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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 /*
  *  Server-side procedures for NFSv4.
  *
  *  Copyright (c) 2002 The Regents of the University of Michigan.
  *  All rights reserved.
  *
  *  Kendrick Smith <kmsmith@umich.edu>
  *  Andy Adamson   <andros@umich.edu>
  *
  *  Redistribution and use in source and binary forms, with or without
  *  modification, are permitted provided that the following conditions
  *  are met:
  *
  *  1. Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
  *     documentation and/or other materials provided with the distribution.
  *  3. Neither the name of the University nor the names of its
  *     contributors may be used to endorse or promote products derived
  *     from this software without specific prior written permission.
  *
  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #include <linux/fs_struct.h>
 #include <linux/file.h>
 #include <linux/falloc.h>
 #include <linux/slab.h>
 #include <linux/kthread.h>
 #include <linux/namei.h>
 
 #include <linux/sunrpc/addr.h>
 #include <linux/nfs_ssc.h>
 
 #include "idmap.h"
 #include "cache.h"
 #include "xdr4.h"
 #include "vfs.h"
 #include "current_stateid.h"
 #include "netns.h"
 #include "acl.h"
 #include "pnfs.h"
 #include "trace.h"
 
 static bool inter_copy_offload_enable;
 module_param(inter_copy_offload_enable, bool, 0644);
 MODULE_PARM_DESC(inter_copy_offload_enable,
          "Enable inter server to server copy offload. Default: false");
 
 #ifdef CONFIG_NFSD_V4_2_INTER_SSC
 static int nfsd4_ssc_umount_timeout = 900000;       /* default to 15 mins */
 module_param(nfsd4_ssc_umount_timeout, int, 0644);
 MODULE_PARM_DESC(nfsd4_ssc_umount_timeout,
         "idle msecs before unmount export from source server");
 #endif
 
 #define NFSDDBG_FACILITY        NFSDDBG_PROC
 
 static u32 nfsd_attrmask[] = {
     NFSD_WRITEABLE_ATTRS_WORD0,
     NFSD_WRITEABLE_ATTRS_WORD1,
     NFSD_WRITEABLE_ATTRS_WORD2
 };
 
 static u32 nfsd41_ex_attrmask[] = {
     NFSD_SUPPATTR_EXCLCREAT_WORD0,
     NFSD_SUPPATTR_EXCLCREAT_WORD1,
     NFSD_SUPPATTR_EXCLCREAT_WORD2
 };
 
 static __be32
 check_attr_support(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
            u32 *bmval, u32 *writable)
 {
     struct dentry *dentry = cstate->current_fh.fh_dentry;
     struct svc_export *exp = cstate->current_fh.fh_export;
 
     if (!nfsd_attrs_supported(cstate->minorversion, bmval))
         return nfserr_attrnotsupp;
     if ((bmval[0] & FATTR4_WORD0_ACL) && !IS_POSIXACL(d_inode(dentry)))
         return nfserr_attrnotsupp;
     if ((bmval[2] & FATTR4_WORD2_SECURITY_LABEL) &&
             !(exp->ex_flags & NFSEXP_SECURITY_LABEL))
         return nfserr_attrnotsupp;
     if (writable && !bmval_is_subset(bmval, writable))
         return nfserr_inval;
     if (writable && (bmval[2] & FATTR4_WORD2_MODE_UMASK) &&
             (bmval[1] & FATTR4_WORD1_MODE))
         return nfserr_inval;
     return nfs_ok;
 }
 
 static __be32
 nfsd4_check_open_attributes(struct svc_rqst *rqstp,
     struct nfsd4_compound_state *cstate, struct nfsd4_open *open)
 {
     __be32 status = nfs_ok;
 
     if (open->op_create == NFS4_OPEN_CREATE) {
         if (open->op_createmode == NFS4_CREATE_UNCHECKED
             || open->op_createmode == NFS4_CREATE_GUARDED)
             status = check_attr_support(rqstp, cstate,
                     open->op_bmval, nfsd_attrmask);
         else if (open->op_createmode == NFS4_CREATE_EXCLUSIVE4_1)
             status = check_attr_support(rqstp, cstate,
                     open->op_bmval, nfsd41_ex_attrmask);
     }
 
     return status;
 }
 
 static int
 is_create_with_attrs(struct nfsd4_open *open)
 {
     return open->op_create == NFS4_OPEN_CREATE
         && (open->op_createmode == NFS4_CREATE_UNCHECKED
             || open->op_createmode == NFS4_CREATE_GUARDED
             || open->op_createmode == NFS4_CREATE_EXCLUSIVE4_1);
 }
 
 static inline void
 fh_dup2(struct svc_fh *dst, struct svc_fh *src)
 {
     fh_put(dst);
     dget(src->fh_dentry);
     if (src->fh_export)
         exp_get(src->fh_export);
     *dst = *src;
 }
 
 static __be32
 do_open_permission(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open *open, int accmode)
 {
     __be32 status;
 
     if (open->op_truncate &&
         !(open->op_share_access & NFS4_SHARE_ACCESS_WRITE))
         return nfserr_inval;
 
     accmode |= NFSD_MAY_READ_IF_EXEC;
 
     if (open->op_share_access & NFS4_SHARE_ACCESS_READ)
         accmode |= NFSD_MAY_READ;
     if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE)
         accmode |= (NFSD_MAY_WRITE | NFSD_MAY_TRUNC);
     if (open->op_share_deny & NFS4_SHARE_DENY_READ)
         accmode |= NFSD_MAY_WRITE;
 
     status = fh_verify(rqstp, current_fh, S_IFREG, accmode);
 
     return status;
 }
 
 static __be32 nfsd_check_obj_isreg(struct svc_fh *fh)
 {
     umode_t mode = d_inode(fh->fh_dentry)->i_mode;
 
     if (S_ISREG(mode))
         return nfs_ok;
     if (S_ISDIR(mode))
         return nfserr_isdir;
     /*
      * Using err_symlink as our catch-all case may look odd; but
      * there's no other obvious error for this case in 4.0, and we
      * happen to know that it will cause the linux v4 client to do
      * the right thing on attempts to open something other than a
      * regular file.
      */
     return nfserr_symlink;
 }
 
 static void nfsd4_set_open_owner_reply_cache(struct nfsd4_compound_state *cstate, struct nfsd4_open *open, struct svc_fh *resfh)
 {
     if (nfsd4_has_session(cstate))
         return;
     fh_copy_shallow(&open->op_openowner->oo_owner.so_replay.rp_openfh,
             &resfh->fh_handle);
 }
 
 static inline bool nfsd4_create_is_exclusive(int createmode)
 {
     return createmode == NFS4_CREATE_EXCLUSIVE ||
         createmode == NFS4_CREATE_EXCLUSIVE4_1;
 }
 
 static __be32
 nfsd4_vfs_create(struct svc_fh *fhp, struct dentry *child,
          struct nfsd4_open *open)
 {
     struct file *filp;
     struct path path;
     int oflags;
 
     oflags = O_CREAT | O_LARGEFILE;
     switch (open->op_share_access & NFS4_SHARE_ACCESS_BOTH) {
     case NFS4_SHARE_ACCESS_WRITE:
         oflags |= O_WRONLY;
         break;
     case NFS4_SHARE_ACCESS_BOTH:
         oflags |= O_RDWR;
         break;
     default:
         oflags |= O_RDONLY;
     }
 
     path.mnt = fhp->fh_export->ex_path.mnt;
     path.dentry = child;
     filp = dentry_create(&path, oflags, open->op_iattr.ia_mode,
                  current_cred());
     if (IS_ERR(filp))
         return nfserrno(PTR_ERR(filp));
 
     open->op_filp = filp;
     return nfs_ok;
 }
 
 /*
  * Implement NFSv4's unchecked, guarded, and exclusive create
  * semantics for regular files. Open state for this new file is
  * subsequently fabricated in nfsd4_process_open2().
  *
  * Upon return, caller must release @fhp and @resfhp.
  */
 static __be32
 nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
           struct svc_fh *resfhp, struct nfsd4_open *open)
 {
     struct iattr *iap = &open->op_iattr;
     struct nfsd_attrs attrs = {
         .na_iattr   = iap,
         .na_seclabel    = &open->op_label,
     };
     struct dentry *parent, *child;
     __u32 v_mtime, v_atime;
     struct inode *inode;
     __be32 status;
     int host_err;
 
     if (isdotent(open->op_fname, open->op_fnamelen))
         return nfserr_exist;
     if (!(iap->ia_valid & ATTR_MODE))
         iap->ia_mode = 0;
 
     status = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
     if (status != nfs_ok)
         return status;
     parent = fhp->fh_dentry;
     inode = d_inode(parent);
 
     host_err = fh_want_write(fhp);
     if (host_err)
         return nfserrno(host_err);
 
     if (is_create_with_attrs(open))
         nfsd4_acl_to_attr(NF4REG, open->op_acl, &attrs);
 
     inode_lock_nested(inode, I_MUTEX_PARENT);
 
     child = lookup_one_len(open->op_fname, parent, open->op_fnamelen);
     if (IS_ERR(child)) {
         status = nfserrno(PTR_ERR(child));
         goto out;
     }
 
     if (d_really_is_negative(child)) {
         status = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
         if (status != nfs_ok)
             goto out;
     }
 
     status = fh_compose(resfhp, fhp->fh_export, child, fhp);
     if (status != nfs_ok)
         goto out;
 
     v_mtime = 0;
     v_atime = 0;
     if (nfsd4_create_is_exclusive(open->op_createmode)) {
         u32 *verifier = (u32 *)open->op_verf.data;
 
         /*
          * Solaris 7 gets confused (bugid 4218508) if these have
          * the high bit set, as do xfs filesystems without the
          * "bigtime" feature. So just clear the high bits. If this
          * is ever changed to use different attrs for storing the
          * verifier, then do_open_lookup() will also need to be
          * fixed accordingly.
          */
         v_mtime = verifier[0] & 0x7fffffff;
         v_atime = verifier[1] & 0x7fffffff;
     }
 
     if (d_really_is_positive(child)) {
         status = nfs_ok;
 
         /* NFSv4 protocol requires change attributes even though
          * no change happened.
          */
         fh_fill_both_attrs(fhp);
 
         switch (open->op_createmode) {
         case NFS4_CREATE_UNCHECKED:
             if (!d_is_reg(child))
                 break;
 
             /*
              * In NFSv4, we don't want to truncate the file
              * now. This would be wrong if the OPEN fails for
              * some other reason. Furthermore, if the size is
              * nonzero, we should ignore it according to spec!
              */
             open->op_truncate = (iap->ia_valid & ATTR_SIZE) &&
                         !iap->ia_size;
             break;
         case NFS4_CREATE_GUARDED:
             status = nfserr_exist;
             break;
         case NFS4_CREATE_EXCLUSIVE:
             if (d_inode(child)->i_mtime.tv_sec == v_mtime &&
                 d_inode(child)->i_atime.tv_sec == v_atime &&
                 d_inode(child)->i_size == 0) {
                 open->op_created = true;
                 break;      /* subtle */
             }
             status = nfserr_exist;
             break;
         case NFS4_CREATE_EXCLUSIVE4_1:
             if (d_inode(child)->i_mtime.tv_sec == v_mtime &&
                 d_inode(child)->i_atime.tv_sec == v_atime &&
                 d_inode(child)->i_size == 0) {
                 open->op_created = true;
                 goto set_attr;  /* subtle */
             }
             status = nfserr_exist;
         }
         goto out;
     }
 
     if (!IS_POSIXACL(inode))
         iap->ia_mode &= ~current_umask();
 
     fh_fill_pre_attrs(fhp);
     status = nfsd4_vfs_create(fhp, child, open);
     if (status != nfs_ok)
         goto out;
     open->op_created = true;
     fh_fill_post_attrs(fhp);
 
     /* A newly created file already has a file size of zero. */
     if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
         iap->ia_valid &= ~ATTR_SIZE;
     if (nfsd4_create_is_exclusive(open->op_createmode)) {
         iap->ia_valid = ATTR_MTIME | ATTR_ATIME |
                 ATTR_MTIME_SET|ATTR_ATIME_SET;
         iap->ia_mtime.tv_sec = v_mtime;
         iap->ia_atime.tv_sec = v_atime;
         iap->ia_mtime.tv_nsec = 0;
         iap->ia_atime.tv_nsec = 0;
     }
 
 set_attr:
     status = nfsd_create_setattr(rqstp, fhp, resfhp, &attrs);
 
     if (attrs.na_labelerr)
         open->op_bmval[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
     if (attrs.na_aclerr)
         open->op_bmval[0] &= ~FATTR4_WORD0_ACL;
 out:
     inode_unlock(inode);
     nfsd_attrs_free(&attrs);
     if (child && !IS_ERR(child))
         dput(child);
     fh_drop_write(fhp);
     return status;
 }
 
 static __be32
 do_open_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_open *open, struct svc_fh **resfh)
 {
     struct svc_fh *current_fh = &cstate->current_fh;
     int accmode;
     __be32 status;
 
     *resfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL);
     if (!*resfh)
         return nfserr_jukebox;
     fh_init(*resfh, NFS4_FHSIZE);
     open->op_truncate = false;
 
     if (open->op_create) {
         /* FIXME: check session persistence and pnfs flags.
          * The nfsv4.1 spec requires the following semantics:
          *
          * Persistent   | pNFS   | Server REQUIRED | Client Allowed
          * Reply Cache  | server |                 |
          * -------------+--------+-----------------+--------------------
          * no           | no     | EXCLUSIVE4_1    | EXCLUSIVE4_1
          *              |        |                 | (SHOULD)
          *              |        | and EXCLUSIVE4  | or EXCLUSIVE4
          *              |        |                 | (SHOULD NOT)
          * no           | yes    | EXCLUSIVE4_1    | EXCLUSIVE4_1
          * yes          | no     | GUARDED4        | GUARDED4
          * yes          | yes    | GUARDED4        | GUARDED4
          */
 
         current->fs->umask = open->op_umask;
         status = nfsd4_create_file(rqstp, current_fh, *resfh, open);
         current->fs->umask = 0;
 
         /*
          * Following rfc 3530 14.2.16, and rfc 5661 18.16.4
          * use the returned bitmask to indicate which attributes
          * we used to store the verifier:
          */
         if (nfsd4_create_is_exclusive(open->op_createmode) && status == 0)
             open->op_bmval[1] |= (FATTR4_WORD1_TIME_ACCESS |
                         FATTR4_WORD1_TIME_MODIFY);
     } else {
         status = nfsd_lookup(rqstp, current_fh,
                      open->op_fname, open->op_fnamelen, *resfh);
         if (!status)
             /* NFSv4 protocol requires change attributes even though
              * no change happened.
              */
             fh_fill_both_attrs(current_fh);
     }
     if (status)
         goto out;
     status = nfsd_check_obj_isreg(*resfh);
     if (status)
         goto out;
 
     nfsd4_set_open_owner_reply_cache(cstate, open, *resfh);
     accmode = NFSD_MAY_NOP;
     if (open->op_created ||
             open->op_claim_type == NFS4_OPEN_CLAIM_DELEGATE_CUR)
         accmode |= NFSD_MAY_OWNER_OVERRIDE;
     status = do_open_permission(rqstp, *resfh, open, accmode);
     set_change_info(&open->op_cinfo, current_fh);
 out:
     return status;
 }
 
 static __be32
 do_open_fhandle(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_open *open)
 {
     struct svc_fh *current_fh = &cstate->current_fh;
     __be32 status;
     int accmode = 0;
 
