Viewing: tracefile.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
*
* Copyright (c) 2012, 2017, Intel Corporation.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
*
* Author: Zach Brown <zab@clusterfs.com>
* Author: Phil Schwan <phil@clusterfs.com>
*/
#define DEBUG_SUBSYSTEM S_LNET
#include "tracefile.h"
#include <linux/ctype.h>
#include <linux/fs.h>
#include <linux/kthread.h>
#include <linux/pagemap.h>
#include <linux/poll.h>
#include <linux/uaccess.h>
#include <lustre_compat/linux/mm.h>
#include <linux/libcfs/libcfs.h>
enum cfs_trace_buf_type {
CFS_TCD_TYPE_PROC = 0,
CFS_TCD_TYPE_SOFTIRQ,
CFS_TCD_TYPE_IRQ,
CFS_TCD_TYPE_CNT
};
static union cfs_trace_data_union (*cfs_trace_data[CFS_TCD_TYPE_CNT])[NR_CPUS] __cacheline_aligned;
/* Pages containing records already processed by daemon.
* Link via ->lru, use size in ->private
*/
static LIST_HEAD(daemon_pages);
static long daemon_pages_count;
static long daemon_pages_max;
char cfs_tracefile[TRACEFILE_NAME_SIZE];
long long cfs_tracefile_size = CFS_TRACEFILE_SIZE;
static struct task_struct *tctl_task;
static atomic_t cfs_tage_allocated = ATOMIC_INIT(0);
static DECLARE_RWSEM(cfs_tracefile_sem);
/* trace file lock routines */
/* The walking argument indicates the locking comes from all tcd types
* iterator and we must lock it and dissable local irqs to avoid deadlocks
* with other interrupt locks that might be happening. See LU-1311
* for details.
*/
static int cfs_trace_lock_tcd(struct cfs_trace_cpu_data *tcd, int walking)
__acquires(&tcd->tcd_lock)
{
__LASSERT(tcd->tcd_type < CFS_TCD_TYPE_CNT);
if (tcd->tcd_type == CFS_TCD_TYPE_IRQ)
spin_lock_irqsave(&tcd->tcd_lock, tcd->tcd_lock_flags);
else if (tcd->tcd_type == CFS_TCD_TYPE_SOFTIRQ)
spin_lock_bh(&tcd->tcd_lock);
else if (unlikely(walking))
spin_lock_irq(&tcd->tcd_lock);
else
spin_lock(&tcd->tcd_lock);
return 1;
}
static void cfs_trace_unlock_tcd(struct cfs_trace_cpu_data *tcd, int walking)
__releases(&tcd->tcd_lock)
{
__LASSERT(tcd->tcd_type < CFS_TCD_TYPE_CNT);
if (tcd->tcd_type == CFS_TCD_TYPE_IRQ)
spin_unlock_irqrestore(&tcd->tcd_lock, tcd->tcd_lock_flags);
else if (tcd->tcd_type == CFS_TCD_TYPE_SOFTIRQ)
spin_unlock_bh(&tcd->tcd_lock);
else if (unlikely(walking))
spin_unlock_irq(&tcd->tcd_lock);
else
spin_unlock(&tcd->tcd_lock);
}
#define cfs_tcd_for_each(tcd, i, j) \
for (i = 0; i < CFS_TCD_TYPE_CNT && cfs_trace_data[i]; i++) \
for (j = 0, ((tcd) = &(*cfs_trace_data[i])[j].tcd); \
j < num_possible_cpus(); \
j++, (tcd) = &(*cfs_trace_data[i])[j].tcd)
#define cfs_tcd_for_each_type_lock(tcd, i, cpu) \
for (i = 0; i < CFS_TCD_TYPE_CNT && cfs_trace_data[i] && \
(tcd = &(*cfs_trace_data[i])[cpu].tcd) && \
cfs_trace_lock_tcd(tcd, 1); cfs_trace_unlock_tcd(tcd, 1), i++)
static enum cfs_trace_buf_type cfs_trace_buf_idx_get(void)
{
if (in_hardirq())
return CFS_TCD_TYPE_IRQ;
if (in_softirq())
return CFS_TCD_TYPE_SOFTIRQ;
return CFS_TCD_TYPE_PROC;
}
static inline struct cfs_trace_cpu_data *
cfs_trace_get_tcd(void)
{
struct cfs_trace_cpu_data *tcd =
&(*cfs_trace_data[cfs_trace_buf_idx_get()])[get_cpu()].tcd;
cfs_trace_lock_tcd(tcd, 0);
return tcd;
}
static inline void cfs_trace_put_tcd(struct cfs_trace_cpu_data *tcd)
{
cfs_trace_unlock_tcd(tcd, 0);
put_cpu();
}
static inline struct cfs_trace_page *
cfs_tage_from_list(struct list_head *list)
{
return list_entry(list, struct cfs_trace_page, linkage);
}
static struct cfs_trace_page *cfs_tage_alloc(gfp_t gfp)
{
struct page *page;
struct cfs_trace_page *tage;
/* My caller is trying to free memory */
if (!in_interrupt() && (current->flags & PF_MEMALLOC))
return NULL;
/*
* Don't spam console with allocation failures: they will be reported
* by upper layer anyway.
