mirror of
https://github.com/torvalds/linux.git
synced 2024-11-10 22:21:40 +00:00
b5b52de321
If a cookie expires from the LRU and the LRU_DISCARD flag is set, but
the state machine has not run yet, it's possible another thread can call
fscache_use_cookie and begin to use it.
When the cookie_worker finally runs, it will see the LRU_DISCARD flag
set, transition the cookie->state to LRU_DISCARDING, which will then
withdraw the cookie. Once the cookie is withdrawn the object is removed
the below oops will occur because the object associated with the cookie
is now NULL.
Fix the oops by clearing the LRU_DISCARD bit if another thread uses the
cookie before the cookie_worker runs.
BUG: kernel NULL pointer dereference, address: 0000000000000008
...
CPU: 31 PID: 44773 Comm: kworker/u130:1 Tainted: G E 6.0.0-5.dneg.x86_64 #1
Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
Workqueue: events_unbound netfs_rreq_write_to_cache_work [netfs]
RIP: 0010:cachefiles_prepare_write+0x28/0x90 [cachefiles]
...
Call Trace:
netfs_rreq_write_to_cache_work+0x11c/0x320 [netfs]
process_one_work+0x217/0x3e0
worker_thread+0x4a/0x3b0
kthread+0xd6/0x100
Fixes: 12bb21a29c ("fscache: Implement cookie user counting and resource pinning")
Reported-by: Daire Byrne <daire.byrne@gmail.com>
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Daire Byrne <daire@dneg.com>
Link: https://lore.kernel.org/r/20221117115023.1350181-1-dwysocha@redhat.com/ # v1
Link: https://lore.kernel.org/r/20221117142915.1366990-1-dwysocha@redhat.com/ # v2
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
504 lines
14 KiB
C
504 lines
14 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
/* FS-Cache tracepoints
|
|
*
|
|
* Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*/
|
|
#undef TRACE_SYSTEM
|
|
#define TRACE_SYSTEM fscache
|
|
|
|
#if !defined(_TRACE_FSCACHE_H) || defined(TRACE_HEADER_MULTI_READ)
|
|
#define _TRACE_FSCACHE_H
|
|
|
|
#include <linux/fscache.h>
|
|
#include <linux/tracepoint.h>
|
|
|
|
/*
|
|
* Define enums for tracing information.
|
|
*/
|
|
#ifndef __FSCACHE_DECLARE_TRACE_ENUMS_ONCE_ONLY
|
|
#define __FSCACHE_DECLARE_TRACE_ENUMS_ONCE_ONLY
|
|
|
|
enum fscache_cache_trace {
|
|
fscache_cache_collision,
|
|
fscache_cache_get_acquire,
|
|
fscache_cache_new_acquire,
|
|
fscache_cache_put_alloc_volume,
|
|
fscache_cache_put_cache,
|
|
fscache_cache_put_prep_failed,
|
|
fscache_cache_put_relinquish,
|
|
fscache_cache_put_volume,
|
|
};
|
|
|
|
enum fscache_volume_trace {
|
|
fscache_volume_collision,
|
|
fscache_volume_get_cookie,
|
|
fscache_volume_get_create_work,
|
|
fscache_volume_get_hash_collision,
|
|
fscache_volume_free,
|
|
fscache_volume_new_acquire,
|
|
fscache_volume_put_cookie,
|
|
fscache_volume_put_create_work,
|
|
fscache_volume_put_hash_collision,
|
|
fscache_volume_put_relinquish,
|
|
fscache_volume_see_create_work,
|
|
fscache_volume_see_hash_wake,
|
|
fscache_volume_wait_create_work,
|
|
};
|
|
|
|
enum fscache_cookie_trace {
|
|
fscache_cookie_collision,
|
|
fscache_cookie_discard,
|
|
fscache_cookie_failed,
|
|
fscache_cookie_get_attach_object,
|
|
fscache_cookie_get_end_access,
|
|
fscache_cookie_get_hash_collision,
|
|
fscache_cookie_get_inval_work,
|
|
fscache_cookie_get_lru,
|
|
