#include <linux/capability.h>

  #include <linux/fs.h>
  #include <linux/posix_acl.h>
  #include <linux/reiserfs_fs.h>
  #include <linux/errno.h>
  #include <linux/pagemap.h>
  #include <linux/xattr.h>

  #include <linux/slab.h>

  #include <linux/posix_acl_xattr.h>

  #include <linux/reiserfs_xattr.h>
  #include <linux/reiserfs_acl.h>
  #include <asm/uaccess.h>

  static int reiserfs_set_acl(struct reiserfs_transaction_handle *th,
  			    struct inode *inode, int type,

  			    struct posix_acl *acl);

  
  static int

  posix_acl_set(struct dentry *dentry, const char *name, const void *value,
  		size_t size, int flags, int type)

  {

  	struct inode *inode = dentry->d_inode;

  	struct posix_acl *acl;

  	int error, error2;
  	struct reiserfs_transaction_handle th;
  	size_t jcreate_blocks;

  	if (!reiserfs_posixacl(inode->i_sb))
  		return -EOPNOTSUPP;

  	if (!inode_owner_or_capable(inode))

  		return -EPERM;
  
  	if (value) {
  		acl = posix_acl_from_xattr(value, size);
  		if (IS_ERR(acl)) {
  			return PTR_ERR(acl);
  		} else if (acl) {
  			error = posix_acl_valid(acl);
  			if (error)
  				goto release_and_out;
  		}
  	} else
  		acl = NULL;

  	/* Pessimism: We can't assume that anything from the xattr root up
  	 * has been created. */
  
  	jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) +
  			 reiserfs_xattr_nblocks(inode, size) * 2;
  
  	reiserfs_write_lock(inode->i_sb);
  	error = journal_begin(&th, inode->i_sb, jcreate_blocks);
  	if (error == 0) {
  		error = reiserfs_set_acl(&th, inode, type, acl);
  		error2 = journal_end(&th, inode->i_sb, jcreate_blocks);
  		if (error2)
  			error = error2;
  	}
  	reiserfs_write_unlock(inode->i_sb);

        release_and_out:

  	posix_acl_release(acl);
  	return error;
  }

  static int

  posix_acl_get(struct dentry *dentry, const char *name, void *buffer,
  		size_t size, int type)

  {
  	struct posix_acl *acl;
  	int error;

  	if (!reiserfs_posixacl(dentry->d_sb))

  		return -EOPNOTSUPP;

  	acl = reiserfs_get_acl(dentry->d_inode, type);

  	if (IS_ERR(acl))
  		return PTR_ERR(acl);
  	if (acl == NULL)
  		return -ENODATA;
  	error = posix_acl_to_xattr(acl, buffer, size);
  	posix_acl_release(acl);
  
  	return error;
  }

  /*
   * Convert from filesystem to in-memory representation.
   */

  static struct posix_acl *posix_acl_from_disk(const void *value, size_t size)

  {
  	const char *end = (char *)value + size;
  	int n, count;
  	struct posix_acl *acl;
  
  	if (!value)
  		return NULL;
  	if (size < sizeof(reiserfs_acl_header))

  		return ERR_PTR(-EINVAL);
  	if (((reiserfs_acl_header *) value)->a_version !=

  	    cpu_to_le32(REISERFS_ACL_VERSION))
  		return ERR_PTR(-EINVAL);
  	value = (char *)value + sizeof(reiserfs_acl_header);
  	count = reiserfs_acl_count(size);
  	if (count < 0)
  		return ERR_PTR(-EINVAL);
  	if (count == 0)
  		return NULL;
  	acl = posix_acl_alloc(count, GFP_NOFS);
  	if (!acl)
  		return ERR_PTR(-ENOMEM);

  	for (n = 0; n < count; n++) {
  		reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value;

  		if ((char *)value + sizeof(reiserfs_acl_entry_short) > end)
  			goto fail;

  		acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);

  		acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);

