From: "Yan, Zheng" <zheng.z.yan@intel.com>
To: ceph-devel@vger.kernel.org, sage@inktank.com
Cc: "Yan, Zheng" <zheng.z.yan@intel.com>
Subject: [PATCH 13/14] mds: fix race between send_dentry_link() and cache expire
Date: Tue, 11 Dec 2012 16:30:59 +0800 [thread overview]
Message-ID: <1355214660-26354-14-git-send-email-zheng.z.yan@intel.com> (raw)
In-Reply-To: <1355214660-26354-1-git-send-email-zheng.z.yan@intel.com>
From: "Yan, Zheng" <zheng.z.yan@intel.com>
MDentryLink message can race with cache expire, When it arrives at
the target MDS, it's possible there is no corresponding dentry in
the cache. If this race happens, we should expire the replica inode
encoded in the MDentryLink message. But to expire an inode, the MDS
need to know which subtree does the inode belong to, so modify the
MDentryLink message to include this information.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
---
src/mds/MDCache.cc | 85 ++++++++++++++++++++++++++++++----------------
src/messages/MDentryLink.h | 7 +++-
2 files changed, 61 insertions(+), 31 deletions(-)
diff --git a/src/mds/MDCache.cc b/src/mds/MDCache.cc
index 43a3954..3579261 100644
--- a/src/mds/MDCache.cc
+++ b/src/mds/MDCache.cc
@@ -9269,14 +9269,15 @@ void MDCache::send_dentry_link(CDentry *dn)
{
dout(7) << "send_dentry_link " << *dn << dendl;
+ CDir *subtree = get_subtree_root(dn->get_dir());
for (map<int,int>::iterator p = dn->replicas_begin();
p != dn->replicas_end();
p++) {
if (mds->mdsmap->get_state(p->first) < MDSMap::STATE_REJOIN)
continue;
CDentry::linkage_t *dnl = dn->get_linkage();
- MDentryLink *m = new MDentryLink(dn->get_dir()->dirfrag(), dn->name,
- dnl->is_primary());
+ MDentryLink *m = new MDentryLink(subtree->dirfrag(), dn->get_dir()->dirfrag(),
+ dn->name, dnl->is_primary());
if (dnl->is_primary()) {
dout(10) << " primary " << *dnl->get_inode() << dendl;
replicate_inode(dnl->get_inode(), p->first, m->bl);
@@ -9295,32 +9296,48 @@ void MDCache::send_dentry_link(CDentry *dn)
/* This function DOES put the passed message before returning */
void MDCache::handle_dentry_link(MDentryLink *m)
{
- CDir *dir = get_dirfrag(m->get_dirfrag());
- assert(dir);
- CDentry *dn = dir->lookup(m->get_dn());
- assert(dn);
- dout(7) << "handle_dentry_link on " << *dn << dendl;
- CDentry::linkage_t *dnl = dn->get_linkage();
+ CDentry *dn = NULL;
+ CDir *dir = get_dirfrag(m->get_dirfrag());
+ if (!dir) {
+ dout(7) << "handle_dentry_link don't have dirfrag " << m->get_dirfrag() << dendl;
+ } else {
+ dn = dir->lookup(m->get_dn());
+ if (!dn) {
+ dout(7) << "handle_dentry_link don't have dentry " << *dir << " dn " << m->get_dn() << dendl;
+ } else {
+ dout(7) << "handle_dentry_link on " << *dn << dendl;
+ CDentry::linkage_t *dnl = dn->get_linkage();
- assert(!dn->is_auth());
- assert(dnl->is_null());
+ assert(!dn->is_auth());
+ assert(dnl->is_null());
+ }
+ }
bufferlist::iterator p = m->bl.begin();
list<Context*> finished;
-
- if (m->get_is_primary()) {
- // primary link.
- add_replica_inode(p, dn, finished);
- } else {
- // remote link, easy enough.
- inodeno_t ino;
- __u8 d_type;
- ::decode(ino, p);
- ::decode(d_type, p);
- dir->link_remote_inode(dn, ino, d_type);
+ if (dn) {
+ if (m->get_is_primary()) {
+ // primary link.
+ add_replica_inode(p, dn, finished);
+ } else {
+ // remote link, easy enough.
+ inodeno_t ino;
+ __u8 d_type;
+ ::decode(ino, p);
+ ::decode(d_type, p);
+ dir->link_remote_inode(dn, ino, d_type);
+ }
+ } else if (m->get_is_primary()) {
+ CInode *in = add_replica_inode(p, NULL, finished);
+ assert(in->get_num_ref() == 0);
+ assert(in->get_parent_dn() == NULL);
+ MCacheExpire* expire = new MCacheExpire(mds->get_nodeid());
+ expire->add_inode(m->get_subtree(), in->vino(), in->get_replica_nonce());
+ mds->send_message_mds(expire, m->get_source().num());
+ remove_inode(in);
}
-
+
if (!finished.empty())
mds->queue_waiters(finished);
@@ -9352,6 +9369,11 @@ void MDCache::send_dentry_unlink(CDentry *dn, CDentry *straydn, MDRequest *mdr)
/* This function DOES put the passed message before returning */
void MDCache::handle_dentry_unlink(MDentryUnlink *m)
{
+ // straydn
+ CDentry *straydn = NULL;
+ if (m->straybl.length())
+ straydn = add_replica_stray(m->straybl, m->get_source().num());
+
CDir *dir = get_dirfrag(m->get_dirfrag());
if (!dir) {
dout(7) << "handle_dentry_unlink don't have dirfrag " << m->get_dirfrag() << dendl;
@@ -9363,13 +9385,6 @@ void MDCache::handle_dentry_unlink(MDentryUnlink *m)
dout(7) << "handle_dentry_unlink on " << *dn << dendl;
CDentry::linkage_t *dnl = dn->get_linkage();
- // straydn
- CDentry *straydn = NULL;
- if (m->straybl.length()) {
- int from = m->get_source().num();
- straydn = add_replica_stray(m->straybl, from);
- }
-
// open inode?