     /* We don't know the target directory, and therefore can not
     * set the change info
     */
 
     memset(&open->op_cinfo, 0, sizeof(struct nfsd4_change_info));
 
     nfsd4_set_open_owner_reply_cache(cstate, open, current_fh);
 
     open->op_truncate = (open->op_iattr.ia_valid & ATTR_SIZE) &&
         (open->op_iattr.ia_size == 0);
     /*
      * In the delegation case, the client is telling us about an
      * open that it *already* performed locally, some time ago.  We
      * should let it succeed now if possible.
      *
      * In the case of a CLAIM_FH open, on the other hand, the client
      * may be counting on us to enforce permissions (the Linux 4.1
      * client uses this for normal opens, for example).
      */
     if (open->op_claim_type == NFS4_OPEN_CLAIM_DELEG_CUR_FH)
         accmode = NFSD_MAY_OWNER_OVERRIDE;
 
     status = do_open_permission(rqstp, current_fh, open, accmode);
 
     return status;
 }
 
 static void
 copy_clientid(clientid_t *clid, struct nfsd4_session *session)
 {
     struct nfsd4_sessionid *sid =
             (struct nfsd4_sessionid *)session->se_sessionid.data;
 
     clid->cl_boot = sid->clientid.cl_boot;
     clid->cl_id = sid->clientid.cl_id;
 }
 
 static __be32
 nfsd4_open(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        union nfsd4_op_u *u)
 {
     struct nfsd4_open *open = &u->open;
     __be32 status;
     struct svc_fh *resfh = NULL;
     struct net *net = SVC_NET(rqstp);
     struct nfsd_net *nn = net_generic(net, nfsd_net_id);
     bool reclaim = false;
 
     dprintk("NFSD: nfsd4_open filename %.*s op_openowner %p\n",
         (int)open->op_fnamelen, open->op_fname,
         open->op_openowner);
 
     open->op_filp = NULL;
     open->op_rqstp = rqstp;
 
     /* This check required by spec. */
     if (open->op_create && open->op_claim_type != NFS4_OPEN_CLAIM_NULL)
         return nfserr_inval;
 
     open->op_created = false;
     /*
      * RFC5661 18.51.3
      * Before RECLAIM_COMPLETE done, server should deny new lock
      */
     if (nfsd4_has_session(cstate) &&
         !test_bit(NFSD4_CLIENT_RECLAIM_COMPLETE, &cstate->clp->cl_flags) &&
         open->op_claim_type != NFS4_OPEN_CLAIM_PREVIOUS)
         return nfserr_grace;
 
     if (nfsd4_has_session(cstate))
         copy_clientid(&open->op_clientid, cstate->session);
 
     /* check seqid for replay. set nfs4_owner */
     status = nfsd4_process_open1(cstate, open, nn);
     if (status == nfserr_replay_me) {
         struct nfs4_replay *rp = &open->op_openowner->oo_owner.so_replay;
         fh_put(&cstate->current_fh);
         fh_copy_shallow(&cstate->current_fh.fh_handle,
                 &rp->rp_openfh);
         status = fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_NOP);
         if (status)
             dprintk("nfsd4_open: replay failed"
                 " restoring previous filehandle\n");
         else
             status = nfserr_replay_me;
     }
     if (status)
         goto out;
     if (open->op_xdr_error) {
         status = open->op_xdr_error;
         goto out;
     }
 
     status = nfsd4_check_open_attributes(rqstp, cstate, open);
     if (status)
         goto out;
 
     /* Openowner is now set, so sequence id will get bumped.  Now we need
      * these checks before we do any creates: */
     status = nfserr_grace;
     if (opens_in_grace(net) && open->op_claim_type != NFS4_OPEN_CLAIM_PREVIOUS)
         goto out;
     status = nfserr_no_grace;
     if (!opens_in_grace(net) && open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS)
         goto out;
 
     switch (open->op_claim_type) {
     case NFS4_OPEN_CLAIM_DELEGATE_CUR:
     case NFS4_OPEN_CLAIM_NULL:
         status = do_open_lookup(rqstp, cstate, open, &resfh);
         if (status)
             goto out;
         break;
     case NFS4_OPEN_CLAIM_PREVIOUS:
         status = nfs4_check_open_reclaim(cstate->clp);
         if (status)
             goto out;
         open->op_openowner->oo_flags |= NFS4_OO_CONFIRMED;
         reclaim = true;
         fallthrough;
     case NFS4_OPEN_CLAIM_FH:
     case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
         status = do_open_fhandle(rqstp, cstate, open);
         if (status)
             goto out;
         resfh = &cstate->current_fh;
         break;
     case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
     case NFS4_OPEN_CLAIM_DELEGATE_PREV:
         status = nfserr_notsupp;
         goto out;
     default:
         status = nfserr_inval;
         goto out;
     }
 
     status = nfsd4_process_open2(rqstp, resfh, open);
     if (status && open->op_created)
         pr_warn("nfsd4_process_open2 failed to open newly-created file: status=%u\n",
             be32_to_cpu(status));
     if (reclaim && !status)
         nn->somebody_reclaimed = true;
 out:
     if (open->op_filp) {
         fput(open->op_filp);
         open->op_filp = NULL;
     }
     if (resfh && resfh != &cstate->current_fh) {
         fh_dup2(&cstate->current_fh, resfh);
         fh_put(resfh);
         kfree(resfh);
     }
     nfsd4_cleanup_open_state(cstate, open);
     nfsd4_bump_seqid(cstate, status);
     return status;
 }
 
 /*
  * OPEN is the only seqid-mutating operation whose decoding can fail
  * with a seqid-mutating error (specifically, decoding of user names in
  * the attributes).  Therefore we have to do some processing to look up
  * the stateowner so that we can bump the seqid.
  */
 static __be32 nfsd4_open_omfg(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_op *op)
 {
     struct nfsd4_open *open = &op->u.open;
 
     if (!seqid_mutating_err(ntohl(op->status)))
         return op->status;
     if (nfsd4_has_session(cstate))
         return op->status;
     open->op_xdr_error = op->status;
     return nfsd4_open(rqstp, cstate, &op->u);
 }
 
 /*
  * filehandle-manipulating ops.
  */
 static __be32
 nfsd4_getfh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         union nfsd4_op_u *u)
 {
     u->getfh = &cstate->current_fh;
     return nfs_ok;
 }
 
 static __be32
 nfsd4_putfh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         union nfsd4_op_u *u)
 {
     struct nfsd4_putfh *putfh = &u->putfh;
     __be32 ret;
 
     fh_put(&cstate->current_fh);
     cstate->current_fh.fh_handle.fh_size = putfh->pf_fhlen;
     memcpy(&cstate->current_fh.fh_handle.fh_raw, putfh->pf_fhval,
            putfh->pf_fhlen);
     ret = fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_BYPASS_GSS);
 #ifdef CONFIG_NFSD_V4_2_INTER_SSC
     if (ret == nfserr_stale && putfh->no_verify) {
         SET_FH_FLAG(&cstate->current_fh, NFSD4_FH_FOREIGN);
         ret = 0;
     }
 #endif
     return ret;
 }
 
 static __be32
 nfsd4_putrootfh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         union nfsd4_op_u *u)
 {
     __be32 status;
 
     fh_put(&cstate->current_fh);
     status = exp_pseudoroot(rqstp, &cstate->current_fh);
     return status;
 }
 
 static __be32
 nfsd4_restorefh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         union nfsd4_op_u *u)
 {
     if (!cstate->save_fh.fh_dentry)
         return nfserr_restorefh;
 
     fh_dup2(&cstate->current_fh, &cstate->save_fh);
     if (HAS_CSTATE_FLAG(cstate, SAVED_STATE_ID_FLAG)) {
         memcpy(&cstate->current_stateid, &cstate->save_stateid, sizeof(stateid_t));
         SET_CSTATE_FLAG(cstate, CURRENT_STATE_ID_FLAG);
     }
     return nfs_ok;
 }
 
 static __be32
 nfsd4_savefh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
          union nfsd4_op_u *u)
 {
     fh_dup2(&cstate->save_fh, &cstate->current_fh);
     if (HAS_CSTATE_FLAG(cstate, CURRENT_STATE_ID_FLAG)) {
         memcpy(&cstate->save_stateid, &cstate->current_stateid, sizeof(stateid_t));
         SET_CSTATE_FLAG(cstate, SAVED_STATE_ID_FLAG);
     }
     return nfs_ok;
 }
 
 /*
  * misc nfsv4 ops
  */
 static __be32
 nfsd4_access(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
          union nfsd4_op_u *u)
 {
     struct nfsd4_access *access = &u->access;
     u32 access_full;
 
     access_full = NFS3_ACCESS_FULL;
     if (cstate->minorversion >= 2)
         access_full |= NFS4_ACCESS_XALIST | NFS4_ACCESS_XAREAD |
                    NFS4_ACCESS_XAWRITE;
 
     if (access->ac_req_access & ~access_full)
         return nfserr_inval;
 
     access->ac_resp_access = access->ac_req_access;
     return nfsd_access(rqstp, &cstate->current_fh, &access->ac_resp_access,
                &access->ac_supported);
 }
 
 static void gen_boot_verifier(nfs4_verifier *verifier, struct net *net)
 {
     __be32 *verf = (__be32 *)verifier->data;
 
     BUILD_BUG_ON(2*sizeof(*verf) != sizeof(verifier->data));
 
     nfsd_copy_write_verifier(verf, net_generic(net, nfsd_net_id));
 }
 
 static __be32
 nfsd4_commit(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
          union nfsd4_op_u *u)
 {
     struct nfsd4_commit *commit = &u->commit;
 
     return nfsd_commit(rqstp, &cstate->current_fh, commit->co_offset,
                  commit->co_count,
                  (__be32 *)commit->co_verf.data);
 }
 
 static __be32
 nfsd4_create(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
          union nfsd4_op_u *u)
 {
     struct nfsd4_create *create = &u->create;
     struct nfsd_attrs attrs = {
         .na_iattr   = &create->cr_iattr,
         .na_seclabel    = &create->cr_label,
     };
     struct svc_fh resfh;
     __be32 status;
     dev_t rdev;
 
     fh_init(&resfh, NFS4_FHSIZE);
 
     status = fh_verify(rqstp, &cstate->current_fh, S_IFDIR, NFSD_MAY_NOP);
     if (status)
         return status;
 
     status = check_attr_support(rqstp, cstate, create->cr_bmval,
                     nfsd_attrmask);
     if (status)
         return status;
 
     status = nfsd4_acl_to_attr(create->cr_type, create->cr_acl, &attrs);
     current->fs->umask = create->cr_umask;
     switch (create->cr_type) {
     case NF4LNK:
         status = nfsd_symlink(rqstp, &cstate->current_fh,
                       create->cr_name, create->cr_namelen,
                       create->cr_data, &attrs, &resfh);
         break;
 
     case NF4BLK:
         status = nfserr_inval;
         rdev = MKDEV(create->cr_specdata1, create->cr_specdata2);
         if (MAJOR(rdev) != create->cr_specdata1 ||
             MINOR(rdev) != create->cr_specdata2)
             goto out_umask;
         status = nfsd_create(rqstp, &cstate->current_fh,
                      create->cr_name, create->cr_namelen,
                      &attrs, S_IFBLK, rdev, &resfh);
         break;
 
     case NF4CHR:
         status = nfserr_inval;
         rdev = MKDEV(create->cr_specdata1, create->cr_specdata2);
         if (MAJOR(rdev) != create->cr_specdata1 ||
             MINOR(rdev) != create->cr_specdata2)
             goto out_umask;
         status = nfsd_create(rqstp, &cstate->current_fh,
                      create->cr_name, create->cr_namelen,
                      &attrs, S_IFCHR, rdev, &resfh);
         break;
 
     case NF4SOCK:
         status = nfsd_create(rqstp, &cstate->current_fh,
                      create->cr_name, create->cr_namelen,
                      &attrs, S_IFSOCK, 0, &resfh);
         break;
 
     case NF4FIFO:
         status = nfsd_create(rqstp, &cstate->current_fh,
                      create->cr_name, create->cr_namelen,
                      &attrs, S_IFIFO, 0, &resfh);
         break;
 
     case NF4DIR:
         create->cr_iattr.ia_valid &= ~ATTR_SIZE;
         status = nfsd_create(rqstp, &cstate->current_fh,
                      create->cr_name, create->cr_namelen,
                      &attrs, S_IFDIR, 0, &resfh);
         break;
 
     default:
         status = nfserr_badtype;
     }
 
     if (status)
         goto out;
 
     if (attrs.na_labelerr)
         create->cr_bmval[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
     if (attrs.na_aclerr)
         create->cr_bmval[0] &= ~FATTR4_WORD0_ACL;
     set_change_info(&create->cr_cinfo, &cstate->current_fh);
     fh_dup2(&cstate->current_fh, &resfh);
 out:
     fh_put(&resfh);
 out_umask:
     current->fs->umask = 0;
     nfsd_attrs_free(&attrs);
     return status;
 }
 
 static __be32
 nfsd4_getattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
           union nfsd4_op_u *u)
 {
     struct nfsd4_getattr *getattr = &u->getattr;
     __be32 status;
 
     status = fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_NOP);
     if (status)
         return status;
 
     if (getattr->ga_bmval[1] & NFSD_WRITEONLY_ATTRS_WORD1)
         return nfserr_inval;
 
     getattr->ga_bmval[0] &= nfsd_suppattrs[cstate->minorversion][0];
     getattr->ga_bmval[1] &= nfsd_suppattrs[cstate->minorversion][1];
     getattr->ga_bmval[2] &= nfsd_suppattrs[cstate->minorversion][2];
 
     getattr->ga_fhp = &cstate->current_fh;
     return nfs_ok;
 }
 
 static __be32
 nfsd4_link(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        union nfsd4_op_u *u)
 {
     struct nfsd4_link *link = &u->link;
     __be32 status;
 
     status = nfsd_link(rqstp, &cstate->current_fh,
                link->li_name, link->li_namelen, &cstate->save_fh);
     if (!status)
         set_change_info(&link->li_cinfo, &cstate->current_fh);
     return status;
 }
 
 static __be32 nfsd4_do_lookupp(struct svc_rqst *rqstp, struct svc_fh *fh)
 {
     struct svc_fh tmp_fh;
     __be32 ret;
 
     fh_init(&tmp_fh, NFS4_FHSIZE);
     ret = exp_pseudoroot(rqstp, &tmp_fh);
     if (ret)
         return ret;
     if (tmp_fh.fh_dentry == fh->fh_dentry) {
         fh_put(&tmp_fh);
         return nfserr_noent;
     }
     fh_put(&tmp_fh);
     return nfsd_lookup(rqstp, fh, "..", 2, fh);
 }
 
 static __be32
 nfsd4_lookupp(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
           union nfsd4_op_u *u)
 {
     return nfsd4_do_lookupp(rqstp, &cstate->current_fh);
 }
 
 static __be32
 nfsd4_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
          union nfsd4_op_u *u)
 {
     return nfsd_lookup(rqstp, &cstate->current_fh,
                u->lookup.lo_name, u->lookup.lo_len,
                &cstate->current_fh);
 }
 
 static __be32
 nfsd4_read(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        union nfsd4_op_u *u)
 {
     struct nfsd4_read *read = &u->read;
     __be32 status;
 
     read->rd_nf = NULL;
 
     trace_nfsd_read_start(rqstp, &cstate->current_fh,
                   read->rd_offset, read->rd_length);
 
     read->rd_length = min_t(u32, read->rd_length, svc_max_payload(rqstp));
     if (read->rd_offset > (u64)OFFSET_MAX)
         read->rd_offset = (u64)OFFSET_MAX;
     if (read->rd_offset + read->rd_length > (u64)OFFSET_MAX)
         read->rd_length = (u64)OFFSET_MAX - read->rd_offset;
 
