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![Trond Myklebust](/assets/img/avatar_default.png)
The 'NFS error' NFSERR_OPNOTSUPP is not described by any of the official NFS related RFCs, but appears to have snuck into some older .x files for NFSv2. Either way, it is not in RFC1094, RFC1813 or any of the NFSv4 RFCs, so should not be returned by the knfsd server, and particularly not by the "LOOKUP" operation. Instead, let's return NFSERR_STALE, which is more appropriate if the filesystem encodes the filehandle as FILEID_INVALID. Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
791 lines
20 KiB
C
791 lines
20 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* NFS server file handle treatment.
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*
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* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
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* Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
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* Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999
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* ... and again Southern-Winter 2001 to support export_operations
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*/
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#include <linux/exportfs.h>
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#include <linux/sunrpc/svcauth_gss.h>
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#include "nfsd.h"
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#include "vfs.h"
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#include "auth.h"
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#include "trace.h"
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#define NFSDDBG_FACILITY NFSDDBG_FH
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/*
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* our acceptability function.
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* if NOSUBTREECHECK, accept anything
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* if not, require that we can walk up to exp->ex_dentry
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* doing some checks on the 'x' bits
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*/
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static int nfsd_acceptable(void *expv, struct dentry *dentry)
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{
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struct svc_export *exp = expv;
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int rv;
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struct dentry *tdentry;
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struct dentry *parent;
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if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
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return 1;
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tdentry = dget(dentry);
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while (tdentry != exp->ex_path.dentry && !IS_ROOT(tdentry)) {
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/* make sure parents give x permission to user */
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int err;
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parent = dget_parent(tdentry);
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err = inode_permission(&nop_mnt_idmap,
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d_inode(parent), MAY_EXEC);
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if (err < 0) {
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dput(parent);
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break;
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}
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dput(tdentry);
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tdentry = parent;
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}
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if (tdentry != exp->ex_path.dentry)
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dprintk("nfsd_acceptable failed at %p %pd\n", tdentry, tdentry);
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rv = (tdentry == exp->ex_path.dentry);
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dput(tdentry);
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return rv;
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}
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/* Type check. The correct error return for type mismatches does not seem to be
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* generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
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* comment in the NFSv3 spec says this is incorrect (implementation notes for
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* the write call).
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*/
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static inline __be32
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nfsd_mode_check(struct svc_rqst *rqstp, struct dentry *dentry,
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umode_t requested)
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{
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umode_t mode = d_inode(dentry)->i_mode & S_IFMT;
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if (requested == 0) /* the caller doesn't care */
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return nfs_ok;
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if (mode == requested) {
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if (mode == S_IFDIR && !d_can_lookup(dentry)) {
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WARN_ON_ONCE(1);
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return nfserr_notdir;
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}
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return nfs_ok;
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}
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/*
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* v4 has an error more specific than err_notdir which we should
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* return in preference to err_notdir:
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*/
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if (rqstp->rq_vers == 4 && mode == S_IFLNK)
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return nfserr_symlink;
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if (requested == S_IFDIR)
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return nfserr_notdir;
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if (mode == S_IFDIR)
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return nfserr_isdir;
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return nfserr_inval;
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}
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static bool nfsd_originating_port_ok(struct svc_rqst *rqstp, int flags)
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{
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if (flags & NFSEXP_INSECURE_PORT)
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return true;
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/* We don't require gss requests to use low ports: */
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if (rqstp->rq_cred.cr_flavor >= RPC_AUTH_GSS)
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return true;
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return test_bit(RQ_SECURE, &rqstp->rq_flags);
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}
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static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
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struct svc_export *exp)
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{
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int flags = nfsexp_flags(rqstp, exp);
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/* Check if the request originated from a secure port. */
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if (!nfsd_originating_port_ok(rqstp, flags)) {
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RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
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dprintk("nfsd: request from insecure port %s!\n",
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svc_print_addr(rqstp, buf, sizeof(buf)));
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return nfserr_perm;
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}
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/* Set user creds for this exportpoint */
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return nfserrno(nfsd_setuser(rqstp, exp));
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}
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static inline __be32 check_pseudo_root(struct svc_rqst *rqstp,
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struct dentry *dentry, struct svc_export *exp)
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{
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if (!(exp->ex_flags & NFSEXP_V4ROOT))
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return nfs_ok;
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/*
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* v2/v3 clients have no need for the V4ROOT export--they use
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* the mount protocl instead; also, further V4ROOT checks may be
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* in v4-specific code, in which case v2/v3 clients could bypass
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* them.
