/*
* (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_matching_downcall(struct orangefs_kernel_op_s *, long, bool);
static void orangefs_clean_up_interrupted_operation(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));
set_op_state_purged(op);
gossip_debug(GOSSIP_DEV_DEBUG,
"%s: op:%s: op_state:%d: process:%s:\n",
__func__,
get_opname_string(op),
op->op_state,
current->comm);
}
spin_unlock(&orangefs_request_list_lock);
}
/*
* 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)
{
long timeout = MAX_SCHEDULE_TIMEOUT;
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,
"%s: %s op:%p: process:%s: pid:%d:\n",
__func__,
op_name,
op,
current->comm,
current->pid);
/*
* If ORANGEFS_OP_NO_MUTEX was set in flags, we need to avoid
* acquiring the request_mutex because we're servicing a
* high priority remount operation and the request_mutex is
* already taken.
*/
if (!(flags & ORANGEFS_OP_NO_MUTEX)) {
if (flags & ORANGEFS_OP_INTERRUPTIBLE)
ret = mutex_lock_interruptible(&orangefs_request_mutex);
else
ret = mutex_lock_killable(&orangefs_request_mutex);
/*
* check to see if we were interrupted while waiting for
* mutex
*/
if (ret < 0) {
op->downcall.status = ret;
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s: service_operation interrupted.\n",
__func__);
return ret;
}
}
/* queue up the operation */
spin_lock(&orangefs_request_list_lock);
spin_lock(&op->lock);
set_op_state_waiting(op);
gossip_debug(GOSSIP_DEV_DEBUG,
"%s: op:%s: op_state:%d: process:%s:\n",
__func__,
get_opname_string(op),
op->op_state,
current->comm);
/* add high priority remount op to the front of the line. */
if (flags & ORANGEFS_OP_PRIORITY)
list_add(&op->list, &orangefs_request_list);
else
list_add_tail(&op->list, &orangefs_request_list);
spin_unlock(&op->lock);
wake_up_interruptible(&orangefs_request_list_waitq);
if (!__is_daemon_in_service()) {
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s:client core is NOT in service.\n",
__func__);
timeout = op_timeout_secs * HZ;
}
spin_unlock(&orangefs_request_list_lock);
if (!(flags & ORANGEFS_OP_NO_MUTEX))
mutex_unlock(&orangefs_request_mutex);
ret = wait_for_matching_downcall(op, timeout,
flags & ORANGEFS_OP_INTERRUPTIBLE);
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s: wait_for_matching_downcall returned %d for %p\n",
__func__,
ret,
op);
/* got matching downcall; make sure status is in errno format */
if (!ret) {
spin_unlock(&op->lock);
op->downcall.status =
orangefs_normalize_to_errno(op->downcall.status);
ret = op->downcall.status;
goto out;
}
/* failed to get matching downcall */
if (ret == -ETIMEDOUT) {
gossip_err("%s: %s -- wait timed out; aborting attempt.\n",
__func__,
op_name);
}
/*
* remove a waiting op from the request list or
* remove an in-progress op from the in-progress list.
*/
orangefs_clean_up_interrupted_operation(op);
op->downcall.status = ret;
/* retry if operation has not been serviced and if requested */
if (ret == -EAGAIN) {
op->attempts++;
timeout = op_timeout_secs * HZ;
gossip_debug(GOSSIP_WAIT_DEBUG,
"orangefs: tag %llu (%s)"
" -- operation to be retried (%d attempt)\n",
llu(op->tag),
op_name,
op->attempts);
/*
* io ops (ops that use the shared memory buffer) have
* to be returned to their caller for a retry. Other ops
* can just be recycled here.
