay()) {
if (dn) {
maybe_eval_stray(in);
if (dn->get_num_ref() > 0)
if (dn->get_num_ref() > 0) {
// Independent of whether we passed this on to the purge queue,
// if it still has refs then don't count it as trimmed
return true;
}
}
} else {
mds_authority_t auth = in->authority();
@ -7402,9 +7401,12 @@ bool MDCache::shutdown_export_strays()
strays[i]->get_dirfrags(dfs);
}
while (!dfs.empty()) {
CDir *dir = dfs.front();
dfs.pop_front();
stray_manager.abort_queue();
for (std::list<CDir*>::iterator dfs_i = dfs.begin();
dfs_i != dfs.end(); ++dfs_i)
{
CDir *dir = *dfs_i;
if (!dir->is_complete()) {
dir->fetch(0);
@ -7419,10 +7421,16 @@ bool MDCache::shutdown_export_strays()
if (dnl->is_null()) continue;
done = false;
if (dn->state_test(CDentry::STATE_PURGING)) {
// Don't try to migrate anything that is actually
// being purged right now
continue;
}
// FIXME: we'll deadlock if a rename fails.
if (exported_strays.count(dnl->get_inode()->ino()) == 0) {
exported_strays.insert(dnl->get_inode()->ino());
migrate_stray(dn, mds_rank_t(0)); // send to root!
stray_manager.migrate_stray(dn, mds_rank_t(0)); // send to root!
} else {
dout(10) << "already exporting " << *dn << dendl;
}
@ -9086,142 +9094,59 @@ void MDCache::scan_stray_dir(dirfrag_t next)
for (CDir::map_t::iterator q = dir->items.begin(); q != dir->items.end(); ++q) {
CDentry *dn = q->second;
CDentry::linkage_t *dnl = dn->get_projected_linkage();
num_strays++;
if (dnl->is_primary())
stray_manager.notify_stray_created();
if (dnl->is_primary()) {
maybe_eval_stray(dnl->get_inode());
}
}
}
struct C_MDC_EvalStray : public MDCacheContext {
CDentry *dn;
C_MDC_EvalStray(MDCache *c, CDentry *d) : MDCacheContext(c), dn(d) {}
void finish(int r) {
mdcache->eval_stray(dn);
}
};
void MDCache::eval_stray(CDentry *dn, bool delay)
/**
* If a remote dentry refers to an inode whose primary
* dentry is a stray, then evaluate the inode for purging if
* we have the auth copy, or migrate the stray to use if we
* do not.
*/
void MDCache::eval_remote(CDentry *remote_dn)
{
dout(10) << "eval_stray " << *dn << dendl;
CDentry::linkage_t *dnl = dn->get_projected_linkage();
dout(10) << " inode is " << *dnl->get_inode() << dendl;
assert(dnl->is_primary());
CInode *in = dnl->get_inode();
assert(in);
assert(remote_dn);
dout(10) << "eval_remote " << *remote_dn << dendl;
assert(dn->get_dir()->get_inode()->is_stray());
if (!dn->is_auth()) {
// has to be mine
// move to bottom of lru so that we trim quickly!
touch_dentry_bottom(dn);
return;
}
// purge?
if (in->inode.nlink == 0) {
// past snaprealm parents imply snapped dentry remote links.
// only important for directories. normal file data snaps are handled
// by the object store.
if (in->snaprealm && in->snaprealm->has_past_parents()) {
if (!in->snaprealm->have_past_parents_open() &&
!in->snaprealm->open_parents(new C_MDC_EvalStray(this, dn)))
return;
in->snaprealm->prune_past_parents();
in->purge_stale_snap_data(in->snaprealm->get_snaps());
}
if (in->is_dir()) {
if (in->snaprealm && in->snaprealm->has_past_parents()) {
dout(20) << " directory has past parents " << in->snaprealm->srnode.past_parents << dendl;
return; // not until some snaps are deleted.
}
if (in->has_dirfrags()) {
list<CDir*> ls;
in->get_nested_dirfrags(ls);
for (list<CDir*>::iterator p = ls.begin(); p != ls.end(); ++p)
(*p)->try_remove_dentries_for_stray();
}
}
if (dn->is_replicated()) {
dout(20) << " replicated" << dendl;
return;
}
if (dn->is_any_leases() || in->is_any_caps()) {
dout(20) << " caps | leases" << dendl;
return; // wait
}
if (dn->state_test(CDentry::STATE_PURGING)) {
dout(20) << " already purging" << dendl;
return; // already purging
}
if (in->state_test(CInode::STATE_NEEDSRECOVER) ||
in->state_test(CInode::STATE_RECOVERING)) {
dout(20) << " pending recovery" << dendl;
return; // don't mess with file size probing
}
if (in->get_num_ref() > (int)in->is_dirty() + (int)in->is_dirty_parent()) {
dout(20) << " too many inode refs" << dendl;
return;
}
if (dn->get_num_ref() > (int)dn->is_dirty() + !!in->get_num_ref()) {
dout(20) << " too many dn refs" << dendl;
return;
}
if (delay) {
if (!dn->item_stray.is_on_list()) {
delayed_eval_stray.push_back(&dn->item_stray);
num_strays_delayed++;
logger->set(l_mdc_num_strays_delayed, num_strays_delayed);
}
// don't purge multiversion inode with snap data
} else if (in->snaprealm && in->snaprealm->has_past_parents() &&
!in->old_inodes.empty()) {
assert(!in->is_dir());
dout(20) << " file has past parents " << in->snaprealm->srnode.past_parents << dendl;
if (in->is_file() && in->get_projected_inode()->size > 0)
truncate_stray(dn); // truncate head objects
} else {
if (in->is_dir())
in->close_dirfrags();
purge_stray(dn);
}
}
else if (in->inode.nlink >= 1) {
// trivial reintegrate?
if (!in->remote_parents.empty()) {
CDentry *rlink = *in->remote_parents.begin();
// don't do anything if the remote parent is projected, or we may
// break user-visible semantics!
// NOTE: we repeat this check in _rename(), since our submission path is racey.
if (!rlink->is_projected()) {
if (rlink->is_auth() && rlink->dir->can_auth_pin())
reintegrate_stray(dn, rlink);
if (!rlink->is_auth() && dn->is_auth())
migrate_stray(dn, rlink->authority().first);
}
}
} else {
// wait for next use.
}
}
void MDCache::eval_remote(CDentry *dn)
{
dout(10) << "eval_remote " << *dn << dendl;
CDentry::linkage_t *dnl = dn->get_projected_linkage();
CDentry::linkage_t *dnl = remote_dn->get_projected_linkage();
assert(dnl->is_remote());
CInode *in = dnl->get_inode();
if (!in) return;
if (!in) {
dout(20) << __func__ << ": no inode, cannot evaluate" << dendl;
return;
}
// refers to stray?
if (in->get_parent_dn()->get_dir()->get_inode()->is_stray()) {
if (in->is_auth())
eval_stray(in->get_parent_dn());
else
migrate_stray(in->get_parent_dn(), mds->get_nodeid());
CDentry *stray_dn = in->get_parent_dn();
if (in->is_auth()) {
dout(20) << __func__ << ": have auth for inode, evaluating" << dendl;
stray_manager.eval_remote_stray(stray_dn, remote_dn);
} else {
dout(20) << __func__ << ": do not have auth for inode, migrating " << dendl;
/*
* Inodes get filed into a stray dentry when a client unlinks
* the primary DN for them. However, that doesn't mean there
* isn't a remote DN still in the world. The remote DN just
* ends up pointing at a stray. Strays can pretty much live
* forever in this scenario.
*
* Therefore, we have a special behaviour here: migrate a stray
* to <me> when <I> handle a client request with a trace referring
* to a stray inode on another MDS.
