linux-kernel - [PATCH 19/67] cachefiles: Don't set an xattr on the root of the cache

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Date:   Mon, 18 Oct 2021 15:55:33 +0100
From:   David Howells <dhowells@...hat.com>
To:     linux-cachefs@...hat.com
Cc:     dhowells@...hat.com, Trond Myklebust <trondmy@...merspace.com>,
        Anna Schumaker <anna.schumaker@...app.com>,
        Steve French <sfrench@...ba.org>,
        Dominique Martinet <asmadeus@...ewreck.org>,
        Jeff Layton <jlayton@...hat.com>,
        Matthew Wilcox <willy@...radead.org>,
        Alexander Viro <viro@...iv.linux.org.uk>,
        Omar Sandoval <osandov@...ndov.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        linux-afs@...ts.infradead.org, linux-nfs@...r.kernel.org,
        linux-cifs@...r.kernel.org, ceph-devel@...r.kernel.org,
        v9fs-developer@...ts.sourceforge.net,
        linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 19/67] cachefiles: Don't set an xattr on the root of the cache

cachefiles_check_object_type() sets an xattr on the root of the cache, but
it's pointless because it never conveys any useful information, so don't do
that.

Signed-off-by: David Howells <dhowells@...hat.com>
---

 fs/cachefiles/bind.c     |    4 --
 fs/cachefiles/internal.h |    1 -
 fs/cachefiles/xattr.c    |   76 ----------------------------------------------
 3 files changed, 81 deletions(-)

diff --git a/fs/cachefiles/bind.c b/fs/cachefiles/bind.c
index d463d89f5db8..6720c07f3d85 100644
--- a/fs/cachefiles/bind.c
+++ b/fs/cachefiles/bind.c
@@ -199,10 +199,6 @@ static int cachefiles_daemon_add_cache(struct cachefiles_cache *cache)
 	fsdef->dentry = cachedir;
 	fsdef->fscache.cookie = NULL;
 
-	ret = cachefiles_check_object_type(fsdef);
-	if (ret < 0)
-		goto error_unsupported;
-
 	/* get the graveyard directory */
 	graveyard = cachefiles_get_directory(cache, root, "graveyard");
 	if (IS_ERR(graveyard)) {
diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index 0515add2b7e8..6464a6821bfb 100644
--- a/fs/cachefiles/internal.h
+++ b/fs/cachefiles/internal.h
@@ -169,7 +169,6 @@ static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
 /*
  * xattr.c
  */
-extern int cachefiles_check_object_type(struct cachefiles_object *object);
 extern int cachefiles_set_object_xattr(struct cachefiles_object *object,
 				       unsigned int xattr_flags);
 extern int cachefiles_check_auxdata(struct cachefiles_object *object);
diff --git a/fs/cachefiles/xattr.c b/fs/cachefiles/xattr.c
index bcc4a2dfe1e8..8b9f30f9ce21 100644
--- a/fs/cachefiles/xattr.c
+++ b/fs/cachefiles/xattr.c
@@ -23,82 +23,6 @@ struct cachefiles_xattr {
 static const char cachefiles_xattr_cache[] =
 	XATTR_USER_PREFIX "CacheFiles.cache";
 
-/*
- * check the type label on an object
- * - done using xattrs
- */
-int cachefiles_check_object_type(struct cachefiles_object *object)
-{
-	struct dentry *dentry = object->dentry;
-	char type[3], xtype[3];
-	int ret;
-
-	ASSERT(dentry);
-	ASSERT(d_backing_inode(dentry));
-
-	if (!object->fscache.cookie)
-		strcpy(type, "C3");
-	else
-		snprintf(type, 3, "%02x", object->fscache.cookie->type);
-
-	_enter("%x{%s}", object->fscache.debug_id, type);
-
-	/* attempt to install a type label directly */
-	ret = vfs_setxattr(&init_user_ns, dentry, cachefiles_xattr_cache, type,
-			   2, XATTR_CREATE);
-	if (ret == 0) {
-		_debug("SET"); /* we succeeded */
-		goto error;
-	}
-
-	if (ret != -EEXIST) {
-		pr_err("Can't set xattr on %pd [%lu] (err %d)\n",
-		       dentry, d_backing_inode(dentry)->i_ino,
-		       -ret);
-		goto error;
-	}
-
-	/* read the current type label */
-	ret = vfs_getxattr(&init_user_ns, dentry, cachefiles_xattr_cache, xtype,
-			   3);
-	if (ret < 0) {
-		if (ret == -ERANGE)
-			goto bad_type_length;
-
-		pr_err("Can't read xattr on %pd [%lu] (err %d)\n",
-		       dentry, d_backing_inode(dentry)->i_ino,
-		       -ret);
-		goto error;
-	}
-
-	/* check the type is what we're expecting */
-	if (ret != 2)
-		goto bad_type_length;
-
-	if (xtype[0] != type[0] || xtype[1] != type[1])
-		goto bad_type;
-
-	ret = 0;
-
-error:
-	_leave(" = %d", ret);
-	return ret;
-
-bad_type_length:
-	pr_err("Cache object %lu type xattr length incorrect\n",
-	       d_backing_inode(dentry)->i_ino);
-	ret = -EIO;
-	goto error;
-
-bad_type:
-	xtype[2] = 0;
-	pr_err("Cache object %pd [%lu] type %s not %s\n",
-	       dentry, d_backing_inode(dentry)->i_ino,
-	       xtype, type);
-	ret = -EIO;
-	goto error;
-}
-
 /*
  * set the state xattr on a cache file
  */