kernel-ark/fs/dlm/debug_fs.c
Arnd Bergmann 6038f373a3 llseek: automatically add .llseek fop
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
2010-10-15 15:53:27 +02:00

732 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 <linux/slab.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_bastmode,
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,
.llseek = default_llseek,
};
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);
}