| 1 | /* |
| 2 | * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. |
| 3 | * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. |
| 4 | * |
| 5 | * This copyrighted material is made available to anyone wishing to use, |
| 6 | * modify, copy, or redistribute it subject to the terms and conditions |
| 7 | * of the GNU General Public License version 2. |
| 8 | */ |
| 9 | |
| 10 | #include <linux/sched.h> |
| 11 | #include <linux/slab.h> |
| 12 | #include <linux/spinlock.h> |
| 13 | #include <linux/completion.h> |
| 14 | #include <linux/buffer_head.h> |
| 15 | #include <linux/xattr.h> |
| 16 | #include <linux/posix_acl.h> |
| 17 | #include <linux/posix_acl_xattr.h> |
| 18 | #include <linux/gfs2_ondisk.h> |
| 19 | |
| 20 | #include "gfs2.h" |
| 21 | #include "incore.h" |
| 22 | #include "acl.h" |
| 23 | #include "xattr.h" |
| 24 | #include "glock.h" |
| 25 | #include "inode.h" |
| 26 | #include "meta_io.h" |
| 27 | #include "rgrp.h" |
| 28 | #include "trans.h" |
| 29 | #include "util.h" |
| 30 | |
| 31 | static const char *gfs2_acl_name(int type) |
| 32 | { |
| 33 | switch (type) { |
| 34 | case ACL_TYPE_ACCESS: |
| 35 | return XATTR_POSIX_ACL_ACCESS; |
| 36 | case ACL_TYPE_DEFAULT: |
| 37 | return XATTR_POSIX_ACL_DEFAULT; |
| 38 | } |
| 39 | return NULL; |
| 40 | } |
| 41 | |
| 42 | static struct posix_acl *__gfs2_get_acl(struct inode *inode, int type) |
| 43 | { |
| 44 | struct gfs2_inode *ip = GFS2_I(inode); |
| 45 | struct posix_acl *acl; |
| 46 | const char *name; |
| 47 | char *data; |
| 48 | int len; |
| 49 | |
| 50 | if (!ip->i_eattr) |
| 51 | return NULL; |
| 52 | |
| 53 | name = gfs2_acl_name(type); |
| 54 | len = gfs2_xattr_acl_get(ip, name, &data); |
| 55 | if (len <= 0) |
| 56 | return ERR_PTR(len); |
| 57 | acl = posix_acl_from_xattr(&init_user_ns, data, len); |
| 58 | kfree(data); |
| 59 | return acl; |
| 60 | } |
| 61 | |
| 62 | struct posix_acl *gfs2_get_acl(struct inode *inode, int type) |
| 63 | { |
| 64 | struct gfs2_inode *ip = GFS2_I(inode); |
| 65 | struct gfs2_holder gh; |
| 66 | bool need_unlock = false; |
| 67 | struct posix_acl *acl; |
| 68 | |
| 69 | if (!gfs2_glock_is_locked_by_me(ip->i_gl)) { |
| 70 | int ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, |
| 71 | LM_FLAG_ANY, &gh); |
| 72 | if (ret) |
| 73 | return ERR_PTR(ret); |
| 74 | need_unlock = true; |
| 75 | } |
| 76 | acl = __gfs2_get_acl(inode, type); |
| 77 | if (need_unlock) |
| 78 | gfs2_glock_dq_uninit(&gh); |
| 79 | return acl; |
| 80 | } |
| 81 | |
| 82 | int __gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type) |
| 83 | { |
| 84 | int error; |
| 85 | int len; |
| 86 | char *data; |
| 87 | const char *name = gfs2_acl_name(type); |
| 88 | |
| 89 | if (acl && acl->a_count > GFS2_ACL_MAX_ENTRIES(GFS2_SB(inode))) |
| 90 | return -E2BIG; |
| 91 | |
| 92 | if (type == ACL_TYPE_ACCESS) { |
| 93 | umode_t mode = inode->i_mode; |
| 94 | |
| 95 | error = posix_acl_equiv_mode(acl, &mode); |
| 96 | if (error < 0) |
| 97 | return error; |
| 98 | |
| 99 | if (error == 0) |
| 100 | acl = NULL; |
| 101 | |
| 102 | if (mode != inode->i_mode) { |
| 103 | inode->i_mode = mode; |
| 104 | mark_inode_dirty(inode); |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | if (acl) { |
| 109 | len = posix_acl_to_xattr(&init_user_ns, acl, NULL, 0); |
| 110 | if (len == 0) |
| 111 | return 0; |
| 112 | data = kmalloc(len, GFP_NOFS); |
| 113 | if (data == NULL) |
| 114 | return -ENOMEM; |
| 115 | error = posix_acl_to_xattr(&init_user_ns, acl, data, len); |
| 116 | if (error < 0) |
| 117 | goto out; |
| 118 | } else { |
| 119 | data = NULL; |
| 120 | len = 0; |
| 121 | } |
| 122 | |
| 123 | error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS); |
| 124 | if (error) |
| 125 | goto out; |
| 126 | set_cached_acl(inode, type, acl); |
| 127 | out: |
| 128 | kfree(data); |
| 129 | return error; |
| 130 | } |
| 131 | |
| 132 | int gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type) |
| 133 | { |
| 134 | struct gfs2_inode *ip = GFS2_I(inode); |
| 135 | struct gfs2_holder gh; |
| 136 | bool need_unlock = false; |
| 137 | int ret; |
| 138 | |
| 139 | ret = gfs2_rsqa_alloc(ip); |
| 140 | if (ret) |
| 141 | return ret; |
| 142 | |
| 143 | if (!gfs2_glock_is_locked_by_me(ip->i_gl)) { |
| 144 | ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); |
| 145 | if (ret) |
| 146 | return ret; |
| 147 | need_unlock = true; |
| 148 | } |
| 149 | ret = __gfs2_set_acl(inode, acl, type); |
| 150 | if (need_unlock) |
| 151 | gfs2_glock_dq_uninit(&gh); |
| 152 | return ret; |
| 153 | } |