*/
gfp |= __GFP_NOWARN;
page = alloc_page(gfp);
if (page == NULL)
return NULL;
tage = kmalloc(sizeof(*tage), gfp);
if (tage == NULL) {
__free_page(page);
return NULL;
}
tage->page = page;
atomic_inc(&cfs_tage_allocated);
return tage;
}
static void cfs_tage_free(struct cfs_trace_page *tage)
{
__LASSERT(tage != NULL);
__LASSERT(tage->page != NULL);
__free_page(tage->page);
kfree(tage);
atomic_dec(&cfs_tage_allocated);
}
static void cfs_tage_to_tail(struct cfs_trace_page *tage,
struct list_head *queue)
{
__LASSERT(tage != NULL);
__LASSERT(queue != NULL);
list_move_tail(&tage->linkage, queue);
}
/* return a page that has 'len' bytes left at the end */
static struct cfs_trace_page *
cfs_trace_get_tage_try(struct cfs_trace_cpu_data *tcd, unsigned long len)
{
struct cfs_trace_page *tage;
struct task_struct *tsk;
if (tcd->tcd_cur_pages > 0) {
__LASSERT(!list_empty(&tcd->tcd_pages));
tage = cfs_tage_from_list(tcd->tcd_pages.prev);
if (tage->used + len <= PAGE_SIZE)
return tage;
}
if (tcd->tcd_cur_pages < tcd->tcd_max_pages) {
if (tcd->tcd_cur_stock_pages > 0) {
tage = cfs_tage_from_list(tcd->tcd_stock_pages.prev);
--tcd->tcd_cur_stock_pages;
list_del_init(&tage->linkage);
} else {
tage = cfs_tage_alloc(GFP_ATOMIC);
if (unlikely(tage == NULL)) {
if ((!(current->flags & PF_MEMALLOC) ||
in_interrupt()) && printk_ratelimit())
pr_warn("Lustre: cannot allocate a tage (%ld)\n",
tcd->tcd_cur_pages);
return NULL;
}
}
tage->used = 0;
tage->cpu = smp_processor_id();
tage->type = tcd->tcd_type;
list_add_tail(&tage->linkage, &tcd->tcd_pages);
tcd->tcd_cur_pages++;
tsk = tctl_task;
if (tcd->tcd_cur_pages > 8 && tsk)
/*
* wake up tracefiled to process some pages.
*/
wake_up_process(tsk);
return tage;
}
return NULL;
}
static void cfs_tcd_shrink(struct cfs_trace_cpu_data *tcd)
{
int pgcount = tcd->tcd_cur_pages / 10;
struct page_collection pc;
struct cfs_trace_page *tage;
struct cfs_trace_page *tmp;
/*
* XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
* from here: this will lead to infinite recursion.
*/
if (printk_ratelimit())
pr_warn("Lustre: debug daemon buffer overflowed; discarding 10%% of pages (%d of %ld)\n",
pgcount + 1, tcd->tcd_cur_pages);
INIT_LIST_HEAD(&pc.pc_pages);
list_for_each_entry_safe(tage, tmp, &tcd->tcd_pages, linkage) {
if (pgcount-- == 0)
break;
list_del(&tage->linkage);
cfs_tage_free(tage);
tcd->tcd_cur_pages--;
}
}
/* return a page that has 'len' bytes left at the end */
static struct cfs_trace_page *cfs_trace_get_tage(struct cfs_trace_cpu_data *tcd,
unsigned long len)
{
struct cfs_trace_page *tage;
/*
* XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
* from here: this will lead to infinite recursion.
*/
if (len > PAGE_SIZE) {
pr_err("LustreError: cowardly refusing to write %lu bytes in a page\n",
len);
return NULL;
}
tage = cfs_trace_get_tage_try(tcd, len);
if (tage != NULL)
return tage;
if (tctl_task)
cfs_tcd_shrink(tcd);
if (tcd->tcd_cur_pages > 0) {
tage = cfs_tage_from_list(tcd->tcd_pages.next);
tage->used = 0;
cfs_tage_to_tail(tage, &tcd->tcd_pages);
}
return tage;
}
static void cfs_set_ptldebug_header(struct ptldebug_header *header,
struct libcfs_debug_msg_data *msgdata)
{
struct timespec64 ts;
ktime_get_real_ts64(&ts);
header->ph_subsys = msgdata->msg_subsys;
header->ph_mask = msgdata->msg_mask;
header->ph_cpu_id = smp_processor_id();
header->ph_type = cfs_trace_buf_idx_get();
/* y2038 safe since all user space treats this as unsigned, but
* will overflow in 2106
*/
header->ph_sec = (u32)ts.tv_sec;
header->ph_usec = ts.tv_nsec / NSEC_PER_USEC;
header->ph_pid = current->pid;
header->ph_line_num = msgdata->msg_line;
header->ph_extern_pid = 0;
}
static void cfs_vprint_to_console(struct ptldebug_header *hdr,
struct va_format *vaf, const char *file,
const char *fn)
{
int subsys = hdr->ph_subsys;
int mask = hdr->ph_mask;
char *prefix = "Lustre";
if (subsys == S_LND || subsys == S_LNET)
prefix = "LNet";
if (mask & D_CONSOLE) {
if (mask & D_EMERG)
pr_emerg("%sError: %pV", prefix, vaf);
else if (mask & D_ERROR)
pr_err("%sError: %pV", prefix, vaf);
else if (mask & D_WARNING)
pr_warn("%s: %pV", prefix, vaf);
else if (mask & libcfs_printk ||
subsys & libcfs_subsystem_printk)
pr_info("%s: %pV", prefix, vaf);
} else {
if (mask & D_EMERG)
pr_emerg("%sError: %d:%d:(%s:%d:%s()) %pV", prefix,
hdr->ph_pid, hdr->ph_extern_pid, file,
hdr->ph_line_num, fn, vaf);
else if (mask & D_ERROR)
pr_err("%sError: %d:%d:(%s:%d:%s()) %pV", prefix,
hdr->ph_pid, hdr->ph_extern_pid, file,
hdr->ph_line_num, fn, vaf);
else if (mask & D_WARNING)
pr_warn("%s: %d:%d:(%s:%d:%s()) %pV", prefix,
hdr->ph_pid, hdr->ph_extern_pid, file,
hdr->ph_line_num, fn, vaf);
else if (mask & libcfs_printk ||
subsys & libcfs_subsystem_printk)
pr_info("%s: %d:%d:(%s:%d:%s()) %pV", prefix,
hdr->ph_pid, hdr->ph_extern_pid, file,
hdr->ph_line_num, fn, vaf);
}
}
static void cfs_print_to_console(struct ptldebug_header *hdr, const char *file,
const char *fn, const char *fmt, ...)
