Merge tag 'vfs/v6.4-rc3/misc.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs fixes from Christian Brauner:

 - During the acl rework we merged this cycle the generic_listxattr()
   helper had to be modified in a way that in principle it would allow
   for POSIX ACLs to be reported. At least that was the impression we
   had initially. Because before the acl rework POSIX ACLs would be
   reported if the filesystem did have POSIX ACL xattr handlers in
   sb->s_xattr. That logic changed and now we can simply check whether
   the superblock has SB_POSIXACL set and if the inode has
   inode->i_{default_}acl set report the appropriate POSIX ACL name.

   However, we didn't realize that generic_listxattr() was only ever
   used by two filesystems. Both of them don't support POSIX ACLs via
   sb->s_xattr handlers and so never reported POSIX ACLs via
   generic_listxattr() even if they raised SB_POSIXACL and did contain
   inodes which had acls set. The example here is nfs4.

   As a result, generic_listxattr() suddenly started reporting POSIX
   ACLs when it wouldn't have before. Since SB_POSIXACL implies that the
   umask isn't stripped in the VFS nfs4 can't just drop SB_POSIXACL from
   the superblock as it would also alter umask handling for them.

   So just have generic_listxattr() not report POSIX ACLs as it never
   did anyway. It's documented as such.

 - Our SB_* flags currently use a signed integer and we shift the last
   bit causing UBSAN to complain about undefined behavior. Switch to
   using unsigned. While the original patch used an explicit unsigned
   bitshift it's now pretty common to rely on the BIT() macro in a lot
   of headers nowadays. So the patch has been adjusted to use that.

 - Add Namjae as ntfs reviewer. They're already active this cycle so
   let's make it explicit right now.

* tag 'vfs/v6.4-rc3/misc.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  ntfs: Add myself as a reviewer
  fs: don't call posix_acl_listxattr in generic_listxattr
  fs: fix undefined behavior in bit shift for SB_NOUSER

1 files changed, 9 insertions, 6 deletions

diff --git a/fs/xattr.c b/fs/xattr.c
index fcf67d80d7f9..e7bbb7f57557 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -985,9 +985,16 @@ int xattr_list_one(char **buffer, ssize_t *remaining_size, const char *name)
 	return 0;
 }
 
-/*
+/**
+ * generic_listxattr - run through a dentry's xattr list() operations
+ * @dentry: dentry to list the xattrs
+ * @buffer: result buffer
+ * @buffer_size: size of @buffer
+ *
  * Combine the results of the list() operation from every xattr_handler in the
- * list.
+ * xattr_handler stack.
+ *
+ * Note that this will not include the entries for POSIX ACLs.
  */
 ssize_t
 generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
@@ -996,10 +1003,6 @@ generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
 	ssize_t remaining_size = buffer_size;
 	int err = 0;
 
-	err = posix_acl_listxattr(d_inode(dentry), &buffer, &remaining_size);
-	if (err)
-		return err;
-
 	for_each_xattr_handler(handlers, handler) {
 		if (!handler->name || (handler->list && !handler->list(dentry)))
 			continue;