[PATCH] v9fs: handle kthread_create failure, minor bugfixes

- remove unnecessary -ENOMEM assignments
- return correct value when buf_check_size for second time in a buffer
- handle failures when create_workqueue and kthread_create are called
- use kzalloc instead of kmalloc/memset 0
- v9fs_str_copy and v9fs_str_compare were buggy, were used only in one
  place, correct the logic and move it to the place it is used.

Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 26 insertions, 12 deletions

diff --git a/fs/9p/mux.c b/fs/9p/mux.c
index f21cf5083973..945cb368d451 100644
--- a/fs/9p/mux.c
+++ b/fs/9p/mux.c
@@ -102,8 +102,6 @@ struct v9fs_mux_rpc {
         wait_queue_head_t wqueue;
 };
 
-extern int v9fs_errstr2errno(char *str, int len);
-
 static int v9fs_poll_proc(void *);
 static void v9fs_read_work(void *);
 static void v9fs_write_work(void *);
@@ -119,7 +117,7 @@ static int v9fs_mux_num;
 static int v9fs_mux_poll_task_num;
 static struct v9fs_mux_poll_task v9fs_mux_poll_tasks[100];
 
-void v9fs_mux_global_init(void)
+int v9fs_mux_global_init(void)
 {
         int i;
 
@@ -127,6 +125,10 @@ void v9fs_mux_global_init(void)
                 v9fs_mux_poll_tasks[i].task = NULL;
 
         v9fs_mux_wq = create_workqueue("v9fs");
+        if (!v9fs_mux_wq)
+                return -ENOMEM;
+
+        return 0;
 }
 
 void v9fs_mux_global_exit(void)
@@ -156,10 +158,11 @@ inline int v9fs_mux_calc_poll_procs(int muxnum)
         return n;
 }
 
-static void v9fs_mux_poll_start(struct v9fs_mux_data *m)
+static int v9fs_mux_poll_start(struct v9fs_mux_data *m)
 {
         int i, n;
         struct v9fs_mux_poll_task *vpt, *vptlast;
+        struct task_struct *pproc;
 
         dprintk(DEBUG_MUX, "mux %p muxnum %d procnum %d\n", m, v9fs_mux_num,
                 v9fs_mux_poll_task_num);
@@ -171,13 +174,16 @@ static void v9fs_mux_poll_start(struct v9fs_mux_data *m)
                         if (v9fs_mux_poll_tasks[i].task == NULL) {
                                 vpt = &v9fs_mux_poll_tasks[i];
                                 dprintk(DEBUG_MUX, "create proc %p\n", vpt);
-                                vpt->task =
-                                    kthread_create(v9fs_poll_proc, vpt,
+                                pproc = kthread_create(v9fs_poll_proc, vpt,
                                                    "v9fs-poll");
-                                INIT_LIST_HEAD(&vpt->mux_list);
-                                vpt->muxnum = 0;
-                                v9fs_mux_poll_task_num++;
-                                wake_up_process(vpt->task);
+
+                                if (!IS_ERR(pproc)) {
+                                        vpt->task = pproc;
+                                        INIT_LIST_HEAD(&vpt->mux_list);
+                                        vpt->muxnum = 0;
+                                        v9fs_mux_poll_task_num++;
+                                        wake_up_process(vpt->task);
+                                }
                                 break;
                         }
                 }
@@ -207,16 +213,21 @@ static void v9fs_mux_poll_start(struct v9fs_mux_data *m)
         }
 
         if (i >= ARRAY_SIZE(v9fs_mux_poll_tasks)) {
+                if (vptlast == NULL)
+                        return -ENOMEM;
+
                 dprintk(DEBUG_MUX, "put in proc %d\n", i);
                 list_add(&m->mux_list, &vptlast->mux_list);
                 vptlast->muxnum++;
-                m->poll_task = vpt;
+                m->poll_task = vptlast;
                 memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
                 init_poll_funcptr(&m->pt, v9fs_pollwait);
         }
 
         v9fs_mux_num++;
         down(&v9fs_mux_task_lock);
+
+        return 0;
 }
 
 static void v9fs_mux_poll_stop(struct v9fs_mux_data *m)
@@ -283,7 +294,10 @@ struct v9fs_mux_data *v9fs_mux_init(struct v9fs_transport *trans, int msize,
         INIT_WORK(&m->wq, v9fs_write_work, m);
         m->wsched = 0;
         memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
-        v9fs_mux_poll_start(m);
+        m->poll_task = NULL;
+        n = v9fs_mux_poll_start(m);
+        if (n)
+                return ERR_PTR(n);
 
         n = trans->poll(trans, &m->pt);
         if (n & POLLIN) {