Logo Search packages:      
Sourcecode: linux version File versions  Download package

vfs.c

#define MSNFS     /* HACK HACK */
/*
 * linux/fs/nfsd/vfs.c
 *
 * File operations used by nfsd. Some of these have been ripped from
 * other parts of the kernel because they weren't exported, others
 * are partial duplicates with added or changed functionality.
 *
 * Note that several functions dget() the dentry upon which they want
 * to act, most notably those that create directory entries. Response
 * dentry's are dput()'d if necessary in the release callback.
 * So if you notice code paths that apparently fail to dput() the
 * dentry, don't worry--they have been taken care of.
 *
 * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de>
 * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp>
 */

#include <linux/string.h>
#include <linux/time.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/major.h>
#include <linux/splice.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
#include <linux/net.h>
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/in.h>
#include <linux/module.h>
#include <linux/namei.h>
#include <linux/vfs.h>
#include <linux/delay.h>
#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
#ifdef CONFIG_NFSD_V3
#include <linux/nfs3.h>
#include <linux/nfsd/xdr3.h>
#endif /* CONFIG_NFSD_V3 */
#include <linux/nfsd/nfsfh.h>
#include <linux/quotaops.h>
#include <linux/fsnotify.h>
#include <linux/posix_acl.h>
#include <linux/posix_acl_xattr.h>
#include <linux/xattr.h>
#ifdef CONFIG_NFSD_V4
#include <linux/nfs4.h>
#include <linux/nfs4_acl.h>
#include <linux/nfsd_idmap.h>
#include <linux/security.h>
#endif /* CONFIG_NFSD_V4 */
#include <linux/jhash.h>

#include <asm/uaccess.h>

#define NFSDDBG_FACILITY            NFSDDBG_FILEOP


/*
 * This is a cache of readahead params that help us choose the proper
 * readahead strategy. Initially, we set all readahead parameters to 0
 * and let the VFS handle things.
 * If you increase the number of cached files very much, you'll need to
 * add a hash table here.
 */
struct raparms {
      struct raparms          *p_next;
      unsigned int            p_count;
      ino_t             p_ino;
      dev_t             p_dev;
      int               p_set;
      struct file_ra_state    p_ra;
      unsigned int            p_hindex;
};

struct raparm_hbucket {
      struct raparms          *pb_head;
      spinlock_t        pb_lock;
} ____cacheline_aligned_in_smp;

static struct raparms *       raparml;
#define RAPARM_HASH_BITS      4
#define RAPARM_HASH_SIZE      (1<<RAPARM_HASH_BITS)
#define RAPARM_HASH_MASK      (RAPARM_HASH_SIZE-1)
static struct raparm_hbucket  raparm_hash[RAPARM_HASH_SIZE];

/* 
 * Called from nfsd_lookup and encode_dirent. Check if we have crossed 
 * a mount point.
 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
 *  or nfs_ok having possibly changed *dpp and *expp
 */
int
nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, 
                    struct svc_export **expp)
{
      struct svc_export *exp = *expp, *exp2 = NULL;
      struct dentry *dentry = *dpp;
      struct vfsmount *mnt = mntget(exp->ex_mnt);
      struct dentry *mounts = dget(dentry);
      int err = 0;

      while (follow_down(&mnt,&mounts)&&d_mountpoint(mounts));

      exp2 = rqst_exp_get_by_name(rqstp, mnt, mounts);
      if (IS_ERR(exp2)) {
            if (PTR_ERR(exp2) != -ENOENT)
                  err = PTR_ERR(exp2);
            dput(mounts);
            mntput(mnt);
            goto out;
      }
      if ((exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
            /* successfully crossed mount point */
            exp_put(exp);
            *expp = exp2;
            dput(dentry);
            *dpp = mounts;
      } else {
            exp_put(exp2);
            dput(mounts);
      }
      mntput(mnt);
out:
      return err;
}

__be32
nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
               const char *name, int len,
               struct svc_export **exp_ret, struct dentry **dentry_ret)
{
      struct svc_export *exp;
      struct dentry           *dparent;
      struct dentry           *dentry;
      __be32                  err;
      int               host_err;

      dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);

      /* Obtain dentry and export. */
      err = fh_verify(rqstp, fhp, S_IFDIR, MAY_EXEC);
      if (err)
            return err;

      dparent = fhp->fh_dentry;
      exp  = fhp->fh_export;
      exp_get(exp);

      /* Lookup the name, but don't follow links */
      if (isdotent(name, len)) {
            if (len==1)
                  dentry = dget(dparent);
            else if (dparent != exp->ex_dentry) {
                  dentry = dget_parent(dparent);
            } else  if (!EX_NOHIDE(exp))
                  dentry = dget(dparent); /* .. == . just like at / */
            else {
                  /* checking mountpoint crossing is very different when stepping up */
                  struct svc_export *exp2 = NULL;
                  struct dentry *dp;
                  struct vfsmount *mnt = mntget(exp->ex_mnt);
                  dentry = dget(dparent);
                  while(dentry == mnt->mnt_root && follow_up(&mnt, &dentry))
                        ;
                  dp = dget_parent(dentry);
                  dput(dentry);
                  dentry = dp;

                  exp2 = rqst_exp_parent(rqstp, mnt, dentry);
                  if (PTR_ERR(exp2) == -ENOENT) {
                        dput(dentry);
                        dentry = dget(dparent);
                  } else if (IS_ERR(exp2)) {
                        host_err = PTR_ERR(exp2);
                        dput(dentry);
                        mntput(mnt);
                        goto out_nfserr;
                  } else {
                        exp_put(exp);
                        exp = exp2;
                  }
                  mntput(mnt);
            }
      } else {
            fh_lock(fhp);
            dentry = lookup_one_len(name, dparent, len);
            host_err = PTR_ERR(dentry);
            if (IS_ERR(dentry))
                  goto out_nfserr;
            /*
             * check if we have crossed a mount point ...
             */
            if (d_mountpoint(dentry)) {
                  if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
                        dput(dentry);
                        goto out_nfserr;
                  }
            }
      }
      *dentry_ret = dentry;
      *exp_ret = exp;
      return 0;

out_nfserr:
      exp_put(exp);
      return nfserrno(host_err);
}

/*
 * Look up one component of a pathname.
 * N.B. After this call _both_ fhp and resfh need an fh_put
 *
 * If the lookup would cross a mountpoint, and the mounted filesystem
 * is exported to the client with NFSEXP_NOHIDE, then the lookup is
 * accepted as it stands and the mounted directory is
 * returned. Otherwise the covered directory is returned.
 * NOTE: this mountpoint crossing is not supported properly by all
 *   clients and is explicitly disallowed for NFSv3
 *      NeilBrown <neilb@cse.unsw.edu.au>
 */
__be32
nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
                              int len, struct svc_fh *resfh)
{
      struct svc_export *exp;
      struct dentry           *dentry;
      __be32 err;

      err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry);
      if (err)
            return err;
      err = check_nfsd_access(exp, rqstp);
      if (err)
            goto out;
      /*
       * Note: we compose the file handle now, but as the
       * dentry may be negative, it may need to be updated.
       */
      err = fh_compose(resfh, exp, dentry, fhp);
      if (!err && !dentry->d_inode)
            err = nfserr_noent;
out:
      dput(dentry);
      exp_put(exp);
      return err;
}


