nfsd-admin-interfaces.rst (1489B)
1================================== 2Administrative interfaces for nfsd 3================================== 4 5Note that normally these interfaces are used only by the utilities in 6nfs-utils. 7 8nfsd is controlled mainly by pseudofiles under the "nfsd" filesystem, 9which is normally mounted at /proc/fs/nfsd/. 10 11The server is always started by the first write of a nonzero value to 12nfsd/threads. 13 14Before doing that, NFSD can be told which sockets to listen on by 15writing to nfsd/portlist; that write may be: 16 17 - an ascii-encoded file descriptor, which should refer to a 18 bound (and listening, for tcp) socket, or 19 - "transportname port", where transportname is currently either 20 "udp", "tcp", or "rdma". 21 22If nfsd is started without doing any of these, then it will create one 23udp and one tcp listener at port 2049 (see nfsd_init_socks). 24 25On startup, nfsd and lockd grace periods start. nfsd is shut down by a write of 260 to nfsd/threads. All locks and state are thrown away at that point. 27 28Between startup and shutdown, the number of threads may be adjusted up 29or down by additional writes to nfsd/threads or by writes to 30nfsd/pool_threads. 31 32For more detail about files under nfsd/ and what they control, see 33fs/nfsd/nfsctl.c; most of them have detailed comments. 34 35Implementation notes 36==================== 37 38Note that the rpc server requires the caller to serialize addition and 39removal of listening sockets, and startup and shutdown of the server. 40For nfsd this is done using nfsd_mutex.