if (dnl->is_primary()) {
CInode *in = dnl->get_inode();
@@ -9392,8 +9407,9 @@ void MDCache::handle_dentry_unlink(MDentryUnlink *m)
migrator->export_caps(in);
lru.lru_bottouch(straydn); // move stray to end of lru
-
+ straydn = NULL;
} else {
+ assert(!straydn);
assert(dnl->is_remote());
dn->dir->unlink_inode(dn);
}
@@ -9404,6 +9420,15 @@ void MDCache::handle_dentry_unlink(MDentryUnlink *m)
}
}
+ // race with trim_dentry()
+ if (straydn) {
+ assert(straydn->get_num_ref() == 0);
+ assert(straydn->get_linkage()->is_null());
+ map<int, MCacheExpire*> expiremap;
+ trim_dentry(straydn, expiremap);
+ send_expire_messages(expiremap);
+ }
+
m->put();
return;
}
diff --git a/src/messages/MDentryLink.h b/src/messages/MDentryLink.h
index ed02bc2..b351532 100644
--- a/src/messages/MDentryLink.h
+++ b/src/messages/MDentryLink.h
@@ -17,11 +17,13 @@
#define CEPH_MDENTRYLINK_H
class MDentryLink : public Message {
+ dirfrag_t subtree;
dirfrag_t dirfrag;
string dn;
bool is_primary;
public:
+ dirfrag_t get_subtree() { return subtree; }
dirfrag_t get_dirfrag() { return dirfrag; }
string& get_dn() { return dn; }
bool get_is_primary() { return is_primary; }
@@ -30,8 +32,9 @@ class MDentryLink : public Message {
MDentryLink() :
Message(MSG_MDS_DENTRYLINK) { }
- MDentryLink(dirfrag_t df, string& n, bool p) :
+ MDentryLink(dirfrag_t r, dirfrag_t df, string& n, bool p) :
Message(MSG_MDS_DENTRYLINK),
+ subtree(r),
dirfrag(df),
dn(n),
is_primary(p) {}
@@ -46,12 +49,14 @@ public:
void decode_payload() {
bufferlist::iterator p = payload.begin();
+ ::decode(subtree, p);
::decode(dirfrag, p);
::decode(dn, p);
::decode(is_primary, p);
::decode(bl, p);
}
void encode_payload(uint64_t features) {
+ ::encode(subtree, payload);
::encode(dirfrag, payload);
::encode(dn, payload);
::encode(is_primary, payload);
--
1.7.11.7
next prev parent reply other threads:[~2012-12-11 8:31 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-11 8:30 [PATCH 00/14] fixes for MDS Yan, Zheng
2012-12-11 8:30 ` [PATCH 01/14] mds: fix journaling issue regarding rstat accounting Yan, Zheng
2012-12-11 8:30 ` [PATCH 02/14] mds: alllow handle_client_readdir() fetching freezing dir Yan, Zheng
2012-12-11 8:30 ` [PATCH 03/14] mds: properly mark dirfrag dirty Yan, Zheng
2012-12-11 8:30 ` [PATCH 04/14] mds: no bloom filter for replica dir Yan, Zheng
2012-12-11 8:30 ` [PATCH 05/14] mds: set want_base_dir to false for MDCache::discover_ino() Yan, Zheng
2012-12-11 8:30 ` [PATCH 06/14] mds: fix error hanlding in MDCache::handle_discover_reply() Yan, Zheng
2012-12-11 8:30 ` [PATCH 07/14] mds: always send discover if want_xlocked is true Yan, Zheng
2012-12-11 8:30 ` [PATCH 08/14] mds: re-issue caps after importing caps Yan, Zheng
2012-12-11 8:30 ` [PATCH 09/14] mds: take export lock set before sending MExportDirDiscover Yan, Zheng
2012-12-11 8:30 ` [PATCH 10/14] mds: don't retry readdir request after issuing caps Yan, Zheng
2012-12-11 8:30 ` [PATCH 11/14] mds: delay processing cache expire when state >= EXPORT_EXPORTING Yan, Zheng
2012-12-11 8:30 ` [PATCH 12/14] mds: fix file existing check in Server::handle_client_openc() Yan, Zheng
2012-12-11 8:30 ` Yan, Zheng [this message]
2012-12-11 8:31 ` [PATCH 14/14] mds: compare sessionmap version before replaying imported sessions Yan, Zheng
2012-12-11 8:33 ` [PATCH 00/14] fixes for MDS Yan, Zheng
2012-12-11 17:11 ` Sage Weil
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