From 262a09823bb07c6aafb6c1d312cde613d0b90c85 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Fri, 12 Dec 2008 16:57:35 -0500 Subject: [PATCH] NFSD: Add documenting comments for nfsctl interface Document the NFSD sysctl interface laid out in fs/nfsd/nfsctl.c. Signed-off-by: Chuck Lever Signed-off-by: J. Bruce Fields --- fs/nfsd/nfsctl.c | 453 +++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 437 insertions(+), 16 deletions(-) diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 856b8646a480..3d93b2064ce5 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -175,10 +175,24 @@ static const struct file_operations exports_operations = { /*----------------------------------------------------------------------------*/ /* * payload - write methods - * If the method has a response, the response should be put in buf, - * and the length returned. Otherwise return 0 or and -error. */ +/** + * write_svc - Start kernel's NFSD server + * + * Deprecated. /proc/fs/nfsd/threads is preferred. + * Function remains to support old versions of nfs-utils. + * + * Input: + * buf: struct nfsctl_svc + * svc_port: port number of this + * server's listener + * svc_nthreads: number of threads to start + * size: size in bytes of passed in nfsctl_svc + * Output: + * On success: returns zero + * On error: return code is negative errno value + */ static ssize_t write_svc(struct file *file, char *buf, size_t size) { struct nfsctl_svc *data; @@ -188,6 +202,30 @@ static ssize_t write_svc(struct file *file, char *buf, size_t size) return nfsd_svc(data->svc_port, data->svc_nthreads); } +/** + * write_add - Add or modify client entry in auth unix cache + * + * Deprecated. /proc/net/rpc/auth.unix.ip is preferred. + * Function remains to support old versions of nfs-utils. + * + * Input: + * buf: struct nfsctl_client + * cl_ident: '\0'-terminated C string + * containing domain name + * of client + * cl_naddr: no. of items in cl_addrlist + * cl_addrlist: array of client addresses + * cl_fhkeytype: ignored + * cl_fhkeylen: ignored + * cl_fhkey: ignored + * size: size in bytes of passed in nfsctl_client + * Output: + * On success: returns zero + * On error: return code is negative errno value + * + * Note: Only AF_INET client addresses are passed in, since + * nfsctl_client.cl_addrlist contains only in_addr fields for addresses. + */ static ssize_t write_add(struct file *file, char *buf, size_t size) { struct nfsctl_client *data; @@ -197,6 +235,30 @@ static ssize_t write_add(struct file *file, char *buf, size_t size) return exp_addclient(data); } +/** + * write_del - Remove client from auth unix cache + * + * Deprecated. /proc/net/rpc/auth.unix.ip is preferred. + * Function remains to support old versions of nfs-utils. + * + * Input: + * buf: struct nfsctl_client + * cl_ident: '\0'-terminated C string + * containing domain name + * of client + * cl_naddr: ignored + * cl_addrlist: ignored + * cl_fhkeytype: ignored + * cl_fhkeylen: ignored + * cl_fhkey: ignored + * size: size in bytes of passed in nfsctl_client + * Output: + * On success: returns zero + * On error: return code is negative errno value + * + * Note: Only AF_INET client addresses are passed in, since + * nfsctl_client.cl_addrlist contains only in_addr fields for addresses. + */ static ssize_t write_del(struct file *file, char *buf, size_t size) { struct nfsctl_client *data; @@ -206,6 +268,33 @@ static ssize_t write_del(struct file *file, char *buf, size_t size) return exp_delclient(data); } +/** + * write_export - Export part or all of a local file system + * + * Deprecated. /proc/net/rpc/{nfsd.export,nfsd.fh} are preferred. + * Function remains to support old versions of nfs-utils. + * + * Input: + * buf: struct nfsctl_export + * ex_client: '\0'-terminated C string + * containing domain name + * of client allowed to access + * this export + * ex_path: '\0'-terminated C string + * containing pathname of + * directory in local file system + * ex_dev: fsid to use for this export + * ex_ino: ignored + * ex_flags: export flags for this export + * ex_anon_uid: UID to use for anonymous + * requests + * ex_anon_gid: GID to use for anonymous + * requests + * size: size in bytes of passed in nfsctl_export + * Output: + * On success: returns zero + * On error: return code is negative errno value + */ static ssize_t write_export(struct file *file, char *buf, size_t size) { struct nfsctl_export *data; @@ -215,6 +304,31 @@ static ssize_t write_export(struct file *file, char *buf, size_t size) return exp_export(data); } +/** + * write_unexport - Unexport a previously exported file system + * + * Deprecated. /proc/net/rpc/{nfsd.export,nfsd.fh} are preferred. + * Function remains to support old versions of nfs-utils. + * + * Input: + * buf: struct nfsctl_export + * ex_client: '\0'-terminated C string + * containing domain name + * of client no longer allowed + * to access this export + * ex_path: '\0'-terminated C string + * containing pathname of + * directory in local file system + * ex_dev: ignored + * ex_ino: ignored + * ex_flags: ignored + * ex_anon_uid: ignored + * ex_anon_gid: ignored + * size: size in bytes of passed in nfsctl_export + * Output: + * On success: returns zero + * On error: return code is negative errno value + */ static ssize_t write_unexport(struct file *file, char *buf, size_t size) { struct nfsctl_export *data; @@ -225,6 +339,30 @@ static ssize_t write_unexport(struct file *file, char *buf, size_t size) return exp_unexport(data); } +/** + * write_getfs - Get a variable-length NFS file handle by path + * + * Deprecated. /proc/fs/nfsd/filehandle is preferred. + * Function remains to support old versions of nfs-utils. + * + * Input: + * buf: struct nfsctl_fsparm + * gd_addr: socket address of client + * gd_path: '\0'-terminated C string + * containing pathname of + * directory in local file system + * gd_maxlen: maximum size of returned file + * handle + * size: size in bytes of passed in nfsctl_fsparm + * Output: + * On success: passed-in buffer filled with a knfsd_fh structure + * (a variable-length raw NFS file handle); + * return code is the size in bytes of the file handle + * On error: return code is negative errno value + * + * Note: Only AF_INET client addresses are passed in, since gd_addr + * is the same size as a struct sockaddr_in. + */ static ssize_t write_getfs(struct file *file, char *buf, size_t size) { struct nfsctl_fsparm *data; @@ -264,6 +402,29 @@ static ssize_t write_getfs(struct file *file, char *buf, size_t size) return err; } +/** + * write_getfd - Get a fixed-length NFS file handle by path (used by mountd) + * + * Deprecated. /proc/fs/nfsd/filehandle is preferred. + * Function remains to support old versions of nfs-utils. + * + * Input: + * buf: struct nfsctl_fdparm + * gd_addr: socket address of client + * gd_path: '\0'-terminated C string + * containing pathname of + * directory in local file system + * gd_version: fdparm structure version + * size: size in bytes of passed in nfsctl_fdparm + * Output: + * On success: passed-in buffer filled with nfsctl_res + * (a fixed-length raw NFS file handle); + * return code is the size in bytes of the file handle + * On error: return code is negative errno value + * + * Note: Only AF_INET client addresses are passed in, since gd_addr + * is the same size as a struct sockaddr_in. + */ static ssize_t write_getfd(struct file *file, char *buf, size_t size) { struct nfsctl_fdparm *data; @@ -308,6 +469,22 @@ static ssize_t write_getfd(struct file *file, char *buf, size_t size) return err; } +/** + * write_unlock_ip - Release all locks used by a client + * + * Experimental. + * + * Input: + * buf: '\n'-terminated C string containing a + * presentation format IPv4 address + * size: length of C string in @buf + * Output: + * On success: returns zero if all specified locks were released; + * returns one if one or more locks were not released + * On error: return code is negative errno value + * + * Note: Only AF_INET client addresses are passed in + */ static ssize_t write_unlock_ip(struct file *file, char *buf, size_t size) { struct sockaddr_in sin = { @@ -338,6 +515,20 @@ static ssize_t write_unlock_ip(struct file *file, char *buf, size_t size) return nlmsvc_unlock_all_by_ip((struct sockaddr *)&sin); } +/** + * write_unlock_fs - Release all locks on a local file system + * + * Experimental. + * + * Input: + * buf: '\n'-terminated C string containing the + * absolute pathname of a local file system + * size: length of C string in @buf + * Output: + * On success: returns zero if all specified locks were released; + * returns one if one or more locks were not released + * On error: return code is negative errno value + */ static ssize_t write_unlock_fs(struct file *file, char *buf, size_t size) { struct path path; @@ -359,21 +550,44 @@ static ssize_t write_unlock_fs(struct file *file, char *buf, size_t size) if (error) return error; + /* + * XXX: Needs better sanity checking. Otherwise we could end up + * releasing locks on the wrong file system. + * + * For example: + * 1. Does the path refer to a directory? + * 2. Is that directory a mount point, or + * 3. Is that directory the root of an exported file system? + */ error = nlmsvc_unlock_all_by_sb(path.mnt->mnt_sb); path_put(&path); return error; } +/** + * write_filehandle - Get a variable-length NFS file handle by path + * + * On input, the buffer contains a '\n'-terminated C string comprised of + * three alphanumeric words separated by whitespace. The string may + * contain escape sequences. + * + * Input: + * buf: + * domain: client domain name + * path: export pathname + * maxsize: numeric maximum size of + * @buf + * size: length of C string in @buf + * Output: + * On success: passed-in buffer filled with '\n'-terminated C + * string containing a ASCII hex text version + * of the NFS file handle; + * return code is the size in bytes of the string + * On error: return code is negative errno value + */ static ssize_t write_filehandle(struct file *file, char *buf, size_t size) { - /* request is: - * domain path maxsize - * response is - * filehandle - * - * qword quoting is used, so filehandle will be \x.... - */ char *dname, *path; int uninitialized_var(maxsize); char *mesg = buf; @@ -427,11 +641,36 @@ static ssize_t write_filehandle(struct file *file, char *buf, size_t size) return mesg - buf; } +/** + * write_threads - Start NFSD, or report the current number of running threads + * + * Input: + * buf: ignored + * size: zero + * Output: + * On success: passed-in buffer filled with '\n'-terminated C + * string numeric value representing the number of + * running NFSD threads; + * return code is the size in bytes of the string + * On error: return code is zero + * + * OR + * + * Input: + * buf: C string containing an unsigned + * integer value representing the + * number of NFSD threads to start + * size: non-zero length of C string in @buf + * Output: + * On success: NFS service is started; + * passed-in buffer filled with '\n'-terminated C + * string numeric value representing the number of + * running NFSD threads; + * return code is the size in bytes of the string + * On error: return code is zero or a negative errno value + */ static ssize_t write_threads(struct file *file, char *buf, size_t size) { - /* if size > 0, look for a number of threads and call nfsd_svc - * then write out number of threads as reply - */ char *mesg = buf; int rv; if (size > 0) { @@ -449,6 +688,28 @@ static ssize_t write_threads(struct file *file, char *buf, size_t size) return strlen(buf); } +/** + * write_pool_threads - Set or report the current number of threads per pool + * + * Input: + * buf: ignored + * size: zero + * + * OR + * + * Input: + * buf: C string containing whitespace- + * separated unsigned integer values + * representing the number of NFSD + * threads to start in each pool + * size: non-zero length of C string in @buf + * Output: + * On success: passed-in buffer filled with '\n'-terminated C + * string containing integer values representing the + * number of NFSD threads in each pool; + * return code is the size in bytes of the string + * On error: return code is zero or a negative errno value + */ static ssize_t write_pool_threads(struct file *file, char *buf, size_t size) { /* if size > 0, look for an array of number of threads per node @@ -519,10 +780,6 @@ out_free: static ssize_t __write_versions(struct file *file, char *buf, size_t size) { - /* - * Format: - * [-/+]vers [-/+]vers ... - */ char *mesg = buf; char *vers, sign; int len, num; @@ -580,6 +837,38 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t size) return len; } +/** + * write_versions - Set or report the available NFS protocol versions + * + * Input: + * buf: ignored + * size: zero + * Output: + * On success: passed-in buffer filled with '\n'-terminated C + * string containing positive or negative integer + * values representing the current status of each + * protocol version; + * return code is the size in bytes of the string + * On error: return code is zero or a negative errno value + * + * OR + * + * Input: + * buf: C string containing whitespace- + * separated positive or negative + * integer values representing NFS + * protocol versions to enable ("+n") + * or disable ("-n") + * size: non-zero length of C string in @buf + * Output: + * On success: status of zero or more protocol versions has + * been updated; passed-in buffer filled with + * '\n'-terminated C string containing positive + * or negative integer values representing the + * current status of each protocol version; + * return code is the size in bytes of the string + * On error: return code is zero or a negative errno value + */ static ssize_t write_versions(struct file *file, char *buf, size_t size) { ssize_t rv; @@ -689,6 +978,75 @@ static ssize_t __write_ports(struct