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, 22 insertions, 0 deletions

diff --git a/drivers/input/rmi4/Makefile b/drivers/input/rmi4/Makefile
new file mode 100644
index 000000000..35ae29f72
--- /dev/null
+++ b/drivers/input/rmi4/Makefile
@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_RMI4_CORE) += rmi_core.o
+rmi_core-y := rmi_bus.o rmi_driver.o rmi_f01.o
+
+rmi_core-$(CONFIG_RMI4_2D_SENSOR) += rmi_2d_sensor.o
+
+# Function drivers
+rmi_core-$(CONFIG_RMI4_F03) += rmi_f03.o
+rmi_core-$(CONFIG_RMI4_F11) += rmi_f11.o
+rmi_core-$(CONFIG_RMI4_F12) += rmi_f12.o
+rmi_core-$(CONFIG_RMI4_F1A) += rmi_f1a.o
+rmi_core-$(CONFIG_RMI4_F21) += rmi_f21.o
+rmi_core-$(CONFIG_RMI4_F30) += rmi_f30.o
+rmi_core-$(CONFIG_RMI4_F34) += rmi_f34.o rmi_f34v7.o
+rmi_core-$(CONFIG_RMI4_F3A) += rmi_f3a.o
+rmi_core-$(CONFIG_RMI4_F54) += rmi_f54.o
+rmi_core-$(CONFIG_RMI4_F55) += rmi_f55.o
+
+# Transports
+obj-$(CONFIG_RMI4_I2C) += rmi_i2c.o
+obj-$(CONFIG_RMI4_SPI) += rmi_spi.o
+obj-$(CONFIG_RMI4_SMB) += rmi_smbus.o