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*/
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if (!nfsd_v4client(rqstp))
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return nfserr_stale;
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/*
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* We're exposing only the directories and symlinks that have to be
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* traversed on the way to real exports:
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*/
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if (unlikely(!d_is_dir(dentry) &&
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!d_is_symlink(dentry)))
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return nfserr_stale;
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/*
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* A pseudoroot export gives permission to access only one
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* single directory; the kernel has to make another upcall
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* before granting access to anything else under it:
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*/
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if (unlikely(dentry != exp->ex_path.dentry))
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return nfserr_stale;
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return nfs_ok;
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}
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/*
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* Use the given filehandle to look up the corresponding export and
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* dentry. On success, the results are used to set fh_export and
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* fh_dentry.
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*/
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static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
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{
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struct knfsd_fh *fh = &fhp->fh_handle;
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struct fid *fid = NULL;
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struct svc_export *exp;
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struct dentry *dentry;
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int fileid_type;
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int data_left = fh->fh_size/4;
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int len;
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__be32 error;
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error = nfserr_stale;
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if (rqstp->rq_vers > 2)
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error = nfserr_badhandle;
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if (rqstp->rq_vers == 4 && fh->fh_size == 0)
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return nfserr_nofilehandle;
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if (fh->fh_version != 1)
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return error;
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if (--data_left < 0)
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return error;
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if (fh->fh_auth_type != 0)
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return error;
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len = key_len(fh->fh_fsid_type) / 4;
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if (len == 0)
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return error;
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if (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
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/* deprecated, convert to type 3 */
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len = key_len(FSID_ENCODE_DEV)/4;
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fh->fh_fsid_type = FSID_ENCODE_DEV;
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/*
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* struct knfsd_fh uses host-endian fields, which are
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* sometimes used to hold net-endian values. This
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* confuses sparse, so we must use __force here to
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* keep it from complaining.
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*/
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fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl((__force __be32)fh->fh_fsid[0]),
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ntohl((__force __be32)fh->fh_fsid[1])));
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fh->fh_fsid[1] = fh->fh_fsid[2];
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}
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data_left -= len;
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if (data_left < 0)
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return error;
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exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_fsid);
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fid = (struct fid *)(fh->fh_fsid + len);
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error = nfserr_stale;
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if (IS_ERR(exp)) {
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trace_nfsd_set_fh_dentry_badexport(rqstp, fhp, PTR_ERR(exp));
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if (PTR_ERR(exp) == -ENOENT)
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return error;
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return nfserrno(PTR_ERR(exp));
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}
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if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
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/* Elevate privileges so that the lack of 'r' or 'x'
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* permission on some parent directory will
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* not stop exportfs_decode_fh from being able
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* to reconnect a directory into the dentry cache.
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* The same problem can affect "SUBTREECHECK" exports,
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* but as nfsd_acceptable depends on correct
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* access control settings being in effect, we cannot
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* fix that case easily.
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*/
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struct cred *new = prepare_creds();
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if (!new) {
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error = nfserrno(-ENOMEM);
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goto out;
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}
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new->cap_effective =
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cap_raise_nfsd_set(new->cap_effective,
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new->cap_permitted);
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put_cred(override_creds(new));
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put_cred(new);
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} else {
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error = nfsd_setuser_and_check_port(rqstp, exp);
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if (error)
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goto out;
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}
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/*
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* Look up the dentry using the NFS file handle.
