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/clocksource/timer-probe.c | 45 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 drivers/clocksource/timer-probe.c (limited to 'drivers/clocksource/timer-probe.c') diff --git a/drivers/clocksource/timer-probe.c b/drivers/clocksource/timer-probe.c new file mode 100644 index 000000000..b7860bc0d --- /dev/null +++ b/drivers/clocksource/timer-probe.c @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved. + */ + +#include +#include +#include +#include + +extern struct of_device_id __timer_of_table[]; + +static const struct of_device_id __timer_of_table_sentinel + __used __section("__timer_of_table_end"); + +void __init timer_probe(void) +{ + struct device_node *np; + const struct of_device_id *match; + of_init_fn_1_ret init_func_ret; + unsigned timers = 0; + int ret; + + for_each_matching_node_and_match(np, __timer_of_table, &match) { + if (!of_device_is_available(np)) + continue; + + init_func_ret = match->data; + + ret = init_func_ret(np); + if (ret) { + if (ret != -EPROBE_DEFER) + pr_err("Failed to initialize '%pOF': %d\n", np, + ret); + continue; + } + + timers++; + } + + timers += acpi_probe_device_table(timer); + + if (!timers) + pr_crit("%s: no matching timers found\n", __func__); +} -- cgit v1.3.1