Change calling conventions for filldir_t

filldir_t instances (directory iterators callbacks) used to return 0 for
"OK, keep going" or -E... for "stop".  Note that it's *NOT* how the
error values are reported - the rules for those are callback-dependent
and ->iterate{,_shared}() instances only care about zero vs. non-zero
(look at emit_dir() and friends).

So let's just return bool ("should we keep going?") - it's less confusing
that way.  The choice between "true means keep going" and "true means
stop" is bikesheddable; we have two groups of callbacks -
	do something for everything in directory, until we run into problem
and
	find an entry in directory and do something to it.

The former tended to use 0/-E... conventions - -E<something> on failure.
The latter tended to use 0/1, 1 being "stop, we are done".
The callers treated anything non-zero as "stop", ignoring which
non-zero value did they get.

"true means stop" would be more natural for the second group; "true
means keep going" - for the first one.  I tried both variants and
the things like
	if allocation failed
		something = -ENOMEM;
		return true;
just looked unnatural and asking for trouble.

[folded suggestion from Matthew Wilcox <willy@infradead.org>]
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 13 insertions, 17 deletions

diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 9751cc92c111..6785a9cc9ee1 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -3779,7 +3779,7 @@ static int reserve_populate_dentry(struct ksmbd_dir_info *d_info,
 	return 0;
 }
 
-static int __query_dir(struct dir_context *ctx, const char *name, int namlen,
+static bool __query_dir(struct dir_context *ctx, const char *name, int namlen,
 		       loff_t offset, u64 ino, unsigned int d_type)
 {
 	struct ksmbd_readdir_data	*buf;
@@ -3793,22 +3793,20 @@ static int __query_dir(struct dir_context *ctx, const char *name, int namlen,
 
 	/* dot and dotdot entries are already reserved */
 	if (!strcmp(".", name) || !strcmp("..", name))
-		return 0;
+		return true;
 	if (ksmbd_share_veto_filename(priv->work->tcon->share_conf, name))
-		return 0;
+		return true;
 	if (!match_pattern(name, namlen, priv->search_pattern))
-		return 0;
+		return true;
 
 	d_info->name		= name;
 	d_info->name_len	= namlen;
 	rc = reserve_populate_dentry(d_info, priv->info_level);
 	if (rc)
-		return rc;
-	if (d_info->flags & SMB2_RETURN_SINGLE_ENTRY) {
+		return false;
+	if (d_info->flags & SMB2_RETURN_SINGLE_ENTRY)
 		d_info->out_buf_len = 0;
-		return 0;
-	}
-	return 0;
+	return true;
 }
 
 static void restart_ctx(struct dir_context *ctx)
diff --git a/fs/ksmbd/vfs.c b/fs/ksmbd/vfs.c
index 78d01033604c..48b2b901f6e5 100644
--- a/fs/ksmbd/vfs.c
+++ b/fs/ksmbd/vfs.c
@@ -1105,7 +1105,7 @@ int ksmbd_vfs_unlink(struct user_namespace *user_ns,
 	return err;
 }
 
-static int __dir_empty(struct dir_context *ctx, const char *name, int namlen,
+static bool __dir_empty(struct dir_context *ctx, const char *name, int namlen,
 		       loff_t offset, u64 ino, unsigned int d_type)
 {
 	struct ksmbd_readdir_data *buf;
@@ -1113,9 +1113,7 @@ static int __dir_empty(struct dir_context *ctx, const char *name, int namlen,
 	buf = container_of(ctx, struct ksmbd_readdir_data, ctx);
 	buf->dirent_count++;
 
-	if (buf->dirent_count > 2)
-		return -ENOTEMPTY;
-	return 0;
+	return buf->dirent_count <= 2;
 }
 
 /**
@@ -1142,7 +1140,7 @@ int ksmbd_vfs_empty_dir(struct ksmbd_file *fp)
 	return err;
 }
 
-static int __caseless_lookup(struct dir_context *ctx, const char *name,
+static bool __caseless_lookup(struct dir_context *ctx, const char *name,
 			     int namlen, loff_t offset, u64 ino,
 			     unsigned int d_type)
 {
@@ -1151,13 +1149,13 @@ static int __caseless_lookup(struct dir_context *ctx, const char *name,
 	buf = container_of(ctx, struct ksmbd_readdir_data, ctx);
 
 	if (buf->used != namlen)
-		return 0;
+		return true;
 	if (!strncasecmp((char *)buf->private, name, namlen)) {
 		memcpy((char *)buf->private, name, namlen);
 		buf->dirent_count = 1;
-		return -EEXIST;
+		return false;
 	}
-	return 0;
+	return true;
 }
 
 /**