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 #include "mds_client.h" 19 20 static inline void ceph_set_cached_acl(struct inode *inode, 21 int type, struct posix_acl *acl) 22 { 23 struct ceph_inode_info *ci = ceph_inode(inode); 24 25 spin_lock(&ci->i_ceph_lock); 26 if (__ceph_caps_issued_mask_metric(ci, CEPH_CAP_XATTR_SHARED, 0)) 27 set_cached_acl(inode, type, acl); 28 else 29 forget_cached_acl(inode, type); 30 spin_unlock(&ci->i_ceph_lock); 31 } 32 33 struct posix_acl *ceph_get_acl(struct inode *inode, int type, bool rcu) 34 { 35 struct ceph_client *cl = ceph_inode_to_client(inode); 36 int size; 37 unsigned int retry_cnt = 0; 38 const char *name; 39 char *value = NULL; 40 struct posix_acl *acl; 41 42 if (rcu) 43 return ERR_PTR(-ECHILD); 44 45 switch (type) { 46 case ACL_TYPE_ACCESS: 47 name = XATTR_NAME_POSIX_ACL_ACCESS; 48 break; 49 case ACL_TYPE_DEFAULT: 50 name = XATTR_NAME_POSIX_ACL_DEFAULT; 51 break; 52 default: 53 BUG(); 54 } 55 56 retry: 57 size = __ceph_getxattr(inode, name, "", 0); 58 if (size > 0) { 59 value = kzalloc(size, GFP_NOFS); 60 if (!value) 61 return ERR_PTR(-ENOMEM); 62 size = __ceph_getxattr(inode, name, value, size); 63 } 64 65 if (size == -ERANGE && retry_cnt < 10) { 66 retry_cnt++; 67 kfree(value); 68 value = NULL; 69 goto retry; 70 } 71 72 if (size > 0) { 73 acl = posix_acl_from_xattr(&init_user_ns, value, size); 74 } else if (size == -ENODATA || size == 0) { 75 acl = NULL; 76 } else { 77 pr_err_ratelimited_client(cl, "%llx.%llx failed, err=%d\n", 78 ceph_vinop(inode), size); 79 acl = ERR_PTR(-EIO); 80 } 81 82 kfree(value); 83 84 if (!IS_ERR(acl)) 85 ceph_set_cached_acl(inode, type, acl); 86 87 return acl; 88 } 89 90 int ceph_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 91 struct posix_acl *acl, int type) 92 { 93 int ret = 0; 94 size_t size = 0; 95 const char *name = NULL; 96 char *value = NULL; 97 struct iattr newattrs; 98 struct inode *inode = d_inode(dentry); 99 struct timespec64 old_ctime = inode_get_ctime(inode); 100 umode_t new_mode = inode->i_mode, old_mode = inode->i_mode; 101 102 if (ceph_snap(inode) != CEPH_NOSNAP) { 103 ret = -EROFS; 104 goto out; 105 } 106 107 switch (type) { 108 case ACL_TYPE_ACCESS: 109 name = XATTR_NAME_POSIX_ACL_ACCESS; 110 if (acl) { 111 ret = posix_acl_update_mode(idmap, inode, 112 &new_mode, &acl); 113 if (ret) 114 goto out; 115 } 116 break; 117 case ACL_TYPE_DEFAULT: 118 if (!S_ISDIR(inode->i_mode)) { 119 ret = acl ? -EINVAL : 0; 120 goto out; 121 } 122 name = XATTR_NAME_POSIX_ACL_DEFAULT; 123 break; 124 default: 125 ret = -EINVAL; 126 goto out; 127 } 128 129 if (acl) { 130 value = posix_acl_to_xattr(&init_user_ns, acl, &size, GFP_NOFS); 131 if (!value) { 132 ret = -ENOMEM; 133 goto out; 134 } 135 } 136 137 if (new_mode != old_mode) { 138 newattrs.ia_ctime = current_time(inode); 139 newattrs.ia_mode = new_mode; 140 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; 141 ret = __ceph_setattr(idmap, inode, &newattrs, NULL); 142 if (ret) 143 goto out_free; 144 } 145 146 ret = __ceph_setxattr(inode, name, value, size, 0); 147 if (ret) { 148 if (new_mode != old_mode) { 149 newattrs.ia_ctime = old_ctime; 150 newattrs.ia_mode = old_mode; 151 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; 152 __ceph_setattr(idmap, inode, &newattrs, NULL); 153 } 154 goto out_free; 155 } 156 157 ceph_set_cached_acl(inode, type, acl); 158 159 out_free: 160 kfree(value); 161 out: 162 return ret; 163 } 164 165 int ceph_pre_init_acls(struct inode *dir, umode_t *mode, 166 struct ceph_acl_sec_ctx *as_ctx) 167 { 168 struct posix_acl *acl, *default_acl; 169 size_t val_size1 = 0, val_size2 = 0; 170 struct ceph_pagelist *pagelist = NULL; 171 void *tmp_buf1 = NULL, *tmp_buf2 = NULL; 172 int err; 173 174 err = posix_acl_create(dir, mode, &default_acl, &acl); 175 if (err) 176 return err; 177 178 if (acl) { 179 err = posix_acl_equiv_mode(acl, mode); 180 if (err < 0) 181 goto out_err; 182 if (err == 0) { 183 posix_acl_release(acl); 184 acl = NULL; 185 } 186 } 187 188 if (!default_acl && !acl) 189 return 0; 190 191 err = -ENOMEM; 192 pagelist = ceph_pagelist_alloc(GFP_KERNEL); 193 if (!pagelist) 194 goto out_err; 195 196 err = ceph_pagelist_reserve(pagelist, PAGE_SIZE); 197 if (err) 198 goto out_err; 199 200 ceph_pagelist_encode_32(pagelist, acl && default_acl ? 2 : 1); 201 202 if (acl) { 203 size_t len = strlen(XATTR_NAME_POSIX_ACL_ACCESS); 204 205 err = -ENOMEM; 206 tmp_buf1 = posix_acl_to_xattr(&init_user_ns, acl, 207 &val_size1, GFP_KERNEL); 208 if (!tmp_buf1) 209 goto out_err; 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 ceph_pagelist_encode_32(pagelist, val_size1); 216 ceph_pagelist_append(pagelist, tmp_buf1, val_size1); 217 } 218 if (default_acl) { 219 size_t len = strlen(XATTR_NAME_POSIX_ACL_DEFAULT); 220 221 err = -ENOMEM; 222 tmp_buf2 = posix_acl_to_xattr(&init_user_ns, default_acl, 223 &val_size2, GFP_KERNEL); 224 if (!tmp_buf2) 225 goto out_err; 226 err = ceph_pagelist_reserve(pagelist, len + val_size2 + 8); 227 if (err) 228 goto out_err; 229 ceph_pagelist_encode_string(pagelist, 230 XATTR_NAME_POSIX_ACL_DEFAULT, len); 231 ceph_pagelist_encode_32(pagelist, val_size2); 232 ceph_pagelist_append(pagelist, tmp_buf2, val_size2); 233 } 234 235 kfree(tmp_buf1); 236 kfree(tmp_buf2); 237 238 as_ctx->acl = acl; 239 as_ctx->default_acl = default_acl; 240 as_ctx->pagelist = pagelist; 241 return 0; 242 243 out_err: 244 posix_acl_release(acl); 245 posix_acl_release(default_acl); 246 kfree(tmp_buf1); 247 kfree(tmp_buf2); 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