{
struct va_format vaf;
va_list args;
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
cfs_vprint_to_console(hdr, &vaf, file, fn);
}
#define DEBUG_FORMAT_BUFFER_SIZE (256 - sizeof(unsigned long))
struct debug_format_buffer {
unsigned long dfb_flags;
char dfb_buf[DEBUG_FORMAT_BUFFER_SIZE];
};
struct pcpu_format_pool {
struct debug_format_buffer pf_dfb[4096 / DEBUG_FORMAT_BUFFER_SIZE];
};
enum pool_flags {
PF_INUSE,
};
static struct pcpu_format_pool __percpu *debug_format_pool;
int debug_format_buffer_alloc_buffers(void)
{
struct pcpu_format_pool __percpu *obj;
struct pcpu_format_pool *pbuf;
int cpu;
obj = alloc_percpu(struct pcpu_format_pool);
if (!obj)
return -ENOMEM;
for_each_possible_cpu(cpu) {
pbuf = per_cpu_ptr(obj, cpu);
memset(pbuf, 0, sizeof(*pbuf));
}
debug_format_pool = obj;
return 0;
}
EXPORT_SYMBOL(debug_format_buffer_alloc_buffers);
void debug_format_buffer_free_buffers(void)
{
struct pcpu_format_pool __percpu *tmp = debug_format_pool;
struct pcpu_format_pool *pbuf;
int cpu;
int i;
if (!debug_format_pool)
return;
debug_format_pool = NULL;
synchronize_rcu();
for_each_possible_cpu(cpu) {
pbuf = per_cpu_ptr(tmp, cpu);
for (i = 0; i < ARRAY_SIZE(pbuf->pf_dfb); i++)
set_bit(PF_INUSE, &pbuf->pf_dfb[i].dfb_flags);
}
free_percpu(tmp);
}
EXPORT_SYMBOL(debug_format_buffer_free_buffers);
bool libcfs_debug_raw_pointers;
bool get_debug_raw_pointers(void)
{
return libcfs_debug_raw_pointers;
}
EXPORT_SYMBOL(get_debug_raw_pointers);
void set_debug_raw_pointers(bool value)
{
libcfs_debug_raw_pointers = value;
}
EXPORT_SYMBOL(set_debug_raw_pointers);
#ifndef raw_cpu_ptr
#define raw_cpu_ptr(p) this_cpu_ptr(p)
#endif
static struct debug_format_buffer *debug_format_buffer_get_locked(void)
{
struct debug_format_buffer *dfb = NULL;
struct pcpu_format_pool *pbuf;
int i;
if (!debug_format_pool)
return NULL;
pbuf = raw_cpu_ptr(debug_format_pool);
for (i = 0; i < ARRAY_SIZE(pbuf->pf_dfb); i++) {
if (!test_and_set_bit(PF_INUSE, &pbuf->pf_dfb[i].dfb_flags)) {
dfb = &pbuf->pf_dfb[i];
break;
}
}
return dfb;
}
static void debug_format_buffer_put_locked(struct debug_format_buffer *dfb)
{
if (!debug_format_pool || !dfb)
return;
clear_bit(PF_INUSE, &dfb->dfb_flags);
}
/* return number of %p to %px replacements or < 0 on error */
static bool rewrite_format(const char *fmt, size_t nfsz, char *new_fmt)
{
const char *p = fmt;
char *q = new_fmt;
int written = 0;
int unhashed = 0;
if (WARN_ON_ONCE(!fmt))
return 0;
p = fmt;
q = new_fmt;
while (*p) {
if (written + 2 >= nfsz)
return false;
*q++ = *p++;
written++;
/* Replace %p with %px */
if (p[-1] == '%') {
if (p[0] == '%') {
if (written + 2 >= nfsz)
return false;
*q++ = *p++;
written++;
} else if (p[0] == 'p' && !isalnum(p[1])) {
if (written + 3 >= nfsz)
return false;
*q++ = *p++;
*q++ = 'x';
written += 2;
unhashed++;
}
}
}
*q = '\0';
return unhashed > 0;
}
/*
* @fmt: caller provided format string
* @m: if non-null points to per-cpu object
*
* return result is format string to use, it will be either:
* fmt: when no changes need to be made to original format
* *m->dfb_buf: when percpu pre-allocated is sufficient to hold updated format
*/
static inline const char *debug_format(const char *fmt,
struct debug_format_buffer **m)
{
struct debug_format_buffer *dfb_fmt;
*m = NULL;
if (likely(!libcfs_debug_raw_pointers))
return fmt;
if (!strstr(fmt, "%p"))
return fmt;
/* try to rewrite format into buf */
dfb_fmt = debug_format_buffer_get_locked();
if (dfb_fmt) {
size_t len = sizeof(dfb_fmt->dfb_buf) - 1;
if (rewrite_format(fmt, len, dfb_fmt->dfb_buf)) {
*m = dfb_fmt;
return dfb_fmt->dfb_buf;
}
debug_format_buffer_put_locked(dfb_fmt);
}
return fmt;
}
void libcfs_debug_msg(struct libcfs_debug_msg_data *msgdata,
const char *format, ...)
