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, 32 insertions, 0 deletions

diff --git a/drivers/input/Makefile b/drivers/input/Makefile
new file mode 100644
index 000000000..2cd6e1c9a
--- /dev/null
+++ b/drivers/input/Makefile
@@ -0,0 +1,32 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the input core drivers.
+#
+
+# Each configuration option enables a list of files.
+
+obj-$(CONFIG_INPUT)		+= input-core.o
+input-core-y := input.o input-compat.o input-mt.o input-poller.o ff-core.o
+input-core-y += touchscreen.o touch-overlay.o
+
+obj-$(CONFIG_INPUT_FF_MEMLESS)	+= ff-memless.o
+obj-$(CONFIG_INPUT_SPARSEKMAP)	+= sparse-keymap.o
+obj-$(CONFIG_INPUT_MATRIXKMAP)	+= matrix-keymap.o
+obj-$(CONFIG_INPUT_VIVALDIFMAP)	+= vivaldi-fmap.o
+
+obj-$(CONFIG_INPUT_LEDS)	+= input-leds.o
+obj-$(CONFIG_INPUT_MOUSEDEV)	+= mousedev.o
+obj-$(CONFIG_INPUT_JOYDEV)	+= joydev.o
+obj-$(CONFIG_INPUT_EVDEV)	+= evdev.o
+
+obj-$(CONFIG_INPUT_KEYBOARD)	+= keyboard/
+obj-$(CONFIG_INPUT_MOUSE)	+= mouse/
+obj-$(CONFIG_INPUT_JOYSTICK)	+= joystick/
+obj-$(CONFIG_INPUT_TABLET)	+= tablet/
+obj-$(CONFIG_INPUT_TOUCHSCREEN)	+= touchscreen/
+obj-$(CONFIG_INPUT_MISC)	+= misc/
+obj-$(CONFIG_INPUT_KUNIT_TEST)	+= tests/
+
+obj-$(CONFIG_INPUT_APMPOWER)	+= apm-power.o
+
+obj-$(CONFIG_RMI4_CORE)		+= rmi4/