From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- fs/netfs/fscache_stats.c | 103 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) create mode 100644 fs/netfs/fscache_stats.c (limited to 'fs/netfs/fscache_stats.c') diff --git a/fs/netfs/fscache_stats.c b/fs/netfs/fscache_stats.c new file mode 100644 index 000000000..add21abdf --- /dev/null +++ b/fs/netfs/fscache_stats.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* FS-Cache statistics + * + * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#define FSCACHE_DEBUG_LEVEL CACHE +#include +#include +#include "internal.h" + +/* + * operation counters + */ +atomic_t fscache_n_volumes; +atomic_t fscache_n_volumes_collision; +atomic_t fscache_n_volumes_nomem; +atomic_t fscache_n_cookies; +atomic_t fscache_n_cookies_lru; +atomic_t fscache_n_cookies_lru_expired; +atomic_t fscache_n_cookies_lru_removed; +atomic_t fscache_n_cookies_lru_dropped; + +atomic_t fscache_n_acquires; +atomic_t fscache_n_acquires_ok; +atomic_t fscache_n_acquires_oom; + +atomic_t fscache_n_invalidates; + +atomic_t fscache_n_updates; +EXPORT_SYMBOL(fscache_n_updates); + +atomic_t fscache_n_relinquishes; +atomic_t fscache_n_relinquishes_retire; +atomic_t fscache_n_relinquishes_dropped; + +atomic_t fscache_n_resizes; +atomic_t fscache_n_resizes_null; + +atomic_t fscache_n_read; +EXPORT_SYMBOL(fscache_n_read); +atomic_t fscache_n_write; +EXPORT_SYMBOL(fscache_n_write); +atomic_t fscache_n_no_write_space; +EXPORT_SYMBOL(fscache_n_no_write_space); +atomic_t fscache_n_no_create_space; +EXPORT_SYMBOL(fscache_n_no_create_space); +atomic_t fscache_n_culled; +EXPORT_SYMBOL(fscache_n_culled); +atomic_t fscache_n_dio_misfit; +EXPORT_SYMBOL(fscache_n_dio_misfit); + +/* + * display the general statistics + */ +int fscache_stats_show(struct seq_file *m) +{ + seq_puts(m, "-- FS-Cache statistics --\n"); + seq_printf(m, "Cookies: n=%d v=%d vcol=%u voom=%u\n", + atomic_read(&fscache_n_cookies), + atomic_read(&fscache_n_volumes), + atomic_read(&fscache_n_volumes_collision), + atomic_read(&fscache_n_volumes_nomem) + ); + + seq_printf(m, "Acquire: n=%u ok=%u oom=%u\n", + atomic_read(&fscache_n_acquires), + atomic_read(&fscache_n_acquires_ok), + atomic_read(&fscache_n_acquires_oom)); + + seq_printf(m, "LRU : n=%u exp=%u rmv=%u drp=%u at=%ld\n", + atomic_read(&fscache_n_cookies_lru), + atomic_read(&fscache_n_cookies_lru_expired), + atomic_read(&fscache_n_cookies_lru_removed), + atomic_read(&fscache_n_cookies_lru_dropped), + timer_pending(&fscache_cookie_lru_timer) ? + fscache_cookie_lru_timer.expires - jiffies : 0); + + seq_printf(m, "Invals : n=%u\n", + atomic_read(&fscache_n_invalidates)); + + seq_printf(m, "Updates: n=%u rsz=%u rsn=%u\n", + atomic_read(&fscache_n_updates), + atomic_read(&fscache_n_resizes), + atomic_read(&fscache_n_resizes_null)); + + seq_printf(m, "Relinqs: n=%u rtr=%u drop=%u\n", + atomic_read(&fscache_n_relinquishes), + atomic_read(&fscache_n_relinquishes_retire), + atomic_read(&fscache_n_relinquishes_dropped)); + + seq_printf(m, "NoSpace: nwr=%u ncr=%u cull=%u\n", + atomic_read(&fscache_n_no_write_space), + atomic_read(&fscache_n_no_create_space), + atomic_read(&fscache_n_culled)); + + seq_printf(m, "IO : rd=%u wr=%u mis=%u\n", + atomic_read(&fscache_n_read), + atomic_read(&fscache_n_write), + atomic_read(&fscache_n_dio_misfit)); + return 0; +} -- cgit v1.3.1