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, 25 insertions, 0 deletions

diff --git a/drivers/phy/mediatek/Makefile b/drivers/phy/mediatek/Makefile
new file mode 100644
index 000000000..ed0da7087
--- /dev/null
+++ b/drivers/phy/mediatek/Makefile
@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the phy drivers.
+#
+
+obj-$(CONFIG_PHY_MTK_DP)		+= phy-mtk-dp.o
+obj-$(CONFIG_PHY_MTK_PCIE)		+= phy-mtk-pcie.o
+obj-$(CONFIG_PHY_MTK_TPHY)		+= phy-mtk-tphy.o
+obj-$(CONFIG_PHY_MTK_UFS)		+= phy-mtk-ufs.o
+obj-$(CONFIG_PHY_MTK_XSPHY)		+= phy-mtk-xsphy.o
+obj-$(CONFIG_PHY_MTK_XFI_TPHY)		+= phy-mtk-xfi-tphy.o
+
+phy-mtk-hdmi-drv-y			:= phy-mtk-hdmi.o
+phy-mtk-hdmi-drv-y			+= phy-mtk-hdmi-mt2701.o
+phy-mtk-hdmi-drv-y			+= phy-mtk-hdmi-mt8173.o
+phy-mtk-hdmi-drv-y			+= phy-mtk-hdmi-mt8195.o
+obj-$(CONFIG_PHY_MTK_HDMI)		+= phy-mtk-hdmi-drv.o
+
+obj-$(CONFIG_PHY_MTK_MIPI_CSI_0_5)	+= phy-mtk-mipi-csi-0-5.o
+
+phy-mtk-mipi-dsi-drv-y			:= phy-mtk-mipi-dsi.o
+phy-mtk-mipi-dsi-drv-y			+= phy-mtk-mipi-dsi-mt8173.o
+phy-mtk-mipi-dsi-drv-y			+= phy-mtk-mipi-dsi-mt8183.o
+phy-mtk-mipi-dsi-drv-y			+= phy-mtk-mipi-dsi-mt8196.o
+obj-$(CONFIG_PHY_MTK_MIPI_DSI)		+= phy-mtk-mipi-dsi-drv.o