From: "Yan, Zheng" <zheng.z.yan@xxxxxxxxx> Fixes #5380 Signed-off-by: Yan, Zheng <zheng.z.yan@xxxxxxxxx> --- src/client/Client.cc | 8 ++++---- src/librbd/ImageCtx.cc | 4 ++-- src/librbd/internal.cc | 10 +++++----- src/osd/osd_types.h | 6 ++++-- src/osdc/Filer.cc | 2 +- src/osdc/Filer.h | 12 ++++++------ src/osdc/ObjectCacher.cc | 28 ++++++++++++++-------------- src/osdc/ObjectCacher.h | 17 ++++++++++------- src/osdc/Objecter.h | 8 ++++---- src/osdc/Striper.cc | 45 ++++++++++++++++++++++++++++++++++++++++++--- src/osdc/Striper.h | 11 +++++++---- src/test/test_striper.cc | 5 ++++- 12 files changed, 103 insertions(+), 53 deletions(-) diff --git a/src/client/Client.cc b/src/client/Client.cc index 80cce8a..45ad949 100644 --- a/src/client/Client.cc +++ b/src/client/Client.cc @@ -2665,7 +2665,7 @@ void Client::_invalidate_inode_cache(Inode *in, int64_t off, int64_t len, bool k // invalidate our userspace inode cache if (cct->_conf->client_oc) { vector<ObjectExtent> ls; - Striper::file_to_extents(cct, in->ino, &in->layout, off, len, ls); + Striper::file_to_extents(cct, in->ino, &in->layout, off, len, in->truncate_size, ls); objectcacher->discard_set(&in->oset, ls); } @@ -7740,7 +7740,7 @@ int Client::get_file_extent_osds(int fd, loff_t off, loff_t *len, vector<int>& o Inode *in = f->inode; vector<ObjectExtent> extents; - Striper::file_to_extents(cct, in->ino, &in->layout, off, 1, extents); + Striper::file_to_extents(cct, in->ino, &in->layout, off, 1, in->truncate_size, extents); assert(extents.size() == 1); pg_t pg = osdmap->object_locator_to_pg(extents[0].oid, extents[0].oloc); @@ -7787,7 +7787,7 @@ int Client::get_file_stripe_address(int fd, loff_t offset, vector<entity_addr_t> // which object? vector<ObjectExtent> extents; - Striper::file_to_extents(cct, in->ino, &in->layout, offset, 1, extents); + Striper::file_to_extents(cct, in->ino, &in->layout, offset, 1, in->truncate_size, extents); assert(extents.size() == 1); // now we have the object and its 'layout' @@ -7828,7 +7828,7 @@ int Client::enumerate_layout(int fd, vector<ObjectExtent>& result, Inode *in = f->inode; // map to a list of extents - Striper::file_to_extents(cct, in->ino, &in->layout, offset, length, result); + Striper::file_to_extents(cct, in->ino, &in->layout, offset, length, in->truncate_size, result); ldout(cct, 3) << "enumerate_layout(" << fd << ", " << length << ", " << offset << ") = 0" << dendl; return 0; diff --git a/src/librbd/ImageCtx.cc b/src/librbd/ImageCtx.cc index 6796bc8..2ab5fd9 100644 --- a/src/librbd/ImageCtx.cc +++ b/src/librbd/ImageCtx.cc @@ -475,7 +475,7 @@ namespace librbd { snap_lock.get_read(); ObjectCacher::OSDRead *rd = object_cacher->prepare_read(snap_id, bl, 0); snap_lock.put_read(); - ObjectExtent extent(o, 0 /* a lie */, off, len); + ObjectExtent extent(o, 0 /* a lie */, off, len, 0); extent.oloc.pool = data_ctx.get_id(); extent.buffer_extents.push_back(make_pair(0, len)); rd->extents.push_back(extent); @@ -492,7 +492,7 @@ namespace librbd { ObjectCacher::OSDWrite *wr = object_cacher->prepare_write(snapc, bl, utime_t(), 0); snap_lock.put_read(); - ObjectExtent extent(o, 0, off, len); + ObjectExtent extent(o, 0, off, len, 0); extent.oloc.pool = data_ctx.get_id(); extent.buffer_extents.push_back(make_pair(0, len)); wr->extents.push_back(extent); diff --git a/src/librbd/internal.cc b/src/librbd/internal.cc index 789ef86..1fd7942 100644 --- a/src/librbd/internal.cc +++ b/src/librbd/internal.cc @@ -184,7 +184,7 @@ namespace librbd { if (delete_off > newsize) { vector<ObjectExtent> extents; Striper::file_to_extents(ictx->cct, ictx->format_string, &ictx->layout, - newsize, delete_off - newsize, extents); + newsize, delete_off - newsize, 0, extents); for (vector<ObjectExtent>::iterator p = extents.begin(); p != extents.end(); ++p) { @@ -2482,7 +2482,7 @@ reprotect_and_return_err: // map to extents map<object_t,vector<ObjectExtent> > object_extents; Striper::file_to_extents(ictx->cct, ictx->format_string, &ictx->layout, - off, read_len, object_extents, 0); + off, read_len, 0, object_extents, 0); // get snap info for each object for (map<object_t,vector<ObjectExtent> >::iterator p = object_extents.begin(); @@ -2880,7 +2880,7 @@ reprotect_and_return_err: // map vector<ObjectExtent> extents; - Striper::file_to_extents(ictx->cct, ictx->format_string, &ictx->layout, off, mylen, extents); + Striper::file_to_extents(ictx->cct, ictx->format_string, &ictx->layout, off, mylen, 0, extents); c->get(); c->init_time(ictx, AIO_TYPE_WRITE); @@ -2960,7 +2960,7 @@ reprotect_and_return_err: // map vector<ObjectExtent> extents; - Striper::file_to_extents(ictx->cct, ictx->format_string, &ictx->layout, off, len, extents); + Striper::file_to_extents(ictx->cct, ictx->format_string, &ictx->layout, off, len, 0, extents); c->get(); c->init_time(ictx, AIO_TYPE_DISCARD); @@ -3056,7 +3056,7 @@ reprotect_and_return_err: return r; Striper::file_to_extents(ictx->cct, ictx->format_string, &ictx->layout, - p->first, len, object_extents, buffer_ofs); + p->first, len, 0, object_extents, buffer_ofs); buffer_ofs += len; } diff --git a/src/osd/osd_types.h b/src/osd/osd_types.h index a266fff..a0b6455 100644 --- a/src/osd/osd_types.h +++ b/src/osd/osd_types.h @@ -1637,13 +1637,15 @@ class ObjectExtent { uint64_t objectno; uint64_t offset; // in object uint64_t length; // in object + uint64_t truncate_size; // in object object_locator_t oloc; // object locator (pool etc) vector<pair<uint64_t,uint64_t> > buffer_extents; // off -> len. extents in buffer being mapped (may be fragmented bc of striping!) - ObjectExtent() : objectno(0), offset(0), length(0) {} - ObjectExtent(object_t o, uint64_t ono, uint64_t off, uint64_t l) : oid(o), objectno(ono), offset(off), length(l) { } + ObjectExtent() : objectno(0), offset(0), length(0), truncate_size(0) {} + ObjectExtent(object_t o, uint64_t ono, uint64_t off, uint64_t l, uint64_t ts) : + oid(o), objectno(ono), offset(off), length(l), truncate_size(ts) { } }; inline ostream& operator<<(ostream& out, const ObjectExtent &ex) diff --git a/src/osdc/Filer.cc b/src/osdc/Filer.cc index aec2910..7eb4ad6 100644 --- a/src/osdc/Filer.cc +++ b/src/osdc/Filer.cc @@ -102,7 +102,7 @@ void Filer::_probe(Probe *probe) probe->known_size.clear(); probe->probing.clear(); Striper::file_to_extents(cct, probe->ino, &probe->layout, - probe->probing_off, probe->probing_len, probe->probing); + probe->probing_off, probe->probing_len, 0, probe->probing); for (vector<ObjectExtent>::iterator p = probe->probing.begin(); p != probe->probing.end(); diff --git a/src/osdc/Filer.h b/src/osdc/Filer.h index cde4502..86ff601 100644 --- a/src/osdc/Filer.h +++ b/src/osdc/Filer.h @@ -107,7 +107,7 @@ class Filer { Context *onfinish) { assert(snap); // (until there is a non-NOSNAP write) vector<ObjectExtent> extents; - Striper::file_to_extents(cct, ino, layout, offset, len, extents); + Striper::file_to_extents(cct, ino, layout, offset, len, 