*/
stray_manager.migrate_stray(stray_dn, mds->get_nodeid());
}
} else {
dout(20) << __func__ << ": inode's primary dn not stray" << dendl;
}
}
@ -9231,346 +9156,6 @@ void MDCache::fetch_backtrace(inodeno_t ino, int64_t pool, bufferlist& bl, Conte
mds->objecter->getxattr(oid, object_locator_t(pool), "parent", CEPH_NOSNAP, &bl, 0, fin);
}
class C_IO_MDC_PurgeStrayPurged : public MDCacheIOContext {
CDentry *dn;
bool only_head;
public:
C_IO_MDC_PurgeStrayPurged(MDCache *c, CDentry *d, bool oh) :
MDCacheIOContext(c), dn(d), only_head(oh) { }
void finish(int r) {
assert(r == 0 || r == -ENOENT);
mdcache->_purge_stray_purged(dn, only_head);
}
};
void MDCache::truncate_stray(CDentry *dn)
{
CDentry::linkage_t *dnl = dn->get_projected_linkage();
CInode *in = dnl->get_inode();
dout(10) << "truncate_stray " << *dn << " " << *in << dendl;
assert(!dn->is_replicated());
dn->state_set(CDentry::STATE_PURGING);
dn->get(CDentry::PIN_PURGING);
in->state_set(CInode::STATE_PURGING);
if (dn->item_stray.is_on_list())
dn->item_stray.remove_myself();
C_GatherBuilder gather(
g_ceph_context,
new C_OnFinisher(new C_IO_MDC_PurgeStrayPurged(this, dn, true),
&mds->finisher));
SnapRealm *realm = in->find_snaprealm();
assert(realm);
dout(10) << " realm " << *realm << dendl;
const SnapContext *snapc = &realm->get_snap_context();
uint64_t period = (uint64_t)in->inode.layout.fl_object_size *
(uint64_t)in->inode.layout.fl_stripe_count;
uint64_t to = in->inode.get_max_size();
to = MAX(in->inode.size, to);
// when truncating a file, the filer does not delete stripe objects that are
// truncated to zero. so we need to purge stripe objects up to the max size
// the file has ever been.
to = MAX(in->inode.max_size_ever, to);
if (period && to > period) {
uint64_t num = (to - 1) / period;
dout(10) << "purge_stray 0~" << to << " objects 0~" << num
<< " snapc " << snapc << " on " << *in << dendl;
mds->filer->purge_range(in->ino(), &in->inode.layout, *snapc,
1, num, ceph_clock_now(g_ceph_context),
0, gather.new_sub());
}
// keep backtrace object
if (period && to > 0) {
mds->filer->zero(in->ino(), &in->inode.layout, *snapc,
0, period, ceph_clock_now(g_ceph_context),
0, true, NULL, gather.new_sub());
}
assert(gather.has_subs());
gather.activate();
}
void MDCache::purge_stray(CDentry *dn)
{
CDentry::linkage_t *dnl = dn->get_projected_linkage();
CInode *in = dnl->get_inode();
dout(10) << "purge_stray " << *dn << " " << *in << dendl;
assert(!dn->is_replicated());
dn->state_set(CDentry::STATE_PURGING);
dn->get(CDentry::PIN_PURGING);
in->state_set(CInode::STATE_PURGING);
num_strays_purging++;
logger->set(l_mdc_num_strays_purging, num_strays_purging);
if (dn->item_stray.is_on_list()) {
dn->item_stray.remove_myself();
num_strays_delayed--;
logger->set(l_mdc_num_strays_delayed, num_strays_delayed);
}
if (in->is_dirty_parent())
in->clear_dirty_parent();
// CHEAT. there's no real need to journal our intent to purge, since
// that is implicit in the dentry's presence and non-use in the stray
// dir. on recovery, we'll need to re-eval all strays anyway.
SnapContext nullsnapc;
C_GatherBuilder gather(
g_ceph_context,
new C_OnFinisher(new C_IO_MDC_PurgeStrayPurged(this, dn, false),
&mds->finisher));
if (in->is_dir()) {
object_locator_t oloc(mds->mdsmap->get_metadata_pool());
list<frag_t> ls;
if (!in->dirfragtree.is_leaf(frag_t()))
in->dirfragtree.get_leaves(ls);
ls.push_back(frag_t());
for (list<frag_t>::iterator p = ls.begin();
p != ls.end();
++p) {
object_t oid = CInode::get_object_name(in->inode.ino, *p, "");
dout(10) << "purge_stray remove dirfrag " << oid << dendl;
mds->objecter->remove(oid, oloc, nullsnapc, ceph_clock_now(g_ceph_context),
0, NULL, gather.new_sub());
}
assert(gather.has_subs());
gather.activate();
return;
}
const SnapContext *snapc;
SnapRealm *realm = in->find_snaprealm();
if (realm) {
dout(10) << " realm " << *realm << dendl;
snapc = &realm->get_snap_context();
} else {
dout(10) << " NO realm, using null context" << dendl;
snapc = &nullsnapc;
assert(in->last == CEPH_NOSNAP);
}
if (in->is_file()) {
uint64_t period = (uint64_t)in->inode.layout.fl_object_size *
(uint64_t)in->inode.layout.fl_stripe_count;
uint64_t to = in->inode.get_max_size();
to = MAX(in->inode.size, to);
// when truncating a file, the filer does not delete stripe objects that are
// truncated to zero. so we need to purge stripe objects up to the max size
// the file has ever been.
to = MAX(in->inode.max_size_ever, to);
if (to && period) {
uint64_t num = (to + period - 1) / period;
dout(10) << "purge_stray 0~" << to << " objects 0~" << num
<< " snapc " << snapc << " on " << *in << dendl;
mds->filer->purge_range(in->inode.ino, &in->inode.layout, *snapc,
0, num, ceph_clock_now(g_ceph_context), 0,
gather.new_sub());
}
}
inode_t *pi = in->get_projected_inode();
object_t oid = CInode::get_object_name(pi->ino, frag_t(), "");
// remove the backtrace object if it was not purged
if (!gather.has_subs()) {
object_locator_t oloc(pi->layout.fl_pg_pool);
dout(10) << "purge_stray remove backtrace object " << oid
<< " pool " << oloc.pool << " snapc " << snapc << dendl;
mds->objecter->remove(oid, oloc, *snapc, ceph_clock_now(g_ceph_context), 0,
NULL, gather.new_sub());
}
// remove old backtrace objects
for (compact_set<int64_t>::iterator p = pi->old_pools.begin();
p != pi->old_pools.end();
++p) {
object_locator_t oloc(*p);
dout(10) << "purge_stray remove backtrace object " << oid
<< " old pool " << *p << " snapc " << snapc << dendl;
mds->objecter->remove(oid, oloc, *snapc, ceph_clock_now(g_ceph_context), 0,
NULL, gather.new_sub());
}
assert(gather.has_subs());
gather.activate();
}
class C_MDC_PurgeStrayLogged : public MDCacheContext {
CDentry *dn;
version_t pdv;
LogSegment *ls;
public:
C_MDC_PurgeStrayLogged(MDCache *c, CDentry *d, version_t v, LogSegment *s) :
MDCacheContext(c), dn(d), pdv(v), ls(s) { }
void finish(int r) {
mdcache->_purge_stray_logged(dn, pdv, ls);
}
};
class C_MDC_PurgeStrayLoggedTruncate : public MDCacheContext {
CDentry *dn;
LogSegment *ls;
public:
C_MDC_PurgeStrayLoggedTruncate(MDCache *c, CDentry *d, LogSegment *s) :
MDCacheContext(c), dn(d), ls(s) { }
void finish(int r) {
mdcache->_purge_stray_logged_truncate(dn, ls);
}
};
void MDCache::_purge_stray_purged(CDentry *dn, bool only_head)
{
CInode *in = dn->get_projected_linkage()->get_inode();
dout(10) << "_purge_stray_purged " << *dn << " " << *in << dendl;
if (!only_head &&
in->get_num_ref() == (int)in->is_dirty() &&
dn->get_num_ref() == (int)dn->is_dirty() + !!in->get_num_ref() + 1/*PIN_PURGING*/) {
// kill dentry.
