ANDROID: vfs: Allow filesystems to access their private mount data
Now we pass the vfsmount when mounting and remounting.
This allows the filesystem to actually set up the mount
specific data, although we can't quite do anything with
it yet. show_options is expanded to include data that
lives with the mount.
To avoid changing existing filesystems, these have
been added as new vfs functions.
Change-Id: If80670bfad9f287abb8ac22457e1b034c9697097
Signed-off-by: Daniel Rosenberg <drosen@google.com>
diff --git a/fs/super.c b/fs/super.c
index 417d548..5dcfc79 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -800,7 +800,8 @@ struct super_block *user_get_super(dev_t dev)
}
/**
- * do_remount_sb - asks filesystem to change mount options.
+ * do_remount_sb2 - asks filesystem to change mount options.
+ * @mnt: mount we are looking at
* @sb: superblock in question
* @sb_flags: revised superblock flags
* @data: the rest of options
@@ -808,7 +809,7 @@ struct super_block *user_get_super(dev_t dev)
*
* Alters the mount options of a mounted file system.
*/
-int do_remount_sb(struct super_block *sb, int sb_flags, void *data, int force)
+int do_remount_sb2(struct vfsmount *mnt, struct super_block *sb, int sb_flags, void *data, int force)
{
int retval;
int remount_ro;
@@ -850,7 +851,16 @@ int do_remount_sb(struct super_block *sb, int sb_flags, void *data, int force)
}
}
- if (sb->s_op->remount_fs) {
+ if (mnt && sb->s_op->remount_fs2) {
+ retval = sb->s_op->remount_fs2(mnt, sb, &sb_flags, data);
+ if (retval) {
+ if (!force)
+ goto cancel_readonly;
+ /* If forced remount, go ahead despite any errors */
+ WARN(1, "forced remount of a %s fs returned %i\n",
+ sb->s_type->name, retval);
+ }
+ } else if (sb->s_op->remount_fs) {
retval = sb->s_op->remount_fs(sb, &sb_flags, data);
if (retval) {
if (!force)
@@ -882,6 +892,11 @@ int do_remount_sb(struct super_block *sb, int sb_flags, void *data, int force)
return retval;
}
+int do_remount_sb(struct super_block *sb, int flags, void *data, int force)
+{
+ return do_remount_sb2(NULL, sb, flags, data, force);
+}
+
static void do_emergency_remount(struct work_struct *work)
{
struct super_block *sb, *p = NULL;
@@ -1203,7 +1218,7 @@ struct dentry *mount_single(struct file_system_type *fs_type,
EXPORT_SYMBOL(mount_single);
struct dentry *
-mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
+mount_fs(struct file_system_type *type, int flags, const char *name, struct vfsmount *mnt, void *data)
{
struct dentry *root;
struct super_block *sb;
@@ -1220,7 +1235,10 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
goto out_free_secdata;
}
- root = type->mount(type, flags, name, data);
+ if (type->mount2)
+ root = type->mount2(mnt, type, flags, name, data);
+ else
+ root = type->mount(type, flags, name, data);
if (IS_ERR(root)) {
error = PTR_ERR(root);
goto out_free_secdata;