ANDROID: sdcardfs: Use per mount permissions
This switches sdcardfs over to using permission2.
Instead of mounting several sdcardfs instances onto
the same underlaying directory, you bind mount a
single mount several times, and remount with the
options you want. These are stored in the private
mount data, allowing you to maintain the same tree,
but have different permissions for different mount
points.
Warning functions have been added for permission,
as it should never be called, and the correct
behavior is unclear.
Change-Id: I841b1d70ec60cf2b866fa48edeb74a0b0f8334f5
Signed-off-by: Daniel Rosenberg <drosen@google.com>
diff --git a/fs/sdcardfs/derived_perm.c b/fs/sdcardfs/derived_perm.c
index 89daf69..066edbb 100644
--- a/fs/sdcardfs/derived_perm.c
+++ b/fs/sdcardfs/derived_perm.c
@@ -141,13 +141,23 @@ void fixup_perms_recursive(struct dentry *dentry, const char* name, size_t len)
info = SDCARDFS_I(d_inode(dentry));
if (needs_fixup(info->perm)) {
+ /* We need permission to fix up these values.
+ * Since permissions are based of of the mount, and
+ * we are accessing without the mount point, we create
+ * a fake mount with the permissions we will be using.
+ */
+ struct vfsmount fakemnt;
+ struct sdcardfs_vfsmount_options opts;
+ fakemnt.data = &opts;
+ opts.gid = AID_SDCARD_RW;
+ opts.mask = 0;
mutex_lock(&d_inode(dentry)->i_mutex);
- child = lookup_one_len(name, dentry, len);
+ child = lookup_one_len2(name, &fakemnt, dentry, len);
mutex_unlock(&d_inode(dentry)->i_mutex);
if (!IS_ERR(child)) {
- if (child->d_inode) {
+ if (d_inode(child)) {
get_derived_permission(dentry, child);
- fix_derived_permission(d_inode(child));
+ fixup_tmp_permissions(d_inode(child));
}
dput(child);
}
@@ -172,7 +182,7 @@ void fixup_top_recursive(struct dentry *parent) {
if (d_inode(dentry)) {
if (SDCARDFS_I(d_inode(parent))->top != SDCARDFS_I(d_inode(dentry))->top) {
get_derived_permission(parent, dentry);
- fix_derived_permission(d_inode(dentry));
+ fixup_tmp_permissions(d_inode(dentry));
fixup_top_recursive(dentry);
}
}
@@ -202,7 +212,7 @@ inline void update_derived_permission_lock(struct dentry *dentry)
dput(parent);
}
}
- fix_derived_permission(dentry->d_inode);
+ fixup_tmp_permissions(d_inode(dentry));
}
int need_graft_path(struct dentry *dentry)