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nfs4proc.c

/*
 *  fs/nfs/nfs4proc.c
 *
 *  Client-side procedure declarations 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/mm.h>
#include <linux/utsname.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs.h>
#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>
#include <linux/smp_lock.h>
#include <linux/namei.h>
#include <linux/mount.h>

#include "nfs4_fs.h"
#include "delegation.h"
#include "iostat.h"

#define NFSDBG_FACILITY       NFSDBG_PROC

#define NFS4_POLL_RETRY_MIN   (1*HZ)
#define NFS4_POLL_RETRY_MAX   (15*HZ)

struct nfs4_opendata;
static int _nfs4_proc_open(struct nfs4_opendata *data);
static int nfs4_do_fsinfo(struct nfs_server *, struct nfs_fh *, struct nfs_fsinfo *);
static int nfs4_async_handle_error(struct rpc_task *, const struct nfs_server *);
static int _nfs4_proc_access(struct inode *inode, struct nfs_access_entry *entry);
static int nfs4_handle_exception(const struct nfs_server *server, int errorcode, struct nfs4_exception *exception);
static int nfs4_wait_clnt_recover(struct rpc_clnt *clnt, struct nfs4_client *clp);

/* Prevent leaks of NFSv4 errors into userland */
int nfs4_map_errors(int err)
{
      if (err < -1000) {
            dprintk("%s could not handle NFSv4 error %d\n",
                        __FUNCTION__, -err);
            return -EIO;
      }
      return err;
}

/*
 * This is our standard bitmap for GETATTR requests.
 */
const u32 nfs4_fattr_bitmap[2] = {
      FATTR4_WORD0_TYPE
      | FATTR4_WORD0_CHANGE
      | FATTR4_WORD0_SIZE
      | FATTR4_WORD0_FSID
      | FATTR4_WORD0_FILEID,
      FATTR4_WORD1_MODE
      | FATTR4_WORD1_NUMLINKS
      | FATTR4_WORD1_OWNER
      | FATTR4_WORD1_OWNER_GROUP
      | FATTR4_WORD1_RAWDEV
      | FATTR4_WORD1_SPACE_USED
      | FATTR4_WORD1_TIME_ACCESS
      | FATTR4_WORD1_TIME_METADATA
      | FATTR4_WORD1_TIME_MODIFY
};

const u32 nfs4_statfs_bitmap[2] = {
      FATTR4_WORD0_FILES_AVAIL
      | FATTR4_WORD0_FILES_FREE
      | FATTR4_WORD0_FILES_TOTAL,
      FATTR4_WORD1_SPACE_AVAIL
      | FATTR4_WORD1_SPACE_FREE
      | FATTR4_WORD1_SPACE_TOTAL
};

const u32 nfs4_pathconf_bitmap[2] = {
      FATTR4_WORD0_MAXLINK
      | FATTR4_WORD0_MAXNAME,
      0
};

const u32 nfs4_fsinfo_bitmap[2] = { FATTR4_WORD0_MAXFILESIZE
                  | FATTR4_WORD0_MAXREAD
                  | FATTR4_WORD0_MAXWRITE
                  | FATTR4_WORD0_LEASE_TIME,
                  0
};

const u32 nfs4_fs_locations_bitmap[2] = {
      FATTR4_WORD0_TYPE
      | FATTR4_WORD0_CHANGE
      | FATTR4_WORD0_SIZE
      | FATTR4_WORD0_FSID
      | FATTR4_WORD0_FILEID
      | FATTR4_WORD0_FS_LOCATIONS,
      FATTR4_WORD1_MODE
      | FATTR4_WORD1_NUMLINKS
      | FATTR4_WORD1_OWNER
      | FATTR4_WORD1_OWNER_GROUP
      | FATTR4_WORD1_RAWDEV
      | FATTR4_WORD1_SPACE_USED
      | FATTR4_WORD1_TIME_ACCESS
      | FATTR4_WORD1_TIME_METADATA
      | FATTR4_WORD1_TIME_MODIFY
      | FATTR4_WORD1_MOUNTED_ON_FILEID
};

static void nfs4_setup_readdir(u64 cookie, u32 *verifier, struct dentry *dentry,
            struct nfs4_readdir_arg *readdir)
{
      u32 *start, *p;

      BUG_ON(readdir->count < 80);
      if (cookie > 2) {
            readdir->cookie = cookie;
            memcpy(&readdir->verifier, verifier, sizeof(readdir->verifier));
            return;
      }

      readdir->cookie = 0;
      memset(&readdir->verifier, 0, sizeof(readdir->verifier));
      if (cookie == 2)
            return;
      
      /*
       * NFSv4 servers do not return entries for '.' and '..'
       * Therefore, we fake these entries here.  We let '.'
       * have cookie 0 and '..' have cookie 1.  Note that
       * when talking to the server, we always send cookie 0
       * instead of 1 or 2.
       */
      start = p = (u32 *)kmap_atomic(*readdir->pages, KM_USER0);
      
      if (cookie == 0) {
            *p++ = xdr_one;                                  /* next */
            *p++ = xdr_zero;                   /* cookie, first word */
            *p++ = xdr_one;                   /* cookie, second word */
            *p++ = xdr_one;                             /* entry len */
            memcpy(p, ".\0\0\0", 4);                        /* entry */
            p++;
            *p++ = xdr_one;                         /* bitmap length */
            *p++ = htonl(FATTR4_WORD0_FILEID);             /* bitmap */
            *p++ = htonl(8);              /* attribute buffer length */
            p = xdr_encode_hyper(p, dentry->d_inode->i_ino);
      }
      
      *p++ = xdr_one;                                  /* next */
      *p++ = xdr_zero;                   /* cookie, first word */
      *p++ = xdr_two;                   /* cookie, second word */
      *p++ = xdr_two;                             /* entry len */
      memcpy(p, "..\0\0", 4);                         /* entry */
      p++;
      *p++ = xdr_one;                         /* bitmap length */
      *p++ = htonl(FATTR4_WORD0_FILEID);             /* bitmap */
      *p++ = htonl(8);              /* attribute buffer length */
      p = xdr_encode_hyper(p, dentry->d_parent->d_inode->i_ino);

      readdir->pgbase = (char *)p - (char *)start;
      readdir->count -= readdir->pgbase;
      kunmap_atomic(start, KM_USER0);
}

static void renew_lease(const struct nfs_server *server, unsigned long timestamp)
{
      struct nfs4_client *clp = server->nfs4_state;
      spin_lock(&clp->cl_lock);
      if (time_before(clp->cl_last_renewal,timestamp))
            clp->cl_last_renewal = timestamp;
      spin_unlock(&clp->cl_lock);
}

static void update_changeattr(struct inode *dir, struct nfs4_change_info *cinfo)
{
      struct nfs_inode *nfsi = NFS_I(dir);

      spin_lock(&dir->i_lock);
      nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_DATA;
      if (cinfo->before == nfsi->change_attr && cinfo->atomic)
            nfsi->change_attr = cinfo->after;
      spin_unlock(&dir->i_lock);
}

struct nfs4_opendata {
      atomic_t count;
      struct nfs_openargs o_arg;
      struct nfs_openres o_res;
      struct nfs_open_confirmargs c_arg;
      struct nfs_open_confirmres c_res;
      struct nfs_fattr f_attr;
      struct nfs_fattr dir_attr;
      struct dentry *dentry;
      struct dentry *dir;
      struct nfs4_state_owner *owner;
      struct iattr attrs;
      unsigned long timestamp;
      int rpc_status;
      int cancelled;
};

static struct nfs4_opendata *nfs4_opendata_alloc(struct dentry *dentry,
            struct nfs4_state_owner *sp, int flags,
            const struct iattr *attrs)
{
      struct dentry *parent = dget_parent(dentry);
      struct inode *dir = parent->d_inode;
      struct nfs_server *server = NFS_SERVER(dir);
      struct nfs4_opendata *p;

      p = kzalloc(sizeof(*p), GFP_KERNEL);
      if (p == NULL)
            goto err;
      p->o_arg.seqid = nfs_alloc_seqid(&sp->so_seqid);
      if (p->o_arg.seqid == NULL)
            goto err_free;
      atomic_set(&p->count, 1);
      p->dentry = dget(dentry);
      p->dir = parent;
      p->owner = sp;
      atomic_inc(&sp->so_count);
      p->o_arg.fh = NFS_FH(dir);
      p->o_arg.open_flags = flags,
      p->o_arg.clientid = server->nfs4_state->cl_clientid;
      p->o_arg.id = sp->so_id;
      p->o_arg.name = &dentry->d_name;
      p->o_arg.server = server;
      p->o_arg.bitmask = server->attr_bitmask;
      p->o_arg.claim = NFS4_OPEN_CLAIM_NULL;
      p->o_res.f_attr = &p->f_attr;
      p->o_res.dir_attr = &p->dir_attr;
      p->o_res.server = server;
      nfs_fattr_init(&p->f_attr);
      nfs_fattr_init(&p->dir_attr);
      if (flags & O_EXCL) {
            u32 *s = (u32 *) p->o_arg.u.verifier.data;
            s[0] = jiffies;
            s[1] = current->pid;
      } else if (flags & O_CREAT) {
            p->o_arg.u.attrs = &p->attrs;
            memcpy(&p->attrs, attrs, sizeof(p->attrs));
      }
      p->c_arg.fh = &p->o_res.fh;
      p->c_arg.stateid = &p->o_res.stateid;
      p->c_arg.seqid = p->o_arg.seqid;
      return p;
err_free:
      kfree(p);
err:
      dput(parent);
      return NULL;
}

static void nfs4_opendata_free(struct nfs4_opendata *p)
{
      if (p != NULL && atomic_dec_and_test(&p->count)) {
            nfs_free_seqid(p->o_arg.seqid);
            nfs4_put_state_owner(p->owner);
            dput(p->dir);
            dput(p->dentry);
            kfree(p);
      }
}

/* Helper for asynchronous RPC calls */
static int nfs4_call_async(struct rpc_clnt *clnt,
            const struct rpc_call_ops *tk_ops, void *calldata)
{
      struct rpc_task *task;

      if (!(task = rpc_new_task(clnt, RPC_TASK_ASYNC, tk_ops, calldata)))
            return -ENOMEM;
      rpc_execute(task);
      return 0;
}

static int nfs4_wait_for_completion_rpc_task(struct rpc_task *task)
{
      sigset_t oldset;
      int ret;

      rpc_clnt_sigmask(task->tk_client, &oldset);
      ret = rpc_wait_for_completion_task(task);
      rpc_clnt_sigunmask(task->tk_client, &oldset);
      return ret;
}

static inline void update_open_stateflags(struct nfs4_state *state, mode_t open_flags)
{
      switch (open_flags) {
            case FMODE_WRITE:
                  state->n_wronly++;
                  break;
            case FMODE_READ:
                  state->n_rdonly++;
                  break;
            case FMODE_READ|FMODE_WRITE:
                  state->n_rdwr++;
      }
}

static void update_open_stateid(struct nfs4_state *state, nfs4_stateid *stateid, int open_flags)
{
      struct inode *inode = state->inode;

      open_flags &= (FMODE_READ|FMODE_WRITE);
      /* Protect against nfs4_find_state_byowner() */
      spin_lock(&state->owner->so_lock);
      spin_lock(&inode->i_lock);
      memcpy(&state->stateid, stateid, sizeof(state->stateid));
      update_open_stateflags(state, open_flags);
      nfs4_state_set_mode_locked(state, state->state | open_flags);
      spin_unlock(&inode->i_lock);
      spin_unlock(&state->owner->so_lock);
}

static struct nfs4_state *nfs4_opendata_to_nfs4_state(struct nfs4_opendata *data)
{
      struct inode *inode;
      struct nfs4_state *state = NULL;

      if (!(data->f_attr.valid & NFS_ATTR_FATTR))
            goto out;
      inode = nfs_fhget(data->dir->d_sb, &data->o_res.fh, &data->f_attr);
      if (IS_ERR(inode))
            goto out;
      state = nfs4_get_open_state(inode, data->owner);
      if (state == NULL)
            goto put_inode;
      update_open_stateid(state, &data->o_res.stateid, data->o_arg.open_flags);
put_inode:
      iput(inode);
out:
      return state;
}

static struct nfs_open_context *nfs4_state_find_open_context(struct nfs4_state *state)
{
      struct nfs_inode *nfsi = NFS_I(state->inode);
      struct nfs_open_context *ctx;

      spin_lock(&state->inode->i_lock);
      list_for_each_entry(ctx, &nfsi->open_files, list) {
            if (ctx->state != state)
                  continue;
            get_nfs_open_context(ctx);
            spin_unlock(&state->inode->i_lock);
            return ctx;
      }
      spin_unlock(&state->inode->i_lock);
      return ERR_PTR(-ENOENT);
}

static int nfs4_open_recover_helper(struct nfs4_opendata *opendata, mode_t openflags, nfs4_stateid *stateid)
{
      int ret;

      opendata->o_arg.open_flags = openflags;
      ret = _nfs4_proc_open(opendata);
      if (ret != 0)
            return ret; 
      memcpy(stateid->data, opendata->o_res.stateid.data,
                  sizeof(stateid->data));
      return 0;
}

static int nfs4_open_recover(struct nfs4_opendata *opendata, struct nfs4_state *state)
{
      nfs4_stateid stateid;
      struct nfs4_state *newstate;
      int mode = 0;
      int delegation = 0;
      int ret;

      /* memory barrier prior to reading state->n_* */
      smp_rmb();
      if (state->n_rdwr != 0) {
            ret = nfs4_open_recover_helper(opendata, FMODE_READ|FMODE_WRITE, &stateid);
            if (ret != 0)
                  return ret;
            mode |= FMODE_READ|FMODE_WRITE;
            if (opendata->o_res.delegation_type != 0)
                  delegation = opendata->o_res.delegation_type;
            smp_rmb();
      }
      if (state->n_wronly != 0) {
            ret = nfs4_open_recover_helper(opendata, FMODE_WRITE, &stateid);
            if (ret != 0)
                  return ret;
            mode |= FMODE_WRITE;
            if (opendata->o_res.delegation_type != 0)
                  delegation = opendata->o_res.delegation_type;
            smp_rmb();
      }
      if (state->n_rdonly != 0) {
            ret = nfs4_open_recover_helper(opendata, FMODE_READ, &stateid);
            if (ret != 0)
                  return ret;
            mode |= FMODE_READ;
      }
      clear_bit(NFS_DELEGATED_STATE, &state->flags);
      if (mode == 0)
            return 0;
      if (opendata->o_res.delegation_type == 0)
            opendata->o_res.delegation_type = delegation;
      opendata->o_arg.open_flags |= mode;
      newstate = nfs4_opendata_to_nfs4_state(opendata);
      if (newstate != NULL) {
            if (opendata->o_res.delegation_type != 0) {
                  struct nfs_inode *nfsi = NFS_I(newstate->inode);
                  int delegation_flags = 0;
                  if (nfsi->delegation)
                        delegation_flags = nfsi->delegation->flags;
                  if (!(delegation_flags & NFS_DELEGATION_NEED_RECLAIM))
                        nfs_inode_set_delegation(newstate->inode,
                                    opendata->owner->so_cred,
                                    &opendata->o_res);
                  else
                        nfs_inode_reclaim_delegation(newstate->inode,
                                    opendata->owner->so_cred,
                                    &opendata->o_res);
            }
            nfs4_close_state(newstate, opendata->o_arg.open_flags);
      }
      if (newstate != state)
            return -ESTALE;
      return 0;
}

