#include <linux/fs.h>

  #include <linux/gfp.h>

  #include <linux/nfs.h>
  #include <linux/nfs3.h>
  #include <linux/nfs_fs.h>

  #include <linux/posix_acl_xattr.h>

  #include <linux/nfsacl.h>

  #include "internal.h"

  #include "nfs3_fs.h"

  #define NFSDBG_FACILITY	NFSDBG_PROC

  /*
   * nfs3_prepare_get_acl, nfs3_complete_get_acl, nfs3_abort_get_acl: Helpers for
   * caching get_acl results in a race-free way.  See fs/posix_acl.c:get_acl()
   * for explanations.
   */
  static void nfs3_prepare_get_acl(struct posix_acl **p)
  {
  	struct posix_acl *sentinel = uncached_acl_sentinel(current);
  
  	if (cmpxchg(p, ACL_NOT_CACHED, sentinel) != ACL_NOT_CACHED) {
  		/* Not the first reader or sentinel already in place. */
  	}
  }
  
  static void nfs3_complete_get_acl(struct posix_acl **p, struct posix_acl *acl)
  {
  	struct posix_acl *sentinel = uncached_acl_sentinel(current);
  
  	/* Only cache the ACL if our sentinel is still in place. */
  	posix_acl_dup(acl);
  	if (cmpxchg(p, sentinel, acl) != sentinel)
  		posix_acl_release(acl);
  }
  
  static void nfs3_abort_get_acl(struct posix_acl **p)
  {
  	struct posix_acl *sentinel = uncached_acl_sentinel(current);
  
  	/* Remove our sentinel upon failure. */
  	cmpxchg(p, sentinel, ACL_NOT_CACHED);
  }

  struct posix_acl *nfs3_get_acl(struct inode *inode, int type)

  {
  	struct nfs_server *server = NFS_SERVER(inode);

  	struct page *pages[NFSACL_MAXPAGES] = { };
  	struct nfs3_getaclargs args = {
  		.fh = NFS_FH(inode),
  		/* The xdr layer may allocate pages here. */
  		.pages = pages,
  	};
  	struct nfs3_getaclres res = {

  		NULL,

  	};

  	struct rpc_message msg = {
  		.rpc_argp	= &args,
  		.rpc_resp	= &res,
  	};

  	int status, count;
  
  	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
  		return ERR_PTR(-EOPNOTSUPP);

  	status = nfs_revalidate_inode(server, inode);
  	if (status < 0)
  		return ERR_PTR(status);

  	/*
  	 * Only get the access acl when explicitly requested: We don't
  	 * need it for access decisions, and only some applications use
  	 * it. Applications which request the access acl first are not
  	 * penalized from this optimization.
  	 */
  	if (type == ACL_TYPE_ACCESS)
  		args.mask |= NFS_ACLCNT|NFS_ACL;
  	if (S_ISDIR(inode->i_mode))
  		args.mask |= NFS_DFACLCNT|NFS_DFACL;
  	if (args.mask == 0)
  		return NULL;

  
  	dprintk("NFS call getacl
  ");

  	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];

  	res.fattr = nfs_alloc_fattr();
  	if (res.fattr == NULL)
  		return ERR_PTR(-ENOMEM);

  	if (args.mask & NFS_ACL)
  		nfs3_prepare_get_acl(&inode->i_acl);
  	if (args.mask & NFS_DFACL)
  		nfs3_prepare_get_acl(&inode->i_default_acl);

  	status = rpc_call_sync(server->client_acl, &msg, 0);

  	dprintk("NFS reply getacl: %d
  ", status);
  
  	/* pages may have been allocated at the xdr layer. */
  	for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
  		__free_page(args.pages[count]);
  
  	switch (status) {
  		case 0:

  			status = nfs_refresh_inode(inode, res.fattr);

  			break;
  		case -EPFNOSUPPORT:
  		case -EPROTONOSUPPORT:
  			dprintk("NFS_V3_ACL extension not supported; disabling
  ");
  			server->caps &= ~NFS_CAP_ACLS;
  		case -ENOTSUPP:
  			status = -EOPNOTSUPP;
  		default:
  			goto getout;
  	}
  	if ((args.mask & res.mask) != args.mask) {
  		status = -EIO;
  		goto getout;
  	}
  
  	if (res.acl_access != NULL) {

  		if ((posix_acl_equiv_mode(res.acl_access, NULL) == 0) ||

  		    res.acl_access->a_count == 0) {

  			posix_acl_release(res.acl_access);
  			res.acl_access = NULL;
  		}
  	}

  	if (res.mask & NFS_ACL)

  		nfs3_complete_get_acl(&inode->i_acl, res.acl_access);

  	else
  		forget_cached_acl(inode, ACL_TYPE_ACCESS);

  	if (res.mask & NFS_DFACL)

  		nfs3_complete_get_acl(&inode->i_default_acl, res.acl_default);

  	else
  		forget_cached_acl(inode, ACL_TYPE_DEFAULT);
  
  	nfs_free_fattr(res.fattr);
  	if (type == ACL_TYPE_ACCESS) {
  		posix_acl_release(res.acl_default);
  		return res.acl_access;
  	} else {
  		posix_acl_release(res.acl_access);
  		return res.acl_default;

  	}
  
  getout:

  	nfs3_abort_get_acl(&inode->i_acl);
  	nfs3_abort_get_acl(&inode->i_default_acl);

  	posix_acl_release(res.acl_access);
  	posix_acl_release(res.acl_default);

  	nfs_free_fattr(res.fattr);

  	return ERR_PTR(status);

