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, 24 insertions, 0 deletions

diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
new file mode 100644
index 000000000..ceae46c53
--- /dev/null
+++ b/drivers/usb/phy/Makefile
@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for physical layer USB drivers
+#
+obj-$(CONFIG_USB_PHY)			+= phy.o
+obj-$(CONFIG_OF)			+= of.o
+
+# transceiver drivers, keep the list sorted
+
+obj-$(CONFIG_AB8500_USB)		+= phy-ab8500-usb.o
+obj-$(CONFIG_FSL_USB2_OTG)		+= phy-fsl-usb.o
+obj-$(CONFIG_NOP_USB_XCEIV)		+= phy-generic.o
+obj-$(CONFIG_TAHVO_USB)			+= phy-tahvo.o
+obj-$(CONFIG_AM335X_CONTROL_USB)	+= phy-am335x-control.o
+obj-$(CONFIG_AM335X_PHY_USB)		+= phy-am335x.o
+obj-$(CONFIG_OMAP_OTG)			+= phy-omap-otg.o
+obj-$(CONFIG_TWL6030_USB)		+= phy-twl6030-usb.o
+obj-$(CONFIG_USB_TEGRA_PHY)		+= phy-tegra-usb.o
+obj-$(CONFIG_USB_GPIO_VBUS)		+= phy-gpio-vbus-usb.o
+obj-$(CONFIG_USB_ISP1301)		+= phy-isp1301.o
+obj-$(CONFIG_USB_MXS_PHY)		+= phy-mxs-usb.o
+obj-$(CONFIG_USB_ULPI)			+= phy-ulpi.o
+obj-$(CONFIG_USB_ULPI_VIEWPORT)		+= phy-ulpi-viewport.o
+obj-$(CONFIG_KEYSTONE_USB_PHY)		+= phy-keystone.o