linux/fs/dlm/debug_fs.c
David Teigland 573c24c4af dlm: always use GFP_NOFS
Replace all GFP_KERNEL and ls_allocation with GFP_NOFS.
ls_allocation would be GFP_KERNEL for userland lockspaces
and GFP_NOFS for file system lockspaces.

It was discovered that any lockspaces on the system can
affect all others by triggering memory reclaim in the
file system which could in turn call back into the dlm
to acquire locks, deadlocking dlm threads that were
shared by all lockspaces, like dlm_recv.

Signed-off-by: David Teigland <teigland@redhat.com>
2009-11-30 16:34:43 -06:00

729 lines
16 KiB
C

/******************************************************************************
*******************************************************************************
**
** Copyright (C) 2005-2009 Red Hat, Inc. All rights reserved.
**
** This copyrighted material is made available to anyone wishing to use,
** modify, copy, or redistribute it subject to the terms and conditions
** of the GNU General Public License v.2.
**
*******************************************************************************
******************************************************************************/
#include <linux/pagemap.h>
#include <linux/seq_file.h>
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/debugfs.h>
#include "dlm_internal.h"
#include "lock.h"
#define DLM_DEBUG_BUF_LEN 4096
static char debug_buf[DLM_DEBUG_BUF_LEN];
static struct mutex debug_buf_lock;
static struct dentry *dlm_root;
static char *print_lockmode(int mode)
{
switch (mode) {
case DLM_LOCK_IV:
return "--";
case DLM_LOCK_NL:
return "NL";
case DLM_LOCK_CR:
return "CR";
case DLM_LOCK_CW:
return "CW";
case DLM_LOCK_PR:
return "PR";
case DLM_LOCK_PW:
return "PW";
case DLM_LOCK_EX:
return "EX";
default:
return "??";
}
}
static int print_format1_lock(struct seq_file *s, struct dlm_lkb *lkb,
struct dlm_rsb *res)
{
seq_printf(s, "%08x %s", lkb->lkb_id, print_lockmode(lkb->lkb_grmode));
if (lkb->lkb_status == DLM_LKSTS_CONVERT ||
lkb->lkb_status == DLM_LKSTS_WAITING)
seq_printf(s, " (%s)", print_lockmode(lkb->lkb_rqmode));
if (lkb->lkb_nodeid) {
if (lkb->lkb_nodeid != res->res_nodeid)
seq_printf(s, " Remote: %3d %08x", lkb->lkb_nodeid,
lkb->lkb_remid);
else
seq_printf(s, " Master: %08x", lkb->lkb_remid);
}
if (lkb->lkb_wait_type)
seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
return seq_printf(s, "\n");
}
static int print_format1(struct dlm_rsb *res, struct seq_file *s)
{
struct dlm_lkb *lkb;
int i, lvblen = res->res_ls->ls_lvblen, recover_list, root_list;
int rv;
lock_rsb(res);
rv = seq_printf(s, "\nResource %p Name (len=%d) \"",
res, res->res_length);
if (rv)
goto out;
for (i = 0; i < res->res_length; i++) {
if (isprint(res->res_name[i]))
seq_printf(s, "%c", res->res_name[i]);
else
seq_printf(s, "%c", '.');
}
if (res->res_nodeid > 0)
rv = seq_printf(s, "\" \nLocal Copy, Master is node %d\n",
res->res_nodeid);
else if (res->res_nodeid == 0)
rv = seq_printf(s, "\" \nMaster Copy\n");
else if (res->res_nodeid == -1)
rv = seq_printf(s, "\" \nLooking up master (lkid %x)\n",
res->res_first_lkid);
else
rv = seq_printf(s, "\" \nInvalid master %d\n",
res->res_nodeid);
if (rv)
goto out;
/* Print the LVB: */
