From dd05add7b2b6004c5fa3a1f276f56d8668f86b65 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Sat, 26 Sep 2026 19:20:30 -0300 Subject: netfs: zero the tail of a short DIO/unbuffered read 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 Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: Christian Brauner Cc: Matthew Wilcox Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Bharath SM Cc: stable@vger.kernel.org --- drivers/tty/serdev/Kconfig | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 drivers/tty/serdev/Kconfig (limited to 'drivers/tty/serdev/Kconfig') diff --git a/drivers/tty/serdev/Kconfig b/drivers/tty/serdev/Kconfig new file mode 100644 index 000000000..e6dfe949a --- /dev/null +++ b/drivers/tty/serdev/Kconfig @@ -0,0 +1,32 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Serial bus device driver configuration +# +menuconfig SERIAL_DEV_BUS + tristate "Serial device bus" + help + Core support for devices connected via a serial port. + + Note that you typically also want to enable TTY port controller support. + +config RUST_SERIAL_DEV_BUS_ABSTRACTIONS + bool "Rust Serial device bus abstractions" + depends on RUST + select SERIAL_DEV_BUS + help + This enables the Rust abstraction for the serial device bus API. + +if SERIAL_DEV_BUS + +config SERIAL_DEV_CTRL_TTYPORT + bool "Serial device TTY port controller" + help + Say Y here if you want to use the Serial device bus with common TTY + drivers (e.g. serial drivers). + + If unsure, say Y. + depends on TTY + depends on SERIAL_DEV_BUS != m + default y + +endif -- cgit v1.3.1