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*/
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error = nfserr_stale;
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if (rqstp->rq_vers > 2)
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error = nfserr_badhandle;
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fileid_type = fh->fh_fileid_type;
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if (fileid_type == FILEID_ROOT)
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dentry = dget(exp->ex_path.dentry);
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else {
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dentry = exportfs_decode_fh_raw(exp->ex_path.mnt, fid,
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data_left, fileid_type,
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nfsd_acceptable, exp);
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if (IS_ERR_OR_NULL(dentry)) {
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trace_nfsd_set_fh_dentry_badhandle(rqstp, fhp,
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dentry ? PTR_ERR(dentry) : -ESTALE);
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switch (PTR_ERR(dentry)) {
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case -ENOMEM:
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case -ETIMEDOUT:
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break;
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default:
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dentry = ERR_PTR(-ESTALE);
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}
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}
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}
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if (dentry == NULL)
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goto out;
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if (IS_ERR(dentry)) {
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if (PTR_ERR(dentry) != -EINVAL)
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error = nfserrno(PTR_ERR(dentry));
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goto out;
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}
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if (d_is_dir(dentry) &&
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(dentry->d_flags & DCACHE_DISCONNECTED)) {
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printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %pd2\n",
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dentry);
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}
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fhp->fh_dentry = dentry;
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fhp->fh_export = exp;
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switch (rqstp->rq_vers) {
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case 4:
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if (dentry->d_sb->s_export_op->flags & EXPORT_OP_NOATOMIC_ATTR)
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fhp->fh_no_atomic_attr = true;
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break;
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case 3:
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if (dentry->d_sb->s_export_op->flags & EXPORT_OP_NOWCC)
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fhp->fh_no_wcc = true;
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break;
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case 2:
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fhp->fh_no_wcc = true;
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}
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return 0;
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out:
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exp_put(exp);
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return error;
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}
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/**
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* fh_verify - filehandle lookup and access checking
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* @rqstp: pointer to current rpc request
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* @fhp: filehandle to be verified
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* @type: expected type of object pointed to by filehandle
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* @access: type of access needed to object
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*
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* Look up a dentry from the on-the-wire filehandle, check the client's
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* access to the export, and set the current task's credentials.
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*
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* Regardless of success or failure of fh_verify(), fh_put() should be
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* called on @fhp when the caller is finished with the filehandle.
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*
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* fh_verify() may be called multiple times on a given filehandle, for
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* example, when processing an NFSv4 compound. The first call will look
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* up a dentry using the on-the-wire filehandle. Subsequent calls will
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* skip the lookup and just perform the other checks and possibly change
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* the current task's credentials.
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*
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* @type specifies the type of object expected using one of the S_IF*
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* constants defined in include/linux/stat.h. The caller may use zero
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* to indicate that it doesn't care, or a negative integer to indicate
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* that it expects something not of the given type.
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*
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* @access is formed from the NFSD_MAY_* constants defined in
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* fs/nfsd/vfs.h.
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*/
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__be32
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fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int access)
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{
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struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
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struct svc_export *exp = NULL;
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struct dentry *dentry;
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__be32 error;
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if (!fhp->fh_dentry) {
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error = nfsd_set_fh_dentry(rqstp, fhp);
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if (error)
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goto out;
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}
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dentry = fhp->fh_dentry;
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exp = fhp->fh_export;
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trace_nfsd_fh_verify(rqstp, fhp, type, access);
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/*
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* We still have to do all these permission checks, even when
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* fh_dentry is already set:
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* - fh_verify may be called multiple times with different
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* "access" arguments (e.g. nfsd_proc_create calls
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* fh_verify(...,NFSD_MAY_EXEC) first, then later (in
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* nfsd_create) calls fh_verify(...,NFSD_MAY_CREATE).
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* - in the NFSv4 case, the filehandle may have been filled
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* in by fh_compose, and given a dentry, but further
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* compound operations performed with that filehandle
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* still need permissions checks. In the worst case, a
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* mountpoint crossing may have changed the export
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* options, and we may now need to use a different uid
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* (for example, if different id-squashing options are in
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* effect on the new filesystem).
