[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit

Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/fs/nfsd/vfs.c b/ap/os/linux/linux-3.4.x/fs/nfsd/vfs.c
new file mode 100644
index 0000000..36620e6
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/nfsd/vfs.c
@@ -0,0 +1,2362 @@
+/*
+ * 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/fs.h>
+#include <linux/file.h>
+#include <linux/splice.h>
+#include <linux/fcntl.h>
+#include <linux/namei.h>
+#include <linux/delay.h>
+#include <linux/fsnotify.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/xattr.h>
+#include <linux/jhash.h>
+#include <linux/ima.h>
+#include <linux/slab.h>
+#include <asm/uaccess.h>
+#include <linux/exportfs.h>
+#include <linux/writeback.h>
+
+#ifdef CONFIG_NFSD_V3
+#include "xdr3.h"
+#endif /* CONFIG_NFSD_V3 */
+
+#ifdef CONFIG_NFSD_V4
+#include "acl.h"
+#include "idmap.h"
+#endif /* CONFIG_NFSD_V4 */
+
+#include "nfsd.h"
+#include "vfs.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;
+
+#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 path path = {.mnt = mntget(exp->ex_path.mnt),
+			    .dentry = dget(dentry)};
+	int err = 0;
+
+	err = follow_down(&path);
+	if (err < 0)
+		goto out;
+
+	exp2 = rqst_exp_get_by_name(rqstp, &path);
+	if (IS_ERR(exp2)) {
+		err = PTR_ERR(exp2);
+		/*
+		 * We normally allow NFS clients to continue
+		 * "underneath" a mountpoint that is not exported.
+		 * The exception is V4ROOT, where no traversal is ever
+		 * allowed without an explicit export of the new
+		 * directory.
+		 */
+		if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT))
+			err = 0;
+		path_put(&path);
+		goto out;
+	}
+	if (nfsd_v4client(rqstp) ||
+		(exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
+		/* successfully crossed mount point */
+		/*
+		 * This is subtle: path.dentry is *not* on path.mnt
+		 * at this point.  The only reason we are safe is that
+		 * original mnt is pinned down by exp, so we should
+		 * put path *before* putting exp
+		 */
+		*dpp = path.dentry;
+		path.dentry = dentry;
+		*expp = exp2;
+		exp2 = exp;
+	}
+	path_put(&path);
+	exp_put(exp2);
+out:
+	return err;
+}
+
+static void follow_to_parent(struct path *path)
+{
+	struct dentry *dp;
+
+	while (path->dentry == path->mnt->mnt_root && follow_up(path))
+		;
+	dp = dget_parent(path->dentry);
+	dput(path->dentry);
+	path->dentry = dp;
+}
+
+static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp)
+{
+	struct svc_export *exp2;
+	struct path path = {.mnt = mntget((*exp)->ex_path.mnt),
+			    .dentry = dget(dparent)};
+
+	follow_to_parent(&path);
+
+	exp2 = rqst_exp_parent(rqstp, &path);
+	if (PTR_ERR(exp2) == -ENOENT) {
+		*dentryp = dget(dparent);
+	} else if (IS_ERR(exp2)) {
+		path_put(&path);
+		return PTR_ERR(exp2);
+	} else {
+		*dentryp = dget(path.dentry);
+		exp_put(*exp);
+		*exp = exp2;
+	}
+	path_put(&path);
+	return 0;
+}
+
+/*
+ * For nfsd purposes, we treat V4ROOT exports as though there was an
+ * export at *every* directory.
+ */
+int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp)
+{
+	if (d_mountpoint(dentry))
+		return 1;
+	if (nfsd4_is_junction(dentry))
+		return 1;
+	if (!(exp->ex_flags & NFSEXP_V4ROOT))
+		return 0;
+	return dentry->d_inode != NULL;
+}
+
+__be32
+nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		   const char *name, unsigned int len,
+		   struct svc_export **exp_ret, struct dentry **dentry_ret)
+{
+	struct svc_export	*exp;
+	struct dentry		*dparent;
+	struct dentry		*dentry;
+	int			host_err;
+
+	dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
+
+	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_path.dentry)
+			dentry = dget_parent(dparent);
+		else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp))
+			dentry = dget(dparent); /* .. == . just like at / */
+		else {
+			/* checking mountpoint crossing is very different when stepping up */
+			host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry);
+			if (host_err)
+				goto out_nfserr;
+		}
+	} 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 (nfsd_mountpoint(dentry, exp)) {
+			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,
+				unsigned int len, struct svc_fh *resfh)
+{
+	struct svc_export	*exp;
+	struct dentry		*dentry;
+	__be32 err;
+
+	err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
+	if (err)
+		return 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;
+}
+
+static int nfsd_break_lease(struct inode *inode)
+{
+	if (!S_ISREG(inode->i_mode))
+		return 0;
+	return break_lease(inode, O_WRONLY | O_NONBLOCK);
+}
+
+/*
+ * Commit metadata changes to stable storage.
