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, 37 insertions, 0 deletions

diff --git a/drivers/usb/misc/Makefile b/drivers/usb/misc/Makefile
new file mode 100644
index 000000000..494ab0377
--- /dev/null
+++ b/drivers/usb/misc/Makefile
@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the rest of the USB drivers
+# (the ones that don't fit into any other categories)
+#
+obj-$(CONFIG_USB_ADUTUX)		+= adutux.o
+obj-$(CONFIG_USB_APPLEDISPLAY)		+= appledisplay.o
+obj-$(CONFIG_USB_CYPRESS_CY7C63)	+= cypress_cy7c63.o
+obj-$(CONFIG_USB_CYTHERM)		+= cytherm.o
+obj-$(CONFIG_USB_EMI26)			+= emi26.o
+obj-$(CONFIG_USB_EMI62)			+= emi62.o
+obj-$(CONFIG_USB_EZUSB_FX2)		+= ezusb.o
+obj-$(CONFIG_APPLE_MFI_FASTCHARGE)	+= apple-mfi-fastcharge.o
+obj-$(CONFIG_USB_LJCA)			+= usb-ljca.o
+obj-$(CONFIG_USB_USBIO)			+= usbio.o
+obj-$(CONFIG_USB_IDMOUSE)		+= idmouse.o
+obj-$(CONFIG_USB_IOWARRIOR)		+= iowarrior.o
+obj-$(CONFIG_USB_ISIGHTFW)		+= isight_firmware.o
+obj-$(CONFIG_USB_LCD)			+= usblcd.o
+obj-$(CONFIG_USB_LD)			+= ldusb.o
+obj-$(CONFIG_USB_LEGOTOWER)		+= legousbtower.o
+obj-$(CONFIG_USB_QCOM_EUD)		+= qcom_eud.o
+obj-$(CONFIG_USB_TEST)			+= usbtest.o
+obj-$(CONFIG_USB_EHSET_TEST_FIXTURE)    += ehset.o
+obj-$(CONFIG_USB_TRANCEVIBRATOR)	+= trancevibrator.o
+obj-$(CONFIG_USB_USS720)		+= uss720.o
+obj-$(CONFIG_USB_SEVSEG)		+= usbsevseg.o
+obj-$(CONFIG_USB_YUREX)			+= yurex.o
+obj-$(CONFIG_USB_HUB_USB251XB)		+= usb251xb.o
+obj-$(CONFIG_USB_HSIC_USB3503)		+= usb3503.o
+obj-$(CONFIG_USB_HSIC_USB4604)		+= usb4604.o
+obj-$(CONFIG_USB_CHAOSKEY)		+= chaoskey.o
+
+obj-$(CONFIG_USB_SISUSBVGA)		+= sisusbvga/
+obj-$(CONFIG_USB_LINK_LAYER_TEST)	+= lvstest.o
+obj-$(CONFIG_BRCM_USB_PINMAP)		+= brcmstb-usb-pinmap.o
+obj-$(CONFIG_USB_ONBOARD_DEV)		+= onboard_usb_dev.o