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 inode *inode, 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 timespec64 old_ctime = inode->i_ctime; 96 umode_t new_mode = inode->i_mode, old_mode = inode->i_mode; 97 98 if (ceph_snap(inode) != CEPH_NOSNAP) { 99 ret = -EROFS; 100 goto out; 101 } 102 103 switch (type) { 104 case ACL_TYPE_ACCESS: 105 name = XATTR_NAME_POSIX_ACL_ACCESS; 106 if (acl) { 107 ret = posix_acl_update_mode(&init_user_ns, inode, 108 &new_mode, &acl); 109 if (ret) 110 goto out; 111 } 112 break; 113 case ACL_TYPE_DEFAULT: 114 if (!S_ISDIR(inode->i_mode)) { 115 ret = acl ? -EINVAL : 0; 116 goto out; 117 } 118 name = XATTR_NAME_POSIX_ACL_DEFAULT; 119 break; 120 default: 121 ret = -EINVAL; 122 goto out; 123 } 124 125 if (acl) { 126 size = posix_acl_xattr_size(acl->a_count); 127 value = kmalloc(size, GFP_NOFS); 128 if (!value) { 129 ret = -ENOMEM; 130 goto out; 131 } 132 133 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size); 134 if (ret < 0) 135 goto out_free; 136 } 137 138 if (new_mode != old_mode) { 139 newattrs.ia_ctime = current_time(inode); 140 newattrs.ia_mode = new_mode; 141 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; 142 ret = __ceph_setattr(inode, &newattrs); 143 if (ret) 144 goto out_free; 145 } 146 147 ret = __ceph_setxattr(inode, name, value, size, 0); 148 if (ret) { 149 if (new_mode != old_mode) { 150 newattrs.ia_ctime = old_ctime; 151 newattrs.ia_mode = old_mode; 152 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; 153 __ceph_setattr(inode, &newattrs); 154 } 155 goto out_free; 156 } 157 158 ceph_set_cached_acl(inode, type, acl); 159 160 out_free: 161 kfree(value); 162 out: 163 return ret; 164 } 165 166 int ceph_pre_init_acls(struct inode *dir, umode_t *mode, 167 struct ceph_acl_sec_ctx *as_ctx) 168 { 169 struct posix_acl *acl, *default_acl; 170 size_t val_size1 = 0, val_size2 = 0; 171 struct ceph_pagelist *pagelist = NULL; 172 void *tmp_buf = NULL; 173 int err; 174 175 err = posix_acl_create(dir, mode, &default_acl, &acl); 176 if (err) 177 return err; 178 179 if (acl) { 180 err = posix_acl_equiv_mode(acl, mode); 181 if (err < 0) 182 goto out_err; 183 if (err == 0) { 184 posix_acl_release(acl); 185 acl = NULL; 186 } 187 } 188 189 if (!default_acl && !acl) 190 return 0; 191 192 if (acl) 193 val_size1 = posix_acl_xattr_size(acl->a_count); 194 if (default_acl) 195 val_size2 = posix_acl_xattr_size(default_acl->a_count); 196 197 err = -ENOMEM; 198 tmp_buf = kmalloc(max(val_size1, val_size2), GFP_KERNEL); 199 if (!tmp_buf) 200 goto out_err; 201 pagelist = ceph_pagelist_alloc(GFP_KERNEL); 202 if (!pagelist) 203 goto out_err; 204 205 err = ceph_pagelist_reserve(pagelist, PAGE_SIZE); 206 if (err) 207 goto out_err; 208 209 ceph_pagelist_encode_32(pagelist, acl && default_acl ? 2 : 1); 210 211 if (acl) { 212 size_t len = strlen(XATTR_NAME_POSIX_ACL_ACCESS); 213 err = ceph_pagelist_reserve(pagelist, len + val_size1 + 8); 214 if (err) 215 goto out_err; 216 ceph_pagelist_encode_string(pagelist, XATTR_NAME_POSIX_ACL_ACCESS, 217 len); 218 err = posix_acl_to_xattr(&init_user_ns, acl, 219 tmp_buf, val_size1); 220 if (err < 0) 221 goto out_err; 222 ceph_pagelist_encode_32(pagelist, val_size1); 223 ceph_pagelist_append(pagelist, tmp_buf, val_size1); 224 } 225 if (default_acl) { 226 size_t len = strlen(XATTR_NAME_POSIX_ACL_DEFAULT); 227 err = ceph_pagelist_reserve(pagelist, len + val_size2 + 8); 228 if (err) 229 goto out_err; 230 ceph_pagelist_encode_string(pagelist, 231 XATTR_NAME_POSIX_ACL_DEFAULT, len); 232 err = posix_acl_to_xattr(&init_user_ns, default_acl, 233 tmp_buf, val_size2); 234 if (err < 0) 235 goto out_err; 236 ceph_pagelist_encode_32(pagelist, val_size2); 237 ceph_pagelist_append(pagelist, tmp_buf, val_size2); 238 } 239 240 kfree(tmp_buf); 241 242 as_ctx->acl = acl; 243 as_ctx->default_acl = default_acl; 244 as_ctx->pagelist = pagelist; 245 return 0; 246 247 out_err: 248 posix_acl_release(acl); 249 posix_acl_release(default_acl); 250 kfree(tmp_buf); 251 if (pagelist) 252 ceph_pagelist_release(pagelist); 253 return err; 254 } 255 256 void ceph_init_inode_acls(struct inode *inode, struct ceph_acl_sec_ctx *as_ctx) 257 { 258 if (!inode) 259 return; 260 ceph_set_cached_acl(inode, ACL_TYPE_ACCESS, as_ctx->acl); 261 ceph_set_cached_acl(inode, ACL_TYPE_DEFAULT, as_ctx->default_acl); 262 } 263