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*/
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error = check_pseudo_root(rqstp, dentry, exp);
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if (error)
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goto out;
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error = nfsd_setuser_and_check_port(rqstp, exp);
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if (error)
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goto out;
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error = nfsd_mode_check(rqstp, dentry, type);
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if (error)
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goto out;
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/*
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* pseudoflavor restrictions are not enforced on NLM,
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* which clients virtually always use auth_sys for,
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* even while using RPCSEC_GSS for NFS.
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*/
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if (access & NFSD_MAY_LOCK || access & NFSD_MAY_BYPASS_GSS)
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goto skip_pseudoflavor_check;
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/*
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* Clients may expect to be able to use auth_sys during mount,
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* even if they use gss for everything else; see section 2.3.2
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* of rfc 2623.
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*/
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if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
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&& exp->ex_path.dentry == dentry)
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goto skip_pseudoflavor_check;
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error = check_nfsd_access(exp, rqstp);
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if (error)
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goto out;
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skip_pseudoflavor_check:
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/* Finally, check access permissions. */
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error = nfsd_permission(rqstp, exp, dentry, access);
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out:
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trace_nfsd_fh_verify_err(rqstp, fhp, type, access, error);
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if (error == nfserr_stale)
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nfsd_stats_fh_stale_inc(nn, exp);
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return error;
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}
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/*
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* Compose a file handle for an NFS reply.
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*
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* Note that when first composed, the dentry may not yet have
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* an inode. In this case a call to fh_update should be made
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* before the fh goes out on the wire ...
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*/
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static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
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struct dentry *dentry)
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{
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if (dentry != exp->ex_path.dentry) {
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struct fid *fid = (struct fid *)
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(fhp->fh_handle.fh_fsid + fhp->fh_handle.fh_size/4 - 1);
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int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
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int fh_flags = (exp->ex_flags & NFSEXP_NOSUBTREECHECK) ? 0 :
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EXPORT_FH_CONNECTABLE;
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int fileid_type =
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exportfs_encode_fh(dentry, fid, &maxsize, fh_flags);
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fhp->fh_handle.fh_fileid_type =
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fileid_type > 0 ? fileid_type : FILEID_INVALID;
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fhp->fh_handle.fh_size += maxsize * 4;
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} else {
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fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
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}
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}
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static bool is_root_export(struct svc_export *exp)
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{
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return exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root;
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}
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static struct super_block *exp_sb(struct svc_export *exp)
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{
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return exp->ex_path.dentry->d_sb;
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}
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static bool fsid_type_ok_for_exp(u8 fsid_type, struct svc_export *exp)
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{
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switch (fsid_type) {
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case FSID_DEV:
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if (!old_valid_dev(exp_sb(exp)->s_dev))
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return false;
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fallthrough;
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case FSID_MAJOR_MINOR:
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case FSID_ENCODE_DEV:
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return exp_sb(exp)->s_type->fs_flags & FS_REQUIRES_DEV;
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case FSID_NUM:
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return exp->ex_flags & NFSEXP_FSID;
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case FSID_UUID8:
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case FSID_UUID16:
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if (!is_root_export(exp))
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return false;
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fallthrough;
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case FSID_UUID4_INUM:
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case FSID_UUID16_INUM:
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return exp->ex_uuid != NULL;
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}
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return true;
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}
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static void set_version_and_fsid_type(struct svc_fh *fhp, struct svc_export *exp, struct svc_fh *ref_fh)
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{
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u8 version;
|
|
u8 fsid_type;
|
|
retry:
|
|
version = 1;
|
|
if (ref_fh && ref_fh->fh_export == exp) {
|
|
version = ref_fh->fh_handle.fh_version;
|
|
fsid_type = ref_fh->fh_handle.fh_fsid_type;
|
|
|
|
ref_fh = NULL;
|
|
|
|
switch (version) {
|
|
case 0xca:
|
|
fsid_type = FSID_DEV;
|
|
break;
|
|
case 1:
|
|
break;
|
|
default:
|
|
goto retry;
|
|
}
|
|
|
|
/*
|
|
* As the fsid -> filesystem mapping was guided by
|
|
* user-space, there is no guarantee that the filesystem
|
|
* actually supports that fsid type. If it doesn't we
|
|
* loop around again without ref_fh set.
