From e7424897a1272490b78c08f78ce7b260eb014f20 Mon Sep 17 00:00:00 2001 From: Volker Lendecke Date: Mon, 20 May 2019 16:01:03 +0200 Subject: [PATCH] ctdb: Make TDB_SEQNUM work synchronously with ctdb Old war story completely from memory, I could not find the commit that introduced TDB_SEQNUM so far...: Back in the days when ctdb was initially developed, TDB_SEQNUM's only user was the notify.tdb that held one huge record for all notify records. With that use case in mind it made perfect sense to keep the SEQNUM stable locally, sacrificing precision. By now notify.tdb is long gone, an the only user of TDB_SEQNUM right now is brlock.tdb, which contains special case code for the imprecise ctdb implementation of TDB_SEQNUM. With this commit, that special code can go: The TDB_SEQNUM will also increment when just the DMASTER header field changes, indicating to smbd that someone else might have changed the record. This will of course increase the SEQNUM frequency, but it should not increase the load on ctdb: If you look at the brlock.c workaround, it just does not do the caching that is possible with precise TDB_SEQNUMs working. How did I get here? I want to move brl_num_read_oplocks() from brlock.tdb into locking.tdb, and for that I need precise TDB_SEQNUMs for locking.tdb. Signed-off-by: Volker Lendecke Reviewed-by: Jeremy Allison Autobuild-User(master): Jeremy Allison Autobuild-Date(master): Fri May 24 00:42:17 UTC 2019 on sn-devel-184 --- ctdb/common/ctdb_ltdb.c | 19 ------------------- ctdb/server/ctdb_ltdb_server.c | 20 -------------------- 2 files changed, 39 deletions(-) diff --git a/ctdb/common/ctdb_ltdb.c b/ctdb/common/ctdb_ltdb.c index de4f44895e4..1fc9ce28c1b 100644 --- a/ctdb/common/ctdb_ltdb.c +++ b/ctdb/common/ctdb_ltdb.c @@ -231,7 +231,6 @@ int ctdb_ltdb_store(struct ctdb_db_context *ctdb_db, TDB_DATA key, TDB_DATA rec[2]; uint32_t hsize = sizeof(struct ctdb_ltdb_header); int ret; - bool seqnum_suppressed = false; if (ctdb_db->ctdb_ltdb_store_fn) { return ctdb_db->ctdb_ltdb_store_fn(ctdb_db, key, header, data); @@ -260,28 +259,10 @@ int ctdb_ltdb_store(struct ctdb_db_context *ctdb_db, TDB_DATA key, rec[1].dsize = data.dsize; rec[1].dptr = data.dptr; - /* Databases with seqnum updates enabled only get their seqnum - changes when/if we modify the data */ - if (ctdb_db->seqnum_update != NULL) { - TDB_DATA old; - old = tdb_fetch(ctdb_db->ltdb->tdb, key); - - if ((old.dsize == hsize + data.dsize) && - memcmp(old.dptr+hsize, data.dptr, data.dsize) == 0) { - tdb_remove_flags(ctdb_db->ltdb->tdb, TDB_SEQNUM); - seqnum_suppressed = true; - } - if (old.dptr != NULL) { - free(old.dptr); - } - } ret = tdb_storev(ctdb_db->ltdb->tdb, key, rec, 2, TDB_REPLACE); if (ret != 0) { DEBUG(DEBUG_ERR, (__location__ " Failed to store dynamic data\n")); } - if (seqnum_suppressed) { - tdb_add_flags(ctdb_db->ltdb->tdb, TDB_SEQNUM); - } return ret; } diff --git a/ctdb/server/ctdb_ltdb_server.c b/ctdb/server/ctdb_ltdb_server.c index 91064d19b73..8cc6c4ba4cc 100644 --- a/ctdb/server/ctdb_ltdb_server.c +++ b/ctdb/server/ctdb_ltdb_server.c @@ -62,7 +62,6 @@ static int ctdb_ltdb_store_server(struct ctdb_db_context *ctdb_db, TDB_DATA rec[2]; uint32_t hsize = sizeof(struct ctdb_ltdb_header); int ret; - bool seqnum_suppressed = false; bool keep = false; bool schedule_for_deletion = false; bool remove_from_delete_queue = false; @@ -192,22 +191,6 @@ store: rec[1].dsize = data.dsize; rec[1].dptr = data.dptr; - /* Databases with seqnum updates enabled only get their seqnum - changes when/if we modify the data */ - if (ctdb_db->seqnum_update != NULL) { - TDB_DATA old; - old = tdb_fetch(ctdb_db->ltdb->tdb, key); - - if ((old.dsize == hsize + data.dsize) && - memcmp(old.dptr + hsize, data.dptr, data.dsize) == 0) { - tdb_remove_flags(ctdb_db->ltdb->tdb, TDB_SEQNUM); - seqnum_suppressed = true; - } - if (old.dptr != NULL) { - free(old.dptr); - } - } - DEBUG(DEBUG_DEBUG, (__location__ " db[%s]: %s record: hash[0x%08x]\n", ctdb_db->db_name, keep?"storing":"deleting", @@ -237,9 +220,6 @@ store: schedule_for_deletion = false; remove_from_delete_queue = false; } - if (seqnum_suppressed) { - tdb_add_flags(ctdb_db->ltdb->tdb, TDB_SEQNUM); - } if (schedule_for_deletion) { int ret2; -- 2.34.1