The branch, master has been updated
via d956608 tdb: consolidate tdb allocation code - re-use dead records
at hash top.
from 1e1b7b1 torture: add local verification trailer parsing test
http://gitweb.samba.org/?p=samba.git;a=shortlog;h=master
- Log -----------------------------------------------------------------
commit d9566085c68b9da6d46a5916a6cca33ca03befce
Author: Michael Adam <[email protected]>
Date: Wed Mar 19 13:38:17 2014 +0100
tdb: consolidate tdb allocation code - re-use dead records at hash top.
When in tdb_store we re-use a dead record reactivated from the
target hash chain itself, we currently leave it in its place in
the chain. When we re-use a dead record from a different chain or
from the freelist instead, we insert it at the beginning of the
target chain.
This patch changes the behaviour to always newly store a
record at the beginning of the hash chain. This removes
a special case and hence simplifies the allocation code.
On the other hand side, it introduces two additioal tdb_ofs_write
calls for the in-chain-case.
Note the subtelty of the patch that by moving the case of the candidate
record's chain as new case "i=0" into the for loop, we also reverse the
order of the two steps in the for-loop body (non blocking freelist alloc
and searching for dead record in a chain) in order to keep the overall
order of execution identical.
Signed-off-by: Michael Adam <[email protected]>
Reviewed-by: Volker Lendecke <[email protected]>
Reviewed-by: Jeremy Allison <[email protected]>
Autobuild-User(master): Michael Adam <[email protected]>
Autobuild-Date(master): Wed Apr 9 10:37:08 CEST 2014 on sn-devel-104
-----------------------------------------------------------------------
Summary of changes:
lib/tdb/common/freelist.c | 26 +++++++++++++-------------
lib/tdb/common/tdb.c | 30 ------------------------------
2 files changed, 13 insertions(+), 43 deletions(-)
Changeset truncated at 500 lines:
diff --git a/lib/tdb/common/freelist.c b/lib/tdb/common/freelist.c
index 6f8f812..2aeeb1c 100644
--- a/lib/tdb/common/freelist.c
+++ b/lib/tdb/common/freelist.c
@@ -404,22 +404,10 @@ tdb_off_t tdb_allocate(struct tdb_context *tdb, int hash,
tdb_len_t length,
* hash chains, something which is pretty bad normally)
*/
- for (i=1; i<tdb->hash_size; i++) {
+ for (i=0; i<tdb->hash_size; i++) {
int list;
- if (tdb_lock_nonblock(tdb, -1, F_WRLCK) == 0) {
- /*
- * Under the freelist lock take the chance to give
- * back our dead records.
- */
- tdb_purge_dead(tdb, hash);
-
- ret = tdb_allocate_from_freelist(tdb, length, rec);
- tdb_unlock(tdb, -1, F_WRLCK);
- return ret;
- }
-
list = BUCKET(hash+i);
if (tdb_lock_nonblock(tdb, list, F_WRLCK) == 0) {
@@ -432,6 +420,18 @@ tdb_off_t tdb_allocate(struct tdb_context *tdb, int hash,
tdb_len_t length,
return ret;
}
}
+
+ if (tdb_lock_nonblock(tdb, -1, F_WRLCK) == 0) {
+ /*
+ * Under the freelist lock take the chance to give
+ * back our dead records.
+ */
+ tdb_purge_dead(tdb, hash);
+
+ ret = tdb_allocate_from_freelist(tdb, length, rec);
+ tdb_unlock(tdb, -1, F_WRLCK);
+ return ret;
+ }
}
blocking_freelist_allocate:
diff --git a/lib/tdb/common/tdb.c b/lib/tdb/common/tdb.c
index ba1c98e..ebd4ffe 100644
--- a/lib/tdb/common/tdb.c
+++ b/lib/tdb/common/tdb.c
@@ -520,36 +520,6 @@ static int _tdb_store(struct tdb_context *tdb, TDB_DATA
key,
if (flag != TDB_INSERT)
tdb_delete_hash(tdb, key, hash);
- if (tdb->max_dead_records != 0) {
- tdb_off_t last_ptr;
- /*
- * Allow for some dead records per hash chain, look if we can
- * find one that can hold the new record. We need enough space
- * for key, data and tailer. If we find one, we don't have to
- * consult the central freelist.
- */
- rec_ptr = tdb_find_dead(tdb, hash, &rec,
- key.dsize + dbuf.dsize,
- &last_ptr);
-
- if (rec_ptr != 0) {
- rec.key_len = key.dsize;
- rec.data_len = dbuf.dsize;
- rec.full_hash = hash;
- rec.magic = TDB_MAGIC;
- if (tdb_rec_write(tdb, rec_ptr, &rec) == -1
- || tdb->methods->tdb_write(
- tdb, rec_ptr + sizeof(rec),
- key.dptr, key.dsize) == -1
- || tdb->methods->tdb_write(
- tdb, rec_ptr + sizeof(rec) + key.dsize,
- dbuf.dptr, dbuf.dsize) == -1) {
- goto fail;
- }
- goto done;
- }
- }
-
/* we have to allocate some space */
rec_ptr = tdb_allocate(tdb, hash, key.dsize + dbuf.dsize, &rec);
--
Samba Shared Repository