file *file, char *buf, size_t size) return -EINVAL; } +/** + * write_ports - Pass a socket file descriptor or transport name to listen on + * + * Input: + * buf: ignored + * size: zero + * Output: + * On success: passed-in buffer filled with a '\n'-terminated C + * string containing a whitespace-separated list of + * named NFSD listeners; + * return code is the size in bytes of the string + * On error: return code is zero or a negative errno value + * + * OR + * + * Input: + * buf: C string containing an unsigned + * integer value representing a bound + * but unconnected socket that is to be + * used as an NFSD listener + * size: non-zero length of C string in @buf + * Output: + * On success: NFS service is started; + * passed-in buffer filled with a '\n'-terminated C + * string containing a unique alphanumeric name of + * the listener; + * return code is the size in bytes of the string + * On error: return code is a negative errno value + * + * OR + * + * Input: + * buf: C string containing a "-" followed + * by an integer value representing a + * previously passed in socket file + * descriptor + * size: non-zero length of C string in @buf + * Output: + * On success: NFS service no longer listens on that socket; + * passed-in buffer filled with a '\n'-terminated C + * string containing a unique name of the listener; + * return code is the size in bytes of the string + * On error: return code is a negative errno value + * + * OR + * + * Input: + * buf: C string containing a transport + * name and an unsigned integer value + * representing the port to listen on, + * separated by whitespace + * size: non-zero length of C string in @buf + * Output: + * On success: returns zero; NFS service is started + * On error: return code is a negative errno value + * + * OR + * + * Input: + * buf: C string containing a "-" followed + * by a transport name and an unsigned + * integer value representing the port + * to listen on, separated by whitespace + * size: non-zero length of C string in @buf + * Output: + * On success: returns zero; NFS service no longer listens + * on that transport + * On error: return code is a negative errno value + */ static ssize_t write_ports(struct file *file, char *buf, size_t size) { ssize_t rv; @@ -702,6 +1060,27 @@ static ssize_t write_ports(struct file *file, char *buf, size_t size) int nfsd_max_blksize; +/** + * write_maxblksize - Set or report the current NFS blksize + * + * Input: + * buf: ignored + * size: zero + * + * OR + * + * Input: + * buf: C string containing an unsigned + * integer value representing the new + * NFS blksize + * size: non-zero length of C string in @buf + * Output: + * On success: passed-in buffer filled with '\n'-terminated C string + * containing numeric value of the current NFS blksize + * setting; + * return code is the size in bytes of the string + * On error: return code is zero or a negative errno value + */ static ssize_t write_maxblksize(struct file *file, char *buf, size_t size) { char *mesg = buf; @@ -754,6 +1133,27 @@ static ssize_t __write_leasetime(struct file *file, char *buf, size_t size) return strlen(buf); } +/** + * write_leasetime - Set or report the current NFSv4 lease time + * + * Input: + * buf: ignored + * size: zero + * + * OR + * + * Input: + * buf: C string containing an unsigned + * integer value representing the new + * NFSv4 lease expiry time + * size: non-zero length of C string in @buf + * Output: + * On success: passed-in buffer filled with '\n'-terminated C + * string containing unsigned integer value of the + * current lease expiry time; + * return code is the size in bytes of the string + * On error: return code is zero or a negative errno value + */ static ssize_t write_leasetime(struct file *file, char *buf, size_t size) { ssize_t rv; @@ -790,6 +1190,27 @@ static ssize_t __write_recoverydir(struct file *file, char *buf, size_t size) return strlen(buf); } +/** + * write_recoverydir - Set or report the pathname of the recovery directory + * + * Input: + * buf: ignored + * size: zero + * + * OR + * + * Input: + * buf: C string containing the pathname + * of the directory on a local file + * system containing permanent NFSv4 + * recovery data + * size: non-zero length of C string in @buf + * Output: + * On success: passed-in buffer filled with '\n'-terminated C string + * containing the current recovery pathname setting; + * return code is the size in bytes of the string + * On error: return code is zero or a negative errno value + */ static ssize_t write_recoverydir(struct file *file, char *buf, size_t size) { ssize_t rv; -- 2.39.5