fscache_cookie_get_use_work,
|
|
fscache_cookie_new_acquire,
|
|
fscache_cookie_put_hash_collision,
|
|
fscache_cookie_put_lru,
|
|
fscache_cookie_put_object,
|
|
fscache_cookie_put_over_queued,
|
|
fscache_cookie_put_relinquish,
|
|
fscache_cookie_put_withdrawn,
|
|
fscache_cookie_put_work,
|
|
fscache_cookie_see_active,
|
|
fscache_cookie_see_lru_discard,
|
|
fscache_cookie_see_lru_discard_clear,
|
|
fscache_cookie_see_lru_do_one,
|
|
fscache_cookie_see_relinquish,
|
|
fscache_cookie_see_withdraw,
|
|
fscache_cookie_see_work,
|
|
};
|
|
|
|
enum fscache_active_trace {
|
|
fscache_active_use,
|
|
fscache_active_use_modify,
|
|
fscache_active_unuse,
|
|
};
|
|
|
|
enum fscache_access_trace {
|
|
fscache_access_acquire_volume,
|
|
fscache_access_acquire_volume_end,
|
|
fscache_access_cache_pin,
|
|
fscache_access_cache_unpin,
|
|
fscache_access_invalidate_cookie,
|
|
fscache_access_invalidate_cookie_end,
|
|
fscache_access_io_end,
|
|
fscache_access_io_not_live,
|
|
fscache_access_io_read,
|
|
fscache_access_io_resize,
|
|
fscache_access_io_wait,
|
|
fscache_access_io_write,
|
|
fscache_access_lookup_cookie,
|
|
fscache_access_lookup_cookie_end,
|
|
fscache_access_lookup_cookie_end_failed,
|
|
fscache_access_relinquish_volume,
|
|
fscache_access_relinquish_volume_end,
|
|
fscache_access_unlive,
|
|
};
|
|
|
|
#endif
|
|
|
|
/*
|
|
* Declare tracing information enums and their string mappings for display.
|
|
*/
|
|
#define fscache_cache_traces \
|
|
EM(fscache_cache_collision, "*COLLIDE*") \
|
|
EM(fscache_cache_get_acquire, "GET acq ") \
|
|
EM(fscache_cache_new_acquire, "NEW acq ") \
|
|
EM(fscache_cache_put_alloc_volume, "PUT alvol") \
|
|
EM(fscache_cache_put_cache, "PUT cache") \
|
|
EM(fscache_cache_put_prep_failed, "PUT pfail") \
|
|
EM(fscache_cache_put_relinquish, "PUT relnq") \
|
|
E_(fscache_cache_put_volume, "PUT vol ")
|
|
|
|
#define fscache_volume_traces \
|
|
EM(fscache_volume_collision, "*COLLIDE*") \
|
|
EM(fscache_volume_get_cookie, "GET cook ") \
|
|
EM(fscache_volume_get_create_work, "GET creat") \
|
|
EM(fscache_volume_get_hash_collision, "GET hcoll") \
|
|
EM(fscache_volume_free, "FREE ") \
|
|
EM(fscache_volume_new_acquire, "NEW acq ") \
|
|
EM(fscache_volume_put_cookie, "PUT cook ") \
|
|
EM(fscache_volume_put_create_work, "PUT creat") \
|
|
EM(fscache_volume_put_hash_collision, "PUT hcoll") \
|
|
EM(fscache_volume_put_relinquish, "PUT relnq") \
|
|
EM(fscache_volume_see_create_work, "SEE creat") \
|
|
EM(fscache_volume_see_hash_wake, "SEE hwake") \
|
|
E_(fscache_volume_wait_create_work, "WAIT crea")
|
|
|
|
#define fscache_cookie_traces \
|
|
EM(fscache_cookie_collision, "*COLLIDE*") \
|
|
EM(fscache_cookie_discard, "DISCARD ") \
|
|
EM(fscache_cookie_failed, "FAILED ") \
|
|
EM(fscache_cookie_get_attach_object, "GET attch") \
|
|
EM(fscache_cookie_get_hash_collision, "GET hcoll") \
|
|
EM(fscache_cookie_get_end_access, "GQ endac") \
|
|
EM(fscache_cookie_get_inval_work, "GQ inval") \
|
|
EM(fscache_cookie_get_lru, "GET lru ") \
|
|
EM(fscache_cookie_get_use_work, "GQ use ") \
|
|
EM(fscache_cookie_new_acquire, "NEW acq ") \
|
|
EM(fscache_cookie_put_hash_collision, "PUT hcoll") \
|
|
EM(fscache_cookie_put_lru, "PUT lru ") \
|
|
EM(fscache_cookie_put_object, "PUT obj ") \
