* 2. Once the locks are obtained, signal parent process via fd.
* 3. Invoke registered callback routine with locking status.
* 4. If the child process cannot get locks within certain time,
- * diagnose using /proc/locks and log warning message
+ * execute an external script to debug.
*
* ctdb_lock_record() - get a lock on a record
* ctdb_lock_db() - get a lock on a DB
* auto_mark - whether to mark/unmark DBs in before/after callback
*/
-/* FIXME: Add a tunable max_lock_processes_per_db */
-#define MAX_LOCK_PROCESSES_PER_DB (100)
-
enum lock_type {
LOCK_RECORD,
LOCK_DB,
TDB_DATA key;
uint32_t priority;
bool auto_mark;
- struct lock_request *req_queue;
+ struct lock_request *request;
pid_t child;
int fd[2];
struct tevent_fd *tfd;
struct tevent_timer *ttimer;
struct timeval start_time;
uint32_t key_hash;
+ bool can_schedule;
};
/* lock_request is the client specific part for a lock request */
struct lock_request {
- struct lock_request *next, *prev;
struct lock_context *lctx;
void (*callback)(void *, bool);
void *private_data;
lock_ctx->ctdb_db->lock_num_current--;
}
CTDB_DECREMENT_STAT(lock_ctx->ctdb, locks.num_current);
- if (lock_ctx->type == LOCK_RECORD || lock_ctx->type == LOCK_DB) {
+ if (lock_ctx->ctdb_db) {
CTDB_DECREMENT_DB_STAT(lock_ctx->ctdb_db, locks.num_current);
}
} else {
DLIST_REMOVE(lock_ctx->ctdb->lock_pending, lock_ctx);
- lock_ctx->ctdb->lock_num_pending--;
CTDB_DECREMENT_STAT(lock_ctx->ctdb, locks.num_pending);
- if (lock_ctx->type == LOCK_RECORD || lock_ctx->type == LOCK_DB) {
+ if (lock_ctx->ctdb_db) {
CTDB_DECREMENT_DB_STAT(lock_ctx->ctdb_db, locks.num_pending);
}
}
*/
static int ctdb_lock_request_destructor(struct lock_request *lock_request)
{
- DLIST_REMOVE(lock_request->lctx->req_queue, lock_request);
+ lock_request->lctx->request = NULL;
return 0;
}
-
void ctdb_lock_free_request_context(struct lock_request *lock_req)
{
struct lock_context *lock_ctx;
*/
static void process_callbacks(struct lock_context *lock_ctx, bool locked)
{
- struct lock_request *request, *next;
+ struct lock_request *request;
if (lock_ctx->auto_mark && locked) {
switch (lock_ctx->type) {
}
}
- /* Iterate through all callbacks */
- request = lock_ctx->req_queue;
- while (request) {
- if (lock_ctx->auto_mark) {
- /* Reset the destructor, so request is not removed from the list */
- talloc_set_destructor(request, NULL);
- }
-
- /* In case, callback frees the request, store next */
- next = request->next;
- request->callback(request->private_data, locked);
- request = next;
+ request = lock_ctx->request;
+ if (lock_ctx->auto_mark) {
+ /* Reset the destructor, so request is not removed from the list */
+ talloc_set_destructor(request, NULL);
}
+ request->callback(request->private_data, locked);
if (lock_ctx->auto_mark && locked) {
switch (lock_ctx->type) {
}
/* Update statistics */
- CTDB_DECREMENT_STAT(lock_ctx->ctdb, locks.num_pending);
