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 inode *inode, struct posix_acl *acl, int type) 86 { 87 int ret = 0, size = 0; 88 const char *name = NULL; 89 char *value = NULL; 90 struct iattr newattrs; 91 struct timespec64 old_ctime = inode->i_ctime; 92 umode_t new_mode = inode->i_mode, old_mode = inode->i_mode; 93 94 if (ceph_snap(inode) != CEPH_NOSNAP) { 95 ret = -EROFS; 96 goto out; 97 } 98 99 switch (type) { 100 case ACL_TYPE_ACCESS: 101 name = XATTR_NAME_POSIX_ACL_ACCESS; 102 if (acl) { 103 ret = posix_acl_update_mode(inode, &new_mode, &acl); 104 if (ret) 105 goto out; 106 } 107 break; 108 case ACL_TYPE_DEFAULT: 109 if (!S_ISDIR(inode->i_mode)) { 110 ret = acl ? -EINVAL : 0; 111 goto out; 112 } 113 name = XATTR_NAME_POSIX_ACL_DEFAULT; 114 break; 115 default: 116 ret = -EINVAL; 117 goto out; 118 } 119 120 if (acl) { 121 size = posix_acl_xattr_size(acl->a_count); 122 value = kmalloc(size, GFP_NOFS); 123 if (!value) { 124 ret = -ENOMEM; 125 goto out; 126 } 127 128 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size); 129 if (ret < 0) 130 goto out_free; 131 } 132 133 if (new_mode != old_mode) { 134 newattrs.ia_ctime = current_time(inode); 135 newattrs.ia_mode = new_mode; 136 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; 137 ret = __ceph_setattr(inode, &newattrs); 138 if (ret) 139 goto out_free; 140 } 141 142 ret = __ceph_setxattr(inode, name, value, size, 0); 143 if (ret) { 144 if (new_mode != old_mode) { 145 newattrs.ia_ctime = old_ctime; 146 newattrs.ia_mode = old_mode; 147 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; 148 __ceph_setattr(inode, &newattrs); 149 } 150 goto out_free; 151 } 152 153 ceph_set_cached_acl(inode, type, acl); 154 155 out_free: 156 kfree(value); 157 out: 158 return ret; 159 } 160 161 int ceph_pre_init_acls(struct inode *dir, umode_t *mode, 162 struct ceph_acl_sec_ctx *as_ctx) 163 { 164 struct posix_acl *acl, *default_acl; 165 size_t val_size1 = 0, val_size2 = 0; 166 struct ceph_pagelist *pagelist = NULL; 167 void *tmp_buf = NULL; 168 int err; 169 170 err = posix_acl_create(dir, mode, &default_acl, &acl); 171 if (err) 172 return err; 173 174 if (acl) { 175 err = posix_acl_equiv_mode(acl, mode); 176 if (err < 0) 177 goto out_err; 178 if (err == 0) { 179 posix_acl_release(acl); 180 acl = NULL; 181 } 182 } 183 184 if (!default_acl && !acl) 185 return 0; 186 187 if (acl) 188 val_size1 = posix_acl_xattr_size(acl->a_count); 189 if (default_acl) 190 val_size2 = posix_acl_xattr_size(default_acl->a_count); 191 192 err = -ENOMEM; 193 tmp_buf = kmalloc(max(val_size1, val_size2), GFP_KERNEL); 194 if (!tmp_buf) 195 goto out_err; 196 pagelist = ceph_pagelist_alloc(GFP_KERNEL); 197 if (!pagelist) 198 goto out_err; 199 200 err = ceph_pagelist_reserve(pagelist, PAGE_SIZE); 201 if (err) 202 goto out_err; 203 204 ceph_pagelist_encode_32(pagelist, acl && default_acl ? 2 : 1); 205 206 if (acl) { 207 size_t len = strlen(XATTR_NAME_POSIX_ACL_ACCESS); 208 err = ceph_pagelist_reserve(pagelist, len + val_size1 + 8); 209 if (err) 210 goto out_err; 211 ceph_pagelist_encode_string(pagelist, XATTR_NAME_POSIX_ACL_ACCESS, 212 len); 213 err = posix_acl_to_xattr(&init_user_ns, acl, 214 tmp_buf, val_size1); 215 if (err < 0) 216 goto out_err; 217 ceph_pagelist_encode_32(pagelist, val_size1); 218 ceph_pagelist_append(pagelist, tmp_buf, val_size1); 219 } 220 if (default_acl) { 221 size_t len = strlen(XATTR_NAME_POSIX_ACL_DEFAULT); 222 err = ceph_pagelist_reserve(pagelist, len + val_size2 + 8); 223 if (err) 224 goto out_err; 225 ceph_pagelist_encode_string(pagelist, 226 XATTR_NAME_POSIX_ACL_DEFAULT, len); 227 err = posix_acl_to_xattr(&init_user_ns, default_acl, 228 tmp_buf, val_size2); 229 if (err < 0) 230 goto out_err; 231 ceph_pagelist_encode_32(pagelist, val_size2); 232 ceph_pagelist_append(pagelist, tmp_buf, val_size2); 233 } 234 235 kfree(tmp_buf); 236 237 as_ctx->acl = acl; 238 as_ctx->default_acl = default_acl; 239 as_ctx->pagelist = pagelist; 240 return 0; 241 242 out_err: 243 posix_acl_release(acl); 244 posix_acl_release(default_acl); 245 kfree(tmp_buf); 246 if (pagelist) 247 ceph_pagelist_release(pagelist); 248 return err; 249 } 250 251 void ceph_init_inode_acls(struct inode *inode, struct ceph_acl_sec_ctx *as_ctx) 252 { 253 if (!inode) 254 return; 255 ceph_set_cached_acl(inode, ACL_TYPE_ACCESS, as_ctx->acl); 256 ceph_set_cached_acl(inode, ACL_TYPE_DEFAULT, as_ctx->default_acl); 257 } 258