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 --- scripts/ld-version.sh | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100755 scripts/ld-version.sh (limited to 'scripts/ld-version.sh') diff --git a/scripts/ld-version.sh b/scripts/ld-version.sh new file mode 100755 index 000000000..b9513d224 --- /dev/null +++ b/scripts/ld-version.sh @@ -0,0 +1,78 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# +# Print the linker name and its version in a 5 or 6-digit form. +# Also, perform the minimum version check. + +set -e + +# Convert the version string x.y.z to a canonical 5 or 6-digit form. +get_canonical_version() +{ + IFS=. + set -- $1 + + # If the 2nd or 3rd field is missing, fill it with a zero. + # + # The 4th field, if present, is ignored. + # This occurs in development snapshots as in 2.35.1.20201116 + echo $((10000 * $1 + 100 * ${2:-0} + ${3:-0})) +} + +orig_args="$@" + +# Get the first line of the --version output. +IFS=' +' +set -- $(LC_ALL=C "$@" --version) + +# Split the line on spaces. +IFS=' ' +set -- $1 + +min_tool_version=$(dirname $0)/min-tool-version.sh + +if [ "$1" = GNU -a "$2" = ld ]; then + shift $(($# - 1)) + version=$1 + min_version=$($min_tool_version binutils) + name=BFD + disp_name="GNU ld" +elif [ "$1" = GNU -a "$2" = gold ]; then + echo "gold linker is not supported as it is not capable of linking the kernel proper." >&2 + exit 1 +else + while [ $# -gt 1 -a "$1" != "LLD" ]; do + shift + done + + if [ "$1" = LLD ]; then + version=$2 + min_version=$($min_tool_version llvm) + name=LLD + disp_name=LLD + else + echo "$orig_args: unknown linker" >&2 + exit 1 + fi +fi + +# There may be something after the version, such as a distribution's package +# release number (like Fedora's "2.34-4.fc32") or punctuation (like LLD briefly +# added before the "compatible with GNU linkers" string), so remove everything +# after just numbers and periods. +version=${version%%[!0-9.]*} + +cversion=$(get_canonical_version $version) +min_cversion=$(get_canonical_version $min_version) + +if [ "$cversion" -lt "$min_cversion" ]; then + echo >&2 "***" + echo >&2 "*** Linker is too old." + echo >&2 "*** Your $disp_name version: $version" + echo >&2 "*** Minimum $disp_name version: $min_version" + echo >&2 "***" + exit 1 +fi + +echo $name $cversion -- cgit v1.3.1