version_t pdv = dn->pre_dirty();
dn->push_projected_linkage(); // NULL
EUpdate *le = new EUpdate(mds->mdlog, "purge_stray");
mds->mdlog->start_entry(le);
// update dirfrag fragstat, rstat
CDir *dir = dn->get_dir();
fnode_t *pf = dir->project_fnode();
pf->version = dir->pre_dirty();
if (in->is_dir())
pf->fragstat.nsubdirs--;
else
pf->fragstat.nfiles--;
pf->rstat.sub(in->inode.accounted_rstat);
le->metablob.add_dir_context(dn->dir);
EMetaBlob::dirlump& dl = le->metablob.add_dir(dn->dir, true);
le->metablob.add_null_dentry(dl, dn, true);
le->metablob.add_destroyed_inode(in->ino());
mds->mdlog->submit_entry(le, new C_MDC_PurgeStrayLogged(this, dn, pdv, mds->mdlog->get_current_segment()));
num_strays_purging--;
num_strays--;
logger->set(l_mdc_num_strays, num_strays);
logger->set(l_mdc_num_strays_purging, num_strays_purging);
logger->inc(l_mdc_strays_purged);
} else {
// new refs.. just truncate to 0
EUpdate *le = new EUpdate(mds->mdlog, "purge_stray truncate");
mds->mdlog->start_entry(le);
inode_t *pi = in->project_inode();
pi->size = 0;
pi->max_size_ever = 0;
pi->client_ranges.clear();
pi->truncate_size = 0;
pi->truncate_from = 0;
pi->version = in->pre_dirty();
le->metablob.add_dir_context(dn->dir);
le->metablob.add_primary_dentry(dn, in, true);
mds->mdlog->submit_entry(le, new C_MDC_PurgeStrayLoggedTruncate(this, dn, mds->mdlog->get_current_segment()));
}
}
void MDCache::_purge_stray_logged(CDentry *dn, version_t pdv, LogSegment *ls)
{
CInode *in = dn->get_linkage()->get_inode();
dout(10) << "_purge_stray_logged " << *dn << " " << *in << dendl;
assert(!in->state_test(CInode::STATE_RECOVERING));
// unlink
assert(dn->get_projected_linkage()->is_null());
dn->dir->unlink_inode(dn);
dn->pop_projected_linkage();
dn->mark_dirty(pdv, ls);
dn->dir->pop_and_dirty_projected_fnode(ls);
in->state_clear(CInode::STATE_ORPHAN);
dn->state_clear(CDentry::STATE_PURGING);
dn->put(CDentry::PIN_PURGING);
// drop inode
if (in->is_dirty())
in->mark_clean();
remove_inode(in);
// drop dentry?
if (dn->is_new()) {
dout(20) << " dn is new, removing" << dendl;
dn->mark_clean();
dn->dir->remove_dentry(dn);
} else
touch_dentry_bottom(dn); // drop dn as quickly as possible.
}
void MDCache::_purge_stray_logged_truncate(CDentry *dn, LogSegment *ls)
{
CInode *in = dn->get_projected_linkage()->get_inode();
dout(10) << "_purge_stray_logged_truncate " << *dn << " " << *in << dendl;
dn->state_clear(CDentry::STATE_PURGING);
dn->put(CDentry::PIN_PURGING);
in->pop_and_dirty_projected_inode(ls);
eval_stray(dn);
}
void MDCache::reintegrate_stray(CDentry *straydn, CDentry *rdn)
{
dout(10) << "reintegrate_stray " << *straydn << " into " << *rdn << dendl;
// rename it to another mds.
filepath src;
straydn->make_path(src);
filepath dst;
rdn->make_path(dst);
MClientRequest *req = new MClientRequest(CEPH_MDS_OP_RENAME);
req->set_filepath(dst);
req->set_filepath2(src);
req->set_tid(mds->issue_tid());
mds->send_message_mds(req, rdn->authority().first);
}
void MDCache::migrate_stray(CDentry *dn, mds_rank_t to)
{
CInode *in = dn->get_linkage()->get_inode();
assert(in);
CInode *diri = dn->dir->get_inode();
assert(diri->is_stray());
dout(10) << "migrate_stray from mds." << MDS_INO_STRAY_OWNER(diri->inode.ino)
<< " to mds." << to
<< " " << *dn << " " << *in << dendl;
// rename it to another mds.
filepath src;
dn->make_path(src);
string dname;
in->name_stray_dentry(dname);
filepath dst(dname, MDS_INO_STRAY(to, 0));
MClientRequest *req = new MClientRequest(CEPH_MDS_OP_RENAME);
req->set_filepath(dst);
req->set_filepath2(src);
req->set_tid(mds->issue_tid());
mds->send_message_mds(req, to);
}
@ -12068,9 +11653,12 @@ void MDCache::register_perfcounters()
"Stray dentries", "stry");
pcb.add_u64(l_mdc_num_strays_purging, "num_strays_purging");
pcb.add_u64(l_mdc_num_strays_delayed, "num_strays_delayed");
pcb.add_u64(l_mdc_num_purge_ops, "num_purge_ops");
pcb.add_u64_counter(l_mdc_strays_created, "strays_created");
pcb.add_u64_counter(l_mdc_strays_purged, "strays_purged",
"Stray dentries purged", "purg");
pcb.add_u64_counter(l_mdc_strays_reintegrated, "strays_reintegrated");
pcb.add_u64_counter(l_mdc_strays_migrated, "strays_migrated");
/* Recovery queue statistics */
pcb.add_u64(l_mdc_num_recovering_processing, "num_recovering_processing");
@ -12084,5 +11672,37 @@ void MDCache::register_perfcounters()
logger = pcb.create_perf_counters();
g_ceph_context->get_perfcounters_collection()->add(logger);
recovery_queue.set_logger(logger);
stray_manager.set_logger(logger);
}
/**
* Call this when putting references to an inode/dentry or
* when attempting to trim it.
*
* If this inode is no longer linked by anyone, and this MDS
* rank holds the primary dentry, and that dentry is in a stray
* directory, then give up the dentry to the StrayManager, never
* to be seen again by MDCache.
*
* @param delay if true, then purgeable inodes are stashed til
* the next trim(), rather than being purged right
* away.
