Merge tag 'afs-fixes-20210315' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull AFS fixes from David Howells:

 - Fix an oops in AFS that can be triggered by accessing one of the
   afs.yfs.* xattrs against an OpenAFS server - for instance by commands
   like "cp -a"[1], "rsync -X" or getfattr[2]. These try and copy all of
   the xattrs.

   cp and rsync should pay attention to the list in /etc/xattr.conf, but
   cp doesn't on Ubuntu and rsync doesn't seem to on Ubuntu or Fedora.
   xattr.conf has been modified upstream[3], and a new version has just
   been cut that includes it. I've logged a bug against rsync for the
   problem there[4].

 - Stop listing "afs.*" xattrs[5][6][7], but particularly ACL ones[8] so
   that they don't confuse cp and rsync.

   This removes them from the list returned by listxattr(), but they're
   still available to get/set.

Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003498.html [1]
Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003501.html [2]
Link: https://git.savannah.nongnu.org/cgit/attr.git/commit/?id=74da517cc655a82ded715dea7245ce88ebc91b98 [3]
Link: https://github.com/WayneD/rsync/issues/163 [4]
Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003516.html [5]
Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003524.html [6]
Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003565.html # v1
Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003568.html [7]
Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003570.html [8]
Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003571.html # v2

* tag 'afs-fixes-20210315' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Stop listxattr() from listing "afs.*" attributes
  afs: Fix accessing YFS xattrs on a non-YFS server

7 files changed, 12 insertions, 31 deletions

diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index 714fcca9af9909..17548c1faf0299 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -70,7 +70,6 @@ const struct inode_operations afs_dir_inode_operations = {
 	.permission	= afs_permission,
 	.getattr	= afs_getattr,
 	.setattr	= afs_setattr,
-	.listxattr	= afs_listxattr,
 };
 
 const struct address_space_operations afs_dir_aops = {
diff --git a/fs/afs/file.c b/fs/afs/file.c
index 85f5adf21aa08a..960b64268623e4 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -43,7 +43,6 @@ const struct inode_operations afs_file_inode_operations = {
 	.getattr	= afs_getattr,
 	.setattr	= afs_setattr,
 	.permission	= afs_permission,
-	.listxattr	= afs_listxattr,
 };
 
 const struct address_space_operations afs_fs_aops = {
diff --git a/fs/afs/fs_operation.c b/fs/afs/fs_operation.c
index 97cab12b0a6c25..71c58723763d23 100644
--- a/fs/afs/fs_operation.c
+++ b/fs/afs/fs_operation.c
@@ -181,10 +181,13 @@ void afs_wait_for_operation(struct afs_operation *op)
 		if (test_bit(AFS_SERVER_FL_IS_YFS, &op->server->flags) &&
 		    op->ops->issue_yfs_rpc)
 			op->ops->issue_yfs_rpc(op);
-		else
+		else if (op->ops->issue_afs_rpc)
 			op->ops->issue_afs_rpc(op);
+		else
+			op->ac.error = -ENOTSUPP;
 
-		op->error = afs_wait_for_call_to_complete(op->call, &op->ac);
+		if (op->call)
+			op->error = afs_wait_for_call_to_complete(op->call, &op->ac);
 	}
 
 	switch (op->error) {
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 1156b2df28d36a..12be88716e4c9b 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -27,7 +27,6 @@
 
 static const struct inode_operations afs_symlink_inode_operations = {
 	.get_link	= page_get_link,
-	.listxattr	= afs_listxattr,
 };
 
 static noinline void dump_vnode(struct afs_vnode *vnode, struct afs_vnode *parent_vnode)
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index b626e38e9ab5d8..1627b187281257 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -1509,7 +1509,6 @@ extern int afs_launder_page(struct page *);
  * xattr.c
  */
 extern const struct xattr_handler *afs_xattr_handlers[];
-extern ssize_t afs_listxattr(struct dentry *, char *, size_t);
 
 /*
  * yfsclient.c
diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c
index 052dab2f5c03a8..bbb2c210d139d9 100644
--- a/fs/afs/mntpt.c
+++ b/fs/afs/mntpt.c
@@ -32,7 +32,6 @@ const struct inode_operations afs_mntpt_inode_operations = {
 	.lookup		= afs_mntpt_lookup,
 	.readlink	= page_readlink,
 	.getattr	= afs_getattr,
-	.listxattr	= afs_listxattr,
 };
 
 const struct inode_operations afs_autocell_inode_operations = {
diff --git a/fs/afs/xattr.c b/fs/afs/xattr.c
index c629caae500286..7751b0b3f81d48 100644
--- a/fs/afs/xattr.c
+++ b/fs/afs/xattr.c
@@ -11,29 +11,6 @@
 #include <linux/xattr.h>
 #include "internal.h"
 
-static const char afs_xattr_list[] =
-	"afs.acl\0"
-	"afs.cell\0"
-	"afs.fid\0"
-	"afs.volume\0"
-	"afs.yfs.acl\0"
-	"afs.yfs.acl_inherited\0"
-	"afs.yfs.acl_num_cleaned\0"
-	"afs.yfs.vol_acl";
-
-/*
- * Retrieve a list of the supported xattrs.
- */
-ssize_t afs_listxattr(struct dentry *dentry, char *buffer, size_t size)
-{
-	if (size == 0)
-		return sizeof(afs_xattr_list);
-	if (size < sizeof(afs_xattr_list))
-		return -ERANGE;
-	memcpy(buffer, afs_xattr_list, sizeof(afs_xattr_list));
-	return sizeof(afs_xattr_list);
-}
-
 /*
  * Deal with the result of a successful fetch ACL operation.
  */
@@ -231,6 +208,8 @@ static int afs_xattr_get_yfs(const struct xattr_handler *handler,
 			else
 				ret = -ERANGE;
 		}
+	} else if (ret == -ENOTSUPP) {
+		ret = -ENODATA;
 	}
 
 error_yacl:
@@ -256,6 +235,7 @@ static int afs_xattr_set_yfs(const struct xattr_handler *handler,
 {
 	struct afs_operation *op;
 	struct afs_vnode *vnode = AFS_FS_I(inode);
+	int ret;
 
 	if (flags == XATTR_CREATE ||
 	    strcmp(name, "acl") != 0)
@@ -270,7 +250,10 @@ static int afs_xattr_set_yfs(const struct xattr_handler *handler,
 		return afs_put_operation(op);
 
 	op->ops = &yfs_store_opaque_acl2_operation;
-	return afs_do_sync_operation(op);
+	ret = afs_do_sync_operation(op);
+	if (ret == -ENOTSUPP)
+		ret = -ENODATA;
+	return ret;
 }
 
 static const struct xattr_handler afs_xattr_yfs_handler = {