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root/fs/ocfs2/cluster/masklog.h

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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 hidden from the /proc interface so that Joel
 * doesn't have an aneurism.  Reading the file gives a straight forward
 * indication of which bits are on or off:
 *      ENTRY off
 *      EXIT off
 *      TCP off
 *      MSG off
 *      SOCKET off
 *      ERROR off
 *      NOTICE on
 *
 * Writing changes the state of a given bit and requires a strictly formatted
 * single write() call:
 *
 *      write(fd, "ENTRY on", 8);
 *
 * would turn the entry bit on.  "1" is also accepted in the place of "on", and
 * "off" and "0" behave as expected.
 *
 * Some trivial shell can flip all the bits on or off:
 *
 * log_mask="/proc/fs/ocfs2_nodemanager/log_mask"
 * cat $log_mask | (
 *      while read bit status; do
 *              # $1 is "on" or "off", say
 *              echo "$bit $1" > $log_mask
 *      done
 * )
 */

/* 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 mlog.c! */
#define ML_ENTRY        0x0000000000000001ULL /* func call entry */
#define ML_EXIT         0x0000000000000002ULL /* func call exit */
#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_DISK_ALLOC   0x0000000000008000ULL /* ocfs2 disk allocation */
#define ML_SUPER        0x0000000000010000ULL /* ocfs2 mount / umount */
#define ML_FILE_IO      0x0000000000020000ULL /* ocfs2 file I/O */
#define ML_EXTENT_MAP   0x0000000000040000ULL /* ocfs2 extent map caching */
#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_NAMEI        0x0000000000400000ULL /* ocfs2 directory / namespace */
#define ML_INODE        0x0000000000800000ULL /* ocfs2 inode manipulation */
#define ML_VOTE         0x0000000001000000ULL /* ocfs2 node messaging  */
#define ML_DCACHE       0x0000000002000000ULL /* ocfs2 dcache operations */
#define ML_CONN         0x0000000004000000ULL /* net connection management */
#define ML_QUORUM       0x0000000008000000ULL /* net connection quorum */
#define ML_EXPORT       0x0000000010000000ULL /* ocfs2 export operations */
#define ML_XATTR        0x0000000020000000ULL /* ocfs2 extended attributes */
/* bits that are infrequently given and frequently matched in the high word */
#define ML_ERROR        0x0000000100000000ULL /* sent to KERN_ERR */
#define ML_NOTICE       0x0000000200000000ULL /* setn to KERN_NOTICE */
#define ML_KTHREAD      0x0000000400000000ULL /* kernel thread activity */

#define MLOG_INITIAL_AND_MASK (ML_ERROR|ML_NOTICE)
#define MLOG_INITIAL_NOT_MASK (ML_ENTRY|ML_EXIT)
#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 "(%u,%lu):%s:%d " fmt, 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)

#if defined(CONFIG_OCFS2_DEBUG_MASKLOG)
#define mlog_entry(fmt, args...) do {                                   \
        mlog(ML_ENTRY, "ENTRY:" fmt , ##args);                          \
} while (0)

#define mlog_entry_void() do {                                          \
        mlog(ML_ENTRY, "ENTRY:\n");                                     \
} while (0)

/*
 * We disable this for sparse.
 */
#if !defined(__CHECKER__)
#define mlog_exit(st) do {                                                   \
        if (__builtin_types_compatible_p(typeof(st), unsigned long))         \
                mlog(ML_EXIT, "EXIT: %lu\n", (unsigned long) (st));          \
        else if (__builtin_types_compatible_p(typeof(st), signed long))      \
                mlog(ML_EXIT, "EXIT: %ld\n", (signed long) (st));            \
        else if (__builtin_types_compatible_p(typeof(st), unsigned int)      \
                 || __builtin_types_compatible_p(typeof(st), unsigned short) \
                 || __builtin_types_compatible_p(typeof(st), unsigned char)) \
                mlog(ML_EXIT, "EXIT: %u\n", (unsigned int) (st));            \
        else if (__builtin_types_compatible_p(typeof(st), signed int)        \
                 || __builtin_types_compatible_p(typeof(st), signed short)   \
                 || __builtin_types_compatible_p(typeof(st), signed char))   \
                mlog(ML_EXIT, "EXIT: %d\n", (signed int) (st));              \
        else if (__builtin_types_compatible_p(typeof(st), long long))        \
                mlog(ML_EXIT, "EXIT: %lld\n", (long long) (st));             \
        else                                                                 \
                mlog(ML_EXIT, "EXIT: %llu\n", (unsigned long long) (st));    \
} while (0)
#else
#define mlog_exit(st) do {                                                   \
        mlog(ML_EXIT, "EXIT: %lld\n", (long long) (st));                     \
} while (0)
#endif

#define mlog_exit_ptr(ptr) do {                                         \
        mlog(ML_EXIT, "EXIT: %p\n", ptr);                               \
} while (0)

#define mlog_exit_void() do {                                           \
        mlog(ML_EXIT, "EXIT\n");                                        \
} while (0)
#else
#define mlog_entry(...)  do { } while (0)
#define mlog_entry_void(...)  do { } while (0)
#define mlog_exit(...)  do { } while (0)
#define mlog_exit_ptr(...)  do { } while (0)
#define mlog_exit_void(...)  do { } while (0)
#endif  /* defined(CONFIG_OCFS2_DEBUG_MASKLOG) */

#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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