1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
|
.\" Automatically generated by Pod::Man 2.25 (Pod::Simple 3.16)
.\"
.\" Standard preamble:
.\" ========================================================================
.de Sp \" Vertical space (when we can't use .PP)
.if t .sp .5v
.if n .sp
..
.de Vb \" Begin verbatim text
.ft CW
.nf
.ne \\$1
..
.de Ve \" End verbatim text
.ft R
.fi
..
.\" Set up some character translations and predefined strings. \*(-- will
.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
.\" double quote, and \*(R" will give a right double quote. \*(C+ will
.\" give a nicer C++. Capital omega is used to do unbreakable dashes and
.\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
.\" nothing in troff, for use with C<>.
.tr \(*W-
.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
.ie n \{\
. ds -- \(*W-
. ds PI pi
. if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
. if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
. ds L" ""
. ds R" ""
. ds C` ""
. ds C' ""
'br\}
.el\{\
. ds -- \|\(em\|
. ds PI \(*p
. ds L" ``
. ds R" ''
'br\}
.\"
.\" Escape single quotes in literal strings from groff's Unicode transform.
.ie \n(.g .ds Aq \(aq
.el .ds Aq '
.\"
.\" If the F register is turned on, we'll generate index entries on stderr for
.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
.\" entries marked with X<> in POD. Of course, you'll have to process the
.\" output yourself in some meaningful fashion.
.ie \nF \{\
. de IX
. tm Index:\\$1\t\\n%\t"\\$2"
..
. nr % 0
. rr F
.\}
.el \{\
. de IX
..
.\}
.\"
.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
.\" Fear. Run. Save yourself. No user-serviceable parts.
. \" fudge factors for nroff and troff
.if n \{\
. ds #H 0
. ds #V .8m
. ds #F .3m
. ds #[ \f1
. ds #] \fP
.\}
.if t \{\
. ds #H ((1u-(\\\\n(.fu%2u))*.13m)
. ds #V .6m
. ds #F 0
. ds #[ \&
. ds #] \&
.\}
. \" simple accents for nroff and troff
.if n \{\
. ds ' \&
. ds ` \&
. ds ^ \&
. ds , \&
. ds ~ ~
. ds /
.\}
.if t \{\
. ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
. ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
. ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
. ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
. ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
. ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
.\}
. \" troff and (daisy-wheel) nroff accents
.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
.ds ae a\h'-(\w'a'u*4/10)'e
.ds Ae A\h'-(\w'A'u*4/10)'E
. \" corrections for vroff
.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
. \" for low resolution devices (crt and lpr)
.if \n(.H>23 .if \n(.V>19 \
\{\
. ds : e
. ds 8 ss
. ds o a
. ds d- d\h'-1'\(ga
. ds D- D\h'-1'\(hy
. ds th \o'bp'
. ds Th \o'LP'
. ds ae ae
. ds Ae AE
.\}
.rm #[ #] #H #V #F C
.\" ========================================================================
.\"
.IX Title "NFSDCLTRACK 8"
.TH NFSDCLTRACK 8 "2012-10-24" "" ""
.\" For nroff, turn off justification. Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH "NAME"
nfsdcltrack \- NFSv4 Client Tracking Callout Program
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
nfsdcltrack [\-d] [\-f] [\-s stable storage dir] <command> <args...>
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
nfsdcltack is the NFSv4 client tracking callout program. It is not necessary
to install this daemon on machines that are not acting as NFSv4 servers.
.PP
When a network partition is combined with a server reboot, there are
edge conditions that can cause the server to grant lock reclaims when
other clients have taken conflicting locks in the interim. A more detailed
explanation of this issue is described in \s-1RFC\s0 3530, section 8.6.3.
.PP
In order to prevent these problems, the server must track a small amount
of per-client information on stable storage. This program provides the
userspace piece of that functionality. When the kernel needs to manipulate
the database that stores this info, it will execute this program to handle
it.
.SH "OPTIONS"
.IX Header "OPTIONS"
.IP "\fB\-d\fR, \fB\-\-debug\fR" 4
.IX Item "-d, --debug"
Enable debug level logging.
.IP "\fB\-f\fR, \fB\-\-foreground\fR" 4
.IX Item "-f, --foreground"
Log to stderr instead of syslog.
.IP "\fB\-s\fR \fIstoragedir\fR, \fB\-\-storagedir\fR=\fIstorage_dir\fR" 4
.IX Item "-s storagedir, --storagedir=storage_dir"
Directory where stable storage information should be kept. The default
value is \fI/var/lib/nfs/nfsdcltrack\fR.
.SH "COMMANDS"
.IX Header "COMMANDS"
nfsdcltrack requires a command for each invocation. Supported commands
are:
.IP "\fBinit\fR" 4
.IX Item "init"
Initialize the database. This command requires no argument.
.IP "\fBcreate\fR" 4
.IX Item "create"
Create a new client record (or update the timestamp on an existing one). This command requires a hex-encoded nfs_client_id4 as an argument.
.IP "\fBremove\fR" 4
.IX Item "remove"
Remove a client record from the database. This command requires a hex-encoded nfs_client_id4 as an argument.
.IP "\fBcheck\fR" 4
.IX Item "check"
Check to see if a nfs_client_id4 is allowed to reclaim. This command requires a hex-encoded nfs_client_id4 as an argument.
.IP "\fBgracedone\fR" 4
.IX Item "gracedone"
Remove any unreclaimed client records from the database. This command requires a epoch boot time as an argument.
.SH "LEGACY TRANSITION MECHANISM"
.IX Header "LEGACY TRANSITION MECHANISM"
The Linux kernel NFSv4 server has historically tracked this information
on stable storage by manipulating information on the filesystem
directly, in the directory to which \fI/proc/fs/nfsd/nfsv4recoverydir\fR
points. If the kernel passes the correct information, then nfsdcltrack
can use it to allow a seamless transition from the old client tracking
scheme to the new one.
.PP
On a \fBcheck\fR operation, if there is no record of the client in the
database, nfsdcltrack will look to see if the \fB\s-1NFSDCLTRACK_LEGACY_RECDIR\s0\fR
environment variable is set. If it is, then it will fetch that value and
see if a directory exists by that name. If it does, then the check
operation will succeed and the directory will be removed.
.PP
On a \fBgracedone\fR operation, nfsdcltrack will look to see if the
\&\fB\s-1NFSDCLTRACK_LEGACY_TOPDIR\s0\fR environment variable is set. If it is, then
it will attempt to clean out that directory prior to exiting.
.PP
Note that this transition is one-way. If the machine subsequently reboots
back into an older kernel that does not support the nfsdcltrack upcall
then the clients will not be able to recover their state.
.SH "NOTES"
.IX Header "NOTES"
This program requires a kernel that supports the nfsdcltrack usermodehelper
upcall. This support was first added to mainline kernels in 3.8.
.SH "AUTHORS"
.IX Header "AUTHORS"
nfsdcltrack was developed by Jeff Layton <jlayton@redhat.com>.
|
