s3:locking: convert share_mode_lock.c to generate_unique_u64()

Instead of a sequence number that gets incremented we just
need a value that's not reused.

The is a similar change like the commit before at the g_lock.c
layer.

I expect a similar performance improvement here, but
I don't know a specific benchmark test to check.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>

diff --git a/source3/librpc/idl/open_files.idl b/source3/librpc/idl/open_files.idl
index 432c1e71bc007463cdfe23716f21191539441571..891ff1f763d68fbb6fd49bbf0377df6de9219030 100644 (file)
--- a/source3/librpc/idl/open_files.idl
+++ b/source3/librpc/idl/open_files.idl
@@ -53,7 +53,7 @@ interface open_files
        } share_mode_flags;
 
        typedef [public] struct {
-               hyper sequence_number;
+               hyper unique_content_epoch;
                share_mode_flags flags;
                [string,charset(UTF8)] char *servicepath;
                [string,charset(UTF8)] char *base_name;

diff --git a/source3/locking/share_mode_lock.c b/source3/locking/share_mode_lock.c
index a93141304b265daeb8d4d87674ae7985ed528e21..ba0bc2b1e7b6a40ff0cb67edb387faaa761f7d8a 100644 (file)
--- a/source3/locking/share_mode_lock.c
+++ b/source3/locking/share_mode_lock.c
@@ -161,9 +161,9 @@ static void share_mode_memcache_store(struct share_mode_data *d)
        const DATA_BLOB key = memcache_key(&d->id);
        struct file_id_buf idbuf;
 
-       DBG_DEBUG("stored entry for file %s seq %"PRIx64" key %s\n",
+       DBG_DEBUG("stored entry for file %s epoch %"PRIx64" key %s\n",
                  d->base_name,
-                 d->sequence_number,
+                 d->unique_content_epoch,
                  file_id_str_buf(d->id, &idbuf));
 
        /* Ensure everything stored in the cache is pristine. */
@@ -193,13 +193,13 @@ static void share_mode_memcache_store(struct share_mode_data *d)
  */
 
 static enum ndr_err_code get_share_mode_blob_header(
-       const uint8_t *buf, size_t buflen, uint64_t *pseq, uint16_t *pflags)
+       const uint8_t *buf, size_t buflen, uint64_t *pepoch, uint16_t *pflags)
 {
        struct ndr_pull ndr = {
                .data = discard_const_p(uint8_t, buf),
                .data_size = buflen,
        };
-       NDR_CHECK(ndr_pull_hyper(&ndr, NDR_SCALARS, pseq));
+       NDR_CHECK(ndr_pull_hyper(&ndr, NDR_SCALARS, pepoch));
        NDR_CHECK(ndr_pull_uint16(&ndr, NDR_SCALARS, pflags));
        return NDR_ERR_SUCCESS;
 }
@@ -278,7 +278,7 @@ static struct share_mode_data *share_mode_memcache_fetch(
 {
        enum ndr_err_code ndr_err;
        struct share_mode_data *d;
-       uint64_t sequence_number;
+       uint64_t unique_content_epoch;
        uint16_t flags;
        void *ptr;
        struct file_id id;
@@ -303,7 +303,7 @@ static struct share_mode_data *share_mode_memcache_fetch(
        }
        /* sequence number key is at start of blob. */
        ndr_err = get_share_mode_blob_header(
-               buf, buflen, &sequence_number, &flags);
+               buf, buflen, &unique_content_epoch, &flags);
        if (ndr_err != NDR_ERR_SUCCESS) {
                /* Bad blob. Remove entry. */
                DBG_DEBUG("bad blob %u key %s\n",
@@ -316,11 +316,11 @@ static struct share_mode_data *share_mode_memcache_fetch(
        }
 
        d = (struct share_mode_data *)ptr;
-       if (d->sequence_number != sequence_number) {
-               DBG_DEBUG("seq changed (cached %"PRIx64") (new %"PRIx64") "
+       if (d->unique_content_epoch != unique_content_epoch) {
+               DBG_DEBUG("epoch changed (cached %"PRIx64") (new %"PRIx64") "
                          "for key %s\n",
-                         d->sequence_number,
-                         sequence_number,
+                         d->unique_content_epoch,
+                         unique_content_epoch,
                          file_id_str_buf(id, &idbuf));
                /* Cache out of date. Remove entry. */
                memcache_delete(NULL,
@@ -346,9 +346,9 @@ static struct share_mode_data *share_mode_memcache_fetch(
        /* And reset the destructor to none. */
        talloc_set_destructor(d, NULL);
 
-       DBG_DEBUG("fetched entry for file %s seq %"PRIx64" key %s\n",
+       DBG_DEBUG("fetched entry for file %s epoch %"PRIx64" key %s\n",
                  d->base_name,
-                 d->sequence_number,
+                 d->unique_content_epoch,
                  file_id_str_buf(id, &idbuf));
 
        return d;
@@ -662,7 +662,7 @@ static NTSTATUS share_mode_data_store(struct share_mode_data *d)
                NDR_PRINT_DEBUG(share_mode_data, d);
        }
 
-       d->sequence_number += 1;
+       d->unique_content_epoch = generate_unique_u64(d->unique_content_epoch);
 
        status = locking_tdb_data_fetch(key, d, &ltdb);
        if (!NT_STATUS_IS_OK(status)) {
@@ -714,8 +714,7 @@ static struct share_mode_data *fresh_share_mode_lock(
        if (d == NULL) {
                goto fail;
        }
-       /* New record - new sequence number. */
-       generate_random_buffer((uint8_t *)&d->sequence_number, 8);
+       d->unique_content_epoch = generate_unique_u64(0);
 
        d->base_name = talloc_strdup(d, smb_fname->base_name);
        if (d->base_name == NULL) {