     /*
      * If we do a zero copy read, then a client will see read data
      * that reflects the state of the file *after* performing the
      * following compound.
      *
      * To ensure proper ordering, we therefore turn off zero copy if
      * the client wants us to do more in this compound:
      */
     if (!nfsd4_last_compound_op(rqstp))
         __clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
 
     /* check stateid */
     status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
                     &read->rd_stateid, RD_STATE,
                     &read->rd_nf, NULL);
     if (status) {
         dprintk("NFSD: nfsd4_read: couldn't process stateid!\n");
         goto out;
     }
     status = nfs_ok;
 out:
     read->rd_rqstp = rqstp;
     read->rd_fhp = &cstate->current_fh;
     return status;
 }
 
 
 static void
 nfsd4_read_release(union nfsd4_op_u *u)
 {
     if (u->read.rd_nf)
         nfsd_file_put(u->read.rd_nf);
     trace_nfsd_read_done(u->read.rd_rqstp, u->read.rd_fhp,
                  u->read.rd_offset, u->read.rd_length);
 }
 
 static __be32
 nfsd4_readdir(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
           union nfsd4_op_u *u)
 {
     struct nfsd4_readdir *readdir = &u->readdir;
     u64 cookie = readdir->rd_cookie;
     static const nfs4_verifier zeroverf;
 
     /* no need to check permission - this will be done in nfsd_readdir() */
 
     if (readdir->rd_bmval[1] & NFSD_WRITEONLY_ATTRS_WORD1)
         return nfserr_inval;
 
     readdir->rd_bmval[0] &= nfsd_suppattrs[cstate->minorversion][0];
     readdir->rd_bmval[1] &= nfsd_suppattrs[cstate->minorversion][1];
     readdir->rd_bmval[2] &= nfsd_suppattrs[cstate->minorversion][2];
 
     if ((cookie == 1) || (cookie == 2) ||
         (cookie == 0 && memcmp(readdir->rd_verf.data, zeroverf.data, NFS4_VERIFIER_SIZE)))
         return nfserr_bad_cookie;
 
     readdir->rd_rqstp = rqstp;
     readdir->rd_fhp = &cstate->current_fh;
     return nfs_ok;
 }
 
 static __be32
 nfsd4_readlink(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
            union nfsd4_op_u *u)
 {
     u->readlink.rl_rqstp = rqstp;
     u->readlink.rl_fhp = &cstate->current_fh;
     return nfs_ok;
 }
 
 static __be32
 nfsd4_remove(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
          union nfsd4_op_u *u)
 {
     struct nfsd4_remove *remove = &u->remove;
     __be32 status;
 
     if (opens_in_grace(SVC_NET(rqstp)))
         return nfserr_grace;
     status = nfsd_unlink(rqstp, &cstate->current_fh, 0,
                  remove->rm_name, remove->rm_namelen);
     if (!status)
         set_change_info(&remove->rm_cinfo, &cstate->current_fh);
     return status;
 }
 
 static __be32
 nfsd4_rename(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
          union nfsd4_op_u *u)
 {
     struct nfsd4_rename *rename = &u->rename;
     __be32 status;
 
     if (opens_in_grace(SVC_NET(rqstp)))
         return nfserr_grace;
     status = nfsd_rename(rqstp, &cstate->save_fh, rename->rn_sname,
                  rename->rn_snamelen, &cstate->current_fh,
                  rename->rn_tname, rename->rn_tnamelen);
     if (status)
         return status;
     set_change_info(&rename->rn_sinfo, &cstate->current_fh);
     set_change_info(&rename->rn_tinfo, &cstate->save_fh);
     return nfs_ok;
 }
 
 static __be32
 nfsd4_secinfo(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
           union nfsd4_op_u *u)
 {
     struct nfsd4_secinfo *secinfo = &u->secinfo;
     struct svc_export *exp;
     struct dentry *dentry;
     __be32 err;
 
     err = fh_verify(rqstp, &cstate->current_fh, S_IFDIR, NFSD_MAY_EXEC);
     if (err)
         return err;
     err = nfsd_lookup_dentry(rqstp, &cstate->current_fh,
                     secinfo->si_name, secinfo->si_namelen,
                     &exp, &dentry);
     if (err)
         return err;
     if (d_really_is_negative(dentry)) {
         exp_put(exp);
         err = nfserr_noent;
     } else
         secinfo->si_exp = exp;
     dput(dentry);
     if (cstate->minorversion)
         /* See rfc 5661 section 2.6.3.1.1.8 */
         fh_put(&cstate->current_fh);
     return err;
 }
 
 static __be32
 nfsd4_secinfo_no_name(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         union nfsd4_op_u *u)
 {
     __be32 err;
 
     switch (u->secinfo_no_name.sin_style) {
     case NFS4_SECINFO_STYLE4_CURRENT_FH:
         break;
     case NFS4_SECINFO_STYLE4_PARENT:
         err = nfsd4_do_lookupp(rqstp, &cstate->current_fh);
         if (err)
             return err;
         break;
     default:
         return nfserr_inval;
     }
 
     u->secinfo_no_name.sin_exp = exp_get(cstate->current_fh.fh_export);
     fh_put(&cstate->current_fh);
     return nfs_ok;
 }
 
 static void
 nfsd4_secinfo_release(union nfsd4_op_u *u)
 {
     if (u->secinfo.si_exp)
         exp_put(u->secinfo.si_exp);
 }
 
 static void
 nfsd4_secinfo_no_name_release(union nfsd4_op_u *u)
 {
     if (u->secinfo_no_name.sin_exp)
         exp_put(u->secinfo_no_name.sin_exp);
 }
 
 static __be32
 nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
           union nfsd4_op_u *u)
 {
     struct nfsd4_setattr *setattr = &u->setattr;
     struct nfsd_attrs attrs = {
         .na_iattr   = &setattr->sa_iattr,
         .na_seclabel    = &setattr->sa_label,
     };
     struct inode *inode;
     __be32 status = nfs_ok;
     int err;
 
     if (setattr->sa_iattr.ia_valid & ATTR_SIZE) {
         status = nfs4_preprocess_stateid_op(rqstp, cstate,
                 &cstate->current_fh, &setattr->sa_stateid,
                 WR_STATE, NULL, NULL);
         if (status) {
             dprintk("NFSD: nfsd4_setattr: couldn't process stateid!\n");
             return status;
         }
     }
     err = fh_want_write(&cstate->current_fh);
     if (err)
         return nfserrno(err);
     status = nfs_ok;
 
     status = check_attr_support(rqstp, cstate, setattr->sa_bmval,
                     nfsd_attrmask);
     if (status)
         goto out;
 
     inode = cstate->current_fh.fh_dentry->d_inode;
     status = nfsd4_acl_to_attr(S_ISDIR(inode->i_mode) ? NF4DIR : NF4REG,
                    setattr->sa_acl, &attrs);
 
     if (status)
         goto out;
     status = nfsd_setattr(rqstp, &cstate->current_fh, &attrs,
                 0, (time64_t)0);
     if (!status)
         status = nfserrno(attrs.na_labelerr);
 out:
     nfsd_attrs_free(&attrs);
     fh_drop_write(&cstate->current_fh);
     return status;
 }
 
 static __be32
 nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         union nfsd4_op_u *u)
 {
     struct nfsd4_write *write = &u->write;
     stateid_t *stateid = &write->wr_stateid;
     struct nfsd_file *nf = NULL;
     __be32 status = nfs_ok;
     unsigned long cnt;
     int nvecs;
 
     if (write->wr_offset > (u64)OFFSET_MAX ||
         write->wr_offset + write->wr_buflen > (u64)OFFSET_MAX)
         return nfserr_fbig;
 
     cnt = write->wr_buflen;
     trace_nfsd_write_start(rqstp, &cstate->current_fh,
                    write->wr_offset, cnt);
     status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
                         stateid, WR_STATE, &nf, NULL);
     if (status) {
         dprintk("NFSD: nfsd4_write: couldn't process stateid!\n");
         return status;
     }
 
     write->wr_how_written = write->wr_stable_how;
 
     nvecs = svc_fill_write_vector(rqstp, &write->wr_payload);
     WARN_ON_ONCE(nvecs > ARRAY_SIZE(rqstp->rq_vec));
 
     status = nfsd_vfs_write(rqstp, &cstate->current_fh, nf,
                 write->wr_offset, rqstp->rq_vec, nvecs, &cnt,
                 write->wr_how_written,
                 (__be32 *)write->wr_verifier.data);
     nfsd_file_put(nf);
 
     write->wr_bytes_written = cnt;
     trace_nfsd_write_done(rqstp, &cstate->current_fh,
                   write->wr_offset, cnt);
     return status;
 }
 
 static __be32
 nfsd4_verify_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
           stateid_t *src_stateid, struct nfsd_file **src,
           stateid_t *dst_stateid, struct nfsd_file **dst)
 {
     __be32 status;
 
     if (!cstate->save_fh.fh_dentry)
         return nfserr_nofilehandle;
 
     status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->save_fh,
                         src_stateid, RD_STATE, src, NULL);
     if (status) {
         dprintk("NFSD: %s: couldn't process src stateid!\n", __func__);
         goto out;
     }
 
     status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
                         dst_stateid, WR_STATE, dst, NULL);
     if (status) {
         dprintk("NFSD: %s: couldn't process dst stateid!\n", __func__);
         goto out_put_src;
     }
 
     /* fix up for NFS-specific error code */
     if (!S_ISREG(file_inode((*src)->nf_file)->i_mode) ||
         !S_ISREG(file_inode((*dst)->nf_file)->i_mode)) {
         status = nfserr_wrong_type;
         goto out_put_dst;
     }
 
 out:
     return status;
 out_put_dst:
     nfsd_file_put(*dst);
 out_put_src:
     nfsd_file_put(*src);
     goto out;
 }
 
 static __be32
 nfsd4_clone(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         union nfsd4_op_u *u)
 {
     struct nfsd4_clone *clone = &u->clone;
     struct nfsd_file *src, *dst;
     __be32 status;
 
     status = nfsd4_verify_copy(rqstp, cstate, &clone->cl_src_stateid, &src,
                    &clone->cl_dst_stateid, &dst);
     if (status)
         goto out;
 
     status = nfsd4_clone_file_range(rqstp, src, clone->cl_src_pos,
             dst, clone->cl_dst_pos, clone->cl_count,
             EX_ISSYNC(cstate->current_fh.fh_export));
 
     nfsd_file_put(dst);
     nfsd_file_put(src);
 out:
     return status;
 }
 
 static void nfs4_put_copy(struct nfsd4_copy *copy)
 {
     if (!refcount_dec_and_test(&copy->refcount))
         return;
     kfree(copy->cp_src);
     kfree(copy);
 }
 
 static void nfsd4_stop_copy(struct nfsd4_copy *copy)
 {
     if (!test_and_set_bit(NFSD4_COPY_F_STOPPED, &copy->cp_flags))
         kthread_stop(copy->copy_task);
     nfs4_put_copy(copy);
 }
 
 static struct nfsd4_copy *nfsd4_get_copy(struct nfs4_client *clp)
 {
     struct nfsd4_copy *copy = NULL;
 
     spin_lock(&clp->async_lock);
     if (!list_empty(&clp->async_copies)) {
         copy = list_first_entry(&clp->async_copies, struct nfsd4_copy,
                     copies);
         refcount_inc(&copy->refcount);
     }
     spin_unlock(&clp->async_lock);
     return copy;
 }
 
 void nfsd4_shutdown_copy(struct nfs4_client *clp)
 {
     struct nfsd4_copy *copy;
 
     while ((copy = nfsd4_get_copy(clp)) != NULL)
         nfsd4_stop_copy(copy);
 }
 #ifdef CONFIG_NFSD_V4_2_INTER_SSC
 
 extern struct file *nfs42_ssc_open(struct vfsmount *ss_mnt,
                    struct nfs_fh *src_fh,
                    nfs4_stateid *stateid);
 extern void nfs42_ssc_close(struct file *filep);
 
 extern void nfs_sb_deactive(struct super_block *sb);
 
 #define NFSD42_INTERSSC_MOUNTOPS "vers=4.2,addr=%s,sec=sys"
 
 /*
  * setup a work entry in the ssc delayed unmount list.
  */
 static __be32 nfsd4_ssc_setup_dul(struct nfsd_net *nn, char *ipaddr,
         struct nfsd4_ssc_umount_item **retwork, struct vfsmount **ss_mnt)
 {
     struct nfsd4_ssc_umount_item *ni = NULL;
     struct nfsd4_ssc_umount_item *work = NULL;
     struct nfsd4_ssc_umount_item *tmp;
     DEFINE_WAIT(wait);
 
     *ss_mnt = NULL;
     *retwork = NULL;
     work = kzalloc(sizeof(*work), GFP_KERNEL);
 try_again:
     spin_lock(&nn->nfsd_ssc_lock);
     list_for_each_entry_safe(ni, tmp, &nn->nfsd_ssc_mount_list, nsui_list) {
         if (strncmp(ni->nsui_ipaddr, ipaddr, sizeof(ni->nsui_ipaddr)))
             continue;
         /* found a match */
         if (ni->nsui_busy) {
             /*  wait - and try again */
             prepare_to_wait(&nn->nfsd_ssc_waitq, &wait,
                 TASK_INTERRUPTIBLE);
             spin_unlock(&nn->nfsd_ssc_lock);
 
             /* allow 20secs for mount/unmount for now - revisit */
             if (signal_pending(current) ||
                     (schedule_timeout(20*HZ) == 0)) {
                 kfree(work);
                 return nfserr_eagain;
             }
             finish_wait(&nn->nfsd_ssc_waitq, &wait);
             goto try_again;
         }
         *ss_mnt = ni->nsui_vfsmount;
         refcount_inc(&ni->nsui_refcnt);
         spin_unlock(&nn->nfsd_ssc_lock);
         kfree(work);
 
         /* return vfsmount in ss_mnt */
         return 0;
     }
     if (work) {
         strlcpy(work->nsui_ipaddr, ipaddr, sizeof(work->nsui_ipaddr) - 1);
         refcount_set(&work->nsui_refcnt, 2);
         work->nsui_busy = true;
         list_add_tail(&work->nsui_list, &nn->nfsd_ssc_mount_list);
         *retwork = work;
     }
     spin_unlock(&nn->nfsd_ssc_lock);
     return 0;
 }
 
 static void nfsd4_ssc_update_dul_work(struct nfsd_net *nn,
         struct nfsd4_ssc_umount_item *work, struct vfsmount *ss_mnt)
 {
     /* set nsui_vfsmount, clear busy flag and wakeup waiters */
     spin_lock(&nn->nfsd_ssc_lock);
     work->nsui_vfsmount = ss_mnt;
     work->nsui_busy = false;
     wake_up_all(&nn->nfsd_ssc_waitq);
     spin_unlock(&nn->nfsd_ssc_lock);
 }
 
 static void nfsd4_ssc_cancel_dul_work(struct nfsd_net *nn,
         struct nfsd4_ssc_umount_item *work)
 {
     spin_lock(&nn->nfsd_ssc_lock);
     list_del(&work->nsui_list);
     wake_up_all(&nn->nfsd_ssc_waitq);
     spin_unlock(&nn->nfsd_ssc_lock);
     kfree(work);
 }
 