/*
 * OPEN_RECLAIM:
 *    reclaim state on the server after a reboot.
 */
static int _nfs4_do_open_reclaim(struct nfs4_state_owner *sp, struct nfs4_state *state, struct dentry *dentry)
{
      struct nfs_delegation *delegation = NFS_I(state->inode)->delegation;
      struct nfs4_opendata *opendata;
      int delegation_type = 0;
      int status;

      if (delegation != NULL) {
            if (!(delegation->flags & NFS_DELEGATION_NEED_RECLAIM)) {
                  memcpy(&state->stateid, &delegation->stateid,
                              sizeof(state->stateid));
                  set_bit(NFS_DELEGATED_STATE, &state->flags);
                  return 0;
            }
            delegation_type = delegation->type;
      }
      opendata = nfs4_opendata_alloc(dentry, sp, 0, NULL);
      if (opendata == NULL)
            return -ENOMEM;
      opendata->o_arg.claim = NFS4_OPEN_CLAIM_PREVIOUS;
      opendata->o_arg.fh = NFS_FH(state->inode);
      nfs_copy_fh(&opendata->o_res.fh, opendata->o_arg.fh);
      opendata->o_arg.u.delegation_type = delegation_type;
      status = nfs4_open_recover(opendata, state);
      nfs4_opendata_free(opendata);
      return status;
}

static int nfs4_do_open_reclaim(struct nfs4_state_owner *sp, struct nfs4_state *state, struct dentry *dentry)
{
      struct nfs_server *server = NFS_SERVER(state->inode);
      struct nfs4_exception exception = { };
      int err;
      do {
            err = _nfs4_do_open_reclaim(sp, state, dentry);
            if (err != -NFS4ERR_DELAY)
                  break;
            nfs4_handle_exception(server, err, &exception);
      } while (exception.retry);
      return err;
}

static int nfs4_open_reclaim(struct nfs4_state_owner *sp, struct nfs4_state *state)
{
      struct nfs_open_context *ctx;
      int ret;

      ctx = nfs4_state_find_open_context(state);
      if (IS_ERR(ctx))
            return PTR_ERR(ctx);
      ret = nfs4_do_open_reclaim(sp, state, ctx->dentry);
      put_nfs_open_context(ctx);
      return ret;
}

static int _nfs4_open_delegation_recall(struct dentry *dentry, struct nfs4_state *state)
{
      struct nfs4_state_owner  *sp  = state->owner;
      struct nfs4_opendata *opendata;
      int ret;

      if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
            return 0;
      opendata = nfs4_opendata_alloc(dentry, sp, 0, NULL);
      if (opendata == NULL)
            return -ENOMEM;
      opendata->o_arg.claim = NFS4_OPEN_CLAIM_DELEGATE_CUR;
      memcpy(opendata->o_arg.u.delegation.data, state->stateid.data,
                  sizeof(opendata->o_arg.u.delegation.data));
      ret = nfs4_open_recover(opendata, state);
      nfs4_opendata_free(opendata);
      return ret;
}

int nfs4_open_delegation_recall(struct dentry *dentry, struct nfs4_state *state)
{
      struct nfs4_exception exception = { };
      struct nfs_server *server = NFS_SERVER(dentry->d_inode);
      int err;
      do {
            err = _nfs4_open_delegation_recall(dentry, state);
            switch (err) {
                  case 0:
                        return err;
                  case -NFS4ERR_STALE_CLIENTID:
                  case -NFS4ERR_STALE_STATEID:
                  case -NFS4ERR_EXPIRED:
                        /* Don't recall a delegation if it was lost */
                        nfs4_schedule_state_recovery(server->nfs4_state);
                        return err;
            }
            err = nfs4_handle_exception(server, err, &exception);
      } while (exception.retry);
      return err;
}

static void nfs4_open_confirm_prepare(struct rpc_task *task, void *calldata)
{
      struct nfs4_opendata *data = calldata;
      struct  rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OPEN_CONFIRM],
            .rpc_argp = &data->c_arg,
            .rpc_resp = &data->c_res,
            .rpc_cred = data->owner->so_cred,
      };
      data->timestamp = jiffies;
      rpc_call_setup(task, &msg, 0);
}

static void nfs4_open_confirm_done(struct rpc_task *task, void *calldata)
{
      struct nfs4_opendata *data = calldata;

      data->rpc_status = task->tk_status;
      if (RPC_ASSASSINATED(task))
            return;
      if (data->rpc_status == 0) {
            memcpy(data->o_res.stateid.data, data->c_res.stateid.data,
                        sizeof(data->o_res.stateid.data));
            renew_lease(data->o_res.server, data->timestamp);
      }
      nfs_increment_open_seqid(data->rpc_status, data->c_arg.seqid);
      nfs_confirm_seqid(&data->owner->so_seqid, data->rpc_status);
}

static void nfs4_open_confirm_release(void *calldata)
{
      struct nfs4_opendata *data = calldata;
      struct nfs4_state *state = NULL;

      /* If this request hasn't been cancelled, do nothing */
      if (data->cancelled == 0)
            goto out_free;
      /* In case of error, no cleanup! */
      if (data->rpc_status != 0)
            goto out_free;
      nfs_confirm_seqid(&data->owner->so_seqid, 0);
      state = nfs4_opendata_to_nfs4_state(data);
      if (state != NULL)
            nfs4_close_state(state, data->o_arg.open_flags);
out_free:
      nfs4_opendata_free(data);
}

static const struct rpc_call_ops nfs4_open_confirm_ops = {
      .rpc_call_prepare = nfs4_open_confirm_prepare,
      .rpc_call_done = nfs4_open_confirm_done,
      .rpc_release = nfs4_open_confirm_release,
};

/*
 * Note: On error, nfs4_proc_open_confirm will free the struct nfs4_opendata
 */
static int _nfs4_proc_open_confirm(struct nfs4_opendata *data)
{
      struct nfs_server *server = NFS_SERVER(data->dir->d_inode);
      struct rpc_task *task;
      int status;

      atomic_inc(&data->count);
      /*
       * If rpc_run_task() ends up calling ->rpc_release(), we
       * want to ensure that it takes the 'error' code path.
       */
      data->rpc_status = -ENOMEM;
      task = rpc_run_task(server->client, RPC_TASK_ASYNC, &nfs4_open_confirm_ops, data);
      if (IS_ERR(task))
            return PTR_ERR(task);
      status = nfs4_wait_for_completion_rpc_task(task);
      if (status != 0) {
            data->cancelled = 1;
            smp_wmb();
      } else
            status = data->rpc_status;
      rpc_release_task(task);
      return status;
}

static void nfs4_open_prepare(struct rpc_task *task, void *calldata)
{
      struct nfs4_opendata *data = calldata;
      struct nfs4_state_owner *sp = data->owner;
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OPEN],
            .rpc_argp = &data->o_arg,
            .rpc_resp = &data->o_res,
            .rpc_cred = sp->so_cred,
      };
      
      if (nfs_wait_on_sequence(data->o_arg.seqid, task) != 0)
            return;
      /* Update sequence id. */
      data->o_arg.id = sp->so_id;
      data->o_arg.clientid = sp->so_client->cl_clientid;
      if (data->o_arg.claim == NFS4_OPEN_CLAIM_PREVIOUS)
            msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OPEN_NOATTR];
      data->timestamp = jiffies;
      rpc_call_setup(task, &msg, 0);
}

static void nfs4_open_done(struct rpc_task *task, void *calldata)
{
      struct nfs4_opendata *data = calldata;

      data->rpc_status = task->tk_status;
      if (RPC_ASSASSINATED(task))
            return;
      if (task->tk_status == 0) {
            switch (data->o_res.f_attr->mode & S_IFMT) {
                  case S_IFREG:
                        break;
                  case S_IFLNK:
                        data->rpc_status = -ELOOP;
                        break;
                  case S_IFDIR:
                        data->rpc_status = -EISDIR;
                        break;
                  default:
                        data->rpc_status = -ENOTDIR;
            }
            renew_lease(data->o_res.server, data->timestamp);
      }
      nfs_increment_open_seqid(data->rpc_status, data->o_arg.seqid);
}

static void nfs4_open_release(void *calldata)
{
      struct nfs4_opendata *data = calldata;
      struct nfs4_state *state = NULL;

      /* If this request hasn't been cancelled, do nothing */
      if (data->cancelled == 0)
            goto out_free;
      /* In case of error, no cleanup! */
      if (data->rpc_status != 0)
            goto out_free;
      /* In case we need an open_confirm, no cleanup! */
      if (data->o_res.rflags & NFS4_OPEN_RESULT_CONFIRM)
            goto out_free;
      nfs_confirm_seqid(&data->owner->so_seqid, 0);
      state = nfs4_opendata_to_nfs4_state(data);
      if (state != NULL)
            nfs4_close_state(state, data->o_arg.open_flags);
out_free:
      nfs4_opendata_free(data);
}

static const struct rpc_call_ops nfs4_open_ops = {
      .rpc_call_prepare = nfs4_open_prepare,
      .rpc_call_done = nfs4_open_done,
      .rpc_release = nfs4_open_release,
};

/*
 * Note: On error, nfs4_proc_open will free the struct nfs4_opendata
 */
static int _nfs4_proc_open(struct nfs4_opendata *data)
{
      struct inode *dir = data->dir->d_inode;
      struct nfs_server *server = NFS_SERVER(dir);
      struct nfs_openargs *o_arg = &data->o_arg;
      struct nfs_openres *o_res = &data->o_res;
      struct rpc_task *task;
      int status;

      atomic_inc(&data->count);
      /*
       * If rpc_run_task() ends up calling ->rpc_release(), we
       * want to ensure that it takes the 'error' code path.
       */
      data->rpc_status = -ENOMEM;
      task = rpc_run_task(server->client, RPC_TASK_ASYNC, &nfs4_open_ops, data);
      if (IS_ERR(task))
            return PTR_ERR(task);
      status = nfs4_wait_for_completion_rpc_task(task);
      if (status != 0) {
            data->cancelled = 1;
            smp_wmb();
      } else
            status = data->rpc_status;
      rpc_release_task(task);
      if (status != 0)
            return status;

      if (o_arg->open_flags & O_CREAT) {
            update_changeattr(dir, &o_res->cinfo);
            nfs_post_op_update_inode(dir, o_res->dir_attr);
      } else
            nfs_refresh_inode(dir, o_res->dir_attr);
      if(o_res->rflags & NFS4_OPEN_RESULT_CONFIRM) {
            status = _nfs4_proc_open_confirm(data);
            if (status != 0)
                  return status;
      }
      nfs_confirm_seqid(&data->owner->so_seqid, 0);
      if (!(o_res->f_attr->valid & NFS_ATTR_FATTR))
            return server->rpc_ops->getattr(server, &o_res->fh, o_res->f_attr);
      return 0;
}

static int _nfs4_do_access(struct inode *inode, struct rpc_cred *cred, int openflags)
{
      struct nfs_access_entry cache;
      int mask = 0;
      int status;

      if (openflags & FMODE_READ)
            mask |= MAY_READ;
      if (openflags & FMODE_WRITE)
            mask |= MAY_WRITE;
      status = nfs_access_get_cached(inode, cred, &cache);
      if (status == 0)
            goto out;

      /* Be clever: ask server to check for all possible rights */
      cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ;
      cache.cred = cred;
      cache.jiffies = jiffies;
      status = _nfs4_proc_access(inode, &cache);
      if (status != 0)
            return status;
      nfs_access_add_cache(inode, &cache);
out:
      if ((cache.mask & mask) == mask)
            return 0;
      return -EACCES;
}

int nfs4_recover_expired_lease(struct nfs_server *server)
{
      struct nfs4_client *clp = server->nfs4_state;

      if (test_and_clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
            nfs4_schedule_state_recovery(clp);
      return nfs4_wait_clnt_recover(server->client, clp);
}

/*
 * OPEN_EXPIRED:
 *    reclaim state on the server after a network partition.
 *    Assumes caller holds the appropriate lock
 */
static int _nfs4_open_expired(struct nfs4_state_owner *sp, struct nfs4_state *state, struct dentry *dentry)
{
      struct inode *inode = state->inode;
      struct nfs_delegation *delegation = NFS_I(inode)->delegation;
      struct nfs4_opendata *opendata;
      int openflags = state->state & (FMODE_READ|FMODE_WRITE);
      int ret;

      if (delegation != NULL && !(delegation->flags & NFS_DELEGATION_NEED_RECLAIM)) {
            ret = _nfs4_do_access(inode, sp->so_cred, openflags);
            if (ret < 0)
                  return ret;
            memcpy(&state->stateid, &delegation->stateid, sizeof(state->stateid));
            set_bit(NFS_DELEGATED_STATE, &state->flags);
            return 0;
      }
      opendata = nfs4_opendata_alloc(dentry, sp, openflags, NULL);
      if (opendata == NULL)
            return -ENOMEM;
      ret = nfs4_open_recover(opendata, state);
      if (ret == -ESTALE) {
            /* Invalidate the state owner so we don't ever use it again */
            nfs4_drop_state_owner(sp);
            d_drop(dentry);
      }
      nfs4_opendata_free(opendata);
      return ret;
}

static inline int nfs4_do_open_expired(struct nfs4_state_owner *sp, struct nfs4_state *state, struct dentry *dentry)
{
      struct nfs_server *server = NFS_SERVER(dentry->d_inode);
      struct nfs4_exception exception = { };
      int err;

      do {
            err = _nfs4_open_expired(sp, state, dentry);
            if (err == -NFS4ERR_DELAY)
                  nfs4_handle_exception(server, err, &exception);
      } while (exception.retry);
      return err;
}

static int nfs4_open_expired(struct nfs4_state_owner *sp, struct nfs4_state *state)
{
      struct nfs_open_context *ctx;
      int ret;

      ctx = nfs4_state_find_open_context(state);
      if (IS_ERR(ctx))
            return PTR_ERR(ctx);
      ret = nfs4_do_open_expired(sp, state, ctx->dentry);
      put_nfs_open_context(ctx);
      return ret;
}