|
|
*/
|
|
if (!fsid_type_ok_for_exp(fsid_type, exp))
|
|
goto retry;
|
|
} else if (exp->ex_flags & NFSEXP_FSID) {
|
|
fsid_type = FSID_NUM;
|
|
} else if (exp->ex_uuid) {
|
|
if (fhp->fh_maxsize >= 64) {
|
|
if (is_root_export(exp))
|
|
fsid_type = FSID_UUID16;
|
|
else
|
|
fsid_type = FSID_UUID16_INUM;
|
|
} else {
|
|
if (is_root_export(exp))
|
|
fsid_type = FSID_UUID8;
|
|
else
|
|
fsid_type = FSID_UUID4_INUM;
|
|
}
|
|
} else if (!old_valid_dev(exp_sb(exp)->s_dev))
|
|
/* for newer device numbers, we must use a newer fsid format */
|
|
fsid_type = FSID_ENCODE_DEV;
|
|
else
|
|
fsid_type = FSID_DEV;
|
|
fhp->fh_handle.fh_version = version;
|
|
if (version)
|
|
fhp->fh_handle.fh_fsid_type = fsid_type;
|
|
}
|
|
|
|
__be32
|
|
fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
|
|
struct svc_fh *ref_fh)
|
|
{
|
|
/* ref_fh is a reference file handle.
|
|
* if it is non-null and for the same filesystem, then we should compose
|
|
* a filehandle which is of the same version, where possible.
|
|
*/
|
|
|
|
struct inode * inode = d_inode(dentry);
|
|
dev_t ex_dev = exp_sb(exp)->s_dev;
|
|
|
|
dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %pd2, ino=%ld)\n",
|
|
MAJOR(ex_dev), MINOR(ex_dev),
|
|
(long) d_inode(exp->ex_path.dentry)->i_ino,
|
|
dentry,
|
|
(inode ? inode->i_ino : 0));
|
|
|
|
/* Choose filehandle version and fsid type based on
|
|
* the reference filehandle (if it is in the same export)
|
|
* or the export options.
|
|
*/
|
|
set_version_and_fsid_type(fhp, exp, ref_fh);
|
|
|
|
/* If we have a ref_fh, then copy the fh_no_wcc setting from it. */
|
|
fhp->fh_no_wcc = ref_fh ? ref_fh->fh_no_wcc : false;
|
|
|
|
if (ref_fh == fhp)
|
|
fh_put(ref_fh);
|
|
|
|
if (fhp->fh_dentry) {
|
|
printk(KERN_ERR "fh_compose: fh %pd2 not initialized!\n",
|
|
dentry);
|
|
}
|
|
if (fhp->fh_maxsize < NFS_FHSIZE)
|
|
printk(KERN_ERR "fh_compose: called with maxsize %d! %pd2\n",
|
|
fhp->fh_maxsize,
|
|
dentry);
|
|
|
|
fhp->fh_dentry = dget(dentry); /* our internal copy */
|
|
fhp->fh_export = exp_get(exp);
|
|
|
|
fhp->fh_handle.fh_size =
|
|
key_len(fhp->fh_handle.fh_fsid_type) + 4;
|
|
fhp->fh_handle.fh_auth_type = 0;
|
|
|
|
mk_fsid(fhp->fh_handle.fh_fsid_type,
|
|
fhp->fh_handle.fh_fsid,
|
|
ex_dev,
|
|
d_inode(exp->ex_path.dentry)->i_ino,
|
|
exp->ex_fsid, exp->ex_uuid);
|
|
|
|
if (inode)
|
|
_fh_update(fhp, exp, dentry);
|
|
if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID) {
|
|
fh_put(fhp);
|
|
return nfserr_stale;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Update file handle information after changing a dentry.