{
struct cfs_trace_cpu_data *tcd = NULL;
struct ptldebug_header header = {0};
struct cfs_trace_page *tage;
/* string_buf is used only if tcd != NULL, and is always set then */
char *string_buf = NULL;
char *debug_buf;
int known_size;
int needed = 85; /* seeded with average message length */
int max_nob;
va_list ap;
int retry;
const char *file = msgdata->msg_file;
const char *fn = msgdata->msg_fn;
struct cfs_debug_limit_state *cdls = msgdata->msg_cdls;
struct debug_format_buffer *dfb = NULL;
format = debug_format(format, &dfb);
if (strchr(file, '/'))
file = strrchr(file, '/') + 1;
tcd = cfs_trace_get_tcd();
/* cfs_trace_get_tcd() grabs a lock, which disables preemption and
* pins us to a particular CPU. This avoids an smp_processor_id()
* warning on Linux when debugging is enabled.
*/
cfs_set_ptldebug_header(&header, msgdata);
if (!tcd) /* arch may not log in IRQ context */
goto console;
if (tcd->tcd_cur_pages == 0)
header.ph_flags |= PH_FLAG_FIRST_RECORD;
if (tcd->tcd_shutting_down) {
cfs_trace_put_tcd(tcd);
tcd = NULL;
goto console;
}
known_size = strlen(file) + 1;
if (fn)
known_size += strlen(fn) + 1;
if (libcfs_debug_binary)
known_size += sizeof(header);
/*
* May perform an additional pass to update 'needed' and increase
* tage buffer size to match vsnprintf reported size required
* On the second pass (retry=1) use vscnprintf [which returns
* number of bytes written not including the terminating nul]
* to clarify `needed` is used as number of bytes written
* for the remainder of this function
*/
for (retry = 0; retry < 2; retry++) {
tage = cfs_trace_get_tage(tcd, needed + known_size + 1);
if (!tage) {
if (needed + known_size > PAGE_SIZE)
header.ph_mask |= D_ERROR;
cfs_trace_put_tcd(tcd);
tcd = NULL;
goto console;
}
string_buf = (char *)page_address(tage->page) +
tage->used + known_size;
max_nob = PAGE_SIZE - tage->used - known_size;
if (max_nob <= 0) {
pr_emerg("LustreError: negative max_nob: %d\n",
max_nob);
header.ph_mask |= D_ERROR;
cfs_trace_put_tcd(tcd);
tcd = NULL;
goto console;
}
va_start(ap, format);
if (retry)
needed = vscnprintf(string_buf, max_nob, format, ap);
else
needed = vsnprintf(string_buf, max_nob, format, ap);
va_end(ap);
if (needed < max_nob) /* well. printing ok.. */
break;
}
/* `needed` is actual bytes written to string_buf */
if (unlikely(*(string_buf + needed - 1) != '\n')) {
pr_info("Lustre: format at %s:%d:%s doesn't end in newline\n",
file, header.ph_line_num, fn);
}
header.ph_len = known_size + needed;
debug_buf = (char *)page_address(tage->page) + tage->used;
if (libcfs_debug_binary) {
memcpy(debug_buf, &header, sizeof(header));
tage->used += sizeof(header);
debug_buf += sizeof(header);
}
snprintf(debug_buf, PAGE_SIZE - tage->used, "%s", file);
tage->used += strlen(file) + 1;
debug_buf += strlen(file) + 1;
if (fn) {
snprintf(debug_buf, PAGE_SIZE - tage->used, "%s", fn);
tage->used += strlen(fn) + 1;
debug_buf += strlen(fn) + 1;
}
__LASSERT(debug_buf == string_buf);
tage->used += needed;
__LASSERT(tage->used <= PAGE_SIZE);
console:
if ((header.ph_mask & libcfs_printk) == 0 &&
(header.ph_subsys & libcfs_subsystem_printk) == 0) {
/* no console output requested */
if (tcd != NULL)
cfs_trace_put_tcd(tcd);
goto out;
}
if (cdls != NULL) {
/* avoid unlikely case of many errors between printing */
if (unlikely(cdls->cdls_count < 0 &&
cdls->cdls_count >= -600)) {
cdls->cdls_next = jiffies +
cfs_time_seconds(-cdls->cdls_count);
cdls->cdls_count = 1;
}
if (libcfs_console_ratelimit &&
cdls->cdls_next != 0 && /* not first time ever */
time_before(jiffies, cdls->cdls_next)) {
/* skipping a console message */
cdls->cdls_count++;
if (tcd != NULL)
cfs_trace_put_tcd(tcd);
goto out;
}
if (time_after(jiffies, cdls->cdls_next +
libcfs_console_max_delay +