/*
 * Returns a referenced nfs4_state if there is an open delegation on the file
 */
static int _nfs4_open_delegated(struct inode *inode, int flags, struct rpc_cred *cred, struct nfs4_state **res)
{
      struct nfs_delegation *delegation;
      struct nfs_server *server = NFS_SERVER(inode);
      struct nfs4_client *clp = server->nfs4_state;
      struct nfs_inode *nfsi = NFS_I(inode);
      struct nfs4_state_owner *sp = NULL;
      struct nfs4_state *state = NULL;
      int open_flags = flags & (FMODE_READ|FMODE_WRITE);
      int err;

      err = -ENOMEM;
      if (!(sp = nfs4_get_state_owner(server, cred))) {
            dprintk("%s: nfs4_get_state_owner failed!\n", __FUNCTION__);
            return err;
      }
      err = nfs4_recover_expired_lease(server);
      if (err != 0)
            goto out_put_state_owner;
      /* Protect against reboot recovery - NOTE ORDER! */
      down_read(&clp->cl_sem);
      /* Protect against delegation recall */
      down_read(&nfsi->rwsem);
      delegation = NFS_I(inode)->delegation;
      err = -ENOENT;
      if (delegation == NULL || (delegation->type & open_flags) != open_flags)
            goto out_err;
      err = -ENOMEM;
      state = nfs4_get_open_state(inode, sp);
      if (state == NULL)
            goto out_err;

      err = -ENOENT;
      if ((state->state & open_flags) == open_flags) {
            spin_lock(&inode->i_lock);
            update_open_stateflags(state, open_flags);
            spin_unlock(&inode->i_lock);
            goto out_ok;
      } else if (state->state != 0)
            goto out_put_open_state;

      lock_kernel();
      err = _nfs4_do_access(inode, cred, open_flags);
      unlock_kernel();
      if (err != 0)
            goto out_put_open_state;
      set_bit(NFS_DELEGATED_STATE, &state->flags);
      update_open_stateid(state, &delegation->stateid, open_flags);
out_ok:
      nfs4_put_state_owner(sp);
      up_read(&nfsi->rwsem);
      up_read(&clp->cl_sem);
      *res = state;
      return 0;
out_put_open_state:
      nfs4_put_open_state(state);
out_err:
      up_read(&nfsi->rwsem);
      up_read(&clp->cl_sem);
      if (err != -EACCES)
            nfs_inode_return_delegation(inode);
out_put_state_owner:
      nfs4_put_state_owner(sp);
      return err;
}

static struct nfs4_state *nfs4_open_delegated(struct inode *inode, int flags, struct rpc_cred *cred)
{
      struct nfs4_exception exception = { };
      struct nfs4_state *res = ERR_PTR(-EIO);
      int err;

      do {
            err = _nfs4_open_delegated(inode, flags, cred, &res);
            if (err == 0)
                  break;
            res = ERR_PTR(nfs4_handle_exception(NFS_SERVER(inode),
                              err, &exception));
      } while (exception.retry);
      return res;
}

/*
 * Returns a referenced nfs4_state
 */
static int _nfs4_do_open(struct inode *dir, struct dentry *dentry, int flags, struct iattr *sattr, struct rpc_cred *cred, struct nfs4_state **res)
{
      struct nfs4_state_owner  *sp;
      struct nfs4_state     *state = NULL;
      struct nfs_server       *server = NFS_SERVER(dir);
      struct nfs4_client *clp = server->nfs4_state;
      struct nfs4_opendata *opendata;
      int                     status;

      /* Protect against reboot recovery conflicts */
      status = -ENOMEM;
      if (!(sp = nfs4_get_state_owner(server, cred))) {
            dprintk("nfs4_do_open: nfs4_get_state_owner failed!\n");
            goto out_err;
      }
      status = nfs4_recover_expired_lease(server);
      if (status != 0)
            goto err_put_state_owner;
      down_read(&clp->cl_sem);
      status = -ENOMEM;
      opendata = nfs4_opendata_alloc(dentry, sp, flags, sattr);
      if (opendata == NULL)
            goto err_release_rwsem;

      status = _nfs4_proc_open(opendata);
      if (status != 0)
            goto err_opendata_free;

      status = -ENOMEM;
      state = nfs4_opendata_to_nfs4_state(opendata);
      if (state == NULL)
            goto err_opendata_free;
      if (opendata->o_res.delegation_type != 0)
            nfs_inode_set_delegation(state->inode, cred, &opendata->o_res);
      nfs4_opendata_free(opendata);
      nfs4_put_state_owner(sp);
      up_read(&clp->cl_sem);
      *res = state;
      return 0;
err_opendata_free:
      nfs4_opendata_free(opendata);
err_release_rwsem:
      up_read(&clp->cl_sem);
err_put_state_owner:
      nfs4_put_state_owner(sp);
out_err:
      *res = NULL;
      return status;
}


static struct nfs4_state *nfs4_do_open(struct inode *dir, struct dentry *dentry, int flags, struct iattr *sattr, struct rpc_cred *cred)
{
      struct nfs4_exception exception = { };
      struct nfs4_state *res;
      int status;

      do {
            status = _nfs4_do_open(dir, dentry, flags, sattr, cred, &res);
            if (status == 0)
                  break;
            /* NOTE: BAD_SEQID means the server and client disagree about the
             * book-keeping w.r.t. state-changing operations
             * (OPEN/CLOSE/LOCK/LOCKU...)
             * It is actually a sign of a bug on the client or on the server.
             *
             * If we receive a BAD_SEQID error in the particular case of
             * doing an OPEN, we assume that nfs_increment_open_seqid() will
             * have unhashed the old state_owner for us, and that we can
             * therefore safely retry using a new one. We should still warn
             * the user though...
             */
            if (status == -NFS4ERR_BAD_SEQID) {
                  printk(KERN_WARNING "NFS: v4 server returned a bad sequence-id error!\n");
                  exception.retry = 1;
                  continue;
            }
            /*
             * BAD_STATEID on OPEN means that the server cancelled our
             * state before it received the OPEN_CONFIRM.
             * Recover by retrying the request as per the discussion
             * on Page 181 of RFC3530.
             */
            if (status == -NFS4ERR_BAD_STATEID) {
                  exception.retry = 1;
                  continue;
            }
            res = ERR_PTR(nfs4_handle_exception(NFS_SERVER(dir),
                              status, &exception));
      } while (exception.retry);
      return res;
}

static int _nfs4_do_setattr(struct inode *inode, struct nfs_fattr *fattr,
                struct iattr *sattr, struct nfs4_state *state)
{
      struct nfs_server *server = NFS_SERVER(inode);
        struct nfs_setattrargs  arg = {
                .fh             = NFS_FH(inode),
                .iap            = sattr,
            .server           = server,
            .bitmask = server->attr_bitmask,
        };
        struct nfs_setattrres  res = {
            .fattr            = fattr,
            .server           = server,
        };
        struct rpc_message msg = {
                .rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_SETATTR],
                .rpc_argp       = &arg,
                .rpc_resp       = &res,
        };
      unsigned long timestamp = jiffies;
      int status;

      nfs_fattr_init(fattr);

      if (nfs4_copy_delegation_stateid(&arg.stateid, inode)) {
            /* Use that stateid */
      } else if (state != NULL) {
            msg.rpc_cred = state->owner->so_cred;
            nfs4_copy_stateid(&arg.stateid, state, current->files);
      } else
            memcpy(&arg.stateid, &zero_stateid, sizeof(arg.stateid));

      status = rpc_call_sync(server->client, &msg, 0);
      if (status == 0 && state != NULL)
            renew_lease(server, timestamp);
      return status;
}

static int nfs4_do_setattr(struct inode *inode, struct nfs_fattr *fattr,
                struct iattr *sattr, struct nfs4_state *state)
{
      struct nfs_server *server = NFS_SERVER(inode);
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(server,
                        _nfs4_do_setattr(inode, fattr, sattr, state),
                        &exception);
      } while (exception.retry);
      return err;
}

struct nfs4_closedata {
      struct inode *inode;
      struct nfs4_state *state;
      struct nfs_closeargs arg;
      struct nfs_closeres res;
      struct nfs_fattr fattr;
      unsigned long timestamp;
};

static void nfs4_free_closedata(void *data)
{
      struct nfs4_closedata *calldata = data;
      struct nfs4_state_owner *sp = calldata->state->owner;

      nfs4_put_open_state(calldata->state);
      nfs_free_seqid(calldata->arg.seqid);
      nfs4_put_state_owner(sp);
      kfree(calldata);
}

static void nfs4_close_done(struct rpc_task *task, void *data)
{
      struct nfs4_closedata *calldata = data;
      struct nfs4_state *state = calldata->state;
      struct nfs_server *server = NFS_SERVER(calldata->inode);

      if (RPC_ASSASSINATED(task))
            return;
        /* hmm. we are done with the inode, and in the process of freeing
       * the state_owner. we keep this around to process errors
       */
      nfs_increment_open_seqid(task->tk_status, calldata->arg.seqid);
      switch (task->tk_status) {
            case 0:
                  memcpy(&state->stateid, &calldata->res.stateid,
                              sizeof(state->stateid));
                  renew_lease(server, calldata->timestamp);
                  break;
            case -NFS4ERR_STALE_STATEID:
            case -NFS4ERR_EXPIRED:
                  nfs4_schedule_state_recovery(server->nfs4_state);
                  break;
            default:
                  if (nfs4_async_handle_error(task, server) == -EAGAIN) {
                        rpc_restart_call(task);
                        return;
                  }
      }
      nfs_refresh_inode(calldata->inode, calldata->res.fattr);
}

static void nfs4_close_prepare(struct rpc_task *task, void *data)
{
      struct nfs4_closedata *calldata = data;
      struct nfs4_state *state = calldata->state;
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_CLOSE],
            .rpc_argp = &calldata->arg,
            .rpc_resp = &calldata->res,
            .rpc_cred = state->owner->so_cred,
      };
      int mode = 0, old_mode;

      if (nfs_wait_on_sequence(calldata->arg.seqid, task) != 0)
            return;
      /* Recalculate the new open mode in case someone reopened the file
       * while we were waiting in line to be scheduled.
       */
      spin_lock(&state->owner->so_lock);
      spin_lock(&calldata->inode->i_lock);
      mode = old_mode = state->state;
      if (state->n_rdwr == 0) {
            if (state->n_rdonly == 0)
                  mode &= ~FMODE_READ;
            if (state->n_wronly == 0)
                  mode &= ~FMODE_WRITE;
      }
      nfs4_state_set_mode_locked(state, mode);
      spin_unlock(&calldata->inode->i_lock);
      spin_unlock(&state->owner->so_lock);
      if (mode == old_mode || test_bit(NFS_DELEGATED_STATE, &state->flags)) {
            /* Note: exit _without_ calling nfs4_close_done */
            task->tk_action = NULL;
            return;
      }
      nfs_fattr_init(calldata->res.fattr);
      if (mode != 0)
            msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OPEN_DOWNGRADE];
      calldata->arg.open_flags = mode;
      calldata->timestamp = jiffies;
      rpc_call_setup(task, &msg, 0);
}

static const struct rpc_call_ops nfs4_close_ops = {
      .rpc_call_prepare = nfs4_close_prepare,
      .rpc_call_done = nfs4_close_done,
      .rpc_release = nfs4_free_closedata,
};

/* 
 * It is possible for data to be read/written from a mem-mapped file 
 * after the sys_close call (which hits the vfs layer as a flush).
 * This means that we can't safely call nfsv4 close on a file until 
 * the inode is cleared. This in turn means that we are not good
 * NFSv4 citizens - we do not indicate to the server to update the file's 
 * share state even when we are done with one of the three share 
 * stateid's in the inode.
 *
 * NOTE: Caller must be holding the sp->so_owner semaphore!
 */
int nfs4_do_close(struct inode *inode, struct nfs4_state *state) 
{
      struct nfs_server *server = NFS_SERVER(inode);
      struct nfs4_closedata *calldata;
      int status = -ENOMEM;

      calldata = kmalloc(sizeof(*calldata), GFP_KERNEL);
      if (calldata == NULL)
            goto out;
      calldata->inode = inode;
      calldata->state = state;
      calldata->arg.fh = NFS_FH(inode);
      calldata->arg.stateid = &state->stateid;
      /* Serialization for the sequence id */
      calldata->arg.seqid = nfs_alloc_seqid(&state->owner->so_seqid);
      if (calldata->arg.seqid == NULL)
            goto out_free_calldata;
      calldata->arg.bitmask = server->attr_bitmask;
      calldata->res.fattr = &calldata->fattr;
      calldata->res.server = server;

      status = nfs4_call_async(server->client, &nfs4_close_ops, calldata);
      if (status == 0)
            goto out;

      nfs_free_seqid(calldata->arg.seqid);
out_free_calldata:
      kfree(calldata);
out:
      return status;
}

static int nfs4_intent_set_file(struct nameidata *nd, struct dentry *dentry, struct nfs4_state *state)
{
      struct file *filp;

      filp = lookup_instantiate_filp(nd, dentry, NULL);
      if (!IS_ERR(filp)) {
            struct nfs_open_context *ctx;
            ctx = (struct nfs_open_context *)filp->private_data;
            ctx->state = state;
            return 0;
      }
      nfs4_close_state(state, nd->intent.open.flags);
      return PTR_ERR(filp);
}

struct dentry *
nfs4_atomic_open(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
      struct iattr attr;
      struct rpc_cred *cred;
      struct nfs4_state *state;
      struct dentry *res;

      if (nd->flags & LOOKUP_CREATE) {
            attr.ia_mode = nd->intent.open.create_mode;
            attr.ia_valid = ATTR_MODE;
            if (!IS_POSIXACL(dir))
                  attr.ia_mode &= ~current->fs->umask;
      } else {
            attr.ia_valid = 0;
            BUG_ON(nd->intent.open.flags & O_CREAT);
      }

      cred = rpcauth_lookupcred(NFS_SERVER(dir)->client->cl_auth, 0);
      if (IS_ERR(cred))
            return (struct dentry *)cred;
      state = nfs4_do_open(dir, dentry, nd->intent.open.flags, &attr, cred);
      put_rpccred(cred);
      if (IS_ERR(state)) {
            if (PTR_ERR(state) == -ENOENT)
                  d_add(dentry, NULL);
            return (struct dentry *)state;
      }
      res = d_add_unique(dentry, igrab(state->inode));
      if (res != NULL)
            dentry = res;
      nfs4_intent_set_file(nd, dentry, state);
      return res;
}

int
nfs4_open_revalidate(struct inode *dir, struct dentry *dentry, int openflags, struct nameidata *nd)
{
      struct rpc_cred *cred;
      struct nfs4_state *state;

      cred = rpcauth_lookupcred(NFS_SERVER(dir)->client->cl_auth, 0);
      if (IS_ERR(cred))
            return PTR_ERR(cred);
      state = nfs4_open_delegated(dentry->d_inode, openflags, cred);
      if (IS_ERR(state))
            state = nfs4_do_open(dir, dentry, openflags, NULL, cred);
      put_rpccred(cred);
      if (IS_ERR(state)) {
            switch (PTR_ERR(state)) {
                  case -EPERM:
                  case -EACCES:
                  case -EDQUOT:
                  case -ENOSPC:
                  case -EROFS:
                        lookup_instantiate_filp(nd, (struct dentry *)state, NULL);
                        return 1;
                  case -ENOENT:
                        if (dentry->d_inode == NULL)
                              return 1;
            }
            goto out_drop;
      }
      if (state->inode == dentry->d_inode) {
            nfs4_intent_set_file(nd, dentry, state);
            return 1;
      }
      nfs4_close_state(state, openflags);
out_drop:
      d_drop(dentry);
      return 0;
}


static int _nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle)
{
      struct nfs4_server_caps_res res = {};
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SERVER_CAPS],
            .rpc_argp = fhandle,
            .rpc_resp = &res,
      };
      int status;

      status = rpc_call_sync(server->client, &msg, 0);
      if (status == 0) {
            memcpy(server->attr_bitmask, res.attr_bitmask, sizeof(server->attr_bitmask));
            if (res.attr_bitmask[0] & FATTR4_WORD0_ACL)
                  server->caps |= NFS_CAP_ACLS;
            if (res.has_links != 0)
                  server->caps |= NFS_CAP_HARDLINKS;
            if (res.has_symlinks != 0)
                  server->caps |= NFS_CAP_SYMLINKS;
            server->acl_bitmask = res.acl_bitmask;
      }
      return status;
}

int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(server,
                        _nfs4_server_capabilities(server, fhandle),
                        &exception);
      } while (exception.retry);
      return err;
}

static int _nfs4_lookup_root(struct nfs_server *server, struct nfs_fh *fhandle,
            struct nfs_fsinfo *info)
{
      struct nfs4_lookup_root_arg args = {
            .bitmask = nfs4_fattr_bitmap,
      };
      struct nfs4_lookup_res res = {
            .server = server,
            .fattr = info->fattr,
            .fh = fhandle,
      };
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LOOKUP_ROOT],
            .rpc_argp = &args,
            .rpc_resp = &res,
      };
      nfs_fattr_init(info->fattr);
      return rpc_call_sync(server->client, &msg, 0);
}

static int nfs4_lookup_root(struct nfs_server *server, struct nfs_fh *fhandle,
            struct nfs_fsinfo *info)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(server,
                        _nfs4_lookup_root(server, fhandle, info),
                        &exception);
      } while (exception.retry);
      return err;
}

static int nfs4_proc_get_root(struct nfs_server *server, struct nfs_fh *fhandle,
            struct nfs_fsinfo *info)
{
      struct nfs_fattr *      fattr = info->fattr;
      unsigned char *         p;
      struct qstr       q;
      struct nfs4_lookup_arg args = {
            .dir_fh = fhandle,
            .name = &q,
            .bitmask = nfs4_fattr_bitmap,
      };
      struct nfs4_lookup_res res = {
            .server = server,
            .fattr = fattr,
            .fh = fhandle,
      };
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LOOKUP],
            .rpc_argp = &args,
            .rpc_resp = &res,
      };
      int status;