  		switch (acl->a_entries[n].e_tag) {
  		case ACL_USER_OBJ:
  		case ACL_GROUP_OBJ:
  		case ACL_MASK:
  		case ACL_OTHER:
  			value = (char *)value +
  			    sizeof(reiserfs_acl_entry_short);
  			acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
  			break;
  
  		case ACL_USER:
  		case ACL_GROUP:
  			value = (char *)value + sizeof(reiserfs_acl_entry);
  			if ((char *)value > end)

  				goto fail;

  			acl->a_entries[n].e_id = le32_to_cpu(entry->e_id);
  			break;
  
  		default:
  			goto fail;

  		}
  	}
  	if (value != end)
  		goto fail;
  	return acl;

        fail:

  	posix_acl_release(acl);
  	return ERR_PTR(-EINVAL);
  }
  
  /*
   * Convert from in-memory to filesystem representation.
   */

  static void *posix_acl_to_disk(const struct posix_acl *acl, size_t * size)

  {
  	reiserfs_acl_header *ext_acl;
  	char *e;
  	int n;
  
  	*size = reiserfs_acl_size(acl->a_count);

  	ext_acl = kmalloc(sizeof(reiserfs_acl_header) +

  						  acl->a_count *
  						  sizeof(reiserfs_acl_entry),
  						  GFP_NOFS);

  	if (!ext_acl)
  		return ERR_PTR(-ENOMEM);
  	ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION);
  	e = (char *)ext_acl + sizeof(reiserfs_acl_header);

  	for (n = 0; n < acl->a_count; n++) {
  		reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e;
  		entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);

  		entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);

  		switch (acl->a_entries[n].e_tag) {
  		case ACL_USER:
  		case ACL_GROUP:
  			entry->e_id = cpu_to_le32(acl->a_entries[n].e_id);
  			e += sizeof(reiserfs_acl_entry);
  			break;
  
  		case ACL_USER_OBJ:
  		case ACL_GROUP_OBJ:
  		case ACL_MASK:
  		case ACL_OTHER:
  			e += sizeof(reiserfs_acl_entry_short);
  			break;
  
  		default:
  			goto fail;

  		}
  	}
  	return (char *)ext_acl;

        fail:

  	kfree(ext_acl);
  	return ERR_PTR(-EINVAL);
  }
  
  /*
   * Inode operation get_posix_acl().
   *

   * inode->i_mutex: down

   * BKL held [before 2.5.x]
   */

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

  {
  	char *name, *value;

  	struct posix_acl *acl;

  	int size;

  	int retval;

  	acl = get_cached_acl(inode, type);
  	if (acl != ACL_NOT_CACHED)
  		return acl;

  	switch (type) {
  	case ACL_TYPE_ACCESS:
  		name = POSIX_ACL_XATTR_ACCESS;

  		break;
  	case ACL_TYPE_DEFAULT:
  		name = POSIX_ACL_XATTR_DEFAULT;

  		break;
  	default:

  		BUG();

  	}

  	size = reiserfs_xattr_get(inode, name, NULL, 0);

  	if (size < 0) {

  		if (size == -ENODATA || size == -ENOSYS) {

  			set_cached_acl(inode, type, NULL);

  			return NULL;
  		}
  		return ERR_PTR(size);
  	}

  	value = kmalloc(size, GFP_NOFS);
  	if (!value)
  		return ERR_PTR(-ENOMEM);

  
  	retval = reiserfs_xattr_get(inode, name, value, size);
  	if (retval == -ENODATA || retval == -ENOSYS) {
  		/* This shouldn't actually happen as it should have
  		   been caught above.. but just in case */
  		acl = NULL;

  	} else if (retval < 0) {

  		acl = ERR_PTR(retval);
  	} else {
  		acl = posix_acl_from_disk(value, retval);

  	}

  	if (!IS_ERR(acl))
  		set_cached_acl(inode, type, acl);

  
  	kfree(value);
  	return acl;
  }
  
  /*
   * Inode operation set_posix_acl().
   *

   * inode->i_mutex: down

   * BKL held [before 2.5.x]
   */
  static int

  reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode,
  		 int type, struct posix_acl *acl)

