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/* -*- mode: c; c-basic-offset: 8; -*-
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* vim: noexpandtab sw=8 ts=8 sts=0:
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* Copyright (C) 2005 Oracle. All rights reserved.
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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#ifndef O2CLUSTER_MASKLOG_H
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#define O2CLUSTER_MASKLOG_H
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* For now this is a trivial wrapper around printk() that gives the critical
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* ability to enable sets of debugging output at run-time. In the future this
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* will almost certainly be redirected to relayfs so that it can pay a
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* substantially lower heisenberg tax.
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* Callers associate the message with a bitmask and a global bitmask is
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* maintained with help from /proc. If any of the bits match the message is
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* We must have efficient bit tests on i386 and it seems gcc still emits crazy
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* code for the 64bit compare. It emits very good code for the dual unsigned
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* long tests, though, completely avoiding tests that can never pass if the
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* caller gives a constant bitmask that fills one of the longs with all 0s. So
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* the desire is to have almost all of the calls decided on by comparing just
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* one of the longs. This leads to having infrequently given bits that are
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* frequently matched in the high bits.
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* _ERROR and _NOTICE are used for messages that always go to the console and
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* have appropriate KERN_ prefixes. We wrap these in our function instead of
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* just calling printk() so that this can eventually make its way through
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* relayfs along with the debugging messages. Everything else gets KERN_DEBUG.
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* The inline tests and macro dance give GCC the opportunity to quite cleverly
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* only emit the appropriage printk() when the caller passes in a constant
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* mask, as is almost always the case.
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* All this bitmask nonsense is managed from the files under
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* /sys/fs/o2cb/logmask/. Reading the files gives a straightforward
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* indication of which bits are allowed (allow) or denied (off/deny).
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* Writing changes the state of a given bit and requires a strictly formatted
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* single write() call:
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* write(fd, "allow", 5);
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* Echoing allow/deny/off string into the logmask files can flip the bits
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* on or off as expected; here is the bash script for example:
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* log_mask="/sys/fs/o2cb/log_mask"
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* for node in ENTRY EXIT TCP MSG SOCKET ERROR NOTICE; do
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* echo allow >"$log_mask"/"$node"
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* The debugfs.ocfs2 tool can also flip the bits with the -l option:
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* debugfs.ocfs2 -l TCP allow
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#include <linux/sched.h>
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/* bits that are frequently given and infrequently matched in the low word */
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/* NOTE: If you add a flag, you need to also update masklog.c! */
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#define ML_TCP 0x0000000000000001ULL /* net cluster/tcp.c */
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#define ML_MSG 0x0000000000000002ULL /* net network messages */
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#define ML_SOCKET 0x0000000000000004ULL /* net socket lifetime */
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#define ML_HEARTBEAT 0x0000000000000008ULL /* hb all heartbeat tracking */
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#define ML_HB_BIO 0x0000000000000010ULL /* hb io tracing */
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#define ML_DLMFS 0x0000000000000020ULL /* dlm user dlmfs */
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#define ML_DLM 0x0000000000000040ULL /* dlm general debugging */
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#define ML_DLM_DOMAIN 0x0000000000000080ULL /* dlm domain debugging */
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#define ML_DLM_THREAD 0x0000000000000100ULL /* dlm domain thread */
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#define ML_DLM_MASTER 0x0000000000000200ULL /* dlm master functions */
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#define ML_DLM_RECOVERY 0x0000000000000400ULL /* dlm master functions */
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#define ML_DLM_GLUE 0x0000000000000800ULL /* ocfs2 dlm glue layer */
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#define ML_VOTE 0x0000000000001000ULL /* ocfs2 node messaging */
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#define ML_CONN 0x0000000000002000ULL /* net connection management */
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#define ML_QUORUM 0x0000000000004000ULL /* net connection quorum */
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#define ML_BASTS 0x0000000000008000ULL /* dlmglue asts and basts */
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#define ML_CLUSTER 0x0000000000010000ULL /* cluster stack */
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/* bits that are infrequently given and frequently matched in the high word */
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#define ML_ERROR 0x1000000000000000ULL /* sent to KERN_ERR */
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#define ML_NOTICE 0x2000000000000000ULL /* setn to KERN_NOTICE */
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#define ML_KTHREAD 0x4000000000000000ULL /* kernel thread activity */
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#define MLOG_INITIAL_AND_MASK (ML_ERROR|ML_NOTICE)
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#ifndef MLOG_MASK_PREFIX
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#define MLOG_MASK_PREFIX 0
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* When logging is disabled, force the bit test to 0 for anything other
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* than errors and notices, allowing gcc to remove the code completely.