/*
 * Set various file attributes.
 * N.B. After this call fhp needs an fh_put
 */
__be32
nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
           int check_guard, time_t guardtime)
{
      struct dentry     *dentry;
      struct inode      *inode;
      int         accmode = MAY_SATTR;
      int         ftype = 0;
      int         imode;
      __be32            err;
      int         host_err;
      int         size_change = 0;

      if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))
            accmode |= MAY_WRITE|MAY_OWNER_OVERRIDE;
      if (iap->ia_valid & ATTR_SIZE)
            ftype = S_IFREG;

      /* Get inode */
      err = fh_verify(rqstp, fhp, ftype, accmode);
      if (err)
            goto out;

      dentry = fhp->fh_dentry;
      inode = dentry->d_inode;

      /* Ignore any mode updates on symlinks */
      if (S_ISLNK(inode->i_mode))
            iap->ia_valid &= ~ATTR_MODE;

      if (!iap->ia_valid)
            goto out;

      /*
       * NFSv2 does not differentiate between "set-[ac]time-to-now"
       * which only requires access, and "set-[ac]time-to-X" which
       * requires ownership.
       * So if it looks like it might be "set both to the same time which
       * is close to now", and if inode_change_ok fails, then we
       * convert to "set to now" instead of "set to explicit time"
       *
       * We only call inode_change_ok as the last test as technically
       * it is not an interface that we should be using.  It is only
       * valid if the filesystem does not define it's own i_op->setattr.
       */
#define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET)
#define     MAX_TOUCH_TIME_ERROR (30*60)
      if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET &&
          iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) {
            /*
             * Looks probable.
             *
             * Now just make sure time is in the right ballpark.
             * Solaris, at least, doesn't seem to care what the time
             * request is.  We require it be within 30 minutes of now.
             */
            time_t delta = iap->ia_atime.tv_sec - get_seconds();
            if (delta < 0)
                  delta = -delta;
            if (delta < MAX_TOUCH_TIME_ERROR &&
                inode_change_ok(inode, iap) != 0) {
                  /*
                   * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME.
                   * This will cause notify_change to set these times
                   * to "now"
                   */
                  iap->ia_valid &= ~BOTH_TIME_SET;
            }
      }
          
      /*
       * The size case is special.
       * It changes the file as well as the attributes.
       */
      if (iap->ia_valid & ATTR_SIZE) {
            if (iap->ia_size < inode->i_size) {
                  err = nfsd_permission(rqstp, fhp->fh_export, dentry, MAY_TRUNC|MAY_OWNER_OVERRIDE);
                  if (err)
                        goto out;
            }

            /*
             * If we are changing the size of the file, then
             * we need to break all leases.
             */
            host_err = break_lease(inode, FMODE_WRITE | O_NONBLOCK);
            if (host_err == -EWOULDBLOCK)
                  host_err = -ETIMEDOUT;
            if (host_err) /* ENOMEM or EWOULDBLOCK */
                  goto out_nfserr;

            host_err = get_write_access(inode);
            if (host_err)
                  goto out_nfserr;

            size_change = 1;
            host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
            if (host_err) {
                  put_write_access(inode);
                  goto out_nfserr;
            }
            DQUOT_INIT(inode);
      }

      imode = inode->i_mode;
      if (iap->ia_valid & ATTR_MODE) {
            iap->ia_mode &= S_IALLUGO;
            imode = iap->ia_mode |= (imode & ~S_IALLUGO);
            /* if changing uid/gid revoke setuid/setgid in mode */
            if ((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) {
                  iap->ia_valid |= ATTR_KILL_PRIV;
                  iap->ia_mode &= ~S_ISUID;
            }
            if ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid)
                  iap->ia_mode &= ~S_ISGID;
      } else {
            /*
             * Revoke setuid/setgid bit on chown/chgrp
             */
            if ((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid)
                  iap->ia_valid |= ATTR_KILL_SUID | ATTR_KILL_PRIV;
            if ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid)
                  iap->ia_valid |= ATTR_KILL_SGID;
      }

      /* Change the attributes. */

      iap->ia_valid |= ATTR_CTIME;

      err = nfserr_notsync;
      if (!check_guard || guardtime == inode->i_ctime.tv_sec) {
            fh_lock(fhp);
            host_err = notify_change(dentry, iap);
            err = nfserrno(host_err);
            fh_unlock(fhp);
      }
      if (size_change)
            put_write_access(inode);
      if (!err)
            if (EX_ISSYNC(fhp->fh_export))
                  write_inode_now(inode, 1);
out:
      return err;

out_nfserr:
      err = nfserrno(host_err);
      goto out;
}

#if defined(CONFIG_NFSD_V2_ACL) || \
    defined(CONFIG_NFSD_V3_ACL) || \
    defined(CONFIG_NFSD_V4)
static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf)
{
      ssize_t buflen;

      buflen = vfs_getxattr(dentry, key, NULL, 0);
      if (buflen <= 0)
            return buflen;

      *buf = kmalloc(buflen, GFP_KERNEL);
      if (!*buf)
            return -ENOMEM;

      return vfs_getxattr(dentry, key, *buf, buflen);
}
#endif

#if defined(CONFIG_NFSD_V4)
static int
set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key)
{
      int len;
      size_t buflen;
      char *buf = NULL;
      int error = 0;

      buflen = posix_acl_xattr_size(pacl->a_count);
      buf = kmalloc(buflen, GFP_KERNEL);
      error = -ENOMEM;
      if (buf == NULL)
            goto out;

      len = posix_acl_to_xattr(pacl, buf, buflen);
      if (len < 0) {
            error = len;
            goto out;
      }

      error = vfs_setxattr(dentry, key, buf, len, 0);
out:
      kfree(buf);
      return error;
}

__be32
nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
    struct nfs4_acl *acl)
{
      __be32 error;
      int host_error;
      struct dentry *dentry;
      struct inode *inode;
      struct posix_acl *pacl = NULL, *dpacl = NULL;
      unsigned int flags = 0;

