diff options
Diffstat (limited to 'net/9p/mux.c')
| -rw-r--r-- | net/9p/mux.c | 1060 |
1 files changed, 0 insertions, 1060 deletions
diff --git a/net/9p/mux.c b/net/9p/mux.c deleted file mode 100644 index c9f0805048e4..000000000000 --- a/net/9p/mux.c +++ /dev/null @@ -1,1060 +0,0 @@ -/* - * net/9p/mux.c - * - * Protocol Multiplexer - * - * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com> - * Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 - * as published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to: - * Free Software Foundation - * 51 Franklin Street, Fifth Floor - * Boston, MA 02111-1301 USA - * - */ - -#include <linux/module.h> -#include <linux/errno.h> -#include <linux/fs.h> -#include <linux/poll.h> -#include <linux/kthread.h> -#include <linux/idr.h> -#include <linux/mutex.h> -#include <net/9p/9p.h> -#include <linux/parser.h> -#include <net/9p/transport.h> -#include <net/9p/conn.h> - -#define ERREQFLUSH 1 -#define SCHED_TIMEOUT 10 -#define MAXPOLLWADDR 2 - -enum { - Rworksched = 1, /* read work scheduled or running */ - Rpending = 2, /* can read */ - Wworksched = 4, /* write work scheduled or running */ - Wpending = 8, /* can write */ -}; - -enum { - None, - Flushing, - Flushed, -}; - -struct p9_mux_poll_task; - -struct p9_req { - spinlock_t lock; /* protect request structure */ - int tag; - struct p9_fcall *tcall; - struct p9_fcall *rcall; - int err; - p9_conn_req_callback cb; - void *cba; - int flush; - struct list_head req_list; -}; - -struct p9_conn { - spinlock_t lock; /* protect lock structure */ - struct list_head mux_list; - struct p9_mux_poll_task *poll_task; - int msize; - unsigned char *extended; - struct p9_trans *trans; - struct p9_idpool *tagpool; - int err; - wait_queue_head_t equeue; - struct list_head req_list; - struct list_head unsent_req_list; - struct p9_fcall *rcall; - int rpos; - char *rbuf; - int wpos; - int wsize; - char *wbuf; - wait_queue_t poll_wait[MAXPOLLWADDR]; - wait_queue_head_t *poll_waddr[MAXPOLLWADDR]; - poll_table pt; - struct work_struct rq; - struct work_struct wq; - unsigned long wsched; -}; - -struct p9_mux_poll_task { - struct task_struct *task; - struct list_head mux_list; - int muxnum; -}; - -struct p9_mux_rpc { - struct p9_conn *m; - int err; - struct p9_fcall *tcall; - struct p9_fcall *rcall; - wait_queue_head_t wqueue; -}; - -static int p9_poll_proc(void *); -static void p9_read_work(struct work_struct *work); -static void p9_write_work(struct work_struct *work); -static void p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, - poll_table * p); -static u16 p9_mux_get_tag(struct p9_conn *); -static void p9_mux_put_tag(struct p9_conn *, u16); - -static DEFINE_MUTEX(p9_mux_task_lock); -static struct workqueue_struct *p9_mux_wq; - -static int p9_mux_num; -static int p9_mux_poll_task_num; -static struct p9_mux_poll_task p9_mux_poll_tasks[100]; - -int p9_mux_global_init(void) -{ - int i; - - for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++) - p9_mux_poll_tasks[i].task = NULL; - - p9_mux_wq = create_workqueue("v9fs"); - if (!p9_mux_wq) { - printk(KERN_WARNING "v9fs: mux: creating workqueue failed\n"); - return -ENOMEM; - } - - return 0; -} - -void p9_mux_global_exit(void) -{ - destroy_workqueue(p9_mux_wq); -} - -/** - * p9_mux_calc_poll_procs - calculates the number of polling procs - * based on the number of mounted v9fs filesystems. - * - * The current implementation returns sqrt of the number of mounts. - */ -static int p9_mux_calc_poll_procs(int muxnum) -{ - int n; - - if (p9_mux_poll_task_num) - n = muxnum / p9_mux_poll_task_num + - (muxnum % p9_mux_poll_task_num ? 