diff options
| -rw-r--r-- | net/9p/trans_fd.c | 252 |
1 files changed, 86 insertions, 166 deletions
diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c index 6dabbdb66651..f84592345573 100644 --- a/net/9p/trans_fd.c +++ b/net/9p/trans_fd.c @@ -44,7 +44,6 @@ #define P9_PORT 564 #define MAX_SOCK_BUF (64*1024) #define ERREQFLUSH 1 -#define SCHED_TIMEOUT 10 #define MAXPOLLWADDR 2 /** @@ -135,17 +134,16 @@ struct p9_req { struct list_head req_list; }; -struct p9_mux_poll_task { - struct task_struct *task; - struct list_head mux_list; - int muxnum; +struct p9_poll_wait { + struct p9_conn *conn; + wait_queue_t wait; + wait_queue_head_t *wait_addr; }; /** * struct p9_conn - fd mux connection state information * @lock: protects mux_list (?) * @mux_list: list link for mux to manage multiple connections (?) - * @poll_task: task polling on this connection * @msize: maximum size for connection (dup) * @extended: 9p2000.u flag (dup) * @trans: reference to transport instance for this connection @@ -171,7 +169,6 @@ struct p9_mux_poll_task { 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; @@ -185,8 +182,8 @@ struct p9_conn { int wpos; int wsize; char *wbuf; - wait_queue_t poll_wait[MAXPOLLWADDR]; - wait_queue_head_t *poll_waddr[MAXPOLLWADDR]; + struct list_head poll_pending_link; + struct p9_poll_wait poll_wait[MAXPOLLWADDR]; poll_table pt; struct work_struct rq; struct work_struct wq; @@ -220,12 +217,10 @@ static void p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, static int p9_fd_write(struct p9_trans *trans, void *v, int len); static int p9_fd_read(struct p9_trans *trans, void *v, int len); -static DEFINE_MUTEX(p9_mux_task_lock); +static DEFINE_SPINLOCK(p9_poll_lock); +static LIST_HEAD(p9_poll_pending_list); 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]; +static struct task_struct *p9_poll_task; static void p9_conn_destroy(struct p9_conn *); static unsigned int p9_fd_poll(struct p9_trans *trans, @@ -255,130 +250,23 @@ static void p9_mux_put_tag(struct p9_conn *m, u16 tag) p9_idpool_put(tag, m->tagpool); } -/** - * p9_mux_calc_poll_procs - calculates the number of polling procs - * @muxnum: number of mounts - * - * Calculation is 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) +static void p9_mux_poll_stop(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"); - } + unsigned long flags; + int i; - 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; - } - } - } + for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) { + struct p9_poll_wait *pwait = &m->poll_wait[i]; - if (i >= ARRAY_SIZE(p9_mux_poll_tasks)) { - if (vptlast == NULL) { - mutex_unlock(&p9_mux_task_lock); - return -ENOMEM; + if (pwait->wait_addr) { + remove_wait_queue(pwait->wait_addr, &pwait->wait); + pwait->wait_addr = NULL; } - - 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); + spin_lock_irqsave(&p9_poll_lock, flags); + list_del_init(&m->poll_pending_link); + spin_unlock_irqrestore(&p9_poll_lock, flags); } /** @@ -414,11 +302,8 @@ static struct p9_conn *p9_conn_create(struct p9_trans *trans) INIT_LIST_HEAD(&m->unsent_req_list); INIT_WORK(&m->rq, p9_read_work); INIT_WORK(&m->wq, p9_write_work); - n = p9_mux_poll_start(m); - if (n) { - kfree(m); - return ERR_PTR(n); - } + INIT_LIST_HEAD(&m->poll_pending_link); + init_poll_funcptr(&m->pt, p9_pollwait); n = p9_fd_poll(trans, &m->pt); if (n & POLLIN) { @@ -431,11 +316,12 @@ static struct p9_conn *p9_conn_create(struct p9_trans *trans) set_bit(Wpending, &m->wsched); } - for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) { - if (IS_ERR(m->poll_waddr[i])) { + for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) { + if (IS_ERR(m->poll_wait[i].wait_addr)) { p9_mux_poll_stop(m); kfree(m); - return (void *)m->poll_waddr; /* the error code */ + /* return the error code */ + return (void *)m->poll_wait[i].wait_addr; } } @@ -464,6 +350,23 @@ static void p9_conn_destroy(struct p9_conn *m) kfree(m); } +static int p9_pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key) +{ + struct p9_poll_wait *pwait = + container_of(wait, struct p9_poll_wait, wait); + struct p9_conn *m = pwait->conn; + unsigned long flags; + DECLARE_WAITQUEUE(dummy_wait, p9_poll_task); + + spin_lock_irqsave(&p9_poll_lock, flags); + if (list_empty(&m->poll_pending_link)) + list_add_tail(&m->poll_pending_link, &p9_poll_pending_list); + spin_unlock_irqrestore(&p9_poll_lock, flags); + + /* perform the default wake up operation */ + return default_wake_function(&dummy_wait, mode, sync, key); +} + /** * p9_pollwait - add poll task to the wait queue * @filp: file pointer being polled @@ -476,29 +379,32 @@ static void p9_conn_destroy(struct p9_conn *m) static void p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p) { + struct p9_conn *m = container_of(p, struct p9_conn, pt); + struct p9_poll_wait *pwait = NULL; 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) + for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) { + if (m->poll_wait[i].wait_addr == NULL) { + pwait = &m->poll_wait[i]; break; + } + } - if (i >= ARRAY_SIZE(m->poll_waddr)) { + if (!pwait) { 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); + pwait->wait_addr = ERR_PTR(-EIO); return; } - init_waitqueue_entry(&m->poll_wait[i], m->poll_task->task); - add_wait_queue(wait_address, &m->poll_wait[i]); + pwait->conn = m; + pwait->wait_addr = wait_address; + init_waitqueue_func_entry(&pwait->wait, p9_pollwake); + add_wait_queue(wait_address, &pwait->wait); } /** @@ -553,23 +459,34 @@ static void p9_poll_mux(struct p9_conn *m) static int p9_poll_proc(void *a) { - struct p9_conn *m, *mtmp; - struct p9_mux_poll_task *vpt; + unsigned long flags; - vpt = a; - P9_DPRINTK(P9_DEBUG_MUX, "start %p %p\n", current, vpt); - while (!kthread_should_stop()) { - set_current_state(TASK_INTERRUPTIBLE); + P9_DPRINTK(P9_DEBUG_MUX, "start %p\n", current); + repeat: + spin_lock_irqsave(&p9_poll_lock, flags); + while (!list_empty(&p9_poll_pending_list)) { + struct p9_conn *conn = list_first_entry(&p9_poll_pending_list, + struct p9_conn, + poll_pending_link); + list_del_init(&conn->poll_pending_link); + spin_unlock_irqrestore(&p9_poll_lock, flags); - list_for_each_entry_safe(m, mtmp, &vpt->mux_list, mux_list) { - p9_poll_mux(m); - } + p9_poll_mux(conn); - P9_DPRINTK(P9_DEBUG_MUX, "sleeping...\n"); - schedule_timeout(SCHED_TIMEOUT * HZ); + spin_lock_irqsave(&p9_poll_lock, flags); } + spin_unlock_irqrestore(&p9_poll_lock, flags); + set_current_state(TASK_INTERRUPTIBLE); + if (list_empty(&p9_poll_pending_list)) { + P9_DPRINTK(P9_DEBUG_MUX, "sleeping...\n"); + schedule(); + } __set_current_state(TASK_RUNNING); + + if (!kthread_should_stop()) + goto repeat; + P9_DPRINTK(P9_DEBUG_MUX, "finish\n"); return 0; } @@ -1602,17 +1519,19 @@ static struct p9_trans_module p9_fd_trans = { int p9_trans_fd_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; } + p9_poll_task = kthread_run(p9_poll_proc, NULL, "v9fs-poll"); + if (IS_ERR(p9_poll_task)) { + destroy_workqueue(p9_mux_wq); + printk(KERN_WARNING "v9fs: mux: creating poll task failed\n"); + return PTR_ERR(p9_poll_task); + } + v9fs_register_trans(&p9_tcp_trans); v9fs_register_trans(&p9_unix_trans); v9fs_register_trans(&p9_fd_trans); @@ -1622,6 +1541,7 @@ int p9_trans_fd_init(void) void p9_trans_fd_exit(void) { + kthread_stop(p9_poll_task); v9fs_unregister_trans(&p9_tcp_trans); v9fs_unregister_trans(&p9_unix_trans); v9fs_unregister_trans(&p9_fd_trans); |