if (res->res_lvbptr) {
seq_printf(s, "LVB: ");
for (i = 0; i < lvblen; i++) {
if (i == lvblen / 2)
seq_printf(s, "\n ");
seq_printf(s, "%02x ",
(unsigned char) res->res_lvbptr[i]);
}
if (rsb_flag(res, RSB_VALNOTVALID))
seq_printf(s, " (INVALID)");
rv = seq_printf(s, "\n");
if (rv)
goto out;
}
root_list = !list_empty(&res->res_root_list);
recover_list = !list_empty(&res->res_recover_list);
if (root_list || recover_list) {
rv = seq_printf(s, "Recovery: root %d recover %d flags %lx "
"count %d\n", root_list, recover_list,
res->res_flags, res->res_recover_locks_count);
if (rv)
goto out;
}
/* Print the locks attached to this resource */
seq_printf(s, "Granted Queue\n");
list_for_each_entry(lkb, &res->res_grantqueue, lkb_statequeue) {
rv = print_format1_lock(s, lkb, res);
if (rv)
goto out;
}
seq_printf(s, "Conversion Queue\n");
list_for_each_entry(lkb, &res->res_convertqueue, lkb_statequeue) {
rv = print_format1_lock(s, lkb, res);
if (rv)
goto out;
}
seq_printf(s, "Waiting Queue\n");
list_for_each_entry(lkb, &res->res_waitqueue, lkb_statequeue) {
rv = print_format1_lock(s, lkb, res);
if (rv)
goto out;
}
if (list_empty(&res->res_lookup))
goto out;
seq_printf(s, "Lookup Queue\n");
list_for_each_entry(lkb, &res->res_lookup, lkb_rsb_lookup) {
rv = seq_printf(s, "%08x %s", lkb->lkb_id,
print_lockmode(lkb->lkb_rqmode));
if (lkb->lkb_wait_type)
seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
rv = seq_printf(s, "\n");
}
out:
unlock_rsb(res);
return rv;
}
static int print_format2_lock(struct seq_file *s, struct dlm_lkb *lkb,
struct dlm_rsb *r)
{
u64 xid = 0;
u64 us;
int rv;
if (lkb->lkb_flags & DLM_IFL_USER) {
if (lkb->lkb_ua)
xid = lkb->lkb_ua->xid;
}
/* microseconds since lkb was added to current queue */
us = ktime_to_us(ktime_sub(ktime_get(), lkb->lkb_timestamp));
/* id nodeid remid pid xid exflags flags sts grmode rqmode time_us
r_nodeid r_len r_name */
rv = seq_printf(s, "%x %d %x %u %llu %x %x %d %d %d %llu %u %d \"%s\"\n",
lkb->lkb_id,
lkb->lkb_nodeid,
lkb->lkb_remid,
lkb->lkb_ownpid,
(unsigned long long)xid,
lkb->lkb_exflags,
lkb->lkb_flags,
lkb->lkb_status,
lkb->lkb_grmode,
lkb->lkb_rqmode,
(unsigned long long)us,
r->res_nodeid,
r->res_length,
r->res_name);
return rv;
}
static int print_format2(struct dlm_rsb *r, struct seq_file *s)
{
struct dlm_lkb *lkb;
int rv = 0;
lock_rsb(r);
list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue) {
rv = print_format2_lock(s, lkb, r);
if (rv)
goto out;
}
list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue) {
rv = print_format2_lock(s, lkb, r);
if (rv)
goto out;
}
list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue) {
rv = print_format2_lock(s, lkb, r);
if (rv)
goto out;
}
out:
unlock_rsb(r);
return rv;
}
static int print_format3_lock(struct seq_file *s, struct dlm_lkb *lkb,
int rsb_lookup)
{
u64 xid = 0;
int rv;
if (lkb->lkb_flags & DLM_IFL_USER) {
if (lkb->lkb_ua)
xid = lkb->lkb_ua->xid;
}
rv = seq_printf(s, "lkb %x %d %x %u %llu %x %x %d %d %d %d %d %d %u %llu %llu\n",
lkb->lkb_id,
lkb->lkb_nodeid,
lkb->lkb_remid,
lkb->lkb_ownpid,
(unsigned long long)xid,
lkb->lkb_exflags,
lkb->lkb_flags,
lkb->lkb_status,
lkb->lkb_grmode,
lkb->lkb_rqmode,
lkb->lkb_highbast,
rsb_lookup,