cfs_time_seconds(10))) {
/* last timeout was a long time ago */
cdls->cdls_delay /= libcfs_console_backoff * 4;
} else {
cdls->cdls_delay *= libcfs_console_backoff;
}
if (cdls->cdls_delay < libcfs_console_min_delay)
cdls->cdls_delay = libcfs_console_min_delay;
else if (cdls->cdls_delay > libcfs_console_max_delay)
cdls->cdls_delay = libcfs_console_max_delay;
/* ensure cdls_next is never zero after it's been seen */
cdls->cdls_next = (jiffies + cdls->cdls_delay) | 1;
}
if (tcd) {
cfs_print_to_console(&header, file, fn, "%s", string_buf);
cfs_trace_put_tcd(tcd);
} else {
struct va_format vaf;
va_start(ap, format);
vaf.fmt = format;
vaf.va = ≈
cfs_vprint_to_console(&header, &vaf, file, fn);
va_end(ap);
}
if (cdls != NULL && cdls->cdls_count != 0) {
cfs_print_to_console(&header, file, fn,
"Skipped %d previous similar message%s\n",
cdls->cdls_count,
cdls->cdls_count > 1 ? "s" : "");
cdls->cdls_count = 0;
}
out:
debug_format_buffer_put_locked(dfb);
}
EXPORT_SYMBOL(libcfs_debug_msg);
void
cfs_trace_assertion_failed(const char *str,
struct libcfs_debug_msg_data *msgdata)
{
struct ptldebug_header hdr;
libcfs_panic_in_progress = 1;
libcfs_catastrophe = 1;
smp_mb();
cfs_set_ptldebug_header(&hdr, msgdata);
hdr.ph_mask = D_EMERG;
cfs_print_to_console(&hdr, msgdata->msg_file, msgdata->msg_fn,
"%s", str);
panic("Lustre debug assertion failure\n");
/* not reached */
}
static void
panic_collect_pages(struct page_collection *pc)
{
/* Do the collect_pages job on a single CPU: assumes that all other
* CPUs have been stopped during a panic. If this isn't true for some
* arch, this will have to be implemented separately in each arch. */
int i;
int j;
struct cfs_trace_cpu_data *tcd;
INIT_LIST_HEAD(&pc->pc_pages);
cfs_tcd_for_each(tcd, i, j) {
list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
tcd->tcd_cur_pages = 0;
}
}
static void collect_pages_on_all_cpus(struct page_collection *pc)
{
struct cfs_trace_cpu_data *tcd;
int i, cpu;
for_each_possible_cpu(cpu) {
cfs_tcd_for_each_type_lock(tcd, i, cpu) {
list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
tcd->tcd_cur_pages = 0;
}
}
}
static void collect_pages(struct page_collection *pc)
{
INIT_LIST_HEAD(&pc->pc_pages);
if (libcfs_panic_in_progress)
panic_collect_pages(pc);
else
collect_pages_on_all_cpus(pc);
}
static void put_pages_back_on_all_cpus(struct page_collection *pc)
{
struct cfs_trace_cpu_data *tcd;
struct list_head *cur_head;
struct cfs_trace_page *tage;
struct cfs_trace_page *tmp;
int i, cpu;
for_each_possible_cpu(cpu) {
cfs_tcd_for_each_type_lock(tcd, i, cpu) {
cur_head = tcd->tcd_pages.next;
list_for_each_entry_safe(tage, tmp, &pc->pc_pages,
linkage) {
__LASSERT_TAGE_INVARIANT(tage);
if (tage->cpu != cpu || tage->type != i)
continue;
cfs_tage_to_tail(tage, cur_head);
tcd->tcd_cur_pages++;
}
}
}
}
static void put_pages_back(struct page_collection *pc)
{
if (!libcfs_panic_in_progress)
put_pages_back_on_all_cpus(pc);
}
#ifdef LNET_DUMP_ON_PANIC
void cfs_trace_debug_print(void)
{
struct page_collection pc;
struct cfs_trace_page *tage;
struct cfs_trace_page *tmp;
struct page *page;
collect_pages(&pc);
list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
char *p, *file, *fn;
__LASSERT_TAGE_INVARIANT(tage);
page = tage->page;
p = page_address(page);
while (p < ((char *)page_address(page) + tage->used)) {
struct ptldebug_header *hdr;
int len;
hdr = (void *)p;
p += sizeof(*hdr);
file = p;
p += strlen(file) + 1;
fn = p;
p += strlen(fn) + 1;
len = hdr->ph_len - (int)(p - (char *)hdr);
cfs_print_to_console(hdr, file, fn, "%.*s", len, p);
p += len;
}
list_del(&tage->linkage);
cfs_tage_free(tage);
}
down_write(&cfs_tracefile_sem);
while ((page = list_first_entry_or_null(&daemon_pages,
struct page, lru)) != NULL) {
