| 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 | } |