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, 568 insertions, 0 deletions

diff --git a/drivers/hid/hid-haptic.c b/drivers/hid/hid-haptic.c
new file mode 100644
index 000000000..8760eeb08
--- /dev/null
+++ b/drivers/hid/hid-haptic.c
@@ -0,0 +1,568 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  HID Haptic support for Linux
+ *
+ *  Copyright (c) 2021 Angela Czubak <acz@semihalf.com>
+ */
+
+#include <linux/input/mt.h>
+#include <linux/module.h>
+
+#include "hid-haptic.h"
+
+void hid_haptic_feature_mapping(struct hid_device *hdev,
+				struct hid_haptic_device *haptic,
+				struct hid_field *field, struct hid_usage *usage)
+{
+	u16 usage_hid;
+
+	if (usage->hid == HID_HP_AUTOTRIGGER) {
+		if (usage->usage_index >= field->report_count) {
+			dev_err(&hdev->dev,
+				"HID_HP_AUTOTRIGGER out of range\n");
+			return;
+		}
+
+		hid_device_io_start(hdev);
+		hid_hw_request(hdev, field->report, HID_REQ_GET_REPORT);
+		hid_hw_wait(hdev);
+		hid_device_io_stop(hdev);
+		haptic->default_auto_trigger =
+			field->value[usage->usage_index];
+		haptic->auto_trigger_report = field->report;
+	} else if ((usage->hid & HID_USAGE_PAGE) == HID_UP_ORDINAL) {
+		usage_hid = usage->hid & HID_USAGE;
+		switch (field->logical) {
+		case HID_HP_WAVEFORMLIST:
+			if (usage_hid > haptic->max_waveform_id)
+				haptic->max_waveform_id = usage_hid;
+			break;
+		case HID_HP_DURATIONLIST:
+			if (usage_hid > haptic->max_duration_id)
+				haptic->max_duration_id = usage_hid;
+			break;
+		default:
+			break;
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(hid_haptic_feature_mapping);
+
+bool hid_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
+				    struct hid_input *hi, struct hid_field *field)
+{
+	if (field->unit == HID_UNIT_GRAM || field->unit == HID_UNIT_NEWTON) {
+		haptic->force_logical_minimum = field->logical_minimum;
+		haptic->force_physical_minimum = field->physical_minimum;
+		haptic->force_resolution = input_abs_get_res(hi->input,
+							     ABS_MT_PRESSURE);
+		return true;
+	}
+	return false;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_check_pressure_unit);
+
+int hid_haptic_input_mapping(struct hid_device *hdev,
+			     struct hid_haptic_device *haptic,
+			     struct hid_input *hi,
+			     struct hid_field *field, struct hid_usage *usage,
+			     unsigned long **bit, int *max)
+{
+	if (usage->hid == HID_HP_MANUALTRIGGER) {
+		haptic->manual_trigger_report = field->report;
+		/* we don't really want to map these fields */
+		return -1;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_input_mapping);
+
+int hid_haptic_input_configured(struct hid_device *hdev,
+				struct hid_haptic_device *haptic,
+				struct hid_input *hi)
+{
+	int error;
+
+	if (hi->application != HID_DG_TOUCHPAD)
+		return -1;
+
+	if (!haptic->auto_trigger_report || !haptic->manual_trigger_report)
+		return 0;
+
+	__set_bit(INPUT_PROP_PRESSUREPAD, hi->input->propbit);
+
+	error = hid_haptic_init(hdev, haptic, hi->input);
+	if (error) {
+		dev_warn(&hdev->dev, "Cannot allocate haptic for %s\n",
+			 hdev->name);
+		return 0;
+	}
+
+	return 1;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_input_configured);
+
+static void parse_auto_trigger_field(struct hid_haptic_device *haptic,