CTDB_INCREMENT_STAT(lock_ctx->ctdb, locks.num_calls);
if (lock_ctx->ctdb_db) {
- CTDB_DECREMENT_DB_STAT(lock_ctx->ctdb_db, locks.num_pending);
CTDB_INCREMENT_DB_STAT(lock_ctx->ctdb_db, locks.num_calls);
}
lock_ctx = talloc_get_type_abort(private_data, struct lock_context);
ctdb = lock_ctx->ctdb;
- if (lock_ctx->type == LOCK_RECORD || lock_ctx->type == LOCK_DB) {
+ if (lock_ctx->ctdb_db) {
DEBUG(DEBUG_WARNING,
("Unable to get %s lock on database %s for %.0lf seconds\n",
(lock_ctx->type == LOCK_RECORD ? "RECORD" : "DB"),
}
-/*
- * Find the lock context of a given type
- */
-static struct lock_context *find_lock_context(struct lock_context *lock_list,
- struct ctdb_db_context *ctdb_db,
- TDB_DATA key,
- uint32_t priority,
- enum lock_type type,
- uint32_t key_hash)
-{
- struct lock_context *lock_ctx;
-
- /* Search active locks */
- for (lock_ctx=lock_list; lock_ctx; lock_ctx=lock_ctx->next) {
- if (lock_ctx->type != type) {
- continue;
- }
-
- switch (lock_ctx->type) {
- case LOCK_RECORD:
- if (ctdb_db == lock_ctx->ctdb_db &&
- key_hash == lock_ctx->key_hash) {
- goto done;
- }
- break;
-
- case LOCK_DB:
- if (ctdb_db == lock_ctx->ctdb_db) {
- goto done;
- }
- break;
-
- case LOCK_ALLDB_PRIO:
- if (priority == lock_ctx->priority) {
- goto done;
- }
- break;
-
- case LOCK_ALLDB:
- goto done;
- break;
- }
- }
-
- /* Did not find the lock context we are searching for */
- lock_ctx = NULL;
-
-done:
- return lock_ctx;
-
-}
-
-
/*
* Schedule a new lock child process
* Set up callback handler and timeout handler
*/
static void ctdb_lock_schedule(struct ctdb_context *ctdb)
{
- struct lock_context *lock_ctx, *next_ctx, *active_ctx;
+ struct lock_context *lock_ctx, *next_ctx;
int ret;
TALLOC_CTX *tmp_ctx;
const char *helper = BINDIR "/ctdb_lock_helper";
lock_ctx = ctdb->lock_pending;
while (lock_ctx != NULL) {
next_ctx = lock_ctx->next;
- if (! lock_ctx->req_queue) {
- DEBUG(DEBUG_INFO, ("Removing lock context without lock requests\n"));
+ if (! lock_ctx->request) {
+ DEBUG(DEBUG_INFO, ("Removing lock context without lock request\n"));
DLIST_REMOVE(ctdb->lock_pending, lock_ctx);
- ctdb->lock_num_pending--;
CTDB_DECREMENT_STAT(ctdb, locks.num_pending);
if (lock_ctx->ctdb_db) {
CTDB_DECREMENT_DB_STAT(lock_ctx->ctdb_db, locks.num_pending);
}
talloc_free(lock_ctx);
} else {
- active_ctx = find_lock_context(ctdb->lock_current, lock_ctx->ctdb_db,
- lock_ctx->key, lock_ctx->priority,
- lock_ctx->type, lock_ctx->key_hash);
- if (active_ctx == NULL) {
- if (lock_ctx->ctdb_db == NULL ||
- lock_ctx->ctdb_db->lock_num_current < MAX_LOCK_PROCESSES_PER_DB) {
- /* Found a lock context with lock requests */
- break;
- }
+ if (lock_ctx->ctdb_db == NULL ||
+ lock_ctx->ctdb_db->lock_num_current < ctdb->tunable.lock_processes_per_db) {
+ /* Found a lock context with lock requests */
+ break;
}
-
- /* There is already a child waiting for the
- * same key. So don't schedule another child
- * just yet.
- */
}
lock_ctx = next_ctx;
}
/* Move the context from pending to current */
DLIST_REMOVE(ctdb->lock_pending, lock_ctx);
- ctdb->lock_num_pending--;
DLIST_ADD_END(ctdb->lock_current, lock_ctx, NULL);
+ CTDB_DECREMENT_STAT(lock_ctx->ctdb, locks.num_pending);
+ CTDB_INCREMENT_STAT(lock_ctx->ctdb, locks.num_current);
if (lock_ctx->ctdb_db) {
lock_ctx->ctdb_db->lock_num_current++;
- CTDB_INCREMENT_STAT(lock_ctx->ctdb, locks.num_current);
+ CTDB_DECREMENT_DB_STAT(lock_ctx->ctdb_db, locks.num_pending);
CTDB_INCREMENT_DB_STAT(lock_ctx->ctdb_db, locks.num_current);
}
}
return NULL;
}
-#if 0
- /* Disable this optimization to ensure first-in-first-out fair
- * scheduling of lock requests */
+ lock_ctx = talloc_zero(ctdb, struct lock_context);
+ if (lock_ctx == NULL) {
+ DEBUG(DEBUG_ERR, ("Failed to create a new lock context\n"));
+ return NULL;
+ }
- /* get a context for this key - search only the pending contexts,
- * current contexts might in the middle of processing callbacks */
- lock_ctx = find_lock_context(ctdb->lock_pending, ctdb_db, key, priority, type);
-#endif
+ if ((request = talloc_zero(lock_ctx, struct lock_request)) == NULL) {
+ talloc_free(lock_ctx);
+ return NULL;
+ }
- /* No existing context, create one */
- if (lock_ctx == NULL) {
- lock_ctx = talloc_zero(ctdb, struct lock_context);
- if (lock_ctx == NULL) {
- DEBUG(DEBUG_ERR, ("Failed to create a new lock context\n"));
+ lock_ctx->type = type;
+ lock_ctx->ctdb = ctdb;
+ lock_ctx->ctdb_db = ctdb_db;
+ lock_ctx->key.dsize = key.dsize;
+ if (key.dsize > 0) {
+ lock_ctx->key.dptr = talloc_memdup(lock_ctx, key.dptr, key.dsize);
+ if (lock_ctx->key.dptr == NULL) {
+ DEBUG(DEBUG_ERR, (__location__ "Memory allocation error\n"));
+ talloc_free(lock_ctx);
return NULL;
}
+ lock_ctx->key_hash = ctdb_hash(&key);
+ } else {
+ lock_ctx->key.dptr = NULL;
+ }
+ lock_ctx->priority = priority;
+ lock_ctx->auto_mark = auto_mark;
- lock_ctx->type = type;
- lock_ctx->ctdb = ctdb;
- lock_ctx->ctdb_db = ctdb_db;
- lock_ctx->key.dsize = key.dsize;
- if (key.dsize > 0) {
- lock_ctx->key.dptr = talloc_memdup(lock_ctx, key.dptr, key.dsize);
- if (lock_ctx->key.dptr == NULL) {
- DEBUG(DEBUG_ERR, (__location__ "Memory allocation error\n"));
- talloc_free(lock_ctx);
- return NULL;
- }
- lock_ctx->key_hash = ctdb_hash(&key);
- } else {
- lock_ctx->key.dptr = NULL;
- }
- lock_ctx->priority = priority;
- lock_ctx->auto_mark = auto_mark;
-
- lock_ctx->child = -1;
+ lock_ctx->request = request;
+ lock_ctx->child = -1;
+ /* Non-record locks are required by recovery and should be scheduled
+ * immediately, so keep them at the head of the pending queue.
+ */
+ if (lock_ctx->type == LOCK_RECORD) {
DLIST_ADD_END(ctdb->lock_pending, lock_ctx, NULL);
- ctdb->lock_num_pending++;
- CTDB_INCREMENT_STAT(ctdb, locks.num_pending);
- if (ctdb_db) {
- CTDB_INCREMENT_DB_STAT(ctdb_db, locks.num_pending);
- }
-
- /* Start the timer when we activate the context */
- lock_ctx->start_time = timeval_current();
+ } else {
+ DLIST_ADD(ctdb->lock_pending, lock_ctx);
}
-
- if ((request = talloc_zero(lock_ctx, struct lock_request)) == NULL) {
- talloc_free(lock_ctx);
- return NULL;
+ CTDB_INCREMENT_STAT(ctdb, locks.num_pending);
+ if (ctdb_db) {
+ CTDB_INCREMENT_DB_STAT(ctdb_db, locks.num_pending);
}
+ /* Start the timer when we activate the context */
+ lock_ctx->start_time = timeval_current();
+
request->lctx = lock_ctx;
request->callback = callback;
request->private_data = private_data;
talloc_set_destructor(request, ctdb_lock_request_destructor);
- DLIST_ADD_END(lock_ctx->req_queue, request, NULL);
ctdb_lock_schedule(ctdb);
git.samba.org / obnox / samba / samba-obnox.git / blobdiff