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, 56 insertions, 0 deletions

diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
new file mode 100644
index 000000000..45ad17062
--- /dev/null
+++ b/drivers/reset/Makefile
@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-y += core.o
+obj-y += amlogic/
+obj-y += hisilicon/
+obj-y += spacemit/
+obj-y += starfive/
+obj-y += sti/
+obj-y += tegra/
+obj-$(CONFIG_RESET_A10SR) += reset-a10sr.o
+obj-$(CONFIG_RESET_ASPEED) += reset-aspeed.o
+obj-$(CONFIG_RESET_ATH79) += reset-ath79.o
+obj-$(CONFIG_RESET_AXS10X) += reset-axs10x.o
+obj-$(CONFIG_RESET_BCM6345) += reset-bcm6345.o
+obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o
+obj-$(CONFIG_RESET_BRCMSTB) += reset-brcmstb.o
+obj-$(CONFIG_RESET_BRCMSTB_RESCAL) += reset-brcmstb-rescal.o
+obj-$(CONFIG_RESET_EIC7700) += reset-eic7700.o
+obj-$(CONFIG_RESET_EIC7700_HSP) += reset-eic7700-hsp.o
+obj-$(CONFIG_RESET_EYEQ) += reset-eyeq.o
+obj-$(CONFIG_RESET_GPIO) += reset-gpio.o
+obj-$(CONFIG_RESET_HSDK) += reset-hsdk.o
+obj-$(CONFIG_RESET_IMX_SCU) += reset-imx-scu.o
+obj-$(CONFIG_RESET_IMX7) += reset-imx7.o
+obj-$(CONFIG_RESET_IMX8MP_AUDIOMIX) += reset-imx8mp-audiomix.o
+obj-$(CONFIG_RESET_INTEL_GW) += reset-intel-gw.o
+obj-$(CONFIG_RESET_K210) += reset-k210.o
+obj-$(CONFIG_RESET_K230) += reset-k230.o
+obj-$(CONFIG_RESET_LANTIQ) += reset-lantiq.o
+obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o
+obj-$(CONFIG_RESET_MCHP_SPARX5) += reset-microchip-sparx5.o
+obj-$(CONFIG_RESET_NPCM) += reset-npcm.o
+obj-$(CONFIG_RESET_NUVOTON_MA35D1) += reset-ma35d1.o
+obj-$(CONFIG_RESET_PISTACHIO) += reset-pistachio.o
+obj-$(CONFIG_RESET_POLARFIRE_SOC) += reset-mpfs.o
+obj-$(CONFIG_RESET_QCOM_AOSS) += reset-qcom-aoss.o
+obj-$(CONFIG_RESET_QCOM_PDC) += reset-qcom-pdc.o
+obj-$(CONFIG_RESET_RASPBERRYPI) += reset-raspberrypi.o
+obj-$(CONFIG_RESET_RZG2L_USBPHY_CTRL) += reset-rzg2l-usbphy-ctrl.o
+obj-$(CONFIG_RESET_RZV2H_USB2PHY) += reset-rzv2h-usb2phy.o
+obj-$(CONFIG_RESET_SCMI) += reset-scmi.o
+obj-$(CONFIG_RESET_SIMPLE) += reset-simple.o
+obj-$(CONFIG_RESET_SKY1) += reset-sky1.o
+obj-$(CONFIG_RESET_SKY1_AUDSS) += reset-sky1-audss.o
+obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o
+obj-$(CONFIG_RESET_SUNPLUS) += reset-sunplus.o
+obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
+obj-$(CONFIG_RESET_TENSTORRENT_ATLANTIS) += reset-tenstorrent-atlantis.o
+obj-$(CONFIG_RESET_TH1520) += reset-th1520.o
+obj-$(CONFIG_RESET_TI_SCI) += reset-ti-sci.o
+obj-$(CONFIG_RESET_TI_SYSCON) += reset-ti-syscon.o
+obj-$(CONFIG_RESET_TI_TPS380X) += reset-tps380x.o
+obj-$(CONFIG_RESET_TN48M_CPLD) += reset-tn48m.o
+obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
+obj-$(CONFIG_RESET_UNIPHIER_GLUE) += reset-uniphier-glue.o
+obj-$(CONFIG_RESET_ZYNQ) += reset-zynq.o
+obj-$(CONFIG_RESET_ZYNQMP) += reset-zynqmp.o