+				     struct hid_field *field)
+{
+	int count = field->report_count;
+	int n;
+	u16 usage_hid;
+
+	for (n = 0; n < count; n++) {
+		switch (field->usage[n].hid & HID_USAGE_PAGE) {
+		case HID_UP_ORDINAL:
+			usage_hid = field->usage[n].hid & HID_USAGE;
+			switch (field->logical) {
+			case HID_HP_WAVEFORMLIST:
+				haptic->hid_usage_map[usage_hid] = field->value[n];
+				if (field->value[n] ==
+				    (HID_HP_WAVEFORMPRESS & HID_USAGE)) {
+					haptic->press_ordinal = usage_hid;
+				} else if (field->value[n] ==
+					   (HID_HP_WAVEFORMRELEASE & HID_USAGE)) {
+					haptic->release_ordinal = usage_hid;
+				}
+				break;
+			case HID_HP_DURATIONLIST:
+				haptic->duration_map[usage_hid] =
+					field->value[n];
+				break;
+			default:
+				break;
+			}
+			break;
+		case HID_UP_HAPTIC:
+			switch (field->usage[n].hid) {
+			case HID_HP_WAVEFORMVENDORID:
+				haptic->vendor_id = field->value[n];
+				break;
+			case HID_HP_WAVEFORMVENDORPAGE:
+				haptic->vendor_page = field->value[n];
+				break;
+			default:
+				break;
+			}
+			break;
+		default:
+			/* Should not really happen */
+			break;
+		}
+	}
+}
+
+static void fill_effect_buf(struct hid_haptic_device *haptic,
+			    struct ff_haptic_effect *effect,
+			    struct hid_haptic_effect *haptic_effect,
+			    int waveform_ordinal)
+{
+	struct hid_report *rep = haptic->manual_trigger_report;
+	struct hid_usage *usage;
+	struct hid_field *field;
+	s32 value;
+	int i, j;
+	u8 *buf = haptic_effect->report_buf;
+
+	mutex_lock(&haptic->manual_trigger_mutex);
+	for (i = 0; i < rep->maxfield; i++) {
+		field = rep->field[i];
+		/* Ignore if report count is out of bounds. */
+		if (field->report_count < 1)
+			continue;
+
+		for (j = 0; j < field->maxusage; j++) {
+			usage = &field->usage[j];
+
+			switch (usage->hid) {
+			case HID_HP_INTENSITY:
+				if (effect->intensity > 100) {
+					value = field->logical_maximum;
+				} else {
+					value = field->logical_minimum +
+						effect->intensity *
+						(field->logical_maximum -
+						 field->logical_minimum) / 100;
+				}
+				break;
+			case HID_HP_REPEATCOUNT:
+				value = effect->repeat_count;
+				break;
+			case HID_HP_RETRIGGERPERIOD:
+				value = effect->retrigger_period;
+				break;
+			case HID_HP_MANUALTRIGGER:
+				value = waveform_ordinal;
+				break;
+			default:
+				continue;
+			}
+
+			field->value[j] = value;
+		}
+	}
+
+	hid_output_report(rep, buf);
+	mutex_unlock(&haptic->manual_trigger_mutex);
+}
+
+static void switch_mode(struct hid_device *hdev, struct hid_haptic_device *haptic,
+			int mode)
+{
+	struct hid_report *rep = haptic->auto_trigger_report;
+	struct hid_field *field;
+	s32 value;
+	int i, j;
+
+	if (mode == HID_HAPTIC_MODE_HOST)
+		value = HID_HAPTIC_ORDINAL_WAVEFORMSTOP;
+	else
+		value = haptic->default_auto_trigger;
+
+	mutex_lock(&haptic->auto_trigger_mutex);
+	for (i = 0; i < rep->maxfield; i++) {
+		field = rep->field[i];
+		/* Ignore if report count is out of bounds. */
+		if (field->report_count < 1)
+			continue;
+
+		for (j = 0; j < field->maxusage; j++) {
+			if (field->usage[j].hid == HID_HP_AUTOTRIGGER)
+				field->value[j] = value;
+		}
+	}
+
+	/* send the report */
+	hid_hw_request(hdev, rep, HID_REQ_SET_REPORT);
