From 85ff872d3f4a62d076d698bd1fa15ca2a4d7c100 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Tue, 28 Sep 2010 00:27:39 +0530 Subject: fs/9p: Implement POSIX ACL permission checking function The ACL value is fetched as a part of inode initialization from the server and the permission checking function use the cached value of the ACL Signed-off-by: Aneesh Kumar K.V Signed-off-by: Venkateswararao Jujjuri Signed-off-by: Eric Van Hensbergen --- fs/9p/acl.c | 96 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 96 insertions(+) create mode 100644 fs/9p/acl.c (limited to 'fs/9p/acl.c') diff --git a/fs/9p/acl.c b/fs/9p/acl.c new file mode 100644 index 00000000000..a8c013615a2 --- /dev/null +++ b/fs/9p/acl.c @@ -0,0 +1,96 @@ +/* + * Copyright IBM Corporation, 2010 + * Author Aneesh Kumar K.V + * + * 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 +#include +#include +#include +#include +#include +#include "xattr.h" +#include "acl.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(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; + + /* 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); + posix_acl_release(dacl); + posix_acl_release(pacl); + } else + retval = -EIO; + + 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; +} + +int v9fs_check_acl(struct inode *inode, int mask) +{ + struct posix_acl *acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS); + + if (IS_ERR(acl)) + return PTR_ERR(acl); + if (acl) { + int error = posix_acl_permission(inode, acl, mask); + posix_acl_release(acl); + return error; + } + return -EAGAIN; +} -- cgit v1.2.3