+ */
+static int
+commit_metadata(struct svc_fh *fhp)
+{
+	struct inode *inode = fhp->fh_dentry->d_inode;
+	const struct export_operations *export_ops = inode->i_sb->s_export_op;
+
+	if (!EX_ISSYNC(fhp->fh_export))
+		return 0;
+
+	if (export_ops->commit_metadata)
+		return export_ops->commit_metadata(inode);
+	return sync_inode_metadata(inode, 1);
+}
+
+/*
+ * Go over the attributes and take care of the small differences between
+ * NFS semantics and what Linux expects.
+ */
+static void
+nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap)
+{
+	/*
+	 * 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.
+	 */
+#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;
+		}
+	}
+
+	/* sanitize the mode change */
+	if (iap->ia_valid & ATTR_MODE) {
+		iap->ia_mode &= S_IALLUGO;
+		iap->ia_mode |= (inode->i_mode & ~S_IALLUGO);
+	}
+
+	/* Revoke setuid/setgid on chown */
+	if (!S_ISDIR(inode->i_mode) &&
+	    (((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) ||
+	     ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid))) {
+		iap->ia_valid |= ATTR_KILL_PRIV;
+		if (iap->ia_valid & ATTR_MODE) {
+			/* we're setting mode too, just clear the s*id bits */
+			iap->ia_mode &= ~S_ISUID;
+			if (iap->ia_mode & S_IXGRP)
+				iap->ia_mode &= ~S_ISGID;
+		} else {
+			/* set ATTR_KILL_* bits and let VFS handle it */
+			iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID);
+		}
+	}
+}
+
+static __be32
+nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		struct iattr *iap)
+{
+	struct inode *inode = fhp->fh_dentry->d_inode;
+	int host_err;
+
+	if (iap->ia_size < inode->i_size) {
+		__be32 err;
+
+		err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
+				NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE);
+		if (err)
+			return err;
+	}
+
+	host_err = get_write_access(inode);
+	if (host_err)
+		goto out_nfserrno;
+
+	host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
+	if (host_err)
+		goto out_put_write_access;
+	return 0;
+
+out_put_write_access:
+	put_write_access(inode);
+out_nfserrno:
+	return nfserrno(host_err);
+}
+
+/*
+ * Set various file attributes.  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 = NFSD_MAY_SATTR;
+	umode_t		ftype = 0;
+	__be32		err;
+	int		host_err;
+	bool		get_write_count;
+	int		size_change = 0;
+
+	if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))
+		accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
+	if (iap->ia_valid & ATTR_SIZE)
+		ftype = S_IFREG;
+
+	/* Callers that do fh_verify should do the fh_want_write: */
+	get_write_count = !fhp->fh_dentry;
+
+	/* Get inode */
+	err = fh_verify(rqstp, fhp, ftype, accmode);
+	if (err)
+		goto out;
+	if (get_write_count) {
+		host_err = fh_want_write(fhp);
+		if (host_err)
+			return nfserrno(host_err);
+	}
+
+	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;
+
+	nfsd_sanitize_attrs(inode, iap);
+
+	/*
+	 * The size case is special, it changes the file in addition to the
+	 * attributes.