      /*
       * Now we do a separate LOOKUP for each component of the mount path.
       * The LOOKUPs are done separately so that we can conveniently
       * catch an ERR_WRONGSEC if it occurs along the way...
       */
      status = nfs4_lookup_root(server, fhandle, info);
      if (status)
            goto out;

      p = server->mnt_path;
      for (;;) {
            struct nfs4_exception exception = { };

            while (*p == '/')
                  p++;
            if (!*p)
                  break;
            q.name = p;
            while (*p && (*p != '/'))
                  p++;
            q.len = p - q.name;

            do {
                  nfs_fattr_init(fattr);
                  status = nfs4_handle_exception(server,
                              rpc_call_sync(server->client, &msg, 0),
                              &exception);
            } while (exception.retry);
            if (status == 0)
                  continue;
            if (status == -ENOENT) {
                  printk(KERN_NOTICE "NFS: mount path %s does not exist!\n", server->mnt_path);
                  printk(KERN_NOTICE "NFS: suggestion: try mounting '/' instead.\n");
            }
            break;
      }
      if (status == 0)
            status = nfs4_server_capabilities(server, fhandle);
      if (status == 0)
            status = nfs4_do_fsinfo(server, fhandle, info);
out:
      return nfs4_map_errors(status);
}

/*
 * Get locations and (maybe) other attributes of a referral.
 * Note that we'll actually follow the referral later when
 * we detect fsid mismatch in inode revalidation
 */
static int nfs4_get_referral(struct inode *dir, struct qstr *name, struct nfs_fattr *fattr, struct nfs_fh *fhandle)
{
      int status = -ENOMEM;
      struct page *page = NULL;
      struct nfs4_fs_locations *locations = NULL;
      struct dentry dentry = {};

      page = alloc_page(GFP_KERNEL);
      if (page == NULL)
            goto out;
      locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
      if (locations == NULL)
            goto out;

      dentry.d_name.name = name->name;
      dentry.d_name.len = name->len;
      status = nfs4_proc_fs_locations(dir, &dentry, locations, page);
      if (status != 0)
            goto out;
      /* Make sure server returned a different fsid for the referral */
      if (nfs_fsid_equal(&NFS_SERVER(dir)->fsid, &locations->fattr.fsid)) {
            dprintk("%s: server did not return a different fsid for a referral at %s\n", __FUNCTION__, name->name);
            status = -EIO;
            goto out;
      }

      memcpy(fattr, &locations->fattr, sizeof(struct nfs_fattr));
      fattr->valid |= NFS_ATTR_FATTR_V4_REFERRAL;
      if (!fattr->mode)
            fattr->mode = S_IFDIR;
      memset(fhandle, 0, sizeof(struct nfs_fh));
out:
      if (page)
            __free_page(page);
      if (locations)
            kfree(locations);
      return status;
}

static int _nfs4_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle, struct nfs_fattr *fattr)
{
      struct nfs4_getattr_arg args = {
            .fh = fhandle,
            .bitmask = server->attr_bitmask,
      };
      struct nfs4_getattr_res res = {
            .fattr = fattr,
            .server = server,
      };
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_GETATTR],
            .rpc_argp = &args,
            .rpc_resp = &res,
      };
      
      nfs_fattr_init(fattr);
      return rpc_call_sync(server->client, &msg, 0);
}

static int nfs4_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle, struct nfs_fattr *fattr)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(server,
                        _nfs4_proc_getattr(server, fhandle, fattr),
                        &exception);
      } while (exception.retry);
      return err;
}

/* 
 * The file is not closed if it is opened due to the a request to change
 * the size of the file. The open call will not be needed once the
 * VFS layer lookup-intents are implemented.
 *
 * Close is called when the inode is destroyed.
 * If we haven't opened the file for O_WRONLY, we
 * need to in the size_change case to obtain a stateid.
 *
 * Got race?
 * Because OPEN is always done by name in nfsv4, it is
 * possible that we opened a different file by the same
 * name.  We can recognize this race condition, but we
 * can't do anything about it besides returning an error.
 *
 * This will be fixed with VFS changes (lookup-intent).
 */
static int
nfs4_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
              struct iattr *sattr)
{
      struct rpc_cred *cred;
      struct inode *inode = dentry->d_inode;
      struct nfs_open_context *ctx;
      struct nfs4_state *state = NULL;
      int status;

      nfs_fattr_init(fattr);
      
      cred = rpcauth_lookupcred(NFS_SERVER(inode)->client->cl_auth, 0);
      if (IS_ERR(cred))
            return PTR_ERR(cred);

      /* Search for an existing open(O_WRITE) file */
      ctx = nfs_find_open_context(inode, cred, FMODE_WRITE);
      if (ctx != NULL)
            state = ctx->state;

      status = nfs4_do_setattr(inode, fattr, sattr, state);
      if (status == 0)
            nfs_setattr_update_inode(inode, sattr);
      if (ctx != NULL)
            put_nfs_open_context(ctx);
      put_rpccred(cred);
      return status;
}

static int _nfs4_proc_lookup(struct inode *dir, struct qstr *name,
            struct nfs_fh *fhandle, struct nfs_fattr *fattr)
{
      int                status;
      struct nfs_server *server = NFS_SERVER(dir);
      struct nfs4_lookup_arg args = {
            .bitmask = server->attr_bitmask,
            .dir_fh = NFS_FH(dir),
            .name = name,
      };
      struct nfs4_lookup_res res = {
            .server = server,
            .fattr = fattr,
            .fh = fhandle,
      };
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LOOKUP],
            .rpc_argp = &args,
            .rpc_resp = &res,
      };
      
      nfs_fattr_init(fattr);
      
      dprintk("NFS call  lookup %s\n", name->name);
      status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
      if (status == -NFS4ERR_MOVED)
            status = nfs4_get_referral(dir, name, fattr, fhandle);
      dprintk("NFS reply lookup: %d\n", status);
      return status;
}

static int nfs4_proc_lookup(struct inode *dir, struct qstr *name, struct nfs_fh *fhandle, struct nfs_fattr *fattr)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(NFS_SERVER(dir),
                        _nfs4_proc_lookup(dir, name, fhandle, fattr),
                        &exception);
      } while (exception.retry);
      return err;
}

static int _nfs4_proc_access(struct inode *inode, struct nfs_access_entry *entry)
{
      struct nfs4_accessargs args = {
            .fh = NFS_FH(inode),
      };
      struct nfs4_accessres res = { 0 };
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_ACCESS],
            .rpc_argp = &args,
            .rpc_resp = &res,
            .rpc_cred = entry->cred,
      };
      int mode = entry->mask;
      int status;

      /*
       * Determine which access bits we want to ask for...
       */
      if (mode & MAY_READ)
            args.access |= NFS4_ACCESS_READ;
      if (S_ISDIR(inode->i_mode)) {
            if (mode & MAY_WRITE)
                  args.access |= NFS4_ACCESS_MODIFY | NFS4_ACCESS_EXTEND | NFS4_ACCESS_DELETE;
            if (mode & MAY_EXEC)
                  args.access |= NFS4_ACCESS_LOOKUP;
      } else {
            if (mode & MAY_WRITE)
                  args.access |= NFS4_ACCESS_MODIFY | NFS4_ACCESS_EXTEND;
            if (mode & MAY_EXEC)
                  args.access |= NFS4_ACCESS_EXECUTE;
      }
      status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
      if (!status) {
            entry->mask = 0;
            if (res.access & NFS4_ACCESS_READ)
                  entry->mask |= MAY_READ;
            if (res.access & (NFS4_ACCESS_MODIFY | NFS4_ACCESS_EXTEND | NFS4_ACCESS_DELETE))
                  entry->mask |= MAY_WRITE;
            if (res.access & (NFS4_ACCESS_LOOKUP|NFS4_ACCESS_EXECUTE))
                  entry->mask |= MAY_EXEC;
      }
      return status;
}

static int nfs4_proc_access(struct inode *inode, struct nfs_access_entry *entry)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(NFS_SERVER(inode),
                        _nfs4_proc_access(inode, entry),
                        &exception);
      } while (exception.retry);
      return err;
}

/*
 * TODO: For the time being, we don't try to get any attributes
 * along with any of the zero-copy operations READ, READDIR,
 * READLINK, WRITE.
 *
 * In the case of the first three, we want to put the GETATTR
 * after the read-type operation -- this is because it is hard
 * to predict the length of a GETATTR response in v4, and thus
 * align the READ data correctly.  This means that the GETATTR
 * may end up partially falling into the page cache, and we should
 * shift it into the 'tail' of the xdr_buf before processing.
 * To do this efficiently, we need to know the total length
 * of data received, which doesn't seem to be available outside
 * of the RPC layer.
 *
 * In the case of WRITE, we also want to put the GETATTR after
 * the operation -- in this case because we want to make sure
 * we get the post-operation mtime and size.  This means that
 * we can't use xdr_encode_pages() as written: we need a variant
 * of it which would leave room in the 'tail' iovec.
 *
 * Both of these changes to the XDR layer would in fact be quite
 * minor, but I decided to leave them for a subsequent patch.
 */
static int _nfs4_proc_readlink(struct inode *inode, struct page *page,
            unsigned int pgbase, unsigned int pglen)
{
      struct nfs4_readlink args = {
            .fh       = NFS_FH(inode),
            .pgbase       = pgbase,
            .pglen    = pglen,
            .pages    = &page,
      };
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READLINK],
            .rpc_argp = &args,
            .rpc_resp = NULL,
      };

      return rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
}

static int nfs4_proc_readlink(struct inode *inode, struct page *page,
            unsigned int pgbase, unsigned int pglen)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(NFS_SERVER(inode),
                        _nfs4_proc_readlink(inode, page, pgbase, pglen),
                        &exception);
      } while (exception.retry);
      return err;
}

static int _nfs4_proc_read(struct nfs_read_data *rdata)
{
      int flags = rdata->flags;
      struct inode *inode = rdata->inode;
      struct nfs_fattr *fattr = rdata->res.fattr;
      struct nfs_server *server = NFS_SERVER(inode);
      struct rpc_message msg = {
            .rpc_proc   = &nfs4_procedures[NFSPROC4_CLNT_READ],
            .rpc_argp   = &rdata->args,
            .rpc_resp   = &rdata->res,
            .rpc_cred   = rdata->cred,
      };
      unsigned long timestamp = jiffies;
      int status;

      dprintk("NFS call  read %d @ %Ld\n", rdata->args.count,
                  (long long) rdata->args.offset);

      nfs_fattr_init(fattr);
      status = rpc_call_sync(server->client, &msg, flags);
      if (!status)
            renew_lease(server, timestamp);
      dprintk("NFS reply read: %d\n", status);
      return status;
}

static int nfs4_proc_read(struct nfs_read_data *rdata)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(NFS_SERVER(rdata->inode),
                        _nfs4_proc_read(rdata),
                        &exception);
      } while (exception.retry);
      return err;
}

static int _nfs4_proc_write(struct nfs_write_data *wdata)
{
      int rpcflags = wdata->flags;
      struct inode *inode = wdata->inode;
      struct nfs_fattr *fattr = wdata->res.fattr;
      struct nfs_server *server = NFS_SERVER(inode);
      struct rpc_message msg = {
            .rpc_proc   = &nfs4_procedures[NFSPROC4_CLNT_WRITE],
            .rpc_argp   = &wdata->args,
            .rpc_resp   = &wdata->res,
            .rpc_cred   = wdata->cred,
      };
      int status;

      dprintk("NFS call  write %d @ %Ld\n", wdata->args.count,
                  (long long) wdata->args.offset);

      wdata->args.bitmask = server->attr_bitmask;
      wdata->res.server = server;
      wdata->timestamp = jiffies;
      nfs_fattr_init(fattr);
      status = rpc_call_sync(server->client, &msg, rpcflags);
      dprintk("NFS reply write: %d\n", status);
      if (status < 0)
            return status;
      renew_lease(server, wdata->timestamp);
      nfs_post_op_update_inode(inode, fattr);
      return wdata->res.count;
}

static int nfs4_proc_write(struct nfs_write_data *wdata)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(NFS_SERVER(wdata->inode),
                        _nfs4_proc_write(wdata),
                        &exception);
      } while (exception.retry);
      return err;
}

static int _nfs4_proc_commit(struct nfs_write_data *cdata)
{
      struct inode *inode = cdata->inode;
      struct nfs_fattr *fattr = cdata->res.fattr;
      struct nfs_server *server = NFS_SERVER(inode);
      struct rpc_message msg = {
            .rpc_proc   = &nfs4_procedures[NFSPROC4_CLNT_COMMIT],
            .rpc_argp   = &cdata->args,
            .rpc_resp   = &cdata->res,
            .rpc_cred   = cdata->cred,
      };
      int status;

      dprintk("NFS call  commit %d @ %Ld\n", cdata->args.count,
                  (long long) cdata->args.offset);

      cdata->args.bitmask = server->attr_bitmask;
      cdata->res.server = server;
      cdata->timestamp = jiffies;
      nfs_fattr_init(fattr);
      status = rpc_call_sync(server->client, &msg, 0);
      if (status >= 0)
            renew_lease(server, cdata->timestamp);
      dprintk("NFS reply commit: %d\n", status);
      if (status >= 0)
            nfs_post_op_update_inode(inode, fattr);
      return status;
}

static int nfs4_proc_commit(struct nfs_write_data *cdata)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(NFS_SERVER(cdata->inode),
                        _nfs4_proc_commit(cdata),
                        &exception);
      } while (exception.retry);
      return err;
}