lkb->lkb_wait_type,
lkb->lkb_lvbseq,
(unsigned long long)ktime_to_ns(lkb->lkb_timestamp),
(unsigned long long)ktime_to_ns(lkb->lkb_time_bast));
return rv;
}
static int print_format3(struct dlm_rsb *r, struct seq_file *s)
{
struct dlm_lkb *lkb;
int i, lvblen = r->res_ls->ls_lvblen;
int print_name = 1;
int rv;
lock_rsb(r);
rv = seq_printf(s, "rsb %p %d %x %lx %d %d %u %d ",
r,
r->res_nodeid,
r->res_first_lkid,
r->res_flags,
!list_empty(&r->res_root_list),
!list_empty(&r->res_recover_list),
r->res_recover_locks_count,
r->res_length);
if (rv)
goto out;
for (i = 0; i < r->res_length; i++) {
if (!isascii(r->res_name[i]) || !isprint(r->res_name[i]))
print_name = 0;
}
seq_printf(s, "%s", print_name ? "str " : "hex");
for (i = 0; i < r->res_length; i++) {
if (print_name)
seq_printf(s, "%c", r->res_name[i]);
else
seq_printf(s, " %02x", (unsigned char)r->res_name[i]);
}
rv = seq_printf(s, "\n");
if (rv)
goto out;
if (!r->res_lvbptr)
goto do_locks;
seq_printf(s, "lvb %u %d", r->res_lvbseq, lvblen);
for (i = 0; i < lvblen; i++)
seq_printf(s, " %02x", (unsigned char)r->res_lvbptr[i]);
rv = seq_printf(s, "\n");
if (rv)
goto out;
do_locks:
list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue) {
rv = print_format3_lock(s, lkb, 0);
if (rv)
goto out;
}
list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue) {
rv = print_format3_lock(s, lkb, 0);
if (rv)
goto out;
}
list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue) {
rv = print_format3_lock(s, lkb, 0);
if (rv)
goto out;
}
list_for_each_entry(lkb, &r->res_lookup, lkb_rsb_lookup) {
rv = print_format3_lock(s, lkb, 1);
if (rv)
goto out;
}
out:
unlock_rsb(r);
return rv;
}
struct rsbtbl_iter {
struct dlm_rsb *rsb;
unsigned bucket;
int format;
int header;
};
/* seq_printf returns -1 if the buffer is full, and 0 otherwise.
If the buffer is full, seq_printf can be called again, but it
does nothing and just returns -1. So, the these printing routines
periodically check the return value to avoid wasting too much time
trying to print to a full buffer. */
static int table_seq_show(struct seq_file *seq, void *iter_ptr)
{
struct rsbtbl_iter *ri = iter_ptr;
int rv = 0;
switch (ri->format) {
case 1:
rv = print_format1(ri->rsb, seq);
break;
case 2:
if (ri->header) {
seq_printf(seq, "id nodeid remid pid xid exflags "
"flags sts grmode rqmode time_ms "
"r_nodeid r_len r_name\n");
ri->header = 0;
}
rv = print_format2(ri->rsb, seq);
break;
case 3:
if (ri->header) {
seq_printf(seq, "version rsb 1.1 lvb 1.1 lkb 1.1\n");
ri->header = 0;
}
rv = print_format3(ri->rsb, seq);
break;
}
return rv;
}
static const struct seq_operations format1_seq_ops;
static const struct seq_operations format2_seq_ops;
static const struct seq_operations format3_seq_ops;
static void *table_seq_start(struct seq_file *seq, loff_t *pos)
{
struct dlm_ls *ls = seq->private;
struct rsbtbl_iter *ri;
struct dlm_rsb *r;
loff_t n = *pos;
unsigned bucket, entry;
bucket = n >> 32;
entry = n & ((1LL << 32) - 1);
if (bucket >= ls->ls_rsbtbl_size)
return NULL;
ri = kzalloc(sizeof(struct rsbtbl_iter), GFP_NOFS);
if (!ri)
return NULL;
if (n == 0)
ri->header = 1;
if (seq->op == &format1_seq_ops)
ri->format = 1;
if (seq->op == &format2_seq_ops)
