coda: cleanup /dev/cfs open and close handling

- Make sure device index is not a negative number.
- Unlink queued requests when the device is closed to avoid passing them
  to the next opener.

Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 30 insertions, 31 deletions

diff --git a/fs/coda/psdev.c b/fs/coda/psdev.c
index 09382d47a4e1..6818c20372ca 100644
--- a/fs/coda/psdev.c
+++ b/fs/coda/psdev.c
@@ -272,56 +272,51 @@ out:
 
 static int coda_psdev_open(struct inode * inode, struct file * file)
 {
-        struct venus_comm *vcp;
-        int idx;
+        struct venus_comm *vcp;
+        int idx, err;
 
-        lock_kernel();
         idx = iminor(inode);
-        if(idx >= MAX_CODADEVS) {
-                unlock_kernel();
+        if (idx < 0 || idx >= MAX_CODADEVS)
                 return -ENODEV;
-        }
 
+        lock_kernel();
+
+        err = -EBUSY;
         vcp = &coda_comms[idx];
-        if(vcp->vc_inuse) {
-                unlock_kernel();
-                return -EBUSY;
-        }
-        
-        if (!vcp->vc_inuse++) {
+        if (!vcp->vc_inuse) {
+                vcp->vc_inuse++;
+
                 INIT_LIST_HEAD(&vcp->vc_pending);
                 INIT_LIST_HEAD(&vcp->vc_processing);
                 init_waitqueue_head(&vcp->vc_waitq);
                 vcp->vc_sb = NULL;
                 vcp->vc_seq = 0;
+
+                file->private_data = vcp;
+                err = 0;
         }
-        
-        file->private_data = vcp;
 
         unlock_kernel();
-        return 0;
+        return err;
 }
 
 
 static int coda_psdev_release(struct inode * inode, struct file * file)
 {
-        struct venus_comm *vcp = (struct venus_comm *) file->private_data;
-        struct upc_req *req, *tmp;
+        struct venus_comm *vcp = (struct venus_comm *) file->private_data;
+        struct upc_req *req, *tmp;
 
-        lock_kernel();
-        if ( !vcp->vc_inuse ) {
-                unlock_kernel();
+        if (!vcp || !vcp->vc_inuse ) {
                 printk("psdev_release: Not open.\n");
                 return -1;
         }
 
-        if (--vcp->vc_inuse) {
-                unlock_kernel();
-                return 0;
-        }
-        
-        /* Wakeup clients so they can return. */
+        lock_kernel();
+
+        /* Wakeup clients so they can return. */
         list_for_each_entry_safe(req, tmp, &vcp->vc_pending, uc_chain) {
+                list_del(&req->uc_chain);
+
                 /* Async requests need to be freed here */
                 if (req->uc_flags & REQ_ASYNC) {
                         CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
@@ -330,13 +325,17 @@ static int coda_psdev_release(struct inode * inode, struct file * file)
                 }
                 req->uc_flags |= REQ_ABORT;
                 wake_up(&req->uc_sleep);
-        }
-        
-        list_for_each_entry(req, &vcp->vc_processing, uc_chain) {
+        }
+
+        list_for_each_entry_safe(req, tmp, &vcp->vc_processing, uc_chain) {
+                list_del(&req->uc_chain);
+
                 req->uc_flags |= REQ_ABORT;
-                wake_up(&req->uc_sleep);
-        }
+                wake_up(&req->uc_sleep);
+        }
 
+        file->private_data = NULL;
+        vcp->vc_inuse--;
         unlock_kernel();
         return 0;
 }