  }

  static int __nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,

  		struct posix_acl *dfacl)

  {
  	struct nfs_server *server = NFS_SERVER(inode);

  	struct nfs_fattr *fattr;

  	struct page *pages[NFSACL_MAXPAGES];

  	struct nfs3_setaclargs args = {
  		.inode = inode,
  		.mask = NFS_ACL,
  		.acl_access = acl,
  		.pages = pages,
  	};

  	struct rpc_message msg = {
  		.rpc_argp	= &args,
  		.rpc_resp	= &fattr,
  	};

  	int status = 0;
  
  	if (acl == NULL && (!S_ISDIR(inode->i_mode) || dfacl == NULL))
  		goto out;

  
  	status = -EOPNOTSUPP;
  	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
  		goto out;

  	/* We are doing this here because XDR marshalling does not
  	 * return any results, it BUGs. */

  	status = -ENOSPC;
  	if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
  		goto out;
  	if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
  		goto out;
  	if (S_ISDIR(inode->i_mode)) {
  		args.mask |= NFS_DFACL;
  		args.acl_default = dfacl;

  		args.len = nfsacl_size(acl, dfacl);
  	} else
  		args.len = nfsacl_size(acl, NULL);
  
  	if (args.len > NFS_ACL_INLINE_BUFSIZE) {
  		unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
  
  		status = -ENOMEM;
  		do {
  			args.pages[args.npages] = alloc_page(GFP_KERNEL);
  			if (args.pages[args.npages] == NULL)
  				goto out_freepages;
  			args.npages++;
  		} while (args.npages < npages);

  	}
  
  	dprintk("NFS call setacl
  ");

  	status = -ENOMEM;
  	fattr = nfs_alloc_fattr();
  	if (fattr == NULL)
  		goto out_freepages;

  	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];

  	msg.rpc_resp = fattr;

  	status = rpc_call_sync(server->client_acl, &msg, 0);

  	nfs_access_zap_cache(inode);
  	nfs_zap_acl_cache(inode);

  	dprintk("NFS reply setacl: %d
  ", status);

  	switch (status) {
  		case 0:

  			status = nfs_refresh_inode(inode, fattr);

  			set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
  			set_cached_acl(inode, ACL_TYPE_DEFAULT, dfacl);

  			break;
  		case -EPFNOSUPPORT:
  		case -EPROTONOSUPPORT:
  			dprintk("NFS_V3_ACL SETACL RPC not supported"
  					"(will not retry)
  ");
  			server->caps &= ~NFS_CAP_ACLS;
  		case -ENOTSUPP:
  			status = -EOPNOTSUPP;
  	}

  	nfs_free_fattr(fattr);

  out_freepages:
  	while (args.npages != 0) {
  		args.npages--;
  		__free_page(args.pages[args.npages]);
  	}

  out:
  	return status;
  }

  int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
  		struct posix_acl *dfacl)
  {
  	int ret;
  	ret = __nfs3_proc_setacls(inode, acl, dfacl);
  	return (ret == -EOPNOTSUPP) ? 0 : ret;
  
  }

  int nfs3_set_acl(struct inode *inode, struct posix_acl *acl, int type)

  {
  	struct posix_acl *alloc = NULL, *dfacl = NULL;
  	int status;
  
  	if (S_ISDIR(inode->i_mode)) {
  		switch(type) {

  		case ACL_TYPE_ACCESS:
  			alloc = dfacl = get_acl(inode, ACL_TYPE_DEFAULT);
  			if (IS_ERR(alloc))
  				goto fail;
  			break;
  
  		case ACL_TYPE_DEFAULT:
  			dfacl = acl;
  			alloc = acl = get_acl(inode, ACL_TYPE_ACCESS);
  			if (IS_ERR(alloc))
  				goto fail;
  			break;

  		}

  	}

  
  	if (acl == NULL) {
  		alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
  		if (IS_ERR(alloc))
  			goto fail;
  	}

  	status = __nfs3_proc_setacls(inode, acl, dfacl);

  	posix_acl_release(alloc);
  	return status;
  
  fail:
  	return PTR_ERR(alloc);
  }

  const struct xattr_handler *nfs3_xattr_handlers[] = {
  	&posix_acl_access_xattr_handler,
  	&posix_acl_default_xattr_handler,
  	NULL,
  };

  
  static int
  nfs3_list_one_acl(struct inode *inode, int type, const char *name, void *data,
  		size_t size, ssize_t *result)
  {
  	struct posix_acl *acl;
  	char *p = data + *result;
  
  	acl = get_acl(inode, type);

  	if (IS_ERR_OR_NULL(acl))

  		return 0;
  
  	posix_acl_release(acl);
  
  	*result += strlen(name);
  	*result += 1;
  	if (!size)
  		return 0;
  	if (*result > size)
  		return -ERANGE;
  
  	strcpy(p, name);
  	return 0;
  }
  
  ssize_t
  nfs3_listxattr(struct dentry *dentry, char *data, size_t size)
  {

  	struct inode *inode = d_inode(dentry);

  	ssize_t result = 0;
  	int error;
  
  	error = nfs3_list_one_acl(inode, ACL_TYPE_ACCESS,

  			XATTR_NAME_POSIX_ACL_ACCESS, data, size, &result);

  	if (error)
  		return error;
  
  	error = nfs3_list_one_acl(inode, ACL_TYPE_DEFAULT,

  			XATTR_NAME_POSIX_ACL_DEFAULT, data, size, &result);

  	if (error)
  		return error;
  	return result;
  }