0, extents); objecter->sg_read(extents, snap, bl, flags, onfinish); return 0; } @@ -124,7 +124,7 @@ class Filer { Context *onfinish) { assert(snap); // (until there is a non-NOSNAP write) vector<ObjectExtent> extents; - Striper::file_to_extents(cct, ino, layout, offset, len, extents); + Striper::file_to_extents(cct, ino, layout, offset, len, truncate_size, extents); objecter->sg_read_trunc(extents, snap, bl, flags, truncate_size, truncate_seq, onfinish); return 0; @@ -141,7 +141,7 @@ class Filer { Context *onack, Context *oncommit) { vector<ObjectExtent> extents; - Striper::file_to_extents(cct, ino, layout, offset, len, extents); + Striper::file_to_extents(cct, ino, layout, offset, len, 0, extents); objecter->sg_write(extents, snapc, bl, mtime, flags, onack, oncommit); return 0; } @@ -159,7 +159,7 @@ class Filer { Context *onack, Context *oncommit) { vector<ObjectExtent> extents; - Striper::file_to_extents(cct, ino, layout, offset, len, extents); + Striper::file_to_extents(cct, ino, layout, offset, len, truncate_size, extents); objecter->sg_write_trunc(extents, snapc, bl, mtime, flags, truncate_size, truncate_seq, onack, oncommit); return 0; @@ -176,7 +176,7 @@ class Filer { Context *onack, Context *oncommit) { vector<ObjectExtent> extents; - Striper::file_to_extents(cct, ino, layout, offset, len, extents); + Striper::file_to_extents(cct, ino, layout, offset, len, 0, extents); if (extents.size() == 1) { vector<OSDOp> ops(1); ops[0].op.op = CEPH_OSD_OP_TRIMTRUNC; @@ -211,7 +211,7 @@ class Filer { Context *onack, Context *oncommit) { vector<ObjectExtent> extents; - Striper::file_to_extents(cct, ino, layout, offset, len, extents); + Striper::file_to_extents(cct, ino, layout, offset, len, 0, extents); if (extents.size() == 1) { if (extents[0].offset == 0 && extents[0].length == layout->fl_object_size) objecter->remove(extents[0].oid, extents[0].oloc, diff --git a/src/osdc/ObjectCacher.cc b/src/osdc/ObjectCacher.cc index 56c56d6..0481c6c 100644 --- a/src/osdc/ObjectCacher.cc +++ b/src/osdc/ObjectCacher.cc @@ -555,19 +555,25 @@ void ObjectCacher::perf_stop() /* private */ ObjectCacher::Object *ObjectCacher::get_object(sobject_t oid, ObjectSet *oset, - object_locator_t &l) + object_locator_t &l, + uint64_t truncate_size, + uint64_t truncate_seq) { assert(lock.is_locked()); // have it? if ((uint32_t)l.pool < objects.size()) { - if (objects[l.pool].count(oid)) - return objects[l.pool][oid]; + if (objects[l.pool].count(oid)) { + Object *o = objects[l.pool][oid]; + o->truncate_size = truncate_size; + o->truncate_seq = truncate_seq; + return o; + } } else { objects.resize(l.pool+1); } // create it. - Object *o = new Object(this, oid, oset, l); + Object *o = new Object(this, oid, oset, l, truncate_size, truncate_seq); objects[l.pool][oid] = o; ob_lru.lru_insert_top(o); return o; @@ -600,13 +606,10 @@ void ObjectCacher::bh_read(BufferHead *bh) // finisher C_ReadFinish *onfinish = new C_ReadFinish(this, bh->ob, bh->start(), bh->length()); - - ObjectSet *oset = bh->ob->oset; - // go writeback_handler.read(bh->ob->get_oid(), bh->ob->get_oloc(), bh->start(), bh->length(), bh->ob->get_snap(), - &onfinish->bl, oset->truncate_size, oset->truncate_seq, + &onfinish->bl, bh->ob->truncate_size, bh->ob->truncate_seq, onfinish); ++reads_outstanding; } @@ -786,14 +789,11 @@ void ObjectCacher::bh_write(BufferHead *bh) // finishers C_WriteCommit *oncommit = new