/*
 * Got race?
 * We will need to arrange for the VFS layer to provide an atomic open.
 * Until then, this create/open method is prone to inefficiency and race
 * conditions due to the lookup, create, and open VFS calls from sys_open()
 * placed on the wire.
 *
 * Given the above sorry state of affairs, I'm simply sending an OPEN.
 * The file will be opened again in the subsequent VFS open call
 * (nfs4_proc_file_open).
 *
 * The open for read will just hang around to be used by any process that
 * opens the file O_RDONLY. This will all be resolved with the VFS changes.
 */

static int
nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
                 int flags, struct nameidata *nd)
{
      struct nfs4_state *state;
      struct rpc_cred *cred;
      int status = 0;

      cred = rpcauth_lookupcred(NFS_SERVER(dir)->client->cl_auth, 0);
      if (IS_ERR(cred)) {
            status = PTR_ERR(cred);
            goto out;
      }
      state = nfs4_do_open(dir, dentry, flags, sattr, cred);
      put_rpccred(cred);
      if (IS_ERR(state)) {
            status = PTR_ERR(state);
            goto out;
      }
      d_instantiate(dentry, igrab(state->inode));
      if (flags & O_EXCL) {
            struct nfs_fattr fattr;
            status = nfs4_do_setattr(state->inode, &fattr, sattr, state);
            if (status == 0)
                  nfs_setattr_update_inode(state->inode, sattr);
      }
      if (status == 0 && nd != NULL && (nd->flags & LOOKUP_OPEN))
            status = nfs4_intent_set_file(nd, dentry, state);
      else
            nfs4_close_state(state, flags);
out:
      return status;
}

static int _nfs4_proc_remove(struct inode *dir, struct qstr *name)
{
      struct nfs_server *server = NFS_SERVER(dir);
      struct nfs4_remove_arg args = {
            .fh = NFS_FH(dir),
            .name = name,
            .bitmask = server->attr_bitmask,
      };
      struct nfs_fattr dir_attr;
      struct nfs4_remove_res  res = {
            .server = server,
            .dir_attr = &dir_attr,
      };
      struct rpc_message msg = {
            .rpc_proc   = &nfs4_procedures[NFSPROC4_CLNT_REMOVE],
            .rpc_argp   = &args,
            .rpc_resp   = &res,
      };
      int               status;

      nfs_fattr_init(res.dir_attr);
      status = rpc_call_sync(server->client, &msg, 0);
      if (status == 0) {
            update_changeattr(dir, &res.cinfo);
            nfs_post_op_update_inode(dir, res.dir_attr);
      }
      return status;
}

static int nfs4_proc_remove(struct inode *dir, struct qstr *name)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(NFS_SERVER(dir),
                        _nfs4_proc_remove(dir, name),
                        &exception);
      } while (exception.retry);
      return err;
}

struct unlink_desc {
      struct nfs4_remove_arg  args;
      struct nfs4_remove_res  res;
      struct nfs_fattr dir_attr;
};

static int nfs4_proc_unlink_setup(struct rpc_message *msg, struct dentry *dir,
            struct qstr *name)
{
      struct nfs_server *server = NFS_SERVER(dir->d_inode);
      struct unlink_desc *up;

      up = (struct unlink_desc *) kmalloc(sizeof(*up), GFP_KERNEL);
      if (!up)
            return -ENOMEM;
      
      up->args.fh = NFS_FH(dir->d_inode);
      up->args.name = name;
      up->args.bitmask = server->attr_bitmask;
      up->res.server = server;
      up->res.dir_attr = &up->dir_attr;
      
      msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_REMOVE];
      msg->rpc_argp = &up->args;
      msg->rpc_resp = &up->res;
      return 0;
}

static int nfs4_proc_unlink_done(struct dentry *dir, struct rpc_task *task)
{
      struct rpc_message *msg = &task->tk_msg;
      struct unlink_desc *up;
      
      if (msg->rpc_resp != NULL) {
            up = container_of(msg->rpc_resp, struct unlink_desc, res);
            update_changeattr(dir->d_inode, &up->res.cinfo);
            nfs_post_op_update_inode(dir->d_inode, up->res.dir_attr);
            kfree(up);
            msg->rpc_resp = NULL;
            msg->rpc_argp = NULL;
      }
      return 0;
}

static int _nfs4_proc_rename(struct inode *old_dir, struct qstr *old_name,
            struct inode *new_dir, struct qstr *new_name)
{
      struct nfs_server *server = NFS_SERVER(old_dir);
      struct nfs4_rename_arg arg = {
            .old_dir = NFS_FH(old_dir),
            .new_dir = NFS_FH(new_dir),
            .old_name = old_name,
            .new_name = new_name,
            .bitmask = server->attr_bitmask,
      };
      struct nfs_fattr old_fattr, new_fattr;
      struct nfs4_rename_res res = {
            .server = server,
            .old_fattr = &old_fattr,
            .new_fattr = &new_fattr,
      };
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_RENAME],
            .rpc_argp = &arg,
            .rpc_resp = &res,
      };
      int               status;
      
      nfs_fattr_init(res.old_fattr);
      nfs_fattr_init(res.new_fattr);
      status = rpc_call_sync(server->client, &msg, 0);

      if (!status) {
            update_changeattr(old_dir, &res.old_cinfo);
            nfs_post_op_update_inode(old_dir, res.old_fattr);
            update_changeattr(new_dir, &res.new_cinfo);
            nfs_post_op_update_inode(new_dir, res.new_fattr);
      }
      return status;
}

static int nfs4_proc_rename(struct inode *old_dir, struct qstr *old_name,
            struct inode *new_dir, struct qstr *new_name)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(NFS_SERVER(old_dir),
                        _nfs4_proc_rename(old_dir, old_name,
                              new_dir, new_name),
                        &exception);
      } while (exception.retry);
      return err;
}

static int _nfs4_proc_link(struct inode *inode, struct inode *dir, struct qstr *name)
{
      struct nfs_server *server = NFS_SERVER(inode);
      struct nfs4_link_arg arg = {
            .fh     = NFS_FH(inode),
            .dir_fh = NFS_FH(dir),
            .name   = name,
            .bitmask = server->attr_bitmask,
      };
      struct nfs_fattr fattr, dir_attr;
      struct nfs4_link_res res = {
            .server = server,
            .fattr = &fattr,
            .dir_attr = &dir_attr,
      };
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LINK],
            .rpc_argp = &arg,
            .rpc_resp = &res,
      };
      int               status;

      nfs_fattr_init(res.fattr);
      nfs_fattr_init(res.dir_attr);
      status = rpc_call_sync(server->client, &msg, 0);
      if (!status) {
            update_changeattr(dir, &res.cinfo);
            nfs_post_op_update_inode(dir, res.dir_attr);
            nfs_post_op_update_inode(inode, res.fattr);
      }

      return status;
}

static int nfs4_proc_link(struct inode *inode, struct inode *dir, struct qstr *name)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(NFS_SERVER(inode),
                        _nfs4_proc_link(inode, dir, name),
                        &exception);
      } while (exception.retry);
      return err;
}

static int _nfs4_proc_symlink(struct inode *dir, struct qstr *name,
            struct qstr *path, struct iattr *sattr, struct nfs_fh *fhandle,
            struct nfs_fattr *fattr)
{
      struct nfs_server *server = NFS_SERVER(dir);
      struct nfs_fattr dir_fattr;
      struct nfs4_create_arg arg = {
            .dir_fh = NFS_FH(dir),
            .server = server,
            .name = name,
            .attrs = sattr,
            .ftype = NF4LNK,
            .bitmask = server->attr_bitmask,
      };
      struct nfs4_create_res res = {
            .server = server,
            .fh = fhandle,
            .fattr = fattr,
            .dir_fattr = &dir_fattr,
      };
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SYMLINK],
            .rpc_argp = &arg,
            .rpc_resp = &res,
      };
      int               status;

      if (path->len > NFS4_MAXPATHLEN)
            return -ENAMETOOLONG;
      arg.u.symlink = path;
      nfs_fattr_init(fattr);
      nfs_fattr_init(&dir_fattr);
      
      status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
      if (!status)
            update_changeattr(dir, &res.dir_cinfo);
      nfs_post_op_update_inode(dir, res.dir_fattr);
      return status;
}

static int nfs4_proc_symlink(struct inode *dir, struct qstr *name,
            struct qstr *path, struct iattr *sattr, struct nfs_fh *fhandle,
            struct nfs_fattr *fattr)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(NFS_SERVER(dir),
                        _nfs4_proc_symlink(dir, name, path, sattr,
                              fhandle, fattr),
                        &exception);
      } while (exception.retry);
      return err;
}

static int _nfs4_proc_mkdir(struct inode *dir, struct dentry *dentry,
            struct iattr *sattr)
{
      struct nfs_server *server = NFS_SERVER(dir);
      struct nfs_fh fhandle;
      struct nfs_fattr fattr, dir_fattr;
      struct nfs4_create_arg arg = {
            .dir_fh = NFS_FH(dir),
            .server = server,
            .name = &dentry->d_name,
            .attrs = sattr,
            .ftype = NF4DIR,
            .bitmask = server->attr_bitmask,
      };
      struct nfs4_create_res res = {
            .server = server,
            .fh = &fhandle,
            .fattr = &fattr,
            .dir_fattr = &dir_fattr,
      };
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_CREATE],
            .rpc_argp = &arg,
            .rpc_resp = &res,
      };
      int               status;

      nfs_fattr_init(&fattr);
      nfs_fattr_init(&dir_fattr);
      
      status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
      if (!status) {
            update_changeattr(dir, &res.dir_cinfo);
            nfs_post_op_update_inode(dir, res.dir_fattr);
            status = nfs_instantiate(dentry, &fhandle, &fattr);
      }
      return status;
}

static int nfs4_proc_mkdir(struct inode *dir, struct dentry *dentry,
            struct iattr *sattr)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(NFS_SERVER(dir),
                        _nfs4_proc_mkdir(dir, dentry, sattr),
                        &exception);
      } while (exception.retry);
      return err;
}

static int _nfs4_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
                  u64 cookie, struct page *page, unsigned int count, int plus)
{
      struct inode            *dir = dentry->d_inode;
      struct nfs4_readdir_arg args = {
            .fh = NFS_FH(dir),
            .pages = &page,
            .pgbase = 0,
            .count = count,
            .bitmask = NFS_SERVER(dentry->d_inode)->attr_bitmask,
      };
      struct nfs4_readdir_res res;
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READDIR],
            .rpc_argp = &args,
            .rpc_resp = &res,
            .rpc_cred = cred,
      };
      int               status;

      dprintk("%s: dentry = %s/%s, cookie = %Lu\n", __FUNCTION__,
                  dentry->d_parent->d_name.name,
                  dentry->d_name.name,
                  (unsigned long long)cookie);
      lock_kernel();
      nfs4_setup_readdir(cookie, NFS_COOKIEVERF(dir), dentry, &args);
      res.pgbase = args.pgbase;
      status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
      if (status == 0)
            memcpy(NFS_COOKIEVERF(dir), res.verifier.data, NFS4_VERIFIER_SIZE);
      unlock_kernel();
      dprintk("%s: returns %d\n", __FUNCTION__, status);
      return status;
}

static int nfs4_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
                  u64 cookie, struct page *page, unsigned int count, int plus)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(NFS_SERVER(dentry->d_inode),
                        _nfs4_proc_readdir(dentry, cred, cookie,
                              page, count, plus),
                        &exception);
      } while (exception.retry);
      return err;
}

static int _nfs4_proc_mknod(struct inode *dir, struct dentry *dentry,
            struct iattr *sattr, dev_t rdev)
{
      struct nfs_server *server = NFS_SERVER(dir);
      struct nfs_fh fh;
      struct nfs_fattr fattr, dir_fattr;
      struct nfs4_create_arg arg = {
            .dir_fh = NFS_FH(dir),
            .server = server,
            .name = &dentry->d_name,
            .attrs = sattr,
            .bitmask = server->attr_bitmask,
      };
      struct nfs4_create_res res = {
            .server = server,
            .fh = &fh,
            .fattr = &fattr,
            .dir_fattr = &dir_fattr,
      };
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_CREATE],
            .rpc_argp = &arg,
            .rpc_resp = &res,
      };
      int               status;
      int                     mode = sattr->ia_mode;

      nfs_fattr_init(&fattr);
      nfs_fattr_init(&dir_fattr);

      BUG_ON(!(sattr->ia_valid & ATTR_MODE));
      BUG_ON(!S_ISFIFO(mode) && !S_ISBLK(mode) && !S_ISCHR(mode) && !S_ISSOCK(mode));
      if (S_ISFIFO(mode))
            arg.ftype = NF4FIFO;
      else if (S_ISBLK(mode)) {
            arg.ftype = NF4BLK;
            arg.u.device.specdata1 = MAJOR(rdev);
            arg.u.device.specdata2 = MINOR(rdev);
      }
      else if (S_ISCHR(mode)) {
            arg.ftype = NF4CHR;
            arg.u.device.specdata1 = MAJOR(rdev);
            arg.u.device.specdata2 = MINOR(rdev);
      }
      else
            arg.ftype = NF4SOCK;
      
      status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
      if (status == 0) {
            update_changeattr(dir, &res.dir_cinfo);
            nfs_post_op_update_inode(dir, res.dir_fattr);
            status = nfs_instantiate(dentry, &fh, &fattr);
      }
      return status;
}

static int nfs4_proc_mknod(struct inode *dir, struct dentry *dentry,
            struct iattr *sattr, dev_t rdev)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(NFS_SERVER(dir),
                        _nfs4_proc_mknod(dir, dentry, sattr, rdev),
                        &exception);
      } while (exception.retry);
      return err;
}

static int _nfs4_proc_statfs(struct nfs_server *server, struct nfs_fh *fhandle,
             struct nfs_fsstat *fsstat)
{
      struct nfs4_statfs_arg args = {
            .fh = fhandle,
            .bitmask = server->attr_bitmask,
      };
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_STATFS],
            .rpc_argp = &args,
            .rpc_resp = fsstat,
      };

      nfs_fattr_init(fsstat->fattr);
      return rpc_call_sync(server->client, &msg, 0);
}

static int nfs4_proc_statfs(struct nfs_server *server, struct nfs_fh *fhandle, struct nfs_fsstat *fsstat)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(server,
                        _nfs4_proc_statfs(server, fhandle, fsstat),
                        &exception);
      } while (exception.retry);
      return err;
}

static int _nfs4_do_fsinfo(struct nfs_server *server, struct nfs_fh *fhandle,
            struct nfs_fsinfo *fsinfo)
{
      struct nfs4_fsinfo_arg args = {
            .fh = fhandle,
            .bitmask = server->attr_bitmask,
      };
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_FSINFO],
            .rpc_argp = &args,
            .rpc_resp = fsinfo,
      };

      return rpc_call_sync(server->client, &msg, 0);
}

static int nfs4_do_fsinfo(struct nfs_server *server, struct nfs_fh *fhandle, struct nfs_fsinfo *fsinfo)
{
      struct nfs4_exception exception = { };
      int err;

      do {
            err = nfs4_handle_exception(server,
                        _nfs4_do_fsinfo(server, fhandle, fsinfo),
                        &exception);
      } while (exception.retry);
      return err;
}

static int nfs4_proc_fsinfo(struct nfs_server *server, struct nfs_fh *fhandle, struct nfs_fsinfo *fsinfo)
{
      nfs_fattr_init(fsinfo->fattr);
      return nfs4_do_fsinfo(server, fhandle, fsinfo);
}

static int _nfs4_proc_pathconf(struct nfs_server *server, struct nfs_fh *fhandle,
            struct nfs_pathconf *pathconf)
{
      struct nfs4_pathconf_arg args = {
            .fh = fhandle,
            .bitmask = server->attr_bitmask,
      };
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_PATHCONF],
            .rpc_argp = &args,
            .rpc_resp = pathconf,
      };

