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, 63 insertions, 0 deletions

diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
new file mode 100644
index 000000000..f37971197
--- /dev/null
+++ b/drivers/usb/dwc3/Makefile
@@ -0,0 +1,63 @@
+# SPDX-License-Identifier: GPL-2.0
+# define_trace.h needs to know how to find our header
+CFLAGS_trace.o				:= -I$(src)
+
+obj-$(CONFIG_USB_DWC3)			+= dwc3.o
+
+dwc3-y					:= core.o
+
+ifneq ($(CONFIG_TRACING),)
+	dwc3-y				+= trace.o
+endif
+
+ifneq ($(filter y,$(CONFIG_USB_DWC3_HOST) $(CONFIG_USB_DWC3_DUAL_ROLE)),)
+	dwc3-y				+= host.o
+endif
+
+ifneq ($(filter y,$(CONFIG_USB_DWC3_GADGET) $(CONFIG_USB_DWC3_DUAL_ROLE)),)
+	dwc3-y				+= gadget.o ep0.o
+endif
+
+ifneq ($(CONFIG_USB_DWC3_DUAL_ROLE),)
+	dwc3-y				+= drd.o
+endif
+
+ifneq ($(CONFIG_USB_DWC3_ULPI),)
+	dwc3-y				+= ulpi.o
+endif
+
+ifneq ($(CONFIG_DEBUG_FS),)
+	dwc3-y				+= debugfs.o
+endif
+
+##
+# Platform-specific glue layers go here
+#
+# NOTICE: Make sure your glue layer doesn't depend on anything
+# which is arch-specific and that it compiles on all situations.
+#
+# We want to keep this requirement in order to be able to compile
+# the entire driver (with all its glue layers) on several architectures
+# and make sure it compiles fine. This will also help with allmodconfig
+# and allyesconfig builds.
+##
+
+obj-$(CONFIG_USB_DWC3_AM62)		+= dwc3-am62.o
+obj-$(CONFIG_USB_DWC3_APPLE)		+= dwc3-apple.o
+obj-$(CONFIG_USB_DWC3_OMAP)		+= dwc3-omap.o
+obj-$(CONFIG_USB_DWC3_EXYNOS)		+= dwc3-exynos.o
+obj-$(CONFIG_USB_DWC3_PCI)		+= dwc3-pci.o
+obj-$(CONFIG_USB_DWC3_HAPS)		+= dwc3-haps.o
+obj-$(CONFIG_USB_DWC3_KEYSTONE)		+= dwc3-keystone.o
+obj-$(CONFIG_USB_DWC3_MESON_G12A)	+= dwc3-meson-g12a.o
+obj-$(CONFIG_USB_DWC3_OF_SIMPLE)	+= dwc3-of-simple.o
+obj-$(CONFIG_USB_DWC3_ST)		+= dwc3-st.o
+obj-$(CONFIG_USB_DWC3_QCOM)		+= dwc3-qcom.o
+obj-$(CONFIG_USB_DWC3_QCOM)		+= dwc3-qcom-legacy.o
+obj-$(CONFIG_USB_DWC3_IMX8MP)		+= dwc3-imx8mp.o
+obj-$(CONFIG_USB_DWC3_IMX)		+= dwc3-imx.o
+obj-$(CONFIG_USB_DWC3_XILINX)		+= dwc3-xilinx.o
+obj-$(CONFIG_USB_DWC3_OCTEON)		+= dwc3-octeon.o
+obj-$(CONFIG_USB_DWC3_RTK)		+= dwc3-rtk.o
+obj-$(CONFIG_USB_DWC3_GENERIC_PLAT)	+= dwc3-generic-plat.o
+obj-$(CONFIG_USB_DWC3_GOOGLE)		+= dwc3-google.o