/*
* (C) 2001 Clemson University and The University of Chicago
* (C) 2011 Omnibond Systems
*
* Changes by Acxiom Corporation to implement generic service_operation()
* function, Copyright Acxiom Corporation, 2005.
*
* See COPYING in top-level directory.
*/
/*
* In-kernel waitqueue operations.
*/
#include "protocol.h"
#include "orangefs-kernel.h"
#include "orangefs-bufmap.h"
static int wait_for_cancellation_downcall(struct orangefs_kernel_op_s *);
static int wait_for_matching_downcall(struct orangefs_kernel_op_s *);
/*
* What we do in this function is to walk the list of operations that are
* present in the request queue and mark them as purged.
* NOTE: This is called from the device close after client-core has
* guaranteed that no new operations could appear on the list since the
* client-core is anyway going to exit.
*/
void purge_waiting_ops(void)
{
struct orangefs_kernel_op_s *op;
spin_lock(&orangefs_request_list_lock);
list_for_each_entry(op, &orangefs_request_list, list) {
gossip_debug(GOSSIP_WAIT_DEBUG,
"pvfs2-client-core: purging op tag %llu %s\n",
llu(op->tag),
get_opname_string(op));
spin_lock(&op->lock);
set_op_state_purged(op);
spin_unlock(&op->lock);
}
spin_unlock(&orangefs_request_list_lock);
}
static inline void
add_op_to_request_list(struct orangefs_kernel_op_s *op)
{
spin_lock(&orangefs_request_list_lock);
spin_lock(&op->lock);
set_op_state_waiting(op);
list_add_tail(&op->list, &orangefs_request_list);
spin_unlock(&orangefs_request_list_lock);
spin_unlock(&op->lock);
wake_up_interruptible(&orangefs_request_list_waitq);
}
static inline
void add_priority_op_to_request_list(struct orangefs_kernel_op_s *op)
{
spin_lock(&orangefs_request_list_lock);
spin_lock(&op->lock);
set_op_state_waiting(op);
list_add(&op->list, &orangefs_request_list);
spin_unlock(&orangefs_request_list_lock);
spin_unlock(&op->lock);
wake_up_interruptible(&orangefs_request_list_waitq);
}
/*
* submits a ORANGEFS operation and waits for it to complete
*
* Note op->downcall.status will contain the status of the operation (in
* errno format), whether provided by pvfs2-client or a result of failure to
* service the operation. If the caller wishes to distinguish, then
* op->state can be checked to see if it was serviced or not.
*
* Returns contents of op->downcall.status for convenience
*/
int service_operation(struct orangefs_kernel_op_s *op,
const char *op_name,
int flags)
{
/* flags to modify behavior */
sigset_t orig_sigset;
int ret = 0;
DEFINE_WAIT(wait_entry);
op->upcall.tgid = current->tgid;
op->upcall.pid = current->pid;
retry_servicing:
op->downcall.status = 0;
gossip_debug(GOSSIP_WAIT_DEBUG,
"orangefs: service_operation: %s %p\n",
op_name,
op);
gossip_debug(GOSSIP_WAIT_DEBUG,
"orangefs: operation posted by process: %s, pid: %i\n",
current->comm,
current->pid);
/* mask out signals if this operation is not to be interrupted */
if (!(flags & ORANGEFS_OP_INTERRUPTIBLE))
orangefs_block_signals(&orig_sigset);
if (!(flags & ORANGEFS_OP_NO_SEMAPHORE)) {
ret = mutex_lock_interruptible(&request_mutex);
/*
* check to see if we were interrupted while waiting for
* semaphore
*/
if (ret < 0) {
if (!(flags & ORANGEFS_OP_INTERRUPTIBLE))
orangefs_set_signals(&orig_sigset);
op->downcall.status = ret;
gossip_debug(GOSSIP_WAIT_DEBUG,
"orangefs: service_operation interrupted.\n");
return ret;
}
}
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s:About to call is_daemon_in_service().\n",
__func__);
if (is_daemon_in_service() < 0) {
/*
* By incrementing the per-operation attempt counter, we
* directly go into the timeout logic while waiting for
* the matching downcall to be read
*/
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s:client core is NOT in service(%d).\n",
__func__,
is_daemon_in_service());
op->attempts++;
}
/* queue up the operation */
if (flags & ORANGEFS_OP_PRIORITY) {
add_priority_op_to_request_list(op);
} else {
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s:About to call add_op_to_request_list().\n",
__func__);
add_op_to_request_list(op);
}
if (!(flags & ORANGEFS_OP_NO_SEMAPHORE))
mutex_unlock(&request_mutex);
/*
* If we are asked to service an asynchronous operation from
* VFS perspective, we are done.
