netfs: zero the tail of a short DIO/unbuffered readgrafted

The buffered read collector zero-fills the tail of a short read that
stops below the inode's i_size (netfs_clear_unread()), so a read that
races an extending write still returns the expected number of bytes.
The non-buffered collector path does no such thing: it just records
how much was transferred.

Add the same zero-fill for the non-buffered case, gated on
NETFS_SREQ_CLEAR_TAIL: a subreq's source sets that flag when a short
result from it is known to be safe to treat as a hole, as opposed to
NETFS_SREQ_HIT_EOF, which means the read genuinely ran off the end of
the file and should be reported short as-is. Only CLEAR_TAIL should
zero-fill here; a real EOF must stay a real short read.

No source currently sets CLEAR_TAIL on an unbuffered/DIO subrequest,
so this is inert on its own -- a following change teaches cifs to set
it in the one case that needs it.

Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item")
Reviewed-by: David Howells <dhowells@redhat.com>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Cc: Shyam Prasad N <sprasad@microsoft.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Bharath SM <bharathsm@microsoft.com>
Cc: stable@vger.kernel.org

1 files changed, 85 insertions, 0 deletions

diff --git a/drivers/hid/hid-input-test.c b/drivers/hid/hid-input-test.c
new file mode 100644
index 000000000..c92008daf
--- /dev/null
+++ b/drivers/hid/hid-input-test.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  HID to Linux Input mapping
+ *
+ *  Copyright (c) 2022 José Expósito <jose.exposito89@gmail.com>
+ */
+
+#include <kunit/test.h>
+
+static void hid_test_input_update_battery_charge_status(struct kunit *test)
+{
+	struct hid_battery *bat;
+	bool handled;
+
+	bat = kunit_kzalloc(test, sizeof(*bat), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bat);
+
+	handled = hidinput_update_battery_charge_status(bat, HID_DG_HEIGHT, 0);
+	KUNIT_EXPECT_FALSE(test, handled);
+	KUNIT_EXPECT_EQ(test, bat->charge_status, POWER_SUPPLY_STATUS_UNKNOWN);
+
+	handled = hidinput_update_battery_charge_status(bat, HID_BAT_CHARGING, 0);
+	KUNIT_EXPECT_TRUE(test, handled);
+	KUNIT_EXPECT_EQ(test, bat->charge_status, POWER_SUPPLY_STATUS_DISCHARGING);
+
+	handled = hidinput_update_battery_charge_status(bat, HID_BAT_CHARGING, 1);
+	KUNIT_EXPECT_TRUE(test, handled);
+	KUNIT_EXPECT_EQ(test, bat->charge_status, POWER_SUPPLY_STATUS_CHARGING);
+}
+
+static void hid_test_input_get_battery_property(struct kunit *test)
+{
+	struct power_supply *psy;
+	struct hid_battery *bat;
+	struct hid_device *dev;
+	union power_supply_propval val;
+	int ret;
+
+	dev = kunit_kzalloc(test, sizeof(*dev), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev);
+
+	bat = kunit_kzalloc(test, sizeof(*bat), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bat);
+	bat->dev = dev;
+	bat->avoid_query = true;
+
+	psy = kunit_kzalloc(test, sizeof(*psy), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, psy);
+	psy->drv_data = bat;
+
+	bat->status = HID_BATTERY_UNKNOWN;
+	bat->charge_status = POWER_SUPPLY_STATUS_CHARGING;
+	ret = hidinput_get_battery_property(psy, POWER_SUPPLY_PROP_STATUS, &val);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, val.intval, POWER_SUPPLY_STATUS_UNKNOWN);
+
+	bat->status = HID_BATTERY_REPORTED;
+	bat->charge_status = POWER_SUPPLY_STATUS_CHARGING;
+	ret = hidinput_get_battery_property(psy, POWER_SUPPLY_PROP_STATUS, &val);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, val.intval, POWER_SUPPLY_STATUS_CHARGING);
+
+	bat->status = HID_BATTERY_REPORTED;
+	bat->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
+	ret = hidinput_get_battery_property(psy, POWER_SUPPLY_PROP_STATUS, &val);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, val.intval, POWER_SUPPLY_STATUS_DISCHARGING);
+}
+
+static struct kunit_case hid_input_tests[] = {
+	KUNIT_CASE(hid_test_input_update_battery_charge_status),
+	KUNIT_CASE(hid_test_input_get_battery_property),
+	{ }
+};
+
+static struct kunit_suite hid_input_test_suite = {
+	.name = "hid_input",
+	.test_cases = hid_input_tests,
+};
+
+kunit_test_suite(hid_input_test_suite);
+
+MODULE_DESCRIPTION("HID input KUnit tests");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("José Expósito <jose.exposito89@gmail.com>");