      /* None of the pathconf attributes are mandatory to implement */
      if ((args.bitmask[0] & nfs4_pathconf_bitmap[0]) == 0) {
            memset(pathconf, 0, sizeof(*pathconf));
            return 0;
      }

      nfs_fattr_init(pathconf->fattr);
      return rpc_call_sync(server->client, &msg, 0);
}

static int nfs4_proc_pathconf(struct nfs_server *server, struct nfs_fh *fhandle,
            struct nfs_pathconf *pathconf)
{
      struct nfs4_exception exception = { };
      int err;

      do {
            err = nfs4_handle_exception(server,
                        _nfs4_proc_pathconf(server, fhandle, pathconf),
                        &exception);
      } while (exception.retry);
      return err;
}

static int nfs4_read_done(struct rpc_task *task, struct nfs_read_data *data)
{
      struct nfs_server *server = NFS_SERVER(data->inode);

      if (nfs4_async_handle_error(task, server) == -EAGAIN) {
            rpc_restart_call(task);
            return -EAGAIN;
      }
      if (task->tk_status > 0)
            renew_lease(server, data->timestamp);
      return 0;
}

static void nfs4_proc_read_setup(struct nfs_read_data *data)
{
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ],
            .rpc_argp = &data->args,
            .rpc_resp = &data->res,
            .rpc_cred = data->cred,
      };

      data->timestamp   = jiffies;

      rpc_call_setup(&data->task, &msg, 0);
}

static int nfs4_write_done(struct rpc_task *task, struct nfs_write_data *data)
{
      struct inode *inode = data->inode;
      
      if (nfs4_async_handle_error(task, NFS_SERVER(inode)) == -EAGAIN) {
            rpc_restart_call(task);
            return -EAGAIN;
      }
      if (task->tk_status >= 0) {
            renew_lease(NFS_SERVER(inode), data->timestamp);
            nfs_post_op_update_inode(inode, data->res.fattr);
      }
      return 0;
}

static void nfs4_proc_write_setup(struct nfs_write_data *data, int how)
{
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_WRITE],
            .rpc_argp = &data->args,
            .rpc_resp = &data->res,
            .rpc_cred = data->cred,
      };
      struct inode *inode = data->inode;
      struct nfs_server *server = NFS_SERVER(inode);
      int stable;
      
      if (how & FLUSH_STABLE) {
            if (!NFS_I(inode)->ncommit)
                  stable = NFS_FILE_SYNC;
            else
                  stable = NFS_DATA_SYNC;
      } else
            stable = NFS_UNSTABLE;
      data->args.stable = stable;
      data->args.bitmask = server->attr_bitmask;
      data->res.server = server;

      data->timestamp   = jiffies;

      /* Finalize the task. */
      rpc_call_setup(&data->task, &msg, 0);
}

static int nfs4_commit_done(struct rpc_task *task, struct nfs_write_data *data)
{
      struct inode *inode = data->inode;
      
      if (nfs4_async_handle_error(task, NFS_SERVER(inode)) == -EAGAIN) {
            rpc_restart_call(task);
            return -EAGAIN;
      }
      if (task->tk_status >= 0)
            nfs_post_op_update_inode(inode, data->res.fattr);
      return 0;
}

static void nfs4_proc_commit_setup(struct nfs_write_data *data, int how)
{
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_COMMIT],
            .rpc_argp = &data->args,
            .rpc_resp = &data->res,
            .rpc_cred = data->cred,
      };    
      struct nfs_server *server = NFS_SERVER(data->inode);
      
      data->args.bitmask = server->attr_bitmask;
      data->res.server = server;

      rpc_call_setup(&data->task, &msg, 0);
}

/*
 * nfs4_proc_async_renew(): This is not one of the nfs_rpc_ops; it is a special
 * standalone procedure for queueing an asynchronous RENEW.
 */
static void nfs4_renew_done(struct rpc_task *task, void *data)
{
      struct nfs4_client *clp = (struct nfs4_client *)task->tk_msg.rpc_argp;
      unsigned long timestamp = (unsigned long)data;

      if (task->tk_status < 0) {
            switch (task->tk_status) {
                  case -NFS4ERR_STALE_CLIENTID:
                  case -NFS4ERR_EXPIRED:
                  case -NFS4ERR_CB_PATH_DOWN:
                        nfs4_schedule_state_recovery(clp);
            }
            return;
      }
      spin_lock(&clp->cl_lock);
      if (time_before(clp->cl_last_renewal,timestamp))
            clp->cl_last_renewal = timestamp;
      spin_unlock(&clp->cl_lock);
}

static const struct rpc_call_ops nfs4_renew_ops = {
      .rpc_call_done = nfs4_renew_done,
};

int nfs4_proc_async_renew(struct nfs4_client *clp, struct rpc_cred *cred)
{
      struct rpc_message msg = {
            .rpc_proc   = &nfs4_procedures[NFSPROC4_CLNT_RENEW],
            .rpc_argp   = clp,
            .rpc_cred   = cred,
      };

      return rpc_call_async(clp->cl_rpcclient, &msg, RPC_TASK_SOFT,
                  &nfs4_renew_ops, (void *)jiffies);
}

int nfs4_proc_renew(struct nfs4_client *clp, struct rpc_cred *cred)
{
      struct rpc_message msg = {
            .rpc_proc   = &nfs4_procedures[NFSPROC4_CLNT_RENEW],
            .rpc_argp   = clp,
            .rpc_cred   = cred,
      };
      unsigned long now = jiffies;
      int status;

      status = rpc_call_sync(clp->cl_rpcclient, &msg, 0);
      if (status < 0)
            return status;
      spin_lock(&clp->cl_lock);
      if (time_before(clp->cl_last_renewal,now))
            clp->cl_last_renewal = now;
      spin_unlock(&clp->cl_lock);
      return 0;
}

static inline int nfs4_server_supports_acls(struct nfs_server *server)
{
      return (server->caps & NFS_CAP_ACLS)
            && (server->acl_bitmask & ACL4_SUPPORT_ALLOW_ACL)
            && (server->acl_bitmask & ACL4_SUPPORT_DENY_ACL);
}

/* Assuming that XATTR_SIZE_MAX is a multiple of PAGE_CACHE_SIZE, and that
 * it's OK to put sizeof(void) * (XATTR_SIZE_MAX/PAGE_CACHE_SIZE) bytes on
 * the stack.
 */
#define NFS4ACL_MAXPAGES (XATTR_SIZE_MAX >> PAGE_CACHE_SHIFT)

static void buf_to_pages(const void *buf, size_t buflen,
            struct page **pages, unsigned int *pgbase)
{
      const void *p = buf;

      *pgbase = offset_in_page(buf);
      p -= *pgbase;
      while (p < buf + buflen) {
            *(pages++) = virt_to_page(p);
            p += PAGE_CACHE_SIZE;
      }
}

struct nfs4_cached_acl {
      int cached;
      size_t len;
      char data[0];
};

static void nfs4_set_cached_acl(struct inode *inode, struct nfs4_cached_acl *acl)
{
      struct nfs_inode *nfsi = NFS_I(inode);

      spin_lock(&inode->i_lock);
      kfree(nfsi->nfs4_acl);
      nfsi->nfs4_acl = acl;
      spin_unlock(&inode->i_lock);
}

static void nfs4_zap_acl_attr(struct inode *inode)
{
      nfs4_set_cached_acl(inode, NULL);
}

static inline ssize_t nfs4_read_cached_acl(struct inode *inode, char *buf, size_t buflen)
{
      struct nfs_inode *nfsi = NFS_I(inode);
      struct nfs4_cached_acl *acl;
      int ret = -ENOENT;

      spin_lock(&inode->i_lock);
      acl = nfsi->nfs4_acl;
      if (acl == NULL)
            goto out;
      if (buf == NULL) /* user is just asking for length */
            goto out_len;
      if (acl->cached == 0)
            goto out;
      ret = -ERANGE; /* see getxattr(2) man page */
      if (acl->len > buflen)
            goto out;
      memcpy(buf, acl->data, acl->len);
out_len:
      ret = acl->len;
out:
      spin_unlock(&inode->i_lock);
      return ret;
}

static void nfs4_write_cached_acl(struct inode *inode, const char *buf, size_t acl_len)
{
      struct nfs4_cached_acl *acl;

      if (buf && acl_len <= PAGE_SIZE) {
            acl = kmalloc(sizeof(*acl) + acl_len, GFP_KERNEL);
            if (acl == NULL)
                  goto out;
            acl->cached = 1;
            memcpy(acl->data, buf, acl_len);
      } else {
            acl = kmalloc(sizeof(*acl), GFP_KERNEL);
            if (acl == NULL)
                  goto out;
            acl->cached = 0;
      }
      acl->len = acl_len;
out:
      nfs4_set_cached_acl(inode, acl);
}

static ssize_t __nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t buflen)
{
      struct page *pages[NFS4ACL_MAXPAGES];
      struct nfs_getaclargs args = {
            .fh = NFS_FH(inode),
            .acl_pages = pages,
            .acl_len = buflen,
      };
      size_t resp_len = buflen;
      void *resp_buf;
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_GETACL],
            .rpc_argp = &args,
            .rpc_resp = &resp_len,
      };
      struct page *localpage = NULL;
      int ret;

      if (buflen < PAGE_SIZE) {
            /* As long as we're doing a round trip to the server anyway,
             * let's be prepared for a page of acl data. */
            localpage = alloc_page(GFP_KERNEL);
            resp_buf = page_address(localpage);
            if (localpage == NULL)
                  return -ENOMEM;
            args.acl_pages[0] = localpage;
            args.acl_pgbase = 0;
            resp_len = args.acl_len = PAGE_SIZE;
      } else {
            resp_buf = buf;
            buf_to_pages(buf, buflen, args.acl_pages, &args.acl_pgbase);
      }
      ret = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
      if (ret)
            goto out_free;
      if (resp_len > args.acl_len)
            nfs4_write_cached_acl(inode, NULL, resp_len);
      else
            nfs4_write_cached_acl(inode, resp_buf, resp_len);
      if (buf) {
            ret = -ERANGE;
            if (resp_len > buflen)
                  goto out_free;
            if (localpage)
                  memcpy(buf, resp_buf, resp_len);
      }
      ret = resp_len;
out_free:
      if (localpage)
            __free_page(localpage);
      return ret;
}

static ssize_t nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t buflen)
{
      struct nfs4_exception exception = { };
      ssize_t ret;
      do {
            ret = __nfs4_get_acl_uncached(inode, buf, buflen);
            if (ret >= 0)
                  break;
            ret = nfs4_handle_exception(NFS_SERVER(inode), ret, &exception);
      } while (exception.retry);
      return ret;
}

static ssize_t nfs4_proc_get_acl(struct inode *inode, void *buf, size_t buflen)
{
      struct nfs_server *server = NFS_SERVER(inode);
      int ret;

      if (!nfs4_server_supports_acls(server))
            return -EOPNOTSUPP;
      ret = nfs_revalidate_inode(server, inode);
      if (ret < 0)
            return ret;
      ret = nfs4_read_cached_acl(inode, buf, buflen);
      if (ret != -ENOENT)
            return ret;
      return nfs4_get_acl_uncached(inode, buf, buflen);
}

static int __nfs4_proc_set_acl(struct inode *inode, const void *buf, size_t buflen)
{
      struct nfs_server *server = NFS_SERVER(inode);
      struct page *pages[NFS4ACL_MAXPAGES];
      struct nfs_setaclargs arg = {
            .fh         = NFS_FH(inode),
            .acl_pages  = pages,
            .acl_len    = buflen,
      };
      struct rpc_message msg = {
            .rpc_proc   = &nfs4_procedures[NFSPROC4_CLNT_SETACL],
            .rpc_argp   = &arg,
            .rpc_resp   = NULL,
      };
      int ret;

      if (!nfs4_server_supports_acls(server))
            return -EOPNOTSUPP;
      nfs_inode_return_delegation(inode);
      buf_to_pages(buf, buflen, arg.acl_pages, &arg.acl_pgbase);
      ret = rpc_call_sync(NFS_SERVER(inode)->client, &msg, 0);
      if (ret == 0)
            nfs4_write_cached_acl(inode, buf, buflen);
      return ret;
}

static int nfs4_proc_set_acl(struct inode *inode, const void *buf, size_t buflen)
{
      struct nfs4_exception exception = { };
      int err;
      do {
            err = nfs4_handle_exception(NFS_SERVER(inode),
                        __nfs4_proc_set_acl(inode, buf, buflen),
                        &exception);
      } while (exception.retry);
      return err;
}

static int
nfs4_async_handle_error(struct rpc_task *task, const struct nfs_server *server)
{
      struct nfs4_client *clp = server->nfs4_state;

      if (!clp || task->tk_status >= 0)
            return 0;
      switch(task->tk_status) {
            case -NFS4ERR_STALE_CLIENTID:
            case -NFS4ERR_STALE_STATEID:
            case -NFS4ERR_EXPIRED:
                  rpc_sleep_on(&clp->cl_rpcwaitq, task, NULL, NULL);
                  nfs4_schedule_state_recovery(clp);
                  if (test_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) == 0)
                        rpc_wake_up_task(task);
                  task->tk_status = 0;
                  return -EAGAIN;
            case -NFS4ERR_DELAY:
                  nfs_inc_server_stats((struct nfs_server *) server,
                                    NFSIOS_DELAY);
            case -NFS4ERR_GRACE:
                  rpc_delay(task, NFS4_POLL_RETRY_MAX);
                  task->tk_status = 0;
                  return -EAGAIN;
            case -NFS4ERR_OLD_STATEID:
                  task->tk_status = 0;
                  return -EAGAIN;
      }
      task->tk_status = nfs4_map_errors(task->tk_status);
      return 0;
}

static int nfs4_wait_bit_interruptible(void *word)
{
      if (signal_pending(current))
            return -ERESTARTSYS;
      schedule();
      return 0;
}

static int nfs4_wait_clnt_recover(struct rpc_clnt *clnt, struct nfs4_client *clp)
{
      sigset_t oldset;
      int res;

      might_sleep();

      rpc_clnt_sigmask(clnt, &oldset);
      res = wait_on_bit(&clp->cl_state, NFS4CLNT_STATE_RECOVER,
                  nfs4_wait_bit_interruptible,
                  TASK_INTERRUPTIBLE);
      rpc_clnt_sigunmask(clnt, &oldset);
      return res;
}

static int nfs4_delay(struct rpc_clnt *clnt, long *timeout)
{
      sigset_t oldset;
      int res = 0;

      might_sleep();

      if (*timeout <= 0)
            *timeout = NFS4_POLL_RETRY_MIN;
      if (*timeout > NFS4_POLL_RETRY_MAX)
            *timeout = NFS4_POLL_RETRY_MAX;
      rpc_clnt_sigmask(clnt, &oldset);
      if (clnt->cl_intr) {
            schedule_timeout_interruptible(*timeout);
            if (signalled())
                  res = -ERESTARTSYS;
      } else
            schedule_timeout_uninterruptible(*timeout);
      rpc_clnt_sigunmask(clnt, &oldset);
      *timeout <<= 1;
      return res;
}

