From 8740cf4a2f5f7ff7fb6c214e0baf06356b2870b8 Mon Sep 17 00:00:00 2001 From: Ned Bass Date: Tue, 25 Jul 2017 23:09:48 -0700 Subject: [PATCH] Add line info and SET_ERROR() to ZFS debug log Redefine the SET_ERROR macro in terms of __dprintf() so the error return codes get logged as both tracepoint events (if tracepoints are enabled) and as ZFS debug log entries. This also allows us to use the same definition of SET_ERROR() in kernel and user space. Define a new debug flag ZFS_DEBUG_SET_ERROR=512 that may be bitwise or'd into zfs_flags. Setting this flag enables both dprintf() and SET_ERROR() messages in the debug log. That is, setting ZFS_DEBUG_SET_ERROR and ZFS_DEBUG_DPRINTF|ZFS_DEBUG_SET_ERROR are equivalent (this was done for sake of simplicity). Leaving ZFS_DEBUG_SET_ERROR unset suppresses the SET_ERROR() messages which helps avoid cluttering up the logs. To enable SET_ERROR() logging, run: echo 1 > /sys/module/zfs/parameters/zfs_dbgmsg_enable echo 512 > /sys/module/zfs/parameters/zfs_flags Remove the zfs_set_error_class tracepoints event class since SET_ERROR() now uses __dprintf(). This sacrifices a bit of granularity when selecting individual tracepoint events to enable but it makes the code simpler. Include file, function, and line number information in debug log entries. The information is now added to the message buffer in __dprintf() and as a result the zfs_dprintf_class tracepoints event class was changed from a 4 parameter interface to a single parameter. Reviewed-by: Brian Behlendorf Signed-off-by: Ned Bass Closes #6400 --- include/sys/sdt.h | 20 ++------- include/sys/trace_dbgmsg.h | 77 +++----------------------------- include/sys/zfs_context.h | 9 ---- include/sys/zfs_debug.h | 1 + man/man5/zfs-module-parameters.5 | 6 +++ module/zfs/zfs_debug.c | 26 ++++++++--- 6 files changed, 37 insertions(+), 102 deletions(-) diff --git a/include/sys/sdt.h b/include/sys/sdt.h index 56efa1b399..9704072cb7 100644 --- a/include/sys/sdt.h +++ b/include/sys/sdt.h @@ -34,13 +34,8 @@ #define ZFS_PROBE2(a, c, e) ((void) 0) #define ZFS_PROBE3(a, c, e, g) ((void) 0) #define ZFS_PROBE4(a, c, e, g, i) ((void) 0) -#define ZFS_SET_ERROR(err) ((void) 0) -#else - -#if defined(HAVE_DECLARE_EVENT_CLASS) - -#include +#endif /* _KERNEL */ /* * The set-error SDT probe is extra static, in that we declare its fake @@ -55,16 +50,9 @@ * twice, so it should not have side effects (e.g. something like: * "return (SET_ERROR(log_error(EINVAL, info)));" would log the error twice). */ -#define SET_ERROR(err) \ - (trace_zfs_set__error(__FILE__, __func__, __LINE__, err), err) - -#else - +extern void __set_error(const char *file, const char *func, int line, int err); #undef SET_ERROR -#define SET_ERROR(err) (err) - -#endif /* HAVE_DECLARE_EVENT_CLASS */ - -#endif /* _KERNEL */ +#define SET_ERROR(err) \ + (__set_error(__FILE__, __func__, __LINE__, err), err) #endif /* _SYS_SDT_H */ diff --git a/include/sys/trace_dbgmsg.h b/include/sys/trace_dbgmsg.h index 08d96c59c2..a4aab1e63f 100644 --- a/include/sys/trace_dbgmsg.h +++ b/include/sys/trace_dbgmsg.h @@ -37,92 +37,29 @@ */ /* - * Generic support for four argument tracepoints of the form: + * Generic support for one argument tracepoints of the form: * - * DTRACE_PROBE4(..., - * const char *, ..., - * const char *, ..., - * int, ..., + * DTRACE_PROBE1(..., * const char *, ...); */ /* BEGIN CSTYLED */ DECLARE_EVENT_CLASS(zfs_dprintf_class, - TP_PROTO(const char *file, const char *function, int line, - const char *msg), - TP_ARGS(file, function, line, msg), + TP_PROTO(const char *msg), + TP_ARGS(msg), TP_STRUCT__entry( - __string(file, file) - __string(function, function) - __field(int, line) __string(msg, msg) ), TP_fast_assign( - __assign_str(file, strchr(file, '/') ? - strrchr(file, '/') + 1 : file) - __assign_str(function, function); - __entry->line = line; __assign_str(msg, msg); ), - TP_printk("%s:%d:%s(): %s", __get_str(file), __entry->line, - __get_str(function), __get_str(msg)) + TP_printk("%s", __get_str(msg)) ); /* END CSTYLED */ /* BEGIN CSTYLED */ #define DEFINE_DPRINTF_EVENT(name) \ DEFINE_EVENT(zfs_dprintf_class, name, \ - TP_PROTO(const char *file, const char *function, int line, \ - const char *msg), \ - TP_ARGS(file, function, line, msg)) + TP_PROTO(const char *msg), \ + TP_ARGS(msg)) /* END CSTYLED */ DEFINE_DPRINTF_EVENT(zfs_zfs__dprintf); - -/* - * Generic support for four argument tracepoints of the form: - * - * DTRACE_PROBE4(..., - * const char *, ..., - * const char *, ..., - * int, ..., - * uintptr_t, ...); - */ -/* BEGIN CSTYLED */ -DECLARE_EVENT_CLASS(zfs_set_error_class, - TP_PROTO(const char *file, const char *function, int line, - uintptr_t error), - TP_ARGS(file, function, line, error), - TP_STRUCT__entry( - __string(file, file) - __string(function, function) - __field(int, line) - __field(uintptr_t, error) - ), - TP_fast_assign( - __assign_str(file, strchr(file, '/') ? - strrchr(file, '/') + 1 : file) - __assign_str(function, function); - __entry->line = line; - __entry->error = error; - ), - TP_printk("%s:%d:%s(): error 0x%lx", __get_str(file), __entry->line, - __get_str(function), __entry->error) -); -/* END CSTYLED */ - -/* BEGIN CSTYLED */ -#ifdef TP_CONDITION -#define DEFINE_SET_ERROR_EVENT(name) \ -DEFINE_EVENT_CONDITION(zfs_set_error_class, name, \ - TP_PROTO(const char *file, const char *function, int line, \ - uintptr_t error), \ - TP_ARGS(file, function, line, error), \ - TP_CONDITION(error)) -#else -#define DEFINE_SET_ERROR_EVENT(name) \ -DEFINE_EVENT(zfs_set_error_class, name, \ - TP_PROTO(const char *file, const char *function, int line, \ - uintptr_t error), \ - TP_ARGS(file, function, line, error)) -#endif -/* END CSTYLED */ -DEFINE_SET_ERROR_EVENT(zfs_set__error); diff --git a/include/sys/zfs_context.h b/include/sys/zfs_context.h index 6163b2fbfb..4fe35342de 100644 --- a/include/sys/zfs_context.h +++ b/include/sys/zfs_context.h @@ -206,15 +206,6 @@ extern int aok; ZFS_PROBE4(#a, (unsigned long)c, (unsigned long)e, (unsigned long)g, \ (unsigned long)i) -/* - * We use the comma operator so that this macro can be used without much - * additional code. For example, "return (EINVAL);" becomes - * "return (SET_ERROR(EINVAL));". Note that the argument will be evaluated - * twice, so it should not have side effects (e.g. something like: - * "return (SET_ERROR(log_error(EINVAL, info)));" would log the error twice). - */ -#define SET_ERROR(err) (ZFS_SET_ERROR(err), err) - /* * Threads. TS_STACK_MIN is dictated by the minimum allowed pthread stack * size. While TS_STACK_MAX is somewhat arbitrary, it was selected to be diff --git a/include/sys/zfs_debug.h b/include/sys/zfs_debug.h index b9b06a5ad1..226aaa2b84 100644 --- a/include/sys/zfs_debug.h +++ b/include/sys/zfs_debug.h @@ -51,6 +51,7 @@ extern int zfs_free_leak_on_eio; #define ZFS_DEBUG_ZIO_FREE (1 << 6) #define ZFS_DEBUG_HISTOGRAM_VERIFY (1 << 7) #define ZFS_DEBUG_METASLAB_VERIFY (1 << 8) +#define ZFS_DEBUG_SET_ERROR (1 << 9) extern void __dprintf(const char *file, const char *func, int line, const char *fmt, ...); diff --git a/man/man5/zfs-module-parameters.5 b/man/man5/zfs-module-parameters.5 index 0447debf73..f7bb2eb8cc 100644 --- a/man/man5/zfs-module-parameters.5 +++ b/man/man5/zfs-module-parameters.5 @@ -1258,6 +1258,12 @@ _ _ 128 ZFS_DEBUG_HISTOGRAM_VERIFY Enable extra spacemap histogram verifications. +_ +256 ZFS_DEBUG_METASLAB_VERIFY + Verify space accounting on disk matches in-core range_trees. +_ +512 ZFS_DEBUG_SET_ERROR + Enable SET_ERROR and dprintf entries in the debug log. .TE .sp * Requires debug build. diff --git a/module/zfs/zfs_debug.c b/module/zfs/zfs_debug.c index 90c1d7361d..d1dba3f8f5 100644 --- a/module/zfs/zfs_debug.c +++ b/module/zfs/zfs_debug.c @@ -161,6 +161,13 @@ __zfs_dbgmsg(char *buf) mutex_exit(&zfs_dbgmsgs_lock); } +void +__set_error(const char *file, const char *func, int line, int err) +{ + if (zfs_flags & ZFS_DEBUG_SET_ERROR) + __dprintf(file, func, line, "error %lu", err); +} + #ifdef _KERNEL void __dprintf(const char *file, const char *func, int line, const char *fmt, ...) @@ -170,8 +177,10 @@ __dprintf(const char *file, const char *func, int line, const char *fmt, ...) size_t size; char *buf; char *nl; + int i; - if (!zfs_dbgmsg_enable && !(zfs_flags & ZFS_DEBUG_DPRINTF)) + if (!zfs_dbgmsg_enable && + !(zfs_flags & (ZFS_DEBUG_DPRINTF | ZFS_DEBUG_SET_ERROR))) return; size = 1024; @@ -187,9 +196,13 @@ __dprintf(const char *file, const char *func, int line, const char *fmt, ...) newfile = file; } - va_start(adx, fmt); - (void) vsnprintf(buf, size, fmt, adx); - va_end(adx); + i = snprintf(buf, size, "%s:%d:%s(): ", newfile, line, func); + + if (i < size) { + va_start(adx, fmt); + (void) vsnprintf(buf + i, size - i, fmt, adx); + va_end(adx); + } /* * Get rid of trailing newline. @@ -209,9 +222,8 @@ __dprintf(const char *file, const char *func, int line, const char *fmt, ...) * # Dump the ring buffer. * $ cat /sys/kernel/debug/tracing/trace */ - if (zfs_flags & ZFS_DEBUG_DPRINTF) - DTRACE_PROBE4(zfs__dprintf, - char *, newfile, char *, func, int, line, char *, buf); + if (zfs_flags & (ZFS_DEBUG_DPRINTF | ZFS_DEBUG_SET_ERROR)) + DTRACE_PROBE1(zfs__dprintf, char *, buf); /* * To get this data enable the zfs debug log as shown: