1 /* 2 * linux/fs/ceph/acl.c 3 * 4 * Copyright (C) 2013 Guangliang Zhao, <lucienchao@gmail.com> 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public 8 * License v2 as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public 16 * License along with this program; if not, write to the 17 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 18 * Boston, MA 021110-1307, USA. 19 */ 20 21 #include <linux/ceph/ceph_debug.h> 22 #include <linux/fs.h> 23 #include <linux/string.h> 24 #include <linux/xattr.h> 25 #include <linux/posix_acl_xattr.h> 26 #include <linux/posix_acl.h> 27 #include <linux/sched.h> 28 #include <linux/slab.h> 29 30 #include "super.h" 31 32 static inline void ceph_set_cached_acl(struct inode *inode, 33 int type, struct posix_acl *acl) 34 { 35 struct ceph_inode_info *ci = ceph_inode(inode); 36 37 spin_lock(&ci->i_ceph_lock); 38 if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 0)) 39 set_cached_acl(inode, type, acl); 40 spin_unlock(&ci->i_ceph_lock); 41 } 42 43 static inline struct posix_acl *ceph_get_cached_acl(struct inode *inode, 44 int type) 45 { 46 struct ceph_inode_info *ci = ceph_inode(inode); 47 struct posix_acl *acl = ACL_NOT_CACHED; 48 49 spin_lock(&ci->i_ceph_lock); 50 if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 0)) 51 acl = get_cached_acl(inode, type); 52 spin_unlock(&ci->i_ceph_lock); 53 54 return acl; 55 } 56 57 struct posix_acl *ceph_get_acl(struct inode *inode, int type) 58 { 59 int size; 60 const char *name; 61 char *value = NULL; 62 struct posix_acl *acl; 63 64 switch (type) { 65 case ACL_TYPE_ACCESS: 66 name = POSIX_ACL_XATTR_ACCESS; 67 break; 68 case ACL_TYPE_DEFAULT: 69 name = POSIX_ACL_XATTR_DEFAULT; 70 break; 71 default: 72 BUG(); 73 } 74 75 size = __ceph_getxattr(inode, name, "", 0); 76 if (size > 0) { 77 value = kzalloc(size, GFP_NOFS); 78 if (!value) 79 return ERR_PTR(-ENOMEM); 80 size = __ceph_getxattr(inode, name, value, size); 81 } 82 83 if (size > 0) 84 acl = posix_acl_from_xattr(&init_user_ns, value, size); 85 else if (size == -ERANGE || size == -ENODATA || size == 0) 86 acl = NULL; 87 else 88 acl = ERR_PTR(-EIO); 89 90 kfree(value); 91 92 if (!IS_ERR(acl)) 93 ceph_set_cached_acl(inode, type, acl); 94 95 return acl; 96 } 97 98 int ceph_set_acl(struct inode *inode, struct posix_acl *acl, int type) 99 { 100 int ret = 0, size = 0; 101 const char *name = NULL; 102 char *value = NULL; 103 struct iattr newattrs; 104 umode_t new_mode = inode->i_mode, old_mode = inode->i_mode; 105 struct dentry *dentry; 106 107 switch (type) { 108 case ACL_TYPE_ACCESS: 109 name = POSIX_ACL_XATTR_ACCESS; 110 if (acl) { 111 ret = posix_acl_equiv_mode(acl, &new_mode); 112 if (ret < 0) 113 goto out; 114 if (ret == 0) 115 acl = NULL; 116 } 117 break; 118 case ACL_TYPE_DEFAULT: 119 if (!S_ISDIR(inode->i_mode)) { 120 ret = acl ? -EINVAL : 0; 121 goto out; 122 } 123 name = POSIX_ACL_XATTR_DEFAULT; 124 break; 125 default: 126 ret = -EINVAL; 127 goto out; 128 } 129 130 if (acl) { 131 size = posix_acl_xattr_size(acl->a_count); 132 value = kmalloc(size, GFP_NOFS); 133 if (!value) { 134 ret = -ENOMEM; 135 goto out; 136 } 137 138 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size); 139 if (ret < 0) 140 goto out_free; 141 } 142 143 dentry = d_find_alias(inode); 144 if (new_mode != old_mode) { 145 newattrs.ia_mode = new_mode; 146 newattrs.ia_valid = ATTR_MODE; 147 ret = ceph_setattr(dentry, &newattrs); 148 if (ret) 149 goto out_dput; 150 } 151 152 ret = __ceph_setxattr(dentry, name, value, size, 0); 153 if (ret) { 154 if (new_mode != old_mode) { 155 newattrs.ia_mode = old_mode; 156 newattrs.ia_valid = ATTR_MODE; 157 ceph_setattr(dentry, &newattrs); 158 } 159 goto out_dput; 160 } 161 162 ceph_set_cached_acl(inode, type, acl); 163 164 out_dput: 165 dput(dentry); 166 out_free: 167 kfree(value); 168 out: 169 return ret; 170 } 171 172 int ceph_init_acl(struct dentry *dentry, struct inode *inode, struct inode *dir) 173 { 174 struct posix_acl *default_acl, *acl; 175 umode_t new_mode = inode->i_mode; 176 int error; 177 178 error = posix_acl_create(dir, &new_mode, &default_acl, &acl); 179 if (error) 180 return error; 181 182 if (!default_acl && !acl) { 183 cache_no_acl(inode); 184 if (new_mode != inode->i_mode) { 185 struct iattr newattrs = { 186 .ia_mode = new_mode, 187 .ia_valid = ATTR_MODE, 188 }; 189 error = ceph_setattr(dentry, &newattrs); 190 } 191 return error; 192 } 193 194 if (default_acl) { 195 error = ceph_set_acl(inode, default_acl, ACL_TYPE_DEFAULT); 196 posix_acl_release(default_acl); 197 } 198 if (acl) { 199 if (!error) 200 error = ceph_set_acl(inode, acl, ACL_TYPE_ACCESS); 201 posix_acl_release(acl); 202 } 203 return error; 204 } 205