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, 33 insertions, 0 deletions

diff --git a/drivers/pinctrl/sunxi/Makefile b/drivers/pinctrl/sunxi/Makefile
new file mode 100644
index 000000000..951b3f1e4
--- /dev/null
+++ b/drivers/pinctrl/sunxi/Makefile
@@ -0,0 +1,33 @@
+# SPDX-License-Identifier: GPL-2.0
+# Core
+obj-y					+= pinctrl-sunxi.o
+obj-y					+= pinctrl-sunxi-dt.o
+
+# SoC Drivers
+obj-$(CONFIG_PINCTRL_SUNIV_F1C100S)	+= pinctrl-suniv-f1c100s.o
+obj-$(CONFIG_PINCTRL_SUN4I_A10)		+= pinctrl-sun4i-a10.o
+obj-$(CONFIG_PINCTRL_SUN5I)		+= pinctrl-sun5i.o
+obj-$(CONFIG_PINCTRL_SUN6I_A31)		+= pinctrl-sun6i-a31.o
+obj-$(CONFIG_PINCTRL_SUN6I_A31_R)	+= pinctrl-sun6i-a31-r.o
+obj-$(CONFIG_PINCTRL_SUN8I_A23)		+= pinctrl-sun8i-a23.o
+obj-$(CONFIG_PINCTRL_SUN8I_A23_R)	+= pinctrl-sun8i-a23-r.o
+obj-$(CONFIG_PINCTRL_SUN8I_A33)		+= pinctrl-sun8i-a33.o
+obj-$(CONFIG_PINCTRL_SUN50I_A64)	+= pinctrl-sun50i-a64.o
+obj-$(CONFIG_PINCTRL_SUN50I_A64_R)	+= pinctrl-sun50i-a64-r.o
+obj-$(CONFIG_PINCTRL_SUN50I_A100)	+= pinctrl-sun50i-a100.o
+obj-$(CONFIG_PINCTRL_SUN50I_A100_R)	+= pinctrl-sun50i-a100-r.o
+obj-$(CONFIG_PINCTRL_SUN8I_A83T)	+= pinctrl-sun8i-a83t.o
+obj-$(CONFIG_PINCTRL_SUN8I_A83T_R)	+= pinctrl-sun8i-a83t-r.o
+obj-$(CONFIG_PINCTRL_SUN8I_H3)		+= pinctrl-sun8i-h3.o
+obj-$(CONFIG_PINCTRL_SUN8I_H3_R)	+= pinctrl-sun8i-h3-r.o
+obj-$(CONFIG_PINCTRL_SUN8I_V3S)		+= pinctrl-sun8i-v3s.o
+obj-$(CONFIG_PINCTRL_SUN20I_D1)		+= pinctrl-sun20i-d1.o
+obj-$(CONFIG_PINCTRL_SUN50I_H5)		+= pinctrl-sun50i-h5.o
+obj-$(CONFIG_PINCTRL_SUN50I_H6)		+= pinctrl-sun50i-h6.o
+obj-$(CONFIG_PINCTRL_SUN50I_H6_R)	+= pinctrl-sun50i-h6-r.o
+obj-$(CONFIG_PINCTRL_SUN50I_H616)	+= pinctrl-sun50i-h616.o
+obj-$(CONFIG_PINCTRL_SUN50I_H616_R)	+= pinctrl-sun50i-h616-r.o
+obj-$(CONFIG_PINCTRL_SUN55I_A523)	+= pinctrl-sun55i-a523.o
+obj-$(CONFIG_PINCTRL_SUN55I_A523_R)	+= pinctrl-sun55i-a523-r.o
+obj-$(CONFIG_PINCTRL_SUN9I_A80)		+= pinctrl-sun9i-a80.o
+obj-$(CONFIG_PINCTRL_SUN9I_A80_R)	+= pinctrl-sun9i-a80-r.o