pci: write file size to inode on proc bus file write

When a /proc/bus/pci file is written to, the size of that PCI device's
configuration space must be written to the inode.  Otherwise, it is
possible for the file to specify a size of 0 on stat if a task is holding
the same file open.
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/pci/proc.c

@@ -129,7 +129,7 @@ proc_bus_pci_read(struct file *file, char __user *buf, size_t nbytes, loff_t *pp
 static ssize_t
 proc_bus_pci_write(struct file *file, const char __user *buf, size_t nbytes, loff_t *ppos)
 {
-	const struct inode *ino = file->f_path.dentry->d_inode;
+	struct inode *ino = file->f_path.dentry->d_inode;
 	const struct proc_dir_entry *dp = PDE(ino);
 	struct pci_dev *dev = dp->data;
 	int pos = *ppos;
@@ -193,6 +193,7 @@ proc_bus_pci_write(struct file *file, const char __user *buf, size_t nbytes, lof
 	}
 
 	*ppos = pos;
+	i_size_write(ino, dp->size);
 	return nbytes;
 }