ata: libata-scsi: fix ata_dsm_trim_pages() kernel-docgrafted

make htmldocs fails with:

  Documentation/driver-api/libata:604: ./drivers/ata/libata-scsi.c:2301:
  ERROR: Unexpected indentation. [docutils]

The Return: section of ata_dsm_trim_pages() ends its first sentence with
a colon and continues with an indented bullet list. reStructuredText
requires a blank line before an indented block, so docutils chokes on
the list.

Simply adding the missing blank line does not work either: Return: is a
kernel-doc "special section", which is terminated by the first blank
line, so the bullet list would end up in the Description section,
detached from the sentence introducing it.

Spell the two bounds out as prose instead, so that the Return: section
stays self-contained. Documentation-only change.

Fixes: e64e6b5dc867 ("ata: libata-scsi: scale DSM TRIM payload by MAX PAGES PER DSM COMMAND")
Reported-by: Thomas Huth <thuth@redhat.com>
Closes: https://lore.kernel.org/linux-ide/b0a0b8e8-cc4f-4c7b-8bc5-fee0712d405a@redhat.com/
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Link: https://lore.kernel.org/r/20260916130031.29990-2-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>

1 files changed, 212 insertions, 0 deletions

diff --git a/lib/kunit/string-stream.c b/lib/kunit/string-stream.c
new file mode 100644
index 000000000..51ba40ebf
--- /dev/null
+++ b/lib/kunit/string-stream.c
@@ -0,0 +1,212 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * C++ stream style string builder used in KUnit for building messages.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#include <kunit/static_stub.h>
+#include <kunit/test.h>
+#include <linux/list.h>
+#include <linux/seq_buf.h>
+#include <linux/slab.h>
+
+#include "string-stream.h"
+
+
+static struct string_stream_fragment *alloc_string_stream_fragment(int len, gfp_t gfp)
+{
+	struct string_stream_fragment *frag;
+
+	frag = kzalloc_obj(*frag, gfp);
+	if (!frag)
+		return ERR_PTR(-ENOMEM);
+
+	frag->fragment = kmalloc(len, gfp);
+	if (!frag->fragment) {
+		kfree(frag);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	return frag;
+}
+
+static void string_stream_fragment_destroy(struct string_stream_fragment *frag)
+{
+	list_del(&frag->node);
+	kfree(frag->fragment);
+	kfree(frag);
+}
+
+int string_stream_vadd(struct string_stream *stream,
+		       const char *fmt,
+		       va_list args)
+{
+	struct string_stream_fragment *frag_container;
+	int buf_len, result_len;
+	va_list args_for_counting;
+
+	/* Make a copy because `vsnprintf` could change it */
+	va_copy(args_for_counting, args);
+
+	/* Evaluate length of formatted string */
+	buf_len = vsnprintf(NULL, 0, fmt, args_for_counting);
+
+	va_end(args_for_counting);
+
+	if (buf_len == 0)
+		return 0;
+
+	/* Reserve one extra for possible appended newline. */
+	if (stream->append_newlines)
+		buf_len++;
+
+	/* Need space for null byte. */
+	buf_len++;
+
+	frag_container = alloc_string_stream_fragment(buf_len, stream->gfp);
+	if (IS_ERR(frag_container))
+		return PTR_ERR(frag_container);
+
+	if (stream->append_newlines) {
+		/* Don't include reserved newline byte in writeable length. */
+		result_len = vsnprintf(frag_container->fragment, buf_len - 1, fmt, args);
+
+		/* Append newline if necessary. */
+		if (frag_container->fragment[result_len - 1] != '\n')
+			result_len += strscpy(frag_container->fragment + result_len,
+					      "\n", buf_len - result_len);
+	} else {
+		result_len = vsnprintf(frag_container->fragment, buf_len, fmt, args);
+	}
+
+	spin_lock(&stream->lock);
+	stream->length += result_len;
+	list_add_tail(&frag_container->node, &stream->fragments);
+	spin_unlock(&stream->lock);
+
+	return 0;
+}
+
+int string_stream_add(struct string_stream *stream, const char *fmt, ...)
+{
+	va_list args;
+	int result;
+
+	va_start(args, fmt);
+	result = string_stream_vadd(stream, fmt, args);
+	va_end(args);
+
+	return result;
+}
+
+void string_stream_clear(struct string_stream *stream)
+{
+	struct string_stream_fragment *frag_container, *frag_container_safe;
+
+	spin_lock(&stream->lock);
+	list_for_each_entry_safe(frag_container,
+				 frag_container_safe,
+				 &stream->fragments,
+				 node) {
+		string_stream_fragment_destroy(frag_container);
+	}
+	stream->length = 0;
+	spin_unlock(&stream->lock);
+}
+
+char *string_stream_get_string(struct string_stream *stream)
+{
+	struct string_stream_fragment *frag_container;
+	size_t buf_len = stream->length + 1; /* +1 for null byte. */
+	struct seq_buf sb;
+	char *buf;
+
+	buf = kzalloc(buf_len, stream->gfp);
+	if (!buf)
+		return NULL;
+
+	seq_buf_init(&sb, buf, buf_len);
+
+	spin_lock(&stream->lock);
+	list_for_each_entry(frag_container, &stream->fragments, node)
+		seq_buf_puts(&sb, frag_container->fragment);
+	spin_unlock(&stream->lock);
+
+	return buf;
+}
+
+int string_stream_append(struct string_stream *stream,
+			 struct string_stream *other)
+{
+	const char *other_content;
+	int ret;
+
+	other_content = string_stream_get_string(other);
+
+	if (!other_content)
+		return -ENOMEM;
+
+	ret = string_stream_add(stream, other_content);
+	kfree(other_content);
+
+	return ret;
+}
+
+bool string_stream_is_empty(struct string_stream *stream)
+{
+	return list_empty(&stream->fragments);
+}
+
+struct string_stream *alloc_string_stream(gfp_t gfp)
+{
+	struct string_stream *stream;
+
+	stream = kzalloc_obj(*stream, gfp);
+	if (!stream)
+		return ERR_PTR(-ENOMEM);
+
+	stream->gfp = gfp;
+	INIT_LIST_HEAD(&stream->fragments);
+	spin_lock_init(&stream->lock);
+
+	return stream;
+}
+
+void string_stream_destroy(struct string_stream *stream)
+{
+	KUNIT_STATIC_STUB_REDIRECT(string_stream_destroy, stream);
+
+	if (IS_ERR_OR_NULL(stream))
+		return;
+
+	string_stream_clear(stream);
+	kfree(stream);
+}
+
+static void resource_free_string_stream(void *p)
+{
+	struct string_stream *stream = p;
+
+	string_stream_destroy(stream);
+}
+
+struct string_stream *kunit_alloc_string_stream(struct kunit *test, gfp_t gfp)
+{
+	struct string_stream *stream;
+
+	stream = alloc_string_stream(gfp);
+	if (IS_ERR(stream))
+		return stream;
+
+	if (kunit_add_action_or_reset(test, resource_free_string_stream, stream) != 0)
+		return ERR_PTR(-ENOMEM);
+
+	return stream;
+}
+
+void kunit_free_string_stream(struct kunit *test, struct string_stream *stream)
+{
+	kunit_release_action(test, resource_free_string_stream, (void *)stream);
+}