Attachment 1084265 Details for Bug 1272868 – sample patch

[patch] sample patch

fs_subtype.patch (text/plain), 4.23 KB, created by Bipin Kunal on 2015-10-19 06:14:17 UTC

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Creator: Bipin Kunal

Created: 2015-10-19 06:14:17 UTC

Size: 4.23 KB

patch

obsolete

>diff --git a/fs/internal.h b/fs/internal.h
>index 71859c4d..cba4ebb 100644
>--- a/fs/internal.h
>+++ b/fs/internal.h
>@@ -85,7 +85,7 @@ extern struct file *get_empty_filp(void);
>  */
> extern int do_remount_sb(struct super_block *, int, void *, int);
> extern bool trylock_super(struct super_block *sb);
>-extern struct dentry *mount_fs(struct file_system_type *,
>+extern struct dentry *mount_fs(struct file_system_type *, const char *,
> 			       int, const char *, void *);
> extern struct super_block *user_get_super(dev_t);
> 
>diff --git a/fs/namespace.c b/fs/namespace.c
>index 0570729..e416461 100644
>--- a/fs/namespace.c
>+++ b/fs/namespace.c
>@@ -929,8 +929,9 @@ static struct mount *skip_mnt_tree(struct mount *p)
> 	return p;
> }
> 
>-struct vfsmount *
>-vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data)
>+static struct vfsmount *
>+vfs_kern_mount_subtype(struct file_system_type *type, const char *subtype,
>+		       int flags, const char *name, void *data)
> {
> 	struct mount *mnt;
> 	struct dentry *root;
>@@ -945,7 +946,7 @@ vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void
> 	if (flags & MS_KERNMOUNT)
> 		mnt->mnt.mnt_flags = MNT_INTERNAL;
> 
>-	root = mount_fs(type, flags, name, data);
>+	root = mount_fs(type, subtype, flags, name, data);
> 	if (IS_ERR(root)) {
> 		mnt_free_id(mnt);
> 		free_vfsmnt(mnt);
>@@ -961,6 +962,12 @@ vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void
> 	unlock_mount_hash();
> 	return &mnt->mnt;
> }
>+
>+struct vfsmount *
>+vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data)
>+{
>+	return vfs_kern_mount_subtype(type, NULL, flags, name, data);
>+}
> EXPORT_SYMBOL_GPL(vfs_kern_mount);
> 
> static struct mount *clone_mnt(struct mount *old, struct dentry *root,
>@@ -2300,27 +2307,17 @@ out:
> 	return err;
> }
> 
>-static struct vfsmount *fs_set_subtype(struct vfsmount *mnt, const char *fstype)
>+static const char *fs_get_subtype(const char *fstype)
> {
>-	int err;
> 	const char *subtype = strchr(fstype, '.');
>+
> 	if (subtype) {
> 		subtype++;
>-		err = -EINVAL;
> 		if (!subtype[0])
>-			goto err;
>-	} else
>-		subtype = "";
>-
>-	mnt->mnt_sb->s_subtype = kstrdup(subtype, GFP_KERNEL);
>-	err = -ENOMEM;
>-	if (!mnt->mnt_sb->s_subtype)
>-		goto err;
>-	return mnt;
>+			return ERR_PTR(-EINVAL);
>+	}
> 
>- err:
>-	mntput(mnt);
>-	return ERR_PTR(err);
>+	return subtype;
> }
> 
> /*
>@@ -2380,6 +2377,7 @@ static int do_new_mount(struct path *path, const char *fstype, int flags,
> 	struct user_namespace *user_ns = current->nsproxy->mnt_ns->user_ns;
> 	struct vfsmount *mnt;
> 	int err;
>+	const char *subtype = NULL;
> 
> 	if (!fstype)
> 		return -EINVAL;
>@@ -2406,10 +2404,16 @@ static int do_new_mount(struct path *path, const char *fstype, int flags,
> 		}
> 	}
> 
>-	mnt = vfs_kern_mount(type, flags, name, data);
>-	if (!IS_ERR(mnt) && (type->fs_flags & FS_HAS_SUBTYPE) &&
>-	    !mnt->mnt_sb->s_subtype)
>-		mnt = fs_set_subtype(mnt, fstype);
>+	if (type->fs_flags & FS_HAS_SUBTYPE) {
>+		subtype = fs_get_subtype(fstype);
>+		if (IS_ERR(subtype)) {
>+			put_filesystem(type);
>+			return PTR_ERR(subtype);
>+		} else if (!subtype)
>+			subtype = "";
>+	}
>+
>+	mnt = vfs_kern_mount_subtype(type, subtype, flags, name, data);
> 
> 	put_filesystem(type);
> 	if (IS_ERR(mnt))
>diff --git a/fs/super.c b/fs/super.c
>index 954aeb8..c9e9998 100644
>--- a/fs/super.c
>+++ b/fs/super.c
>@@ -1103,7 +1103,8 @@ 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, const char *subtype, int flags,
>+	 const char *name, void *data)
> {
> 	struct dentry *root;
> 	struct super_block *sb;
>@@ -1130,6 +1131,14 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
> 	WARN_ON(!sb->s_bdi);
> 	sb->s_flags |= MS_BORN;
> 
>+	/* selinux requires the subtype to make policy decisions */
>+	if (subtype && !sb->s_subtype) {
>+		error = -ENOMEM;
>+		sb->s_subtype = kstrdup(subtype, GFP_KERNEL);
>+		if (!sb->s_subtype)
>+			goto out_sb;
>+	}
>+
> 	error = security_sb_kern_mount(sb, flags, secdata);
> 	if (error)
> 		goto out_sb;

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Attachments on bug 1272868: 1084265