1 ================================== 1 ==================================
2 Administrative interfaces for nfsd 2 Administrative interfaces for nfsd
3 ================================== 3 ==================================
4 4
5 Note that normally these interfaces are used o 5 Note that normally these interfaces are used only by the utilities in
6 nfs-utils. 6 nfs-utils.
7 7
8 nfsd is controlled mainly by pseudofiles under 8 nfsd is controlled mainly by pseudofiles under the "nfsd" filesystem,
9 which is normally mounted at /proc/fs/nfsd/. 9 which is normally mounted at /proc/fs/nfsd/.
10 10
11 The server is always started by the first writ 11 The server is always started by the first write of a nonzero value to
12 nfsd/threads. 12 nfsd/threads.
13 13
14 Before doing that, NFSD can be told which sock 14 Before doing that, NFSD can be told which sockets to listen on by
15 writing to nfsd/portlist; that write may be: 15 writing to nfsd/portlist; that write may be:
16 16
17 - an ascii-encoded file descriptor, w 17 - an ascii-encoded file descriptor, which should refer to a
18 bound (and listening, for tcp) sock 18 bound (and listening, for tcp) socket, or
19 - "transportname port", where transpo 19 - "transportname port", where transportname is currently either
20 "udp", "tcp", or "rdma". 20 "udp", "tcp", or "rdma".
21 21
22 If nfsd is started without doing any of these, 22 If nfsd is started without doing any of these, then it will create one
23 udp and one tcp listener at port 2049 (see nfs 23 udp and one tcp listener at port 2049 (see nfsd_init_socks).
24 24
25 On startup, nfsd and lockd grace periods start 25 On startup, nfsd and lockd grace periods start. nfsd is shut down by a write of
26 0 to nfsd/threads. All locks and state are th 26 0 to nfsd/threads. All locks and state are thrown away at that point.
27 27
28 Between startup and shutdown, the number of th 28 Between startup and shutdown, the number of threads may be adjusted up
29 or down by additional writes to nfsd/threads o 29 or down by additional writes to nfsd/threads or by writes to
30 nfsd/pool_threads. 30 nfsd/pool_threads.
31 31
32 For more detail about files under nfsd/ and wh 32 For more detail about files under nfsd/ and what they control, see
33 fs/nfsd/nfsctl.c; most of them have detailed c 33 fs/nfsd/nfsctl.c; most of them have detailed comments.
34 34
35 Implementation notes 35 Implementation notes
36 ==================== 36 ====================
37 37
38 Note that the rpc server requires the caller t 38 Note that the rpc server requires the caller to serialize addition and
39 removal of listening sockets, and startup and 39 removal of listening sockets, and startup and shutdown of the server.
40 For nfsd this is done using nfsd_mutex. 40 For nfsd this is done using nfsd_mutex.
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