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1/* SPDX-License-Identifier: GPL-2.0 */2/*3 * User-space visible declarations for NFS client per-mount4 * point statistics5 *6 * Copyright (C) 2005, 2006 Chuck Lever <cel@netapp.com>7 *8 * NFS client per-mount statistics provide information about the9 * health of the NFS client and the health of each NFS mount point.10 * Generally these are not for detailed problem diagnosis, but11 * simply to indicate that there is a problem.12 *13 * These counters are not meant to be human-readable, but are meant14 * to be integrated into system monitoring tools such as "sar" and15 * "iostat". As such, the counters are sampled by the tools over16 * time, and are never zeroed after a file system is mounted.17 * Moving averages can be computed by the tools by taking the18 * difference between two instantaneous samples and dividing that19 * by the time between the samples.20 */21 22#ifndef _LINUX_NFS_IOSTAT23#define _LINUX_NFS_IOSTAT24 25#define NFS_IOSTAT_VERS "1.1"26 27/*28 * NFS byte counters29 *30 * 1. SERVER - the number of payload bytes read from or written31 * to the server by the NFS client via an NFS READ or WRITE32 * request.33 *34 * 2. NORMAL - the number of bytes read or written by applications35 * via the read(2) and write(2) system call interfaces.36 *37 * 3. DIRECT - the number of bytes read or written from files38 * opened with the O_DIRECT flag.39 *40 * These counters give a view of the data throughput into and out41 * of the NFS client. Comparing the number of bytes requested by42 * an application with the number of bytes the client requests from43 * the server can provide an indication of client efficiency44 * (per-op, cache hits, etc).45 *46 * These counters can also help characterize which access methods47 * are in use. DIRECT by itself shows whether there is any O_DIRECT48 * traffic. NORMAL + DIRECT shows how much data is going through49 * the system call interface. A large amount of SERVER traffic50 * without much NORMAL or DIRECT traffic shows that applications51 * are using mapped files.52 *53 * NFS page counters54 *55 * These count the number of pages read or written via nfs_readpage(),56 * nfs_readpages(), or their write equivalents.57 *58 * NB: When adding new byte counters, please include the measured59 * units in the name of each byte counter to help users of this60 * interface determine what exactly is being counted.61 */62enum nfs_stat_bytecounters {63 NFSIOS_NORMALREADBYTES = 0,64 NFSIOS_NORMALWRITTENBYTES,65 NFSIOS_DIRECTREADBYTES,66 NFSIOS_DIRECTWRITTENBYTES,67 NFSIOS_SERVERREADBYTES,68 NFSIOS_SERVERWRITTENBYTES,69 NFSIOS_READPAGES,70 NFSIOS_WRITEPAGES,71 __NFSIOS_BYTESMAX,72};73 74/*75 * NFS event counters76 *77 * These counters provide a low-overhead way of monitoring client78 * activity without enabling NFS trace debugging. The counters79 * show the rate at which VFS requests are made, and how often the80 * client invalidates its data and attribute caches. This allows81 * system administrators to monitor such things as how close-to-open82 * is working, and answer questions such as "why are there so many83 * GETATTR requests on the wire?"84 *85 * They also count anamolous events such as short reads and writes,86 * silly renames due to close-after-delete, and operations that87 * change the size of a file (such operations can often be the88 * source of data corruption if applications aren't using file89 * locking properly).90 */91enum nfs_stat_eventcounters {92 NFSIOS_INODEREVALIDATE = 0,93 NFSIOS_DENTRYREVALIDATE,94 NFSIOS_DATAINVALIDATE,95 NFSIOS_ATTRINVALIDATE,96 NFSIOS_VFSOPEN,97 NFSIOS_VFSLOOKUP,98 NFSIOS_VFSACCESS,99 NFSIOS_VFSUPDATEPAGE,100 NFSIOS_VFSREADPAGE,101 NFSIOS_VFSREADPAGES,102 NFSIOS_VFSWRITEPAGE,103 NFSIOS_VFSWRITEPAGES,104 NFSIOS_VFSGETDENTS,105 NFSIOS_VFSSETATTR,106 NFSIOS_VFSFLUSH,107 NFSIOS_VFSFSYNC,108 NFSIOS_VFSLOCK,109 NFSIOS_VFSRELEASE,110 NFSIOS_CONGESTIONWAIT,111 NFSIOS_SETATTRTRUNC,112 NFSIOS_EXTENDWRITE,113 NFSIOS_SILLYRENAME,114 NFSIOS_SHORTREAD,115 NFSIOS_SHORTWRITE,116 NFSIOS_DELAY,117 NFSIOS_PNFS_READ,118 NFSIOS_PNFS_WRITE,119 __NFSIOS_COUNTSMAX,120};121 122#endif /* _LINUX_NFS_IOSTAT */123