[S390] hypfs: Move buffer allocation from open to read
Currently the buffer for diagnose data is allocated in the open function
of the debugfs file and is released in the close function. This has the
drawback that a user (root) can pin that memory by not closing the file.
This patch moves the buffer allocation to the read function. The buffer is
automatically released after the buffer is copied to userspace.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/hypfs/inode.c b/arch/s390/hypfs/inode.c
index 47cc446..6fe874f 100644
--- a/arch/s390/hypfs/inode.c
+++ b/arch/s390/hypfs/inode.c
@@ -46,8 +46,6 @@
/* start of list of all dentries, which have to be deleted on update */
static struct dentry *hypfs_last_dentry;
-struct dentry *hypfs_dbfs_dir;
-
static void hypfs_update_update(struct super_block *sb)
{
struct hypfs_sb_info *sb_info = sb->s_fs_info;
@@ -471,13 +469,12 @@
{
int rc;
- hypfs_dbfs_dir = debugfs_create_dir("s390_hypfs", NULL);
- if (IS_ERR(hypfs_dbfs_dir))
- return PTR_ERR(hypfs_dbfs_dir);
-
+ rc = hypfs_dbfs_init();
+ if (rc)
+ return rc;
if (hypfs_diag_init()) {
rc = -ENODATA;
- goto fail_debugfs_remove;
+ goto fail_dbfs_exit;
}
if (hypfs_vm_init()) {
rc = -ENODATA;
@@ -499,9 +496,8 @@
hypfs_vm_exit();
fail_hypfs_diag_exit:
hypfs_diag_exit();
-fail_debugfs_remove:
- debugfs_remove(hypfs_dbfs_dir);
-
+fail_dbfs_exit:
+ hypfs_dbfs_exit();
pr_err("Initialization of hypfs failed with rc=%i\n", rc);
return rc;
}
@@ -510,7 +506,7 @@
{
hypfs_diag_exit();
hypfs_vm_exit();
- debugfs_remove(hypfs_dbfs_dir);
+ hypfs_dbfs_exit();
unregister_filesystem(&hypfs_type);
kobject_put(s390_kobj);
}