1 /* SPDX-License-Identifier: GPL-2.0 */ 1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* 2 /*
3 * User-space visible declarations for NFS cl 3 * User-space visible declarations for NFS client per-mount
4 * point statistics 4 * point statistics
5 * 5 *
6 * Copyright (C) 2005, 2006 Chuck Lever <cel@ 6 * Copyright (C) 2005, 2006 Chuck Lever <cel@netapp.com>
7 * 7 *
8 * NFS client per-mount statistics provide in 8 * NFS client per-mount statistics provide information about the
9 * health of the NFS client and the health of 9 * health of the NFS client and the health of each NFS mount point.
10 * Generally these are not for detailed probl 10 * Generally these are not for detailed problem diagnosis, but
11 * simply to indicate that there is a problem 11 * simply to indicate that there is a problem.
12 * 12 *
13 * These counters are not meant to be human-r 13 * These counters are not meant to be human-readable, but are meant
14 * to be integrated into system monitoring to 14 * to be integrated into system monitoring tools such as "sar" and
15 * "iostat". As such, the counters are sampl 15 * "iostat". As such, the counters are sampled by the tools over
16 * time, and are never zeroed after a file sy 16 * time, and are never zeroed after a file system is mounted.
17 * Moving averages can be computed by the too 17 * Moving averages can be computed by the tools by taking the
18 * difference between two instantaneous sampl 18 * difference between two instantaneous samples and dividing that
19 * by the time between the samples. 19 * by the time between the samples.
20 */ 20 */
21 21
22 #ifndef _LINUX_NFS_IOSTAT 22 #ifndef _LINUX_NFS_IOSTAT
23 #define _LINUX_NFS_IOSTAT 23 #define _LINUX_NFS_IOSTAT
24 24
25 #define NFS_IOSTAT_VERS "1.1" 25 #define NFS_IOSTAT_VERS "1.1"
26 26
27 /* 27 /*
28 * NFS byte counters 28 * NFS byte counters
29 * 29 *
30 * 1. SERVER - the number of payload bytes re 30 * 1. SERVER - the number of payload bytes read from or written
31 * to the server by the NFS client via an 31 * to the server by the NFS client via an NFS READ or WRITE
32 * request. 32 * request.
33 * 33 *
34 * 2. NORMAL - the number of bytes read or wr 34 * 2. NORMAL - the number of bytes read or written by applications
35 * via the read(2) and write(2) system cal 35 * via the read(2) and write(2) system call interfaces.
36 * 36 *
37 * 3. DIRECT - the number of bytes read or wr 37 * 3. DIRECT - the number of bytes read or written from files
38 * opened with the O_DIRECT flag. 38 * opened with the O_DIRECT flag.
39 * 39 *
40 * These counters give a view of the data thro 40 * These counters give a view of the data throughput into and out
41 * of the NFS client. Comparing the number of 41 * of the NFS client. Comparing the number of bytes requested by
42 * an application with the number of bytes the 42 * an application with the number of bytes the client requests from
43 * the server can provide an indication of cli 43 * the server can provide an indication of client efficiency
44 * (per-op, cache hits, etc). 44 * (per-op, cache hits, etc).
45 * 45 *
46 * These counters can also help characterize w 46 * These counters can also help characterize which access methods
47 * are in use. DIRECT by itself shows whether 47 * are in use. DIRECT by itself shows whether there is any O_DIRECT
48 * traffic. NORMAL + DIRECT shows how much da 48 * traffic. NORMAL + DIRECT shows how much data is going through
49 * the system call interface. A large amount 49 * the system call interface. A large amount of SERVER traffic
50 * without much NORMAL or DIRECT traffic shows 50 * without much NORMAL or DIRECT traffic shows that applications
51 * are using mapped files. 51 * are using mapped files.
52 * 52 *
53 * NFS page counters 53 * NFS page counters
54 * 54 *
55 * These count the number of pages read or wri 55 * These count the number of pages read or written via nfs_readpage(),
56 * nfs_readpages(), or their write equivalents 56 * nfs_readpages(), or their write equivalents.
57 * 57 *
58 * NB: When adding new byte counters, please i 58 * NB: When adding new byte counters, please include the measured
59 * units in the name of each byte counter to h 59 * units in the name of each byte counter to help users of this
60 * interface determine what exactly is being c 60 * interface determine what exactly is being counted.