+	 */
+	if (iap->ia_valid & ATTR_SIZE) {
+		err = nfsd_get_write_access(rqstp, fhp, iap);
+		if (err)
+			goto out;
+		size_change = 1;
+	}
+
+	iap->ia_valid |= ATTR_CTIME;
+
+	if (check_guard && guardtime != inode->i_ctime.tv_sec) {
+		err = nfserr_notsync;
+		goto out_put_write_access;
+	}
+
+	host_err = nfsd_break_lease(inode);
+	if (host_err)
+		goto out_put_write_access_nfserror;
+
+	fh_lock(fhp);
+	host_err = notify_change(dentry, iap);
+	fh_unlock(fhp);
+
+out_put_write_access_nfserror:
+	err = nfserrno(host_err);
+out_put_write_access:
+	if (size_change)
+		put_write_access(inode);
+	if (!err)
+		commit_metadata(fhp);
+out:
+	return err;
+}
+
+#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;
+	ssize_t ret;
+
+	buflen = vfs_getxattr(dentry, key, NULL, 0);
+	if (buflen <= 0)
+		return buflen;
+
+	*buf = kmalloc(buflen, GFP_KERNEL);
+	if (!*buf)
+		return -ENOMEM;
+
+	ret = vfs_getxattr(dentry, key, *buf, buflen);
+	if (ret < 0)
+		kfree(*buf);
+	return ret;
+}
+#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;
+
+	if (!pacl)
+		return vfs_setxattr(dentry, key, NULL, 0, 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, NFSD_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;
+}
+
+/*
+ * NFS junction information is stored in an extended attribute.
+ */
+#define NFSD_JUNCTION_XATTR_NAME	XATTR_TRUSTED_PREFIX "junction.nfs"
+
+/**
+ * nfsd4_is_junction - Test if an object could be an NFS junction
+ *
+ * @dentry: object to test
+ *
+ * Returns 1 if "dentry" appears to contain NFS junction information.
+ * Otherwise 0 is returned.
+ */
+int nfsd4_is_junction(struct dentry *dentry)
+{
+	struct inode *inode = dentry->d_inode;
+
+	if (inode == NULL)
+		return 0;
+	if (inode->i_mode & S_IXUGO)
+		return 0;
+	if (!(inode->i_mode & S_ISVTX))
+		return 0;
+	if (vfs_getxattr(dentry, NFSD_JUNCTION_XATTR_NAME, NULL, 0) <= 0)
+		return 0;
+	return 1;
+}
+#endif /* defined(CONFIG_NFSD_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,	NFSD_MAY_READ			},
+    {	NFS3_ACCESS_EXECUTE,	NFSD_MAY_EXEC			},
+    {	NFS3_ACCESS_MODIFY,	NFSD_MAY_WRITE|NFSD_MAY_TRUNC	},
+    {	NFS3_ACCESS_EXTEND,	NFSD_MAY_WRITE			},
+
+    {	0,			0				}
+};
+
+static struct accessmap	nfs3_diraccess[] = {
+    {	NFS3_ACCESS_READ,	NFSD_MAY_READ			},
+    {	NFS3_ACCESS_LOOKUP,	NFSD_MAY_EXEC			},
+    {	NFS3_ACCESS_MODIFY,	NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC},
+    {	NFS3_ACCESS_EXTEND,	NFSD_MAY_EXEC|NFSD_MAY_WRITE	},
+    {	NFS3_ACCESS_DELETE,	NFSD_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,	NFSD_MAY_READ			},
+    {	NFS3_ACCESS_EXECUTE,	NFSD_MAY_EXEC			},
+    {	NFS3_ACCESS_MODIFY,	NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS	},
+    {	NFS3_ACCESS_EXTEND,	NFSD_MAY_WRITE|NFSD_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, NFSD_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 */
+
+static int nfsd_open_break_lease(struct inode *inode, int access)
+{
+	unsigned int mode;
+
+	if (access & NFSD_MAY_NOT_BREAK_LEASE)
+		return 0;
+	mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY;
+	return break_lease(inode, mode | O_NONBLOCK);
+}
+
+/*
+ * Open an existing file or directory.
+ * The may_flags argument indicates the type of open (read/write/lock)
+ * and additional flags.