|
|
* This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
|
|
*/
|
|
__be32
|
|
fh_update(struct svc_fh *fhp)
|
|
{
|
|
struct dentry *dentry;
|
|
|
|
if (!fhp->fh_dentry)
|
|
goto out_bad;
|
|
|
|
dentry = fhp->fh_dentry;
|
|
if (d_really_is_negative(dentry))
|
|
goto out_negative;
|
|
if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
|
|
return 0;
|
|
|
|
_fh_update(fhp, fhp->fh_export, dentry);
|
|
if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID)
|
|
return nfserr_stale;
|
|
return 0;
|
|
out_bad:
|
|
printk(KERN_ERR "fh_update: fh not verified!\n");
|
|
return nfserr_serverfault;
|
|
out_negative:
|
|
printk(KERN_ERR "fh_update: %pd2 still negative!\n",
|
|
dentry);
|
|
return nfserr_serverfault;
|
|
}
|
|
|
|
/**
|
|
* fh_fill_pre_attrs - Fill in pre-op attributes
|
|
* @fhp: file handle to be updated
|
|
*
|
|
*/
|
|
__be32 __must_check fh_fill_pre_attrs(struct svc_fh *fhp)
|
|
{
|
|
bool v4 = (fhp->fh_maxsize == NFS4_FHSIZE);
|
|
struct inode *inode;
|
|
struct kstat stat;
|
|
__be32 err;
|
|
|
|
if (fhp->fh_no_wcc || fhp->fh_pre_saved)
|
|
return nfs_ok;
|
|
|
|
inode = d_inode(fhp->fh_dentry);
|
|
err = fh_getattr(fhp, &stat);
|
|
if (err)
|
|
return err;
|
|
|
|
if (v4)
|
|
fhp->fh_pre_change = nfsd4_change_attribute(&stat, inode);
|
|
|
|
fhp->fh_pre_mtime = stat.mtime;
|
|
fhp->fh_pre_ctime = stat.ctime;
|
|
fhp->fh_pre_size = stat.size;
|
|
fhp->fh_pre_saved = true;
|
|
return nfs_ok;
|
|
}
|
|
|
|
/**
|
|
* fh_fill_post_attrs - Fill in post-op attributes
|
|
* @fhp: file handle to be updated
|
|
*
|
|
*/
|
|
__be32 fh_fill_post_attrs(struct svc_fh *fhp)
|
|
{
|
|
bool v4 = (fhp->fh_maxsize == NFS4_FHSIZE);
|
|
struct inode *inode = d_inode(fhp->fh_dentry);
|
|
__be32 err;
|
|
|
|
if (fhp->fh_no_wcc)
|
|
return nfs_ok;
|
|
|
|
if (fhp->fh_post_saved)
|
|
printk("nfsd: inode locked twice during operation.\n");
|
|
|
|
err = fh_getattr(fhp, &fhp->fh_post_attr);
|
|
if (err)
|
|
return err;
|
|
|
|
fhp->fh_post_saved = true;
|
|
if (v4)
|
|
fhp->fh_post_change =
|
|
nfsd4_change_attribute(&fhp->fh_post_attr, inode);
|
|
return nfs_ok;
|
|
}
|
|
|
|
/**
|
|
* fh_fill_both_attrs - Fill pre-op and post-op attributes
|
|
* @fhp: file handle to be updated
|
|
*
|
|
* This is used when the directory wasn't changed, but wcc attributes
|
|
* are needed anyway.
|
|
*/
|
|
__be32 __must_check fh_fill_both_attrs(struct svc_fh *fhp)
|
|
{
|
|
__be32 err;
|
|
|
|
err = fh_fill_post_attrs(fhp);
|
|
if (err)
|
|
return err;
|
|
|
|
fhp->fh_pre_change = fhp->fh_post_change;
|
|
fhp->fh_pre_mtime = fhp->fh_post_attr.mtime;
|
|
fhp->fh_pre_ctime = fhp->fh_post_attr.ctime;
|
|
fhp->fh_pre_size = fhp->fh_post_attr.size;
|
|
fhp->fh_pre_saved = true;
|
|
return nfs_ok;
|
|
}
|
|
|
|
/*
|
|
* Release a file handle.