|
|
EM(fscache_cookie_put_over_queued, "PQ overq") \
|
|
EM(fscache_cookie_put_relinquish, "PUT relnq") \
|
|
EM(fscache_cookie_put_withdrawn, "PUT wthdn") \
|
|
EM(fscache_cookie_put_work, "PQ work ") \
|
|
EM(fscache_cookie_see_active, "- activ") \
|
|
EM(fscache_cookie_see_lru_discard, "- x-lru") \
|
|
EM(fscache_cookie_see_lru_discard_clear,"- lrudc") \
|
|
EM(fscache_cookie_see_lru_do_one, "- lrudo") \
|
|
EM(fscache_cookie_see_relinquish, "- x-rlq") \
|
|
EM(fscache_cookie_see_withdraw, "- x-wth") \
|
|
E_(fscache_cookie_see_work, "- work ")
|
|
|
|
#define fscache_active_traces \
|
|
EM(fscache_active_use, "USE ") \
|
|
EM(fscache_active_use_modify, "USE-m ") \
|
|
E_(fscache_active_unuse, "UNUSE ")
|
|
|
|
#define fscache_access_traces \
|
|
EM(fscache_access_acquire_volume, "BEGIN acq_vol") \
|
|
EM(fscache_access_acquire_volume_end, "END acq_vol") \
|
|
EM(fscache_access_cache_pin, "PIN cache ") \
|
|
EM(fscache_access_cache_unpin, "UNPIN cache ") \
|
|
EM(fscache_access_invalidate_cookie, "BEGIN inval ") \
|
|
EM(fscache_access_invalidate_cookie_end,"END inval ") \
|
|
EM(fscache_access_io_end, "END io ") \
|
|
EM(fscache_access_io_not_live, "END io_notl") \
|
|
EM(fscache_access_io_read, "BEGIN io_read") \
|
|
EM(fscache_access_io_resize, "BEGIN io_resz") \
|
|
EM(fscache_access_io_wait, "WAIT io ") \
|
|
EM(fscache_access_io_write, "BEGIN io_writ") \
|
|
EM(fscache_access_lookup_cookie, "BEGIN lookup ") \
|
|
EM(fscache_access_lookup_cookie_end, "END lookup ") \
|
|
EM(fscache_access_lookup_cookie_end_failed,"END lookupf") \
|
|
EM(fscache_access_relinquish_volume, "BEGIN rlq_vol") \
|
|
EM(fscache_access_relinquish_volume_end,"END rlq_vol") \
|
|
E_(fscache_access_unlive, "END unlive ")
|
|
|
|
/*
|
|
* Export enum symbols via userspace.
|
|
*/
|
|
#undef EM
|
|
#undef E_
|
|
#define EM(a, b) TRACE_DEFINE_ENUM(a);
|
|
#define E_(a, b) TRACE_DEFINE_ENUM(a);
|
|
|
|
fscache_cache_traces;
|
|
fscache_volume_traces;
|
|
fscache_cookie_traces;
|
|
fscache_access_traces;
|
|
|
|
/*
|
|
* Now redefine the EM() and E_() macros to map the enums to the strings that
|
|
* will be printed in the output.
|
|
*/
|
|
#undef EM
|
|
#undef E_
|
|
#define EM(a, b) { a, b },
|
|
#define E_(a, b) { a, b }
|
|
|
|
|
|
TRACE_EVENT(fscache_cache,
|
|
TP_PROTO(unsigned int cache_debug_id,
|
|
int usage,
|
|
enum fscache_cache_trace where),
|
|
|
|
TP_ARGS(cache_debug_id, usage, where),
|
|
|
|
TP_STRUCT__entry(
|
|
__field(unsigned int, cache )
|
|
__field(int, usage )
|
|
__field(enum fscache_cache_trace, where )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->cache = cache_debug_id;
|
|
__entry->usage = usage;
|
|
__entry->where = where;
|
|
),
|
|
|
|
TP_printk("C=%08x %s r=%d",
|
|
__entry->cache,
|
|
__print_symbolic(__entry->where, fscache_cache_traces),
|
|
__entry->usage)
|
|
);
|
|
|
|
TRACE_EVENT(fscache_volume,
|
|
TP_PROTO(unsigned int volume_debug_id,
|
|
int usage,
|
|
enum fscache_volume_trace where),
|
|
|
|
TP_ARGS(volume_debug_id, usage, where),
|
|
|
|
TP_STRUCT__entry(
|
|
__field(unsigned int, volume )
|
|
__field(int, usage )
|
|
__field(enum fscache_volume_trace, where )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->volume = volume_debug_id;
|
