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