--- /dev/null
+/*
+ * Copyright IBM Corporation, 2010
+ * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2.1 of the GNU Lesser General Public License
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <net/9p/9p.h>
+#include <net/9p/client.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/posix_acl_xattr.h>
+#include "xattr.h"
+#include "acl.h"
+#include "v9fs.h"
+#include "v9fs_vfs.h"
+#include "fid.h"
+
+static struct posix_acl *__v9fs_get_acl(struct p9_fid *fid, char *name)
+{
+ ssize_t size;
+ void *value = NULL;
+ struct posix_acl *acl = NULL;
+
+ size = v9fs_fid_xattr_get(fid, name, NULL, 0);
+ if (size > 0) {
+ value = kzalloc(size, GFP_NOFS);
+ if (!value)
+ return ERR_PTR(-ENOMEM);
+ size = v9fs_fid_xattr_get(fid, name, value, size);
+ if (size > 0) {
+ acl = posix_acl_from_xattr(&init_user_ns, value, size);
+ if (IS_ERR(acl))
+ goto err_out;
+ }
+ } else if (size == -ENODATA || size == 0 ||
+ size == -ENOSYS || size == -EOPNOTSUPP) {
+ acl = NULL;
+ } else
+ acl = ERR_PTR(-EIO);
+
+err_out:
+ kfree(value);
+ return acl;
+}
+
+int v9fs_get_acl(struct inode *inode, struct p9_fid *fid)
+{
+ int retval = 0;
+ struct posix_acl *pacl, *dacl;
+ struct v9fs_session_info *v9ses;
+
+ v9ses = v9fs_inode2v9ses(inode);
+ if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) ||
+ ((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) {
+ set_cached_acl(inode, ACL_TYPE_DEFAULT, NULL);
+ set_cached_acl(inode, ACL_TYPE_ACCESS, NULL);
+ return 0;
+ }
+ /* get the default/access acl values and cache them */
+ dacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_DEFAULT);
+ pacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_ACCESS);
+
+ if (!IS_ERR(dacl) && !IS_ERR(pacl)) {
+ set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl);
+ set_cached_acl(inode, ACL_TYPE_ACCESS, pacl);
+ } else
+ retval = -EIO;
+
+ if (!IS_ERR(dacl))
+ posix_acl_release(dacl);
+
+ if (!IS_ERR(pacl))
+ posix_acl_release(pacl);
+
+ return retval;
+}
+
+static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type)
+{
+ struct posix_acl *acl;
+ /*
+ * 9p Always cache the acl value when
+ * instantiating the inode (v9fs_inode_from_fid)
+ */
+ acl = get_cached_acl(inode, type);
+ BUG_ON(acl == ACL_NOT_CACHED);
+ return acl;
+}
+
+struct posix_acl *v9fs_iop_get_acl(struct inode *inode, int type)
+{
+ struct v9fs_session_info *v9ses;
+
+ v9ses = v9fs_inode2v9ses(inode);
+ if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) ||
+ ((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) {
+ /*
+ * On access = client and acl = on mode get the acl
+ * values from the server
+ */
+ return NULL;
+ }
+ return v9fs_get_cached_acl(inode, type);
+
+}
+
+static int v9fs_set_acl(struct p9_fid *fid, int type, struct posix_acl *acl)
+{
+ int retval;
+ char *name;
+ size_t size;
+ void *buffer;
+ if (!acl)
+ return 0;
+
+ /* Set a setxattr request to server */
+ size = posix_acl_xattr_size(acl->a_count);
+ buffer = kmalloc(size, GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;
+ retval = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
+ if (retval < 0)
+ goto err_free_out;
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ name = POSIX_ACL_XATTR_ACCESS;
+ break;
+ case ACL_TYPE_DEFAULT:
+ name = POSIX_ACL_XATTR_DEFAULT;
+ break;
+ default:
+ BUG();
+ }
+ retval = v9fs_fid_xattr_set(fid, name, buffer, size, 0);
+err_free_out:
+ kfree(buffer);
+ return retval;
+}
+
+int v9fs_acl_chmod(struct inode *inode, struct p9_fid *fid)
+{
+ int retval = 0;
+ struct posix_acl *acl;
+
+ if (S_ISLNK(inode->i_mode))
+ return -EOPNOTSUPP;
+ acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);
+ if (acl) {
+ retval = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
+ if (retval)
+ return retval;
+ set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
+ retval = v9fs_set_acl(fid, ACL_TYPE_ACCESS, acl);
+ posix_acl_release(acl);
+ }
+ return retval;
+}
+
+int v9fs_set_create_acl(struct inode *inode, struct p9_fid *fid,
+ struct posix_acl *dacl, struct posix_acl *acl)
+{
+ set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl);
+ set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
+ v9fs_set_acl(fid, ACL_TYPE_DEFAULT, dacl);
+ v9fs_set_acl(fid, ACL_TYPE_ACCESS, acl);
+ return 0;
+}
+
+void v9fs_put_acl(struct posix_acl *dacl,
+ struct posix_acl *acl)
+{
+ posix_acl_release(dacl);
+ posix_acl_release(acl);
+}
+
+int v9fs_acl_mode(struct inode *dir, umode_t *modep,
+ struct posix_acl **dpacl, struct posix_acl **pacl)
