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root/fs/jfs/acl.c

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DEFINITIONS

This source file includes following definitions.
  1. jfs_get_acl
  2. jfs_set_acl
  3. jfs_check_acl
  4. jfs_permission
  5. jfs_init_acl
  6. jfs_acl_chmod
  7. jfs_setattr

/*
 *   Copyright (C) International Business Machines  Corp., 2002-2004
 *   Copyright (C) Andreas Gruenbacher, 2001
 *   Copyright (C) Linus Torvalds, 1991, 1992
 *
 *   This program is free software;  you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program;  if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/quotaops.h>
#include <linux/posix_acl_xattr.h>
#include "jfs_incore.h"
#include "jfs_txnmgr.h"
#include "jfs_xattr.h"
#include "jfs_acl.h"

static struct posix_acl *jfs_get_acl(struct inode *inode, int type)
{
        struct posix_acl *acl;
        char *ea_name;
        struct jfs_inode_info *ji = JFS_IP(inode);
        struct posix_acl **p_acl;
        int size;
        char *value = NULL;

        switch(type) {
                case ACL_TYPE_ACCESS:
                        ea_name = POSIX_ACL_XATTR_ACCESS;
                        p_acl = &ji->i_acl;
                        break;
                case ACL_TYPE_DEFAULT:
                        ea_name = POSIX_ACL_XATTR_DEFAULT;
                        p_acl = &ji->i_default_acl;
                        break;
                default:
                        return ERR_PTR(-EINVAL);
        }

        if (*p_acl != JFS_ACL_NOT_CACHED)
                return posix_acl_dup(*p_acl);

        size = __jfs_getxattr(inode, ea_name, NULL, 0);

        if (size > 0) {
                value = kmalloc(size, GFP_KERNEL);
                if (!value)
                        return ERR_PTR(-ENOMEM);
                size = __jfs_getxattr(inode, ea_name, value, size);
        }

        if (size < 0) {
                if (size == -ENODATA) {
                        *p_acl = NULL;
                        acl = NULL;
                } else
                        acl = ERR_PTR(size);
        } else {
                acl = posix_acl_from_xattr(value, size);
                if (!IS_ERR(acl))
                        *p_acl = posix_acl_dup(acl);
        }
        kfree(value);
        return acl;
}

static int jfs_set_acl(tid_t tid, struct inode *inode, int type,
                       struct posix_acl *acl)
{
        char *ea_name;
        struct jfs_inode_info *ji = JFS_IP(inode);
        struct posix_acl **p_acl;
        int rc;
        int size = 0;
        char *value = NULL;

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

        switch(type) {
                case ACL_TYPE_ACCESS:
                        ea_name = POSIX_ACL_XATTR_ACCESS;
                        p_acl = &ji->i_acl;
                        break;
                case ACL_TYPE_DEFAULT:
                        ea_name = POSIX_ACL_XATTR_DEFAULT;
                        p_acl = &ji->i_default_acl;
                        if (!S_ISDIR(inode->i_mode))
                                return acl ? -EACCES : 0;
                        break;
                default:
                        return -EINVAL;
        }
        if (acl) {
                size = posix_acl_xattr_size(acl->a_count);
                value = kmalloc(size, GFP_KERNEL);
                if (!value)
                        return -ENOMEM;
                rc = posix_acl_to_xattr(acl, value, size);
                if (rc < 0)
                        goto out;
        }
        rc = __jfs_setxattr(tid, inode, ea_name, value, size, 0);
out:
        kfree(value);

        if (!rc) {
                if (*p_acl && (*p_acl != JFS_ACL_NOT_CACHED))
                        posix_acl_release(*p_acl);
                *p_acl = posix_acl_dup(acl);
        }
        return rc;
}

static int jfs_check_acl(struct inode *inode, int mask)
{
        struct jfs_inode_info *ji = JFS_IP(inode);

        if (ji->i_acl == JFS_ACL_NOT_CACHED) {
                struct posix_acl *acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
                if (IS_ERR(acl))
                        return PTR_ERR(acl);
                posix_acl_release(acl);
        }

        if (ji->i_acl)
                return posix_acl_permission(inode, ji->i_acl, mask);
        return -EAGAIN;
}

int jfs_permission(struct inode *inode, int mask)
{
        return generic_permission(inode, mask, jfs_check_acl);
}

int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)
{
        struct posix_acl *acl = NULL;
        struct posix_acl *clone;
        mode_t mode;
        int rc = 0;

        if (S_ISLNK(inode->i_mode))
                return 0;

        acl = jfs_get_acl(dir, ACL_TYPE_DEFAULT);
        if (IS_ERR(acl))
                return PTR_ERR(acl);

        if (acl) {
                if (S_ISDIR(inode->i_mode)) {
                        rc = jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, acl);
                        if (rc)
                                goto cleanup;
                }
                clone = posix_acl_clone(acl, GFP_KERNEL);
                if (!clone) {
                        rc = -ENOMEM;
                        goto cleanup;
                }
                mode = inode->i_mode;
                rc = posix_acl_create_masq(clone, &mode);
                if (rc >= 0) {
                        inode->i_mode = mode;
                        if (rc > 0)
                                rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS,
                                                 clone);
                }
                posix_acl_release(clone);
cleanup:
                posix_acl_release(acl);
        } else
                inode->i_mode &= ~current->fs->umask;

        JFS_IP(inode)->mode2 = (JFS_IP(inode)->mode2 & 0xffff0000) |
                               inode->i_mode;

        return rc;
}

static int jfs_acl_chmod(struct inode *inode)
{
        struct posix_acl *acl, *clone;
        int rc;

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

        acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
        if (IS_ERR(acl) || !acl)
                return PTR_ERR(acl);

        clone = posix_acl_clone(acl, GFP_KERNEL);
        posix_acl_release(acl);
        if (!clone)
                return -ENOMEM;

        rc = posix_acl_chmod_masq(clone, inode->i_mode);
        if (!rc) {
                tid_t tid = txBegin(inode->i_sb, 0);
                mutex_lock(&JFS_IP(inode)->commit_mutex);
                rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, clone);
                if (!rc)
                        rc = txCommit(tid, 1, &inode, 0);
                txEnd(tid);
                mutex_unlock(&JFS_IP(inode)->commit_mutex);
        }

        posix_acl_release(clone);
        return rc;
}

int jfs_setattr(struct dentry *dentry, struct iattr *iattr)
{
        struct inode *inode = dentry->d_inode;
        int rc;

        rc = inode_change_ok(inode, iattr);
        if (rc)
                return rc;

        if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
            (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
                if (DQUOT_TRANSFER(inode, iattr))
                        return -EDQUOT;
        }

        rc = inode_setattr(inode, iattr);

        if (!rc && (iattr->ia_valid & ATTR_MODE))
                rc = jfs_acl_chmod(inode);

        return rc;
}

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