*/
void MDCache::maybe_eval_stray(CInode *in, bool delay) {
if (in->inode.nlink > 0 || in->is_base() || is_readonly() || mds->is_standby_replay())
return;
CDentry *dn = in->get_projected_parent_dn();
if (dn->state_test(CDentry::STATE_PURGING)) {
/* We have already entered the purging process, no need
* to re-evaluate me ! */
return;
}
if (dn->get_projected_linkage()->is_primary() &&
dn->get_dir()->get_inode()->is_stray()) {
stray_manager.eval_stray(dn, delay);
}
}

63
src/mds/MDCache.h
View File

@ -27,6 +27,7 @@
#include "include/Context.h"
#include "events/EMetaBlob.h"
#include "RecoveryQueue.h"
#include "StrayManager.h"
#include "MDSContext.h"
#include "messages/MClientRequest.h"
@ -74,16 +75,22 @@ struct MDSlaveUpdate;
enum {
l_mdc_first = 3000,
// How many dentries are currently in stray dirs
// How many inodes currently in stray dentries
l_mdc_num_strays,
// How many stray dentries are currently being purged
l_mdc_num_strays_purging,
// How many stray dentries are currently delayed for purge due to refs
l_mdc_num_strays_delayed,
// How many purge RADOS ops might currently be in flight?
l_mdc_num_purge_ops,
// How many dentries have ever been added to stray dir
l_mdc_strays_created,
// How many dentries have ever finished purging from stray dir
l_mdc_strays_purged,
// How many strays have been reintegrated?
l_mdc_strays_reintegrated,
// How many strays have been migrated?
l_mdc_strays_migrated,
// How many inode sizes currently being recovered
l_mdc_num_recovering_processing,
@ -135,6 +142,17 @@ public:
void advance_stray() {
stray_index = (stray_index+1)%NUM_STRAY;
}
/**
* Call this when you know that a CDentry is ready to be passed
* on to StrayManager (i.e. this is a stray you've just created)
*/
void notify_stray(CDentry *dn) {
assert(dn->get_dir()->get_inode()->is_stray());
stray_manager.eval_stray(dn);
}
void maybe_eval_stray(CInode *in, bool delay=false);
bool is_readonly() { return readonly; }
void force_readonly();
@ -143,10 +161,6 @@ public:
int num_inodes_with_caps;
int num_caps;
uint64_t num_strays;
uint64_t num_strays_purging;
uint64_t num_strays_delayed;
unsigned max_dir_commit_size;
ceph_file_layout default_file_layout;
@ -166,6 +180,16 @@ public:
r->ttl = ttl;
}
void notify_stray_removed()
{
stray_manager.notify_stray_removed();
}
void notify_stray_created()
{
stray_manager.notify_stray_created();
}
// -- client caps --
uint64_t last_cap_id;
@ -569,6 +593,9 @@ public:
friend class Migrator;
friend class MDBalancer;
// StrayManager needs to be able to remove_inode() from us
// when it is done purging
friend class StrayManager;
// File size recovery
private:
@ -913,38 +940,14 @@ public:
// -- stray --
public:
elist<CDentry*> delayed_eval_stray;
void eval_stray(CDentry *dn, bool delay=false);
void eval_remote(CDentry *dn);
void maybe_eval_stray(CInode *in, bool delay=false) {
if (in->inode.nlink > 0 || in->is_base() || is_readonly())
return;
CDentry *dn = in->get_projected_parent_dn();
if (!dn->state_test(CDentry::STATE_PURGING) &&
dn->get_projected_linkage()->is_primary() &&
dn->get_dir()->get_inode()->is_stray())
eval_stray(dn, delay);
}
void fetch_backtrace(inodeno_t ino, int64_t pool, bufferlist& bl, Context *fin);
protected:
void scan_stray_dir(dirfrag_t next=dirfrag_t());
void truncate_stray(CDentry *dn);
void purge_stray(CDentry *dn);
void _purge_stray_purged(CDentry *dn, bool only_head);
void _purge_stray_logged(CDentry *dn, version_t pdv, LogSegment *ls);
void _purge_stray_logged_truncate(CDentry *dn, LogSegment *ls);
StrayManager stray_manager;
friend struct C_MDC_RetryScanStray;
friend class C_IO_MDC_FetchedBacktrace;
friend class C_MDC_PurgeStrayLogged;
friend class C_MDC_PurgeStrayLoggedTruncate;
friend class C_IO_MDC_PurgeStrayPurged;
void reintegrate_stray(CDentry *dn, CDentry *rlink);
void migrate_stray(CDentry *dn, mds_rank_t dest);
// == messages ==
public:

2
src/mds/Makefile.am
View File

@ -11,6 +11,7 @@ libmds_la_SOURCES = \
mds/Mutation.cc \
mds/MDCache.cc \
mds/RecoveryQueue.cc \
mds/StrayManager.cc \
mds/Locker.cc \
mds/Migrator.cc \
mds/MDBalancer.cc \
@ -53,6 +54,7 @@ noinst_HEADERS += \
mds/MDBalancer.h \
mds/MDCache.h \
mds/RecoveryQueue.h \
mds/StrayManager.h \
mds/MDLog.h \
mds/MDS.h \
mds/Beacon.h \

26
src/mds/Server.cc
View File

@ -5348,8 +5348,11 @@ void Server::_unlink_local_finish(MDRequestRef& mdr,
dn->get_dir()->try_remove_unlinked_dn(dn);
// clean up?
if (straydn)
mdcache->eval_stray(straydn);
if (straydn) {
// Tip off the MDCache that this dentry is a stray that
// might be elegible for purge.
mdcache->notify_stray(straydn);
}
}
bool Server::_rmdir_prepare_witness(MDRequestRef& mdr, mds_rank_t who, CDentry *dn, CDentry *straydn)
@ -6183,8 +6186,9 @@ void Server::_rename_finish(MDRequestRef& mdr, CDentry *srcdn, CDentry *destdn,
mds->locker->eval(in, CEPH_CAP_LOCKS, true);
// clean up?
if (straydn)
mdcache->eval_stray(straydn);
if (straydn) {
mdcache->notify_stray(straydn);
}
}
@ -6694,6 +6698,20 @@ void Server::_rename_apply(MDRequestRef& mdr, CDentry *srcdn, CDentry *destdn, C
}
}
if (srcdn->get_dir()->inode->is_stray() &&
srcdn->get_dir()->inode->get_stray_owner() == mds->whoami) {
// A reintegration event or a migration away from me
dout(20) << __func__ << ": src dentry was a stray, updating stats" << dendl;
mdcache->notify_stray_removed();
}
if (destdn->get_dir()->inode->is_stray() &&
destdn->get_dir()->inode->get_stray_owner() == mds->whoami) {
// A stray migration (to me)
dout(20) << __func__ << ": dst dentry was a stray, updating stats" << dendl;
mdcache->notify_stray_created();
}
// src
if (srcdn->is_auth())
srcdn->mark_dirty(mdr->more()->pvmap[srcdn], mdr->ls);

911
src/mds/StrayManager.cc Normal file
View File

@ -0,0 +1,911 @@
// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab
/*
* Ceph - scalable distributed file system
*
* Copyright (C) 2015 Red Hat
*
* This is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 2.1, as published by the Free Software
* Foundation. See file COPYING.
*
*/
#include "common/perf_counters.h"
#include "osdc/Objecter.h"
#include "osdc/Filer.h"
#include "mds/MDS.h"
#include "mds/MDCache.h"
#include "mds/MDLog.h"
#include "mds/CDir.h"
#include "mds/CDentry.h"
#include "events/EUpdate.h"
#include "messages/MClientRequest.h"
#include "StrayManager.h"
#define dout_subsys ceph_subsys_mds
#undef dout_prefix
#define dout_prefix _prefix(_dout, mds)
static ostream& _prefix(std::ostream *_dout, MDS *mds) {
return *_dout << "mds." << mds->get_nodeid() << ".cache.strays ";
}
class StrayManagerIOContext : public virtual MDSIOContextBase {
protected:
StrayManager *sm;
virtual MDS *get_mds()
{
return sm->mds;
}
public:
StrayManagerIOContext(StrayManager *sm_) : sm(sm_) {}
};
class StrayManagerContext : public virtual MDSInternalContextBase {
protected:
StrayManager *sm;
virtual MDS *get_mds()
{
return sm->mds;
}
public:
StrayManagerContext(StrayManager *sm_) : sm(sm_) {}
};
/**
* Context wrapper for _purge_stray_purged completion
*/
class C_IO_PurgeStrayPurged : public StrayManagerIOContext {
CDentry *dn;
bool only_head;
// How many ops_in_flight were allocated to this purge?
uint32_t ops_allowance;
public:
C_IO_PurgeStrayPurged(StrayManager *sm_, CDentry *d, bool oh, uint32_t ops) :
StrayManagerIOContext(sm_), dn(d), only_head(oh), ops_allowance(ops) { }
void finish(int r) {
assert(r == 0 || r == -ENOENT);
sm->_purge_stray_purged(dn, ops_allowance, only_head);
}
};
/**
* Purge a dentry from a stray directory. This function
* is called once eval_stray is satisfied and StrayManager
* throttling is also satisfied. There is no going back
* at this stage!
