mirror_zfs/include/sys/zfs_debug.h
John Gallagher d12614521a Fixes for procfs files backed by linked lists
There are some issues with the way the seq_file interface is implemented
for kstats backed by linked lists (zfs_dbgmsgs and certain per-pool
debugging info):

* We don't account for the fact that seq_file sometimes visits a node
  multiple times, which results in missing messages when read through
  procfs.
* We don't keep separate state for each reader of a file, so concurrent
  readers will receive incorrect results.
* We don't account for the fact that entries may have been removed from
  the list between read syscalls, so reading from these files in procfs
  can cause the system to crash.

This change fixes these issues and adds procfs_list, a wrapper around a
linked list which abstracts away the details of implementing the
seq_file interface for a list and exposing the contents of the list
through procfs.

Reviewed by: Don Brady <don.brady@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: John Gallagher <john.gallagher@delphix.com>
External-issue: LX-1211
Closes #7819
2018-09-26 11:08:12 -07:00

92 lines
2.4 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
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* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
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*
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* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012, 2017 by Delphix. All rights reserved.
*/
#ifndef _SYS_ZFS_DEBUG_H
#define _SYS_ZFS_DEBUG_H
#ifdef __cplusplus
extern "C" {
#endif
#ifndef TRUE
#define TRUE 1
#endif
#ifndef FALSE
#define FALSE 0
#endif
extern int zfs_flags;
extern int zfs_recover;
extern int zfs_free_leak_on_eio;
extern int zfs_dbgmsg_enable;
#define ZFS_DEBUG_DPRINTF (1 << 0)
#define ZFS_DEBUG_DBUF_VERIFY (1 << 1)
#define ZFS_DEBUG_DNODE_VERIFY (1 << 2)
#define ZFS_DEBUG_SNAPNAMES (1 << 3)
#define ZFS_DEBUG_MODIFY (1 << 4)
/* 1<<5 was previously used, try not to reuse */
#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)
#define ZFS_DEBUG_INDIRECT_REMAP (1 << 10)
extern void __dprintf(const char *file, const char *func,
int line, const char *fmt, ...);
#define zfs_dbgmsg(...) \
if (zfs_dbgmsg_enable) \
__dprintf(__FILE__, __func__, __LINE__, __VA_ARGS__)
#ifdef ZFS_DEBUG
/*
* To enable this:
*
* $ echo 1 >/sys/module/zfs/parameters/zfs_flags
*/
#define dprintf(...) \
if (zfs_flags & ZFS_DEBUG_DPRINTF) \
__dprintf(__FILE__, __func__, __LINE__, __VA_ARGS__)
#else
#define dprintf(...) ((void)0)
#endif /* ZFS_DEBUG */
extern void zfs_panic_recover(const char *fmt, ...);
extern void zfs_dbgmsg_init(void);
extern void zfs_dbgmsg_fini(void);
#ifndef _KERNEL
extern int dprintf_find_string(const char *string);
extern void zfs_dbgmsg_print(const char *tag);
#endif
#ifdef __cplusplus
}
#endif
#endif /* _SYS_ZFS_DEBUG_H */