*/
if (flags & ORANGEFS_OP_ASYNC)
return 0;
if (flags & ORANGEFS_OP_CANCELLATION) {
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s:"
"About to call wait_for_cancellation_downcall.\n",
__func__);
ret = wait_for_cancellation_downcall(op);
} else {
ret = wait_for_matching_downcall(op);
}
if (ret < 0) {
/* failed to get matching downcall */
if (ret == -ETIMEDOUT) {
gossip_err("orangefs: %s -- wait timed out; aborting attempt.\n",
op_name);
}
op->downcall.status = ret;
} else {
/* got matching downcall; make sure status is in errno format */
op->downcall.status =
orangefs_normalize_to_errno(op->downcall.status);
ret = op->downcall.status;
}
if (!(flags & ORANGEFS_OP_INTERRUPTIBLE))
orangefs_set_signals(&orig_sigset);
BUG_ON(ret != op->downcall.status);
/* retry if operation has not been serviced and if requested */
if (!op_state_serviced(op) && op->downcall.status == -EAGAIN) {
gossip_debug(GOSSIP_WAIT_DEBUG,
"orangefs: tag %llu (%s)"
" -- operation to be retried (%d attempt)\n",
llu(op->tag),
op_name,
op->attempts + 1);
if (!op->uses_shared_memory)
/*
* this operation doesn't use the shared memory
* system
*/
goto retry_servicing;
/* op uses shared memory */
if (orangefs_get_bufmap_init() == 0) {
WARN_ON(1);
/*
* This operation uses the shared memory system AND
* the system is not yet ready. This situation occurs
* when the client-core is restarted AND there were
* operations waiting to be processed or were already
* in process.
*/
gossip_debug(GOSSIP_WAIT_DEBUG,
"uses_shared_memory is true.\n");
gossip_debug(GOSSIP_WAIT_DEBUG,
"Client core in-service status(%d).\n",
is_daemon_in_service());
gossip_debug(GOSSIP_WAIT_DEBUG, "bufmap_init:%d.\n",
orangefs_get_bufmap_init());
gossip_debug(GOSSIP_WAIT_DEBUG,
"operation's status is 0x%0x.\n",
op->op_state);
/*
* let process sleep for a few seconds so shared
* memory system can be initialized.
*/
prepare_to_wait(&orangefs_bufmap_init_waitq,
&wait_entry,
TASK_INTERRUPTIBLE);
/*
* Wait for orangefs_bufmap_initialize() to wake me up
* within the allotted time.
*/
ret = schedule_timeout(
ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS * HZ);
gossip_debug(GOSSIP_WAIT_DEBUG,
"Value returned from schedule_timeout:"
"%d.\n",
ret);
gossip_debug(GOSSIP_WAIT_DEBUG,
"Is shared memory available? (%d).\n",
orangefs_get_bufmap_init());
finish_wait(&orangefs_bufmap_init_waitq, &wait_entry);
if (orangefs_get_bufmap_init() == 0) {
gossip_err("%s:The shared memory system has not started in %d seconds after the client core restarted. Aborting user's request(%s).\n",
__func__,
ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS,
get_opname_string(op));
return -EIO;
}
/*
* Return to the calling function and re-populate a
* shared memory buffer.
*/
return -EAGAIN;
}
}
gossip_debug(GOSSIP_WAIT_DEBUG,
"orangefs: service_operation %s returning: %d for %p.\n",
op_name,
ret,
op);
return ret;
}
static void orangefs_clean_up_interrupted_operation(struct orangefs_kernel_op_s *op)
{
/*
* handle interrupted cases depending on what state we were in when
* the interruption is detected. there is a coarse grained lock
* across the operation.
*
* Called with op->lock held.
*/
op->op_state |= OP_VFS_STATE_GIVEN_UP;
if (op_state_waiting(op)) {
/*
* upcall hasn't been read; remove op from upcall request
* list.
*/
spin_unlock(&op->lock);
spin_lock(&orangefs_request_list_lock);
list_del(&op->list);
spin_unlock(&orangefs_request_list_lock);
gossip_debug(GOSSIP_WAIT_DEBUG,
"Interrupted: Removed op %p from request_list\n",
op);
} else if (op_state_in_progress(op)) {
/* op must be removed from the in progress htable */
spin_unlock(&op->lock);
spin_lock(&htable_ops_in_progress_lock);
list_del(&op->list);
spin_unlock(&htable_ops_in_progress_lock);
gossip_debug(GOSSIP_WAIT_DEBUG,
"Interrupted: Removed op %p"
" from htable_ops_in_progress\n",
op);
} else if (!op_state_serviced(op)) {
spin_unlock(&op->lock);
gossip_err("interrupted operation is in a weird state 0x%x\n",
op->op_state);
} else {
/*
* It is not intended for execution to flow here,
* but having this unlock here makes sparse happy.
*/
gossip_err("%s: can't get here.\n", __func__);
spin_unlock(&op->lock);
}
}
/*
* sleeps on waitqueue waiting for matching downcall.