 /*
  * Support one copy source server for now.
  */
 static __be32
 nfsd4_interssc_connect(struct nl4_server *nss, struct svc_rqst *rqstp,
                struct vfsmount **mount)
 {
     struct file_system_type *type;
     struct vfsmount *ss_mnt;
     struct nfs42_netaddr *naddr;
     struct sockaddr_storage tmp_addr;
     size_t tmp_addrlen, match_netid_len = 3;
     char *startsep = "", *endsep = "", *match_netid = "tcp";
     char *ipaddr, *dev_name, *raw_data;
     int len, raw_len;
     __be32 status = nfserr_inval;
     struct nfsd4_ssc_umount_item *work = NULL;
     struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 
     naddr = &nss->u.nl4_addr;
     tmp_addrlen = rpc_uaddr2sockaddr(SVC_NET(rqstp), naddr->addr,
                      naddr->addr_len,
                      (struct sockaddr *)&tmp_addr,
                      sizeof(tmp_addr));
     if (tmp_addrlen == 0)
         goto out_err;
 
     if (tmp_addr.ss_family == AF_INET6) {
         startsep = "[";
         endsep = "]";
         match_netid = "tcp6";
         match_netid_len = 4;
     }
 
     if (naddr->netid_len != match_netid_len ||
         strncmp(naddr->netid, match_netid, naddr->netid_len))
         goto out_err;
 
     /* Construct the raw data for the vfs_kern_mount call */
     len = RPC_MAX_ADDRBUFLEN + 1;
     ipaddr = kzalloc(len, GFP_KERNEL);
     if (!ipaddr)
         goto out_err;
 
     rpc_ntop((struct sockaddr *)&tmp_addr, ipaddr, len);
 
     /* 2 for ipv6 endsep and startsep. 3 for ":/" and trailing '/0'*/
 
     raw_len = strlen(NFSD42_INTERSSC_MOUNTOPS) + strlen(ipaddr);
     raw_data = kzalloc(raw_len, GFP_KERNEL);
     if (!raw_data)
         goto out_free_ipaddr;
 
     snprintf(raw_data, raw_len, NFSD42_INTERSSC_MOUNTOPS, ipaddr);
 
     status = nfserr_nodev;
     type = get_fs_type("nfs");
     if (!type)
         goto out_free_rawdata;
 
     /* Set the server:<export> for the vfs_kern_mount call */
     dev_name = kzalloc(len + 5, GFP_KERNEL);
     if (!dev_name)
         goto out_free_rawdata;
     snprintf(dev_name, len + 5, "%s%s%s:/", startsep, ipaddr, endsep);
 
     status = nfsd4_ssc_setup_dul(nn, ipaddr, &work, &ss_mnt);
     if (status)
         goto out_free_devname;
     if (ss_mnt)
         goto out_done;
 
     /* Use an 'internal' mount: SB_KERNMOUNT -> MNT_INTERNAL */
     ss_mnt = vfs_kern_mount(type, SB_KERNMOUNT, dev_name, raw_data);
     module_put(type->owner);
     if (IS_ERR(ss_mnt)) {
         status = nfserr_nodev;
         if (work)
             nfsd4_ssc_cancel_dul_work(nn, work);
         goto out_free_devname;
     }
     if (work)
         nfsd4_ssc_update_dul_work(nn, work, ss_mnt);
 out_done:
     status = 0;
     *mount = ss_mnt;
 
 out_free_devname:
     kfree(dev_name);
 out_free_rawdata:
     kfree(raw_data);
 out_free_ipaddr:
     kfree(ipaddr);
 out_err:
     return status;
 }
 
 static void
 nfsd4_interssc_disconnect(struct vfsmount *ss_mnt)
 {
     nfs_do_sb_deactive(ss_mnt->mnt_sb);
     mntput(ss_mnt);
 }
 
 /*
  * Verify COPY destination stateid.
  *
  * Connect to the source server with NFSv4.1.
  * Create the source struct file for nfsd_copy_range.
  * Called with COPY cstate:
  *    SAVED_FH: source filehandle
  *    CURRENT_FH: destination filehandle
  */
 static __be32
 nfsd4_setup_inter_ssc(struct svc_rqst *rqstp,
               struct nfsd4_compound_state *cstate,
               struct nfsd4_copy *copy, struct vfsmount **mount)
 {
     struct svc_fh *s_fh = NULL;
     stateid_t *s_stid = &copy->cp_src_stateid;
     __be32 status = nfserr_inval;
 
     /* Verify the destination stateid and set dst struct file*/
     status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
                         &copy->cp_dst_stateid,
                         WR_STATE, &copy->nf_dst, NULL);
     if (status)
         goto out;
 
     status = nfsd4_interssc_connect(copy->cp_src, rqstp, mount);
     if (status)
         goto out;
 
     s_fh = &cstate->save_fh;
 
     copy->c_fh.size = s_fh->fh_handle.fh_size;
     memcpy(copy->c_fh.data, &s_fh->fh_handle.fh_raw, copy->c_fh.size);
     copy->stateid.seqid = cpu_to_be32(s_stid->si_generation);
     memcpy(copy->stateid.other, (void *)&s_stid->si_opaque,
            sizeof(stateid_opaque_t));
 
     status = 0;
 out:
     return status;
 }
 
 static void
 nfsd4_cleanup_inter_ssc(struct vfsmount *ss_mnt, struct file *filp,
             struct nfsd_file *dst)
 {
     bool found = false;
     long timeout;
     struct nfsd4_ssc_umount_item *tmp;
     struct nfsd4_ssc_umount_item *ni = NULL;
     struct nfsd_net *nn = net_generic(dst->nf_net, nfsd_net_id);
 
     nfs42_ssc_close(filp);
     nfsd_file_put(dst);
     fput(filp);
 
     if (!nn) {
         mntput(ss_mnt);
         return;
     }
     spin_lock(&nn->nfsd_ssc_lock);
     timeout = msecs_to_jiffies(nfsd4_ssc_umount_timeout);
     list_for_each_entry_safe(ni, tmp, &nn->nfsd_ssc_mount_list, nsui_list) {
         if (ni->nsui_vfsmount->mnt_sb == ss_mnt->mnt_sb) {
             list_del(&ni->nsui_list);
             /*
              * vfsmount can be shared by multiple exports,
              * decrement refcnt. If the count drops to 1 it
              * will be unmounted when nsui_expire expires.
              */
             refcount_dec(&ni->nsui_refcnt);
             ni->nsui_expire = jiffies + timeout;
             list_add_tail(&ni->nsui_list, &nn->nfsd_ssc_mount_list);
             found = true;
             break;
         }
     }
     spin_unlock(&nn->nfsd_ssc_lock);
     if (!found) {
         mntput(ss_mnt);
         return;
     }
 }
 
 #else /* CONFIG_NFSD_V4_2_INTER_SSC */
 
 static __be32
 nfsd4_setup_inter_ssc(struct svc_rqst *rqstp,
               struct nfsd4_compound_state *cstate,
               struct nfsd4_copy *copy,
               struct vfsmount **mount)
 {
     *mount = NULL;
     return nfserr_inval;
 }
 
 static void
 nfsd4_cleanup_inter_ssc(struct vfsmount *ss_mnt, struct file *filp,
             struct nfsd_file *dst)
 {
 }
 
 static void
 nfsd4_interssc_disconnect(struct vfsmount *ss_mnt)
 {
 }
 
 static struct file *nfs42_ssc_open(struct vfsmount *ss_mnt,
                    struct nfs_fh *src_fh,
                    nfs4_stateid *stateid)
 {
     return NULL;
 }
 #endif /* CONFIG_NFSD_V4_2_INTER_SSC */
 
 static __be32
 nfsd4_setup_intra_ssc(struct svc_rqst *rqstp,
               struct nfsd4_compound_state *cstate,
               struct nfsd4_copy *copy)
 {
     return nfsd4_verify_copy(rqstp, cstate, &copy->cp_src_stateid,
                  &copy->nf_src, &copy->cp_dst_stateid,
                  &copy->nf_dst);
 }
 
 static void
 nfsd4_cleanup_intra_ssc(struct nfsd_file *src, struct nfsd_file *dst)
 {
     nfsd_file_put(src);
     nfsd_file_put(dst);
 }
 
 static void nfsd4_cb_offload_release(struct nfsd4_callback *cb)
 {
     struct nfsd4_cb_offload *cbo =
         container_of(cb, struct nfsd4_cb_offload, co_cb);
 
     kfree(cbo);
 }
 
 static int nfsd4_cb_offload_done(struct nfsd4_callback *cb,
                  struct rpc_task *task)
 {
     return 1;
 }
 
 static const struct nfsd4_callback_ops nfsd4_cb_offload_ops = {
     .release = nfsd4_cb_offload_release,
     .done = nfsd4_cb_offload_done
 };
 
 static void nfsd4_init_copy_res(struct nfsd4_copy *copy, bool sync)
 {
     copy->cp_res.wr_stable_how =
         test_bit(NFSD4_COPY_F_COMMITTED, &copy->cp_flags) ?
             NFS_FILE_SYNC : NFS_UNSTABLE;
     nfsd4_copy_set_sync(copy, sync);
     gen_boot_verifier(&copy->cp_res.wr_verifier, copy->cp_clp->net);
 }
 
 static ssize_t _nfsd_copy_file_range(struct nfsd4_copy *copy,
                      struct file *dst,
                      struct file *src)
 {
     errseq_t since;
     ssize_t bytes_copied = 0;
     u64 bytes_total = copy->cp_count;
     u64 src_pos = copy->cp_src_pos;
     u64 dst_pos = copy->cp_dst_pos;
     int status;
 
     /* See RFC 7862 p.67: */
     if (bytes_total == 0)
         bytes_total = ULLONG_MAX;
     do {
         if (kthread_should_stop())
             break;
         bytes_copied = nfsd_copy_file_range(src, src_pos, dst, dst_pos,
                             bytes_total);
         if (bytes_copied <= 0)
             break;
         bytes_total -= bytes_copied;
         copy->cp_res.wr_bytes_written += bytes_copied;
         src_pos += bytes_copied;
         dst_pos += bytes_copied;
     } while (bytes_total > 0 && nfsd4_copy_is_async(copy));
     /* for a non-zero asynchronous copy do a commit of data */
     if (nfsd4_copy_is_async(copy) && copy->cp_res.wr_bytes_written > 0) {
         since = READ_ONCE(dst->f_wb_err);
         status = vfs_fsync_range(dst, copy->cp_dst_pos,
                      copy->cp_res.wr_bytes_written, 0);
         if (!status)
             status = filemap_check_wb_err(dst->f_mapping, since);
         if (!status)
             set_bit(NFSD4_COPY_F_COMMITTED, &copy->cp_flags);
     }
     return bytes_copied;
 }
 
 static __be32 nfsd4_do_copy(struct nfsd4_copy *copy,
                 struct file *src, struct file *dst,
                 bool sync)
 {
     __be32 status;
     ssize_t bytes;
 
     bytes = _nfsd_copy_file_range(copy, dst, src);
 
     /* for async copy, we ignore the error, client can always retry
      * to get the error
      */
     if (bytes < 0 && !copy->cp_res.wr_bytes_written)
         status = nfserrno(bytes);
     else {
         nfsd4_init_copy_res(copy, sync);
         status = nfs_ok;
     }
     return status;
 }
 
 static void dup_copy_fields(struct nfsd4_copy *src, struct nfsd4_copy *dst)
 {
     dst->cp_src_pos = src->cp_src_pos;
     dst->cp_dst_pos = src->cp_dst_pos;
     dst->cp_count = src->cp_count;
     dst->cp_flags = src->cp_flags;
     memcpy(&dst->cp_res, &src->cp_res, sizeof(src->cp_res));
     memcpy(&dst->fh, &src->fh, sizeof(src->fh));
     dst->cp_clp = src->cp_clp;
     dst->nf_dst = nfsd_file_get(src->nf_dst);
     /* for inter, nf_src doesn't exist yet */
     if (!nfsd4_ssc_is_inter(src))
         dst->nf_src = nfsd_file_get(src->nf_src);
 
     memcpy(&dst->cp_stateid, &src->cp_stateid, sizeof(src->cp_stateid));
     memcpy(dst->cp_src, src->cp_src, sizeof(struct nl4_server));
     memcpy(&dst->stateid, &src->stateid, sizeof(src->stateid));
     memcpy(&dst->c_fh, &src->c_fh, sizeof(src->c_fh));
     dst->ss_mnt = src->ss_mnt;
 }
 
 static void cleanup_async_copy(struct nfsd4_copy *copy)
 {
     nfs4_free_copy_state(copy);
     nfsd_file_put(copy->nf_dst);
     if (!nfsd4_ssc_is_inter(copy))
         nfsd_file_put(copy->nf_src);
     spin_lock(&copy->cp_clp->async_lock);
     list_del(&copy->copies);
     spin_unlock(&copy->cp_clp->async_lock);
     nfs4_put_copy(copy);
 }
 
 static void nfsd4_send_cb_offload(struct nfsd4_copy *copy, __be32 nfserr)
 {
     struct nfsd4_cb_offload *cbo;
 
     cbo = kzalloc(sizeof(*cbo), GFP_KERNEL);
     if (!cbo)
         return;
 
     memcpy(&cbo->co_res, &copy->cp_res, sizeof(copy->cp_res));
     memcpy(&cbo->co_fh, &copy->fh, sizeof(copy->fh));
     cbo->co_nfserr = nfserr;
 
     nfsd4_init_cb(&cbo->co_cb, copy->cp_clp, &nfsd4_cb_offload_ops,
               NFSPROC4_CLNT_CB_OFFLOAD);
     trace_nfsd_cb_offload(copy->cp_clp, &cbo->co_res.cb_stateid,
                   &cbo->co_fh, copy->cp_count, nfserr);
     nfsd4_run_cb(&cbo->co_cb);
 }
 
