include/linux/nfs_iostat.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  *  User-space visible declarations for NFS client per-mount
   4  *  point statistics
   5  *
   6  *  Copyright (C) 2005, 2006 Chuck Lever <cel@netapp.com>
   7  *
   8  *  NFS client per-mount statistics provide information about the
   9  *  health of the NFS client and the health of each NFS mount point.
  10  *  Generally these are not for detailed problem diagnosis, but
  11  *  simply to indicate that there is a problem.
  12  *
  13  *  These counters are not meant to be human-readable, but are meant
  14  *  to be integrated into system monitoring tools such as "sar" and
  15  *  "iostat".  As such, the counters are sampled by the tools over
  16  *  time, and are never zeroed after a file system is mounted.
  17  *  Moving averages can be computed by the tools by taking the
  18  *  difference between two instantaneous samples  and dividing that
  19  *  by the time between the samples.
  20  */
  21
  22 #ifndef _LINUX_NFS_IOSTAT
  23 #define _LINUX_NFS_IOSTAT
  24
  25 #define NFS_IOSTAT_VERS         "1.1"
  26
  27 /*
  28  * NFS byte counters
  29  *
  30  * 1.  SERVER - the number of payload bytes read from or written
  31  *     to the server by the NFS client via an NFS READ or WRITE
  32  *     request.
  33  *
  34  * 2.  NORMAL - the number of bytes read or written by applications
  35  *     via the read(2) and write(2) system call interfaces.
  36  *
  37  * 3.  DIRECT - the number of bytes read or written from files
  38  *     opened with the O_DIRECT flag.
  39  *
  40  * These counters give a view of the data throughput into and out
  41  * of the NFS client.  Comparing the number of bytes requested by
  42  * an application with the number of bytes the client requests from
  43  * the server can provide an indication of client efficiency
  44  * (per-op, cache hits, etc).
  45  *
  46  * These counters can also help characterize which access methods
  47  * are in use.  DIRECT by itself shows whether there is any O_DIRECT
  48  * traffic.  NORMAL + DIRECT shows how much data is going through
  49  * the system call interface.  A large amount of SERVER traffic
  50  * without much NORMAL or DIRECT traffic shows that applications
  51  * are using mapped files.
  52  *
  53  * NFS page counters
  54  *
  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 measured
  59  * units in the name of each byte counter to help users of this
  60  * interface determine what exactly is being counted.
  61  */
  62 enum 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 counters
  76  *
  77  * These counters provide a low-overhead way of monitoring client
  78  * activity without enabling NFS trace debugging.  The counters
  79  * show the rate at which VFS requests are made, and how often the
  80  * client invalidates its data and attribute caches.  This allows
  81  * system administrators to monitor such things as how close-to-open
  82  * is working, and answer questions such as "why are there so many
  83  * 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 that
  87  * change the size of a file (such operations can often be the
  88  * source of data corruption if applications aren't using file
  89  * locking properly).
  90  */
  91 enum 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 /*
 123  * NFS local caching servicing counters
 124  */
 125 enum nfs_stat_fscachecounters {
 126         NFSIOS_FSCACHE_PAGES_READ_OK,
 127         NFSIOS_FSCACHE_PAGES_READ_FAIL,
 128         NFSIOS_FSCACHE_PAGES_WRITTEN_OK,
 129         NFSIOS_FSCACHE_PAGES_WRITTEN_FAIL,
 130         NFSIOS_FSCACHE_PAGES_UNCACHED,
 131         __NFSIOS_FSCACHEMAX,
 132 };
 133
 134 #endif  /* _LINUX_NFS_IOSTAT */