+	mutex_unlock(&haptic->auto_trigger_mutex);
+	haptic->mode = mode;
+}
+
+static int hid_haptic_upload_effect(struct input_dev *dev, struct ff_effect *effect,
+				    struct ff_effect *old)
+{
+	struct hid_device *hdev = input_get_drvdata(dev);
+	struct ff_device *ff = dev->ff;
+	struct hid_haptic_device *haptic = ff->private;
+	int i, ordinal = 0;
+	bool switch_modes = false;
+
+	/* If vendor range, check vendor id and page */
+	if (effect->u.haptic.hid_usage >= (HID_HP_VENDORWAVEFORMMIN & HID_USAGE) &&
+	    effect->u.haptic.hid_usage <= (HID_HP_VENDORWAVEFORMMAX & HID_USAGE) &&
+	    (effect->u.haptic.vendor_id != haptic->vendor_id ||
+	     effect->u.haptic.vendor_waveform_page != haptic->vendor_page))
+		return -EINVAL;
+
+	/* Check hid_usage */
+	for (i = 1; i <= haptic->max_waveform_id; i++) {
+		if (haptic->hid_usage_map[i] == effect->u.haptic.hid_usage) {
+			ordinal = i;
+			break;
+		}
+	}
+	if (ordinal < 1)
+		return -EINVAL;
+
+	/* Fill the buffer for the effect id */
+	fill_effect_buf(haptic, &effect->u.haptic, &haptic->effect[effect->id],
+			ordinal);
+
+	if (effect->u.haptic.hid_usage == (HID_HP_WAVEFORMPRESS & HID_USAGE) ||
+			effect->u.haptic.hid_usage == (HID_HP_WAVEFORMRELEASE & HID_USAGE))
+		switch_modes = true;
+
+	/* If device is in autonomous mode, and the uploaded effect signals userspace
+	 * wants control of the device, change modes
+	 */
+	if (switch_modes && haptic->mode == HID_HAPTIC_MODE_DEVICE)
+		switch_mode(hdev, haptic, HID_HAPTIC_MODE_HOST);
+
+	return 0;
+}
+
+static int play_effect(struct hid_device *hdev, struct hid_haptic_device *haptic,
+		       struct hid_haptic_effect *effect)
+{
+	int ret;
+
+	ret = hid_hw_output_report(hdev, effect->report_buf,
+				   haptic->manual_trigger_report_len);
+	if (ret < 0) {
+		ret = hid_hw_raw_request(hdev,
+					 haptic->manual_trigger_report->id,
+					 effect->report_buf,
+					 haptic->manual_trigger_report_len,
+					 HID_OUTPUT_REPORT, HID_REQ_SET_REPORT);
+	}
+
+	return ret;
+}
+
+static void haptic_work_handler(struct work_struct *work)
+{
+
+	struct hid_haptic_effect *effect = container_of(work,
+							struct hid_haptic_effect,
+							work);
+	struct input_dev *dev = effect->input_dev;
+	struct hid_device *hdev = input_get_drvdata(dev);
+	struct hid_haptic_device *haptic = dev->ff->private;
+
+	mutex_lock(&haptic->manual_trigger_mutex);
+	if (effect != &haptic->stop_effect)
+		play_effect(hdev, haptic, &haptic->stop_effect);
+
+	play_effect(hdev, haptic, effect);
+	mutex_unlock(&haptic->manual_trigger_mutex);
+
+}
+
+static int hid_haptic_playback(struct input_dev *dev, int effect_id, int value)
+{
+	struct hid_haptic_device *haptic = dev->ff->private;
+
+	if (value)
+		queue_work(haptic->wq, &haptic->effect[effect_id].work);
+	else
+		queue_work(haptic->wq, &haptic->stop_effect.work);
+
+	return 0;
+}
+
+static void effect_set_default(struct ff_effect *effect)
+{
+	effect->type = FF_HAPTIC;
+	effect->id = -1;
+	effect->u.haptic.hid_usage = HID_HP_WAVEFORMNONE & HID_USAGE;
+	effect->u.haptic.intensity = 100;
+	effect->u.haptic.retrigger_period = 0;
+	effect->u.haptic.repeat_count = 0;
+}
+
+static int hid_haptic_erase(struct input_dev *dev, int effect_id)
+{
+	struct hid_haptic_device *haptic = dev->ff->private;
