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/gdb/vmlinux-gdb.py | 52 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 scripts/gdb/vmlinux-gdb.py (limited to 'scripts/gdb/vmlinux-gdb.py') diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py new file mode 100644 index 000000000..d4eeed450 --- /dev/null +++ b/scripts/gdb/vmlinux-gdb.py @@ -0,0 +1,52 @@ +# +# gdb helper commands and functions for Linux kernel debugging +# +# loader module +# +# Copyright (c) Siemens AG, 2012, 2013 +# +# Authors: +# Jan Kiszka +# +# This work is licensed under the terms of the GNU GPL version 2. +# + +import os + +sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)) + "/scripts/gdb") + +try: + gdb.parse_and_eval("0") + gdb.execute("", to_string=True) +except: + gdb.write("NOTE: gdb 7.2 or later required for Linux helper scripts to " + "work.\n") +else: + import linux.constants + if linux.constants.LX_CONFIG_DEBUG_INFO_REDUCED: + raise gdb.GdbError("Reduced debug information will prevent GDB " + "from having complete types.\n") + import linux.utils + import linux.symbols + import linux.modules + import linux.dmesg + import linux.tasks + import linux.config + import linux.cpus + import linux.lists + import linux.rbtree + import linux.proc + import linux.timerlist + import linux.clk + import linux.genpd + import linux.device + import linux.vfs + import linux.pgtable + import linux.radixtree + import linux.interrupts + import linux.mm + import linux.stackdepot + import linux.page_owner + import linux.slab + import linux.vmalloc + import linux.kasan -- cgit v1.3.1