61 */ 61 */
62 enum nfs_stat_bytecounters { 62 enum nfs_stat_bytecounters {
63 NFSIOS_NORMALREADBYTES = 0, 63 NFSIOS_NORMALREADBYTES = 0,
64 NFSIOS_NORMALWRITTENBYTES, 64 NFSIOS_NORMALWRITTENBYTES,
65 NFSIOS_DIRECTREADBYTES, 65 NFSIOS_DIRECTREADBYTES,
66 NFSIOS_DIRECTWRITTENBYTES, 66 NFSIOS_DIRECTWRITTENBYTES,
67 NFSIOS_SERVERREADBYTES, 67 NFSIOS_SERVERREADBYTES,
68 NFSIOS_SERVERWRITTENBYTES, 68 NFSIOS_SERVERWRITTENBYTES,
69 NFSIOS_READPAGES, 69 NFSIOS_READPAGES,
70 NFSIOS_WRITEPAGES, 70 NFSIOS_WRITEPAGES,
71 __NFSIOS_BYTESMAX, 71 __NFSIOS_BYTESMAX,
72 }; 72 };
73 73
74 /* 74 /*
75 * NFS event counters 75 * NFS event counters
76 * 76 *
77 * These counters provide a low-overhead way o 77 * These counters provide a low-overhead way of monitoring client
78 * activity without enabling NFS trace debuggi 78 * activity without enabling NFS trace debugging. The counters
79 * show the rate at which VFS requests are mad 79 * show the rate at which VFS requests are made, and how often the
80 * client invalidates its data and attribute c 80 * client invalidates its data and attribute caches. This allows
81 * system administrators to monitor such thing 81 * system administrators to monitor such things as how close-to-open
82 * is working, and answer questions such as "w 82 * is working, and answer questions such as "why are there so many
83 * GETATTR requests on the wire?" 83 * GETATTR requests on the wire?"
84 * 84 *
85 * They also count anamolous events such as sh 85 * They also count anamolous events such as short reads and writes,
86 * silly renames due to close-after-delete, an 86 * silly renames due to close-after-delete, and operations that
87 * change the size of a file (such operations 87 * change the size of a file (such operations can often be the
88 * source of data corruption if applications a 88 * source of data corruption if applications aren't using file
89 * locking properly). 89 * locking properly).
90 */ 90 */
91 enum nfs_stat_eventcounters { 91 enum nfs_stat_eventcounters {
92 NFSIOS_INODEREVALIDATE = 0, 92 NFSIOS_INODEREVALIDATE = 0,
93 NFSIOS_DENTRYREVALIDATE, 93 NFSIOS_DENTRYREVALIDATE,
94 NFSIOS_DATAINVALIDATE, 94 NFSIOS_DATAINVALIDATE,
95 NFSIOS_ATTRINVALIDATE, 95 NFSIOS_ATTRINVALIDATE,
96 NFSIOS_VFSOPEN, 96 NFSIOS_VFSOPEN,
97 NFSIOS_VFSLOOKUP, 97 NFSIOS_VFSLOOKUP,
98 NFSIOS_VFSACCESS, 98 NFSIOS_VFSACCESS,
99 NFSIOS_VFSUPDATEPAGE, 99 NFSIOS_VFSUPDATEPAGE,
100 NFSIOS_VFSREADPAGE, 100 NFSIOS_VFSREADPAGE,
101 NFSIOS_VFSREADPAGES, 101 NFSIOS_VFSREADPAGES,
102 NFSIOS_VFSWRITEPAGE, 102 NFSIOS_VFSWRITEPAGE,
103 NFSIOS_VFSWRITEPAGES, 103 NFSIOS_VFSWRITEPAGES,
104 NFSIOS_VFSGETDENTS, 104 NFSIOS_VFSGETDENTS,
105 NFSIOS_VFSSETATTR, 105 NFSIOS_VFSSETATTR,
106 NFSIOS_VFSFLUSH, 106 NFSIOS_VFSFLUSH,
107 NFSIOS_VFSFSYNC, 107 NFSIOS_VFSFSYNC,
108 NFSIOS_VFSLOCK, 108 NFSIOS_VFSLOCK,
109 NFSIOS_VFSRELEASE, 109 NFSIOS_VFSRELEASE,
110 NFSIOS_CONGESTIONWAIT, 110 NFSIOS_CONGESTIONWAIT,
111 NFSIOS_SETATTRTRUNC, 111 NFSIOS_SETATTRTRUNC,
112 NFSIOS_EXTENDWRITE, 112 NFSIOS_EXTENDWRITE,
113 NFSIOS_SILLYRENAME, 113 NFSIOS_SILLYRENAME,
114 NFSIOS_SHORTREAD, 114 NFSIOS_SHORTREAD,
115 NFSIOS_SHORTWRITE, 115 NFSIOS_SHORTWRITE,
116 NFSIOS_DELAY, 116 NFSIOS_DELAY,
117 NFSIOS_PNFS_READ, 117 NFSIOS_PNFS_READ,
118 NFSIOS_PNFS_WRITE, 118 NFSIOS_PNFS_WRITE,
119 __NFSIOS_COUNTSMAX, 119 __NFSIOS_COUNTSMAX,
120 }; 120 };
121 121
122 #endif /* _LINUX_NFS_IOSTAT */ 122 #endif /* _LINUX_NFS_IOSTAT */
123 123
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