+ * N.B. After this call fhp needs an fh_put
+ */
+__be32
+nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
+			int may_flags, struct file **filp)
+{
+	struct dentry	*dentry;
+	struct inode	*inode;
+	int		flags = O_RDONLY|O_LARGEFILE;
+	__be32		err;
+	int		host_err = 0;
+
+	validate_process_creds();
+
+	/*
+	 * 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, may_flags | NFSD_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) && (may_flags & NFSD_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;
+
+	host_err = nfsd_open_break_lease(inode, may_flags);
+	if (host_err) /* NOMEM or WOULDBLOCK */
+		goto out_nfserr;
+
+	if (may_flags & NFSD_MAY_WRITE) {
+		if (may_flags & NFSD_MAY_READ)
+			flags = O_RDWR|O_LARGEFILE;
+		else
+			flags = O_WRONLY|O_LARGEFILE;
+	}
+	*filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_path.mnt),
+			    flags, current_cred());
+	if (IS_ERR(*filp)) {
+		host_err = PTR_ERR(*filp);
+		*filp = NULL;
+	} else {
+		host_err = ima_file_check(*filp, may_flags);
+
+		if (may_flags & NFSD_MAY_64BIT_COOKIE)
+			(*filp)->f_mode |= FMODE_64BITHASH;
+		else
+			(*filp)->f_mode |= FMODE_32BITHASH;
+	}
+
+out_nfserr:
+	err = nfserrno(host_err);
+out:
+	validate_process_creds();
+	return err;
+}
+
+/*
+ * Close a file.
+ */
+void
+nfsd_close(struct file *filp)
+{
+	fput(filp);
+}
+
+/*
+ * 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;
+	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;
+
+	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 __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)
+{
+	mm_segment_t	oldfs;
+	__be32		err;
+	int		host_err;
+
+	err = nfserr_perm;
+
+	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);
+	}
+
+	if (host_err >= 0) {
+		nfsdstats.io_read += host_err;
+		*count = host_err;
+		err = 0;
+		fsnotify_access(file);
+	} else 
+		err = nfserrno(host_err);
+	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);
+}
+
+/*
+ * 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:-)
+ *
+ * Note: we do this only in the NFSv2 case, since v3 and higher have a
+ * better tool (separate unstable writes and commits) for solving this
+ * problem.
+ */
+static int wait_for_concurrent_writes(struct file *file)
+{
+	struct inode *inode = file->f_path.dentry->d_inode;
+	static ino_t last_ino;
+	static dev_t last_dev;
+	int err = 0;
+
+	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));
+		err = vfs_fsync(file, 0);
+	}
+	last_ino = inode->i_ino;
+	last_dev = inode->i_sb->s_dev;
+	return err;
+}
+
+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;
+	int			use_wgather;
+
+	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 NFSv2 gathered writes have been configured for this volume,
+	 * flushing the data to disk is handled separately below.
+	 */
+	use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
+
+	if (!file->f_op->fsync) {/* COMMIT3 cannot work */
+	       stable = 2;
+	       *stablep = 2; /* FILE_SYNC */
+	}
+
+	if (!EX_ISSYNC(exp))
+		stable = 0;
+	if (stable && !use_wgather) {
+		spin_lock(&file->f_lock);
+		file->f_flags |= O_SYNC;
+		spin_unlock(&file->f_lock);
+	}
+
+	/* 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)
+		goto out_nfserr;
+	*cnt = host_err;
+	nfsdstats.io_write += host_err;
+	fsnotify_modify(file);
+
+	/* clear setuid/setgid flag after write */
+	if (inode->i_mode & (S_ISUID | S_ISGID))
+		kill_suid(dentry);
+
+	if (stable && use_wgather)
+		host_err = wait_for_concurrent_writes(file);
+
+out_nfserr:
+	dprintk("nfsd: write complete host_err=%d\n", host_err);
+	if (host_err >= 0)
+		err = 0;
+	else
+		err = nfserrno(host_err);
+	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,
+	loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
+{
+	struct file *file;
+	struct inode *inode;
+	struct raparms	*ra;
+	__be32 err;
+
+	err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file);
+	if (err)
+		return err;
+
+	inode = file->f_path.dentry->d_inode;
+
+	/* 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;
+
+	err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
+
+	/* 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);
+	}
+
+	nfsd_close(file);
+	return err;
+}
+
+/* As above, but use the provided file descriptor. */
+__be32
+nfsd_read_file(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,
+				NFSD_MAY_READ|NFSD_MAY_OWNER_OVERRIDE);
+		if (err)
+			goto out;
+		err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
+	} else /* Note file may still be NULL in NFSv4 special stateid case: */
+		err = nfsd_read(rqstp, fhp, offset, vec, vlen, count);
+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,
+				NFSD_MAY_WRITE|NFSD_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, NFSD_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.
+ *
+ * Note: we only guarantee that data that lies within the range specified
+ * by the 'offset' and 'count' parameters will be synced.