  {

  	char *name;

  	void *value = NULL;

  	size_t size = 0;

  	int error;

  
  	if (S_ISLNK(inode->i_mode))
  		return -EOPNOTSUPP;

  	switch (type) {
  	case ACL_TYPE_ACCESS:
  		name = POSIX_ACL_XATTR_ACCESS;

  		if (acl) {

  			error = posix_acl_equiv_mode(acl, &inode->i_mode);

  			if (error < 0)
  				return error;
  			else {

  				if (error == 0)
  					acl = NULL;
  			}
  		}
  		break;
  	case ACL_TYPE_DEFAULT:
  		name = POSIX_ACL_XATTR_DEFAULT;

  		if (!S_ISDIR(inode->i_mode))
  			return acl ? -EACCES : 0;
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	if (acl) {
  		value = posix_acl_to_disk(acl, &size);
  		if (IS_ERR(value))
  			return (int)PTR_ERR(value);

  	}

  	error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0);

  
  	/*
  	 * Ensure that the inode gets dirtied if we're only using
  	 * the mode bits and an old ACL didn't exist. We don't need
  	 * to check if the inode is hashed here since we won't get
  	 * called by reiserfs_inherit_default_acl().
  	 */
  	if (error == -ENODATA) {
  		error = 0;
  		if (type == ACL_TYPE_ACCESS) {
  			inode->i_ctime = CURRENT_TIME_SEC;

  			mark_inode_dirty(inode);

  		}
  	}

  	kfree(value);

  	if (!error)

  		set_cached_acl(inode, type, acl);

  
  	return error;
  }

  /* dir->i_mutex: locked,

   * inode is new and not released into the wild yet */
  int

  reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th,
  			     struct inode *dir, struct dentry *dentry,

  			     struct inode *inode)

  {

  	struct posix_acl *acl;
  	int err = 0;
  
  	/* ACLs only get applied to files and directories */
  	if (S_ISLNK(inode->i_mode))
  		return 0;
  
  	/* ACLs can only be used on "new" objects, so if it's an old object
  	 * there is nothing to inherit from */
  	if (get_inode_sd_version(dir) == STAT_DATA_V1)
  		goto apply_umask;
  
  	/* Don't apply ACLs to objects in the .reiserfs_priv tree.. This
  	 * would be useless since permissions are ignored, and a pain because
  	 * it introduces locking cycles */

  	if (IS_PRIVATE(dir)) {
  		inode->i_flags |= S_PRIVATE;

  		goto apply_umask;
  	}
  
  	acl = reiserfs_get_acl(dir, ACL_TYPE_DEFAULT);

  	if (IS_ERR(acl))

  		return PTR_ERR(acl);

  
  	if (acl) {

  		/* Copy the default ACL to the default ACL of a new directory */
  		if (S_ISDIR(inode->i_mode)) {

  			err = reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT,
  					       acl);

  			if (err)
  				goto cleanup;
  		}
  
  		/* Now we reconcile the new ACL and the mode,
  		   potentially modifying both */

  		err = posix_acl_create(&acl, GFP_NOFS, &inode->i_mode);

  		if (err < 0)
  			return err;

  		/* If we need an ACL.. */
  		if (err > 0)
  			err = reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS, acl);

  	      cleanup:
  		posix_acl_release(acl);
  	} else {
  	      apply_umask:
  		/* no ACL, apply umask */

  		inode->i_mode &= ~current_umask();

  	}
  
  	return err;

  }

  /* This is used to cache the default acl before a new object is created.
   * The biggest reason for this is to get an idea of how many blocks will
   * actually be required for the create operation if we must inherit an ACL.
   * An ACL write can add up to 3 object creations and an additional file write
   * so we'd prefer not to reserve that many blocks in the journal if we can.
   * It also has the advantage of not loading the ACL with a transaction open,
   * this may seem silly, but if the owner of the directory is doing the
   * creation, the ACL may not be loaded since the permissions wouldn't require
   * it.
   * We return the number of blocks required for the transaction.
   */

  int reiserfs_cache_default_acl(struct inode *inode)