*/
void StrayManager::purge(CDentry *dn, uint32_t op_allowance)
{
CDentry::linkage_t *dnl = dn->get_projected_linkage();
CInode *in = dnl->get_inode();
dout(10) << __func__ << " " << *dn << " " << *in << dendl;
assert(!dn->is_replicated());
num_strays_purging++;
logger->set(l_mdc_num_strays_purging, num_strays_purging);
if (dn->item_stray.is_on_list()) {
dn->item_stray.remove_myself();
num_strays_delayed--;
logger->set(l_mdc_num_strays_delayed, num_strays_delayed);
}
// CHEAT. there's no real need to journal our intent to purge, since
// that is implicit in the dentry's presence and non-use in the stray
// dir. on recovery, we'll need to re-eval all strays anyway.
SnapContext nullsnapc;
C_GatherBuilder gather(
g_ceph_context,
new C_OnFinisher(new C_IO_PurgeStrayPurged(
this, dn, false, op_allowance), &mds->finisher));
if (in->is_dir()) {
object_locator_t oloc(mds->mdsmap->get_metadata_pool());
std::list<frag_t> ls;
if (!in->dirfragtree.is_leaf(frag_t()))
in->dirfragtree.get_leaves(ls);
ls.push_back(frag_t());
for (std::list<frag_t>::iterator p = ls.begin();
p != ls.end();
++p) {
object_t oid = CInode::get_object_name(in->inode.ino, *p, "");
dout(10) << __func__ << " remove dirfrag " << oid << dendl;
mds->objecter->remove(oid, oloc, nullsnapc, ceph_clock_now(g_ceph_context),
0, NULL, gather.new_sub());
}
assert(gather.has_subs());
gather.activate();
return;
}
const SnapContext *snapc;
SnapRealm *realm = in->find_snaprealm();
if (realm) {
dout(10) << " realm " << *realm << dendl;
snapc = &realm->get_snap_context();
} else {
dout(10) << " NO realm, using null context" << dendl;
snapc = &nullsnapc;
assert(in->last == CEPH_NOSNAP);
}
if (in->is_file()) {
uint64_t period = (uint64_t)in->inode.layout.fl_object_size *
(uint64_t)in->inode.layout.fl_stripe_count;
uint64_t to = in->inode.get_max_size();
to = MAX(in->inode.size, to);
// when truncating a file, the filer does not delete stripe objects that are
// truncated to zero. so we need to purge stripe objects up to the max size
// the file has ever been.
to = MAX(in->inode.max_size_ever, to);
if (to && period) {
uint64_t num = (to + period - 1) / period;
dout(10) << __func__ << " 0~" << to << " objects 0~" << num
<< " snapc " << snapc << " on " << *in << dendl;
mds->filer->purge_range(in->inode.ino, &in->inode.layout, *snapc,
0, num, ceph_clock_now(g_ceph_context), 0,
gather.new_sub());
}
}
inode_t *pi = in->get_projected_inode();
object_t oid = CInode::get_object_name(pi->ino, frag_t(), "");
// remove the backtrace object if it was not purged
if (!gather.has_subs()) {
object_locator_t oloc(pi->layout.fl_pg_pool);
dout(10) << __func__ << " remove backtrace object " << oid
<< " pool " << oloc.pool << " snapc " << snapc << dendl;
mds->objecter->remove(oid, oloc, *snapc, ceph_clock_now(g_ceph_context), 0,
NULL, gather.new_sub());
}
// remove old backtrace objects
for (compact_set<int64_t>::iterator p = pi->old_pools.begin();
p != pi->old_pools.end();
++p) {
object_locator_t oloc(*p);
dout(10) << __func__ << " remove backtrace object " << oid
<< " old pool " << *p << " snapc " << snapc << dendl;
mds->objecter->remove(oid, oloc, *snapc, ceph_clock_now(g_ceph_context), 0,
NULL, gather.new_sub());
}
assert(gather.has_subs());
gather.activate();
}
class C_PurgeStrayLogged : public StrayManagerContext {
CDentry *dn;
version_t pdv;
LogSegment *ls;
public:
C_PurgeStrayLogged(StrayManager *sm_, CDentry *d, version_t v, LogSegment *s) :
StrayManagerContext(sm_), dn(d), pdv(v), ls(s) { }
void finish(int r) {
sm->_purge_stray_logged(dn, pdv, ls);
}
};
class C_TruncateStrayLogged : public StrayManagerContext {
CDentry *dn;
LogSegment *ls;
public:
C_TruncateStrayLogged(StrayManager *sm, CDentry *d, LogSegment *s) :
StrayManagerContext(sm), dn(d), ls(s) { }
void finish(int r) {
sm->_truncate_stray_logged(dn, ls);
}
};
/**
* Completion handler for a Filer::purge on a stray inode.
*
*
*/
void StrayManager::_purge_stray_purged(
CDentry *dn, uint32_t ops_allowance, bool only_head)
{
CInode *in = dn->get_projected_linkage()->get_inode();
dout(10) << "_purge_stray_purged " << *dn << " " << *in << dendl;
if (only_head) {
/* This was a ::truncate */
EUpdate *le = new EUpdate(mds->mdlog, "purge_stray truncate");
mds->mdlog->start_entry(le);
inode_t *pi = in->project_inode();
pi->size = 0;
pi->max_size_ever = 0;
pi->client_ranges.clear();
pi->truncate_size = 0;
pi->truncate_from = 0;
pi->version = in->pre_dirty();
le->metablob.add_dir_context(dn->dir);
le->metablob.add_primary_dentry(dn, in, true);
mds->mdlog->submit_entry(le,
new C_TruncateStrayLogged(
this, dn, mds->mdlog->get_current_segment()));
} else {
if (in->get_num_ref() != (int)in->is_dirty() ||
dn->get_num_ref() != (int)dn->is_dirty() + !!in->get_num_ref() + 1/*PIN_PURGING*/) {
// Nobody should be taking new references to an inode when it
// is being purged (aside from it it were
derr << "Rogue reference after purge to " << *dn << dendl;
assert(0 == "rogue reference to purging inode");
}
// kill dentry.