 /**
  * nfsd4_do_async_copy - kthread function for background server-side COPY
  * @data: arguments for COPY operation
  *
  * Return values:
  *   %0: Copy operation is done.
  */
 static int nfsd4_do_async_copy(void *data)
 {
     struct nfsd4_copy *copy = (struct nfsd4_copy *)data;
     __be32 nfserr;
 
     if (nfsd4_ssc_is_inter(copy)) {
         struct file *filp;
 
         filp = nfs42_ssc_open(copy->ss_mnt, &copy->c_fh,
                       &copy->stateid);
         if (IS_ERR(filp)) {
             nfserr = nfserr_offload_denied;
             nfsd4_interssc_disconnect(copy->ss_mnt);
             goto do_callback;
         }
         nfserr = nfsd4_do_copy(copy, filp, copy->nf_dst->nf_file,
                        false);
         nfsd4_cleanup_inter_ssc(copy->ss_mnt, filp, copy->nf_dst);
     } else {
         nfserr = nfsd4_do_copy(copy, copy->nf_src->nf_file,
                        copy->nf_dst->nf_file, false);
         nfsd4_cleanup_intra_ssc(copy->nf_src, copy->nf_dst);
     }
 
 do_callback:
     nfsd4_send_cb_offload(copy, nfserr);
     cleanup_async_copy(copy);
     return 0;
 }
 
 static __be32
 nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         union nfsd4_op_u *u)
 {
     struct nfsd4_copy *copy = &u->copy;
     __be32 status;
     struct nfsd4_copy *async_copy = NULL;
 
     if (nfsd4_ssc_is_inter(copy)) {
         if (!inter_copy_offload_enable || nfsd4_copy_is_sync(copy)) {
             status = nfserr_notsupp;
             goto out;
         }
         status = nfsd4_setup_inter_ssc(rqstp, cstate, copy,
                 &copy->ss_mnt);
         if (status)
             return nfserr_offload_denied;
     } else {
         status = nfsd4_setup_intra_ssc(rqstp, cstate, copy);
         if (status)
             return status;
     }
 
     copy->cp_clp = cstate->clp;
     memcpy(&copy->fh, &cstate->current_fh.fh_handle,
         sizeof(struct knfsd_fh));
     if (nfsd4_copy_is_async(copy)) {
         struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 
         status = nfserrno(-ENOMEM);
         async_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL);
         if (!async_copy)
             goto out_err;
         async_copy->cp_src = kmalloc(sizeof(*async_copy->cp_src), GFP_KERNEL);
         if (!async_copy->cp_src)
             goto out_err;
         if (!nfs4_init_copy_state(nn, copy))
             goto out_err;
         refcount_set(&async_copy->refcount, 1);
         memcpy(&copy->cp_res.cb_stateid, &copy->cp_stateid.stid,
             sizeof(copy->cp_res.cb_stateid));
         dup_copy_fields(copy, async_copy);
         async_copy->copy_task = kthread_create(nfsd4_do_async_copy,
                 async_copy, "%s", "copy thread");
         if (IS_ERR(async_copy->copy_task))
             goto out_err;
         spin_lock(&async_copy->cp_clp->async_lock);
         list_add(&async_copy->copies,
                 &async_copy->cp_clp->async_copies);
         spin_unlock(&async_copy->cp_clp->async_lock);
         wake_up_process(async_copy->copy_task);
         status = nfs_ok;
     } else {
         status = nfsd4_do_copy(copy, copy->nf_src->nf_file,
                        copy->nf_dst->nf_file, true);
         nfsd4_cleanup_intra_ssc(copy->nf_src, copy->nf_dst);
     }
 out:
     return status;
 out_err:
     if (async_copy)
         cleanup_async_copy(async_copy);
     status = nfserrno(-ENOMEM);
     if (nfsd4_ssc_is_inter(copy))
         nfsd4_interssc_disconnect(copy->ss_mnt);
     goto out;
 }
 
 struct nfsd4_copy *
 find_async_copy(struct nfs4_client *clp, stateid_t *stateid)
 {
     struct nfsd4_copy *copy;
 
     spin_lock(&clp->async_lock);
     list_for_each_entry(copy, &clp->async_copies, copies) {
         if (memcmp(&copy->cp_stateid.stid, stateid, NFS4_STATEID_SIZE))
             continue;
         refcount_inc(&copy->refcount);
         spin_unlock(&clp->async_lock);
         return copy;
     }
     spin_unlock(&clp->async_lock);
     return NULL;
 }
 
 static __be32
 nfsd4_offload_cancel(struct svc_rqst *rqstp,
              struct nfsd4_compound_state *cstate,
              union nfsd4_op_u *u)
 {
     struct nfsd4_offload_status *os = &u->offload_status;
     struct nfsd4_copy *copy;
     struct nfs4_client *clp = cstate->clp;
 
     copy = find_async_copy(clp, &os->stateid);
     if (!copy) {
         struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 
         return manage_cpntf_state(nn, &os->stateid, clp, NULL);
     } else
         nfsd4_stop_copy(copy);
 
     return nfs_ok;
 }
 
 static __be32
 nfsd4_copy_notify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
           union nfsd4_op_u *u)
 {
     struct nfsd4_copy_notify *cn = &u->copy_notify;
     __be32 status;
     struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
     struct nfs4_stid *stid;
     struct nfs4_cpntf_state *cps;
     struct nfs4_client *clp = cstate->clp;
 
     status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
                     &cn->cpn_src_stateid, RD_STATE, NULL,
                     &stid);
     if (status)
         return status;
 
     cn->cpn_sec = nn->nfsd4_lease;
     cn->cpn_nsec = 0;
 
     status = nfserrno(-ENOMEM);
     cps = nfs4_alloc_init_cpntf_state(nn, stid);
     if (!cps)
         goto out;
     memcpy(&cn->cpn_cnr_stateid, &cps->cp_stateid.stid, sizeof(stateid_t));
     memcpy(&cps->cp_p_stateid, &stid->sc_stateid, sizeof(stateid_t));
     memcpy(&cps->cp_p_clid, &clp->cl_clientid, sizeof(clientid_t));
 
     /* For now, only return one server address in cpn_src, the
      * address used by the client to connect to this server.
      */
     cn->cpn_src->nl4_type = NL4_NETADDR;
     status = nfsd4_set_netaddr((struct sockaddr *)&rqstp->rq_daddr,
                  &cn->cpn_src->u.nl4_addr);
     WARN_ON_ONCE(status);
     if (status) {
         nfs4_put_cpntf_state(nn, cps);
         goto out;
     }
 out:
     nfs4_put_stid(stid);
     return status;
 }
 
 static __be32
 nfsd4_fallocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         struct nfsd4_fallocate *fallocate, int flags)
 {
     __be32 status;
     struct nfsd_file *nf;
 
     status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
                         &fallocate->falloc_stateid,
                         WR_STATE, &nf, NULL);
     if (status != nfs_ok) {
         dprintk("NFSD: nfsd4_fallocate: couldn't process stateid!\n");
         return status;
     }
 
     status = nfsd4_vfs_fallocate(rqstp, &cstate->current_fh, nf->nf_file,
                      fallocate->falloc_offset,
                      fallocate->falloc_length,
                      flags);
     nfsd_file_put(nf);
     return status;
 }
 static __be32
 nfsd4_offload_status(struct svc_rqst *rqstp,
              struct nfsd4_compound_state *cstate,
              union nfsd4_op_u *u)
 {
     struct nfsd4_offload_status *os = &u->offload_status;
     __be32 status = 0;
     struct nfsd4_copy *copy;
     struct nfs4_client *clp = cstate->clp;
 
     copy = find_async_copy(clp, &os->stateid);
     if (copy) {
         os->count = copy->cp_res.wr_bytes_written;
         nfs4_put_copy(copy);
     } else
         status = nfserr_bad_stateid;
 
     return status;
 }
 
 static __be32
 nfsd4_allocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
            union nfsd4_op_u *u)
 {
     return nfsd4_fallocate(rqstp, cstate, &u->allocate, 0);
 }
 
 static __be32
 nfsd4_deallocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
          union nfsd4_op_u *u)
 {
     return nfsd4_fallocate(rqstp, cstate, &u->deallocate,
                    FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE);
 }
 
 static __be32
 nfsd4_seek(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        union nfsd4_op_u *u)
 {
     struct nfsd4_seek *seek = &u->seek;
     int whence;
     __be32 status;
     struct nfsd_file *nf;
 
     status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
                         &seek->seek_stateid,
                         RD_STATE, &nf, NULL);
     if (status) {
         dprintk("NFSD: nfsd4_seek: couldn't process stateid!\n");
         return status;
     }
 
     switch (seek->seek_whence) {
     case NFS4_CONTENT_DATA:
         whence = SEEK_DATA;
         break;
     case NFS4_CONTENT_HOLE:
         whence = SEEK_HOLE;
         break;
     default:
         status = nfserr_union_notsupp;
         goto out;
     }
 
     /*
      * Note:  This call does change file->f_pos, but nothing in NFSD
      *        should ever file->f_pos.
      */
     seek->seek_pos = vfs_llseek(nf->nf_file, seek->seek_offset, whence);
     if (seek->seek_pos < 0)
         status = nfserrno(seek->seek_pos);
     else if (seek->seek_pos >= i_size_read(file_inode(nf->nf_file)))
         seek->seek_eof = true;
 
 out:
     nfsd_file_put(nf);
     return status;
 }
 
 /* This routine never returns NFS_OK!  If there are no other errors, it
  * will return NFSERR_SAME or NFSERR_NOT_SAME depending on whether the
  * attributes matched.  VERIFY is implemented by mapping NFSERR_SAME
  * to NFS_OK after the call; NVERIFY by mapping NFSERR_NOT_SAME to NFS_OK.
  */
 static __be32
 _nfsd4_verify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
          struct nfsd4_verify *verify)
 {
     __be32 *buf, *p;
     int count;
     __be32 status;
 
     status = fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_NOP);
     if (status)
         return status;
 
     status = check_attr_support(rqstp, cstate, verify->ve_bmval, NULL);
     if (status)
         return status;
 
     if ((verify->ve_bmval[0] & FATTR4_WORD0_RDATTR_ERROR)
         || (verify->ve_bmval[1] & NFSD_WRITEONLY_ATTRS_WORD1))
         return nfserr_inval;
     if (verify->ve_attrlen & 3)
         return nfserr_inval;
 
     /* count in words:
      *   bitmap_len(1) + bitmap(2) + attr_len(1) = 4
      */
     count = 4 + (verify->ve_attrlen >> 2);
     buf = kmalloc(count << 2, GFP_KERNEL);
     if (!buf)
         return nfserr_jukebox;
 
     p = buf;
     status = nfsd4_encode_fattr_to_buf(&p, count, &cstate->current_fh,
                     cstate->current_fh.fh_export,
                     cstate->current_fh.fh_dentry,
                     verify->ve_bmval,
                     rqstp, 0);
     /*
      * If nfsd4_encode_fattr() ran out of space, assume that's because
      * the attributes are longer (hence different) than those given:
      */
     if (status == nfserr_resource)
         status = nfserr_not_same;
     if (status)
         goto out_kfree;
 
     /* skip bitmap */
     p = buf + 1 + ntohl(buf[0]);
     status = nfserr_not_same;
     if (ntohl(*p++) != verify->ve_attrlen)
         goto out_kfree;
     if (!memcmp(p, verify->ve_attrval, verify->ve_attrlen))
         status = nfserr_same;
 
 out_kfree:
     kfree(buf);
     return status;
 }
 
 static __be32
 nfsd4_nverify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
           union nfsd4_op_u *u)
 {
     __be32 status;
 
     status = _nfsd4_verify(rqstp, cstate, &u->verify);
     return status == nfserr_not_same ? nfs_ok : status;
 }
 
 static __be32
 nfsd4_verify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
          union nfsd4_op_u *u)
 {
     __be32 status;
 
     status = _nfsd4_verify(rqstp, cstate, &u->nverify);
     return status == nfserr_same ? nfs_ok : status;
 }
 
 #ifdef CONFIG_NFSD_PNFS
 static const struct nfsd4_layout_ops *
 nfsd4_layout_verify(struct svc_export *exp, unsigned int layout_type)
 {
     if (!exp->ex_layout_types) {
         dprintk("%s: export does not support pNFS\n", __func__);
         return NULL;
     }
 
     if (layout_type >= LAYOUT_TYPE_MAX ||
         !(exp->ex_layout_types & (1 << layout_type))) {
         dprintk("%s: layout type %d not supported\n",
             __func__, layout_type);
         return NULL;
     }
 
     return nfsd4_layout_ops[layout_type];
 }
 
 static __be32
 nfsd4_getdeviceinfo(struct svc_rqst *rqstp,
         struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
 {
     struct nfsd4_getdeviceinfo *gdp = &u->getdeviceinfo;
     const struct nfsd4_layout_ops *ops;
     struct nfsd4_deviceid_map *map;
     struct svc_export *exp;
     __be32 nfserr;
 
     dprintk("%s: layout_type %u dev_id [0x%llx:0x%x] maxcnt %u\n",
            __func__,
            gdp->gd_layout_type,
            gdp->gd_devid.fsid_idx, gdp->gd_devid.generation,
            gdp->gd_maxcount);
 
     map = nfsd4_find_devid_map(gdp->gd_devid.fsid_idx);
     if (!map) {
         dprintk("%s: couldn't find device ID to export mapping!\n",
             __func__);
         return nfserr_noent;
     }
 
     exp = rqst_exp_find(rqstp, map->fsid_type, map->fsid);
     if (IS_ERR(exp)) {
         dprintk("%s: could not find device id\n", __func__);
         return nfserr_noent;
     }
 
     nfserr = nfserr_layoutunavailable;
     ops = nfsd4_layout_verify(exp, gdp->gd_layout_type);
     if (!ops)
         goto out;
 
     nfserr = nfs_ok;
     if (gdp->gd_maxcount != 0) {
         nfserr = ops->proc_getdeviceinfo(exp->ex_path.mnt->mnt_sb,
                 rqstp, cstate->clp, gdp);
     }
 
     gdp->gd_notify_types &= ops->notify_types;
 out:
     exp_put(exp);
     return nfserr;
 }
 
 static void
 nfsd4_getdeviceinfo_release(union nfsd4_op_u *u)
 {
     kfree(u->getdeviceinfo.gd_device);
 }
 
 static __be32
 nfsd4_layoutget(struct svc_rqst *rqstp,
         struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
 {
     struct nfsd4_layoutget *lgp = &u->layoutget;
     struct svc_fh *current_fh = &cstate->current_fh;
     const struct nfsd4_layout_ops *ops;
     struct nfs4_layout_stateid *ls;
     __be32 nfserr;
     int accmode = NFSD_MAY_READ_IF_EXEC;
 
     switch (lgp->lg_seg.iomode) {
     case IOMODE_READ:
         accmode |= NFSD_MAY_READ;
         break;
     case IOMODE_RW:
         accmode |= NFSD_MAY_READ | NFSD_MAY_WRITE;
         break;
     default:
         dprintk("%s: invalid iomode %d\n",
             __func__, lgp->lg_seg.iomode);
         nfserr = nfserr_badiomode;
         goto out;
     }
 
     nfserr = fh_verify(rqstp, current_fh, 0, accmode);
     if (nfserr)
         goto out;
 
     nfserr = nfserr_layoutunavailable;
     ops = nfsd4_layout_verify(current_fh->fh_export, lgp->lg_layout_type);
     if (!ops)
         goto out;
 