C_WriteCommit(this, bh->ob->oloc.pool, bh->ob->get_soid(), bh->start(), bh->length()); - - ObjectSet *oset = bh->ob->oset; - // go tid_t tid = writeback_handler.write(bh->ob->get_oid(), bh->ob->get_oloc(), bh->start(), bh->length(), bh->snapc, bh->bl, bh->last_write, - oset->truncate_size, oset->truncate_seq, + bh->ob->truncate_size, bh->ob->truncate_seq, oncommit); ldout(cct, 20) << " tid " << tid << " on " << bh->ob->get_oid() << dendl; @@ -1022,7 +1022,7 @@ int ObjectCacher::_readx(OSDRead *rd, ObjectSet *oset, Context *onfinish, // get Object cache sobject_t soid(ex_it->oid, rd->snap); - Object *o = get_object(soid, oset, ex_it->oloc); + Object *o = get_object(soid, oset, ex_it->oloc, ex_it->truncate_size, oset->truncate_seq); touch_ob(o); // does not exist and no hits? @@ -1256,7 +1256,7 @@ int ObjectCacher::writex(OSDWrite *wr, ObjectSet *oset, Mutex& wait_on_lock, ++ex_it) { // get object cache sobject_t soid(ex_it->oid, CEPH_NOSNAP); - Object *o = get_object(soid, oset, ex_it->oloc); + Object *o = get_object(soid, oset, ex_it->oloc, ex_it->truncate_size, oset->truncate_seq); // map it all into a single bufferhead. BufferHead *bh = o->map_write(wr); diff --git a/src/osdc/ObjectCacher.h b/src/osdc/ObjectCacher.h index 80a90bd..4441cfa 100644 --- a/src/osdc/ObjectCacher.h +++ b/src/osdc/ObjectCacher.h @@ -171,6 +171,7 @@ class ObjectCacher { ObjectSet *oset; xlist<Object*>::item set_item; object_locator_t oloc; + uint64_t truncate_size, truncate_seq; bool complete; bool exists; @@ -190,10 +191,12 @@ class ObjectCacher { Object(const Object& other); const Object& operator=(const Object& other); - Object(ObjectCacher *_oc, sobject_t o, ObjectSet *os, object_locator_t& l) : + Object(ObjectCacher *_oc, sobject_t o, ObjectSet *os, object_locator_t& l, + uint64_t ts, uint64_t tq) : ref(0), oc(_oc), oid(o), oset(os), set_item(this), oloc(l), + truncate_size(ts), truncate_seq(tq), complete(false), exists(true), last_write_tid(0), last_commit_tid(0), dirty_or_tx(0) { @@ -363,8 +366,8 @@ class ObjectCacher { return NULL; } - Object *get_object(sobject_t oid, ObjectSet *oset, - object_locator_t &l); + Object *get_object(sobject_t oid, ObjectSet *oset, object_locator_t &l, + uint64_t truncate_size, uint64_t truncate_seq); void close_object(Object *ob); // bh stats @@ -626,7 +629,7 @@ public: int file_is_cached(ObjectSet *oset, ceph_file_layout *layout, snapid_t snapid, loff_t offset, uint64_t len) { vector<ObjectExtent> extents; - Striper::file_to_extents(cct, oset->ino, layout, offset, len, extents); + Striper::file_to_extents(cct, oset->ino, layout, offset, len, oset->truncate_size, extents); return is_cached(oset, extents, snapid); } @@ -636,7 +639,7 @@ public: int flags, Context *onfinish) { OSDRead *rd = prepare_read(snapid, bl, flags); - Striper::file_to_extents(cct, oset->ino, layout, offset, len, rd->extents); + Striper::file_to_extents(cct, oset->ino, layout, offset, len, oset->truncate_size, rd->extents); return readx(rd, oset, onfinish); } @@ -645,14 +648,14 @@ public: bufferlist& bl, utime_t mtime, int flags, Mutex& wait_on_lock) { OSDWrite *wr = prepare_write(snapc, bl, mtime, flags); - Striper::file_to_extents(cct, oset->ino, layout, offset, len, wr->extents); + Striper::file_to_extents(cct, oset->ino, layout, offset, len, oset->truncate_size, wr->extents); return writex(wr, oset, wait_on_lock, NULL); } bool file_flush(ObjectSet *oset, ceph_file_layout *layout, const SnapContext& snapc, loff_t offset, uint64_t