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-rw-r--r--net/9p/trans_fd.c252
1 files changed, 86 insertions, 166 deletions
diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index 6dabbdb..f845923 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);
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