107 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			107 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * linux/fs/lockd/svcshare.c
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 *
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 * Management of DOS shares.
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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/time.h>
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#include <linux/unistd.h>
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#include <linux/string.h>
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#include <linux/slab.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/lockd/lockd.h>
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#include <linux/lockd/share.h>
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static inline int
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nlm_cmp_owner(struct nlm_share *share, struct xdr_netobj *oh)
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{
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	return share->s_owner.len == oh->len
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	    && !memcmp(share->s_owner.data, oh->data, oh->len);
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}
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__be32
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nlmsvc_share_file(struct nlm_host *host, struct nlm_file *file,
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			struct nlm_args *argp)
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{
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	struct nlm_share	*share;
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	struct xdr_netobj	*oh = &argp->lock.oh;
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	u8			*ohdata;
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	for (share = file->f_shares; share; share = share->s_next) {
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		if (share->s_host == host && nlm_cmp_owner(share, oh))
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			goto update;
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		if ((argp->fsm_access & share->s_mode)
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		 || (argp->fsm_mode   & share->s_access ))
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			return nlm_lck_denied;
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	}
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	share = kmalloc(sizeof(*share) + oh->len,
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						GFP_KERNEL);
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	if (share == NULL)
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		return nlm_lck_denied_nolocks;
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	/* Copy owner handle */
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	ohdata = (u8 *) (share + 1);
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	memcpy(ohdata, oh->data, oh->len);
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	share->s_file	    = file;
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	share->s_host       = host;
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	share->s_owner.data = ohdata;
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	share->s_owner.len  = oh->len;
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	share->s_next       = file->f_shares;
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	file->f_shares      = share;
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update:
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	share->s_access = argp->fsm_access;
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	share->s_mode   = argp->fsm_mode;
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	return nlm_granted;
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}
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/*
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 * Delete a share.
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 */
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__be32
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nlmsvc_unshare_file(struct nlm_host *host, struct nlm_file *file,
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			struct nlm_args *argp)
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{
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	struct nlm_share	*share, **shpp;
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	struct xdr_netobj	*oh = &argp->lock.oh;
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	for (shpp = &file->f_shares; (share = *shpp) != NULL;
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					shpp = &share->s_next) {
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		if (share->s_host == host && nlm_cmp_owner(share, oh)) {
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			*shpp = share->s_next;
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			kfree(share);
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			return nlm_granted;
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		}
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	}
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	/* X/Open spec says return success even if there was no
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	 * corresponding share. */
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	return nlm_granted;
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}
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/*
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 * Traverse all shares for a given file, and delete
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 * those owned by the given (type of) host
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 */
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void nlmsvc_traverse_shares(struct nlm_host *host, struct nlm_file *file,
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		nlm_host_match_fn_t match)
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{
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	struct nlm_share	*share, **shpp;
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	shpp = &file->f_shares;
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	while ((share = *shpp) !=  NULL) {
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		if (match(share->s_host, host)) {
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			*shpp = share->s_next;
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			kfree(share);
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			continue;
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		}
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		shpp = &share->s_next;
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	}
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}
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