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* When enabled, allow all masks.
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#if defined(CONFIG_OCFS2_DEBUG_MASKLOG)
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#define ML_ALLOWED_BITS ~0
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#define ML_ALLOWED_BITS (ML_ERROR|ML_NOTICE)
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#define MLOG_MAX_BITS 64
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unsigned long words[MLOG_MAX_BITS / BITS_PER_LONG];
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extern struct mlog_bits mlog_and_bits, mlog_not_bits;
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#if BITS_PER_LONG == 32
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#define __mlog_test_u64(mask, bits) \
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( (u32)(mask & 0xffffffff) & bits.words[0] || \
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((u64)(mask) >> 32) & bits.words[1] )
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#define __mlog_set_u64(mask, bits) do { \
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bits.words[0] |= (u32)(mask & 0xffffffff); \
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bits.words[1] |= (u64)(mask) >> 32; \
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#define __mlog_clear_u64(mask, bits) do { \
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bits.words[0] &= ~((u32)(mask & 0xffffffff)); \
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bits.words[1] &= ~((u64)(mask) >> 32); \
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#define MLOG_BITS_RHS(mask) { \
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[0] = (u32)(mask & 0xffffffff), \
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[1] = (u64)(mask) >> 32, \
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#else /* 32bit long above, 64bit long below */
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#define __mlog_test_u64(mask, bits) ((mask) & bits.words[0])
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#define __mlog_set_u64(mask, bits) do { \
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bits.words[0] |= (mask); \
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#define __mlog_clear_u64(mask, bits) do { \
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bits.words[0] &= ~(mask); \
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#define MLOG_BITS_RHS(mask) { { (mask) } }
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* smp_processor_id() "helpfully" screams when called outside preemptible
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* regions in current kernels. sles doesn't have the variants that don't
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* scream. just do this instead of trying to guess which we're building
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#define __mlog_cpu_guess ({ \
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unsigned long _cpu = get_cpu(); \
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/* In the following two macros, the whitespace after the ',' just
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* before ##args is intentional. Otherwise, gcc 2.95 will eat the
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* previous token if args expands to nothing.
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#define __mlog_printk(level, fmt, args...) \
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printk(level "(%s,%u,%lu):%s:%d " fmt, current->comm, \
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task_pid_nr(current), __mlog_cpu_guess, \
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__PRETTY_FUNCTION__, __LINE__ , ##args)
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#define mlog(mask, fmt, args...) do { \
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u64 __m = MLOG_MASK_PREFIX | (mask); \
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if ((__m & ML_ALLOWED_BITS) && \
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__mlog_test_u64(__m, mlog_and_bits) && \
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!__mlog_test_u64(__m, mlog_not_bits)) { \
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if (__m & ML_ERROR) \
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__mlog_printk(KERN_ERR, "ERROR: "fmt , ##args); \
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else if (__m & ML_NOTICE) \
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__mlog_printk(KERN_NOTICE, fmt , ##args); \
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else __mlog_printk(KERN_INFO, fmt , ##args); \
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#define mlog_errno(st) do { \
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if (_st != -ERESTARTSYS && _st != -EINTR && \
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_st != AOP_TRUNCATED_PAGE && _st != -ENOSPC) \
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mlog(ML_ERROR, "status = %lld\n", (long long)_st); \
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#define mlog_bug_on_msg(cond, fmt, args...) do { \
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mlog(ML_ERROR, "bug expression: " #cond "\n"); \
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mlog(ML_ERROR, fmt, ##args); \
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#include <linux/kobject.h>
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#include <linux/sysfs.h>
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int mlog_sys_init(struct kset *o2cb_subsys);
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void mlog_sys_shutdown(void);
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#endif /* O2CLUSTER_MASKLOG_H */