#include <linux/capability.h>
  #include <linux/fs.h>
  #include <linux/posix_acl.h>
  #include "reiserfs.h"
  #include <linux/errno.h>
  #include <linux/pagemap.h>
  #include <linux/xattr.h>
  #include <linux/slab.h>
  #include <linux/posix_acl_xattr.h>
  #include "xattr.h"
  #include "acl.h"
  #include <linux/uaccess.h>
  
  static int __reiserfs_set_acl(struct reiserfs_transaction_handle *th,
  			    struct inode *inode, int type,
  			    struct posix_acl *acl);
  
  
  int
  reiserfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
  {
  	int error, error2;
  	struct reiserfs_transaction_handle th;
  	size_t jcreate_blocks;
  	int size = acl ? posix_acl_xattr_size(acl->a_count) : 0;
  
  
  	/*
  	 * 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);
  	reiserfs_write_unlock(inode->i_sb);
  	if (error == 0) {
  		error = __reiserfs_set_acl(&th, inode, type, acl);
  		reiserfs_write_lock(inode->i_sb);
  		error2 = journal_end(&th);
  		reiserfs_write_unlock(inode->i_sb);
  		if (error2)
  			error = error2;
  	}
  
  	return error;
  }
  
  /*
   * Convert from filesystem to in-memory representation.
   */
  static struct posix_acl *reiserfs_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);
  			break;
  
  		case ACL_USER:
  			value = (char *)value + sizeof(reiserfs_acl_entry);
  			if ((char *)value > end)
  				goto fail;
  			acl->a_entries[n].e_uid = 
  				make_kuid(&init_user_ns,
  					  le32_to_cpu(entry->e_id));
  			break;
  		case ACL_GROUP:
  			value = (char *)value + sizeof(reiserfs_acl_entry);
  			if ((char *)value > end)
  				goto fail;
  			acl->a_entries[n].e_gid =
  				make_kgid(&init_user_ns,
  					  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 *reiserfs_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++) {
  		const struct posix_acl_entry *acl_e = &acl->a_entries[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:
  			entry->e_id = cpu_to_le32(
  				from_kuid(&init_user_ns, acl_e->e_uid));
  			e += sizeof(reiserfs_acl_entry);
  			break;
  		case ACL_GROUP:
  			entry->e_id = cpu_to_le32(
  				from_kgid(&init_user_ns, acl_e->e_gid));
  			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;
  
  	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 = reiserfs_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;
  
  	switch (type) {
  	case ACL_TYPE_ACCESS:
  		name = POSIX_ACL_XATTR_ACCESS;
  		if (acl) {
  			error = posix_acl_update_mode(inode, &inode->i_mode, &acl);
  			if (error)
  				return error;
  		}
  		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 = reiserfs_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 *default_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;
  	}
  
  	err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
  	if (err)
  		return err;
  
  	if (default_acl) {
  		err = __reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT,
  					 default_acl);
  		posix_acl_release(default_acl);
  	}
  	if (acl) {
  		if (!err)
  			err = __reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS,
  						 acl);
  		posix_acl_release(acl);
  	}
  
  	return err;
  
  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;
  }
  
  /*
   * Called under i_mutex
   */
  int reiserfs_acl_chmod(struct inode *inode)
  {
  	if (IS_PRIVATE(inode))
  		return 0;
  	if (get_inode_sd_version(inode) == STAT_DATA_V1 ||
  	    !reiserfs_posixacl(inode->i_sb))
  		return 0;
  
  	return posix_acl_chmod(inode, inode->i_mode);
  }