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, 100 insertions, 0 deletions

diff --git a/drivers/phy/mediatek/Kconfig b/drivers/phy/mediatek/Kconfig
new file mode 100644
index 000000000..ba6461350
--- /dev/null
+++ b/drivers/phy/mediatek/Kconfig
@@ -0,0 +1,100 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for Mediatek devices
+#
+config PHY_MTK_PCIE
+	tristate "MediaTek PCIe-PHY Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Say 'Y' here to add support for MediaTek PCIe PHY driver.
+	  This driver create the basic PHY instance and provides initialize
+	  callback for PCIe GEN3 port, it supports software efuse
+	  initialization.
+
+config PHY_MTK_XFI_TPHY
+	tristate "MediaTek 10GE SerDes XFI T-PHY driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Say 'Y' here to add support for MediaTek XFI T-PHY driver.
+	  The driver provides access to the Ethernet SerDes T-PHY supporting
+	  1GE and 2.5GE modes via the LynxI PCS, and 5GE and 10GE modes
+	  via the USXGMII PCS found in MediaTek SoCs with 10G Ethernet.
+
+config PHY_MTK_TPHY
+	tristate "MediaTek T-PHY Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF && OF_ADDRESS
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Say 'Y' here to add support for MediaTek T-PHY driver,
+	  it supports multiple usb2.0, usb3.0 ports, PCIe and
+	  SATA, and meanwhile supports two version T-PHY which have
+	  different banks layout, the T-PHY with shared banks between
+	  multi-ports is first version, otherwise is second version,
+	  so you can easily distinguish them by banks layout.
+
+config PHY_MTK_UFS
+	tristate "MediaTek UFS M-PHY driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Support for UFS M-PHY on MediaTek chipsets.
+	  Enable this to provide vendor-specific probing,
+	  initialization, power on and power off flow of
+	  specified M-PHYs.
+
+config PHY_MTK_XSPHY
+	tristate "MediaTek XS-PHY Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF && OF_ADDRESS
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Enable this to support the SuperSpeedPlus XS-PHY transceiver for
+	  USB3.1 GEN2 controllers on MediaTek chips. The driver supports
+	  multiple USB2.0, USB3.1 GEN2 ports.
+
+config PHY_MTK_HDMI
+	tristate "MediaTek HDMI-PHY Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on COMMON_CLK
+	depends on OF
+	depends on REGULATOR
+	select GENERIC_PHY
+	help
+	  Support HDMI PHY for Mediatek SoCs.
+
+config PHY_MTK_MIPI_CSI_0_5
+	tristate "MediaTek MIPI CSI CD-PHY v0.5 Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Enable this to support the MIPI CSI CD-PHY receiver version 0.5.
+	  The driver supports multiple CSI cdphy ports simultaneously.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called phy-mtk-mipi-csi-0-5.
+
+config PHY_MTK_MIPI_DSI
+	tristate "MediaTek MIPI-DSI Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on COMMON_CLK
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Support MIPI DSI for Mediatek SoCs.
+
+config PHY_MTK_DP
+	tristate "MediaTek DP-PHY Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Support DisplayPort PHY for MediaTek SoCs.