Aneesh Kumar K.V | 85ff872 | 2010-09-28 00:27:39 +0530 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright IBM Corporation, 2010 |
| 3 | * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of version 2.1 of the GNU Lesser General Public License |
| 7 | * as published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope that it would be useful, but |
| 10 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| 12 | * |
| 13 | */ |
| 14 | |
| 15 | #include <linux/module.h> |
| 16 | #include <linux/fs.h> |
| 17 | #include <net/9p/9p.h> |
| 18 | #include <net/9p/client.h> |
| 19 | #include <linux/slab.h> |
| 20 | #include <linux/posix_acl_xattr.h> |
| 21 | #include "xattr.h" |
| 22 | #include "acl.h" |
| 23 | |
| 24 | static struct posix_acl *__v9fs_get_acl(struct p9_fid *fid, char *name) |
| 25 | { |
| 26 | ssize_t size; |
| 27 | void *value = NULL; |
| 28 | struct posix_acl *acl = NULL;; |
| 29 | |
| 30 | size = v9fs_fid_xattr_get(fid, name, NULL, 0); |
| 31 | if (size > 0) { |
| 32 | value = kzalloc(size, GFP_NOFS); |
| 33 | if (!value) |
| 34 | return ERR_PTR(-ENOMEM); |
| 35 | size = v9fs_fid_xattr_get(fid, name, value, size); |
| 36 | if (size > 0) { |
| 37 | acl = posix_acl_from_xattr(value, size); |
| 38 | if (IS_ERR(acl)) |
| 39 | goto err_out; |
| 40 | } |
| 41 | } else if (size == -ENODATA || size == 0 || |
| 42 | size == -ENOSYS || size == -EOPNOTSUPP) { |
| 43 | acl = NULL; |
| 44 | } else |
| 45 | acl = ERR_PTR(-EIO); |
| 46 | |
| 47 | err_out: |
| 48 | kfree(value); |
| 49 | return acl; |
| 50 | } |
| 51 | |
| 52 | int v9fs_get_acl(struct inode *inode, struct p9_fid *fid) |
| 53 | { |
| 54 | int retval = 0; |
| 55 | struct posix_acl *pacl, *dacl; |
| 56 | |
| 57 | /* get the default/access acl values and cache them */ |
| 58 | dacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_DEFAULT); |
| 59 | pacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_ACCESS); |
| 60 | |
| 61 | if (!IS_ERR(dacl) && !IS_ERR(pacl)) { |
| 62 | set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl); |
| 63 | set_cached_acl(inode, ACL_TYPE_ACCESS, pacl); |
| 64 | posix_acl_release(dacl); |
| 65 | posix_acl_release(pacl); |
| 66 | } else |
| 67 | retval = -EIO; |
| 68 | |
| 69 | return retval; |
| 70 | } |
| 71 | |
| 72 | static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type) |
| 73 | { |
| 74 | struct posix_acl *acl; |
| 75 | /* |
| 76 | * 9p Always cache the acl value when |
| 77 | * instantiating the inode (v9fs_inode_from_fid) |
| 78 | */ |
| 79 | acl = get_cached_acl(inode, type); |
| 80 | BUG_ON(acl == ACL_NOT_CACHED); |
| 81 | return acl; |
| 82 | } |
| 83 | |
| 84 | int v9fs_check_acl(struct inode *inode, int mask) |
| 85 | { |
| 86 | struct posix_acl *acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS); |
| 87 | |
| 88 | if (IS_ERR(acl)) |
| 89 | return PTR_ERR(acl); |
| 90 | if (acl) { |
| 91 | int error = posix_acl_permission(inode, acl, mask); |
| 92 | posix_acl_release(acl); |
| 93 | return error; |
| 94 | } |
| 95 | return -EAGAIN; |
| 96 | } |