[SCM] Samba Shared Repository - branch master updated
Andreas Schneider
asn at samba.org
Tue Oct 1 14:23:01 UTC 2024
The branch, master has been updated
via af011b987a4 s3:notifyd: Use a watcher per db record
from 2c91e81ce6d s3:winbindd: let store_current_dc_in_gencache() take the dcaddr directly
https://git.samba.org/?p=samba.git;a=shortlog;h=master
- Log -----------------------------------------------------------------
commit af011b987a4ad0d3753d83cc0b8d97ad64ba874a
Author: Andreas Schneider <asn at samba.org>
Date: Mon Jul 22 12:26:55 2024 +0200
s3:notifyd: Use a watcher per db record
This fixes a O(n²) performance regression in notifyd. The problem was
that we had a watcher per notify instance. This changes the code to have
a watcher per notify db entry.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=14430
Signed-off-by: Andreas Schneider <asn at samba.org>
Reviewed-by: Stefan Metzmacher <metze at samba.org>
Autobuild-User(master): Andreas Schneider <asn at cryptomilk.org>
Autobuild-Date(master): Tue Oct 1 14:22:43 UTC 2024 on atb-devel-224
-----------------------------------------------------------------------
Summary of changes:
source3/smbd/notifyd/notifyd.c | 214 +++++++++++++++++++++++----------
source3/smbd/notifyd/notifyd_db.c | 5 +-
source3/smbd/notifyd/notifyd_entry.c | 51 ++++++--
source3/smbd/notifyd/notifyd_private.h | 46 ++++---
4 files changed, 228 insertions(+), 88 deletions(-)
Changeset truncated at 500 lines:
diff --git a/source3/smbd/notifyd/notifyd.c b/source3/smbd/notifyd/notifyd.c
index 64dd26a7e11..0b07ab3e435 100644
--- a/source3/smbd/notifyd/notifyd.c
+++ b/source3/smbd/notifyd/notifyd.c
@@ -337,6 +337,7 @@ static bool notifyd_apply_rec_change(
struct messaging_context *msg_ctx)
{
struct db_record *rec = NULL;
+ struct notifyd_watcher watcher = {};
struct notifyd_instance *instances = NULL;
size_t num_instances;
size_t i;
@@ -344,6 +345,7 @@ static bool notifyd_apply_rec_change(
TDB_DATA value;
NTSTATUS status;
bool ok = false;
+ bool new_watcher = false;
if (pathlen == 0) {
DBG_WARNING("pathlen==0\n");
@@ -374,8 +376,12 @@ static bool notifyd_apply_rec_change(
value = dbwrap_record_get_value(rec);
if (value.dsize != 0) {
- if (!notifyd_parse_entry(value.dptr, value.dsize, NULL,
- &num_instances)) {
+ ok = notifyd_parse_entry(value.dptr,
+ value.dsize,
+ &watcher,
+ NULL,
+ &num_instances);
+ if (!ok) {
goto fail;
}
}
@@ -390,8 +396,22 @@ static bool notifyd_apply_rec_change(
goto fail;
}
- if (value.dsize != 0) {
- memcpy(instances, value.dptr, value.dsize);
+ if (num_instances > 0) {
+ struct notifyd_instance *tmp = NULL;
+ size_t num_tmp = 0;
+
+ ok = notifyd_parse_entry(value.dptr,
+ value.dsize,
+ NULL,
+ &tmp,
+ &num_tmp);
+ if (!ok) {
+ goto fail;
+ }
+
+ memcpy(instances,
+ tmp,
+ sizeof(struct notifyd_instance) * num_tmp);
}
for (i=0; i<num_instances; i++) {
@@ -414,41 +434,106 @@ static bool notifyd_apply_rec_change(
*instance = (struct notifyd_instance) {
.client = *client,
.instance = *chg,
- .internal_filter = chg->filter,
- .internal_subdir_filter = chg->subdir_filter
};
num_instances += 1;
}
- if ((instance->instance.filter != 0) ||
- (instance->instance.subdir_filter != 0)) {
- int ret;
+ /*
+ * Calculate an intersection of the instances filters for the watcher.
+ */
+ if (instance->instance.filter > 0) {
+ uint32_t filter = instance->instance.filter;
+
+ if ((watcher.filter & filter) != filter) {
+ watcher.filter |= filter;
+
+ new_watcher = true;
+ }
+ }
+
+ /*
+ * Calculate an intersection of the instances subdir_filters for the
+ * watcher.