version_t pdv = dn->pre_dirty();
dn->push_projected_linkage(); // NULL
EUpdate *le = new EUpdate(mds->mdlog, "purge_stray");
mds->mdlog->start_entry(le);
// update dirfrag fragstat, rstat
CDir *dir = dn->get_dir();
fnode_t *pf = dir->project_fnode();
pf->version = dir->pre_dirty();
if (in->is_dir())
pf->fragstat.nsubdirs--;
else
pf->fragstat.nfiles--;
pf->rstat.sub(in->inode.accounted_rstat);
le->metablob.add_dir_context(dn->dir);
EMetaBlob::dirlump& dl = le->metablob.add_dir(dn->dir, true);
le->metablob.add_null_dentry(dl, dn, true);
le->metablob.add_destroyed_inode(in->ino());
mds->mdlog->submit_entry(le, new C_PurgeStrayLogged(this, dn, pdv,
mds->mdlog->get_current_segment()));
num_strays--;
logger->set(l_mdc_num_strays, num_strays);
logger->inc(l_mdc_strays_purged);
}
num_strays_purging--;
logger->set(l_mdc_num_strays_purging, num_strays_purging);
// Release resources
dout(10) << __func__ << ": decrementing op allowance "
<< ops_allowance << " from " << ops_in_flight << " in flight" << dendl;
assert(ops_in_flight >= ops_allowance);
ops_in_flight -= ops_allowance;
logger->set(l_mdc_num_purge_ops, ops_in_flight);
files_purging -= 1;
_advance();
}
void StrayManager::_purge_stray_logged(CDentry *dn, version_t pdv, LogSegment *ls)
{
CInode *in = dn->get_linkage()->get_inode();
dout(10) << "_purge_stray_logged " << *dn << " " << *in << dendl;
assert(!in->state_test(CInode::STATE_RECOVERING));
// unlink
assert(dn->get_projected_linkage()->is_null());
dn->dir->unlink_inode(dn);
dn->pop_projected_linkage();
dn->mark_dirty(pdv, ls);
dn->dir->pop_and_dirty_projected_fnode(ls);
in->state_clear(CInode::STATE_ORPHAN);
dn->state_clear(CDentry::STATE_PURGING);
dn->put(CDentry::PIN_PURGING);
// drop inode
if (in->is_dirty())
in->mark_clean();
// drop dentry?
if (dn->is_new()) {
dout(20) << " dn is new, removing" << dendl;
dn->mark_clean();
dn->dir->remove_dentry(dn);
in->mdcache->remove_inode(in);
} else {
in->mdcache->touch_dentry_bottom(dn); // drop dn as quickly as possible.
}
}
/**
* Enqueue a purge operation on a dentry that has passed the tests
* in eval_stray. This may start the operation inline if the throttle
* allowances are already available.
*
* @param trunc false to purge dentry (normal), true to just truncate
* inode (snapshots)
*/
void StrayManager::enqueue(CDentry *dn, bool trunc)
{
CDentry::linkage_t *dnl = dn->get_projected_linkage();
assert(dnl);
CInode *in = dnl->get_inode();
assert(in);
/* We consider a stray to be purging as soon as it is enqueued, to avoid
* enqueing it twice */
dn->state_set(CDentry::STATE_PURGING);
dn->get(CDentry::PIN_PURGING);
in->state_set(CInode::STATE_PURGING);
/* We must clear this as soon as enqueuing it, to prevent the journal
* expiry code from seeing a dirty parent and trying to write a backtrace */
if (!trunc) {
if (in->is_dirty_parent()) {
in->clear_dirty_parent();
}
}
// Try to purge immediately if possible, else enqueue
const uint32_t ops_required = _calculate_ops_required(in, trunc);
bool consumed = _consume(dn, trunc, ops_required);
if (consumed) {
dout(10) << __func__ << ": purging this dentry immediately: "
<< *dn << dendl;
} else {
dout(10) << __func__ << ": enqueuing this dentry for later purge: "
<< *dn << dendl;
ready_for_purge.push_back(QueuedStray(dn, trunc, ops_required));
}
}
/**
* Iteratively call _consume on items from the ready_for_purge
* list until it returns false (throttle limit reached)
*/
void StrayManager::_advance()
{
std::list<QueuedStray>::iterator i;
for (i = ready_for_purge.begin();
i != ready_for_purge.end(); ++i) {
const QueuedStray &qs = *i;
const bool consumed = _consume(qs.dn, qs.trunc, qs.ops_required);
if (!consumed) {
break;
}
}
// Erase all the ones that returned true from _consume
ready_for_purge.erase(ready_for_purge.begin(), i);
}
/**
* Attempt to purge an inode, if throttling permits
* it. Note that there are compromises to how
* the throttling works, in interests of simplicity:
* * If insufficient ops are available to execute
* the next item on the queue, we block even if
* there are items further down the queue requiring
* fewer ops which might be executable
* * The ops considered "in use" by a purge will be
* an overestimate over the period of execution, as
* we count filer_max_purge_ops and ops for old backtraces
* as in use throughout, even though towards the end
* of the purge the actual ops in flight will be
* lower.
* * The ops limit may be exceeded if the number of ops
* required by a single inode is greater than the
* limit, for example directories with very many
* fragments.
*
* Return true if we successfully consumed resource,
* false if insufficient resource was available.
*/
bool StrayManager::_consume(CDentry *dn, bool trunc, uint32_t ops_required)
{
const int files_avail = g_conf->mds_max_purge_files - files_purging;
if (files_avail <= 0) {
dout(20) << __func__ << ": throttling on max files" << dendl;
return false;
} else {
dout(20) << __func__ << ": purging dn: " << *dn << dendl;
}
// Calculate how much of the ops allowance is available, allowing
// for the case where the limit is currently being exceeded.
uint32_t ops_avail;
if (ops_in_flight <= g_conf->mds_max_purge_ops) {
ops_avail = g_conf->mds_max_purge_ops - ops_in_flight;
} else {
ops_avail = 0;
}
/* The ops_in_flight > 0 condition here handles the case where the
* ops required by this inode would never fit in the limit: we wait
* instead until nothing else is running */
if (ops_in_flight > 0 && ops_avail < ops_required) {
dout(20) << __func__ << ": throttling on max ops (require "
<< ops_required << ", " << ops_in_flight << " in flight" << dendl;
return false;
}
// Resources are available, acquire them and execute the purge
files_purging += 1;
dout(10) << __func__ << ": allocating allowance "
<< ops_required << " to " << ops_in_flight << " in flight" << dendl;
ops_in_flight += ops_required;
logger->set(l_mdc_num_purge_ops, ops_in_flight);
if (trunc) {
truncate(dn, ops_required);
} else {
purge(dn, ops_required);
}
return true;
}
/**
* Return the maximum number of concurrent RADOS ops that
* may be executed while purging this inode.
*
* @param trunc true if it's a truncate, false if it's a purge
*/
uint32_t StrayManager::_calculate_ops_required(CInode *in, bool trunc)
{
uint32_t ops_required = 0;
if (in->is_dir()) {
// Directory, count dirfrags to be deleted
std::list<frag_t> ls;
if (!in->dirfragtree.is_leaf(frag_t())) {
in->dirfragtree.get_leaves(ls);
}
// One for the root, plus any leaves
ops_required = 1 + ls.size();
} else {
// File, work out concurrent Filer::purge deletes
const uint64_t period = (uint64_t)in->inode.layout.fl_object_size *
(uint64_t)in->inode.layout.fl_stripe_count;
const uint64_t to = MAX(in->inode.max_size_ever,
MAX(in->inode.size, in->inode.get_max_size()));
const uint64_t num = MAX(1, (to + period - 1) / period);
ops_required = MIN(num, g_conf->filer_max_purge_ops);
// Account for removing (or zeroing) backtrace
ops_required += 1;
// Account for deletions for old pools
if (!trunc) {
ops_required += in->get_projected_inode()->old_pools.size();
}
}
return ops_required;
}
void StrayManager::advance_delayed()
{
for (elist<CDentry*>::iterator p = delayed_eval_stray.begin(); !p.end(); ) {
CDentry *dn = *p;
++p;
dn->item_stray.remove_myself();
num_strays_delayed--;
if (dn->get_projected_linkage()->is_null()) {
/* A special case: a stray dentry can go null if its inode is being
* re-linked into another MDS's stray dir during a shutdown migration. */
dout(4) << __func__ << ": delayed dentry is now null: " << *dn << dendl;
continue;
}
const bool purging = eval_stray(dn);
if (!purging) {
derr << "Dentry " << *dn << " was purgeable but no longer is!" << dendl;
/*
* This can happen if a stray is purgeable, but has gained an extra
* reference by virtue of having its backtrace updated.