+ *
+ * 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;
+	loff_t		end = LLONG_MAX;
+	__be32		err = nfserr_inval;
+
+	if (offset < 0)
+		goto out;
+	if (count != 0) {
+		end = offset + (loff_t)count - 1;
+		if (end < offset)
+			goto out;
+	}
+
+	err = nfsd_open(rqstp, fhp, S_IFREG,
+			NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &file);
+	if (err)
+		goto out;
+	if (EX_ISSYNC(fhp->fh_export)) {
+		int err2 = vfs_fsync_range(file, offset, end, 0);
+
+		if (err2 != -EINVAL)
+			err = nfserrno(err2);
+		else
+			err = nfserr_notsupp;
+	}
+
+	nfsd_close(file);
+out:
+	return err;
+}
+#endif /* CONFIG_NFSD_V3 */
+
+static __be32
+nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
+			struct iattr *iap)
+{
+	/*
+	 * Mode has already been set earlier in create:
+	 */
+	iap->ia_valid &= ~ATTR_MODE;
+	/*
+	 * Setting uid/gid works only for root.  Irix appears to
+	 * send along the gid on create when it tries to implement
+	 * setgid directories via NFS:
+	 */
+	if (current_fsuid() != 0)
+		iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
+	if (iap->ia_valid)
+		return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
+	return 0;
+}
+
+/* HPUX client sometimes creates a file in mode 000, and sets size to 0.
+ * setting size to 0 may fail for some specific file systems by the permission
+ * checking which requires WRITE permission but the mode is 000.
+ * we ignore the resizing(to 0) on the just new created file, since the size is
+ * 0 after file created.
+ *
+ * call this only after vfs_create() is called.
+ * */
+static void
+nfsd_check_ignore_resizing(struct iattr *iap)
+{
+	if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
+		iap->ia_valid &= ~ATTR_SIZE;
+}
+
+/*
+ * 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;
+	__be32		err2;
+	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, NFSD_MAY_CREATE);
+	if (err)
+		goto out;
+
+	dentry = fhp->fh_dentry;
+	dirp = dentry->d_inode;
+
+	err = nfserr_notdir;
+	if (!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;
+
+	err = nfserr_inval;
+	if (!S_ISREG(type) && !S_ISDIR(type) && !special_file(type)) {
+		printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
+		       type);
+		goto out;
+	}
+
+	host_err = fh_want_write(fhp);
+	if (host_err)
+		goto out_nfserr;
+
+	/*
+	 * Get the dir op function pointer.
+	 */
+	err = 0;
+	switch (type) {
+	case S_IFREG:
+		host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
+		if (!host_err)
+			nfsd_check_ignore_resizing(iap);
+		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;
+	}
+	if (host_err < 0) {
+		fh_drop_write(fhp);
+		goto out_nfserr;
+	}
+
+	err = nfsd_create_setattr(rqstp, resfhp, iap);
+
+	/*
+	 * nfsd_setattr already committed the child.  Transactional filesystems
+	 * had a chance to commit changes for both parent and child
+	 * simultaneously making the following commit_metadata a noop.
+	 */
+	err2 = nfserrno(commit_metadata(fhp));
+	if (err2)
+		err = err2;
+	fh_drop_write(fhp);
+	/*
+	 * 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
+
+static inline int nfsd_create_is_exclusive(int createmode)
+{
+	return createmode == NFS3_CREATE_EXCLUSIVE
+	       || createmode == NFS4_CREATE_EXCLUSIVE4_1;
+}
+
+/*
+ * NFSv3 and NFSv4 version of nfsd_create
+ */
+__be32
+do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		char *fname, int flen, struct iattr *iap,
+		struct svc_fh *resfhp, int createmode, u32 *verifier,
+	        bool *truncp, bool *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, NFSD_MAY_EXEC);
+	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->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;
+
+	/* If file doesn't exist, check for permissions to create one */
+	if (!dchild->d_inode) {
+		err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
+		if (err)
+			goto out;
+	}
+
+	err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
+	if (err)
+		goto out;
+
+	if (nfsd_create_is_exclusive(createmode)) {
+		/* 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;
+	}
+	
+	host_err = fh_want_write(fhp);
+	if (host_err)
+		goto out_nfserr;
+	if (dchild->d_inode) {
+		err = 0;
+
+		switch (createmode) {
+		case NFS3_CREATE_UNCHECKED:
+			if (! S_ISREG(dchild->d_inode->i_mode))
+				goto out;
+			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 ) {
+				if (created)
+					*created = 1;
+				break;
+			}
+		case NFS4_CREATE_EXCLUSIVE4_1:
+			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 ) {
+				if (created)
+					*created = 1;
+				goto set_attr;
+			}
+			 /* fallthru */
+		case NFS3_CREATE_GUARDED:
+			err = nfserr_exist;
+		}
+		fh_drop_write(fhp);
+		goto out;
+	}
+
+	host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
+	if (host_err < 0) {
+		fh_drop_write(fhp);
+		goto out_nfserr;
+	}
+	if (created)
+		*created = 1;
+
+	nfsd_check_ignore_resizing(iap);
+
+	if (nfsd_create_is_exclusive(createmode)) {
+		/* 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_attr:
+	err = nfsd_create_setattr(rqstp, resfhp, iap);
+
+	/*
+	 * nfsd_setattr already committed the child (and possibly also the parent).
