diff options
| author | Yan, Zheng <zheng.z.yan@intel.com> | 2013-09-19 13:48:38 +0800 |
|---|---|---|
| committer | Yan, Zheng <zheng.z.yan@intel.com> | 2013-09-24 08:45:55 +0800 |
| commit | c436bd417429c5ddedf90a53580287190396d516 (patch) | |
| tree | 38a8fc2abdbd791254c2b82d01149a84266d178f | |
| parent | d3dc42bdb8e148a7d7e5520d015e498f2fa7c1a0 (diff) | |
| download | ceph-c436bd417429c5ddedf90a53580287190396d516.tar.gz | |
mds: handle dirfrag mismatch when processing readdir request
If client has outdated dirfrags information, readdir request from
it may specify a non-existing dirfrag. Current method to handle this
case is reply -EAGAIN and let client retry. When client receives the
the -EAGAIN reply, it need to refresh its dirfrags information first,
then re-send the readdir request.
A better way to handle client request that specify a non-existing
dirfrag is: MDS chooses a approximate dirfrag, then handle the request
like normal. When client receives the readdir reply, it will also
update its dirfrags information.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
| -rw-r--r-- | src/mds/Server.cc | 21 |
1 files changed, 9 insertions, 12 deletions
diff --git a/src/mds/Server.cc b/src/mds/Server.cc index c6f48c2a1f7..a85500257d3 100644 --- a/src/mds/Server.cc +++ b/src/mds/Server.cc @@ -2734,13 +2734,15 @@ void Server::handle_client_readdir(MDRequest *mdr) // which frag? frag_t fg = (__u32)req->head.args.readdir.frag; - dout(10) << " frag " << fg << dendl; + string offset_str = req->get_path2(); + dout(10) << " frag " << fg << " offset '" << offset_str << "'" << dendl; // does the frag exist? if (diri->dirfragtree[fg.value()] != fg) { - dout(10) << "frag " << fg << " doesn't appear in fragtree " << diri->dirfragtree << dendl; - reply_request(mdr, -EAGAIN); - return; + frag_t newfg = diri->dirfragtree[fg.value()]; + dout(10) << " adjust frag " << fg << " -> " << newfg << " " << diri->dirfragtree << dendl; + fg = newfg; + offset_str.clear(); } CDir *dir = try_open_auth_dirfrag(diri, fg, mdr); @@ -2769,12 +2771,7 @@ void Server::handle_client_readdir(MDRequest *mdr) mdr->now = ceph_clock_now(g_ceph_context); snapid_t snapid = mdr->snapid; - - string offset_str = req->get_path2(); - const char *offset = offset_str.length() ? offset_str.c_str() : 0; - - dout(10) << "snapid " << snapid << " offset '" << offset_str << "'" << dendl; - + dout(10) << "snapid " << snapid << dendl; // purge stale snap data? const set<snapid_t> *snaps = 0; @@ -2830,7 +2827,7 @@ void Server::handle_client_readdir(MDRequest *mdr) continue; } - if (offset && strcmp(dn->get_name().c_str(), offset) <= 0) + if (!offset_str.empty() && dn->get_name().compare(offset_str) <= 0) continue; CInode *in = dnl->get_inode(); @@ -2900,7 +2897,7 @@ void Server::handle_client_readdir(MDRequest *mdr) } __u8 end = (it == dir->end()); - __u8 complete = (end && !offset); // FIXME: what purpose does this serve + __u8 complete = (end && offset_str.empty()); // FIXME: what purpose does this serve // finish final blob ::encode(numfiles, dirbl); |