forked from luck/tmp_suning_uos_patched
af558e33be
Rewrite grace period code to unify management of grace period across lockd and nfsd. The current code has lockd and nfsd cooperate to compute a grace period which is satisfactory to them both, and then individually enforce it. This creates a slight race condition, since the enforcement is not coordinated. It's also more complicated than necessary. Here instead we have lockd and nfsd each inform common code when they enter the grace period, and when they're ready to leave the grace period, and allow normal locking only after both of them are ready to leave. We also expect the locks_start_grace()/locks_end_grace() interface here to be simpler to build on for future cluster/high-availability work, which may require (for example) putting individual filesystems into grace, or enforcing grace periods across multiple cluster nodes. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
87 lines
1.9 KiB
C
87 lines
1.9 KiB
C
/*
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* linux/fs/nfsd/lockd.c
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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/types.h>
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#include <linux/fs.h>
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#include <linux/file.h>
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#include <linux/mount.h>
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#include <linux/sunrpc/clnt.h>
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#include <linux/sunrpc/svc.h>
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#include <linux/nfsd/nfsd.h>
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#include <linux/lockd/bind.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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{
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__be32 nfserr;
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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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exp_readlock();
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nfserr = nfsd_open(rqstp, &fh, S_IFREG, NFSD_MAY_LOCK, filp);
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fh_put(&fh);
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rqstp->rq_client = NULL;
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exp_readunlock();
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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 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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