* if client-core finishes servicing, then we are good to go.
* else if client-core exits, we get woken up here, and retry with a timeout
*
* Post when this call returns to the caller, the specified op will no
* longer be on any list or htable.
*
* Returns 0 on success and -errno on failure
* Errors are:
* EAGAIN in case we want the caller to requeue and try again..
* EINTR/EIO/ETIMEDOUT indicating we are done trying to service this
* operation since client-core seems to be exiting too often
* or if we were interrupted.
*/
static int wait_for_matching_downcall(struct orangefs_kernel_op_s *op)
{
int ret = -EINVAL;
DEFINE_WAIT(wait_entry);
while (1) {
spin_lock(&op->lock);
prepare_to_wait(&op->waitq, &wait_entry, TASK_INTERRUPTIBLE);
if (op_state_serviced(op)) {
spin_unlock(&op->lock);
ret = 0;
break;
}
if (unlikely(signal_pending(current))) {
gossip_debug(GOSSIP_WAIT_DEBUG,
"*** %s:"
" operation interrupted by a signal (tag "
"%llu, op %p)\n",
__func__,
llu(op->tag),
op);
orangefs_clean_up_interrupted_operation(op);
ret = -EINTR;
break;
}
/*
* if this was our first attempt and client-core
* has not purged our operation, we are happy to
* simply wait
*/
if (op->attempts == 0 && !op_state_purged(op)) {
spin_unlock(&op->lock);
schedule();
} else {
spin_unlock(&op->lock);
/*
* subsequent attempts, we retry exactly once
* with timeouts
*/
if (!schedule_timeout(op_timeout_secs * HZ)) {
gossip_debug(GOSSIP_WAIT_DEBUG,
"*** %s:"
" operation timed out (tag"
" %llu, %p, att %d)\n",
__func__,
llu(op->tag),
op,
op->attempts);
ret = -ETIMEDOUT;
spin_lock(&op->lock);
orangefs_clean_up_interrupted_operation(op);
break;
}
}
spin_lock(&op->lock);
op->attempts++;
/*
* if the operation was purged in the meantime, it
* is better to requeue it afresh but ensure that
* we have not been purged repeatedly. This could
* happen if client-core crashes when an op
* is being serviced, so we requeue the op, client
* core crashes again so we requeue the op, client
* core starts, and so on...
*/
if (op_state_purged(op)) {
ret = (op->attempts < ORANGEFS_PURGE_RETRY_COUNT) ?
-EAGAIN :
-EIO;
gossip_debug(GOSSIP_WAIT_DEBUG,
"*** %s:"
" operation purged (tag "
"%llu, %p, att %d)\n",
__func__,
llu(op->tag),
op,
op->attempts);
orangefs_clean_up_interrupted_operation(op);
break;
}
spin_unlock(&op->lock);
}
spin_lock(&op->lock);
finish_wait(&op->waitq, &wait_entry);
spin_unlock(&op->lock);
return ret;
}
/*
* similar to wait_for_matching_downcall(), but used in the special case
* of I/O cancellations.
*
* Note we need a special wait function because if this is called we already
* know that a signal is pending in current and need to service the
* cancellation upcall anyway. the only way to exit this is to either
* timeout or have the cancellation be serviced properly.
*/
static int wait_for_cancellation_downcall(struct orangefs_kernel_op_s *op)
{
int ret = -EINVAL;
DEFINE_WAIT(wait_entry);
while (1) {
spin_lock(&op->lock);
prepare_to_wait(&op->waitq, &wait_entry, TASK_INTERRUPTIBLE);
if (op_state_serviced(op)) {
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s:op-state is SERVICED.\n",
__func__);
spin_unlock(&op->lock);
ret = 0;
break;
}
if (signal_pending(current)) {
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s:operation interrupted by a signal (tag"
" %llu, op %p)\n",
__func__,
llu(op->tag),
op);
orangefs_clean_up_interrupted_operation(op);
ret = -EINTR;
break;
}
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s:About to call schedule_timeout.\n",
__func__);
spin_unlock(&op->lock);
ret = schedule_timeout(op_timeout_secs * HZ);
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s:Value returned from schedule_timeout(%d).\n",
__func__,
ret);
if (!ret) {
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s:*** operation timed out: %p\n",
__func__,
op);
spin_lock(&op->lock);
orangefs_clean_up_interrupted_operation(op);
ret = -ETIMEDOUT;
break;
}
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s:Breaking out of loop, regardless of value returned by schedule_timeout.\n",
__func__);
ret = -ETIMEDOUT;
break;
}
spin_lock(&op->lock);
finish_wait(&op->waitq, &wait_entry);
spin_unlock(&op->lock);
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s:returning ret(%d)\n",
__func__,
ret);
return ret;
}