      /* Get inode */
      error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, MAY_SATTR);
      if (error)
            return error;

      dentry = fhp->fh_dentry;
      inode = dentry->d_inode;
      if (S_ISDIR(inode->i_mode))
            flags = NFS4_ACL_DIR;

      host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags);
      if (host_error == -EINVAL) {
            return nfserr_attrnotsupp;
      } else if (host_error < 0)
            goto out_nfserr;

      host_error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS);
      if (host_error < 0)
            goto out_release;

      if (S_ISDIR(inode->i_mode))
            host_error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT);

out_release:
      posix_acl_release(pacl);
      posix_acl_release(dpacl);
out_nfserr:
      if (host_error == -EOPNOTSUPP)
            return nfserr_attrnotsupp;
      else
            return nfserrno(host_error);
}

static struct posix_acl *
_get_posix_acl(struct dentry *dentry, char *key)
{
      void *buf = NULL;
      struct posix_acl *pacl = NULL;
      int buflen;

      buflen = nfsd_getxattr(dentry, key, &buf);
      if (!buflen)
            buflen = -ENODATA;
      if (buflen <= 0)
            return ERR_PTR(buflen);

      pacl = posix_acl_from_xattr(buf, buflen);
      kfree(buf);
      return pacl;
}

int
nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl)
{
      struct inode *inode = dentry->d_inode;
      int error = 0;
      struct posix_acl *pacl = NULL, *dpacl = NULL;
      unsigned int flags = 0;

      pacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_ACCESS);
      if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA)
            pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
      if (IS_ERR(pacl)) {
            error = PTR_ERR(pacl);
            pacl = NULL;
            goto out;
      }

      if (S_ISDIR(inode->i_mode)) {
            dpacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_DEFAULT);
            if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA)
                  dpacl = NULL;
            else if (IS_ERR(dpacl)) {
                  error = PTR_ERR(dpacl);
                  dpacl = NULL;
                  goto out;
            }
            flags = NFS4_ACL_DIR;
      }

      *acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags);
      if (IS_ERR(*acl)) {
            error = PTR_ERR(*acl);
            *acl = NULL;
      }
 out:
      posix_acl_release(pacl);
      posix_acl_release(dpacl);
      return error;
}

#endif /* defined(CONFIG_NFS_V4) */

#ifdef CONFIG_NFSD_V3
/*
 * Check server access rights to a file system object
 */
struct accessmap {
      u32         access;
      int         how;
};
static struct accessmap nfs3_regaccess[] = {
    { NFS3_ACCESS_READ, MAY_READ                },
    { NFS3_ACCESS_EXECUTE,    MAY_EXEC                },
    { NFS3_ACCESS_MODIFY,     MAY_WRITE|MAY_TRUNC           },
    { NFS3_ACCESS_EXTEND,     MAY_WRITE               },

    { 0,                0                       }
};

static struct accessmap nfs3_diraccess[] = {
    { NFS3_ACCESS_READ, MAY_READ                },
    { NFS3_ACCESS_LOOKUP,     MAY_EXEC                },
    { NFS3_ACCESS_MODIFY,     MAY_EXEC|MAY_WRITE|MAY_TRUNC  },
    { NFS3_ACCESS_EXTEND,     MAY_EXEC|MAY_WRITE            },
    { NFS3_ACCESS_DELETE,     MAY_REMOVE              },

    { 0,                0                       }
};

static struct accessmap nfs3_anyaccess[] = {
      /* Some clients - Solaris 2.6 at least, make an access call
       * to the server to check for access for things like /dev/null
       * (which really, the server doesn't care about).  So
       * We provide simple access checking for them, looking
       * mainly at mode bits, and we make sure to ignore read-only
       * filesystem checks
       */
    { NFS3_ACCESS_READ, MAY_READ                },
    { NFS3_ACCESS_EXECUTE,    MAY_EXEC                },
    { NFS3_ACCESS_MODIFY,     MAY_WRITE|MAY_LOCAL_ACCESS    },
    { NFS3_ACCESS_EXTEND,     MAY_WRITE|MAY_LOCAL_ACCESS    },

    { 0,                0                       }
};

__be32
nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
{
      struct accessmap  *map;
      struct svc_export *export;
      struct dentry           *dentry;
      u32               query, result = 0, sresult = 0;
      __be32                  error;

      error = fh_verify(rqstp, fhp, 0, MAY_NOP);
      if (error)
            goto out;

      export = fhp->fh_export;
      dentry = fhp->fh_dentry;

      if (S_ISREG(dentry->d_inode->i_mode))
            map = nfs3_regaccess;
      else if (S_ISDIR(dentry->d_inode->i_mode))
            map = nfs3_diraccess;
      else
            map = nfs3_anyaccess;


      query = *access;
      for  (; map->access; map++) {
            if (map->access & query) {
                  __be32 err2;

                  sresult |= map->access;

                  err2 = nfsd_permission(rqstp, export, dentry, map->how);
                  switch (err2) {
                  case nfs_ok:
                        result |= map->access;
                        break;
                        
                  /* the following error codes just mean the access was not allowed,
                   * rather than an error occurred */
                  case nfserr_rofs:
                  case nfserr_acces:
                  case nfserr_perm:
                        /* simply don't "or" in the access bit. */
                        break;
                  default:
                        error = err2;
                        goto out;
                  }
            }
      }
      *access = result;
      if (supported)
            *supported = sresult;

 out:
      return error;
}
#endif /* CONFIG_NFSD_V3 */



/*
 * Open an existing file or directory.
 * The access argument indicates the type of open (read/write/lock)
 * N.B. After this call fhp needs an fh_put
 */
__be32
nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
                  int access, struct file **filp)
{
      struct dentry     *dentry;
      struct inode      *inode;
      int         flags = O_RDONLY|O_LARGEFILE;
      __be32            err;
      int         host_err;

      /*
       * If we get here, then the client has already done an "open",
       * and (hopefully) checked permission - so allow OWNER_OVERRIDE
       * in case a chmod has now revoked permission.
       */
      err = fh_verify(rqstp, fhp, type, access | MAY_OWNER_OVERRIDE);
      if (err)
            goto out;

      dentry = fhp->fh_dentry;
      inode = dentry->d_inode;

      /* Disallow write access to files with the append-only bit set
       * or any access when mandatory locking enabled
       */
      err = nfserr_perm;
      if (IS_APPEND(inode) && (access & MAY_WRITE))
            goto out;
      /*
       * We must ignore files (but only files) which might have mandatory
       * locks on them because there is no way to know if the accesser has
       * the lock.
       */
      if (S_ISREG((inode)->i_mode) && mandatory_lock(inode))
            goto out;

      if (!inode->i_fop)
            goto out;

      /*
       * Check to see if there are any leases on this file.
       * This may block while leases are broken.
       */
      host_err = break_lease(inode, O_NONBLOCK | ((access & MAY_WRITE) ? FMODE_WRITE : 0));
      if (host_err == -EWOULDBLOCK)
            host_err = -ETIMEDOUT;
      if (host_err) /* NOMEM or WOULDBLOCK */
            goto out_nfserr;

      if (access & MAY_WRITE) {
            if (access & MAY_READ)
                  flags = O_RDWR|O_LARGEFILE;
            else
                  flags = O_WRONLY|O_LARGEFILE;

            DQUOT_INIT(inode);
      }
      *filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_mnt), flags);
      if (IS_ERR(*filp))
            host_err = PTR_ERR(*filp);
out_nfserr:
      err = nfserrno(host_err);
out:
      return err;
}