     /*
      * Verify minlength and range as per RFC5661:
      *  o  If loga_length is less than loga_minlength,
      *     the metadata server MUST return NFS4ERR_INVAL.
      *  o  If the sum of loga_offset and loga_minlength exceeds
      *     NFS4_UINT64_MAX, and loga_minlength is not
      *     NFS4_UINT64_MAX, the error NFS4ERR_INVAL MUST result.
      *  o  If the sum of loga_offset and loga_length exceeds
      *     NFS4_UINT64_MAX, and loga_length is not NFS4_UINT64_MAX,
      *     the error NFS4ERR_INVAL MUST result.
      */
     nfserr = nfserr_inval;
     if (lgp->lg_seg.length < lgp->lg_minlength ||
         (lgp->lg_minlength != NFS4_MAX_UINT64 &&
          lgp->lg_minlength > NFS4_MAX_UINT64 - lgp->lg_seg.offset) ||
         (lgp->lg_seg.length != NFS4_MAX_UINT64 &&
          lgp->lg_seg.length > NFS4_MAX_UINT64 - lgp->lg_seg.offset))
         goto out;
     if (lgp->lg_seg.length == 0)
         goto out;
 
     nfserr = nfsd4_preprocess_layout_stateid(rqstp, cstate, &lgp->lg_sid,
                         true, lgp->lg_layout_type, &ls);
     if (nfserr) {
         trace_nfsd_layout_get_lookup_fail(&lgp->lg_sid);
         goto out;
     }
 
     nfserr = nfserr_recallconflict;
     if (atomic_read(&ls->ls_stid.sc_file->fi_lo_recalls))
         goto out_put_stid;
 
     nfserr = ops->proc_layoutget(d_inode(current_fh->fh_dentry),
                      current_fh, lgp);
     if (nfserr)
         goto out_put_stid;
 
     nfserr = nfsd4_insert_layout(lgp, ls);
 
 out_put_stid:
     mutex_unlock(&ls->ls_mutex);
     nfs4_put_stid(&ls->ls_stid);
 out:
     return nfserr;
 }
 
 static void
 nfsd4_layoutget_release(union nfsd4_op_u *u)
 {
     kfree(u->layoutget.lg_content);
 }
 
 static __be32
 nfsd4_layoutcommit(struct svc_rqst *rqstp,
         struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
 {
     struct nfsd4_layoutcommit *lcp = &u->layoutcommit;
     const struct nfsd4_layout_seg *seg = &lcp->lc_seg;
     struct svc_fh *current_fh = &cstate->current_fh;
     const struct nfsd4_layout_ops *ops;
     loff_t new_size = lcp->lc_last_wr + 1;
     struct inode *inode;
     struct nfs4_layout_stateid *ls;
     __be32 nfserr;
 
     nfserr = fh_verify(rqstp, current_fh, 0, NFSD_MAY_WRITE);
     if (nfserr)
         goto out;
 
     nfserr = nfserr_layoutunavailable;
     ops = nfsd4_layout_verify(current_fh->fh_export, lcp->lc_layout_type);
     if (!ops)
         goto out;
     inode = d_inode(current_fh->fh_dentry);
 
     nfserr = nfserr_inval;
     if (new_size <= seg->offset) {
         dprintk("pnfsd: last write before layout segment\n");
         goto out;
     }
     if (new_size > seg->offset + seg->length) {
         dprintk("pnfsd: last write beyond layout segment\n");
         goto out;
     }
     if (!lcp->lc_newoffset && new_size > i_size_read(inode)) {
         dprintk("pnfsd: layoutcommit beyond EOF\n");
         goto out;
     }
 
     nfserr = nfsd4_preprocess_layout_stateid(rqstp, cstate, &lcp->lc_sid,
                         false, lcp->lc_layout_type,
                         &ls);
     if (nfserr) {
         trace_nfsd_layout_commit_lookup_fail(&lcp->lc_sid);
         /* fixup error code as per RFC5661 */
         if (nfserr == nfserr_bad_stateid)
             nfserr = nfserr_badlayout;
         goto out;
     }
 
     /* LAYOUTCOMMIT does not require any serialization */
     mutex_unlock(&ls->ls_mutex);
 
     if (new_size > i_size_read(inode)) {
         lcp->lc_size_chg = 1;
         lcp->lc_newsize = new_size;
     } else {
         lcp->lc_size_chg = 0;
     }
 
     nfserr = ops->proc_layoutcommit(inode, lcp);
     nfs4_put_stid(&ls->ls_stid);
 out:
     return nfserr;
 }
 
 static __be32
 nfsd4_layoutreturn(struct svc_rqst *rqstp,
         struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
 {
     struct nfsd4_layoutreturn *lrp = &u->layoutreturn;
     struct svc_fh *current_fh = &cstate->current_fh;
     __be32 nfserr;
 
     nfserr = fh_verify(rqstp, current_fh, 0, NFSD_MAY_NOP);
     if (nfserr)
         goto out;
 
     nfserr = nfserr_layoutunavailable;
     if (!nfsd4_layout_verify(current_fh->fh_export, lrp->lr_layout_type))
         goto out;
 
     switch (lrp->lr_seg.iomode) {
     case IOMODE_READ:
     case IOMODE_RW:
     case IOMODE_ANY:
         break;
     default:
         dprintk("%s: invalid iomode %d\n", __func__,
             lrp->lr_seg.iomode);
         nfserr = nfserr_inval;
         goto out;
     }
 
     switch (lrp->lr_return_type) {
     case RETURN_FILE:
         nfserr = nfsd4_return_file_layouts(rqstp, cstate, lrp);
         break;
     case RETURN_FSID:
     case RETURN_ALL:
         nfserr = nfsd4_return_client_layouts(rqstp, cstate, lrp);
         break;
     default:
         dprintk("%s: invalid return_type %d\n", __func__,
             lrp->lr_return_type);
         nfserr = nfserr_inval;
         break;
     }
 out:
     return nfserr;
 }
 #endif /* CONFIG_NFSD_PNFS */
 
 static __be32
 nfsd4_getxattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
            union nfsd4_op_u *u)
 {
     struct nfsd4_getxattr *getxattr = &u->getxattr;
 
     return nfsd_getxattr(rqstp, &cstate->current_fh,
                  getxattr->getxa_name, &getxattr->getxa_buf,
                  &getxattr->getxa_len);
 }
 
 static __be32
 nfsd4_setxattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        union nfsd4_op_u *u)
 {
     struct nfsd4_setxattr *setxattr = &u->setxattr;
     __be32 ret;
 
     if (opens_in_grace(SVC_NET(rqstp)))
         return nfserr_grace;
 
     ret = nfsd_setxattr(rqstp, &cstate->current_fh, setxattr->setxa_name,
                 setxattr->setxa_buf, setxattr->setxa_len,
                 setxattr->setxa_flags);
 
     if (!ret)
         set_change_info(&setxattr->setxa_cinfo, &cstate->current_fh);
 
     return ret;
 }
 
 static __be32
 nfsd4_listxattrs(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        union nfsd4_op_u *u)
 {
     /*
      * Get the entire list, then copy out only the user attributes
      * in the encode function.
      */
     return nfsd_listxattr(rqstp, &cstate->current_fh,
                  &u->listxattrs.lsxa_buf, &u->listxattrs.lsxa_len);
 }
 
 static __be32
 nfsd4_removexattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        union nfsd4_op_u *u)
 {
     struct nfsd4_removexattr *removexattr = &u->removexattr;
     __be32 ret;
 
     if (opens_in_grace(SVC_NET(rqstp)))
         return nfserr_grace;
 
     ret = nfsd_removexattr(rqstp, &cstate->current_fh,
         removexattr->rmxa_name);
 
     if (!ret)
         set_change_info(&removexattr->rmxa_cinfo, &cstate->current_fh);
 
     return ret;
 }
 
 /*
  * NULL call.
  */
 static __be32
 nfsd4_proc_null(struct svc_rqst *rqstp)
 {
     return rpc_success;
 }
 
 static inline void nfsd4_increment_op_stats(u32 opnum)
 {
     if (opnum >= FIRST_NFS4_OP && opnum <= LAST_NFS4_OP)
         percpu_counter_inc(&nfsdstats.counter[NFSD_STATS_NFS4_OP(opnum)]);
 }
 
 static const struct nfsd4_operation nfsd4_ops[];
 
 static const char *nfsd4_op_name(unsigned opnum);
 
 /*
  * Enforce NFSv4.1 COMPOUND ordering rules:
  *
  * Also note, enforced elsewhere:
  *  - SEQUENCE other than as first op results in
  *    NFS4ERR_SEQUENCE_POS. (Enforced in nfsd4_sequence().)
  *  - BIND_CONN_TO_SESSION must be the only op in its compound.
  *    (Enforced in nfsd4_bind_conn_to_session().)
  *  - DESTROY_SESSION must be the final operation in a compound, if
  *    sessionid's in SEQUENCE and DESTROY_SESSION are the same.
  *    (Enforced in nfsd4_destroy_session().)
  */
 static __be32 nfs41_check_op_ordering(struct nfsd4_compoundargs *args)
 {
     struct nfsd4_op *first_op = &args->ops[0];
 
     /* These ordering requirements don't apply to NFSv4.0: */
     if (args->minorversion == 0)
         return nfs_ok;
     /* This is weird, but OK, not our problem: */
     if (args->opcnt == 0)
         return nfs_ok;
     if (first_op->status == nfserr_op_illegal)
         return nfs_ok;
     if (!(nfsd4_ops[first_op->opnum].op_flags & ALLOWED_AS_FIRST_OP))
         return nfserr_op_not_in_session;
     if (first_op->opnum == OP_SEQUENCE)
         return nfs_ok;
     /*
      * So first_op is something allowed outside a session, like
      * EXCHANGE_ID; but then it has to be the only op in the
      * compound:
      */
     if (args->opcnt != 1)
         return nfserr_not_only_op;
     return nfs_ok;
 }
 
 const struct nfsd4_operation *OPDESC(struct nfsd4_op *op)
 {
     return &nfsd4_ops[op->opnum];
 }
 
 bool nfsd4_cache_this_op(struct nfsd4_op *op)
 {
     if (op->opnum == OP_ILLEGAL)
         return false;
     return OPDESC(op)->op_flags & OP_CACHEME;
 }
 
 static bool need_wrongsec_check(struct svc_rqst *rqstp)
 {
     struct nfsd4_compoundres *resp = rqstp->rq_resp;
     struct nfsd4_compoundargs *argp = rqstp->rq_argp;
     struct nfsd4_op *this = &argp->ops[resp->opcnt - 1];
     struct nfsd4_op *next = &argp->ops[resp->opcnt];
     const struct nfsd4_operation *thisd = OPDESC(this);
     const struct nfsd4_operation *nextd;
 
     /*
      * Most ops check wronsec on our own; only the putfh-like ops
      * have special rules.
      */
     if (!(thisd->op_flags & OP_IS_PUTFH_LIKE))
         return false;
     /*
      * rfc 5661 2.6.3.1.1.6: don't bother erroring out a
      * put-filehandle operation if we're not going to use the
      * result:
      */
     if (argp->opcnt == resp->opcnt)
         return false;
     if (next->opnum == OP_ILLEGAL)
         return false;
     nextd = OPDESC(next);
     /*
      * Rest of 2.6.3.1.1: certain operations will return WRONGSEC
      * errors themselves as necessary; others should check for them
      * now:
      */
     return !(nextd->op_flags & OP_HANDLES_WRONGSEC);
 }
 
 #ifdef CONFIG_NFSD_V4_2_INTER_SSC
 static void
 check_if_stalefh_allowed(struct nfsd4_compoundargs *args)
 {
     struct nfsd4_op *op, *current_op = NULL, *saved_op = NULL;
     struct nfsd4_copy *copy;
     struct nfsd4_putfh *putfh;
     int i;
 
     /* traverse all operation and if it's a COPY compound, mark the
      * source filehandle to skip verification
      */
     for (i = 0; i < args->opcnt; i++) {
         op = &args->ops[i];
         if (op->opnum == OP_PUTFH)
             current_op = op;
         else if (op->opnum == OP_SAVEFH)
             saved_op = current_op;
         else if (op->opnum == OP_RESTOREFH)
             current_op = saved_op;
         else if (op->opnum == OP_COPY) {
             copy = (struct nfsd4_copy *)&op->u;
             if (!saved_op) {
                 op->status = nfserr_nofilehandle;
                 return;
             }
             putfh = (struct nfsd4_putfh *)&saved_op->u;
             if (nfsd4_ssc_is_inter(copy))
                 putfh->no_verify = true;
         }
     }
 }
 #else
 static void
 check_if_stalefh_allowed(struct nfsd4_compoundargs *args)
 {
 }
 #endif
 
 /*
  * COMPOUND call.
  */
 static __be32
 nfsd4_proc_compound(struct svc_rqst *rqstp)
 {
     struct nfsd4_compoundargs *args = rqstp->rq_argp;
     struct nfsd4_compoundres *resp = rqstp->rq_resp;
     struct nfsd4_op *op;
     struct nfsd4_compound_state *cstate = &resp->cstate;
     struct svc_fh *current_fh = &cstate->current_fh;
     struct svc_fh *save_fh = &cstate->save_fh;
     struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
     __be32      status;
 
     resp->xdr = &rqstp->rq_res_stream;
     resp->statusp = resp->xdr->p;
 
     /* reserve space for: NFS status code */
     xdr_reserve_space(resp->xdr, XDR_UNIT);
 
     /* reserve space for: taglen, tag, and opcnt */
     xdr_reserve_space(resp->xdr, XDR_UNIT * 2 + args->taglen);
     resp->taglen = args->taglen;
     resp->tag = args->tag;
     resp->rqstp = rqstp;
     cstate->minorversion = args->minorversion;
     fh_init(current_fh, NFS4_FHSIZE);
     fh_init(save_fh, NFS4_FHSIZE);
 
     /*
      * Don't use the deferral mechanism for NFSv4; compounds make it
      * too hard to avoid non-idempotency problems.
      */
     __clear_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
 
     /*
      * According to RFC3010, this takes precedence over all other errors.
      */
     status = nfserr_minor_vers_mismatch;
     if (nfsd_minorversion(nn, args->minorversion, NFSD_TEST) <= 0)
         goto out;
     status = nfserr_resource;
     if (args->opcnt > NFSD_MAX_OPS_PER_COMPOUND)
         goto out;
 
     status = nfs41_check_op_ordering(args);
     if (status) {
         op = &args->ops[0];
         op->status = status;
         resp->opcnt = 1;
         goto encode_op;
     }
     check_if_stalefh_allowed(args);
 
     rqstp->rq_lease_breaker = (void **)&cstate->clp;
 
     trace_nfsd_compound(rqstp, args->opcnt);
     while (!status && resp->opcnt < args->opcnt) {
         op = &args->ops[resp->opcnt++];
 
         /*
          * The XDR decode routines may have pre-set op->status;
          * for example, if there is a miscellaneous XDR error
          * it will be set to nfserr_bad_xdr.
          */
         if (op->status) {
             if (op->opnum == OP_OPEN)
                 op->status = nfsd4_open_omfg(rqstp, cstate, op);
             goto encode_op;
         }
         if (!current_fh->fh_dentry &&
                 !HAS_FH_FLAG(current_fh, NFSD4_FH_FOREIGN)) {
             if (!(op->opdesc->op_flags & ALLOWED_WITHOUT_FH)) {
                 op->status = nfserr_nofilehandle;
                 goto encode_op;
             }
         } else if (current_fh->fh_export &&
                current_fh->fh_export->ex_fslocs.migrated &&
               !(op->opdesc->op_flags & ALLOWED_ON_ABSENT_FS)) {
             op->status = nfserr_moved;
             goto encode_op;
         }
 
         fh_clear_pre_post_attrs(current_fh);
 
         /* If op is non-idempotent */
         if (op->opdesc->op_flags & OP_MODIFIES_SOMETHING) {
             /*
              * Don't execute this op if we couldn't encode a
              * successful reply:
              */
             u32 plen = op->opdesc->op_rsize_bop(rqstp, op);
             /*
              * Plus if there's another operation, make sure
              * we'll have space to at least encode an error:
              */
             if (resp->opcnt < args->opcnt)
                 plen += COMPOUND_ERR_SLACK_SPACE;
             op->status = nfsd4_check_resp_size(resp, plen);
         }
 
         if (op->status)
             goto encode_op;
 
         if (op->opdesc->op_get_currentstateid)
             op->opdesc->op_get_currentstateid(cstate, &op->u);
         op->status = op->opdesc->op_func(rqstp, cstate, &op->u);
 
         /* Only from SEQUENCE */
         if (cstate->status == nfserr_replay_cache) {
             dprintk("%s NFS4.1 replay from cache\n", __func__);
             status = op->status;
             goto out;
         }
         if (!op->status) {
             if (op->opdesc->op_set_currentstateid)
                 op->opdesc->op_set_currentstateid(cstate, &op->u);
 
             if (op->opdesc->op_flags & OP_CLEAR_STATEID)
                 clear_current_stateid(cstate);
 
             if (current_fh->fh_export &&
                     need_wrongsec_check(rqstp))
                 op->status = check_nfsd_access(current_fh->fh_export, rqstp);
         }
 encode_op:
         if (op->status == nfserr_replay_me) {
             op->replay = &cstate->replay_owner->so_replay;
             nfsd4_encode_replay(resp->xdr, op);
             status = op->status = op->replay->rp_status;
         } else {
             nfsd4_encode_operation(resp, op);
             status = op->status;
         }
 
         trace_nfsd_compound_status(args->opcnt, resp->opcnt, status,
                        nfsd4_op_name(op->opnum));
 
         nfsd4_cstate_clear_replay(cstate);
         nfsd4_increment_op_stats(op->opnum);
     }
 
     fh_put(current_fh);
     fh_put(save_fh);
     BUG_ON(cstate->replay_owner);
 out:
     cstate->status = status;
     /* Reset deferral mechanism for RPC deferrals */
     __set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
     return rpc_success;
 }
 
