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/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* Copyright (C) 2005 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#ifndef O2CLUSTER_MASKLOG_H
#define O2CLUSTER_MASKLOG_H
/*
* For now this is a trivial wrapper around printk() that gives the critical
* ability to enable sets of debugging output at run-time. In the future this
* will almost certainly be redirected to relayfs so that it can pay a
* substantially lower heisenberg tax.
*
* Callers associate the message with a bitmask and a global bitmask is
* maintained with help from /proc. If any of the bits match the message is
* output.
*
* We must have efficient bit tests on i386 and it seems gcc still emits crazy
* code for the 64bit compare. It emits very good code for the dual unsigned
* long tests, though, completely avoiding tests that can never pass if the
* caller gives a constant bitmask that fills one of the longs with all 0s. So
* the desire is to have almost all of the calls decided on by comparing just
* one of the longs. This leads to having infrequently given bits that are
* frequently matched in the high bits.
*
* _ERROR and _NOTICE are used for messages that always go to the console and
* have appropriate KERN_ prefixes. We wrap these in our function instead of
* just calling printk() so that this can eventually make its way through
* relayfs along with the debugging messages. Everything else gets KERN_DEBUG.
* The inline tests and macro dance give GCC the opportunity to quite cleverly
* only emit the appropriage printk() when the caller passes in a constant
* mask, as is almost always the case.
*
* All this bitmask nonsense is managed from the files under
* /sys/fs/o2cb/logmask/. Reading the files gives a straightforward
* indication of which bits are allowed (allow) or denied (off/deny).
* ENTRY deny
* EXIT deny
* TCP off
* MSG off
* SOCKET off
* ERROR allow
* NOTICE allow
*
* Writing changes the state of a given bit and requires a strictly formatted
* single write() call:
*
* write(fd, "allow", 5);
*
* Echoing allow/deny/off string into the logmask files can flip the bits
* on or off as expected; here is the bash script for example:
*
* log_mask="/sys/fs/o2cb/log_mask"
* for node in ENTRY EXIT TCP MSG SOCKET ERROR NOTICE; do
* echo allow >"$log_mask"/"$node"
* done
*
* The debugfs.ocfs2 tool can also flip the bits with the -l option:
*
* debugfs.ocfs2 -l TCP allow
*/
/* for task_struct */
#include <linux/sched.h>
/* bits that are frequently given and infrequently matched in the low word */
/* NOTE: If you add a flag, you need to also update masklog.c! */
#define ML_TCP 0x0000000000000004ULL /* net cluster/tcp.c */
#define ML_MSG 0x0000000000000008ULL /* net network messages */
#define ML_SOCKET 0x0000000000000010ULL /* net socket lifetime */
#define ML_HEARTBEAT 0x0000000000000020ULL /* hb all heartbeat tracking */
#define ML_HB_BIO 0x0000000000000040ULL /* hb io tracing */
#define ML_DLMFS 0x0000000000000080ULL /* dlm user dlmfs */
#define ML_DLM 0x0000000000000100ULL /* dlm general debugging */
#define ML_DLM_DOMAIN 0x0000000000000200ULL /* dlm domain debugging */
#define ML_DLM_THREAD 0x0000000000000400ULL /* dlm domain thread */
#define ML_DLM_MASTER 0x0000000000000800ULL /* dlm master functions */
#define ML_DLM_RECOVERY 0x0000000000001000ULL /* dlm master functions */
#define ML_AIO 0x0000000000002000ULL /* ocfs2 aio read and write */
#define ML_JOURNAL 0x0000000000004000ULL /* ocfs2 journalling functions */
#define ML_DLM_GLUE 0x0000000000080000ULL /* ocfs2 dlm glue layer */
#define ML_BH_IO 0x0000000000100000ULL /* ocfs2 buffer I/O */
#define ML_UPTODATE 0x0000000000200000ULL /* ocfs2 caching sequence #'s */
#define ML_VOTE 0x0000000001000000ULL /* ocfs2 node messaging */
#define ML_CONN 0x0000000004000000ULL /* net connection management */
#define ML_QUORUM 0x0000000008000000ULL /* net connection quorum */
#define ML_BASTS 0x0000000100000000ULL /* dlmglue asts and basts */
#define ML_CLUSTER 0x0000000400000000ULL /* cluster stack */
/* bits that are infrequently given and frequently matched in the high word */
#define ML_ERROR 0x1000000000000000ULL /* sent to KERN_ERR */
#define ML_NOTICE 0x2000000000000000ULL /* setn to KERN_NOTICE */
#define ML_KTHREAD 0x4000000000000000ULL /* kernel thread activity */
#define MLOG_INITIAL_AND_MASK (ML_ERROR|ML_NOTICE)
#ifndef MLOG_MASK_PREFIX
#define MLOG_MASK_PREFIX 0
#endif
/*
* When logging is disabled, force the bit test to 0 for anything other
* than errors and notices, allowing gcc to remove the code completely.
