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Diffstat (limited to 'drivers/staging/zcache/ramster/masklog.h')
| -rw-r--r-- | drivers/staging/zcache/ramster/masklog.h | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/staging/zcache/ramster/masklog.h b/drivers/staging/zcache/ramster/masklog.h new file mode 100644 index 000000000000..918ae110b699 --- /dev/null +++ b/drivers/staging/zcache/ramster/masklog.h @@ -0,0 +1,220 @@ +/* -*- mode: c; c-basic-offset: 8; -*- + * vim: noexpandtab sw=8 ts=8 sts=0: + * + * Copyright (C) 2005, 2012 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 R2CLUSTER_MASKLOG_H +#define R2CLUSTER_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/r2cb/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/r2cb/log_mask" + * for node in ENTRY EXIT TCP MSG SOCKET ERROR NOTICE; do + * echo allow >"$log_mask"/"$node" + * done + * + * The debugfs.ramster tool can also flip the bits with the -l option: + * + * debugfs.ramster -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 0x0000000000000001ULL /* net cluster/tcp.c */ +#define ML_MSG 0x0000000000000002ULL /* net network messages */ +#define ML_SOCKET 0x0000000000000004ULL /* net socket lifetime */ +#define ML_HEARTBEAT 0x0000000000000008ULL /* hb all heartbeat tracking */ +#define ML_HB_BIO 0x0000000000000010ULL /* hb io tracing */ +#define ML_DLMFS 0x0000000000000020ULL /* dlm user dlmfs */ +#define ML_DLM 0x0000000000000040ULL /* dlm general debugging */ +#define ML_DLM_DOMAIN 0x0000000000000080ULL /* dlm domain debugging */ +#define ML_DLM_THREAD 0x0000000000000100ULL /* dlm domain thread */ +#define ML_DLM_MASTER 0x0000000000000200ULL /* dlm master functions */ +#define ML_DLM_RECOVERY 0x0000000000000400ULL /* dlm master functions */ +#define ML_DLM_GLUE 0x0000000000000800ULL /* ramster dlm glue layer */ +#define ML_VOTE 0x0000000000001000ULL /* ramster node messaging */ +#define ML_CONN 0x0000000000002000ULL /* net connection management */ +#define ML_QUORUM 0x0000000000004000ULL /* net connection quorum */ +#define ML_BASTS 0x0000000000008000ULL /* dlmglue asts and basts */ +#define ML_CLUSTER 0x0000000000010000ULL /* 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_RAMSTER_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 r2_mlog_and_bits, r2_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, r2_mlog_and_bits) && \ + !__mlog_test_u64(__m, r2_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 r2_mlog_sys_init(struct kset *r2cb_subsys); +void r2_mlog_sys_shutdown(void); + +#endif /* R2CLUSTER_MASKLOG_H */ |