 #define op_encode_hdr_size      (2)
 #define op_encode_stateid_maxsz     (XDR_QUADLEN(NFS4_STATEID_SIZE))
 #define op_encode_verifier_maxsz    (XDR_QUADLEN(NFS4_VERIFIER_SIZE))
 #define op_encode_change_info_maxsz (5)
 #define nfs4_fattr_bitmap_maxsz     (4)
 
 /* We'll fall back on returning no lockowner if run out of space: */
 #define op_encode_lockowner_maxsz   (0)
 #define op_encode_lock_denied_maxsz (8 + op_encode_lockowner_maxsz)
 
 #define nfs4_owner_maxsz        (1 + XDR_QUADLEN(IDMAP_NAMESZ))
 
 #define op_encode_ace_maxsz     (3 + nfs4_owner_maxsz)
 #define op_encode_delegation_maxsz  (1 + op_encode_stateid_maxsz + 1 + \
                      op_encode_ace_maxsz)
 
 #define op_encode_channel_attrs_maxsz   (6 + 1 + 1)
 
 static inline u32 nfsd4_only_status_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_status_stateid_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + op_encode_stateid_maxsz)* sizeof(__be32);
 }
 
 static inline u32 nfsd4_access_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     /* ac_supported, ac_resp_access */
     return (op_encode_hdr_size + 2)* sizeof(__be32);
 }
 
 static inline u32 nfsd4_commit_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + op_encode_verifier_maxsz) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_create_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + op_encode_change_info_maxsz
         + nfs4_fattr_bitmap_maxsz) * sizeof(__be32);
 }
 
 /*
  * Note since this is an idempotent operation we won't insist on failing
  * the op prematurely if the estimate is too large.  We may turn off splice
  * reads unnecessarily.
  */
 static inline u32 nfsd4_getattr_rsize(struct svc_rqst *rqstp,
                       struct nfsd4_op *op)
 {
     u32 *bmap = op->u.getattr.ga_bmval;
     u32 bmap0 = bmap[0], bmap1 = bmap[1], bmap2 = bmap[2];
     u32 ret = 0;
 
     if (bmap0 & FATTR4_WORD0_ACL)
         return svc_max_payload(rqstp);
     if (bmap0 & FATTR4_WORD0_FS_LOCATIONS)
         return svc_max_payload(rqstp);
 
     if (bmap1 & FATTR4_WORD1_OWNER) {
         ret += IDMAP_NAMESZ + 4;
         bmap1 &= ~FATTR4_WORD1_OWNER;
     }
     if (bmap1 & FATTR4_WORD1_OWNER_GROUP) {
         ret += IDMAP_NAMESZ + 4;
         bmap1 &= ~FATTR4_WORD1_OWNER_GROUP;
     }
     if (bmap0 & FATTR4_WORD0_FILEHANDLE) {
         ret += NFS4_FHSIZE + 4;
         bmap0 &= ~FATTR4_WORD0_FILEHANDLE;
     }
     if (bmap2 & FATTR4_WORD2_SECURITY_LABEL) {
         ret += NFS4_MAXLABELLEN + 12;
         bmap2 &= ~FATTR4_WORD2_SECURITY_LABEL;
     }
     /*
      * Largest of remaining attributes are 16 bytes (e.g.,
      * supported_attributes)
      */
     ret += 16 * (hweight32(bmap0) + hweight32(bmap1) + hweight32(bmap2));
     /* bitmask, length */
     ret += 20;
     return ret;
 }
 
 static inline u32 nfsd4_getfh_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + 1) * sizeof(__be32) + NFS4_FHSIZE;
 }
 
 static inline u32 nfsd4_link_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + op_encode_change_info_maxsz)
         * sizeof(__be32);
 }
 
 static inline u32 nfsd4_lock_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + op_encode_lock_denied_maxsz)
         * sizeof(__be32);
 }
 
 static inline u32 nfsd4_open_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + op_encode_stateid_maxsz
         + op_encode_change_info_maxsz + 1
         + nfs4_fattr_bitmap_maxsz
         + op_encode_delegation_maxsz) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_read_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     u32 maxcount = 0, rlen = 0;
 
     maxcount = svc_max_payload(rqstp);
     rlen = min(op->u.read.rd_length, maxcount);
 
     return (op_encode_hdr_size + 2 + XDR_QUADLEN(rlen)) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_read_plus_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     u32 maxcount = svc_max_payload(rqstp);
     u32 rlen = min(op->u.read.rd_length, maxcount);
     /*
      * If we detect that the file changed during hole encoding, then we
      * recover by encoding the remaining reply as data. This means we need
      * to set aside enough room to encode two data segments.
      */
     u32 seg_len = 2 * (1 + 2 + 1);
 
     return (op_encode_hdr_size + 2 + seg_len + XDR_QUADLEN(rlen)) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_readdir_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     u32 maxcount = 0, rlen = 0;
 
     maxcount = svc_max_payload(rqstp);
     rlen = min(op->u.readdir.rd_maxcount, maxcount);
 
     return (op_encode_hdr_size + op_encode_verifier_maxsz +
         XDR_QUADLEN(rlen)) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_readlink_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + 1) * sizeof(__be32) + PAGE_SIZE;
 }
 
 static inline u32 nfsd4_remove_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + op_encode_change_info_maxsz)
         * sizeof(__be32);
 }
 
 static inline u32 nfsd4_rename_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + op_encode_change_info_maxsz
         + op_encode_change_info_maxsz) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_sequence_rsize(struct svc_rqst *rqstp,
                        struct nfsd4_op *op)
 {
     return (op_encode_hdr_size
         + XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + 5) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_test_stateid_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + 1 + op->u.test_stateid.ts_num_ids)
         * sizeof(__be32);
 }
 
 static inline u32 nfsd4_setattr_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + nfs4_fattr_bitmap_maxsz) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_secinfo_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + RPC_AUTH_MAXFLAVOR *
         (4 + XDR_QUADLEN(GSS_OID_MAX_LEN))) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_setclientid_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + 2 + XDR_QUADLEN(NFS4_VERIFIER_SIZE)) *
                                 sizeof(__be32);
 }
 
 static inline u32 nfsd4_write_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + 2 + op_encode_verifier_maxsz) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_exchange_id_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + 2 + 1 + /* eir_clientid, eir_sequenceid */\
         1 + 1 + /* eir_flags, spr_how */\
         4 + /* spo_must_enforce & _allow with bitmap */\
         2 + /*eir_server_owner.so_minor_id */\
         /* eir_server_owner.so_major_id<> */\
         XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + 1 +\
         /* eir_server_scope<> */\
         XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + 1 +\
         1 + /* eir_server_impl_id array length */\
         0 /* ignored eir_server_impl_id contents */) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_bind_conn_to_session_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + \
         XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + /* bctsr_sessid */\
         2 /* bctsr_dir, use_conn_in_rdma_mode */) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_create_session_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + \
         XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + /* sessionid */\
         2 + /* csr_sequence, csr_flags */\
         op_encode_channel_attrs_maxsz + \
         op_encode_channel_attrs_maxsz) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_copy_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size +
         1 /* wr_callback */ +
         op_encode_stateid_maxsz /* wr_callback */ +
         2 /* wr_count */ +
         1 /* wr_committed */ +
         op_encode_verifier_maxsz +
         1 /* cr_consecutive */ +
         1 /* cr_synchronous */) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_offload_status_rsize(struct svc_rqst *rqstp,
                          struct nfsd4_op *op)
 {
     return (op_encode_hdr_size +
         2 /* osr_count */ +
         1 /* osr_complete<1> optional 0 for now */) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_copy_notify_rsize(struct svc_rqst *rqstp,
                     struct nfsd4_op *op)
 {
     return (op_encode_hdr_size +
         3 /* cnr_lease_time */ +
         1 /* We support one cnr_source_server */ +
         1 /* cnr_stateid seq */ +
         op_encode_stateid_maxsz /* cnr_stateid */ +
         1 /* num cnr_source_server*/ +
         1 /* nl4_type */ +
         1 /* nl4 size */ +
         XDR_QUADLEN(NFS4_OPAQUE_LIMIT) /*nl4_loc + nl4_loc_sz */)
         * sizeof(__be32);
 }
 
 #ifdef CONFIG_NFSD_PNFS
 static inline u32 nfsd4_getdeviceinfo_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     u32 maxcount = 0, rlen = 0;
 
     maxcount = svc_max_payload(rqstp);
     rlen = min(op->u.getdeviceinfo.gd_maxcount, maxcount);
 
     return (op_encode_hdr_size +
         1 /* gd_layout_type*/ +
         XDR_QUADLEN(rlen) +
         2 /* gd_notify_types */) * sizeof(__be32);
 }
 
 /*
  * At this stage we don't really know what layout driver will handle the request,
  * so we need to define an arbitrary upper bound here.
  */
 #define MAX_LAYOUT_SIZE     128
 static inline u32 nfsd4_layoutget_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size +
         1 /* logr_return_on_close */ +
         op_encode_stateid_maxsz +
         1 /* nr of layouts */ +
         MAX_LAYOUT_SIZE) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_layoutcommit_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size +
         1 /* locr_newsize */ +
         2 /* ns_size */) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_layoutreturn_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size +
         1 /* lrs_stateid */ +
         op_encode_stateid_maxsz) * sizeof(__be32);
 }
 #endif /* CONFIG_NFSD_PNFS */
 
 
 static inline u32 nfsd4_seek_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + 3) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_getxattr_rsize(struct svc_rqst *rqstp,
                        struct nfsd4_op *op)
 {
     u32 maxcount, rlen;
 
     maxcount = svc_max_payload(rqstp);
     rlen = min_t(u32, XATTR_SIZE_MAX, maxcount);
 
     return (op_encode_hdr_size + 1 + XDR_QUADLEN(rlen)) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_setxattr_rsize(struct svc_rqst *rqstp,
                        struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + op_encode_change_info_maxsz)
         * sizeof(__be32);
 }
 static inline u32 nfsd4_listxattrs_rsize(struct svc_rqst *rqstp,
                      struct nfsd4_op *op)
 {
     u32 maxcount, rlen;
 
     maxcount = svc_max_payload(rqstp);
     rlen = min(op->u.listxattrs.lsxa_maxcount, maxcount);
 
     return (op_encode_hdr_size + 4 + XDR_QUADLEN(rlen)) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_removexattr_rsize(struct svc_rqst *rqstp,
                       struct nfsd4_op *op)
 {
     return (op_encode_hdr_size + op_encode_change_info_maxsz)
         * sizeof(__be32);
 }
 
 
 static const struct nfsd4_operation nfsd4_ops[] = {
     [OP_ACCESS] = {
         .op_func = nfsd4_access,
         .op_name = "OP_ACCESS",
         .op_rsize_bop = nfsd4_access_rsize,
     },
     [OP_CLOSE] = {
         .op_func = nfsd4_close,
         .op_flags = OP_MODIFIES_SOMETHING,
         .op_name = "OP_CLOSE",
         .op_rsize_bop = nfsd4_status_stateid_rsize,
         .op_get_currentstateid = nfsd4_get_closestateid,
         .op_set_currentstateid = nfsd4_set_closestateid,
     },
     [OP_COMMIT] = {
         .op_func = nfsd4_commit,
         .op_flags = OP_MODIFIES_SOMETHING,
         .op_name = "OP_COMMIT",
         .op_rsize_bop = nfsd4_commit_rsize,
     },
     [OP_CREATE] = {
         .op_func = nfsd4_create,
         .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME | OP_CLEAR_STATEID,
         .op_name = "OP_CREATE",
         .op_rsize_bop = nfsd4_create_rsize,
     },
     [OP_DELEGRETURN] = {
         .op_func = nfsd4_delegreturn,
         .op_flags = OP_MODIFIES_SOMETHING,
         .op_name = "OP_DELEGRETURN",
         .op_rsize_bop = nfsd4_only_status_rsize,
         .op_get_currentstateid = nfsd4_get_delegreturnstateid,
     },
     [OP_GETATTR] = {
         .op_func = nfsd4_getattr,
         .op_flags = ALLOWED_ON_ABSENT_FS,
         .op_rsize_bop = nfsd4_getattr_rsize,
         .op_name = "OP_GETATTR",
     },
     [OP_GETFH] = {
         .op_func = nfsd4_getfh,
         .op_name = "OP_GETFH",
         .op_rsize_bop = nfsd4_getfh_rsize,
     },
     [OP_LINK] = {
         .op_func = nfsd4_link,
         .op_flags = ALLOWED_ON_ABSENT_FS | OP_MODIFIES_SOMETHING
                 | OP_CACHEME,
         .op_name = "OP_LINK",
         .op_rsize_bop = nfsd4_link_rsize,
     },
     [OP_LOCK] = {
         .op_func = nfsd4_lock,
         .op_flags = OP_MODIFIES_SOMETHING |
                 OP_NONTRIVIAL_ERROR_ENCODE,
         .op_name = "OP_LOCK",
         .op_rsize_bop = nfsd4_lock_rsize,
         .op_set_currentstateid = nfsd4_set_lockstateid,
     },
     [OP_LOCKT] = {
         .op_func = nfsd4_lockt,
         .op_flags = OP_NONTRIVIAL_ERROR_ENCODE,
         .op_name = "OP_LOCKT",
         .op_rsize_bop = nfsd4_lock_rsize,
     },
     [OP_LOCKU] = {
         .op_func = nfsd4_locku,
         .op_flags = OP_MODIFIES_SOMETHING,
         .op_name = "OP_LOCKU",
         .op_rsize_bop = nfsd4_status_stateid_rsize,
         .op_get_currentstateid = nfsd4_get_lockustateid,
     },
     [OP_LOOKUP] = {
         .op_func = nfsd4_lookup,
         .op_flags = OP_HANDLES_WRONGSEC | OP_CLEAR_STATEID,
         .op_name = "OP_LOOKUP",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_LOOKUPP] = {
         .op_func = nfsd4_lookupp,
         .op_flags = OP_HANDLES_WRONGSEC | OP_CLEAR_STATEID,
         .op_name = "OP_LOOKUPP",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_NVERIFY] = {
         .op_func = nfsd4_nverify,
         .op_name = "OP_NVERIFY",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_OPEN] = {
         .op_func = nfsd4_open,
         .op_flags = OP_HANDLES_WRONGSEC | OP_MODIFIES_SOMETHING,
         .op_name = "OP_OPEN",
         .op_rsize_bop = nfsd4_open_rsize,
         .op_set_currentstateid = nfsd4_set_openstateid,
     },
     [OP_OPEN_CONFIRM] = {
         .op_func = nfsd4_open_confirm,
         .op_flags = OP_MODIFIES_SOMETHING,
         .op_name = "OP_OPEN_CONFIRM",
         .op_rsize_bop = nfsd4_status_stateid_rsize,
     },
     [OP_OPEN_DOWNGRADE] = {
         .op_func = nfsd4_open_downgrade,
         .op_flags = OP_MODIFIES_SOMETHING,
         .op_name = "OP_OPEN_DOWNGRADE",
         .op_rsize_bop = nfsd4_status_stateid_rsize,
         .op_get_currentstateid = nfsd4_get_opendowngradestateid,
         .op_set_currentstateid = nfsd4_set_opendowngradestateid,
     },
     [OP_PUTFH] = {
         .op_func = nfsd4_putfh,
         .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
                 | OP_IS_PUTFH_LIKE | OP_CLEAR_STATEID,
         .op_name = "OP_PUTFH",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_PUTPUBFH] = {
         .op_func = nfsd4_putrootfh,
         .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
                 | OP_IS_PUTFH_LIKE | OP_CLEAR_STATEID,
         .op_name = "OP_PUTPUBFH",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_PUTROOTFH] = {
         .op_func = nfsd4_putrootfh,
         .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
                 | OP_IS_PUTFH_LIKE | OP_CLEAR_STATEID,
         .op_name = "OP_PUTROOTFH",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_READ] = {
         .op_func = nfsd4_read,
         .op_release = nfsd4_read_release,
         .op_name = "OP_READ",
         .op_rsize_bop = nfsd4_read_rsize,
         .op_get_currentstateid = nfsd4_get_readstateid,
     },
     [OP_READDIR] = {
         .op_func = nfsd4_readdir,
         .op_name = "OP_READDIR",
         .op_rsize_bop = nfsd4_readdir_rsize,
     },
     [OP_READLINK] = {
         .op_func = nfsd4_readlink,
         .op_name = "OP_READLINK",
         .op_rsize_bop = nfsd4_readlink_rsize,
     },
     [OP_REMOVE] = {
         .op_func = nfsd4_remove,
         .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
         .op_name = "OP_REMOVE",
         .op_rsize_bop = nfsd4_remove_rsize,
     },
     [OP_RENAME] = {
         .op_func = nfsd4_rename,
         .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
         .op_name = "OP_RENAME",
         .op_rsize_bop = nfsd4_rename_rsize,
     },
     [OP_RENEW] = {
         .op_func = nfsd4_renew,
         .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
                 | OP_MODIFIES_SOMETHING,
         .op_name = "OP_RENEW",
         .op_rsize_bop = nfsd4_only_status_rsize,
 