*/
if (!op->uses_shared_memory)
goto retry_servicing;
}
out:
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s: %s returning: %d for %p.\n",
__func__,
op_name,
ret,
op);
return ret;
}
/* This can get called on an I/O op if it had a bad service_operation. */
bool orangefs_cancel_op_in_progress(struct orangefs_kernel_op_s *op)
{
u64 tag = op->tag;
if (!op_state_in_progress(op))
return false;
op->slot_to_free = op->upcall.req.io.buf_index;
memset(&op->upcall, 0, sizeof(op->upcall));
memset(&op->downcall, 0, sizeof(op->downcall));
op->upcall.type = ORANGEFS_VFS_OP_CANCEL;
op->upcall.req.cancel.op_tag = tag;
op->downcall.type = ORANGEFS_VFS_OP_INVALID;
op->downcall.status = -1;
orangefs_new_tag(op);
spin_lock(&orangefs_request_list_lock);
/* orangefs_request_list_lock is enough of a barrier here */
if (!__is_daemon_in_service()) {
spin_unlock(&orangefs_request_list_lock);
return false;
}
spin_lock(&op->lock);
set_op_state_waiting(op);
gossip_debug(GOSSIP_DEV_DEBUG,
"%s: op:%s: op_state:%d: process:%s:\n",
__func__,
get_opname_string(op),
op->op_state,
current->comm);
list_add(&op->list, &orangefs_request_list);
spin_unlock(&op->lock);
spin_unlock(&orangefs_request_list_lock);
gossip_debug(GOSSIP_WAIT_DEBUG,
"Attempting ORANGEFS operation cancellation of tag %llu\n",
llu(tag));
return true;
}
/*
* Change an op to the "given up" state and remove it from its list.
*/
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.
*
* Called with op->lock held.
*/
/*
* List manipulation code elsewhere will ignore ops that
* have been given up upon.
*/
op->op_state |= OP_VFS_STATE_GIVEN_UP;
if (list_empty(&op->list)) {
/* caught copying to/from daemon */
BUG_ON(op_state_serviced(op));
spin_unlock(&op->lock);
wait_for_completion(&op->waitq);
} else 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_init(&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(&orangefs_htable_ops_in_progress_lock);
list_del_init(&op->list);
spin_unlock(&orangefs_htable_ops_in_progress_lock);
gossip_debug(GOSSIP_WAIT_DEBUG,
"Interrupted: Removed op %p"
" from htable_ops_in_progress\n",
op);
} else {
spin_unlock(&op->lock);
gossip_err("interrupted operation is in a weird state 0x%x\n",
op->op_state);
}
reinit_completion(&op->waitq);
}
/*
* 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
*
* When this call returns to the caller, the specified op will no
* longer be in either the in_progress hash table or on the request list.
*
* 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.
*
* Returns with op->lock taken.
*/
static int wait_for_matching_downcall(struct orangefs_kernel_op_s *op,
long timeout,
bool interruptible)
{
long n;
/*
* There's a "schedule_timeout" inside of these wait
* primitives, during which the op is out of the hands of the
* user process that needs something done and is being
* manipulated by the client-core process.
*/
if (interruptible)
n = wait_for_completion_interruptible_timeout(&op->waitq,
timeout);
else
n = wait_for_completion_killable_timeout(&op->waitq, timeout);
spin_lock(&op->lock);
if (op_state_serviced(op))
return 0;
if (unlikely(n < 0)) {
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s: operation interrupted, tag %llu, %p\n",
__func__,
llu(op->tag),
op);
return -EINTR;
}
if (op_state_purged(op)) {
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s: operation purged, tag %llu, %p, %d\n",
__func__,
llu(op->tag),
op,
op->attempts);
return (op->attempts < ORANGEFS_PURGE_RETRY_COUNT) ?
-EAGAIN :
-EIO;
}
/* must have timed out, then... */
gossip_debug(GOSSIP_WAIT_DEBUG,
"%s: operation timed out, tag %llu, %p, %d)\n",
__func__,
llu(op->tag),
op,
op->attempts);
return -ETIMEDOUT;
}