char *p, *file, *fn;
p = page_address(page);
while (p < ((char *)page_address(page) + page->private)) {
struct ptldebug_header *hdr;
int len;
hdr = (void *)p;
p += sizeof(*hdr);
file = p;
p += strlen(file) + 1;
fn = p;
p += strlen(fn) + 1;
len = hdr->ph_len - (int)(p - (char *)hdr);
cfs_print_to_console(hdr, file, fn, "%.*s", len, p);
p += len;
}
list_del_init(&page->lru);
daemon_pages_count -= 1;
put_page(page);
}
up_write(&cfs_tracefile_sem);
}
#endif /* LNET_DUMP_ON_PANIC */
int cfs_tracefile_dump_all_pages(char *filename)
{
struct page_collection pc;
struct file *filp;
struct cfs_trace_page *tage;
struct cfs_trace_page *tmp;
char *buf;
struct page *page;
int rc;
down_write(&cfs_tracefile_sem);
filp = filp_open(filename, O_CREAT|O_EXCL|O_WRONLY|O_LARGEFILE, 0600);
if (IS_ERR(filp)) {
rc = PTR_ERR(filp);
filp = NULL;
pr_err("LustreError: can't open %s for dump: rc = %d\n",
filename, rc);
goto out;
}
collect_pages(&pc);
if (list_empty(&pc.pc_pages)) {
rc = 0;
goto close;
}
/* ok, for now, just write the pages. in the future we'll be building
* iobufs with the pages and calling generic_direct_IO */
list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
__LASSERT_TAGE_INVARIANT(tage);
buf = kmap(tage->page);
rc = kernel_write(filp, buf, tage->used, &filp->f_pos);
kunmap(tage->page);
if (rc != (int)tage->used) {
pr_warn("Lustre: wanted to write %u but wrote %d\n",
tage->used, rc);
put_pages_back(&pc);
__LASSERT(list_empty(&pc.pc_pages));
break;
}
list_del(&tage->linkage);
cfs_tage_free(tage);
}
while ((page = list_first_entry_or_null(&daemon_pages,
struct page, lru)) != NULL) {
buf = page_address(page);
rc = kernel_write(filp, buf, page->private, &filp->f_pos);
if (rc != (int)page->private) {
pr_warn("Lustre: wanted to write %u but wrote %d\n",
(int)page->private, rc);
break;
}
list_del(&page->lru);
daemon_pages_count -= 1;
put_page(page);
}
rc = vfs_fsync_range(filp, 0, LLONG_MAX, 1);
if (rc)
pr_err("LustreError: sync returns: rc = %d\n", rc);
close:
filp_close(filp, NULL);
out:
up_write(&cfs_tracefile_sem);
return rc;
}
void cfs_trace_flush_pages(void)
{
struct page_collection pc;
struct cfs_trace_page *tage;
struct page *page;
collect_pages(&pc);
while (!list_empty(&pc.pc_pages)) {
tage = list_first_entry(&pc.pc_pages,
struct cfs_trace_page, linkage);
__LASSERT_TAGE_INVARIANT(tage);
list_del(&tage->linkage);
cfs_tage_free(tage);
}
down_write(&cfs_tracefile_sem);
while ((page = list_first_entry_or_null(&daemon_pages,
struct page, lru)) != NULL) {
list_del(&page->lru);
daemon_pages_count -= 1;
put_page(page);
}
up_write(&cfs_tracefile_sem);
}
int cfs_trace_copyout_string(char __user *usr_buffer, int usr_buffer_nob,
const char *knl_buffer, char *append)
{
/* NB if 'append' != NULL, it's a single character to append to the
* copied out string - usually "\n", for /proc entries and "" (i.e. a
* terminating zero byte) for sysctl entries */
int nob = strlen(knl_buffer);
if (nob > usr_buffer_nob)
nob = usr_buffer_nob;
if (copy_to_user(usr_buffer, knl_buffer, nob))
return -EFAULT;
if (append != NULL && nob < usr_buffer_nob) {
if (copy_to_user(usr_buffer + nob, append, 1))
return -EFAULT;
nob++;
}
return nob;
}
EXPORT_SYMBOL(cfs_trace_copyout_string);
int cfs_trace_dump_debug_buffer_usrstr(void __user *usr_str, int usr_str_nob)
{
char *str;
char *path;
int rc;
if (usr_str_nob > PATH_MAX)
return -E2BIG;
str = memdup_user_nul(usr_str, usr_str_nob);
if (IS_ERR(str))
return PTR_ERR(str);
path = strim(str);
if (path[0] != '/')
rc = -EINVAL;
else
rc = cfs_tracefile_dump_all_pages(path);
kfree(str);
return rc;
}
int cfs_trace_daemon_command(char *str)
{
int rc = 0;
down_write(&cfs_tracefile_sem);
if (strcmp(str, "stop") == 0) {
up_write(&cfs_tracefile_sem);