/*
 * Close a file.
 */
void
nfsd_close(struct file *filp)
{
      fput(filp);
}

/*
 * Sync a file
 * As this calls fsync (not fdatasync) there is no need for a write_inode
 * after it.
 */
static inline int nfsd_dosync(struct file *filp, struct dentry *dp,
                        const struct file_operations *fop)
{
      struct inode *inode = dp->d_inode;
      int (*fsync) (struct file *, struct dentry *, int);
      int err;

      err = filemap_fdatawrite(inode->i_mapping);
      if (err == 0 && fop && (fsync = fop->fsync))
            err = fsync(filp, dp, 0);
      if (err == 0)
            err = filemap_fdatawait(inode->i_mapping);

      return err;
}
      

static int
nfsd_sync(struct file *filp)
{
        int err;
      struct inode *inode = filp->f_path.dentry->d_inode;
      dprintk("nfsd: sync file %s\n", filp->f_path.dentry->d_name.name);
      mutex_lock(&inode->i_mutex);
      err=nfsd_dosync(filp, filp->f_path.dentry, filp->f_op);
      mutex_unlock(&inode->i_mutex);

      return err;
}

int
nfsd_sync_dir(struct dentry *dp)
{
      return nfsd_dosync(NULL, dp, dp->d_inode->i_fop);
}

/*
 * Obtain the readahead parameters for the file
 * specified by (dev, ino).
 */

static inline struct raparms *
nfsd_get_raparms(dev_t dev, ino_t ino)
{
      struct raparms    *ra, **rap, **frap = NULL;
      int depth = 0;
      unsigned int hash;
      struct raparm_hbucket *rab;

      hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK;
      rab = &raparm_hash[hash];

      spin_lock(&rab->pb_lock);
      for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) {
            if (ra->p_ino == ino && ra->p_dev == dev)
                  goto found;
            depth++;
            if (ra->p_count == 0)
                  frap = rap;
      }
      depth = nfsdstats.ra_size*11/10;
      if (!frap) {      
            spin_unlock(&rab->pb_lock);
            return NULL;
      }
      rap = frap;
      ra = *frap;
      ra->p_dev = dev;
      ra->p_ino = ino;
      ra->p_set = 0;
      ra->p_hindex = hash;
found:
      if (rap != &rab->pb_head) {
            *rap = ra->p_next;
            ra->p_next   = rab->pb_head;
            rab->pb_head = ra;
      }
      ra->p_count++;
      nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++;
      spin_unlock(&rab->pb_lock);
      return ra;
}

/*
 * Grab and keep cached pages associated with a file in the svc_rqst
 * so that they can be passed to the network sendmsg/sendpage routines
 * directly. They will be released after the sending has completed.
 */
static int
nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
              struct splice_desc *sd)
{
      struct svc_rqst *rqstp = sd->u.data;
      struct page **pp = rqstp->rq_respages + rqstp->rq_resused;
      struct page *page = buf->page;
      size_t size;
      int ret;

      ret = buf->ops->confirm(pipe, buf);
      if (unlikely(ret))
            return ret;

      size = sd->len;

      if (rqstp->rq_res.page_len == 0) {
            get_page(page);
            put_page(*pp);
            *pp = page;
            rqstp->rq_resused++;
            rqstp->rq_res.page_base = buf->offset;
            rqstp->rq_res.page_len = size;
      } else if (page != pp[-1]) {
            get_page(page);
            if (*pp)
                  put_page(*pp);
            *pp = page;
            rqstp->rq_resused++;
            rqstp->rq_res.page_len += size;
      } else
            rqstp->rq_res.page_len += size;

      return size;
}

static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
                            struct splice_desc *sd)
{
      return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
}

static inline int svc_msnfs(struct svc_fh *ffhp)
{
#ifdef MSNFS
      return (ffhp->fh_export->ex_flags & NFSEXP_MSNFS);
#else
      return 0;
#endif
}

static __be32
nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
              loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
{
      struct inode *inode;
      struct raparms    *ra;
      mm_segment_t      oldfs;
      __be32            err;
      int         host_err;

      err = nfserr_perm;
      inode = file->f_path.dentry->d_inode;

      if (svc_msnfs(fhp) && !lock_may_read(inode, offset, *count))
            goto out;

      /* Get readahead parameters */
      ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino);

      if (ra && ra->p_set)
            file->f_ra = ra->p_ra;

      if (file->f_op->splice_read && rqstp->rq_splice_ok) {
            struct splice_desc sd = {
                  .len        = 0,
                  .total_len  = *count,
                  .pos        = offset,
                  .u.data           = rqstp,
            };

            rqstp->rq_resused = 1;
            host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
      } else {
            oldfs = get_fs();
            set_fs(KERNEL_DS);
            host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset);
            set_fs(oldfs);
      }

      /* Write back readahead params */
      if (ra) {
            struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex];
            spin_lock(&rab->pb_lock);
            ra->p_ra = file->f_ra;
            ra->p_set = 1;
            ra->p_count--;
            spin_unlock(&rab->pb_lock);
      }

      if (host_err >= 0) {
            nfsdstats.io_read += host_err;
            *count = host_err;
            err = 0;
            fsnotify_access(file->f_path.dentry);
      } else 
            err = nfserrno(host_err);
out:
      return err;
}

static void kill_suid(struct dentry *dentry)
{
      struct iattr      ia;
      ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;

      mutex_lock(&dentry->d_inode->i_mutex);
      notify_change(dentry, &ia);
      mutex_unlock(&dentry->d_inode->i_mutex);
}

static __be32
nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
                        loff_t offset, struct kvec *vec, int vlen,
                        unsigned long cnt, int *stablep)
{
      struct svc_export *exp;
      struct dentry           *dentry;
      struct inode            *inode;
      mm_segment_t            oldfs;
      __be32                  err = 0;
      int               host_err;
      int               stable = *stablep;

#ifdef MSNFS
      err = nfserr_perm;

      if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
            (!lock_may_write(file->f_path.dentry->d_inode, offset, cnt)))
            goto out;
#endif

      dentry = file->f_path.dentry;
      inode = dentry->d_inode;
      exp   = fhp->fh_export;

      /*
       * Request sync writes if
       *  - the sync export option has been set, or
       *  - the client requested O_SYNC behavior (NFSv3 feature).
       *  -   The file system doesn't support fsync().
       * When gathered writes have been configured for this volume,
       * flushing the data to disk is handled separately below.
       */

      if (file->f_op->fsync == 0) {/* COMMIT3 cannot work */
             stable = 2;
             *stablep = 2; /* FILE_SYNC */
      }

      if (!EX_ISSYNC(exp))
            stable = 0;
      if (stable && !EX_WGATHER(exp))
            file->f_flags |= O_SYNC;

      /* Write the data. */
      oldfs = get_fs(); set_fs(KERNEL_DS);
      host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset);
      set_fs(oldfs);
      if (host_err >= 0) {
            nfsdstats.io_write += cnt;
            fsnotify_modify(file->f_path.dentry);
      }

      /* clear setuid/setgid flag after write */
      if (host_err >= 0 && (inode->i_mode & (S_ISUID | S_ISGID)))
            kill_suid(dentry);

      if (host_err >= 0 && stable) {
            static ino_t      last_ino;
            static dev_t      last_dev;