+	 */
+	if (!err)
+		err = nfserrno(commit_metadata(fhp));
+
+	fh_drop_write(fhp);
+	/*
+	 * 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 inode	*inode;
+	mm_segment_t	oldfs;
+	__be32		err;
+	int		host_err;
+	struct path path;
+
+	err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
+	if (err)
+		goto out;
+
+	path.mnt = fhp->fh_export->ex_path.mnt;
+	path.dentry = fhp->fh_dentry;
+	inode = path.dentry->d_inode;
+
+	err = nfserr_inval;
+	if (!inode->i_op->readlink)
+		goto out;
+
+	touch_atime(&path);
+	/* 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(path.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;
+
+	err = nfserr_noent;
+	if (!flen || !plen)
+		goto out;
+	err = nfserr_exist;
+	if (isdotent(fname, flen))
+		goto out;
+
+	err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_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;
+
+	host_err = fh_want_write(fhp);
+	if (host_err)
+		goto out_nfserr;
+
+	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);
+			kfree(path_alloced);
+		}
+	} else
+		host_err = vfs_symlink(dentry->d_inode, dnew, path);
+	err = nfserrno(host_err);
+	if (!err)
+		err = nfserrno(commit_metadata(fhp));
+	fh_unlock(fhp);
+
+	fh_drop_write(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;
+	__be32		err;
+	int		host_err;
+
+	err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
+	if (err)
+		goto out;
+	err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP);
+	if (err)
+		goto out;
+	err = nfserr_isdir;
+	if (S_ISDIR(tfhp->fh_dentry->d_inode->i_mode))
+		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;
+
+	host_err = fh_want_write(tfhp);
+	if (host_err) {
+		err = nfserrno(host_err);
+		goto out_dput;
+	}
+	err = nfserr_noent;
+	if (!dold->d_inode)
+		goto out_drop_write;
+	host_err = nfsd_break_lease(dold->d_inode);
+	if (host_err) {
+		err = nfserrno(host_err);
+		goto out_drop_write;
+	}
+	host_err = vfs_link(dold, dirp, dnew);
+	if (!host_err) {
+		err = nfserrno(commit_metadata(ffhp));
+		if (!err)
+			err = nfserrno(commit_metadata(tfhp));
+	} else {
+		if (host_err == -EXDEV && rqstp->rq_vers == 2)
+			err = nfserr_acces;
+		else
+			err = nfserrno(host_err);
+	}
+out_drop_write:
+	fh_drop_write(tfhp);
+out_dput:
+	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, NFSD_MAY_REMOVE);
+	if (err)
+		goto out;
+	err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_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;
+
+	host_err = -EXDEV;
+	if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
+		goto out_dput_new;
+	host_err = fh_want_write(ffhp);
+	if (host_err)
+		goto out_dput_new;
+
+	host_err = nfsd_break_lease(odentry->d_inode);
+	if (host_err)
+		goto out_drop_write;
+	if (ndentry->d_inode) {
+		host_err = nfsd_break_lease(ndentry->d_inode);
+		if (host_err)
+			goto out_drop_write;
+	}
+	host_err = vfs_rename(fdir, odentry, tdir, ndentry);
+	if (!host_err) {
+		host_err = commit_metadata(tfhp);
+		if (!host_err)
+			host_err = commit_metadata(ffhp);
+	}
+out_drop_write:
+	fh_drop_write(ffhp);
+ 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, NFSD_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;
+
+	host_err = fh_want_write(fhp);
+	if (host_err)
+		goto out_put;
+
+	host_err = nfsd_break_lease(rdentry->d_inode);
+	if (host_err)
+		goto out_drop_write;
+	if (type != S_IFDIR)
+		host_err = vfs_unlink(dirp, rdentry);
+	else
+		host_err = vfs_rmdir(dirp, rdentry);
+	if (!host_err)
+		host_err = commit_metadata(fhp);
+out_drop_write:
+	fh_drop_write(fhp);
+out_put:
+	dput(rdentry);
+
+out_nfserr:
+	err = nfserrno(host_err);
+out:
+	return err;
+}
+
+/*
+ * We do this buffering because we must not call back into the file
+ * system's ->lookup() method from the filldir callback. That may well
+ * deadlock a number of file systems.
