/* * 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, XATTR_NAME_POSIX_ACL_DEFAULT); pacl = __v9fs_get_acl(fid, XATTR_NAME_POSIX_ACL_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(is_uncached_acl(acl)); return acl; } struct posix_acl *v9fs_iop_get_acl(struct inode *inode, int type, bool rcu) { struct v9fs_session_info *v9ses; if (rcu) return ERR_PTR(-ECHILD); 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 = XATTR_NAME_POSIX_ACL_ACCESS; break; case ACL_TYPE_DEFAULT: name = XATTR_NAME_POSIX_ACL_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_xattr_get_acl(const struct xattr_handler *handler, struct dentry *dentry, struct inode *inode, const char *name, void *buffer, size_t size) { struct v9fs_session_info *v9ses; struct posix_acl *acl; int error; 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_xattr_get(dentry, handler->name, buffer, size); acl = v9fs_get_cached_acl(inode, handler->flags); 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_xattr_set_acl(const struct xattr_handler *handler, struct user_namespace *mnt_userns, struct dentry *dentry, struct inode *inode, const char *name, const void *value, size_t size, int flags) { int retval; struct posix_acl *acl; struct v9fs_session_info *v9ses; 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_xattr_set(dentry, handler->name, value, size, flags); if (S_ISLNK(inode->i_mode)) return -EOPNOTSUPP; if (!inode_owner_or_capable(&init_user_ns, 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(inode->i_sb->s_user_ns, acl); if (retval) goto err_out; } } else acl = NULL; switch (handler->flags) { case ACL_TYPE_ACCESS: if (acl) { struct iattr iattr = { 0 }; struct posix_acl *old_acl = acl; retval = posix_acl_update_mode(&init_user_ns, inode, &iattr.ia_mode, &acl); if (retval) goto err_out; if (!acl) { /* * ACL can be represented * by the mode bits. So don't * update ACL. */ posix_acl_release(old_acl); value = NULL; size = 0; } iattr.ia_valid = ATTR_MODE; /* FIXME should we update ctime ? * What is the following setxattr update the * mode ? */ v9fs_vfs_setattr_dotl(&init_user_ns, dentry, &iattr); } break; case ACL_TYPE_DEFAULT: if (!S_ISDIR(inode->i_mode)) { retval = acl ? -EINVAL : 0; goto err_out; } break; default: BUG(); } retval = v9fs_xattr_set(dentry, handler->name, value, size, flags); if (!retval) set_cached_acl(inode, handler->flags, acl); err_out: posix_acl_release(acl); return retval; } const struct xattr_handler v9fs_xattr_acl_access_handler = { .name = XATTR_NAME_POSIX_ACL_ACCESS, .flags = ACL_TYPE_ACCESS, .get = v9fs_xattr_get_acl, .set = v9fs_xattr_set_acl, }; const struct xattr_handler v9fs_xattr_acl_default_handler = { .name = XATTR_NAME_POSIX_ACL_DEFAULT, .flags = ACL_TYPE_DEFAULT, .get = v9fs_xattr_get_acl, .set = v9fs_xattr_set_acl, };