* FIXME perhaps we could simplify this further by
* avoiding writing the backtrace of purge-ready strays, so
* that this code could be more rigid?
*/
}
}
logger->set(l_mdc_num_strays_delayed, num_strays_delayed);
}
void StrayManager::notify_stray_created()
{
num_strays++;
logger->set(l_mdc_num_strays, num_strays);
logger->inc(l_mdc_strays_created);
}
void StrayManager::notify_stray_removed()
{
num_strays--;
logger->set(l_mdc_num_strays, num_strays);
}
struct C_EvalStray : public StrayManagerContext {
CDentry *dn;
C_EvalStray(StrayManager *sm_, CDentry *d) : StrayManagerContext(sm_), dn(d) {}
void finish(int r) {
sm->eval_stray(dn);
}
};
struct C_MDC_EvalStray : public StrayManagerContext {
CDentry *dn;
C_MDC_EvalStray(StrayManager *sm_, CDentry *d) : StrayManagerContext(sm_), dn(d) {}
void finish(int r) {
sm->eval_stray(dn);
}
};
/**
* Evaluate a stray dentry for purging or reintegration.
*
* If the inode has no linkage, and no more references, then
* we may decide to purge it.
*
* If the inode still has linkage, then it means someone else
* (a hard link) is still referring to it, and we should
* think about reintegrating that inode into the remote dentry.
*
* @returns true if the dentry will be purged (caller should never
* take more refs after this happens), else false.
*/
bool StrayManager::eval_stray(CDentry *dn, bool delay)
{
dout(10) << "eval_stray " << *dn << dendl;
CDentry::linkage_t *dnl = dn->get_projected_linkage();
assert(dnl->is_primary());
dout(10) << " inode is " << *dnl->get_inode() << dendl;
CInode *in = dnl->get_inode();
assert(in);
// The only dentries elegible for purging are those
// in the stray directories
assert(dn->get_dir()->get_inode()->is_stray());
// Inode may not pass through this function if it
// was already identified for purging (i.e. cannot
// call eval_stray() after purge()
assert(!dn->state_test(CDentry::STATE_PURGING));
if (!dn->is_auth()) {
// has to be mine
// move to bottom of lru so that we trim quickly!
in->mdcache->touch_dentry_bottom(dn);
return false;
}
// purge?
if (in->inode.nlink == 0) {
// past snaprealm parents imply snapped dentry remote links.
// only important for directories. normal file data snaps are handled
// by the object store.
if (in->snaprealm && in->snaprealm->has_past_parents()) {
if (!in->snaprealm->have_past_parents_open() &&
!in->snaprealm->open_parents(new C_MDC_EvalStray(this, dn))) {
return false;
}
in->snaprealm->prune_past_parents();
in->purge_stale_snap_data(in->snaprealm->get_snaps());
}
if (in->is_dir()) {
if (in->snaprealm && in->snaprealm->has_past_parents()) {
dout(20) << " directory has past parents "
<< in->snaprealm->srnode.past_parents << dendl;
return false; // not until some snaps are deleted.
}
if (in->has_dirfrags()) {
list<CDir*> ls;
in->get_nested_dirfrags(ls);
for (list<CDir*>::iterator p = ls.begin(); p != ls.end(); ++p) {
(*p)->try_remove_dentries_for_stray();
}
}
}
if (dn->is_replicated()) {
dout(20) << " replicated" << dendl;
return false;
}
if (dn->is_any_leases() || in->is_any_caps()) {
dout(20) << " caps | leases" << dendl;
return false; // wait
}
if (dn->state_test(CDentry::STATE_PURGING)) {
dout(20) << " already purging" << dendl;
return false; // already purging
}
if (in->state_test(CInode::STATE_NEEDSRECOVER) ||
in->state_test(CInode::STATE_RECOVERING)) {
dout(20) << " pending recovery" << dendl;
return false; // don't mess with file size probing
}
if (in->get_num_ref() > (int)in->is_dirty() + (int)in->is_dirty_parent()) {
dout(20) << " too many inode refs" << dendl;
return false;
}
if (dn->get_num_ref() > (int)dn->is_dirty() + !!in->get_num_ref()) {
dout(20) << " too many dn refs" << dendl;
return false;
}
if (delay) {
if (!dn->item_stray.is_on_list()) {
delayed_eval_stray.push_back(&dn->item_stray);
num_strays_delayed++;
logger->set(l_mdc_num_strays_delayed, num_strays_delayed);
}
// don't purge multiversion inode with snap data
} else if (in->snaprealm && in->snaprealm->has_past_parents() &&
!in->old_inodes.empty()) {
// A file with snapshots: we will truncate the HEAD revision
// but leave the metadata intact.
assert(!in->is_dir());
dout(20) << " file has past parents "
<< in->snaprealm->srnode.past_parents << dendl;
if (in->is_file() && in->get_projected_inode()->size > 0) {
enqueue(dn, true); // truncate head objects
}
} else {
// A straightforward file, ready to be purged. Enqueue it.
if (in->is_dir()) {
in->close_dirfrags();
}
enqueue(dn, false);
}
return true;
} else {
/*
* Where a stray has some links, they should be remotes, check
* if we can do anything with them if we happen to have them in
* cache.
*/
eval_remote_stray(dn, NULL);
return false;
}
}
void StrayManager::eval_remote_stray(CDentry *stray_dn, CDentry *remote_dn)
{
assert(stray_dn != NULL);
assert(stray_dn->get_dir()->get_inode()->is_stray());
/* If no remote_dn hinted, pick one arbitrarily */
if (remote_dn == NULL) {
CDentry::linkage_t *stray_dnl = stray_dn->get_projected_linkage();
assert(stray_dnl->is_primary());
CInode *stray_in = stray_dnl->get_inode();
assert(stray_in != NULL);
assert(stray_in->inode.nlink >= 1);
if (!stray_in->remote_parents.empty()) {
remote_dn = *stray_in->remote_parents.begin();
} else {
dout(20) << __func__
<< ": not reintegrating (no remote parents in cache)" << dendl;
return;
}
}
// NOTE: we repeat this check in _rename(), since our submission path is racey.
if (!remote_dn->is_projected()) {
if (remote_dn->is_auth() && remote_dn->dir->can_auth_pin()) {
reintegrate_stray(stray_dn, remote_dn);
} else if (!remote_dn->is_auth() && stray_dn->is_auth()) {
migrate_stray(stray_dn, remote_dn->authority().first);
} else {
dout(20) << __func__ << ": not reintegrating" << dendl;
}
} else {
// don't do anything if the remote parent is projected, or we may
// break user-visible semantics!
dout(20) << __func__ << ": not reintegrating (projected)" << dendl;
}
}
/**
* When hard links exist to an inode whose primary dentry
* is unlinked, the inode gets a stray primary dentry.
*
* We may later "reintegrate" the inode into a remaining
* non-stray dentry (one of what was previously a remote
* dentry) by issuing a rename from the stray to the other
* dentry.
*/
void StrayManager::reintegrate_stray(CDentry *straydn, CDentry *rdn)
{
dout(10) << __func__ << " " << *straydn << " into " << *rdn << dendl;
logger->inc(l_mdc_strays_reintegrated);
// rename it to another mds.
filepath src;
straydn->make_path(src);
filepath dst;
rdn->make_path(dst);
MClientRequest *req = new MClientRequest(CEPH_MDS_OP_RENAME);
req->set_filepath(dst);
req->set_filepath2(src);
req->set_tid(mds->issue_tid());
mds->send_message_mds(req, rdn->authority().first);
}
/**
* Given a dentry within one of my stray directories,
* send it off to a stray directory in another MDS.
