fasync: re-organize fasync entry insertion to allow it under a spinlock
[pandora-kernel.git] / fs / locks.c
index 8b2b6ad..85fd9ce 100644 (file)
@@ -162,10 +162,11 @@ EXPORT_SYMBOL_GPL(unlock_flocks);
 static struct kmem_cache *filelock_cache __read_mostly;
 
 /* Allocate an empty lock structure. */
-static struct file_lock *locks_alloc_lock(void)
+struct file_lock *locks_alloc_lock(void)
 {
        return kmem_cache_alloc(filelock_cache, GFP_KERNEL);
 }
+EXPORT_SYMBOL_GPL(locks_alloc_lock);
 
 void locks_release_private(struct file_lock *fl)
 {
@@ -1365,7 +1366,6 @@ int fcntl_getlease(struct file *filp)
 int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
 {
        struct file_lock *fl, **before, **my_before = NULL, *lease;
-       struct file_lock *new_fl = NULL;
        struct dentry *dentry = filp->f_path.dentry;
        struct inode *inode = dentry->d_inode;
        int error, rdlease_count = 0, wrlease_count = 0;
@@ -1385,11 +1385,6 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
        lease = *flp;
 
        if (arg != F_UNLCK) {
-               error = -ENOMEM;
-               new_fl = locks_alloc_lock();
-               if (new_fl == NULL)
-                       goto out;
-
                error = -EAGAIN;
                if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0))
                        goto out;
@@ -1434,7 +1429,6 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
                goto out;
        }
 
-       error = 0;
        if (arg == F_UNLCK)
                goto out;
 
@@ -1442,15 +1436,11 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
        if (!leases_enable)
                goto out;
 
-       locks_copy_lock(new_fl, lease);
-       locks_insert_lock(before, new_fl);
-
-       *flp = new_fl;
+       locks_insert_lock(before, lease);
        return 0;
 
 out:
-       if (new_fl != NULL)
-               locks_free_lock(new_fl);
+       locks_free_lock(lease);
        return error;
 }
 EXPORT_SYMBOL(generic_setlease);
@@ -1514,26 +1504,38 @@ EXPORT_SYMBOL_GPL(vfs_setlease);
  */
 int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
 {
-       struct file_lock fl, *flp = &fl;
+       struct file_lock *fl;
+       struct fasync_struct *new;
        struct inode *inode = filp->f_path.dentry->d_inode;
        int error;
 
-       locks_init_lock(&fl);
-       error = lease_init(filp, arg, &fl);
-       if (error)
-               return error;
+       fl = lease_alloc(filp, arg);
+       if (IS_ERR(fl))
+               return PTR_ERR(fl);
 
+       new = fasync_alloc();
+       if (!new) {
+               locks_free_lock(fl);
+               return -ENOMEM;
+       }
        lock_flocks();
-
-       error = __vfs_setlease(filp, arg, &flp);
+       error = __vfs_setlease(filp, arg, &fl);
        if (error || arg == F_UNLCK)
                goto out_unlock;
 
-       error = fasync_helper(fd, filp, 1, &flp->fl_fasync);
+       /*
+        * fasync_insert_entry() returns the old entry if any.
+        * If there was no old entry, then it used 'new' and
+        * inserted it into the fasync list. Clear new so that
+        * we don't release it here.
+        */
+       if (!fasync_insert_entry(fd, filp, &fl->fl_fasync, new))
+               new = NULL;
+
        if (error < 0) {
                /* remove lease just inserted by setlease */
-               flp->fl_type = F_UNLCK | F_INPROGRESS;
-               flp->fl_break_time = jiffies - 10;
+               fl->fl_type = F_UNLCK | F_INPROGRESS;
+               fl->fl_break_time = jiffies - 10;
                time_out_leases(inode);
                goto out_unlock;
        }
@@ -1541,6 +1543,8 @@ int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
        error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0);
 out_unlock:
        unlock_flocks();
+       if (new)
+               fasync_free(new);
        return error;
 }