ri->format = 2;
if (seq->op == &format3_seq_ops)
ri->format = 3;
spin_lock(&ls->ls_rsbtbl[bucket].lock);
if (!list_empty(&ls->ls_rsbtbl[bucket].list)) {
list_for_each_entry(r, &ls->ls_rsbtbl[bucket].list,
res_hashchain) {
if (!entry--) {
dlm_hold_rsb(r);
ri->rsb = r;
ri->bucket = bucket;
spin_unlock(&ls->ls_rsbtbl[bucket].lock);
return ri;
}
}
}
spin_unlock(&ls->ls_rsbtbl[bucket].lock);
/*
* move to the first rsb in the next non-empty bucket
*/
/* zero the entry */
n &= ~((1LL << 32) - 1);
while (1) {
bucket++;
n += 1LL << 32;
if (bucket >= ls->ls_rsbtbl_size) {
kfree(ri);
return NULL;
}
spin_lock(&ls->ls_rsbtbl[bucket].lock);
if (!list_empty(&ls->ls_rsbtbl[bucket].list)) {
r = list_first_entry(&ls->ls_rsbtbl[bucket].list,
struct dlm_rsb, res_hashchain);
dlm_hold_rsb(r);
ri->rsb = r;
ri->bucket = bucket;
spin_unlock(&ls->ls_rsbtbl[bucket].lock);
*pos = n;
return ri;
}
spin_unlock(&ls->ls_rsbtbl[bucket].lock);
}
}
static void *table_seq_next(struct seq_file *seq, void *iter_ptr, loff_t *pos)
{
struct dlm_ls *ls = seq->private;
struct rsbtbl_iter *ri = iter_ptr;
struct list_head *next;
struct dlm_rsb *r, *rp;
loff_t n = *pos;
unsigned bucket;
bucket = n >> 32;
/*
* move to the next rsb in the same bucket
*/
spin_lock(&ls->ls_rsbtbl[bucket].lock);
rp = ri->rsb;
next = rp->res_hashchain.next;
if (next != &ls->ls_rsbtbl[bucket].list) {
r = list_entry(next, struct dlm_rsb, res_hashchain);
dlm_hold_rsb(r);
ri->rsb = r;
spin_unlock(&ls->ls_rsbtbl[bucket].lock);
dlm_put_rsb(rp);
++*pos;
return ri;
}
spin_unlock(&ls->ls_rsbtbl[bucket].lock);
dlm_put_rsb(rp);
/*
* move to the first rsb in the next non-empty bucket
*/
/* zero the entry */
n &= ~((1LL << 32) - 1);
while (1) {
bucket++;
n += 1LL << 32;
if (bucket >= ls->ls_rsbtbl_size) {
kfree(ri);
return NULL;
}
spin_lock(&ls->ls_rsbtbl[bucket].lock);
if (!list_empty(&ls->ls_rsbtbl[bucket].list)) {
r = list_first_entry(&ls->ls_rsbtbl[bucket].list,
struct dlm_rsb, res_hashchain);
dlm_hold_rsb(r);
ri->rsb = r;
ri->bucket = bucket;
spin_unlock(&ls->ls_rsbtbl[bucket].lock);
*pos = n;
return ri;
}
spin_unlock(&ls->ls_rsbtbl[bucket].lock);
}
}
static void table_seq_stop(struct seq_file *seq, void *iter_ptr)
{
struct rsbtbl_iter *ri = iter_ptr;
if (ri) {
dlm_put_rsb(ri->rsb);
kfree(ri);
}
}
static const struct seq_operations format1_seq_ops = {
.start = table_seq_start,
.next = table_seq_next,
.stop = table_seq_stop,
.show = table_seq_show,
};
static const struct seq_operations format2_seq_ops = {
.start = table_seq_start,
.next = table_seq_next,
.stop = table_seq_stop,
.show = table_seq_show,
};
static const struct seq_operations format3_seq_ops = {
.start = table_seq_start,
.next = table_seq_next,
.stop = table_seq_stop,
.show = table_seq_show,
};
static const struct file_operations format1_fops;
static const struct file_operations format2_fops;
static const struct file_operations format3_fops;
static int table_open(struct inode *inode, struct file *file)
{
struct seq_file *seq;
int ret = -1;
if (file->f_op == &format1_fops)
ret = seq_open(file, &format1_seq_ops);
else if (file->f_op == &format2_fops)
ret = seq_open(file, &format2_seq_ops);
else if (file->f_op == &format3_fops)
ret = seq_open(file, &format3_seq_ops);