*
* This is for use:
* * Case A: when shutting down a rank, we migrate strays
* away from ourselves rather than waiting for purge
* * Case B: when a client request has a trace that refers to
* a stray inode on another MDS, we migrate that inode from
* there to here, in order that we can later re-integrate it
* here.
*
* In case B, the receiver should be calling into eval_stray
* on completion of mv (i.e. inode put), resulting in a subsequent
* reintegration.
*/
void StrayManager::migrate_stray(CDentry *dn, mds_rank_t to)
{
CInode *in = dn->get_linkage()->get_inode();
assert(in);
CInode *diri = dn->dir->get_inode();
assert(diri->is_stray());
dout(10) << "migrate_stray from mds." << MDS_INO_STRAY_OWNER(diri->inode.ino)
<< " to mds." << to
<< " " << *dn << " " << *in << dendl;
logger->inc(l_mdc_strays_migrated);
// rename it to another mds.
filepath src;
dn->make_path(src);
string dname;
in->name_stray_dentry(dname);
filepath dst(dname, MDS_INO_STRAY(to, 0));
MClientRequest *req = new MClientRequest(CEPH_MDS_OP_RENAME);
req->set_filepath(dst);
req->set_filepath2(src);
req->set_tid(mds->issue_tid());
mds->send_message_mds(req, to);
}
StrayManager::StrayManager(MDS *mds)
: delayed_eval_stray(member_offset(CDentry, item_stray)),
mds(mds), logger(NULL),
ops_in_flight(0), files_purging(0),
num_strays(0), num_strays_purging(0), num_strays_delayed(0)
{
assert(mds != NULL);
assert(g_conf->mds_max_purge_ops >= g_conf->filer_max_purge_ops);
}
/**
* For any strays that are enqueued for purge, but
* currently blocked on throttling, clear their
* purging status. Used during MDS rank shutdown
* so that it can migrate these strays instead
* of waiting for them to trickle through the
* queue.
*/
void StrayManager::abort_queue()
{
for (std::list<QueuedStray>::iterator i = ready_for_purge.begin();
i != ready_for_purge.end(); ++i)
{
const QueuedStray &qs = *i;
CDentry *dn = qs.dn;
dout(10) << __func__ << ": aborting enqueued purge " << *dn << dendl;
CDentry::linkage_t *dnl = dn->get_projected_linkage();
assert(dnl);
CInode *in = dnl->get_inode();
assert(in);
// Clear flags set in enqueue
dn->state_clear(CDentry::STATE_PURGING);
dn->put(CDentry::PIN_PURGING);
in->state_clear(CInode::STATE_PURGING);
}
ready_for_purge.clear();
}
void StrayManager::truncate(CDentry *dn, uint32_t op_allowance)
{
CDentry::linkage_t *dnl = dn->get_projected_linkage();
CInode *in = dnl->get_inode();
assert(in);
dout(10) << __func__ << ": " << *dn << " " << *in << dendl;
assert(!dn->is_replicated());
if (dn->item_stray.is_on_list()) {
dn->item_stray.remove_myself();
num_strays_delayed--;
logger->set(l_mdc_num_strays_delayed, num_strays_delayed);
}
num_strays_purging++;
logger->set(l_mdc_num_strays_purging, num_strays_purging);
C_GatherBuilder gather(
g_ceph_context,
new C_OnFinisher(new C_IO_PurgeStrayPurged(this, dn, true, 0),
&mds->finisher));
SnapRealm *realm = in->find_snaprealm();
assert(realm);
dout(10) << " realm " << *realm << dendl;
const SnapContext *snapc = &realm->get_snap_context();
uint64_t period = (uint64_t)in->inode.layout.fl_object_size *
(uint64_t)in->inode.layout.fl_stripe_count;
uint64_t to = in->inode.get_max_size();
to = MAX(in->inode.size, to);
// when truncating a file, the filer does not delete stripe objects that are
// truncated to zero. so we need to purge stripe objects up to the max size
// the file has ever been.
to = MAX(in->inode.max_size_ever, to);
if (period && to > period) {
uint64_t num = (to - 1) / period;
dout(10) << __func__ << " 0~" << to << " objects 0~" << num
<< " snapc " << snapc << " on " << *in << dendl;
mds->filer->purge_range(in->ino(), &in->inode.layout, *snapc,
1, num, ceph_clock_now(g_ceph_context),
0, gather.new_sub());
}
// keep backtrace object
if (period && to > 0) {
mds->filer->zero(in->ino(), &in->inode.layout, *snapc,
0, period, ceph_clock_now(g_ceph_context),
0, true, NULL, gather.new_sub());
}
assert(gather.has_subs());
gather.activate();
}
/**
* Callback: we have logged the update to an inode's metadata
* reflecting it's newly-zeroed length.
*/
void StrayManager::_truncate_stray_logged(CDentry *dn, LogSegment *ls)
{
CInode *in = dn->get_projected_linkage()->get_inode();
dout(10) << __func__ << ": " << *dn << " " << *in << dendl;
dn->state_clear(CDentry::STATE_PURGING);
dn->put(CDentry::PIN_PURGING);
in->pop_and_dirty_projected_inode(ls);
eval_stray(dn);
}

92
src/mds/StrayManager.h Normal file
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@ -0,0 +1,92 @@
// vim: ts=8 sw=2 smarttab
/*
* Ceph - scalable distributed file system
*
* Copyright (C) 2015 Red Hat
*
* This is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 2.1, as published by the Free Software
* Foundation. See file COPYING.
*
*/
#ifndef STRAY_MANAGER_H
#define STRAY_MANAGER_H
#include "include/elist.h"
#include <list>
class MDS;
class PerfCounters;
class CInode;
class CDentry;
class StrayManager
{
protected:
class QueuedStray {
public:
CDentry *dn;
bool trunc;
uint32_t ops_required;
QueuedStray(CDentry *dn_, bool t, uint32_t ops)
: dn(dn_), trunc(t), ops_required(ops) {}
};
// Has passed through eval_stray and still has refs
elist<CDentry*> delayed_eval_stray;
// No more refs, can purge these
std::list<QueuedStray> ready_for_purge;
// Global references for doing I/O
MDS *mds;
PerfCounters *logger;
// Throttled allowances
uint64_t ops_in_flight;
uint64_t files_purging;
// Statistics
uint64_t num_strays;
uint64_t num_strays_purging;
uint64_t num_strays_delayed;
void truncate(CDentry *dn, uint32_t op_allowance);
void purge(CDentry *dn, uint32_t op_allowance);
void _purge_stray_purged(CDentry *dn, uint32_t ops, bool only_head);
void _purge_stray_logged(CDentry *dn, version_t pdv, LogSegment *ls);
void _truncate_stray_logged(CDentry *dn, LogSegment *ls);
friend class StrayManagerIOContext;
friend class StrayManagerContext;
friend class C_PurgeStrayLogged;
friend class C_TruncateStrayLogged;
friend class C_IO_PurgeStrayPurged;
void _advance();
bool _consume(CDentry *dn, bool trunc, uint32_t ops_required);
uint32_t _calculate_ops_required(CInode *in, bool trunc);
void reintegrate_stray(CDentry *dn, CDentry *rlink);
// My public interface is for consumption by MDCache
public:
void enqueue(CDentry *dn, bool trunc);
void advance_delayed();
bool eval_stray(CDentry *dn, bool delay=false);
void eval_remote_stray(CDentry *stray_dn, CDentry *remote_dn=NULL);
void migrate_stray(CDentry *dn, mds_rank_t dest);
StrayManager(MDS *mds);
void set_logger(PerfCounters *l) {logger = l;}
void notify_stray_created();
void notify_stray_removed();
void abort_queue();
};
#endif // STRAY_MANAGER_H