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| -rw-r--r-- | Documentation/filesystems/nfs/nfsd-admin-interfaces.txt | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/Documentation/filesystems/nfs/nfsd-admin-interfaces.txt b/Documentation/filesystems/nfs/nfsd-admin-interfaces.txt new file mode 100644 index 000000000000..56a96fb08a73 --- /dev/null +++ b/Documentation/filesystems/nfs/nfsd-admin-interfaces.txt @@ -0,0 +1,41 @@ +Administrative interfaces for nfsd +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Note that normally these interfaces are used only by the utilities in +nfs-utils. + +nfsd is controlled mainly by pseudofiles under the "nfsd" filesystem, +which is normally mounted at /proc/fs/nfsd/. + +The server is always started by the first write of a nonzero value to +nfsd/threads. + +Before doing that, NFSD can be told which sockets to listen on by +writing to nfsd/portlist; that write may be: + + - an ascii-encoded file descriptor, which should refer to a + bound (and listening, for tcp) socket, or + - "transportname port", where transportname is currently either + "udp", "tcp", or "rdma". + +If nfsd is started without doing any of these, then it will create one +udp and one tcp listener at port 2049 (see nfsd_init_socks). + +On startup, nfsd and lockd grace periods start. + +nfsd is shut down by a write of 0 to nfsd/threads. All locks and state +are thrown away at that point. + +Between startup and shutdown, the number of threads may be adjusted up +or down by additional writes to nfsd/threads or by writes to +nfsd/pool_threads. + +For more detail about files under nfsd/ and what they control, see +fs/nfsd/nfsctl.c; most of them have detailed comments. + +Implementation notes +^^^^^^^^^^^^^^^^^^^^ + +Note that the rpc server requires the caller to serialize addition and +removal of listening sockets, and startup and shutdown of the server. +For nfsd this is done using nfsd_mutex. |