            /*
             * Gathered writes: If another process is currently
             * writing to the file, there's a high chance
             * this is another nfsd (triggered by a bulk write
             * from a client's biod). Rather than syncing the
             * file with each write request, we sleep for 10 msec.
             *
             * I don't know if this roughly approximates
             * C. Juszak's idea of gathered writes, but it's a
             * nice and simple solution (IMHO), and it seems to
             * work:-)
             */
            if (EX_WGATHER(exp)) {
                  if (atomic_read(&inode->i_writecount) > 1
                      || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
                        dprintk("nfsd: write defer %d\n", task_pid_nr(current));
                        msleep(10);
                        dprintk("nfsd: write resume %d\n", task_pid_nr(current));
                  }

                  if (inode->i_state & I_DIRTY) {
                        dprintk("nfsd: write sync %d\n", task_pid_nr(current));
                        host_err=nfsd_sync(file);
                  }
#if 0
                  wake_up(&inode->i_wait);
#endif
            }
            last_ino = inode->i_ino;
            last_dev = inode->i_sb->s_dev;
      }

      dprintk("nfsd: write complete host_err=%d\n", host_err);
      if (host_err >= 0)
            err = 0;
      else 
            err = nfserrno(host_err);
out:
      return err;
}

/*
 * Read data from a file. count must contain the requested read count
 * on entry. On return, *count contains the number of bytes actually read.
 * N.B. After this call fhp needs an fh_put
 */
__be32
nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
            loff_t offset, struct kvec *vec, int vlen,
            unsigned long *count)
{
      __be32            err;

      if (file) {
            err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
                        MAY_READ|MAY_OWNER_OVERRIDE);
            if (err)
                  goto out;
            err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
      } else {
            err = nfsd_open(rqstp, fhp, S_IFREG, MAY_READ, &file);
            if (err)
                  goto out;
            err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
            nfsd_close(file);
      }
out:
      return err;
}

/*
 * Write data to a file.
 * The stable flag requests synchronous writes.
 * N.B. After this call fhp needs an fh_put
 */
__be32
nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
            loff_t offset, struct kvec *vec, int vlen, unsigned long cnt,
            int *stablep)
{
      __be32                  err = 0;

      if (file) {
            err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
                        MAY_WRITE|MAY_OWNER_OVERRIDE);
            if (err)
                  goto out;
            err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt,
                        stablep);
      } else {
            err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file);
            if (err)
                  goto out;

            if (cnt)
                  err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen,
                                   cnt, stablep);
            nfsd_close(file);
      }
out:
      return err;
}

#ifdef CONFIG_NFSD_V3
/*
 * Commit all pending writes to stable storage.
 * Strictly speaking, we could sync just the indicated file region here,
 * but there's currently no way we can ask the VFS to do so.
 *
 * Unfortunately we cannot lock the file to make sure we return full WCC
 * data to the client, as locking happens lower down in the filesystem.
 */
__be32
nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
               loff_t offset, unsigned long count)
{
      struct file *file;
      __be32            err;

      if ((u64)count > ~(u64)offset)
            return nfserr_inval;

      if ((err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file)) != 0)
            return err;
      if (EX_ISSYNC(fhp->fh_export)) {
            if (file->f_op && file->f_op->fsync) {
                  err = nfserrno(nfsd_sync(file));
            } else {
                  err = nfserr_notsupp;
            }
      }

      nfsd_close(file);
      return err;
}
#endif /* CONFIG_NFSD_V3 */

/*
 * Create a file (regular, directory, device, fifo); UNIX sockets 
 * not yet implemented.
 * If the response fh has been verified, the parent directory should
 * already be locked. Note that the parent directory is left locked.
 *
 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
 */
__be32
nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
            char *fname, int flen, struct iattr *iap,
            int type, dev_t rdev, struct svc_fh *resfhp)
{
      struct dentry     *dentry, *dchild = NULL;
      struct inode      *dirp;
      __be32            err;
      int         host_err;

      err = nfserr_perm;
      if (!flen)
            goto out;
      err = nfserr_exist;
      if (isdotent(fname, flen))
            goto out;

      err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE);
      if (err)
            goto out;

      dentry = fhp->fh_dentry;
      dirp = dentry->d_inode;

      err = nfserr_notdir;
      if(!dirp->i_op || !dirp->i_op->lookup)
            goto out;
      /*
       * Check whether the response file handle has been verified yet.
       * If it has, the parent directory should already be locked.
       */
      if (!resfhp->fh_dentry) {
            /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */
            fh_lock_nested(fhp, I_MUTEX_PARENT);
            dchild = lookup_one_len(fname, dentry, flen);
            host_err = PTR_ERR(dchild);
            if (IS_ERR(dchild))
                  goto out_nfserr;
            err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
            if (err)
                  goto out;
      } else {
            /* called from nfsd_proc_create */
            dchild = dget(resfhp->fh_dentry);
            if (!fhp->fh_locked) {
                  /* not actually possible */
                  printk(KERN_ERR
                        "nfsd_create: parent %s/%s not locked!\n",
                        dentry->d_parent->d_name.name,
                        dentry->d_name.name);
                  err = nfserr_io;
                  goto out;
            }
      }
      /*
       * Make sure the child dentry is still negative ...
       */
      err = nfserr_exist;
      if (dchild->d_inode) {
            dprintk("nfsd_create: dentry %s/%s not negative!\n",
                  dentry->d_name.name, dchild->d_name.name);
            goto out; 
      }

      if (!(iap->ia_valid & ATTR_MODE))
            iap->ia_mode = 0;
      iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;

      /*
       * Get the dir op function pointer.
       */
      err = 0;
      switch (type) {
      case S_IFREG:
            host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
            break;
      case S_IFDIR:
            host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
            break;
      case S_IFCHR:
      case S_IFBLK:
      case S_IFIFO:
      case S_IFSOCK:
            host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
            break;
      default:
              printk("nfsd: bad file type %o in nfsd_create\n", type);
            host_err = -EINVAL;
      }
      if (host_err < 0)
            goto out_nfserr;

      if (EX_ISSYNC(fhp->fh_export)) {
            err = nfserrno(nfsd_sync_dir(dentry));
            write_inode_now(dchild->d_inode, 1);
      }


      /* Set file attributes. Mode has already been set and
       * setting uid/gid works only for root. Irix appears to
       * send along the gid when it tries to implement setgid
       * directories via NFS.
       */
      if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID|ATTR_MODE)) != 0) {
            __be32 err2 = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
            if (err2)
                  err = err2;
      }
      /*
       * Update the file handle to get the new inode info.
       */
      if (!err)
            err = fh_update(resfhp);
out:
      if (dchild && !IS_ERR(dchild))
            dput(dchild);
      return err;

out_nfserr:
      err = nfserrno(host_err);
      goto out;
}

#ifdef CONFIG_NFSD_V3
/*
 * NFSv3 version of nfsd_create
 */
__be32
nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp,
            char *fname, int flen, struct iattr *iap,
            struct svc_fh *resfhp, int createmode, u32 *verifier,
              int *truncp, int *created)
{
      struct dentry     *dentry, *dchild = NULL;
      struct inode      *dirp;
      __be32            err;
      int         host_err;
      __u32       v_mtime=0, v_atime=0;

      err = nfserr_perm;
      if (!flen)
            goto out;
      err = nfserr_exist;
      if (isdotent(fname, flen))
            goto out;
      if (!(iap->ia_valid & ATTR_MODE))
            iap->ia_mode = 0;
      err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE);
      if (err)
            goto out;

      dentry = fhp->fh_dentry;
      dirp = dentry->d_inode;

      /* Get all the sanity checks out of the way before
       * we lock the parent. */
      err = nfserr_notdir;
      if(!dirp->i_op || !dirp->i_op->lookup)
            goto out;
      fh_lock_nested(fhp, I_MUTEX_PARENT);

      /*
       * Compose the response file handle.
       */
      dchild = lookup_one_len(fname, dentry, flen);
      host_err = PTR_ERR(dchild);
      if (IS_ERR(dchild))
            goto out_nfserr;

      err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
      if (err)
            goto out;

      if (createmode == NFS3_CREATE_EXCLUSIVE) {
            /* solaris7 gets confused (bugid 4218508) if these have
             * the high bit set, so just clear the high bits. If this is
             * ever changed to use different attrs for storing the
             * verifier, then do_open_lookup() will also need to be fixed
             * accordingly.
             */
            v_mtime = verifier[0]&0x7fffffff;
            v_atime = verifier[1]&0x7fffffff;
      }
      
      if (dchild->d_inode) {
            err = 0;

            switch (createmode) {
            case NFS3_CREATE_UNCHECKED:
                  if (! S_ISREG(dchild->d_inode->i_mode))
                        err = nfserr_exist;
                  else if (truncp) {
                        /* in nfsv4, we need to treat this case a little
                         * differently.  we don't want to truncate the
                         * file now; this would be wrong if the OPEN
                         * fails for some other reason.  furthermore,
                         * if the size is nonzero, we should ignore it
                         * according to spec!
                         */
                        *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
                  }
                  else {
                        iap->ia_valid &= ATTR_SIZE;
                        goto set_attr;
                  }
                  break;
            case NFS3_CREATE_EXCLUSIVE:
                  if (   dchild->d_inode->i_mtime.tv_sec == v_mtime
                      && dchild->d_inode->i_atime.tv_sec == v_atime
                      && dchild->d_inode->i_size  == 0 )
                        break;
                   /* fallthru */
            case NFS3_CREATE_GUARDED:
                  err = nfserr_exist;
            }
            goto out;
      }

      host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
      if (host_err < 0)
            goto out_nfserr;
      if (created)
            *created = 1;

      if (EX_ISSYNC(fhp->fh_export)) {
            err = nfserrno(nfsd_sync_dir(dentry));
            /* setattr will sync the child (or not) */
      }

      if (createmode == NFS3_CREATE_EXCLUSIVE) {
            /* Cram the verifier into atime/mtime */
            iap->ia_valid = ATTR_MTIME|ATTR_ATIME
                  | ATTR_MTIME_SET|ATTR_ATIME_SET;
            /* XXX someone who knows this better please fix it for nsec */ 
            iap->ia_mtime.tv_sec = v_mtime;
            iap->ia_atime.tv_sec = v_atime;
            iap->ia_mtime.tv_nsec = 0;
            iap->ia_atime.tv_nsec = 0;
      }

      /* Set file attributes.
       * Irix appears to send along the gid when it tries to
       * implement setgid directories via NFS. Clear out all that cruft.
       */
 set_attr:
      if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID|ATTR_MODE)) != 0) {
            __be32 err2 = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
            if (err2)
                  err = err2;
      }

      /*
       * Update the filehandle to get the new inode info.
       */
      if (!err)
            err = fh_update(resfhp);

 out:
      fh_unlock(fhp);
      if (dchild && !IS_ERR(dchild))
            dput(dchild);
      return err;
 
 out_nfserr:
      err = nfserrno(host_err);
      goto out;
}
#endif /* CONFIG_NFSD_V3 */

/*
 * Read a symlink. On entry, *lenp must contain the maximum path length that
 * fits into the buffer. On return, it contains the true length.
 * N.B. After this call fhp needs an fh_put
 */
__be32
nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
{
      struct dentry     *dentry;
      struct inode      *inode;
      mm_segment_t      oldfs;
      __be32            err;
      int         host_err;

      err = fh_verify(rqstp, fhp, S_IFLNK, MAY_NOP);
      if (err)
            goto out;

      dentry = fhp->fh_dentry;
      inode = dentry->d_inode;

      err = nfserr_inval;
      if (!inode->i_op || !inode->i_op->readlink)
            goto out;

      touch_atime(fhp->fh_export->ex_mnt, dentry);
      /* N.B. Why does this call need a get_fs()??
       * Remove the set_fs and watch the fireworks:-) --okir
       */

      oldfs = get_fs(); set_fs(KERNEL_DS);
      host_err = inode->i_op->readlink(dentry, buf, *lenp);
      set_fs(oldfs);

      if (host_err < 0)
            goto out_nfserr;
      *lenp = host_err;
      err = 0;
out:
      return err;

out_nfserr:
      err = nfserrno(host_err);
      goto out;
}

/*
 * Create a symlink and look up its inode
 * N.B. After this call _both_ fhp and resfhp need an fh_put
 */
__be32
nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
                        char *fname, int flen,
                        char *path,  int plen,
                        struct svc_fh *resfhp,
                        struct iattr *iap)
{
      struct dentry     *dentry, *dnew;
      __be32            err, cerr;
      int         host_err;
      umode_t           mode;

      err = nfserr_noent;
      if (!flen || !plen)
            goto out;
      err = nfserr_exist;
      if (isdotent(fname, flen))
            goto out;

      err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE);
      if (err)
            goto out;
      fh_lock(fhp);
      dentry = fhp->fh_dentry;
      dnew = lookup_one_len(fname, dentry, flen);
      host_err = PTR_ERR(dnew);
      if (IS_ERR(dnew))
            goto out_nfserr;

      mode = S_IALLUGO;
      /* Only the MODE ATTRibute is even vaguely meaningful */
      if (iap && (iap->ia_valid & ATTR_MODE))
            mode = iap->ia_mode & S_IALLUGO;

      if (unlikely(path[plen] != 0)) {
            char *path_alloced = kmalloc(plen+1, GFP_KERNEL);
            if (path_alloced == NULL)
                  host_err = -ENOMEM;
            else {
                  strncpy(path_alloced, path, plen);
                  path_alloced[plen] = 0;
                  host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced, mode);
                  kfree(path_alloced);
            }
      } else
            host_err = vfs_symlink(dentry->d_inode, dnew, path, mode);

      if (!host_err) {
            if (EX_ISSYNC(fhp->fh_export))
                  host_err = nfsd_sync_dir(dentry);
      }
      err = nfserrno(host_err);
      fh_unlock(fhp);

      cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
      dput(dnew);
      if (err==0) err = cerr;
out:
      return err;

out_nfserr:
      err = nfserrno(host_err);
      goto out;
}

/*
 * Create a hardlink
 * N.B. After this call _both_ ffhp and tfhp need an fh_put
 */
__be32
nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
                        char *name, int len, struct svc_fh *tfhp)
{
      struct dentry     *ddir, *dnew, *dold;
      struct inode      *dirp, *dest;
      __be32            err;
      int         host_err;