+ *
+ * This is based heavily on the implementation of same in XFS.
+ */
+struct buffered_dirent {
+	u64		ino;
+	loff_t		offset;
+	int		namlen;
+	unsigned int	d_type;
+	char		name[];
+};
+
+struct readdir_data {
+	char		*dirent;
+	size_t		used;
+	int		full;
+};
+
+static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen,
+				 loff_t offset, u64 ino, unsigned int d_type)
+{
+	struct readdir_data *buf = __buf;
+	struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
+	unsigned int reclen;
+
+	reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
+	if (buf->used + reclen > PAGE_SIZE) {
+		buf->full = 1;
+		return -EINVAL;
+	}
+
+	de->namlen = namlen;
+	de->offset = offset;
+	de->ino = ino;
+	de->d_type = d_type;
+	memcpy(de->name, name, namlen);
+	buf->used += reclen;
+
+	return 0;
+}
+
+static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func,
+				    struct readdir_cd *cdp, loff_t *offsetp)
+{
+	struct readdir_data buf;
+	struct buffered_dirent *de;
+	int host_err;
+	int size;
+	loff_t offset;
+
+	buf.dirent = (void *)__get_free_page(GFP_KERNEL);
+	if (!buf.dirent)
+		return nfserrno(-ENOMEM);
+
+	offset = *offsetp;
+
+	while (1) {
+		struct inode *dir_inode = file->f_path.dentry->d_inode;
+		unsigned int reclen;
+
+		cdp->err = nfserr_eof; /* will be cleared on successful read */
+		buf.used = 0;
+		buf.full = 0;
+
+		host_err = vfs_readdir(file, nfsd_buffered_filldir, &buf);
+		if (buf.full)
+			host_err = 0;
+
+		if (host_err < 0)
+			break;
+
+		size = buf.used;
+
+		if (!size)
+			break;
+
+		/*
+		 * Various filldir functions may end up calling back into
+		 * lookup_one_len() and the file system's ->lookup() method.
+		 * These expect i_mutex to be held, as it would within readdir.
+		 */
+		host_err = mutex_lock_killable(&dir_inode->i_mutex);
+		if (host_err)
+			break;
+
+		de = (struct buffered_dirent *)buf.dirent;
+		while (size > 0) {
+			offset = de->offset;
+
+			if (func(cdp, de->name, de->namlen, de->offset,
+				 de->ino, de->d_type))
+				break;
+
+			if (cdp->err != nfs_ok)
+				break;
+
+			reclen = ALIGN(sizeof(*de) + de->namlen,
+				       sizeof(u64));
+			size -= reclen;
+			de = (struct buffered_dirent *)((char *)de + reclen);
+		}
+		mutex_unlock(&dir_inode->i_mutex);
+		if (size > 0) /* We bailed out early */
+			break;
+
+		offset = vfs_llseek(file, 0, SEEK_CUR);
+	}
+
+	free_page((unsigned long)(buf.dirent));
+
+	if (host_err)
+		return nfserrno(host_err);
+
+	*offsetp = offset;
+	return cdp->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;
+	struct file	*file;
+	loff_t		offset = *offsetp;
+	int             may_flags = NFSD_MAY_READ;
+
+	/* NFSv2 only supports 32 bit cookies */
+	if (rqstp->rq_vers > 2)
+		may_flags |= NFSD_MAY_64BIT_COOKIE;
+
+	err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
+	if (err)
+		goto out;
+
+	offset = vfs_llseek(file, offset, 0);
+	if (offset < 0) {
+		err = nfserrno((int)offset);
+		goto out_close;
+	}
+
+	err = nfsd_buffered_readdir(file, func, cdp, offsetp);
+
+	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, int access)
+{
+	__be32 err;
+
+	err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
+	if (!err) {
+		struct path path = {
+			.mnt	= fhp->fh_export->ex_path.mnt,
+			.dentry	= fhp->fh_dentry,
+		};