|
__entry->usage = usage;
|
|
__entry->where = where;
|
|
),
|
|
|
|
TP_printk("V=%08x %s u=%d",
|
|
__entry->volume,
|
|
__print_symbolic(__entry->where, fscache_volume_traces),
|
|
__entry->usage)
|
|
);
|
|
|
|
TRACE_EVENT(fscache_cookie,
|
|
TP_PROTO(unsigned int cookie_debug_id,
|
|
int ref,
|
|
enum fscache_cookie_trace where),
|
|
|
|
TP_ARGS(cookie_debug_id, ref, where),
|
|
|
|
TP_STRUCT__entry(
|
|
__field(unsigned int, cookie )
|
|
__field(int, ref )
|
|
__field(enum fscache_cookie_trace, where )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->cookie = cookie_debug_id;
|
|
__entry->ref = ref;
|
|
__entry->where = where;
|
|
),
|
|
|
|
TP_printk("c=%08x %s r=%d",
|
|
__entry->cookie,
|
|
__print_symbolic(__entry->where, fscache_cookie_traces),
|
|
__entry->ref)
|
|
);
|
|
|
|
TRACE_EVENT(fscache_active,
|
|
TP_PROTO(unsigned int cookie_debug_id,
|
|
int ref,
|
|
int n_active,
|
|
int n_accesses,
|
|
enum fscache_active_trace why),
|
|
|
|
TP_ARGS(cookie_debug_id, ref, n_active, n_accesses, why),
|
|
|
|
TP_STRUCT__entry(
|
|
__field(unsigned int, cookie )
|
|
__field(int, ref )
|
|
__field(int, n_active )
|
|
__field(int, n_accesses )
|
|
__field(enum fscache_active_trace, why )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->cookie = cookie_debug_id;
|
|
__entry->ref = ref;
|
|
__entry->n_active = n_active;
|
|
__entry->n_accesses = n_accesses;
|
|
__entry->why = why;
|
|
),
|
|
|
|
TP_printk("c=%08x %s r=%d a=%d c=%d",
|
|
__entry->cookie,
|
|
__print_symbolic(__entry->why, fscache_active_traces),
|
|
__entry->ref,
|
|
__entry->n_accesses,
|
|
__entry->n_active)
|
|
);
|
|
|
|
TRACE_EVENT(fscache_access_cache,
|
|
TP_PROTO(unsigned int cache_debug_id,
|
|
int ref,
|
|
int n_accesses,
|
|
enum fscache_access_trace why),
|
|
|
|
TP_ARGS(cache_debug_id, ref, n_accesses, why),
|
|
|
|
TP_STRUCT__entry(
|
|
__field(unsigned int, cache )
|
|
__field(int, ref )
|
|
__field(int, n_accesses )
|
|
__field(enum fscache_access_trace, why )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->cache = cache_debug_id;
|
|
__entry->ref = ref;
|
|
__entry->n_accesses = n_accesses;
|
|
__entry->why = why;
|
|
),
|
|
|
|
TP_printk("C=%08x %s r=%d a=%d",
|
|
__entry->cache,
|
|
__print_symbolic(__entry->why, fscache_access_traces),
|
|
__entry->ref,
|
|
__entry->n_accesses)
|
|
);
|
|
|
|
TRACE_EVENT(fscache_access_volume,
|
|
TP_PROTO(unsigned int volume_debug_id,
|
|
unsigned int cookie_debug_id,
|
|
int ref,
|
|
int n_accesses,
|
|
enum fscache_access_trace why),
|
|
|
|
TP_ARGS(volume_debug_id, cookie_debug_id, ref, n_accesses, why),
|
|
|
|
TP_STRUCT__entry(
|
|
__field(unsigned int, volume )
|
|
__field(unsigned int, cookie )
|
|
__field(int, ref )
|
|
__field(int, n_accesses )
|
|
__field(enum fscache_access_trace, why )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->volume = volume_debug_id;
|
|
__entry->cookie = cookie_debug_id;
|
|
__entry->ref = ref;
|
|
__entry->n_accesses = n_accesses;
|
|
__entry->why = why;
|
|
),
|
|
|
|
TP_printk("V=%08x c=%08x %s r=%d a=%d",
|
|
__entry->volume,
|
|
__entry->cookie,
|
|
__print_symbolic(__entry->why, fscache_access_traces),
|
|
__entry->ref,
|
|
__entry->n_accesses)
|
|
);
|
|
|
|
TRACE_EVENT(fscache_access,
|
