Coda: replace BKL with mutex

Replace the BKL with a mutex to protect the venus_comm structure which
binds the mountpoint with the character device and holds the upcall
queues.

Signed-off-by: Yoshihisa Abe <yoshiabe@cs.cmu.edu>
Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 17 insertions, 11 deletions

diff --git a/fs/coda/psdev.c b/fs/coda/psdev.c
index 9a9248e632c6..62647a8595e4 100644
--- a/fs/coda/psdev.c
+++ b/fs/coda/psdev.c
@@ -35,7 +35,7 @@
 #include <linux/poll.h>
 #include <linux/init.h>
 #include <linux/list.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/device.h>
 #include <asm/io.h>
 #include <asm/system.h>
@@ -67,8 +67,10 @@ static unsigned int coda_psdev_poll(struct file *file, poll_table * wait)
         unsigned int mask = POLLOUT | POLLWRNORM;
 
         poll_wait(file, &vcp->vc_waitq, wait);
+        mutex_lock(&vcp->vc_mutex);
         if (!list_empty(&vcp->vc_pending))
                 mask |= POLLIN | POLLRDNORM;
+        mutex_unlock(&vcp->vc_mutex);
 
         return mask;
 }
@@ -143,7 +145,7 @@ static ssize_t coda_psdev_write(struct file *file, const char __user *buf,
         }
         
         /* Look for the message on the processing queue. */
-        lock_kernel();
+        mutex_lock(&vcp->vc_mutex);
         list_for_each(lh, &vcp->vc_processing) {
                 tmp = list_entry(lh, struct upc_req , uc_chain);
                 if (tmp->uc_unique == hdr.unique) {
@@ -152,7 +154,7 @@ static ssize_t coda_psdev_write(struct file *file, const char __user *buf,
                         break;
                 }
         }
-        unlock_kernel();
+        mutex_unlock(&vcp->vc_mutex);
 
         if (!req) {
                 printk("psdev_write: msg (%d, %d) not found\n", 
@@ -207,7 +209,7 @@ static ssize_t coda_psdev_read(struct file * file, char __user * buf,
         if (nbytes == 0)
                 return 0;
 
-        lock_kernel();
+        mutex_lock(&vcp->vc_mutex);
 
         add_wait_queue(&vcp->vc_waitq, &wait);
         set_current_state(TASK_INTERRUPTIBLE);
@@ -221,7 +223,9 @@ static ssize_t coda_psdev_read(struct file * file, char __user * buf,
                         retval = -ERESTARTSYS;
                         break;
                 }
+                mutex_unlock(&vcp->vc_mutex);
                 schedule();
+                mutex_lock(&vcp->vc_mutex);
         }
 
         set_current_state(TASK_RUNNING);
@@ -254,7 +258,7 @@ static ssize_t coda_psdev_read(struct file * file, char __user * buf,
         CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
         kfree(req);
 out:
-        unlock_kernel();
+        mutex_unlock(&vcp->vc_mutex);
         return (count ? count : retval);
 }
 
@@ -267,10 +271,10 @@ static int coda_psdev_open(struct inode * inode, struct file * file)
         if (idx < 0 || idx >= MAX_CODADEVS)
                 return -ENODEV;
 
-        lock_kernel();
-
         err = -EBUSY;
         vcp = &coda_comms[idx];
+        mutex_lock(&vcp->vc_mutex);
+
         if (!vcp->vc_inuse) {
                 vcp->vc_inuse++;
 
@@ -284,7 +288,7 @@ static int coda_psdev_open(struct inode * inode, struct file * file)
                 err = 0;
         }
 
-        unlock_kernel();
+        mutex_unlock(&vcp->vc_mutex);
         return err;
 }
 
@@ -299,7 +303,7 @@ static int coda_psdev_release(struct inode * inode, struct file * file)
                 return -1;
         }
 
-        lock_kernel();
+        mutex_lock(&vcp->vc_mutex);
 
         /* Wakeup clients so they can return. */
         list_for_each_entry_safe(req, tmp, &vcp->vc_pending, uc_chain) {
@@ -324,7 +328,7 @@ static int coda_psdev_release(struct inode * inode, struct file * file)
 
         file->private_data = NULL;
         vcp->vc_inuse--;
-        unlock_kernel();
+        mutex_unlock(&vcp->vc_mutex);
         return 0;
 }
 
@@ -353,9 +357,11 @@ static int init_coda_psdev(void)
                 err = PTR_ERR(coda_psdev_class);
                 goto out_chrdev;
         }               
-        for (i = 0; i < MAX_CODADEVS; i++)
+        for (i = 0; i < MAX_CODADEVS; i++) {
+                mutex_init(&(&coda_comms[i])->vc_mutex);
                 device_create(coda_psdev_class, NULL,
                               MKDEV(CODA_PSDEV_MAJOR, i), NULL, "cfs%d", i);
+        }
         coda_sysctl_init();
         goto out;