diff options
Diffstat (limited to 'fs/orangefs/waitqueue.c')
| -rw-r--r-- | fs/orangefs/waitqueue.c | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/fs/orangefs/waitqueue.c b/fs/orangefs/waitqueue.c new file mode 100644 index 000000000000..31635bc303fe --- /dev/null +++ b/fs/orangefs/waitqueue.c @@ -0,0 +1,357 @@ +/* + * (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(&request_mutex); + else + ret = mutex_lock_killable(&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(&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(&htable_ops_in_progress_lock); + list_del_init(&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 { + 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; +} |