+ */
+ if (instance->instance.subdir_filter > 0) {
+ uint32_t subdir_filter = instance->instance.subdir_filter;
- TALLOC_FREE(instance->sys_watch);
+ if ((watcher.subdir_filter & subdir_filter) != subdir_filter) {
+ watcher.subdir_filter |= subdir_filter;
- ret = sys_notify_watch(entries, sys_notify_ctx, path,
- &instance->internal_filter,
- &instance->internal_subdir_filter,
- notifyd_sys_callback, msg_ctx,
- &instance->sys_watch);
- if (ret != 0) {
- DBG_WARNING("sys_notify_watch for [%s] returned %s\n",
- path, strerror(errno));
+ new_watcher = true;
}
}
if ((instance->instance.filter == 0) &&
(instance->instance.subdir_filter == 0)) {
+ uint32_t tmp_filter = 0;
+ uint32_t tmp_subdir_filter = 0;
+
/* This is a delete request */
- TALLOC_FREE(instance->sys_watch);
*instance = instances[num_instances-1];
num_instances -= 1;
+
+ for (i = 0; i < num_instances; i++) {
+ struct notifyd_instance *tmp = &instances[i];
+
+ tmp_filter |= tmp->instance.filter;
+ tmp_subdir_filter |= tmp->instance.subdir_filter;
+ }
+
+ /*
+ * If the filter has changed, register a new watcher with the
+ * changed filter.
+ */
+ if (watcher.filter != tmp_filter ||
+ watcher.subdir_filter != tmp_subdir_filter)
+ {
+ watcher.filter = tmp_filter;
+ watcher.subdir_filter = tmp_subdir_filter;
+
+ new_watcher = true;
+ }
+ }
+
+ if (new_watcher) {
+ /*
+ * In case we removed all notify instances, we want to remove
+ * the watcher. We won't register a new one, if no filters are
+ * set anymore.
+ */
+
+ TALLOC_FREE(watcher.sys_watch);
+
+ watcher.sys_filter = watcher.filter;
+ watcher.sys_subdir_filter = watcher.subdir_filter;
+
+ /*
+ * Only register a watcher if we have filter.
+ */
+ if (watcher.filter != 0 || watcher.subdir_filter != 0) {
+ int ret = sys_notify_watch(entries,
+ sys_notify_ctx,
+ path,
+ &watcher.sys_filter,
+ &watcher.sys_subdir_filter,
+ notifyd_sys_callback,
+ msg_ctx,
+ &watcher.sys_watch);
+ if (ret != 0) {
+ DBG_WARNING("sys_notify_watch for [%s] "
+ "returned %s\n",
+ path,
+ strerror(errno));
+ }
+ }
}
DBG_DEBUG("%s has %zu instances\n", path, num_instances);
if (num_instances == 0) {
+ TALLOC_FREE(watcher.sys_watch);
+
status = dbwrap_record_delete(rec);
if (!NT_STATUS_IS_OK(status)) {
DBG_WARNING("dbwrap_record_delete returned %s\n",
@@ -456,13 +541,21 @@ static bool notifyd_apply_rec_change(
goto fail;
}
} else {
- value = make_tdb_data(
- (uint8_t *)instances,
- sizeof(struct notifyd_instance) * num_instances);
+ struct TDB_DATA iov[2] = {
+ {
+ .dptr = (uint8_t *)&watcher,
+ .dsize = sizeof(struct notifyd_watcher),
+ },
+ {
+ .dptr = (uint8_t *)instances,
+ .dsize = sizeof(struct notifyd_instance) *
+ num_instances,
+ },
+ };
- status = dbwrap_record_store(rec, value, 0);
+ status = dbwrap_record_storev(rec, iov, ARRAY_SIZE(iov), 0);
if (!NT_STATUS_IS_OK(status)) {
- DBG_WARNING("dbwrap_record_store returned %s\n",
+ DBG_WARNING("dbwrap_record_storev returned %s\n",
nt_errstr(status));
goto fail;
}
@@ -706,12 +799,18 @@ static void notifyd_trigger_parser(TDB_DATA key, TDB_DATA data,
.when = tstate->msg->when };
struct iovec iov[2];
size_t path_len = key.dsize;
+ struct notifyd_watcher watcher = {};
struct notifyd_instance *instances = NULL;
size_t num_instances = 0;
size_t i;
+ bool ok;
- if (!notifyd_parse_entry(data.dptr, data.dsize, &instances,
- &num_instances)) {
+ ok = notifyd_parse_entry(data.dptr,
+ data.dsize,
+ &watcher,
+ &instances,
+ &num_instances);
+ if (!ok) {
DBG_DEBUG("Could not parse notifyd_entry\n");
return;
}
@@ -734,9 +833,11 @@ static void notifyd_trigger_parser(TDB_DATA key, TDB_DATA data,
if (tstate->covered_by_sys_notify) {
if (tstate->recursive) {
- i_filter = instance->internal_subdir_filter;
+ i_filter = watcher.sys_subdir_filter &
+ instance->instance.subdir_filter;