+		if (vfs_statfs(&path, 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 & NFSD_MAY_MASK) == NFSD_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 & NFSD_MAY_READ)?	" read"  : "",
+		(acc & NFSD_MAY_WRITE)?	" write" : "",
+		(acc & NFSD_MAY_EXEC)?	" exec"  : "",
+		(acc & NFSD_MAY_SATTR)?	" sattr" : "",
+		(acc & NFSD_MAY_TRUNC)?	" trunc" : "",
+		(acc & NFSD_MAY_LOCK)?	" lock"  : "",
+		(acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
+		inode->i_mode,
+		IS_IMMUTABLE(inode)?	" immut" : "",
+		IS_APPEND(inode)?	" append" : "",
+		__mnt_is_readonly(exp->ex_path.mnt)?	" 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 & NFSD_MAY_LOCAL_ACCESS))
+		if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
+			if (exp_rdonly(rqstp, exp) ||
+			    __mnt_is_readonly(exp->ex_path.mnt))
+				return nfserr_rofs;
+			if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
+				return nfserr_perm;
+		}
+	if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
+		return nfserr_perm;
+
+	if (acc & NFSD_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 = NFSD_MAY_READ | NFSD_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 & NFSD_MAY_OWNER_OVERRIDE) &&
+	    inode->i_uid == current_fsuid())
+		return 0;
+
+	/* This assumes  NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
+	err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC));
+
+	/* Allow read access to binaries even when mode 111 */
+	if (err == -EACCES && S_ISREG(inode->i_mode) &&
+	     (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) ||
+	      acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC)))
+		err = inode_permission(inode, MAY_EXEC);
+
+	return err? nfserrno(err) : 0;
+}
+
+void
+nfsd_racache_shutdown(void)
+{
+	struct raparms *raparm, *last_raparm;
+	unsigned int i;
+
+	dprintk("nfsd: freeing readahead buffers.\n");
+
+	for (i = 0; i < RAPARM_HASH_SIZE; i++) {
+		raparm = raparm_hash[i].pb_head;
+		while(raparm) {
+			last_raparm = raparm;
+			raparm = raparm->p_next;
+			kfree(last_raparm);
+		}
+		raparm_hash[i].pb_head = NULL;
+	}
+}
+/*
+ * Initialize readahead param cache
+ */
+int
+nfsd_racache_init(int cache_size)
+{
+	int	i;
+	int	j = 0;
+	int	nperbucket;
+	struct raparms **raparm = NULL;
+
+
+	if (raparm_hash[0].pb_head)
+		return 0;
+	nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE);
+	if (nperbucket < 2)
+		nperbucket = 2;
+	cache_size = nperbucket * RAPARM_HASH_SIZE;
+
+	dprintk("nfsd: allocating %d readahead buffers.\n", cache_size);
+
+	for (i = 0; i < RAPARM_HASH_SIZE; i++) {
+		spin_lock_init(&raparm_hash[i].pb_lock);
+
+		raparm = &raparm_hash[i].pb_head;
+		for (j = 0; j < nperbucket; j++) {
+			*raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL);
+			if (!*raparm)
+				goto out_nomem;
+			raparm = &(*raparm)->p_next;
+		}
+		*raparm = NULL;
+	}
+
+	nfsdstats.ra_size = cache_size;
+	return 0;
+
+out_nomem:
+	dprintk("nfsd: kmalloc failed, freeing readahead buffers\n");
+	nfsd_racache_shutdown();
+	return -ENOMEM;
+}
+
+#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->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;
+
+	error = fh_want_write(fhp);
+	if (error)
+		goto getout;
+	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;
+		}
+	}
+	fh_drop_write(fhp);
+
+getout:
+	kfree(value);
+	return error;
+}
+#endif  /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */