1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/fs/ceph/acl.c 4 * 5 * Copyright (C) 2013 Guangliang Zhao, <lucienchao@gmail.com> 6 */ 7 8 #include <linux/ceph/ceph_debug.h> 9 #include <linux/fs.h> 10 #include <linux/string.h> 11 #include <linux/xattr.h> 12 #include <linux/posix_acl_xattr.h> 13 #include <linux/posix_acl.h> 14 #include <linux/sched.h> 15 #include <linux/slab.h> 16 17 #include "super.h" 18 19 static inline void ceph_set_cached_acl(struct inode *inode, 20 int type, struct posix_acl *acl) 21 { 22 struct ceph_inode_info *ci = ceph_inode(inode); 23 24 spin_lock(&ci->i_ceph_lock); 25 if (__ceph_caps_issued_mask_metric(ci, CEPH_CAP_XATTR_SHARED, 0)) 26 set_cached_acl(inode, type, acl); 27 else 28 forget_cached_acl(inode, type); 29 spin_unlock(&ci->i_ceph_lock); 30 } 31 32 struct posix_acl *ceph_get_acl(struct inode *inode, int type, bool rcu) 33 { 34 int size; 35 unsigned int retry_cnt = 0; 36 const char *name; 37 char *value = NULL; 38 struct posix_acl *acl; 39 40 if (rcu) 41 return ERR_PTR(-ECHILD); 42 43 switch (type) { 44 case ACL_TYPE_ACCESS: 45 name = XATTR_NAME_POSIX_ACL_ACCESS; 46 break; 47 case ACL_TYPE_DEFAULT: 48 name = XATTR_NAME_POSIX_ACL_DEFAULT; 49 break; 50 default: 51 BUG(); 52 } 53 54 retry: 55 size = __ceph_getxattr(inode, name, "", 0); 56 if (size > 0) { 57 value = kzalloc(size, GFP_NOFS); 58 if (!value) 59 return ERR_PTR(-ENOMEM); 60 size = __ceph_getxattr(inode, name, value, size); 61 } 62 63 if (size == -ERANGE && retry_cnt < 10) { 64 retry_cnt++; 65 kfree(value); 66 value = NULL; 67 goto retry; 68 } 69 70 if (size > 0) { 71 acl = posix_acl_from_xattr(&init_user_ns, value, size); 72 } else if (size == -ENODATA || size == 0) { 73 acl = NULL; 74 } else { 75 pr_err_ratelimited("get acl %llx.%llx failed, err=%d\n", 76 ceph_vinop(inode), size); 77 acl = ERR_PTR(-EIO); 78 } 79 80 kfree(value); 81 82 if (!IS_ERR(acl)) 83 ceph_set_cached_acl(inode, type, acl); 84 85 return acl; 86 } 87 88 int ceph_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry, 89 struct posix_acl *acl, int type) 90 { 91 int ret = 0, size = 0; 92 const char *name = NULL; 93 char *value = NULL; 94 struct iattr newattrs; 95 struct inode *inode = d_inode(dentry); 96 struct timespec64 old_ctime = inode->i_ctime; 97 umode_t new_mode = inode->i_mode, old_mode = inode->i_mode; 98 99 if (ceph_snap(inode) != CEPH_NOSNAP) { 100 ret = -EROFS; 101 goto out; 102 } 103 104 switch (type) { 105 case ACL_TYPE_ACCESS: 106 name = XATTR_NAME_POSIX_ACL_ACCESS; 107 if (acl) { 108 ret = posix_acl_update_mode(&init_user_ns, inode, 109 &new_mode, &acl); 110 if (ret) 111 goto out; 112 } 113 break; 114 case ACL_TYPE_DEFAULT: 115 if (!S_ISDIR(inode->i_mode)) { 116 ret = acl ? -EINVAL : 0; 117 goto out; 118 } 119 name = XATTR_NAME_POSIX_ACL_DEFAULT; 120 break; 121 default: 122 ret = -EINVAL; 123 goto out; 124 } 125 126 if (acl) { 127 size = posix_acl_xattr_size(acl->a_count); 128 value = kmalloc(size, GFP_NOFS); 129 if (!value) { 130 ret = -ENOMEM; 131 goto out; 132 } 133 134 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size); 135 if (ret < 0) 136 goto out_free; 137 } 138 139 if (new_mode != old_mode) { 140 newattrs.ia_ctime = current_time(inode); 141 newattrs.ia_mode = new_mode; 142 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; 143 ret = __ceph_setattr(inode, &newattrs); 144 if (ret) 145 goto out_free; 146 } 147 148 ret = __ceph_setxattr(inode, name, value, size, 0); 149 if (ret) { 150 if (new_mode != old_mode) { 151 newattrs.ia_ctime = old_ctime; 152 newattrs.ia_mode = old_mode; 153 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; 154 __ceph_setattr(inode, &newattrs); 155 } 156 goto out_free; 157 } 158 159 ceph_set_cached_acl(inode, type, acl); 160 161 out_free: 162 kfree(value); 163 out: 164 return ret; 165 } 166 167 int ceph_pre_init_acls(struct inode *dir, umode_t *mode, 168 struct ceph_acl_sec_ctx *as_ctx) 169 { 170 struct posix_acl *acl, *default_acl; 171 size_t val_size1 = 0, val_size2 = 0; 172 struct ceph_pagelist *pagelist = NULL; 173 void *tmp_buf = NULL; 174 int err; 175 176 err = posix_acl_create(dir, mode, &default_acl, &acl); 177 if (err) 178 return err; 179 180 if (acl) { 181 err = posix_acl_equiv_mode(acl, mode); 182 if (err < 0) 183 goto out_err; 184 if (err == 0) { 185 posix_acl_release(acl); 186 acl = NULL; 187 } 188 } 189 190 if (!default_acl && !acl) 191 return 0; 192 193 if (acl) 194 val_size1 = posix_acl_xattr_size(acl->a_count); 195 if (default_acl) 196 val_size2 = posix_acl_xattr_size(default_acl->a_count); 197 198 err = -ENOMEM; 199 tmp_buf = kmalloc(max(val_size1, val_size2), GFP_KERNEL); 200 if (!tmp_buf) 201 goto out_err; 202 pagelist = ceph_pagelist_alloc(GFP_KERNEL); 203 if (!pagelist) 204 goto out_err; 205 206 err = ceph_pagelist_reserve(pagelist, PAGE_SIZE); 207 if (err) 208 goto out_err; 209 210 ceph_pagelist_encode_32(pagelist, acl && default_acl ? 2 : 1); 211 212 if (acl) { 213 size_t len = strlen(XATTR_NAME_POSIX_ACL_ACCESS); 214 err = ceph_pagelist_reserve(pagelist, len + val_size1 + 8); 215 if (err) 216 goto out_err; 217 ceph_pagelist_encode_string(pagelist, XATTR_NAME_POSIX_ACL_ACCESS, 218 len); 219 err = posix_acl_to_xattr(&init_user_ns, acl, 220 tmp_buf, val_size1); 221 if (err < 0) 222 goto out_err; 223 ceph_pagelist_encode_32(pagelist, val_size1); 224 ceph_pagelist_append(pagelist, tmp_buf, val_size1); 225 } 226 if (default_acl) { 227 size_t len = strlen(XATTR_NAME_POSIX_ACL_DEFAULT); 228 err = ceph_pagelist_reserve(pagelist, len + val_size2 + 8); 229 if (err) 230 goto out_err; 231 ceph_pagelist_encode_string(pagelist, 232 XATTR_NAME_POSIX_ACL_DEFAULT, len); 233 err = posix_acl_to_xattr(&init_user_ns, default_acl, 234 tmp_buf, val_size2); 235 if (err < 0) 236 goto out_err; 237 ceph_pagelist_encode_32(pagelist, val_size2); 238 ceph_pagelist_append(pagelist, tmp_buf, val_size2); 239 } 240 241 kfree(tmp_buf); 242 243 as_ctx->acl = acl; 244 as_ctx->default_acl = default_acl; 245 as_ctx->pagelist = pagelist; 246 return 0; 247 248 out_err: 249 posix_acl_release(acl); 250 posix_acl_release(default_acl); 251 kfree(tmp_buf); 252 if (pagelist) 253 ceph_pagelist_release(pagelist); 254 return err; 255 } 256 257 void ceph_init_inode_acls(struct inode *inode, struct ceph_acl_sec_ctx *as_ctx) 258 { 259 if (!inode) 260 return; 261 ceph_set_cached_acl(inode, ACL_TYPE_ACCESS, as_ctx->acl); 262 ceph_set_cached_acl(inode, ACL_TYPE_DEFAULT, as_ctx->default_acl); 263 } 264