+{
+ int retval = 0;
+ umode_t mode = *modep;
+ struct posix_acl *acl = NULL;
+
+ if (!S_ISLNK(mode)) {
+ acl = v9fs_get_cached_acl(dir, ACL_TYPE_DEFAULT);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ if (!acl)
+ mode &= ~current_umask();
+ }
+ if (acl) {
+ if (S_ISDIR(mode))
+ *dpacl = posix_acl_dup(acl);
+ retval = __posix_acl_create(&acl, GFP_NOFS, &mode);
+ if (retval < 0)
+ return retval;
+ if (retval > 0)
+ *pacl = acl;
+ else
+ posix_acl_release(acl);
+ }
+ *modep = mode;
+ return 0;
+}
+
+static int v9fs_remote_get_acl(struct dentry *dentry, const char *name,
+ void *buffer, size_t size, int type)
+{
+ char *full_name;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ full_name = POSIX_ACL_XATTR_ACCESS;
+ break;
+ case ACL_TYPE_DEFAULT:
+ full_name = POSIX_ACL_XATTR_DEFAULT;
+ break;
+ default:
+ BUG();
+ }
+ return v9fs_xattr_get(dentry, full_name, buffer, size);
+}
+
+static int v9fs_xattr_get_acl(struct dentry *dentry, const char *name,
+ void *buffer, size_t size, int type)
+{
+ struct v9fs_session_info *v9ses;
+ struct posix_acl *acl;
+ int error;
+
+ if (strcmp(name, "") != 0)
+ return -EINVAL;
+
+ v9ses = v9fs_dentry2v9ses(dentry);
+ /*
+ * We allow set/get/list of acl when access=client is not specified
+ */
+ if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
+ return v9fs_remote_get_acl(dentry, name, buffer, size, type);
+
+ acl = v9fs_get_cached_acl(d_inode(dentry), type);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ if (acl == NULL)
+ return -ENODATA;
+ error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
+ posix_acl_release(acl);
+
+ return error;
+}
+
+static int v9fs_remote_set_acl(struct dentry *dentry, const char *name,
+ const void *value, size_t size,
+ int flags, int type)
+{
+ char *full_name;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ full_name = POSIX_ACL_XATTR_ACCESS;
+ break;
+ case ACL_TYPE_DEFAULT:
+ full_name = POSIX_ACL_XATTR_DEFAULT;
+ break;
+ default:
+ BUG();
+ }
+ return v9fs_xattr_set(dentry, full_name, value, size, flags);
+}
+
+
+static int v9fs_xattr_set_acl(struct dentry *dentry, const char *name,
+ const void *value, size_t size,
+ int flags, int type)
+{
+ int retval;
+ struct posix_acl *acl;
+ struct v9fs_session_info *v9ses;
+ struct inode *inode = d_inode(dentry);
+
+ if (strcmp(name, "") != 0)
+ return -EINVAL;
+
+ v9ses = v9fs_dentry2v9ses(dentry);
+ /*
+ * set the attribute on the remote. Without even looking at the
+ * xattr value. We leave it to the server to validate
+ */
+ if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
+ return v9fs_remote_set_acl(dentry, name,
+ value, size, flags, type);
+
+ if (S_ISLNK(inode->i_mode))
+ return -EOPNOTSUPP;
+ if (!inode_owner_or_capable(inode))
+ return -EPERM;
+ if (value) {
+ /* update the cached acl value */
+ acl = posix_acl_from_xattr(&init_user_ns, value, size);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ else if (acl) {
+ retval = posix_acl_valid(acl);
+ if (retval)
+ goto err_out;
+ }
+ } else
+ acl = NULL;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ name = POSIX_ACL_XATTR_ACCESS;
+ if (acl) {
+ umode_t mode = inode->i_mode;
+ retval = posix_acl_equiv_mode(acl, &mode);
+ if (retval < 0)
+ goto err_out;
+ else {
+ struct iattr iattr;
+ if (retval == 0) {
+ /*
+ * ACL can be represented
+ * by the mode bits. So don't
+ * update ACL.
+ */
+ acl = NULL;
+ value = NULL;
+ size = 0;
+ }
+ /* Updte the mode bits */
+ iattr.ia_mode = ((mode & S_IALLUGO) |
+ (inode->i_mode & ~S_IALLUGO));
+ iattr.ia_valid = ATTR_MODE;
+ /* FIXME should we update ctime ?
+ * What is the following setxattr update the
+ * mode ?
+ */
+ v9fs_vfs_setattr_dotl(dentry, &iattr);
+ }
+ }
+ break;
+ case ACL_TYPE_DEFAULT:
+ name = POSIX_ACL_XATTR_DEFAULT;
+ if (!S_ISDIR(inode->i_mode)) {
+ retval = acl ? -EINVAL : 0;
+ goto err_out;
+ }
+ break;
+ default:
+ BUG();
+ }
+ retval = v9fs_xattr_set(dentry, name, value, size, flags);
+ if (!retval)
+ set_cached_acl(inode, type, acl);
+err_out:
+ posix_acl_release(acl);
+ return retval;
+}
+
+const struct xattr_handler v9fs_xattr_acl_access_handler = {
+ .prefix = POSIX_ACL_XATTR_ACCESS,
+ .flags = ACL_TYPE_ACCESS,
+ .get = v9fs_xattr_get_acl,
+ .set = v9fs_xattr_set_acl,
+};
+
+const struct xattr_handler v9fs_xattr_acl_default_handler = {
+ .prefix = POSIX_ACL_XATTR_DEFAULT,
+ .flags = ACL_TYPE_DEFAULT,
+ .get = v9fs_xattr_get_acl,
+ .set = v9fs_xattr_set_acl,
+};
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