+	struct hid_device *hdev = input_get_drvdata(dev);
+	struct ff_effect effect;
+	int ordinal;
+
+	effect_set_default(&effect);
+
+	if (effect.u.haptic.hid_usage == (HID_HP_WAVEFORMRELEASE & HID_USAGE)) {
+		ordinal = haptic->release_ordinal;
+		if (!ordinal) {
+			ordinal = HID_HAPTIC_ORDINAL_WAVEFORMNONE;
+			if (haptic->mode == HID_HAPTIC_MODE_HOST)
+				switch_mode(hdev, haptic, HID_HAPTIC_MODE_DEVICE);
+		} else
+			effect.u.haptic.hid_usage = HID_HP_WAVEFORMRELEASE & HID_USAGE;
+
+		fill_effect_buf(haptic, &effect.u.haptic, &haptic->effect[effect_id],
+				ordinal);
+	} else if (effect.u.haptic.hid_usage == (HID_HP_WAVEFORMPRESS & HID_USAGE)) {
+		ordinal = haptic->press_ordinal;
+		if (!ordinal) {
+			ordinal = HID_HAPTIC_ORDINAL_WAVEFORMNONE;
+			if (haptic->mode == HID_HAPTIC_MODE_HOST)
+				switch_mode(hdev, haptic, HID_HAPTIC_MODE_DEVICE);
+		}
+		else
+			effect.u.haptic.hid_usage = HID_HP_WAVEFORMPRESS & HID_USAGE;
+
+		fill_effect_buf(haptic, &effect.u.haptic, &haptic->effect[effect_id],
+				ordinal);
+	}
+
+	return 0;
+}
+
+static void hid_haptic_destroy(struct ff_device *ff)
+{
+	struct hid_haptic_device *haptic = ff->private;
+	struct hid_device *hdev = haptic->hdev;
+	int r;
+
+	if (hdev)
+		put_device(&hdev->dev);
+
+	kfree(haptic->stop_effect.report_buf);
+	haptic->stop_effect.report_buf = NULL;
+
+	if (haptic->effect) {
+		for (r = 0; r < ff->max_effects; r++)
+			kfree(haptic->effect[r].report_buf);
+		kfree(haptic->effect);
+	}
+	haptic->effect = NULL;
+
+	destroy_workqueue(haptic->wq);
+	haptic->wq = NULL;
+
+	kfree(haptic->duration_map);
+	haptic->duration_map = NULL;
+
+	kfree(haptic->hid_usage_map);
+	haptic->hid_usage_map = NULL;
+
+	module_put(THIS_MODULE);
+}
+
+int hid_haptic_init(struct hid_device *hdev,
+		    struct hid_haptic_device *haptic,
+		    struct input_dev *dev)
+{
+	struct ff_device *ff;
+	int ret = 0, r;
+	struct ff_haptic_effect stop_effect = {
+		.hid_usage = HID_HP_WAVEFORMSTOP & HID_USAGE,
+	};
+	const char *prefix = "hid-haptic";
+	char *name;
+	int (*flush)(struct input_dev *dev, struct file *file);
+	int (*event)(struct input_dev *dev, unsigned int type, unsigned int code, int value);
+
+	haptic->hdev = hdev;
+	haptic->max_waveform_id = max(2u, haptic->max_waveform_id);
+	haptic->max_duration_id = max(2u, haptic->max_duration_id);
+
+	haptic->hid_usage_map = kcalloc(haptic->max_waveform_id + 1,
+					sizeof(u16), GFP_KERNEL);
+	if (!haptic->hid_usage_map) {
+		ret = -ENOMEM;
+		goto exit;
+	}
+	haptic->duration_map = kcalloc(haptic->max_duration_id + 1,
+				       sizeof(u32), GFP_KERNEL);
+	if (!haptic->duration_map) {
+		ret = -ENOMEM;
+		goto usage_map;
+	}
+
+	if (haptic->max_waveform_id != haptic->max_duration_id)
+		dev_warn(&hdev->dev,
+			 "Haptic duration and waveform lists have different max id (%u and %u).\n",
+			 haptic->max_duration_id, haptic->max_waveform_id);
+
+	haptic->hid_usage_map[HID_HAPTIC_ORDINAL_WAVEFORMNONE] =
+		HID_HP_WAVEFORMNONE & HID_USAGE;
+	haptic->hid_usage_map[HID_HAPTIC_ORDINAL_WAVEFORMSTOP] =
+		HID_HP_WAVEFORMSTOP & HID_USAGE;
+
+	mutex_init(&haptic->auto_trigger_mutex);
+	for (r = 0; r < haptic->auto_trigger_report->maxfield; r++)
+		parse_auto_trigger_field(haptic, haptic->auto_trigger_report->field[r]);