if (ret)
return ret;
seq = file->private_data;
seq->private = inode->i_private; /* the dlm_ls */
return 0;
}
static const struct file_operations format1_fops = {
.owner = THIS_MODULE,
.open = table_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release
};
static const struct file_operations format2_fops = {
.owner = THIS_MODULE,
.open = table_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release
};
static const struct file_operations format3_fops = {
.owner = THIS_MODULE,
.open = table_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release
};
/*
* dump lkb's on the ls_waiters list
*/
static int waiters_open(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return 0;
}
static ssize_t waiters_read(struct file *file, char __user *userbuf,
size_t count, loff_t *ppos)
{
struct dlm_ls *ls = file->private_data;
struct dlm_lkb *lkb;
size_t len = DLM_DEBUG_BUF_LEN, pos = 0, ret, rv;
mutex_lock(&debug_buf_lock);
mutex_lock(&ls->ls_waiters_mutex);
memset(debug_buf, 0, sizeof(debug_buf));
list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
ret = snprintf(debug_buf + pos, len - pos, "%x %d %d %s\n",
lkb->lkb_id, lkb->lkb_wait_type,
lkb->lkb_nodeid, lkb->lkb_resource->res_name);
if (ret >= len - pos)
break;
pos += ret;
}
mutex_unlock(&ls->ls_waiters_mutex);
rv = simple_read_from_buffer(userbuf, count, ppos, debug_buf, pos);
mutex_unlock(&debug_buf_lock);
return rv;
}
static const struct file_operations waiters_fops = {
.owner = THIS_MODULE,
.open = waiters_open,
.read = waiters_read
};
void dlm_delete_debug_file(struct dlm_ls *ls)
{
if (ls->ls_debug_rsb_dentry)
debugfs_remove(ls->ls_debug_rsb_dentry);
if (ls->ls_debug_waiters_dentry)
debugfs_remove(ls->ls_debug_waiters_dentry);
if (ls->ls_debug_locks_dentry)
debugfs_remove(ls->ls_debug_locks_dentry);
if (ls->ls_debug_all_dentry)
debugfs_remove(ls->ls_debug_all_dentry);
}
int dlm_create_debug_file(struct dlm_ls *ls)
{
char name[DLM_LOCKSPACE_LEN+8];
/* format 1 */
ls->ls_debug_rsb_dentry = debugfs_create_file(ls->ls_name,
S_IFREG | S_IRUGO,
dlm_root,
ls,
&format1_fops);
if (!ls->ls_debug_rsb_dentry)
goto fail;
/* format 2 */
memset(name, 0, sizeof(name));
snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_locks", ls->ls_name);
ls->ls_debug_locks_dentry = debugfs_create_file(name,
S_IFREG | S_IRUGO,
dlm_root,
ls,
&format2_fops);
if (!ls->ls_debug_locks_dentry)
goto fail;
/* format 3 */
memset(name, 0, sizeof(name));
snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_all", ls->ls_name);
ls->ls_debug_all_dentry = debugfs_create_file(name,
S_IFREG | S_IRUGO,
dlm_root,
ls,
&format3_fops);
if (!ls->ls_debug_all_dentry)
goto fail;
memset(name, 0, sizeof(name));
snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_waiters", ls->ls_name);
ls->ls_debug_waiters_dentry = debugfs_create_file(name,
S_IFREG | S_IRUGO,
dlm_root,
ls,
&waiters_fops);
if (!ls->ls_debug_waiters_dentry)
goto fail;
return 0;
fail:
dlm_delete_debug_file(ls);
return -ENOMEM;
}
int __init dlm_register_debugfs(void)
{
mutex_init(&debug_buf_lock);
dlm_root = debugfs_create_dir("dlm", NULL);
return dlm_root ? 0 : -ENOMEM;
}
void dlm_unregister_debugfs(void)
{
debugfs_remove(dlm_root);
}