1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * This file contains all the stubs needed when communicating with lockd. 4 * This level of indirection is necessary so we can run nfsd+lockd without 5 * requiring the nfs client to be compiled in/loaded, and vice versa. 6 * 7 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> 8 */ 9 10 #include <linux/file.h> 11 #include <linux/lockd/bind.h> 12 #include "nfsd.h" 13 #include "vfs.h" 14 15 #define NFSDDBG_FACILITY NFSDDBG_LOCKD 16 17 #ifdef CONFIG_LOCKD_V4 18 #define nlm_stale_fh nlm4_stale_fh 19 #define nlm_failed nlm4_failed 20 #else 21 #define nlm_stale_fh nlm_lck_denied_nolocks 22 #define nlm_failed nlm_lck_denied_nolocks 23 #endif 24 /* 25 * Note: we hold the dentry use count while the file is open. 26 */ 27 static __be32 28 nlm_fopen(struct svc_rqst *rqstp, struct nfs_fh *f, struct file **filp, 29 int mode) 30 { 31 __be32 nfserr; 32 int access; 33 struct svc_fh fh; 34 35 /* must initialize before using! but maxsize doesn't matter */ 36 fh_init(&fh,0); 37 fh.fh_handle.fh_size = f->size; 38 memcpy(&fh.fh_handle.fh_raw, f->data, f->size); 39 fh.fh_export = NULL; 40 41 /* 42 * Allow BYPASS_GSS as some client implementations use AUTH_SYS 43 * for NLM even when GSS is used for NFS. 44 * Allow OWNER_OVERRIDE as permission might have been changed 45 * after the file was opened. 46 * Pass MAY_NLM so that authentication can be completely bypassed 47 * if NFSEXP_NOAUTHNLM is set. Some older clients use AUTH_NULL 48 * for NLM requests. 49 */ 50 access = (mode == O_WRONLY) ? NFSD_MAY_WRITE : NFSD_MAY_READ; 51 access |= NFSD_MAY_NLM | NFSD_MAY_OWNER_OVERRIDE | NFSD_MAY_BYPASS_GSS; 52 nfserr = nfsd_open(rqstp, &fh, S_IFREG, access, filp); 53 fh_put(&fh); 54 /* We return nlm error codes as nlm doesn't know 55 * about nfsd, but nfsd does know about nlm.. 56 */ 57 switch (nfserr) { 58 case nfs_ok: 59 return 0; 60 case nfserr_jukebox: 61 /* this error can indicate a presence of a conflicting 62 * delegation to an NLM lock request. Options are: 63 * (1) For now, drop this request and make the client 64 * retry. When delegation is returned, client's lock retry 65 * will complete. 66 * (2) NLM4_DENIED as per "spec" signals to the client 67 * that the lock is unavailable now but client can retry. 68 * Linux client implementation does not. It treats 69 * NLM4_DENIED same as NLM4_FAILED and errors the request. 70 * (3) For the future, treat this as blocked lock and try 71 * to callback when the delegation is returned but might 72 * not have a proper lock request to block on. 73 */ 74 return nlm_drop_reply; 75 case nfserr_stale: 76 return nlm_stale_fh; 77 default: 78 return nlm_failed; 79 } 80 } 81 82 static void 83 nlm_fclose(struct file *filp) 84 { 85 fput(filp); 86 } 87 88 static const struct nlmsvc_binding nfsd_nlm_ops = { 89 .fopen = nlm_fopen, /* open file for locking */ 90 .fclose = nlm_fclose, /* close file */ 91 }; 92 93 void 94 nfsd_lockd_init(void) 95 { 96 dprintk("nfsd: initializing lockd\n"); 97 nlmsvc_ops = &nfsd_nlm_ops; 98 } 99 100 void 101 nfsd_lockd_shutdown(void) 102 { 103 nlmsvc_ops = NULL; 104 } 105