1 : 0); - else - n = 1; - - if (n > ARRAY_SIZE(p9_mux_poll_tasks)) - n = ARRAY_SIZE(p9_mux_poll_tasks); - - return n; -} - -static int p9_mux_poll_start(struct p9_conn *m) -{ - int i, n; - struct p9_mux_poll_task *vpt, *vptlast; - struct task_struct *pproc; - - P9_DPRINTK(P9_DEBUG_MUX, "mux %p muxnum %d procnum %d\n", m, p9_mux_num, - p9_mux_poll_task_num); - mutex_lock(&p9_mux_task_lock); - - n = p9_mux_calc_poll_procs(p9_mux_num + 1); - if (n > p9_mux_poll_task_num) { - for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++) { - if (p9_mux_poll_tasks[i].task == NULL) { - vpt = &p9_mux_poll_tasks[i]; - P9_DPRINTK(P9_DEBUG_MUX, "create proc %p\n", - vpt); - pproc = kthread_create(p9_poll_proc, vpt, - "v9fs-poll"); - - if (!IS_ERR(pproc)) { - vpt->task = pproc; - INIT_LIST_HEAD(&vpt->mux_list); - vpt->muxnum = 0; - p9_mux_poll_task_num++; - wake_up_process(vpt->task); - } - break; - } - } - - if (i >= ARRAY_SIZE(p9_mux_poll_tasks)) - P9_DPRINTK(P9_DEBUG_ERROR, - "warning: no free poll slots\n"); - } - - n = (p9_mux_num + 1) / p9_mux_poll_task_num + - ((p9_mux_num + 1) % p9_mux_poll_task_num ? 1 : 0); - - vptlast = NULL; - for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++) { - vpt = &p9_mux_poll_tasks[i]; - if (vpt->task != NULL) { - vptlast = vpt; - if (vpt->muxnum < n) { - P9_DPRINTK(P9_DEBUG_MUX, "put in proc %d\n", i); - list_add(&m->mux_list, &vpt->mux_list); - vpt->muxnum++; - m->poll_task = vpt; - memset(&m->poll_waddr, 0, - sizeof(m->poll_waddr)); - init_poll_funcptr(&m->pt, p9_pollwait); - break; - } - } - } - - if (i >= ARRAY_SIZE(p9_mux_poll_tasks)) { - if (vptlast == NULL) { - mutex_unlock(&p9_mux_task_lock); - return -ENOMEM; - } - - P9_DPRINTK(P9_DEBUG_MUX, "put in proc %d\n", i); - list_add(&m->mux_list, &vptlast->mux_list); - vptlast->muxnum++; - m->poll_task = vptlast; - memset(&m->poll_waddr, 0, sizeof(m->poll_waddr)); - init_poll_funcptr(&m->pt, p9_pollwait); - } - - p9_mux_num++; - mutex_unlock(&p9_mux_task_lock); - - return 0; -} - -static void p9_mux_poll_stop(struct p9_conn *m) -{ - int i; - struct p9_mux_poll_task *vpt; - - mutex_lock(&p9_mux_task_lock); - vpt = m->poll_task; - list_del(&m->mux_list); - for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) { - if (m->poll_waddr[i] != NULL) { - remove_wait_queue(m->poll_waddr[i], &m->poll_wait[i]); - m->poll_waddr[i] = NULL; - } - } - vpt->muxnum--; - if (!vpt->muxnum) { - P9_DPRINTK(P9_DEBUG_MUX, "destroy proc %p\n", vpt); - kthread_stop(vpt->task); - vpt->task = NULL; - p9_mux_poll_task_num--; - } - p9_mux_num--; - mutex_unlock(&p9_mux_task_lock); -} - -/** - * p9_conn_create - allocate and initialize the per-session mux data - * Creates the polling task if this is the first session. - * - * @trans - transport structure - * @msize - maximum message size - * @extended - pointer to the extended flag - */ -struct p9_conn *p9_conn_create(struct p9_trans *trans, int msize, - unsigned char *extended) -{ - int i, n; - struct p9_conn *m, *mtmp; - - P9_DPRINTK(P9_DEBUG_MUX, "transport %p msize %d\n", trans, msize); - m = kmalloc(sizeof(struct p9_conn), GFP_KERNEL); - if (!m) - return ERR_PTR(-ENOMEM); - - spin_lock_init(&m->lock); - INIT_LIST_HEAD(&m->mux_list); - m->msize = msize; - m->extended = extended; - m->trans = trans; - m->tagpool = p9_idpool_create(); - if (IS_ERR(m->tagpool)) { - mtmp = ERR_PTR(-ENOMEM); - kfree(m); - return mtmp; - } - - m->err = 0; - init_waitqueue_head(&m->equeue); - INIT_LIST_HEAD(&m->req_list); - INIT_LIST_HEAD(&m->unsent_req_list); - m->rcall = NULL; - m->rpos = 0; - m->rbuf = NULL; - m->wpos = m->wsize = 0; - m->wbuf = NULL; - INIT_WORK(&m->rq, p9_read_work); - INIT_WORK(&m->wq, p9_write_work); - m->wsched = 0; - memset(&m->poll_waddr, 0, sizeof(m->poll_waddr)); - m->poll_task = NULL; - n = p9_mux_poll_start(m); - if (n) { - kfree(m); - return ERR_PTR(n); - } - - n = trans->poll(trans, &m->pt); - if (n & POLLIN) { - P9_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m); - set_bit(Rpending, &m->wsched); - } - - if (n & POLLOUT) { - P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m); - set_bit(Wpending, &m->wsched); - } - - for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) { - if (IS_ERR(m->poll_waddr[i])) { - p9_mux_poll_stop(m); - mtmp = (void *)m->poll_waddr; /* the error code */ - kfree(m); - m = mtmp; - break; - } - } - - return m; -} -EXPORT_SYMBOL(p9_conn_create); - -/** - * p9_mux_destroy - cancels all pending requests and frees mux resources - */ -void p9_conn_destroy(struct p9_conn *m) -{ - P9_DPRINTK(P9_DEBUG_MUX, "mux %p prev %p next %p\n", m, - m->mux_list.prev, m->mux_list.next); - p9_conn_cancel(m, -ECONNRESET); - - if (!list_empty(&m->req_list)) { - /* wait until all processes waiting on this session exit */ - P9_DPRINTK(P9_DEBUG_MUX, - "mux %p waiting for empty request queue\n", m); - wait_event_timeout(m->equeue, (list_empty(&m->req_list)), 5000); - P9_DPRINTK(P9_DEBUG_MUX, "mux %p request queue empty: %d\n", m, - list_empty(&m->req_list)); - } - - p9_mux_poll_stop(m); - m->trans = NULL; - p9_idpool_destroy(m->tagpool); - kfree(m); -} -EXPORT_SYMBOL(p9_conn_destroy); - -/** - * p9_pollwait - called by files poll operation to add v9fs-poll task - * to files wait queue - */ -static void -p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, - poll_table * p) -{ - int i; - struct p9_conn *m; - - m = container_of(p, struct p9_conn, pt); - for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) - if (m->poll_waddr[i] == NULL) - break; - - if (i >= ARRAY_SIZE(m->poll_waddr)) { - P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n"); - return; - } - - m->poll_waddr[i] = wait_address; - - if (!wait_address) { - P9_DPRINTK(P9_DEBUG_ERROR, "no wait_address\n"); - m->poll_waddr[i] = ERR_PTR(-EIO); - return; - } - - init_waitqueue_entry(&m->poll_wait[i], m->poll_task->task); - add_wait_queue(wait_address, &m->poll_wait[i]); -} - -/** - * p9_poll_mux - polls a mux and schedules read or write works if necessary - */ -static void p9_poll_mux(struct p9_conn *m) -{ - int n; - - if (m->err < 0) - return; - - n = m->trans->poll(m->trans, NULL); - if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) { - P9_DPRINTK(P9_DEBUG_MUX, "error mux %p err %d\n", m, n); - if (n >= 0) - n = -ECONNRESET; - p9_conn_cancel(m, n); - } - - if (n & POLLIN) { - set_bit(Rpending, &m->wsched); - P9_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m); - if (!test_and_set_bit(Rworksched, &m->wsched)) { - P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m); - queue_work(p9_mux_wq, &m->rq); - } - } - - if (n & POLLOUT) { - set_bit(Wpending, &m->wsched); - P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m); - if ((m->wsize || !list_empty(&m->unsent_req_list)) - && !test_and_set_bit(Wworksched, &m->wsched)) { - P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m); - queue_work(p9_mux_wq, &m->wq); - } - } -} - -/** - * p9_poll_proc - polls all v9fs transports for new events and queues - * the appropriate work to the work queue - */ -static int p9_poll_proc(void *a) -{ - struct p9_conn *m, *mtmp; - struct p9_mux_poll_task *vpt; - - vpt = a; - P9_DPRINTK(P9_DEBUG_MUX, "start %p %p\n", current, vpt); - while (!kthread_should_stop()) { - set_current_state(TASK_INTERRUPTIBLE); - - list_for_each_entry_safe(m, mtmp, &vpt->mux_list, mux_list) { - p9_poll_mux(m); - } - - P9_DPRINTK(P9_DEBUG_MUX, "sleeping...\n"); - schedule_timeout(SCHED_TIMEOUT * HZ); - } - - __set_current_state(TASK_RUNNING); - P9_DPRINTK(P9_DEBUG_MUX, "finish\n"); - return 0; -} - -/** - * p9_write_work - called when a transport can send some data - */ -static void p9_write_work(struct work_struct *work) -{ - int n, err; - struct p9_conn *m; - struct p9_req *req; - - m = container_of(work, struct p9_conn, wq); - - if (m->err < 0) { - clear_bit(Wworksched, &m->wsched); - return; - } - - if (!m->wsize) { - if (list_empty(&m->unsent_req_list)) { - clear_bit(Wworksched, &m->wsched); - return; - } - - spin_lock(&m->lock); -again: - req = list_entry(m->unsent_req_list.next, struct p9_req, - req_list); - list_move_tail(&req->req_list, &m->req_list); - if (req->err == ERREQFLUSH) - goto again; - - m->wbuf = req->tcall->sdata; - m->wsize = req->tcall->size; - m->wpos = 0; - spin_unlock(&m->lock); - } - - P9_DPRINTK(P9_DEBUG_MUX, "mux %p pos %d size %d\n", m, m->wpos, - m->wsize); - clear_bit(Wpending, &m->wsched); - err = m->trans->write(m->trans, m->wbuf + m->wpos, m->wsize - m->wpos); - P9_DPRINTK(P9_DEBUG_MUX, "mux %p sent %d bytes\n", m, err); - if (err == -EAGAIN) { - clear_bit(Wworksched, &m->wsched); - return; - } - - if (err < 0) - goto error; - else if (err == 0) { - err = -EREMOTEIO; - goto error; - } - - m->wpos += err; - if (m->wpos == m->wsize) - m->wpos = m->wsize = 0; - - if (m->wsize == 0 && !list_empty(&m->unsent_req_list)) { - if (test_and_clear_bit(Wpending, &m->wsched)) - n = POLLOUT; - else - n = m->trans->poll(m->trans, NULL); - - if (n & POLLOUT) { - P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m); - queue_work(p9_mux_wq, &m->wq); - } else - clear_bit(Wworksched, &m->wsched); - } else - clear_bit(Wworksched, &m->wsched); - - return; - -error: - p9_conn_cancel(m, err); - clear_bit(Wworksched, &m->wsched); -} - -static void process_request(struct p9_conn *m, struct p9_req *req) -{ - int ecode; - struct p9_str *ename; - - if (!req->err && req->rcall->id == P9_RERROR) { - ecode = req->rcall->params.rerror.errno; - ename = &req->rcall->params.rerror.error; - - P9_DPRINTK(P9_DEBUG_MUX, "Rerror %.*s\n", ename->len, - ename->str); - - if (*m->extended) - req->err = -ecode; - - if (!req->err) { - req->err = p9_errstr2errno(ename->str, ename->len); - - if (!req->err) { /* string match failed */ - PRINT_FCALL_ERROR("unknown error", req->rcall); - } - - if (!req->err) - req->err = -ESERVERFAULT; - } - } else if (req->tcall && req->rcall->id != req->tcall->id + 1) { - P9_DPRINTK(P9_DEBUG_ERROR, - "fcall mismatch: expected %d, got %d\n", - req->tcall->id + 1, req->rcall->id); - if (!req->err) - req->err = -EIO; - } -} - -/** - * p9_read_work - called when there is some data to be read from a transport - */ -static void p9_read_work(struct work_struct *work) -{ - int n, err; - struct p9_conn *m; - struct p9_req *req, *rptr, *rreq; - struct p9_fcall *rcall; - char *rbuf; - - m = container_of(work, struct p9_conn, rq); - - if (m->err < 0) - return; - - rcall = NULL; - P9_DPRINTK(P9_DEBUG_MUX, "start mux %p pos %d\n", m, m->rpos); - - if (!m->rcall) { - m->rcall = - kmalloc(sizeof(struct p9_fcall) + m->msize, GFP_KERNEL); - if (!m->rcall) { - err = -ENOMEM; - goto error; - } - - m->rbuf = (char *)m->rcall + sizeof(struct p9_fcall); - m->rpos = 0; - } - - clear_bit(Rpending, &m->wsched); - err = m->trans->read(m->trans, m->rbuf + m->rpos, m->msize - m->rpos); - P9_DPRINTK(P9_DEBUG_MUX, "mux %p got %d bytes\n", m, err); - if (err == -EAGAIN) { - clear_bit(Rworksched, &m->wsched); - return; - } - - if (err <= 0) - goto error; - - m->rpos += err; - while (m->rpos > 4) { - n = le32_to_cpu(*(__le32 *) m->rbuf); - if (n >= m->msize) { - P9_DPRINTK(P9_DEBUG_ERROR, - "requested packet size too big: %d\n", n); - err = -EIO; - goto error; - } - - if (m->rpos < n) - break; - - err = - p9_deserialize_fcall(m->rbuf, n, m->rcall, *m->extended); - if (err < 0) { - goto error; - } - -#ifdef CONFIG_NET_9P_DEBUG - if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) { - char buf[150]; - - p9_printfcall(buf, sizeof(buf), m->rcall, - *m->extended); - printk(KERN_NOTICE ">>> %p %s\n", m, buf); - } -#endif - - rcall = m->rcall; - rbuf = m->rbuf; - if (m->rpos > n) { - m->rcall = kmalloc(sizeof(struct p9_fcall) + m->msize, - GFP_KERNEL); - if (!m->rcall) { - err = -ENOMEM; - goto error; - } - - m->rbuf = (char *)m->rcall + sizeof(struct p9_fcall); - memmove(m->rbuf, rbuf + n, m->rpos - n); - m->rpos -= n; - } else { - m->rcall = NULL; - m->rbuf = NULL; - m->rpos = 0; - } - - P9_DPRINTK(P9_DEBUG_MUX, "mux %p fcall id %d tag %d\n", m, - rcall->id, rcall->tag); - - req = NULL; - spin_lock(&m->lock); - list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) { - if (rreq->tag == rcall->tag) { - req = rreq; - if (req->flush != Flushing) - list_del(&req->req_list); - break; - } - } - spin_unlock(&m->lock); - - if (req) { - req->rcall = rcall; - process_request(m, req); - - if (req->flush != Flushing) { - if (req->cb) - (*req->cb) (req, req->cba); - else - kfree(req->rcall); - - wake_up(&m->equeue); - } - } else { - if (err >= 0 && rcall->id != P9_RFLUSH) - P9_DPRINTK(P9_DEBUG_ERROR, - "unexpected response mux %p id %d tag %d\n", - m, rcall->id, rcall->tag); - kfree(rcall); - } - } - - if (!list_empty(&m->req_list)) { - if (test_and_clear_bit(Rpending, &m->wsched)) - n = POLLIN; - else - n = m->trans->poll(m->trans, NULL); - - if (n & POLLIN) { - P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m); - queue_work(p9_mux_wq, &m->rq); - } else - clear_bit(Rworksched, &m->wsched); - } else - clear_bit(Rworksched, &m->wsched); - - return; - -error: - p9_conn_cancel(m, err); - clear_bit(Rworksched, &m->wsched); -} - -/** - * p9_send_request - send 9P request - * The function can sleep until the request is scheduled for sending. - * The function can be interrupted. Return from the function is not - * a guarantee that the request is sent successfully. Can return errors - * that can be retrieved by PTR_ERR macros. - * - * @m: mux data - * @tc: request to be sent - * @cb: callback function to call when response is received - * @cba: parameter to pass to the callback function - */ -static struct p9_req *p9_send_request(struct p9_conn *m, - struct p9_fcall *tc, - p9_conn_req_callback cb, void *cba) -{ - int n; - struct p9_req *req; - - P9_DPRINTK(P9_DEBUG_MUX, "mux %p task %p tcall %p id %d\n", m, current, - tc, tc->id); - if (m->err < 0) - return ERR_PTR(m->err); - - req = kmalloc(sizeof(struct p9_req), GFP_KERNEL); - if (!req) - return ERR_PTR(-ENOMEM); - - if (tc->id == P9_TVERSION) - n = P9_NOTAG; - else - n = p9_mux_get_tag(m); - - if (n < 0) - return ERR_PTR(-ENOMEM); - - p9_set_tag(tc, n); - -#ifdef CONFIG_NET_9P_DEBUG - if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) { - char buf[150]; - - p9_printfcall(buf, sizeof(buf), tc, *m->extended); - printk(KERN_NOTICE "<<< %p %s\n", m, buf); - } -#endif - - spin_lock_init(&req->lock); - req->tag = n; - req->tcall = tc; - req->rcall = NULL; - req->err = 0; - req->cb = cb; - req->cba = cba; - req->flush = None; - - spin_lock(&m->lock); - list_add_tail(&req->req_list, &m->unsent_req_list); - spin_unlock(&m->lock); - - if (test_and_clear_bit(Wpending, &m->wsched)) - n = POLLOUT; - else - n = m->trans->poll(m->trans, NULL); - - if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched)) - queue_work(p9_mux_wq, &m->wq); - - return req; -} - -static void p9_mux_free_request(struct p9_conn *m, struct p9_req *req) -{ - p9_mux_put_tag(m, req->tag); - kfree(req); -} - -static void p9_mux_flush_cb(struct p9_req *freq, void *a) -{ - p9_conn_req_callback cb; - int tag; - struct p9_conn *m; - struct p9_req *req, *rreq, *rptr; - - m = a; - P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p rc %p err %d oldtag %d\n", m, - freq->tcall, freq->rcall, freq->err, - freq->tcall->params.tflush.oldtag); - - spin_lock(&m->lock); - cb = NULL; - tag = freq->tcall->params.tflush.oldtag; - req = NULL; - list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) { - if (rreq->tag == tag) { - req = rreq; - list_del(&req->req_list); - break; - } - } - spin_unlock(&m->lock); - - if (req) { - spin_lock(&req->lock); - req->flush = Flushed; - spin_unlock(&req->lock); - - if (req->cb) - (*req->cb) (req, req->cba); - else - kfree(req->rcall); - - wake_up(&m->equeue); - } - - kfree(freq->tcall); - kfree(freq->rcall); - p9_mux_free_request(m, freq); -} - -static int -p9_mux_flush_request(struct p9_conn *m, struct p9_req *req) -{ - struct p9_fcall *fc; - struct p9_req *rreq, *rptr; - - P9_DPRINTK(P9_DEBUG_MUX, "mux %p req %p tag %d\n", m, req, req->tag); - - /* if a response was received for a request, do nothing */ - spin_lock(&req->lock); - if (req->rcall || req->err) { - spin_unlock(&req->lock); - P9_DPRINTK(P9_DEBUG_MUX, - "mux %p req %p response already received\n", m, req); - return 0; - } - - req->flush = Flushing; - spin_unlock(&req->lock); - - spin_lock(&m->lock); - /* if the request is not sent yet, just remove it from the list */ - list_for_each_entry_safe(rreq, rptr, &m->unsent_req_list, req_list) { - if (rreq->tag == req->tag) { - P9_DPRINTK(P9_DEBUG_MUX, - "mux %p req %p request is not sent yet\n", m, req); - list_del(&rreq->req_list); - req->flush = Flushed; - spin_unlock(&m->lock); - if (req->cb) - (*req->cb) (req, req->cba); - return 0; - } - } - spin_unlock(&m->lock); - - clear_thread_flag(TIF_SIGPENDING); - fc = p9_create_tflush(req->tag); - p9_send_request(m, fc, p9_mux_flush_cb, m); - return 1; -} - -static void -p9_conn_rpc_cb(struct p9_req *req, void *a) -{ - struct p9_mux_rpc *r; - - P9_DPRINTK(P9_DEBUG_MUX, "req %p r %p\n", req, a); - r = a; - r->rcall = req->rcall; - r->err = req->err; - - if (req->flush != None && !req->err) - r->err = -ERESTARTSYS; - - wake_up(&r->wqueue); -} - -/** - * p9_mux_rpc - sends 9P request and waits