      err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_CREATE);
      if (err)
            goto out;
      err = fh_verify(rqstp, tfhp, -S_IFDIR, MAY_NOP);
      if (err)
            goto out;

      err = nfserr_perm;
      if (!len)
            goto out;
      err = nfserr_exist;
      if (isdotent(name, len))
            goto out;

      fh_lock_nested(ffhp, I_MUTEX_PARENT);
      ddir = ffhp->fh_dentry;
      dirp = ddir->d_inode;

      dnew = lookup_one_len(name, ddir, len);
      host_err = PTR_ERR(dnew);
      if (IS_ERR(dnew))
            goto out_nfserr;

      dold = tfhp->fh_dentry;
      dest = dold->d_inode;

      host_err = vfs_link(dold, dirp, dnew);
      if (!host_err) {
            if (EX_ISSYNC(ffhp->fh_export)) {
                  err = nfserrno(nfsd_sync_dir(ddir));
                  write_inode_now(dest, 1);
            }
            err = 0;
      } else {
            if (host_err == -EXDEV && rqstp->rq_vers == 2)
                  err = nfserr_acces;
            else
                  err = nfserrno(host_err);
      }

      dput(dnew);
out_unlock:
      fh_unlock(ffhp);
out:
      return err;

out_nfserr:
      err = nfserrno(host_err);
      goto out_unlock;
}

/*
 * Rename a file
 * N.B. After this call _both_ ffhp and tfhp need an fh_put
 */
__be32
nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
                      struct svc_fh *tfhp, char *tname, int tlen)
{
      struct dentry     *fdentry, *tdentry, *odentry, *ndentry, *trap;
      struct inode      *fdir, *tdir;
      __be32            err;
      int         host_err;

      err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_REMOVE);
      if (err)
            goto out;
      err = fh_verify(rqstp, tfhp, S_IFDIR, MAY_CREATE);
      if (err)
            goto out;

      fdentry = ffhp->fh_dentry;
      fdir = fdentry->d_inode;

      tdentry = tfhp->fh_dentry;
      tdir = tdentry->d_inode;

      err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
      if (ffhp->fh_export != tfhp->fh_export)
            goto out;

      err = nfserr_perm;
      if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
            goto out;

      /* cannot use fh_lock as we need deadlock protective ordering
       * so do it by hand */
      trap = lock_rename(tdentry, fdentry);
      ffhp->fh_locked = tfhp->fh_locked = 1;
      fill_pre_wcc(ffhp);
      fill_pre_wcc(tfhp);

      odentry = lookup_one_len(fname, fdentry, flen);
      host_err = PTR_ERR(odentry);
      if (IS_ERR(odentry))
            goto out_nfserr;

      host_err = -ENOENT;
      if (!odentry->d_inode)
            goto out_dput_old;
      host_err = -EINVAL;
      if (odentry == trap)
            goto out_dput_old;

      ndentry = lookup_one_len(tname, tdentry, tlen);
      host_err = PTR_ERR(ndentry);
      if (IS_ERR(ndentry))
            goto out_dput_old;
      host_err = -ENOTEMPTY;
      if (ndentry == trap)
            goto out_dput_new;

#ifdef MSNFS
      if ((ffhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
            ((atomic_read(&odentry->d_count) > 1)
             || (atomic_read(&ndentry->d_count) > 1))) {
                  host_err = -EPERM;
      } else
#endif
      host_err = vfs_rename(fdir, odentry, tdir, ndentry);
      if (!host_err && EX_ISSYNC(tfhp->fh_export)) {
            host_err = nfsd_sync_dir(tdentry);
            if (!host_err)
                  host_err = nfsd_sync_dir(fdentry);
      }

 out_dput_new:
      dput(ndentry);
 out_dput_old:
      dput(odentry);
 out_nfserr:
      err = nfserrno(host_err);

      /* we cannot reply on fh_unlock on the two filehandles,
       * as that would do the wrong thing if the two directories
       * were the same, so again we do it by hand
       */
      fill_post_wcc(ffhp);
      fill_post_wcc(tfhp);
      unlock_rename(tdentry, fdentry);
      ffhp->fh_locked = tfhp->fh_locked = 0;

out:
      return err;
}

/*
 * Unlink a file or directory
 * N.B. After this call fhp needs an fh_put
 */
__be32
nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
                        char *fname, int flen)
{
      struct dentry     *dentry, *rdentry;
      struct inode      *dirp;
      __be32            err;
      int         host_err;

      err = nfserr_acces;
      if (!flen || isdotent(fname, flen))
            goto out;
      err = fh_verify(rqstp, fhp, S_IFDIR, MAY_REMOVE);
      if (err)
            goto out;

      fh_lock_nested(fhp, I_MUTEX_PARENT);
      dentry = fhp->fh_dentry;
      dirp = dentry->d_inode;

      rdentry = lookup_one_len(fname, dentry, flen);
      host_err = PTR_ERR(rdentry);
      if (IS_ERR(rdentry))
            goto out_nfserr;

      if (!rdentry->d_inode) {
            dput(rdentry);
            err = nfserr_noent;
            goto out;
      }

      if (!type)
            type = rdentry->d_inode->i_mode & S_IFMT;

      if (type != S_IFDIR) { /* It's UNLINK */
#ifdef MSNFS
            if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
                  (atomic_read(&rdentry->d_count) > 1)) {
                  host_err = -EPERM;
            } else
#endif
            host_err = vfs_unlink(dirp, rdentry);
      } else { /* It's RMDIR */
            host_err = vfs_rmdir(dirp, rdentry);
      }

      dput(rdentry);

      if (host_err)
            goto out_nfserr;
      if (EX_ISSYNC(fhp->fh_export))
            host_err = nfsd_sync_dir(dentry);

out_nfserr:
      err = nfserrno(host_err);
out:
      return err;
}

/*
 * Read entries from a directory.
 * The  NFSv3/4 verifier we ignore for now.
 */
__be32
nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 
           struct readdir_cd *cdp, filldir_t func)
{
      __be32            err;
      int         host_err;
      struct file *file;
      loff_t            offset = *offsetp;

      err = nfsd_open(rqstp, fhp, S_IFDIR, MAY_READ, &file);
      if (err)
            goto out;

      offset = vfs_llseek(file, offset, 0);
      if (offset < 0) {
            err = nfserrno((int)offset);
            goto out_close;
      }

      /*
       * Read the directory entries. This silly loop is necessary because
       * readdir() is not guaranteed to fill up the entire buffer, but
       * may choose to do less.
       */

      do {
            cdp->err = nfserr_eof; /* will be cleared on successful read */
            host_err = vfs_readdir(file, func, cdp);
      } while (host_err >=0 && cdp->err == nfs_ok);
      if (host_err)
            err = nfserrno(host_err);
      else
            err = cdp->err;
      *offsetp = vfs_llseek(file, 0, 1);

      if (err == nfserr_eof || err == nfserr_toosmall)
            err = nfs_ok; /* can still be found in ->err */
out_close:
      nfsd_close(file);
out:
      return err;
}

