[PATCH] spufs: dont hold root->isem in spu_forget

spu_forget will do mmput on the DMA address space,
which can lead to lots of other stuff getting triggered.
We better not hold a semaphore here that we might
need in the process.

Noticed by Al Viro.

Signed-off-by: Arnd Bergmann <arndb@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c
index 2c3ba4e..4594401 100644 (file)
--- a/arch/powerpc/platforms/cell/spufs/inode.c
+++ b/arch/powerpc/platforms/cell/spufs/inode.c
@@ -162,10 +162,10 @@ static int spufs_rmdir(struct inode *root, struct dentry *dir_dentry)
 {
        struct dentry *dentry, *tmp;
        struct spu_context *ctx;
-       int err;
 
        /* remove all entries */
-       err = 0;
+       down(&root->i_sem);
+       down(&dir_dentry->d_inode->i_sem);
        list_for_each_entry_safe(dentry, tmp, &dir_dentry->d_subdirs, d_child) {
                spin_lock(&dcache_lock);
                spin_lock(&dentry->d_lock);
@@ -181,16 +181,16 @@ static int spufs_rmdir(struct inode *root, struct dentry *dir_dentry)
                        spin_unlock(&dcache_lock);
                }
        }
+       shrink_dcache_parent(dir_dentry);
+       up(&dir_dentry->d_inode->i_sem);
+       up(&root->i_sem);
 
        /* We have to give up the mm_struct */
        ctx = SPUFS_I(dir_dentry->d_inode)->i_ctx;
        spu_forget(ctx);
 
-       if (!err) {
-               shrink_dcache_parent(dir_dentry);
-               err = simple_rmdir(root, dir_dentry);
-       }
-       return err;
+       /* XXX Do we need to hold i_sem here ? */
+       return simple_rmdir(root, dir_dentry);
 }
 
 static int spufs_dir_close(struct inode *inode, struct file *file)
@@ -201,10 +201,10 @@ static int spufs_dir_close(struct inode *inode, struct file *file)
 
        dentry = file->f_dentry;
        dir = dentry->d_parent->d_inode;
-       down(&dir->i_sem);
-       ret = spufs_rmdir(dir, file->f_dentry);
+
+       ret = spufs_rmdir(dir, dentry);
        WARN_ON(ret);
-       up(&dir->i_sem);
+
        return dcache_dir_close(inode, file);
 }