* When enabled, allow all masks.
*/
#if defined(CONFIG_OCFS2_DEBUG_MASKLOG)
#define ML_ALLOWED_BITS ~0
#else
#define ML_ALLOWED_BITS (ML_ERROR|ML_NOTICE)
#endif
#define MLOG_MAX_BITS 64
struct mlog_bits {
unsigned long words[MLOG_MAX_BITS / BITS_PER_LONG];
};
extern struct mlog_bits mlog_and_bits, mlog_not_bits;
#if BITS_PER_LONG == 32
#define __mlog_test_u64(mask, bits) \
( (u32)(mask & 0xffffffff) & bits.words[0] || \
((u64)(mask) >> 32) & bits.words[1] )
#define __mlog_set_u64(mask, bits) do { \
bits.words[0] |= (u32)(mask & 0xffffffff); \
bits.words[1] |= (u64)(mask) >> 32; \
} while (0)
#define __mlog_clear_u64(mask, bits) do { \
bits.words[0] &= ~((u32)(mask & 0xffffffff)); \
bits.words[1] &= ~((u64)(mask) >> 32); \
} while (0)
#define MLOG_BITS_RHS(mask) { \
{ \
[0] = (u32)(mask & 0xffffffff), \
[1] = (u64)(mask) >> 32, \
} \
}
#else /* 32bit long above, 64bit long below */
#define __mlog_test_u64(mask, bits) ((mask) & bits.words[0])
#define __mlog_set_u64(mask, bits) do { \
bits.words[0] |= (mask); \
} while (0)
#define __mlog_clear_u64(mask, bits) do { \
bits.words[0] &= ~(mask); \
} while (0)
#define MLOG_BITS_RHS(mask) { { (mask) } }
#endif
/*
* smp_processor_id() "helpfully" screams when called outside preemptible
* regions in current kernels. sles doesn't have the variants that don't
* scream. just do this instead of trying to guess which we're building
* against.. *sigh*.
*/
#define __mlog_cpu_guess ({ \
unsigned long _cpu = get_cpu(); \
put_cpu(); \
_cpu; \
})
/* In the following two macros, the whitespace after the ',' just
* before ##args is intentional. Otherwise, gcc 2.95 will eat the
* previous token if args expands to nothing.
*/
#define __mlog_printk(level, fmt, args...) \
printk(level "(%s,%u,%lu):%s:%d " fmt, current->comm, \
task_pid_nr(current), __mlog_cpu_guess, \
__PRETTY_FUNCTION__, __LINE__ , ##args)
#define mlog(mask, fmt, args...) do { \
u64 __m = MLOG_MASK_PREFIX | (mask); \
if ((__m & ML_ALLOWED_BITS) && \
__mlog_test_u64(__m, mlog_and_bits) && \
!__mlog_test_u64(__m, mlog_not_bits)) { \
if (__m & ML_ERROR) \
__mlog_printk(KERN_ERR, "ERROR: "fmt , ##args); \
else if (__m & ML_NOTICE) \
__mlog_printk(KERN_NOTICE, fmt , ##args); \
else __mlog_printk(KERN_INFO, fmt , ##args); \
} \
} while (0)
#define mlog_errno(st) do { \
int _st = (st); \
if (_st != -ERESTARTSYS && _st != -EINTR && \
_st != AOP_TRUNCATED_PAGE && _st != -ENOSPC) \
mlog(ML_ERROR, "status = %lld\n", (long long)_st); \
} while (0)
#define mlog_bug_on_msg(cond, fmt, args...) do { \
if (cond) { \
mlog(ML_ERROR, "bug expression: " #cond "\n"); \
mlog(ML_ERROR, fmt, ##args); \
BUG(); \
} \
} while (0)
#include <linux/kobject.h>
#include <linux/sysfs.h>
int mlog_sys_init(struct kset *o2cb_subsys);
void mlog_sys_shutdown(void);
#endif /* O2CLUSTER_MASKLOG_H */
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