linux/fs/lockd/svcshare.c

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/*
* linux/fs/lockd/svcshare.c
*
* Management of DOS shares.
*
* Copyright (C) 1996 Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/time.h>
#include <linux/unistd.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/lockd/lockd.h>
#include <linux/lockd/share.h>
static inline int
nlm_cmp_owner(struct nlm_share *share, struct xdr_netobj *oh)
{
return share->s_owner.len == oh->len
&& !memcmp(share->s_owner.data, oh->data, oh->len);
}
u32
nlmsvc_share_file(struct nlm_host *host, struct nlm_file *file,
struct nlm_args *argp)
{
struct nlm_share *share;
struct xdr_netobj *oh = &argp->lock.oh;
u8 *ohdata;
for (share = file->f_shares; share; share = share->s_next) {
if (share->s_host == host && nlm_cmp_owner(share, oh))
goto update;
if ((argp->fsm_access & share->s_mode)
|| (argp->fsm_mode & share->s_access ))
return nlm_lck_denied;
}
share = (struct nlm_share *) kmalloc(sizeof(*share) + oh->len,
GFP_KERNEL);
if (share == NULL)
return nlm_lck_denied_nolocks;
/* Copy owner handle */
ohdata = (u8 *) (share + 1);
memcpy(ohdata, oh->data, oh->len);
share->s_file = file;
share->s_host = host;
share->s_owner.data = ohdata;
share->s_owner.len = oh->len;
share->s_next = file->f_shares;
file->f_shares = share;
update:
share->s_access = argp->fsm_access;
share->s_mode = argp->fsm_mode;
return nlm_granted;
}
/*
* Delete a share.
*/
u32
nlmsvc_unshare_file(struct nlm_host *host, struct nlm_file *file,
struct nlm_args *argp)
{
struct nlm_share *share, **shpp;
struct xdr_netobj *oh = &argp->lock.oh;
for (shpp = &file->f_shares; (share = *shpp) != 0; shpp = &share->s_next) {
if (share->s_host == host && nlm_cmp_owner(share, oh)) {
*shpp = share->s_next;
kfree(share);
return nlm_granted;
}
}
/* X/Open spec says return success even if there was no
* corresponding share. */
return nlm_granted;
}
/*
* Traverse all shares for a given file (and host).
* NLM_ACT_CHECK is handled by nlmsvc_inspect_file.
*/
int
nlmsvc_traverse_shares(struct nlm_host *host, struct nlm_file *file, int action)
{
struct nlm_share *share, **shpp;
shpp = &file->f_shares;
while ((share = *shpp) != NULL) {
if (action == NLM_ACT_MARK)
share->s_host->h_inuse = 1;
else if (action == NLM_ACT_UNLOCK) {
if (host == NULL || host == share->s_host) {
*shpp = share->s_next;
kfree(share);
continue;
}
}
shpp = &share->s_next;
}
return 0;
}