|
TP_PROTO(unsigned int cookie_debug_id,
|
|
int ref,
|
|
int n_accesses,
|
|
enum fscache_access_trace why),
|
|
|
|
TP_ARGS(cookie_debug_id, ref, n_accesses, why),
|
|
|
|
TP_STRUCT__entry(
|
|
__field(unsigned int, cookie )
|
|
__field(int, ref )
|
|
__field(int, n_accesses )
|
|
__field(enum fscache_access_trace, why )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->cookie = cookie_debug_id;
|
|
__entry->ref = ref;
|
|
__entry->n_accesses = n_accesses;
|
|
__entry->why = why;
|
|
),
|
|
|
|
TP_printk("c=%08x %s r=%d a=%d",
|
|
__entry->cookie,
|
|
__print_symbolic(__entry->why, fscache_access_traces),
|
|
__entry->ref,
|
|
__entry->n_accesses)
|
|
);
|
|
|
|
TRACE_EVENT(fscache_acquire,
|
|
TP_PROTO(struct fscache_cookie *cookie),
|
|
|
|
TP_ARGS(cookie),
|
|
|
|
TP_STRUCT__entry(
|
|
__field(unsigned int, cookie )
|
|
__field(unsigned int, volume )
|
|
__field(int, v_ref )
|
|
__field(int, v_n_cookies )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->cookie = cookie->debug_id;
|
|
__entry->volume = cookie->volume->debug_id;
|
|
__entry->v_ref = refcount_read(&cookie->volume->ref);
|
|
__entry->v_n_cookies = atomic_read(&cookie->volume->n_cookies);
|
|
),
|
|
|
|
TP_printk("c=%08x V=%08x vr=%d vc=%d",
|
|
__entry->cookie,
|
|
__entry->volume, __entry->v_ref, __entry->v_n_cookies)
|
|
);
|
|
|
|
TRACE_EVENT(fscache_relinquish,
|
|
TP_PROTO(struct fscache_cookie *cookie, bool retire),
|
|
|
|
TP_ARGS(cookie, retire),
|
|
|
|
TP_STRUCT__entry(
|
|
__field(unsigned int, cookie )
|
|
__field(unsigned int, volume )
|
|
__field(int, ref )
|
|
__field(int, n_active )
|
|
__field(u8, flags )
|
|
__field(bool, retire )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->cookie = cookie->debug_id;
|
|
__entry->volume = cookie->volume->debug_id;
|
|
__entry->ref = refcount_read(&cookie->ref);
|
|
__entry->n_active = atomic_read(&cookie->n_active);
|
|
__entry->flags = cookie->flags;
|
|
__entry->retire = retire;
|
|
),
|
|
|
|
TP_printk("c=%08x V=%08x r=%d U=%d f=%02x rt=%u",
|
|
__entry->cookie, __entry->volume, __entry->ref,
|
|
__entry->n_active, __entry->flags, __entry->retire)
|
|
);
|
|
|
|
TRACE_EVENT(fscache_invalidate,
|
|
TP_PROTO(struct fscache_cookie *cookie, loff_t new_size),
|
|
|
|
TP_ARGS(cookie, new_size),
|
|
|
|
TP_STRUCT__entry(
|
|
__field(unsigned int, cookie )
|
|
__field(loff_t, new_size )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->cookie = cookie->debug_id;
|
|
__entry->new_size = new_size;
|
|
),
|
|
|
|
TP_printk("c=%08x sz=%llx",
|
|
__entry->cookie, __entry->new_size)
|
|
);
|
|
|
|
TRACE_EVENT(fscache_resize,
|
|
TP_PROTO(struct fscache_cookie *cookie, loff_t new_size),
|
|
|
|
TP_ARGS(cookie, new_size),
|
|
|
|
TP_STRUCT__entry(
|
|
__field(unsigned int, cookie )
|
|
__field(loff_t, old_size )
|
|
__field(loff_t, new_size )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->cookie = cookie->debug_id;
|
|
__entry->old_size = cookie->object_size;
|
|
__entry->new_size = new_size;
|
|
),
|
|
|
|
TP_printk("c=%08x os=%08llx sz=%08llx",
|
|
__entry->cookie,
|
|
__entry->old_size,
|
|
__entry->new_size)
|
|
);
|
|
|
|
#endif /* _TRACE_FSCACHE_H */
|
|
|
|
/* This part must be outside protection */
|
|
#include <trace/define_trace.h>
|