     },
     [OP_RESTOREFH] = {
         .op_func = nfsd4_restorefh,
         .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
                 | OP_IS_PUTFH_LIKE | OP_MODIFIES_SOMETHING,
         .op_name = "OP_RESTOREFH",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_SAVEFH] = {
         .op_func = nfsd4_savefh,
         .op_flags = OP_HANDLES_WRONGSEC | OP_MODIFIES_SOMETHING,
         .op_name = "OP_SAVEFH",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_SECINFO] = {
         .op_func = nfsd4_secinfo,
         .op_release = nfsd4_secinfo_release,
         .op_flags = OP_HANDLES_WRONGSEC,
         .op_name = "OP_SECINFO",
         .op_rsize_bop = nfsd4_secinfo_rsize,
     },
     [OP_SETATTR] = {
         .op_func = nfsd4_setattr,
         .op_name = "OP_SETATTR",
         .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME
                 | OP_NONTRIVIAL_ERROR_ENCODE,
         .op_rsize_bop = nfsd4_setattr_rsize,
         .op_get_currentstateid = nfsd4_get_setattrstateid,
     },
     [OP_SETCLIENTID] = {
         .op_func = nfsd4_setclientid,
         .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
                 | OP_MODIFIES_SOMETHING | OP_CACHEME
                 | OP_NONTRIVIAL_ERROR_ENCODE,
         .op_name = "OP_SETCLIENTID",
         .op_rsize_bop = nfsd4_setclientid_rsize,
     },
     [OP_SETCLIENTID_CONFIRM] = {
         .op_func = nfsd4_setclientid_confirm,
         .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
                 | OP_MODIFIES_SOMETHING | OP_CACHEME,
         .op_name = "OP_SETCLIENTID_CONFIRM",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_VERIFY] = {
         .op_func = nfsd4_verify,
         .op_name = "OP_VERIFY",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_WRITE] = {
         .op_func = nfsd4_write,
         .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
         .op_name = "OP_WRITE",
         .op_rsize_bop = nfsd4_write_rsize,
         .op_get_currentstateid = nfsd4_get_writestateid,
     },
     [OP_RELEASE_LOCKOWNER] = {
         .op_func = nfsd4_release_lockowner,
         .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
                 | OP_MODIFIES_SOMETHING,
         .op_name = "OP_RELEASE_LOCKOWNER",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
 
     /* NFSv4.1 operations */
     [OP_EXCHANGE_ID] = {
         .op_func = nfsd4_exchange_id,
         .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
                 | OP_MODIFIES_SOMETHING,
         .op_name = "OP_EXCHANGE_ID",
         .op_rsize_bop = nfsd4_exchange_id_rsize,
     },
     [OP_BACKCHANNEL_CTL] = {
         .op_func = nfsd4_backchannel_ctl,
         .op_flags = ALLOWED_WITHOUT_FH | OP_MODIFIES_SOMETHING,
         .op_name = "OP_BACKCHANNEL_CTL",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_BIND_CONN_TO_SESSION] = {
         .op_func = nfsd4_bind_conn_to_session,
         .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
                 | OP_MODIFIES_SOMETHING,
         .op_name = "OP_BIND_CONN_TO_SESSION",
         .op_rsize_bop = nfsd4_bind_conn_to_session_rsize,
     },
     [OP_CREATE_SESSION] = {
         .op_func = nfsd4_create_session,
         .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
                 | OP_MODIFIES_SOMETHING,
         .op_name = "OP_CREATE_SESSION",
         .op_rsize_bop = nfsd4_create_session_rsize,
     },
     [OP_DESTROY_SESSION] = {
         .op_func = nfsd4_destroy_session,
         .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
                 | OP_MODIFIES_SOMETHING,
         .op_name = "OP_DESTROY_SESSION",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_SEQUENCE] = {
         .op_func = nfsd4_sequence,
         .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP,
         .op_name = "OP_SEQUENCE",
         .op_rsize_bop = nfsd4_sequence_rsize,
     },
     [OP_DESTROY_CLIENTID] = {
         .op_func = nfsd4_destroy_clientid,
         .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
                 | OP_MODIFIES_SOMETHING,
         .op_name = "OP_DESTROY_CLIENTID",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_RECLAIM_COMPLETE] = {
         .op_func = nfsd4_reclaim_complete,
         .op_flags = ALLOWED_WITHOUT_FH | OP_MODIFIES_SOMETHING,
         .op_name = "OP_RECLAIM_COMPLETE",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_SECINFO_NO_NAME] = {
         .op_func = nfsd4_secinfo_no_name,
         .op_release = nfsd4_secinfo_no_name_release,
         .op_flags = OP_HANDLES_WRONGSEC,
         .op_name = "OP_SECINFO_NO_NAME",
         .op_rsize_bop = nfsd4_secinfo_rsize,
     },
     [OP_TEST_STATEID] = {
         .op_func = nfsd4_test_stateid,
         .op_flags = ALLOWED_WITHOUT_FH,
         .op_name = "OP_TEST_STATEID",
         .op_rsize_bop = nfsd4_test_stateid_rsize,
     },
     [OP_FREE_STATEID] = {
         .op_func = nfsd4_free_stateid,
         .op_flags = ALLOWED_WITHOUT_FH | OP_MODIFIES_SOMETHING,
         .op_name = "OP_FREE_STATEID",
         .op_get_currentstateid = nfsd4_get_freestateid,
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
 #ifdef CONFIG_NFSD_PNFS
     [OP_GETDEVICEINFO] = {
         .op_func = nfsd4_getdeviceinfo,
         .op_release = nfsd4_getdeviceinfo_release,
         .op_flags = ALLOWED_WITHOUT_FH,
         .op_name = "OP_GETDEVICEINFO",
         .op_rsize_bop = nfsd4_getdeviceinfo_rsize,
     },
     [OP_LAYOUTGET] = {
         .op_func = nfsd4_layoutget,
         .op_release = nfsd4_layoutget_release,
         .op_flags = OP_MODIFIES_SOMETHING,
         .op_name = "OP_LAYOUTGET",
         .op_rsize_bop = nfsd4_layoutget_rsize,
     },
     [OP_LAYOUTCOMMIT] = {
         .op_func = nfsd4_layoutcommit,
         .op_flags = OP_MODIFIES_SOMETHING,
         .op_name = "OP_LAYOUTCOMMIT",
         .op_rsize_bop = nfsd4_layoutcommit_rsize,
     },
     [OP_LAYOUTRETURN] = {
         .op_func = nfsd4_layoutreturn,
         .op_flags = OP_MODIFIES_SOMETHING,
         .op_name = "OP_LAYOUTRETURN",
         .op_rsize_bop = nfsd4_layoutreturn_rsize,
     },
 #endif /* CONFIG_NFSD_PNFS */
 
     /* NFSv4.2 operations */
     [OP_ALLOCATE] = {
         .op_func = nfsd4_allocate,
         .op_flags = OP_MODIFIES_SOMETHING,
         .op_name = "OP_ALLOCATE",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_DEALLOCATE] = {
         .op_func = nfsd4_deallocate,
         .op_flags = OP_MODIFIES_SOMETHING,
         .op_name = "OP_DEALLOCATE",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_CLONE] = {
         .op_func = nfsd4_clone,
         .op_flags = OP_MODIFIES_SOMETHING,
         .op_name = "OP_CLONE",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_COPY] = {
         .op_func = nfsd4_copy,
         .op_flags = OP_MODIFIES_SOMETHING,
         .op_name = "OP_COPY",
         .op_rsize_bop = nfsd4_copy_rsize,
     },
     [OP_READ_PLUS] = {
         .op_func = nfsd4_read,
         .op_release = nfsd4_read_release,
         .op_name = "OP_READ_PLUS",
         .op_rsize_bop = nfsd4_read_plus_rsize,
         .op_get_currentstateid = nfsd4_get_readstateid,
     },
     [OP_SEEK] = {
         .op_func = nfsd4_seek,
         .op_name = "OP_SEEK",
         .op_rsize_bop = nfsd4_seek_rsize,
     },
     [OP_OFFLOAD_STATUS] = {
         .op_func = nfsd4_offload_status,
         .op_name = "OP_OFFLOAD_STATUS",
         .op_rsize_bop = nfsd4_offload_status_rsize,
     },
     [OP_OFFLOAD_CANCEL] = {
         .op_func = nfsd4_offload_cancel,
         .op_flags = OP_MODIFIES_SOMETHING,
         .op_name = "OP_OFFLOAD_CANCEL",
         .op_rsize_bop = nfsd4_only_status_rsize,
     },
     [OP_COPY_NOTIFY] = {
         .op_func = nfsd4_copy_notify,
         .op_flags = OP_MODIFIES_SOMETHING,
         .op_name = "OP_COPY_NOTIFY",
         .op_rsize_bop = nfsd4_copy_notify_rsize,
     },
     [OP_GETXATTR] = {
         .op_func = nfsd4_getxattr,
         .op_name = "OP_GETXATTR",
         .op_rsize_bop = nfsd4_getxattr_rsize,
     },
     [OP_SETXATTR] = {
         .op_func = nfsd4_setxattr,
         .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
         .op_name = "OP_SETXATTR",
         .op_rsize_bop = nfsd4_setxattr_rsize,
     },
     [OP_LISTXATTRS] = {
         .op_func = nfsd4_listxattrs,
         .op_name = "OP_LISTXATTRS",
         .op_rsize_bop = nfsd4_listxattrs_rsize,
     },
     [OP_REMOVEXATTR] = {
         .op_func = nfsd4_removexattr,
         .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
         .op_name = "OP_REMOVEXATTR",
         .op_rsize_bop = nfsd4_removexattr_rsize,
     },
 };
 
 /**
  * nfsd4_spo_must_allow - Determine if the compound op contains an
  * operation that is allowed to be sent with machine credentials
  *
  * @rqstp: a pointer to the struct svc_rqst
  *
  * Checks to see if the compound contains a spo_must_allow op
  * and confirms that it was sent with the proper machine creds.
  */
 
 bool nfsd4_spo_must_allow(struct svc_rqst *rqstp)
 {
     struct nfsd4_compoundres *resp = rqstp->rq_resp;
     struct nfsd4_compoundargs *argp = rqstp->rq_argp;
     struct nfsd4_op *this;
     struct nfsd4_compound_state *cstate = &resp->cstate;
     struct nfs4_op_map *allow = &cstate->clp->cl_spo_must_allow;
     u32 opiter;
 
     if (!cstate->minorversion)
         return false;
 
     if (cstate->spo_must_allowed)
         return true;
 
     opiter = resp->opcnt;
     while (opiter < argp->opcnt) {
         this = &argp->ops[opiter++];
         if (test_bit(this->opnum, allow->u.longs) &&
             cstate->clp->cl_mach_cred &&
             nfsd4_mach_creds_match(cstate->clp, rqstp)) {
             cstate->spo_must_allowed = true;
             return true;
         }
     }
     cstate->spo_must_allowed = false;
     return false;
 }
 
 int nfsd4_max_reply(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
     if (op->opnum == OP_ILLEGAL || op->status == nfserr_notsupp)
         return op_encode_hdr_size * sizeof(__be32);
 
     BUG_ON(OPDESC(op)->op_rsize_bop == NULL);
     return OPDESC(op)->op_rsize_bop(rqstp, op);
 }
 
 void warn_on_nonidempotent_op(struct nfsd4_op *op)
 {
     if (OPDESC(op)->op_flags & OP_MODIFIES_SOMETHING) {
         pr_err("unable to encode reply to nonidempotent op %u (%s)\n",
             op->opnum, nfsd4_op_name(op->opnum));
         WARN_ON_ONCE(1);
     }
 }
 
 static const char *nfsd4_op_name(unsigned opnum)
 {
     if (opnum < ARRAY_SIZE(nfsd4_ops))
         return nfsd4_ops[opnum].op_name;
     return "unknown_operation";
 }
 
 static const struct svc_procedure nfsd_procedures4[2] = {
     [NFSPROC4_NULL] = {
         .pc_func = nfsd4_proc_null,
         .pc_decode = nfssvc_decode_voidarg,
         .pc_encode = nfssvc_encode_voidres,
         .pc_argsize = sizeof(struct nfsd_voidargs),
         .pc_ressize = sizeof(struct nfsd_voidres),
         .pc_cachetype = RC_NOCACHE,
         .pc_xdrressize = 1,
         .pc_name = "NULL",
     },
     [NFSPROC4_COMPOUND] = {
         .pc_func = nfsd4_proc_compound,
         .pc_decode = nfs4svc_decode_compoundargs,
         .pc_encode = nfs4svc_encode_compoundres,
         .pc_argsize = sizeof(struct nfsd4_compoundargs),
         .pc_ressize = sizeof(struct nfsd4_compoundres),
         .pc_release = nfsd4_release_compoundargs,
         .pc_cachetype = RC_NOCACHE,
         .pc_xdrressize = NFSD_BUFSIZE/4,
         .pc_name = "COMPOUND",
     },
 };
 
 static unsigned int nfsd_count3[ARRAY_SIZE(nfsd_procedures4)];
 const struct svc_version nfsd_version4 = {
     .vs_vers        = 4,
     .vs_nproc       = 2,
     .vs_proc        = nfsd_procedures4,
     .vs_count       = nfsd_count3,
     .vs_dispatch        = nfsd_dispatch,
     .vs_xdrsize     = NFS4_SVC_XDRSIZE,
     .vs_rpcb_optnl      = true,
     .vs_need_cong_ctrl  = true,
 };