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7f024fcd5c
We shouldn't really be using a read-only file descriptor to take a write lock. Most filesystems will put up with it. But NFS, for example, won't. Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
83 lines
1.8 KiB
C
83 lines
1.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* This file contains all the stubs needed when communicating with lockd.
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* This level of indirection is necessary so we can run nfsd+lockd without
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* requiring the nfs client to be compiled in/loaded, and vice versa.
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*
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* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
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*/
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#include <linux/file.h>
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#include <linux/lockd/bind.h>
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#include "nfsd.h"
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#include "vfs.h"
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#define NFSDDBG_FACILITY NFSDDBG_LOCKD
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#ifdef CONFIG_LOCKD_V4
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#define nlm_stale_fh nlm4_stale_fh
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#define nlm_failed nlm4_failed
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#else
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#define nlm_stale_fh nlm_lck_denied_nolocks
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#define nlm_failed nlm_lck_denied_nolocks
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#endif
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/*
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* Note: we hold the dentry use count while the file is open.
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*/
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static __be32
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nlm_fopen(struct svc_rqst *rqstp, struct nfs_fh *f, struct file **filp,
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int mode)
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{
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__be32 nfserr;
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int access;
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struct svc_fh fh;
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/* must initialize before using! but maxsize doesn't matter */
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fh_init(&fh,0);
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fh.fh_handle.fh_size = f->size;
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memcpy((char*)&fh.fh_handle.fh_base, f->data, f->size);
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fh.fh_export = NULL;
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access = (mode == O_WRONLY) ? NFSD_MAY_WRITE : NFSD_MAY_READ;
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access |= NFSD_MAY_LOCK;
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nfserr = nfsd_open(rqstp, &fh, S_IFREG, access, filp);
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fh_put(&fh);
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/* We return nlm error codes as nlm doesn't know
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* about nfsd, but nfsd does know about nlm..
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*/
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switch (nfserr) {
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case nfs_ok:
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return 0;
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case nfserr_dropit:
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return nlm_drop_reply;
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case nfserr_stale:
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return nlm_stale_fh;
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default:
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return nlm_failed;
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}
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}
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static void
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nlm_fclose(struct file *filp)
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{
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fput(filp);
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}
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static const struct nlmsvc_binding nfsd_nlm_ops = {
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.fopen = nlm_fopen, /* open file for locking */
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.fclose = nlm_fclose, /* close file */
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};
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void
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nfsd_lockd_init(void)
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{
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dprintk("nfsd: initializing lockd\n");
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nlmsvc_ops = &nfsd_nlm_ops;
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}
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void
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nfsd_lockd_shutdown(void)
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{
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nlmsvc_ops = NULL;
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}
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