until a response is available. - * The function can be interrupted. - * @m: mux data - * @tc: request to be sent - * @rc: pointer where a pointer to the response is stored - */ -int -p9_conn_rpc(struct p9_conn *m, struct p9_fcall *tc, - struct p9_fcall **rc) -{ - int err, sigpending; - unsigned long flags; - struct p9_req *req; - struct p9_mux_rpc r; - - r.err = 0; - r.tcall = tc; - r.rcall = NULL; - r.m = m; - init_waitqueue_head(&r.wqueue); - - if (rc) - *rc = NULL; - - sigpending = 0; - if (signal_pending(current)) { - sigpending = 1; - clear_thread_flag(TIF_SIGPENDING); - } - - req = p9_send_request(m, tc, p9_conn_rpc_cb, &r); - if (IS_ERR(req)) { - err = PTR_ERR(req); - P9_DPRINTK(P9_DEBUG_MUX, "error %d\n", err); - return err; - } - - err = wait_event_interruptible(r.wqueue, r.rcall != NULL || r.err < 0); - if (r.err < 0) - err = r.err; - - if (err == -ERESTARTSYS && m->trans->status == Connected - && m->err == 0) { - if (p9_mux_flush_request(m, req)) { - /* wait until we get response of the flush message */ - do { - clear_thread_flag(TIF_SIGPENDING); - err = wait_event_interruptible(r.wqueue, - r.rcall || r.err); - } while (!r.rcall && !r.err && err == -ERESTARTSYS && - m->trans->status == Connected && !m->err); - - err = -ERESTARTSYS; - } - sigpending = 1; - } - - if (sigpending) { - spin_lock_irqsave(¤t->sighand->siglock, flags); - recalc_sigpending(); - spin_unlock_irqrestore(¤t->sighand->siglock, flags); - } - - if (rc) - *rc = r.rcall; - else - kfree(r.rcall); - - p9_mux_free_request(m, req); - if (err > 0) - err = -EIO; - - return err; -} -EXPORT_SYMBOL(p9_conn_rpc); - -#ifdef P9_NONBLOCK -/** - * p9_conn_rpcnb - sends 9P request without waiting for response. - * @m: mux data - * @tc: request to be sent - * @cb: callback function to be called when response arrives - * @cba: value to pass to the callback function - */ -int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc, - p9_conn_req_callback cb, void *a) -{ - int err; - struct p9_req *req; - - req = p9_send_request(m, tc, cb, a); - if (IS_ERR(req)) { - err = PTR_ERR(req); - P9_DPRINTK(P9_DEBUG_MUX, "error %d\n", err); - return PTR_ERR(req); - } - - P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p tag %d\n", m, tc, req->tag); - return 0; -} -EXPORT_SYMBOL(p9_conn_rpcnb); -#endif /* P9_NONBLOCK */ - -/** - * p9_conn_cancel - cancel all pending requests with error - * @m: mux data - * @err: error code - */ -void p9_conn_cancel(struct p9_conn *m, int err) -{ - struct p9_req *req, *rtmp; - LIST_HEAD(cancel_list); - - P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err); - m->err = err; - spin_lock(&m->lock); - list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) { - list_move(&req->req_list, &cancel_list); - } - list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) { - list_move(&req->req_list, &cancel_list); - } - spin_unlock(&m->lock); - - list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) { - list_del(&req->req_list); - if (!req->err) - req->err = err; - - if (req->cb) - (*req->cb) (req, req->cba); - else - kfree(req->rcall); - } - - wake_up(&m->equeue); -} -EXPORT_SYMBOL(p9_conn_cancel); - -static u16 p9_mux_get_tag(struct p9_conn *m) -{ - int tag; - - tag = p9_idpool_get(m->tagpool); - if (tag < 0) - return P9_NOTAG; - else - return (u16) tag; -} - -static void p9_mux_put_tag(struct p9_conn *m, u16 tag) -{ - if (tag != P9_NOTAG && p9_idpool_check(tag, m->tagpool)) - p9_idpool_put(tag, m->tagpool); -} |