  {

  	struct posix_acl *acl;
  	int nblocks = 0;
  
  	if (IS_PRIVATE(inode))
  		return 0;
  
  	acl = reiserfs_get_acl(inode, ACL_TYPE_DEFAULT);
  
  	if (acl && !IS_ERR(acl)) {
  		int size = reiserfs_acl_size(acl->a_count);
  
  		/* Other xattrs can be created during inode creation. We don't
  		 * want to claim too many blocks, so we check to see if we
  		 * we need to create the tree to the xattrs, and then we
  		 * just want two files. */
  		nblocks = reiserfs_xattr_jcreate_nblocks(inode);
  		nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb);
  
  		REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
  
  		/* We need to account for writes + bitmaps for two files */
  		nblocks += reiserfs_xattr_nblocks(inode, size) * 4;
  		posix_acl_release(acl);

  	}

  	return nblocks;

  }

  int reiserfs_acl_chmod(struct inode *inode)

  {

  	struct reiserfs_transaction_handle th;
  	struct posix_acl *acl;
  	size_t size;
  	int depth;

  	int error;

  	if (S_ISLNK(inode->i_mode))
  		return -EOPNOTSUPP;

  	if (get_inode_sd_version(inode) == STAT_DATA_V1 ||
  	    !reiserfs_posixacl(inode->i_sb)) {
  		return 0;

  	}

  	reiserfs_write_unlock(inode->i_sb);

  	acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);

  	reiserfs_write_lock(inode->i_sb);

  	if (!acl)
  		return 0;
  	if (IS_ERR(acl))
  		return PTR_ERR(acl);

  	error = posix_acl_chmod(&acl, GFP_NOFS, inode->i_mode);
  	if (error)
  		return error;
  
  	size = reiserfs_xattr_nblocks(inode, reiserfs_acl_size(acl->a_count));
  	depth = reiserfs_write_lock_once(inode->i_sb);
  	error = journal_begin(&th, inode->i_sb, size * 2);

  	if (!error) {

  		int error2;
  		error = reiserfs_set_acl(&th, inode, ACL_TYPE_ACCESS, acl);
  		error2 = journal_end(&th, inode->i_sb, size * 2);
  		if (error2)
  			error = error2;

  	}

  	reiserfs_write_unlock_once(inode->i_sb, depth);
  	posix_acl_release(acl);

  	return error;

  }

  static size_t posix_acl_access_list(struct dentry *dentry, char *list,

  				    size_t list_size, const char *name,

  				    size_t name_len, int type)

  {

  	const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);

  	if (!reiserfs_posixacl(dentry->d_sb))

  		return 0;

  	if (list && size <= list_size)
  		memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
  	return size;

  }

  const struct xattr_handler reiserfs_posix_acl_access_handler = {

  	.prefix = POSIX_ACL_XATTR_ACCESS,

  	.flags = ACL_TYPE_ACCESS,
  	.get = posix_acl_get,
  	.set = posix_acl_set,

  	.list = posix_acl_access_list,
  };

  static size_t posix_acl_default_list(struct dentry *dentry, char *list,

  				     size_t list_size, const char *name,

  				     size_t name_len, int type)

  {

  	const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);

  	if (!reiserfs_posixacl(dentry->d_sb))

  		return 0;

  	if (list && size <= list_size)
  		memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
  	return size;

  }

  const struct xattr_handler reiserfs_posix_acl_default_handler = {

  	.prefix = POSIX_ACL_XATTR_DEFAULT,

  	.flags = ACL_TYPE_DEFAULT,
  	.get = posix_acl_get,
  	.set = posix_acl_set,

  	.list = posix_acl_default_list,
  };