+
+	haptic->input_dev = dev;
+	haptic->manual_trigger_report_len =
+		hid_report_len(haptic->manual_trigger_report);
+	mutex_init(&haptic->manual_trigger_mutex);
+	name = kmalloc(strlen(prefix) + strlen(hdev->name) + 2, GFP_KERNEL);
+	if (name) {
+		sprintf(name, "%s %s", prefix, hdev->name);
+		haptic->wq = create_singlethread_workqueue(name);
+		kfree(name);
+	}
+	if (!haptic->wq) {
+		ret = -ENOMEM;
+		goto duration_map;
+	}
+	haptic->effect = kzalloc_objs(struct hid_haptic_effect, FF_MAX_EFFECTS);
+	if (!haptic->effect) {
+		ret = -ENOMEM;
+		goto output_queue;
+	}
+	for (r = 0; r < FF_MAX_EFFECTS; r++) {
+		haptic->effect[r].report_buf =
+			hid_alloc_report_buf(haptic->manual_trigger_report,
+					     GFP_KERNEL);
+		if (!haptic->effect[r].report_buf) {
+			dev_err(&hdev->dev,
+				"Failed to allocate a buffer for an effect.\n");
+			ret = -ENOMEM;
+			goto buffer_free;
+		}
+		haptic->effect[r].input_dev = dev;
+		INIT_WORK(&haptic->effect[r].work, haptic_work_handler);
+	}
+	haptic->stop_effect.report_buf =
+		hid_alloc_report_buf(haptic->manual_trigger_report,
+				     GFP_KERNEL);
+	if (!haptic->stop_effect.report_buf) {
+		dev_err(&hdev->dev,
+			"Failed to allocate a buffer for stop effect.\n");
+		ret = -ENOMEM;
+		goto buffer_free;
+	}
+	haptic->stop_effect.input_dev = dev;
+	INIT_WORK(&haptic->stop_effect.work, haptic_work_handler);
+	fill_effect_buf(haptic, &stop_effect, &haptic->stop_effect,
+			HID_HAPTIC_ORDINAL_WAVEFORMSTOP);
+
+	input_set_capability(dev, EV_FF, FF_HAPTIC);
+
+	flush = dev->flush;
+	event = dev->event;
+	ret = input_ff_create(dev, FF_MAX_EFFECTS);
+	if (ret) {
+		dev_err(&hdev->dev, "Failed to create ff device.\n");
+		goto stop_buffer_free;
+	}
+
+	ff = dev->ff;
+	ff->private = haptic;
+	ff->upload = hid_haptic_upload_effect;
+	ff->playback = hid_haptic_playback;
+	ff->erase = hid_haptic_erase;
+	ff->destroy = hid_haptic_destroy;
+	if (!try_module_get(THIS_MODULE)) {
+		dev_err(&hdev->dev, "Failed to increase module count.\n");
+		goto input_free;
+	}
+	if (!get_device(&hdev->dev)) {
+		dev_err(&hdev->dev, "Failed to get hdev device.\n");
+		module_put(THIS_MODULE);
+		goto input_free;
+	}
+	return 0;
+
+input_free:
+	input_ff_destroy(dev);
+	/* Restore dev flush and event */
+	dev->flush = flush;
+	dev->event = event;
+	return ret;
+stop_buffer_free:
+	kfree(haptic->stop_effect.report_buf);
+	haptic->stop_effect.report_buf = NULL;
+buffer_free:
+	while (--r >= 0)
+		kfree(haptic->effect[r].report_buf);
+	kfree(haptic->effect);
+	haptic->effect = NULL;
+output_queue:
+	destroy_workqueue(haptic->wq);
+	haptic->wq = NULL;
+duration_map:
+	kfree(haptic->duration_map);
+	haptic->duration_map = NULL;
+usage_map:
+	kfree(haptic->hid_usage_map);
+	haptic->hid_usage_map = NULL;
+exit:
+	return ret;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_init);
+
+void hid_haptic_pressure_reset(struct hid_haptic_device *haptic)
+{
+	haptic->pressure_sum = 0;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_pressure_reset);
+
+void hid_haptic_pressure_increase(struct hid_haptic_device *haptic,
+				 __s32 pressure)
+{
+	haptic->pressure_sum += pressure;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_pressure_increase);