|
|
*/
|
|
void
|
|
fh_put(struct svc_fh *fhp)
|
|
{
|
|
struct dentry * dentry = fhp->fh_dentry;
|
|
struct svc_export * exp = fhp->fh_export;
|
|
if (dentry) {
|
|
fhp->fh_dentry = NULL;
|
|
dput(dentry);
|
|
fh_clear_pre_post_attrs(fhp);
|
|
}
|
|
fh_drop_write(fhp);
|
|
if (exp) {
|
|
exp_put(exp);
|
|
fhp->fh_export = NULL;
|
|
}
|
|
fhp->fh_no_wcc = false;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Shorthand for dprintk()'s
|
|
*/
|
|
char * SVCFH_fmt(struct svc_fh *fhp)
|
|
{
|
|
struct knfsd_fh *fh = &fhp->fh_handle;
|
|
static char buf[2+1+1+64*3+1];
|
|
|
|
if (fh->fh_size < 0 || fh->fh_size> 64)
|
|
return "bad-fh";
|
|
sprintf(buf, "%d: %*ph", fh->fh_size, fh->fh_size, fh->fh_raw);
|
|
return buf;
|
|
}
|
|
|
|
enum fsid_source fsid_source(const struct svc_fh *fhp)
|
|
{
|
|
if (fhp->fh_handle.fh_version != 1)
|
|
return FSIDSOURCE_DEV;
|
|
switch(fhp->fh_handle.fh_fsid_type) {
|
|
case FSID_DEV:
|
|
case FSID_ENCODE_DEV:
|
|
case FSID_MAJOR_MINOR:
|
|
if (exp_sb(fhp->fh_export)->s_type->fs_flags & FS_REQUIRES_DEV)
|
|
return FSIDSOURCE_DEV;
|
|
break;
|
|
case FSID_NUM:
|
|
if (fhp->fh_export->ex_flags & NFSEXP_FSID)
|
|
return FSIDSOURCE_FSID;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
/* either a UUID type filehandle, or the filehandle doesn't
|
|
* match the export.
|
|
*/
|
|
if (fhp->fh_export->ex_flags & NFSEXP_FSID)
|
|
return FSIDSOURCE_FSID;
|
|
if (fhp->fh_export->ex_uuid)
|
|
return FSIDSOURCE_UUID;
|
|
return FSIDSOURCE_DEV;
|
|
}
|
|
|
|
/*
|
|
* We could use i_version alone as the change attribute. However, i_version
|
|
* can go backwards on a regular file after an unclean shutdown. On its own
|
|
* that doesn't necessarily cause a problem, but if i_version goes backwards
|
|
* and then is incremented again it could reuse a value that was previously
|
|
* used before boot, and a client who queried the two values might incorrectly
|
|
* assume nothing changed.
|
|
*
|
|
* By using both ctime and the i_version counter we guarantee that as long as
|
|
* time doesn't go backwards we never reuse an old value. If the filesystem
|
|
* advertises STATX_ATTR_CHANGE_MONOTONIC, then this mitigation is not
|
|
* needed.
|
|
*
|
|
* We only need to do this for regular files as well. For directories, we
|
|
* assume that the new change attr is always logged to stable storage in some
|
|
* fashion before the results can be seen.
|
|
*/
|
|
u64 nfsd4_change_attribute(const struct kstat *stat, const struct inode *inode)
|
|
{
|
|
u64 chattr;
|
|
|
|
if (stat->result_mask & STATX_CHANGE_COOKIE) {
|
|
chattr = stat->change_cookie;
|
|
if (S_ISREG(inode->i_mode) &&
|
|
!(stat->attributes & STATX_ATTR_CHANGE_MONOTONIC)) {
|
|
chattr += (u64)stat->ctime.tv_sec << 30;
|
|
chattr += stat->ctime.tv_nsec;
|
|
}
|
|
} else {
|
|
chattr = time_to_chattr(&stat->ctime);
|
|
}
|
|
return chattr;
|
|
}
|