} else {
- i_filter = instance->internal_filter;
+ i_filter = watcher.sys_filter &
+ instance->instance.filter;
}
} else {
if (tstate->recursive) {
@@ -1146,46 +1247,39 @@ static int notifyd_add_proxy_syswatches(struct db_record *rec,
struct db_context *db = dbwrap_record_get_db(rec);
TDB_DATA key = dbwrap_record_get_key(rec);
TDB_DATA value = dbwrap_record_get_value(rec);
- struct notifyd_instance *instances = NULL;
- size_t num_instances = 0;
- size_t i;
+ struct notifyd_watcher watcher = {};
char path[key.dsize+1];
bool ok;
+ int ret;
memcpy(path, key.dptr, key.dsize);
path[key.dsize] = '\0';
- ok = notifyd_parse_entry(value.dptr, value.dsize, &instances,
- &num_instances);
+ /* This is a remote database, we just need the watcher. */
+ ok = notifyd_parse_entry(value.dptr, value.dsize, &watcher, NULL, NULL);
if (!ok) {
DBG_WARNING("Could not parse notifyd entry for %s\n", path);
return 0;
}
- for (i=0; i<num_instances; i++) {
- struct notifyd_instance *instance = &instances[i];
- uint32_t filter = instance->instance.filter;
- uint32_t subdir_filter = instance->instance.subdir_filter;
- int ret;
+ watcher.sys_watch = NULL;
+ watcher.sys_filter = watcher.filter;
+ watcher.sys_subdir_filter = watcher.subdir_filter;
- /*
- * This is a remote database. Pointers that we were
- * given don't make sense locally. Initialize to NULL
- * in case sys_notify_watch fails.
- */
- instances[i].sys_watch = NULL;
-
- ret = state->sys_notify_watch(
- db, state->sys_notify_ctx, path,
- &filter, &subdir_filter,
- notifyd_sys_callback, state->msg_ctx,
- &instance->sys_watch);
- if (ret != 0) {
- DBG_WARNING("inotify_watch returned %s\n",
- strerror(errno));
- }
+ ret = state->sys_notify_watch(db,
+ state->sys_notify_ctx,
+ path,
+ &watcher.filter,
+ &watcher.subdir_filter,
+ notifyd_sys_callback,
+ state->msg_ctx,
+ &watcher.sys_watch);
+ if (ret != 0) {
+ DBG_WARNING("inotify_watch returned %s\n", strerror(errno));
}
+ memcpy(value.dptr, &watcher, sizeof(struct notifyd_watcher));
+
return 0;
}
@@ -1193,21 +1287,17 @@ static int notifyd_db_del_syswatches(struct db_record *rec, void *private_data)
{
TDB_DATA key = dbwrap_record_get_key(rec);
TDB_DATA value = dbwrap_record_get_value(rec);
- struct notifyd_instance *instances = NULL;
- size_t num_instances = 0;
- size_t i;
+ struct notifyd_watcher watcher = {};
bool ok;
- ok = notifyd_parse_entry(value.dptr, value.dsize, &instances,
- &num_instances);
+ ok = notifyd_parse_entry(value.dptr, value.dsize, &watcher, NULL, NULL);
if (!ok) {
DBG_WARNING("Could not parse notifyd entry for %.*s\n",
(int)key.dsize, (char *)key.dptr);
return 0;
}
- for (i=0; i<num_instances; i++) {
- TALLOC_FREE(instances[i].sys_watch);
- }
+ TALLOC_FREE(watcher.sys_watch);
+
return 0;
}
diff --git a/source3/smbd/notifyd/notifyd_db.c b/source3/smbd/notifyd/notifyd_db.c
index 18228619e9a..7dc3cd58081 100644
--- a/source3/smbd/notifyd/notifyd_db.c
+++ b/source3/smbd/notifyd/notifyd_db.c
@@ -40,7 +40,10 @@ static bool notifyd_parse_db_parser(TDB_DATA key, TDB_DATA value,
memcpy(path, key.dptr, key.dsize);
path[key.dsize] = 0;
- ok = notifyd_parse_entry(value.dptr, value.dsize, &instances,
+ ok = notifyd_parse_entry(value.dptr,
+ value.dsize,
+ NULL,
+ &instances,
&num_instances);
if (!ok) {
DBG_DEBUG("Could not parse entry for path %s\n", path);
diff --git a/source3/smbd/notifyd/notifyd_entry.c b/source3/smbd/notifyd/notifyd_entry.c
index 539010de03a..f3b0e908136 100644
--- a/source3/smbd/notifyd/notifyd_entry.c
+++ b/source3/smbd/notifyd/notifyd_entry.c
@@ -21,22 +21,51 @@
* Parse an entry in the notifyd_context->entries database
*/
-bool notifyd_parse_entry(
- uint8_t *buf,
- size_t buflen,
- struct notifyd_instance **instances,
- size_t *num_instances)
+/**
+ * @brief Parse a notifyd database entry.
