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, size = 0; 94 const char *name = NULL; 95 char *value = NULL; 96 struct iattr newattrs; 97 struct inode *inode = d_inode(dentry); 98 struct timespec64 old_ctime = inode_get_ctime(inode); 99 umode_t new_mode = inode->i_mode, old_mode = inode->i_mode; 100 101 if (ceph_snap(inode) != CEPH_NOSNAP) { 102 ret = -EROFS; 103 goto out; 104 } 105 106 switch (type) { 107 case ACL_TYPE_ACCESS: 108 name = XATTR_NAME_POSIX_ACL_ACCESS; 109 if (acl) { 110 ret = posix_acl_update_mode(idmap, inode, 111 &new_mode, &acl); 112 if (ret) 113 goto out; 114 } 115 break; 116 case ACL_TYPE_DEFAULT: 117 if (!S_ISDIR(inode->i_mode)) { 118 ret = acl ? -EINVAL : 0; 119 goto out; 120 } 121 name = XATTR_NAME_POSIX_ACL_DEFAULT; 122 break; 123 default: 124 ret = -EINVAL; 125 goto out; 126 } 127 128 if (acl) { 129 size = posix_acl_xattr_size(acl->a_count); 130 value = kmalloc(size, GFP_NOFS); 131 if (!value) { 132 ret = -ENOMEM; 133 goto out; 134 } 135 136 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size); 137 if (ret < 0) 138 goto out_free; 139 } 140 141 if (new_mode != old_mode) { 142 newattrs.ia_ctime = current_time(inode); 143 newattrs.ia_mode = new_mode; 144 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; 145 ret = __ceph_setattr(idmap, inode, &newattrs, NULL); 146 if (ret) 147 goto out_free; 148 } 149 150 ret = __ceph_setxattr(inode, name, value, size, 0); 151 if (ret) { 152 if (new_mode != old_mode) { 153 newattrs.ia_ctime = old_ctime; 154 newattrs.ia_mode = old_mode; 155 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; 156 __ceph_setattr(idmap, inode, &newattrs, NULL); 157 } 158 goto out_free; 159 } 160 161 ceph_set_cached_acl(inode, type, acl); 162 163 out_free: 164 kfree(value); 165 out: 166 return ret; 167 } 168 169 int ceph_pre_init_acls(struct inode *dir, umode_t *mode, 170 struct ceph_acl_sec_ctx *as_ctx) 171 { 172 struct posix_acl *acl, *default_acl; 173 size_t val_size1 = 0, val_size2 = 0; 174 struct ceph_pagelist *pagelist = NULL; 175 void *tmp_buf = NULL; 176 int err; 177 178 err = posix_acl_create(dir, mode, &default_acl, &acl); 179 if (err) 180 return err; 181 182 if (acl) { 183 err = posix_acl_equiv_mode(acl, mode); 184 if (err < 0) 185 goto out_err; 186 if (err == 0) { 187 posix_acl_release(acl); 188 acl = NULL; 189 } 190 } 191 192 if (!default_acl && !acl) 193 return 0; 194 195 if (acl) 196 val_size1 = posix_acl_xattr_size(acl->a_count); 197 if (default_acl) 198 val_size2 = posix_acl_xattr_size(default_acl->a_count); 199 200 err = -ENOMEM; 201 tmp_buf = kmalloc(max(val_size1, val_size2), GFP_KERNEL); 202 if (!tmp_buf) 203 goto out_err; 204 pagelist = ceph_pagelist_alloc(GFP_KERNEL); 205 if (!pagelist) 206 goto out_err; 207 208 err = ceph_pagelist_reserve(pagelist, PAGE_SIZE); 209 if (err) 210 goto out_err; 211 212 ceph_pagelist_encode_32(pagelist, acl && default_acl ? 2 : 1); 213 214 if (acl) { 215 size_t len = strlen(XATTR_NAME_POSIX_ACL_ACCESS); 216 err = ceph_pagelist_reserve(pagelist, len + val_size1 + 8); 217 if (err) 218 goto out_err; 219 ceph_pagelist_encode_string(pagelist, XATTR_NAME_POSIX_ACL_ACCESS, 220 len); 221 err = posix_acl_to_xattr(&init_user_ns, acl, 222 tmp_buf, val_size1); 223 if (err < 0) 224 goto out_err; 225 ceph_pagelist_encode_32(pagelist, val_size1); 226 ceph_pagelist_append(pagelist, tmp_buf, val_size1); 227 } 228 if (default_acl) { 229 size_t len = strlen(XATTR_NAME_POSIX_ACL_DEFAULT); 230 err = ceph_pagelist_reserve(pagelist, len + val_size2 + 8); 231 if (err) 232 goto out_err; 233 ceph_pagelist_encode_string(pagelist, 234 XATTR_NAME_POSIX_ACL_DEFAULT, len); 235 err = posix_acl_to_xattr(&init_user_ns, default_acl, 236 tmp_buf, val_size2); 237 if (err < 0) 238 goto out_err; 239 ceph_pagelist_encode_32(pagelist, val_size2); 240 ceph_pagelist_append(pagelist, tmp_buf, val_size2); 241 } 242 243 kfree(tmp_buf); 244 245 as_ctx->acl = acl; 246 as_ctx->default_acl = default_acl; 247 as_ctx->pagelist = pagelist; 248 return 0; 249 250 out_err: 251 posix_acl_release(acl); 252 posix_acl_release(default_acl); 253 kfree(tmp_buf); 254 if (pagelist) 255 ceph_pagelist_release(pagelist); 256 return err; 257 } 258 259 void ceph_init_inode_acls(struct inode *inode, struct ceph_acl_sec_ctx *as_ctx) 260 { 261 if (!inode) 262 return; 263 ceph_set_cached_acl(inode, ACL_TYPE_ACCESS, as_ctx->acl); 264 ceph_set_cached_acl(inode, ACL_TYPE_DEFAULT, as_ctx->default_acl); 265 } 266