/*
 * Get file system stats
 * N.B. After this call fhp needs an fh_put
 */
__be32
nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat)
{
      __be32 err = fh_verify(rqstp, fhp, 0, MAY_NOP);
      if (!err && vfs_statfs(fhp->fh_dentry,stat))
            err = nfserr_io;
      return err;
}

static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
{
      return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
}

/*
 * Check for a user's access permissions to this inode.
 */
__be32
nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
                              struct dentry *dentry, int acc)
{
      struct inode      *inode = dentry->d_inode;
      int         err;

      if (acc == MAY_NOP)
            return 0;
#if 0
      dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
            acc,
            (acc & MAY_READ)? " read"  : "",
            (acc & MAY_WRITE)?      " write" : "",
            (acc & MAY_EXEC)? " exec"  : "",
            (acc & MAY_SATTR)?      " sattr" : "",
            (acc & MAY_TRUNC)?      " trunc" : "",
            (acc & MAY_LOCK)? " lock"  : "",
            (acc & MAY_OWNER_OVERRIDE)? " owneroverride" : "",
            inode->i_mode,
            IS_IMMUTABLE(inode)?    " immut" : "",
            IS_APPEND(inode)? " append" : "",
            IS_RDONLY(inode)? " ro" : "");
      dprintk("      owner %d/%d user %d/%d\n",
            inode->i_uid, inode->i_gid, current->fsuid, current->fsgid);
#endif

      /* Normally we reject any write/sattr etc access on a read-only file
       * system.  But if it is IRIX doing check on write-access for a 
       * device special file, we ignore rofs.
       */
      if (!(acc & MAY_LOCAL_ACCESS))
            if (acc & (MAY_WRITE | MAY_SATTR | MAY_TRUNC)) {
                  if (exp_rdonly(rqstp, exp) || IS_RDONLY(inode))
                        return nfserr_rofs;
                  if (/* (acc & MAY_WRITE) && */ IS_IMMUTABLE(inode))
                        return nfserr_perm;
            }
      if ((acc & MAY_TRUNC) && IS_APPEND(inode))
            return nfserr_perm;

      if (acc & MAY_LOCK) {
            /* If we cannot rely on authentication in NLM requests,
             * just allow locks, otherwise require read permission, or
             * ownership
             */
            if (exp->ex_flags & NFSEXP_NOAUTHNLM)
                  return 0;
            else
                  acc = MAY_READ | MAY_OWNER_OVERRIDE;
      }
      /*
       * The file owner always gets access permission for accesses that
       * would normally be checked at open time. This is to make
       * file access work even when the client has done a fchmod(fd, 0).
       *
       * However, `cp foo bar' should fail nevertheless when bar is
       * readonly. A sensible way to do this might be to reject all
       * attempts to truncate a read-only file, because a creat() call
       * always implies file truncation.
       * ... but this isn't really fair.  A process may reasonably call
       * ftruncate on an open file descriptor on a file with perm 000.
       * We must trust the client to do permission checking - using "ACCESS"
       * with NFSv3.
       */
      if ((acc & MAY_OWNER_OVERRIDE) &&
          inode->i_uid == current->fsuid)
            return 0;

      err = permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC), NULL);

      /* Allow read access to binaries even when mode 111 */
      if (err == -EACCES && S_ISREG(inode->i_mode) &&
          acc == (MAY_READ | MAY_OWNER_OVERRIDE))
            err = permission(inode, MAY_EXEC, NULL);

      return err? nfserrno(err) : 0;
}

void
nfsd_racache_shutdown(void)
{
      if (!raparml)
            return;
      dprintk("nfsd: freeing readahead buffers.\n");
      kfree(raparml);
      raparml = NULL;
}
/*
 * Initialize readahead param cache
 */
int
nfsd_racache_init(int cache_size)
{
      int   i;
      int   j = 0;
      int   nperbucket;


      if (raparml)
            return 0;
      if (cache_size < 2*RAPARM_HASH_SIZE)
            cache_size = 2*RAPARM_HASH_SIZE;
      raparml = kcalloc(cache_size, sizeof(struct raparms), GFP_KERNEL);

      if (!raparml) {
            printk(KERN_WARNING
                  "nfsd: Could not allocate memory read-ahead cache.\n");
            return -ENOMEM;
      }

      dprintk("nfsd: allocating %d readahead buffers.\n", cache_size);
      for (i = 0 ; i < RAPARM_HASH_SIZE ; i++) {
            raparm_hash[i].pb_head = NULL;
            spin_lock_init(&raparm_hash[i].pb_lock);
      }
      nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE);
      for (i = 0; i < cache_size - 1; i++) {
            if (i % nperbucket == 0)
                  raparm_hash[j++].pb_head = raparml + i;
            if (i % nperbucket < nperbucket-1)
                  raparml[i].p_next = raparml + i + 1;
      }

      nfsdstats.ra_size = cache_size;
      return 0;
}

#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
struct posix_acl *
nfsd_get_posix_acl(struct svc_fh *fhp, int type)
{
      struct inode *inode = fhp->fh_dentry->d_inode;
      char *name;
      void *value = NULL;
      ssize_t size;
      struct posix_acl *acl;

      if (!IS_POSIXACL(inode))
            return ERR_PTR(-EOPNOTSUPP);

      switch (type) {
      case ACL_TYPE_ACCESS:
            name = POSIX_ACL_XATTR_ACCESS;
            break;
      case ACL_TYPE_DEFAULT:
            name = POSIX_ACL_XATTR_DEFAULT;
            break;
      default:
            return ERR_PTR(-EOPNOTSUPP);
      }

      size = nfsd_getxattr(fhp->fh_dentry, name, &value);
      if (size < 0)
            return ERR_PTR(size);

      acl = posix_acl_from_xattr(value, size);
      kfree(value);
      return acl;
}

int
nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl)
{
      struct inode *inode = fhp->fh_dentry->d_inode;
      char *name;
      void *value = NULL;
      size_t size;
      int error;

      if (!IS_POSIXACL(inode) || !inode->i_op ||
          !inode->i_op->setxattr || !inode->i_op->removexattr)
            return -EOPNOTSUPP;
      switch(type) {
            case ACL_TYPE_ACCESS:
                  name = POSIX_ACL_XATTR_ACCESS;
                  break;
            case ACL_TYPE_DEFAULT:
                  name = POSIX_ACL_XATTR_DEFAULT;
                  break;
            default:
                  return -EOPNOTSUPP;
      }

      if (acl && acl->a_count) {
            size = posix_acl_xattr_size(acl->a_count);
            value = kmalloc(size, GFP_KERNEL);
            if (!value)
                  return -ENOMEM;
            error = posix_acl_to_xattr(acl, value, size);
            if (error < 0)
                  goto getout;
            size = error;
      } else
            size = 0;

      if (size)
            error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0);
      else {
            if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT)
                  error = 0;
            else {
                  error = vfs_removexattr(fhp->fh_dentry, name);
                  if (error == -ENODATA)
                        error = 0;
            }
      }

getout:
      kfree(value);
      return error;
}
#endif  /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */

Generated by  Doxygen 1.6.0   Back to index