+ *
+ * The memory we pass down needs to be aligned. If it isn't aligned we can run
+ * into obscure errors as we just point into the data buffer.
+ *
+ * @param data The data to parse
+ * @param data_len The length of the data to parse
+ * @param watcher A pointer to store the watcher data or NULL.
+ * @param instances A pointer to store the array of notify instances or NULL.
+ * @param pnum_instances The number of elements in the array. If you just want
+ * the number of elements pass NULL for the watcher and instances pointers.
+ *
+ * @return true on success, false if an error occurred.
+ */
+bool notifyd_parse_entry(uint8_t *data,
+ size_t data_len,
+ struct notifyd_watcher *watcher,
+ struct notifyd_instance **instances,
+ size_t *pnum_instances)
{
- if ((buflen % sizeof(struct notifyd_instance)) != 0) {
- DBG_WARNING("invalid buffer size: %zu\n", buflen);
+ size_t ilen;
+
+ if (data_len < sizeof(struct notifyd_watcher)) {
return false;
}
- if (instances != NULL) {
- *instances = (struct notifyd_instance *)buf;
+ if (watcher != NULL) {
+ *watcher = *((struct notifyd_watcher *)(uintptr_t)data);
}
- if (num_instances != NULL) {
- *num_instances = buflen / sizeof(struct notifyd_instance);
+
+ ilen = data_len - sizeof(struct notifyd_watcher);
+ if ((ilen % sizeof(struct notifyd_instance)) != 0) {
+ return false;
+ }
+
+ if (pnum_instances != NULL) {
+ *pnum_instances = ilen / sizeof(struct notifyd_instance);
}
+ if (instances != NULL) {
+ /* The (uintptr_t) cast removes a warning from -Wcast-align. */
+ *instances =
+ (struct notifyd_instance *)(uintptr_t)
+ (data + sizeof(struct notifyd_watcher));
+ }
+
return true;
}
diff --git a/source3/smbd/notifyd/notifyd_private.h b/source3/smbd/notifyd/notifyd_private.h
index 36c08f47c54..db8e6e1c005 100644
--- a/source3/smbd/notifyd/notifyd_private.h
+++ b/source3/smbd/notifyd/notifyd_private.h
@@ -20,30 +20,48 @@
#include "lib/util/server_id.h"
#include "notifyd.h"
+
/*
- * notifyd's representation of a notify instance
+ * Representation of a watcher for a path
+ *
+ * This will be stored in the db.
*/
-struct notifyd_instance {
- struct server_id client;
- struct notify_instance instance;
-
- void *sys_watch; /* inotify/fam/etc handle */
+struct notifyd_watcher {
+ /*
+ * This is an intersections of the filter the watcher is listening for.
+ */
+ uint32_t filter;
+ uint32_t subdir_filter;
/*
- * Filters after sys_watch took responsibility of some bits
+ * Those are inout variables passed to the sys_watcher. The sys_watcher
+ * will remove the bits it can't handle.
*/
- uint32_t internal_filter;
- uint32_t internal_subdir_filter;
+ uint32_t sys_filter;
+ uint32_t sys_subdir_filter;
+
+ /* The handle for inotify/fam etc. */
+ void *sys_watch;
+};
+
+/*
+ * Representation of a notifyd instance
+ *
+ * This will be stored in the db.
+ */
+struct notifyd_instance {
+ struct server_id client;
+ struct notify_instance instance;
};
/*
* Parse an entry in the notifyd_context->entries database
*/
-bool notifyd_parse_entry(
- uint8_t *buf,
- size_t buflen,
- struct notifyd_instance **instances,
- size_t *num_instances);
+bool notifyd_parse_entry(uint8_t *data,
+ size_t data_len,
+ struct notifyd_watcher *watcher,
+ struct notifyd_instance **instances,
+ size_t *num_instances);
#endif
--
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