/* This is the error handling routine for processes that are allowed
 * to sleep.
 */
int nfs4_handle_exception(const struct nfs_server *server, int errorcode, struct nfs4_exception *exception)
{
      struct nfs4_client *clp = server->nfs4_state;
      int ret = errorcode;

      exception->retry = 0;
      switch(errorcode) {
            case 0:
                  return 0;
            case -NFS4ERR_STALE_CLIENTID:
            case -NFS4ERR_STALE_STATEID:
            case -NFS4ERR_EXPIRED:
                  nfs4_schedule_state_recovery(clp);
                  ret = nfs4_wait_clnt_recover(server->client, clp);
                  if (ret == 0)
                        exception->retry = 1;
                  break;
            case -NFS4ERR_GRACE:
            case -NFS4ERR_DELAY:
                  ret = nfs4_delay(server->client, &exception->timeout);
                  if (ret != 0)
                        break;
            case -NFS4ERR_OLD_STATEID:
                  exception->retry = 1;
      }
      /* We failed to handle the error */
      return nfs4_map_errors(ret);
}

int nfs4_proc_setclientid(struct nfs4_client *clp, u32 program, unsigned short port, struct rpc_cred *cred)
{
      nfs4_verifier sc_verifier;
      struct nfs4_setclientid setclientid = {
            .sc_verifier = &sc_verifier,
            .sc_prog = program,
      };
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SETCLIENTID],
            .rpc_argp = &setclientid,
            .rpc_resp = clp,
            .rpc_cred = cred,
      };
      u32 *p;
      int loop = 0;
      int status;

      p = (u32*)sc_verifier.data;
      *p++ = htonl((u32)clp->cl_boot_time.tv_sec);
      *p = htonl((u32)clp->cl_boot_time.tv_nsec);

      for(;;) {
            setclientid.sc_name_len = scnprintf(setclientid.sc_name,
                        sizeof(setclientid.sc_name), "%s/%u.%u.%u.%u %s %u",
                        clp->cl_ipaddr, NIPQUAD(clp->cl_addr.s_addr),
                        cred->cr_ops->cr_name,
                        clp->cl_id_uniquifier);
            setclientid.sc_netid_len = scnprintf(setclientid.sc_netid,
                        sizeof(setclientid.sc_netid), "tcp");
            setclientid.sc_uaddr_len = scnprintf(setclientid.sc_uaddr,
                        sizeof(setclientid.sc_uaddr), "%s.%d.%d",
                        clp->cl_ipaddr, port >> 8, port & 255);

            status = rpc_call_sync(clp->cl_rpcclient, &msg, 0);
            if (status != -NFS4ERR_CLID_INUSE)
                  break;
            if (signalled())
                  break;
            if (loop++ & 1)
                  ssleep(clp->cl_lease_time + 1);
            else
                  if (++clp->cl_id_uniquifier == 0)
                        break;
      }
      return status;
}

static int _nfs4_proc_setclientid_confirm(struct nfs4_client *clp, struct rpc_cred *cred)
{
      struct nfs_fsinfo fsinfo;
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SETCLIENTID_CONFIRM],
            .rpc_argp = clp,
            .rpc_resp = &fsinfo,
            .rpc_cred = cred,
      };
      unsigned long now;
      int status;

      now = jiffies;
      status = rpc_call_sync(clp->cl_rpcclient, &msg, 0);
      if (status == 0) {
            spin_lock(&clp->cl_lock);
            clp->cl_lease_time = fsinfo.lease_time * HZ;
            clp->cl_last_renewal = now;
            clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
            spin_unlock(&clp->cl_lock);
      }
      return status;
}

int nfs4_proc_setclientid_confirm(struct nfs4_client *clp, struct rpc_cred *cred)
{
      long timeout;
      int err;
      do {
            err = _nfs4_proc_setclientid_confirm(clp, cred);
            switch (err) {
                  case 0:
                        return err;
                  case -NFS4ERR_RESOURCE:
                        /* The IBM lawyers misread another document! */
                  case -NFS4ERR_DELAY:
                        err = nfs4_delay(clp->cl_rpcclient, &timeout);
            }
      } while (err == 0);
      return err;
}

struct nfs4_delegreturndata {
      struct nfs4_delegreturnargs args;
      struct nfs4_delegreturnres res;
      struct nfs_fh fh;
      nfs4_stateid stateid;
      struct rpc_cred *cred;
      unsigned long timestamp;
      struct nfs_fattr fattr;
      int rpc_status;
};

static void nfs4_delegreturn_prepare(struct rpc_task *task, void *calldata)
{
      struct nfs4_delegreturndata *data = calldata;
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_DELEGRETURN],
            .rpc_argp = &data->args,
            .rpc_resp = &data->res,
            .rpc_cred = data->cred,
      };
      nfs_fattr_init(data->res.fattr);
      rpc_call_setup(task, &msg, 0);
}

static void nfs4_delegreturn_done(struct rpc_task *task, void *calldata)
{
      struct nfs4_delegreturndata *data = calldata;
      data->rpc_status = task->tk_status;
      if (data->rpc_status == 0)
            renew_lease(data->res.server, data->timestamp);
}

static void nfs4_delegreturn_release(void *calldata)
{
      struct nfs4_delegreturndata *data = calldata;

      put_rpccred(data->cred);
      kfree(calldata);
}

static const struct rpc_call_ops nfs4_delegreturn_ops = {
      .rpc_call_prepare = nfs4_delegreturn_prepare,
      .rpc_call_done = nfs4_delegreturn_done,
      .rpc_release = nfs4_delegreturn_release,
};

static int _nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, const nfs4_stateid *stateid)
{
      struct nfs4_delegreturndata *data;
      struct nfs_server *server = NFS_SERVER(inode);
      struct rpc_task *task;
      int status;

      data = kmalloc(sizeof(*data), GFP_KERNEL);
      if (data == NULL)
            return -ENOMEM;
      data->args.fhandle = &data->fh;
      data->args.stateid = &data->stateid;
      data->args.bitmask = server->attr_bitmask;
      nfs_copy_fh(&data->fh, NFS_FH(inode));
      memcpy(&data->stateid, stateid, sizeof(data->stateid));
      data->res.fattr = &data->fattr;
      data->res.server = server;
      data->cred = get_rpccred(cred);
      data->timestamp = jiffies;
      data->rpc_status = 0;

      task = rpc_run_task(NFS_CLIENT(inode), RPC_TASK_ASYNC, &nfs4_delegreturn_ops, data);
      if (IS_ERR(task))
            return PTR_ERR(task);
      status = nfs4_wait_for_completion_rpc_task(task);
      if (status == 0) {
            status = data->rpc_status;
            if (status == 0)
                  nfs_post_op_update_inode(inode, &data->fattr);
      }
      rpc_release_task(task);
      return status;
}

int nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, const nfs4_stateid *stateid)
{
      struct nfs_server *server = NFS_SERVER(inode);
      struct nfs4_exception exception = { };
      int err;
      do {
            err = _nfs4_proc_delegreturn(inode, cred, stateid);
            switch (err) {
                  case -NFS4ERR_STALE_STATEID:
                  case -NFS4ERR_EXPIRED:
                        nfs4_schedule_state_recovery(server->nfs4_state);
                  case 0:
                        return 0;
            }
            err = nfs4_handle_exception(server, err, &exception);
      } while (exception.retry);
      return err;
}

#define NFS4_LOCK_MINTIMEOUT (1 * HZ)
#define NFS4_LOCK_MAXTIMEOUT (30 * HZ)

/* 
 * sleep, with exponential backoff, and retry the LOCK operation. 
 */
static unsigned long
nfs4_set_lock_task_retry(unsigned long timeout)
{
      schedule_timeout_interruptible(timeout);
      timeout <<= 1;
      if (timeout > NFS4_LOCK_MAXTIMEOUT)
            return NFS4_LOCK_MAXTIMEOUT;
      return timeout;
}

static int _nfs4_proc_getlk(struct nfs4_state *state, int cmd, struct file_lock *request)
{
      struct inode *inode = state->inode;
      struct nfs_server *server = NFS_SERVER(inode);
      struct nfs4_client *clp = server->nfs4_state;
      struct nfs_lockt_args arg = {
            .fh = NFS_FH(inode),
            .fl = request,
      };
      struct nfs_lockt_res res = {
            .denied = request,
      };
      struct rpc_message msg = {
            .rpc_proc   = &nfs4_procedures[NFSPROC4_CLNT_LOCKT],
            .rpc_argp       = &arg,
            .rpc_resp       = &res,
            .rpc_cred   = state->owner->so_cred,
      };
      struct nfs4_lock_state *lsp;
      int status;

      down_read(&clp->cl_sem);
      arg.lock_owner.clientid = clp->cl_clientid;
      status = nfs4_set_lock_state(state, request);
      if (status != 0)
            goto out;
      lsp = request->fl_u.nfs4_fl.owner;
      arg.lock_owner.id = lsp->ls_id; 
      status = rpc_call_sync(server->client, &msg, 0);
      switch (status) {
            case 0:
                  request->fl_type = F_UNLCK;
                  break;
            case -NFS4ERR_DENIED:
                  status = 0;
      }
out:
      up_read(&clp->cl_sem);
      return status;
}

static int nfs4_proc_getlk(struct nfs4_state *state, int cmd, struct file_lock *request)
{
      struct nfs4_exception exception = { };
      int err;

      do {
            err = nfs4_handle_exception(NFS_SERVER(state->inode),
                        _nfs4_proc_getlk(state, cmd, request),
                        &exception);
      } while (exception.retry);
      return err;
}

static int do_vfs_lock(struct file *file, struct file_lock *fl)
{
      int res = 0;
      switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
            case FL_POSIX:
                  res = posix_lock_file_wait(file, fl);
                  break;
            case FL_FLOCK:
                  res = flock_lock_file_wait(file, fl);
                  break;
            default:
                  BUG();
      }
      return res;
}

struct nfs4_unlockdata {
      struct nfs_locku_args arg;
      struct nfs_locku_res res;
      struct nfs4_lock_state *lsp;
      struct nfs_open_context *ctx;
      struct file_lock fl;
      const struct nfs_server *server;
      unsigned long timestamp;
};

static struct nfs4_unlockdata *nfs4_alloc_unlockdata(struct file_lock *fl,
            struct nfs_open_context *ctx,
            struct nfs4_lock_state *lsp,
            struct nfs_seqid *seqid)
{
      struct nfs4_unlockdata *p;
      struct inode *inode = lsp->ls_state->inode;

      p = kmalloc(sizeof(*p), GFP_KERNEL);
      if (p == NULL)
            return NULL;
      p->arg.fh = NFS_FH(inode);
      p->arg.fl = &p->fl;
      p->arg.seqid = seqid;
      p->arg.stateid = &lsp->ls_stateid;
      p->lsp = lsp;
      atomic_inc(&lsp->ls_count);
      /* Ensure we don't close file until we're done freeing locks! */
      p->ctx = get_nfs_open_context(ctx);
      memcpy(&p->fl, fl, sizeof(p->fl));
      p->server = NFS_SERVER(inode);
      return p;
}

static void nfs4_locku_release_calldata(void *data)
{
      struct nfs4_unlockdata *calldata = data;
      nfs_free_seqid(calldata->arg.seqid);
      nfs4_put_lock_state(calldata->lsp);
      put_nfs_open_context(calldata->ctx);
      kfree(calldata);
}

static void nfs4_locku_done(struct rpc_task *task, void *data)
{
      struct nfs4_unlockdata *calldata = data;

      if (RPC_ASSASSINATED(task))
            return;
      nfs_increment_lock_seqid(task->tk_status, calldata->arg.seqid);
      switch (task->tk_status) {
            case 0:
                  memcpy(calldata->lsp->ls_stateid.data,
                              calldata->res.stateid.data,
                              sizeof(calldata->lsp->ls_stateid.data));
                  renew_lease(calldata->server, calldata->timestamp);
                  break;
            case -NFS4ERR_STALE_STATEID:
            case -NFS4ERR_EXPIRED:
                  nfs4_schedule_state_recovery(calldata->server->nfs4_state);
                  break;
            default:
                  if (nfs4_async_handle_error(task, calldata->server) == -EAGAIN) {
                        rpc_restart_call(task);
                  }
      }
}

static void nfs4_locku_prepare(struct rpc_task *task, void *data)
{
      struct nfs4_unlockdata *calldata = data;
      struct rpc_message msg = {
            .rpc_proc   = &nfs4_procedures[NFSPROC4_CLNT_LOCKU],
            .rpc_argp       = &calldata->arg,
            .rpc_resp       = &calldata->res,
            .rpc_cred   = calldata->lsp->ls_state->owner->so_cred,
      };

      if (nfs_wait_on_sequence(calldata->arg.seqid, task) != 0)
            return;
      if ((calldata->lsp->ls_flags & NFS_LOCK_INITIALIZED) == 0) {
            /* Note: exit _without_ running nfs4_locku_done */
            task->tk_action = NULL;
            return;
      }
      calldata->timestamp = jiffies;
      rpc_call_setup(task, &msg, 0);
}

static const struct rpc_call_ops nfs4_locku_ops = {
      .rpc_call_prepare = nfs4_locku_prepare,
      .rpc_call_done = nfs4_locku_done,
      .rpc_release = nfs4_locku_release_calldata,
};

static struct rpc_task *nfs4_do_unlck(struct file_lock *fl,
            struct nfs_open_context *ctx,
            struct nfs4_lock_state *lsp,
            struct nfs_seqid *seqid)
{
      struct nfs4_unlockdata *data;

      data = nfs4_alloc_unlockdata(fl, ctx, lsp, seqid);
      if (data == NULL) {
            nfs_free_seqid(seqid);
            return ERR_PTR(-ENOMEM);
      }

      return rpc_run_task(NFS_CLIENT(lsp->ls_state->inode), RPC_TASK_ASYNC, &nfs4_locku_ops, data);
}

static int nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock *request)
{
      struct nfs_seqid *seqid;
      struct nfs4_lock_state *lsp;
      struct rpc_task *task;
      int status = 0;

      status = nfs4_set_lock_state(state, request);
      /* Unlock _before_ we do the RPC call */
      request->fl_flags |= FL_EXISTS;
      if (do_vfs_lock(request->fl_file, request) == -ENOENT)
            goto out;
      if (status != 0)
            goto out;
      /* Is this a delegated lock? */
      if (test_bit(NFS_DELEGATED_STATE, &state->flags))
            goto out;
      lsp = request->fl_u.nfs4_fl.owner;
      seqid = nfs_alloc_seqid(&lsp->ls_seqid);
      status = -ENOMEM;
      if (seqid == NULL)
            goto out;
      task = nfs4_do_unlck(request, request->fl_file->private_data, lsp, seqid);
      status = PTR_ERR(task);
      if (IS_ERR(task))
            goto out;
      status = nfs4_wait_for_completion_rpc_task(task);
      rpc_release_task(task);
out:
      return status;
}

struct nfs4_lockdata {
      struct nfs_lock_args arg;
      struct nfs_lock_res res;
      struct nfs4_lock_state *lsp;
      struct nfs_open_context *ctx;
      struct file_lock fl;
      unsigned long timestamp;
      int rpc_status;
      int cancelled;
};

static struct nfs4_lockdata *nfs4_alloc_lockdata(struct file_lock *fl,
            struct nfs_open_context *ctx, struct nfs4_lock_state *lsp)
{
      struct nfs4_lockdata *p;
      struct inode *inode = lsp->ls_state->inode;
      struct nfs_server *server = NFS_SERVER(inode);

      p = kzalloc(sizeof(*p), GFP_KERNEL);
      if (p == NULL)
            return NULL;