cfs_trace_stop_thread();
down_write(&cfs_tracefile_sem);
memset(cfs_tracefile, 0, sizeof(cfs_tracefile));
} else if (strncmp(str, "size=", 5) == 0) {
unsigned long tmp;
rc = kstrtoul(str + 5, 10, &tmp);
if (!rc) {
if (tmp < 10 || tmp > 20480)
cfs_tracefile_size = CFS_TRACEFILE_SIZE;
else
cfs_tracefile_size = tmp << 20;
}
} else if (strlen(str) >= sizeof(cfs_tracefile)) {
rc = -ENAMETOOLONG;
} else if (str[0] != '/') {
rc = -EINVAL;
} else {
strcpy(cfs_tracefile, str);
pr_info("Lustre: debug daemon will attempt to start writing to %s (%lukB max)\n",
cfs_tracefile, (long)(cfs_tracefile_size >> 10));
cfs_trace_start_thread();
}
up_write(&cfs_tracefile_sem);
return rc;
}
int cfs_trace_daemon_command_usrstr(void __user *usr_str, int usr_str_nob)
{
char *str;
int rc;
if (usr_str_nob > USHRT_MAX)
return -E2BIG;
str = memdup_user_nul(usr_str, usr_str_nob);
if (IS_ERR(str))
return PTR_ERR(str);
rc = cfs_trace_daemon_command(strim(str));
kfree(str);
return rc;
}
int cfs_trace_set_debug_mb(int mb)
{
int i;
int j;
unsigned long pages;
unsigned long total_mb = (compat_totalram_pages() >> (20 - PAGE_SHIFT));
unsigned long limit = max_t(unsigned long, 512, (total_mb * 4) / 5);
struct cfs_trace_cpu_data *tcd;
if (mb < num_possible_cpus()) {
pr_warn("Lustre: %d MB is too small for debug buffer size, setting it to %d MB.\n",
mb, num_possible_cpus());
mb = num_possible_cpus();
}
if (mb > limit) {
pr_warn("Lustre: %d MB is too large for debug buffer size, setting it to %lu MB.\n",
mb, limit);
mb = limit;
}
mb /= num_possible_cpus();
pages = mb << (20 - PAGE_SHIFT);
down_write(&cfs_tracefile_sem);
cfs_tcd_for_each(tcd, i, j)
tcd->tcd_max_pages = (pages * tcd->tcd_pages_factor) / 100;
daemon_pages_max = pages;
up_write(&cfs_tracefile_sem);
return mb;
}
int cfs_trace_get_debug_mb(void)
{
int i;
int j;
struct cfs_trace_cpu_data *tcd;
int total_pages = 0;
down_read(&cfs_tracefile_sem);
cfs_tcd_for_each(tcd, i, j)
total_pages += tcd->tcd_max_pages;
up_read(&cfs_tracefile_sem);
if (total_pages)
return (total_pages >> (20 - PAGE_SHIFT)) + 1;
else
return 0;
}
static int tracefiled(void *arg)
{
struct page_collection pc;
struct cfs_trace_page *tage;
struct cfs_trace_page *tmp;
struct file *filp;
char *buf;
int last_loop = 0;
int rc;
while (!last_loop) {
LIST_HEAD(for_daemon_pages);
int for_daemon_pages_count = 0;
schedule_timeout_interruptible(cfs_time_seconds(1));
if (kthread_should_stop())
last_loop = 1;
collect_pages(&pc);
if (list_empty(&pc.pc_pages))
continue;
filp = NULL;
down_read(&cfs_tracefile_sem);
if (cfs_tracefile[0] != 0) {
filp = filp_open(cfs_tracefile,
O_CREAT | O_RDWR | O_LARGEFILE,
0600);
if (IS_ERR(filp)) {
rc = PTR_ERR(filp);
filp = NULL;
pr_warn("Lustre: couldn't open %s: rc = %d\n",
cfs_tracefile, rc);
}
}
up_read(&cfs_tracefile_sem);
list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
__LASSERT_TAGE_INVARIANT(tage);
if (filp) {
struct dentry *de = file_dentry(filp);
static loff_t f_pos;
if (f_pos >= (off_t)cfs_tracefile_size)
f_pos = 0;
else if (f_pos > i_size_read(de->d_inode))
f_pos = i_size_read(de->d_inode);
buf = kmap(tage->page);
rc = kernel_write(filp, buf, tage->used,
&f_pos);
kunmap(tage->page);
if (rc != (int)tage->used) {
pr_warn("Lustre: wanted to write %u but wrote %d\n",
tage->used, rc);
put_pages_back(&pc);
__LASSERT(list_empty(&pc.pc_pages));
break;
}
}
list_del_init(&tage->linkage);
list_add_tail(&tage->page->lru, &for_daemon_pages);
for_daemon_pages_count += 1;
tage->page->private = (int)tage->used;
kfree(tage);
atomic_dec(&cfs_tage_allocated);
}
if (filp)
filp_close(filp, NULL);
down_write(&cfs_tracefile_sem);
list_splice_tail(&for_daemon_pages, &daemon_pages);
daemon_pages_count += for_daemon_pages_count;
while (daemon_pages_count > daemon_pages_max) {
