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898f944652
Since commit 9254c8ae9b ("nfsd: disallow file locking and delegations
for NFSv4 reexport"), file locking when reexporting an NFS mount via
NFSv4 is expressly prohibited by nfsd. Do the same in lockd:
Add a new nlmsvc_file_cannot_lock() helper that will test whether file
locking is allowed for a given file, and return nlm_lck_denied_nolocks
if it isn't.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Olga Kornievskaia <okorniev@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
114 lines
2.5 KiB
C
114 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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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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if (nlmsvc_file_cannot_lock(file))
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return nlm_lck_denied_nolocks;
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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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if (nlmsvc_file_cannot_lock(file))
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return nlm_lck_denied_nolocks;
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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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