      p->arg.fh = NFS_FH(inode);
      p->arg.fl = &p->fl;
      p->arg.lock_seqid = nfs_alloc_seqid(&lsp->ls_seqid);
      if (p->arg.lock_seqid == NULL)
            goto out_free;
      p->arg.lock_stateid = &lsp->ls_stateid;
      p->arg.lock_owner.clientid = server->nfs4_state->cl_clientid;
      p->arg.lock_owner.id = lsp->ls_id;
      p->lsp = lsp;
      atomic_inc(&lsp->ls_count);
      p->ctx = get_nfs_open_context(ctx);
      memcpy(&p->fl, fl, sizeof(p->fl));
      return p;
out_free:
      kfree(p);
      return NULL;
}

static void nfs4_lock_prepare(struct rpc_task *task, void *calldata)
{
      struct nfs4_lockdata *data = calldata;
      struct nfs4_state *state = data->lsp->ls_state;
      struct nfs4_state_owner *sp = state->owner;
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LOCK],
            .rpc_argp = &data->arg,
            .rpc_resp = &data->res,
            .rpc_cred = sp->so_cred,
      };

      if (nfs_wait_on_sequence(data->arg.lock_seqid, task) != 0)
            return;
      dprintk("%s: begin!\n", __FUNCTION__);
      /* Do we need to do an open_to_lock_owner? */
      if (!(data->arg.lock_seqid->sequence->flags & NFS_SEQID_CONFIRMED)) {
            data->arg.open_seqid = nfs_alloc_seqid(&sp->so_seqid);
            if (data->arg.open_seqid == NULL) {
                  data->rpc_status = -ENOMEM;
                  task->tk_action = NULL;
                  goto out;
            }
            data->arg.open_stateid = &state->stateid;
            data->arg.new_lock_owner = 1;
      }
      data->timestamp = jiffies;
      rpc_call_setup(task, &msg, 0);
out:
      dprintk("%s: done!, ret = %d\n", __FUNCTION__, data->rpc_status);
}

static void nfs4_lock_done(struct rpc_task *task, void *calldata)
{
      struct nfs4_lockdata *data = calldata;

      dprintk("%s: begin!\n", __FUNCTION__);

      data->rpc_status = task->tk_status;
      if (RPC_ASSASSINATED(task))
            goto out;
      if (data->arg.new_lock_owner != 0) {
            nfs_increment_open_seqid(data->rpc_status, data->arg.open_seqid);
            if (data->rpc_status == 0)
                  nfs_confirm_seqid(&data->lsp->ls_seqid, 0);
            else
                  goto out;
      }
      if (data->rpc_status == 0) {
            memcpy(data->lsp->ls_stateid.data, data->res.stateid.data,
                              sizeof(data->lsp->ls_stateid.data));
            data->lsp->ls_flags |= NFS_LOCK_INITIALIZED;
            renew_lease(NFS_SERVER(data->ctx->dentry->d_inode), data->timestamp);
      }
      nfs_increment_lock_seqid(data->rpc_status, data->arg.lock_seqid);
out:
      dprintk("%s: done, ret = %d!\n", __FUNCTION__, data->rpc_status);
}

static void nfs4_lock_release(void *calldata)
{
      struct nfs4_lockdata *data = calldata;

      dprintk("%s: begin!\n", __FUNCTION__);
      if (data->arg.open_seqid != NULL)
            nfs_free_seqid(data->arg.open_seqid);
      if (data->cancelled != 0) {
            struct rpc_task *task;
            task = nfs4_do_unlck(&data->fl, data->ctx, data->lsp,
                        data->arg.lock_seqid);
            if (!IS_ERR(task))
                  rpc_release_task(task);
            dprintk("%s: cancelling lock!\n", __FUNCTION__);
      } else
            nfs_free_seqid(data->arg.lock_seqid);
      nfs4_put_lock_state(data->lsp);
      put_nfs_open_context(data->ctx);
      kfree(data);
      dprintk("%s: done!\n", __FUNCTION__);
}

static const struct rpc_call_ops nfs4_lock_ops = {
      .rpc_call_prepare = nfs4_lock_prepare,
      .rpc_call_done = nfs4_lock_done,
      .rpc_release = nfs4_lock_release,
};

static int _nfs4_do_setlk(struct nfs4_state *state, int cmd, struct file_lock *fl, int reclaim)
{
      struct nfs4_lockdata *data;
      struct rpc_task *task;
      int ret;

      dprintk("%s: begin!\n", __FUNCTION__);
      data = nfs4_alloc_lockdata(fl, fl->fl_file->private_data,
                  fl->fl_u.nfs4_fl.owner);
      if (data == NULL)
            return -ENOMEM;
      if (IS_SETLKW(cmd))
            data->arg.block = 1;
      if (reclaim != 0)
            data->arg.reclaim = 1;
      task = rpc_run_task(NFS_CLIENT(state->inode), RPC_TASK_ASYNC,
                  &nfs4_lock_ops, data);
      if (IS_ERR(task))
            return PTR_ERR(task);
      ret = nfs4_wait_for_completion_rpc_task(task);
      if (ret == 0) {
            ret = data->rpc_status;
            if (ret == -NFS4ERR_DENIED)
                  ret = -EAGAIN;
      } else
            data->cancelled = 1;
      rpc_release_task(task);
      dprintk("%s: done, ret = %d!\n", __FUNCTION__, ret);
      return ret;
}

static int nfs4_lock_reclaim(struct nfs4_state *state, struct file_lock *request)
{
      struct nfs_server *server = NFS_SERVER(state->inode);
      struct nfs4_exception exception = { };
      int err;

      do {
            /* Cache the lock if possible... */
            if (test_bit(NFS_DELEGATED_STATE, &state->flags) != 0)
                  return 0;
            err = _nfs4_do_setlk(state, F_SETLK, request, 1);
            if (err != -NFS4ERR_DELAY)
                  break;
            nfs4_handle_exception(server, err, &exception);
      } while (exception.retry);
      return err;
}

static int nfs4_lock_expired(struct nfs4_state *state, struct file_lock *request)
{
      struct nfs_server *server = NFS_SERVER(state->inode);
      struct nfs4_exception exception = { };
      int err;

      err = nfs4_set_lock_state(state, request);
      if (err != 0)
            return err;
      do {
            if (test_bit(NFS_DELEGATED_STATE, &state->flags) != 0)
                  return 0;
            err = _nfs4_do_setlk(state, F_SETLK, request, 0);
            if (err != -NFS4ERR_DELAY)
                  break;
            nfs4_handle_exception(server, err, &exception);
      } while (exception.retry);
      return err;
}

static int _nfs4_proc_setlk(struct nfs4_state *state, int cmd, struct file_lock *request)
{
      struct nfs4_client *clp = state->owner->so_client;
      unsigned char fl_flags = request->fl_flags;
      int status;

      /* Is this a delegated open? */
      status = nfs4_set_lock_state(state, request);
      if (status != 0)
            goto out;
      request->fl_flags |= FL_ACCESS;
      status = do_vfs_lock(request->fl_file, request);
      if (status < 0)
            goto out;
      down_read(&clp->cl_sem);
      if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {
            struct nfs_inode *nfsi = NFS_I(state->inode);
            /* Yes: cache locks! */
            down_read(&nfsi->rwsem);
            /* ...but avoid races with delegation recall... */
            if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {
                  request->fl_flags = fl_flags & ~FL_SLEEP;
                  status = do_vfs_lock(request->fl_file, request);
                  up_read(&nfsi->rwsem);
                  goto out_unlock;
            }
            up_read(&nfsi->rwsem);
      }
      status = _nfs4_do_setlk(state, cmd, request, 0);
      if (status != 0)
            goto out_unlock;
      /* Note: we always want to sleep here! */
      request->fl_flags = fl_flags | FL_SLEEP;
      if (do_vfs_lock(request->fl_file, request) < 0)
            printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", __FUNCTION__);
out_unlock:
      up_read(&clp->cl_sem);
out:
      request->fl_flags = fl_flags;
      return status;
}

static int nfs4_proc_setlk(struct nfs4_state *state, int cmd, struct file_lock *request)
{
      struct nfs4_exception exception = { };
      int err;

      do {
            err = nfs4_handle_exception(NFS_SERVER(state->inode),
                        _nfs4_proc_setlk(state, cmd, request),
                        &exception);
      } while (exception.retry);
      return err;
}

static int
nfs4_proc_lock(struct file *filp, int cmd, struct file_lock *request)
{
      struct nfs_open_context *ctx;
      struct nfs4_state *state;
      unsigned long timeout = NFS4_LOCK_MINTIMEOUT;
      int status;

      /* verify open state */
      ctx = (struct nfs_open_context *)filp->private_data;
      state = ctx->state;

      if (request->fl_start < 0 || request->fl_end < 0)
            return -EINVAL;

      if (IS_GETLK(cmd))
            return nfs4_proc_getlk(state, F_GETLK, request);

      if (!(IS_SETLK(cmd) || IS_SETLKW(cmd)))
            return -EINVAL;

      if (request->fl_type == F_UNLCK)
            return nfs4_proc_unlck(state, cmd, request);

      do {
            status = nfs4_proc_setlk(state, cmd, request);
            if ((status != -EAGAIN) || IS_SETLK(cmd))
                  break;
            timeout = nfs4_set_lock_task_retry(timeout);
            status = -ERESTARTSYS;
            if (signalled())
                  break;
      } while(status < 0);
      return status;
}

int nfs4_lock_delegation_recall(struct nfs4_state *state, struct file_lock *fl)
{
      struct nfs_server *server = NFS_SERVER(state->inode);
      struct nfs4_exception exception = { };
      int err;

      err = nfs4_set_lock_state(state, fl);
      if (err != 0)
            goto out;
      do {
            err = _nfs4_do_setlk(state, F_SETLK, fl, 0);
            if (err != -NFS4ERR_DELAY)
                  break;
            err = nfs4_handle_exception(server, err, &exception);
      } while (exception.retry);
out:
      return err;
}

#define XATTR_NAME_NFSV4_ACL "system.nfs4_acl"

int nfs4_setxattr(struct dentry *dentry, const char *key, const void *buf,
            size_t buflen, int flags)
{
      struct inode *inode = dentry->d_inode;

      if (strcmp(key, XATTR_NAME_NFSV4_ACL) != 0)
            return -EOPNOTSUPP;

      if (!S_ISREG(inode->i_mode) &&
          (!S_ISDIR(inode->i_mode) || inode->i_mode & S_ISVTX))
            return -EPERM;

      return nfs4_proc_set_acl(inode, buf, buflen);
}

/* The getxattr man page suggests returning -ENODATA for unknown attributes,
 * and that's what we'll do for e.g. user attributes that haven't been set.
 * But we'll follow ext2/ext3's lead by returning -EOPNOTSUPP for unsupported
 * attributes in kernel-managed attribute namespaces. */
ssize_t nfs4_getxattr(struct dentry *dentry, const char *key, void *buf,
            size_t buflen)
{
      struct inode *inode = dentry->d_inode;

      if (strcmp(key, XATTR_NAME_NFSV4_ACL) != 0)
            return -EOPNOTSUPP;

      return nfs4_proc_get_acl(inode, buf, buflen);
}

ssize_t nfs4_listxattr(struct dentry *dentry, char *buf, size_t buflen)
{
      size_t len = strlen(XATTR_NAME_NFSV4_ACL) + 1;

      if (!nfs4_server_supports_acls(NFS_SERVER(dentry->d_inode)))
            return 0;
      if (buf && buflen < len)
            return -ERANGE;
      if (buf)
            memcpy(buf, XATTR_NAME_NFSV4_ACL, len);
      return len;
}

int nfs4_proc_fs_locations(struct inode *dir, struct dentry *dentry,
            struct nfs4_fs_locations *fs_locations, struct page *page)
{
      struct nfs_server *server = NFS_SERVER(dir);
      u32 bitmask[2] = {
            [0] = FATTR4_WORD0_FSID | FATTR4_WORD0_FS_LOCATIONS,
            [1] = FATTR4_WORD1_MOUNTED_ON_FILEID,
      };
      struct nfs4_fs_locations_arg args = {
            .dir_fh = NFS_FH(dir),
            .name = &dentry->d_name,
            .page = page,
            .bitmask = bitmask,
      };
      struct rpc_message msg = {
            .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_FS_LOCATIONS],
            .rpc_argp = &args,
            .rpc_resp = fs_locations,
      };
      int status;

      dprintk("%s: start\n", __FUNCTION__);
      fs_locations->fattr.valid = 0;
      fs_locations->server = server;
      fs_locations->nlocations = 0;
      status = rpc_call_sync(server->client, &msg, 0);
      dprintk("%s: returned status = %d\n", __FUNCTION__, status);
      return status;
}

struct nfs4_state_recovery_ops nfs4_reboot_recovery_ops = {
      .recover_open     = nfs4_open_reclaim,
      .recover_lock     = nfs4_lock_reclaim,
};

struct nfs4_state_recovery_ops nfs4_network_partition_recovery_ops = {
      .recover_open     = nfs4_open_expired,
      .recover_lock     = nfs4_lock_expired,
};

static struct inode_operations nfs4_file_inode_operations = {
      .permission = nfs_permission,
      .getattr    = nfs_getattr,
      .setattr    = nfs_setattr,
      .getxattr   = nfs4_getxattr,
      .setxattr   = nfs4_setxattr,
      .listxattr  = nfs4_listxattr,
};

struct nfs_rpc_ops      nfs_v4_clientops = {
      .version    = 4,              /* protocol version */
      .dentry_ops = &nfs4_dentry_operations,
      .dir_inode_ops    = &nfs4_dir_inode_operations,
      .file_inode_ops   = &nfs4_file_inode_operations,
      .getroot    = nfs4_proc_get_root,
      .getattr    = nfs4_proc_getattr,
      .setattr    = nfs4_proc_setattr,
      .lookup           = nfs4_proc_lookup,
      .access           = nfs4_proc_access,
      .readlink   = nfs4_proc_readlink,
      .read       = nfs4_proc_read,
      .write            = nfs4_proc_write,
      .commit           = nfs4_proc_commit,
      .create           = nfs4_proc_create,
      .remove           = nfs4_proc_remove,
      .unlink_setup     = nfs4_proc_unlink_setup,
      .unlink_done      = nfs4_proc_unlink_done,
      .rename           = nfs4_proc_rename,
      .link       = nfs4_proc_link,
      .symlink    = nfs4_proc_symlink,
      .mkdir            = nfs4_proc_mkdir,
      .rmdir            = nfs4_proc_remove,
      .readdir    = nfs4_proc_readdir,
      .mknod            = nfs4_proc_mknod,
      .statfs           = nfs4_proc_statfs,
      .fsinfo           = nfs4_proc_fsinfo,
      .pathconf   = nfs4_proc_pathconf,
      .decode_dirent    = nfs4_decode_dirent,
      .read_setup = nfs4_proc_read_setup,
      .read_done  = nfs4_read_done,
      .write_setup      = nfs4_proc_write_setup,
      .write_done = nfs4_write_done,
      .commit_setup     = nfs4_proc_commit_setup,
      .commit_done      = nfs4_commit_done,
      .file_open      = nfs_open,
      .file_release   = nfs_release,
      .lock       = nfs4_proc_lock,
      .clear_acl_cache = nfs4_zap_acl_attr,
};

/*
 * Local variables:
 *  c-basic-offset: 8
 * End:
 */

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