struct page *p = list_first_entry(&daemon_pages,
struct page, lru);
list_del(&p->lru);
put_page(p);
daemon_pages_count -= 1;
}
up_write(&cfs_tracefile_sem);
if (!list_empty(&pc.pc_pages)) {
int i;
pr_alert("Lustre: trace pages aren't empty\n");
pr_err("Lustre: total cpus(%d): ", num_possible_cpus());
for (i = 0; i < num_possible_cpus(); i++)
if (cpu_online(i))
pr_cont("%d(on) ", i);
else
pr_cont("%d(off) ", i);
pr_cont("\n");
i = 0;
list_for_each_entry_safe(tage, tmp, &pc.pc_pages,
linkage)
pr_err("Lustre: page %d belongs to cpu %d\n",
++i, tage->cpu);
pr_err("Lustre: There are %d pages unwritten\n", i);
}
__LASSERT(list_empty(&pc.pc_pages));
}
return 0;
}
int cfs_trace_start_thread(void)
{
struct task_struct *tsk;
int rc = 0;
if (tctl_task)
return 0;
tsk = kthread_create(tracefiled, NULL, "ktracefiled");
if (IS_ERR(tsk))
rc = -ECHILD;
else if (cmpxchg(&tctl_task, NULL, tsk) != NULL)
/* already running */
kthread_stop(tsk);
else
wake_up_process(tsk);
return rc;
}
void cfs_trace_stop_thread(void)
{
struct task_struct *tsk;
tsk = xchg(&tctl_task, NULL);
if (tsk) {
pr_info("Lustre: shutting down debug daemon thread...\n");
kthread_stop(tsk);
}
}
/* percents to share the total debug memory for each type */
static unsigned int pages_factor[CFS_TCD_TYPE_CNT] = {
80, /* 80% pages for CFS_TCD_TYPE_PROC */
10, /* 10% pages for CFS_TCD_TYPE_SOFTIRQ */
10 /* 10% pages for CFS_TCD_TYPE_IRQ */
};
int cfs_tracefile_init(int max_pages)
{
struct cfs_trace_cpu_data *tcd;
int i;
int j;
/* initialize trace_data */
memset(cfs_trace_data, 0, sizeof(cfs_trace_data));
for (i = 0; i < CFS_TCD_TYPE_CNT; i++) {
cfs_trace_data[i] =
kmalloc_array(num_possible_cpus(),
sizeof(union cfs_trace_data_union),
GFP_KERNEL);
if (!cfs_trace_data[i])
goto out_trace_data;
}
/* arch related info initialized */
cfs_tcd_for_each(tcd, i, j) {
int factor = pages_factor[i];
/* Note that we have three separate spin_lock_init()
* calls so that the locks get three separate classes
* and lockdep never thinks they are related. As they
* are used in different interrupt contexts, lockdep
* would otherwise think that the usage would conflict.
*/
switch(i) {
case CFS_TCD_TYPE_PROC:
spin_lock_init(&tcd->tcd_lock);
break;
case CFS_TCD_TYPE_SOFTIRQ:
spin_lock_init(&tcd->tcd_lock);
break;
case CFS_TCD_TYPE_IRQ:
spin_lock_init(&tcd->tcd_lock);
break;
}
tcd->tcd_pages_factor = factor;
tcd->tcd_type = i;
tcd->tcd_cpu = j;
INIT_LIST_HEAD(&tcd->tcd_pages);
INIT_LIST_HEAD(&tcd->tcd_stock_pages);
tcd->tcd_cur_pages = 0;
tcd->tcd_cur_stock_pages = 0;
tcd->tcd_max_pages = (max_pages * factor) / 100;
LASSERT(tcd->tcd_max_pages > 0);
tcd->tcd_shutting_down = 0;
}
daemon_pages_max = max_pages;
return 0;
out_trace_data:
for (i = 0; cfs_trace_data[i]; i++) {
kfree(cfs_trace_data[i]);
cfs_trace_data[i] = NULL;
}
pr_err("lnet: Not enough memory\n");
return -ENOMEM;
}
static void trace_cleanup_on_all_cpus(void)
{
struct cfs_trace_cpu_data *tcd;
struct cfs_trace_page *tage;
int i, cpu;
for_each_possible_cpu(cpu) {
cfs_tcd_for_each_type_lock(tcd, i, cpu) {
if (!tcd->tcd_pages_factor)
/* Not initialised */
continue;
tcd->tcd_shutting_down = 1;
while (!list_empty(&tcd->tcd_pages)) {
tage = list_first_entry(&tcd->tcd_pages,
struct cfs_trace_page,
linkage);
__LASSERT_TAGE_INVARIANT(tage);
list_del(&tage->linkage);
cfs_tage_free(tage);
}
tcd->tcd_cur_pages = 0;
}
}
}
static void cfs_trace_cleanup(void)
{
struct page_collection pc;
int i;
INIT_LIST_HEAD(&pc.pc_pages);
trace_cleanup_on_all_cpus();
for (i = 0; i < CFS_TCD_TYPE_CNT && cfs_trace_data[i]; i++) {
kfree(cfs_trace_data[i]);
cfs_trace_data[i] = NULL;
}
}
void cfs_tracefile_exit(void)
{
cfs_trace_stop_thread();
cfs_trace_flush_pages();
cfs_trace_cleanup();
}