len, Context *onfinish) { vector<ObjectExtent> extents; - Striper::file_to_extents(cct, oset->ino, layout, offset, len, extents); + Striper::file_to_extents(cct, oset->ino, layout, offset, len, oset->truncate_size, extents); return flush_set(oset, extents, onfinish); } }; diff --git a/src/osdc/Objecter.h b/src/osdc/Objecter.h index bc4b0ae..b4086f6 100644 --- a/src/osdc/Objecter.h +++ b/src/osdc/Objecter.h @@ -1696,14 +1696,14 @@ public: uint64_t trunc_size, __u32 trunc_seq, Context *onfinish) { if (extents.size() == 1) { read_trunc(extents[0].oid, extents[0].oloc, extents[0].offset, extents[0].length, - snap, bl, flags, trunc_size, trunc_seq, onfinish); + snap, bl, flags, extents[0].truncate_size, trunc_seq, onfinish); } else { C_GatherBuilder gather(cct); vector<bufferlist> resultbl(extents.size()); int i=0; for (vector<ObjectExtent>::iterator p = extents.begin(); p != extents.end(); ++p) { read_trunc(p->oid, p->oloc, p->offset, p->length, - snap, &resultbl[i++], flags, trunc_size, trunc_seq, gather.new_sub()); + snap, &resultbl[i++], flags, p->truncate_size, trunc_seq, gather.new_sub()); } gather.set_finisher(new C_SGRead(this, extents, resultbl, bl, onfinish)); gather.activate(); @@ -1719,7 +1719,7 @@ public: Context *onack, Context *oncommit) { if (extents.size() == 1) { write_trunc(extents[0].oid, extents[0].oloc, extents[0].offset, extents[0].length, - snapc, bl, mtime, flags, trunc_size, trunc_seq, onack, oncommit); + snapc, bl, mtime, flags, extents[0].truncate_size, trunc_seq, onack, oncommit); } else { C_GatherBuilder gack(cct, onack); C_GatherBuilder gcom(cct, oncommit); @@ -1731,7 +1731,7 @@ public: bl.copy(bit->first, bit->second, cur); assert(cur.length() == p->length); write_trunc(p->oid, p->oloc, p->offset, p->length, - snapc, cur, mtime, flags, trunc_size, trunc_seq, + snapc, cur, mtime, flags, p->truncate_size, trunc_seq, onack ? gack.new_sub():0, oncommit ? gcom.new_sub():0); } diff --git a/src/osdc/Striper.cc b/src/osdc/Striper.cc index b062845..bde3284 100644 --- a/src/osdc/Striper.cc +++ b/src/osdc/Striper.cc @@ -28,18 +28,19 @@ void Striper::file_to_extents(CephContext *cct, const char *object_format, ceph_file_layout *layout, - uint64_t offset, uint64_t len, + uint64_t offset, uint64_t len, uint64_t trunc_size, vector<ObjectExtent>& extents, uint64_t buffer_offset) { map<object_t,vector<ObjectExtent> > object_extents; - file_to_extents(cct, object_format, layout, offset, len, object_extents, buffer_offset); + file_to_extents(cct, object_format, layout, offset, len, trunc_size, + object_extents, buffer_offset); assimilate_extents(object_extents, extents); } void Striper::file_to_extents(CephContext *cct, const char *object_format, ceph_file_layout *layout, - uint64_t offset, uint64_t len, + uint64_t offset, uint64_t len, uint64_t trunc_size, map<object_t,vector<ObjectExtent> >& object_extents, uint64_t buffer_offset) { @@ -108,6 +109,8 @@ void Striper::file_to_extents(CephContext *cct, const char *object_format, ex->offset = x_offset; ex->length = x_len; + ex->truncate_size = object_truncate_size(cct, layout, objectno, trunc_size); + ldout(cct, 20) << " added new " << *ex << dendl; } else { // add to extent @@ -174,6 +177,42 @@ void Striper::extent_to_file(CephContext *cct, ceph_file_layout *layout, } } +uint64_t Striper::object_truncate_size(CephContext *cct, ceph_file_layout *layout, + uint64_t objectno, uint64_t trunc_size) +{ + uint64_t obj_trunc_size; + if (trunc_size == 0 || trunc_size == (uint64_t)-1) { + obj_trunc_size = trunc_size; + } else { + __u32 object_size = layout->fl_object_size; + __u32 su = layout->fl_stripe_unit; + __u32 stripe_count = layout->fl_stripe_count; + assert(object_size >= su); + uint64_t stripes_per_object = object_size / su; + + uint64_t objectsetno = objectno / stripe_count; + uint64_t trunc_objectsetno = trunc_size / object_size / stripe_count; + if (objectsetno > trunc_objectsetno) + obj_trunc_size = 0; + else if (objectsetno < trunc_objectsetno) + obj_trunc_size = object_size; + else { + uint64_t trunc_blockno = trunc_size / su; + uint64_t trunc_stripeno = trunc_blockno / stripe_count; + uint64_t trunc_stripepos = trunc_blockno % stripe_count; + uint64_t trunc_objectno = trunc_objectsetno * stripe_count + trunc_stripepos; + if (objectno < trunc_objectno) + obj_trunc_size = ((trunc_stripeno % stripes_per_object) + 1) * su; + else if (objectno > trunc_objectno) + obj_trunc_size = (trunc_stripeno % stripes_per_object) * su; + else + obj_trunc_size = (trunc_stripeno % stripes_per_object) * su + (trunc_size % su); + } + } + ldout(cct, 20) << "object_truncate_size " << objectno << " " + << trunc_size << "->" << obj_trunc_size << dendl; + return obj_trunc_size; +} // StripedReadResult diff --git a/src/osdc/Striper.h b/src/osdc/Striper.h index 9f05635..bd61fc8 100644 --- a/src/osdc/Striper.h +++ b/src/osdc/Striper.h @@ -30,25 +30,25 @@ class CephContext; */ static void file_to_extents(CephContext *cct, const char *object_format, ceph_file_layout *layout, - uint64_t offset, uint64_t len, + uint64_t offset, uint64_t len, uint64_t trunc_size, map<object_t, vector<ObjectExtent> >& extents, uint64_t buffer_offset=0); static void file_to_extents(CephContext *cct, const char *object_format, ceph_file_layout *layout, - uint64_t offset, uint64_t len, + uint64_t offset, uint64_t len, uint64_t trunc_size, vector<ObjectExtent>& extents, uint64_t buffer_offset=0); static void file_to_extents(CephContext *cct, inodeno_t ino, ceph_file_layout *layout, - uint64_t offset, uint64_t len, + uint64_t offset, uint64_t len, uint64_t trunc_size, vector<ObjectExtent>& extents) { // generate prefix/format char buf[32]; snprintf(buf, sizeof(buf), "%llx.%%08llx", (long long unsigned)ino); - file_to_extents(cct, buf, layout, offset, len, extents); + file_to_extents(cct, buf, layout, offset, len, trunc_size, extents); } static void assimilate_extents(map<object_t,vector<ObjectExtent> >& object_extents, @@ -61,6 +61,9 @@ class CephContext; uint64_t objectno, uint64_t off, uint64_t len, vector<pair<uint64_t, uint64_t> >& extents); + static uint64_t object_truncate_size(CephContext *cct, ceph_file_layout *layout, + uint64_t objectno, uint64_t trunc_size); + /* * helper to assemble a striped result */ diff --git a/src/test/test_striper.cc b/src/test/test_striper.cc index d3e9285..262fba3 100644 --- a/src/test/test_striper.cc +++ b/src/test/test_striper.cc @@ -16,11 +16,14 @@ TEST(Striper, Stripe1) l.fl_stripe_count = 3; vector<ObjectExtent> ex; - Striper::file_to_extents(g_ceph_context, 1, &l, 5006035, 46419, ex); + Striper::file_to_extents(g_ceph_context, 1, &l, 5006035, 46419, 5006035, ex); cout << "result " << ex << std::endl; ASSERT_EQ(3u, ex.size()); + ASSERT_EQ(98304u, ex[0].truncate_size); + ASSERT_EQ(ex[1].offset, ex[1].truncate_size); + ASSERT_EQ(94208u, ex[2].truncate_size); } -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html