From dd05add7b2b6004c5fa3a1f276f56d8668f86b65 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Sat, 26 Sep 2026 19:20:30 -0300 Subject: netfs: zero the tail of a short DIO/unbuffered read 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 Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: Christian Brauner Cc: Matthew Wilcox Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Bharath SM Cc: stable@vger.kernel.org --- drivers/hid/hid-generic.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 drivers/hid/hid-generic.c (limited to 'drivers/hid/hid-generic.c') diff --git a/drivers/hid/hid-generic.c b/drivers/hid/hid-generic.c new file mode 100644 index 000000000..c2de91674 --- /dev/null +++ b/drivers/hid/hid-generic.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * HID support for Linux + * + * Copyright (c) 1999 Andreas Gal + * Copyright (c) 2000-2005 Vojtech Pavlik + * Copyright (c) 2005 Michael Haboustak for Concept2, Inc + * Copyright (c) 2007-2008 Oliver Neukum + * Copyright (c) 2006-2012 Jiri Kosina + * Copyright (c) 2012 Henrik Rydberg + */ + +/* + */ + +#include +#include +#include +#include +#include + +#include + +static struct hid_driver hid_generic; + +static int __check_hid_generic(struct device_driver *drv, void *data) +{ + struct hid_driver *hdrv = to_hid_driver(drv); + struct hid_device *hdev = data; + + if (hdrv == &hid_generic) + return 0; + + return hid_match_device(hdev, hdrv) != NULL; +} + +static bool hid_generic_match(struct hid_device *hdev, + bool ignore_special_driver) +{ + if (ignore_special_driver) + return true; + + if (hdev->quirks & HID_QUIRK_IGNORE_SPECIAL_DRIVER) + return true; + + if (hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER) + return false; + + /* + * If any other driver wants the device, leave the device to this other + * driver. + */ + if (bus_for_each_drv(&hid_bus_type, NULL, hdev, __check_hid_generic)) + return false; + + return true; +} + +static int hid_generic_probe(struct hid_device *hdev, + const struct hid_device_id *id) +{ + int ret; + + hdev->quirks |= HID_QUIRK_INPUT_PER_APP; + + ret = hid_parse(hdev); + if (ret) + return ret; + + return hid_hw_start(hdev, HID_CONNECT_DEFAULT); +} + +static int hid_generic_reset_resume(struct hid_device *hdev) +{ + if (hdev->claimed & HID_CLAIMED_INPUT) + hidinput_reset_resume(hdev); + + return 0; +} + +static const struct hid_device_id hid_table[] = { + { HID_DEVICE(HID_BUS_ANY, HID_GROUP_ANY, HID_ANY_ID, HID_ANY_ID) }, + { } +}; +MODULE_DEVICE_TABLE(hid, hid_table); + +static struct hid_driver hid_generic = { + .name = "hid-generic", + .id_table = hid_table, + .match = hid_generic_match, + .probe = hid_generic_probe, + .reset_resume = hid_generic_reset_resume, +}; +module_hid_driver(hid_generic); + +MODULE_AUTHOR("Henrik Rydberg"); +MODULE_DESCRIPTION("HID generic driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1