linux/fs/f2fs/acl.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * fs/f2fs/acl.c
   4 *
   5 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   6 *             http://www.samsung.com/
   7 *
   8 * Portions of this code from linux/fs/ext2/acl.c
   9 *
  10 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
  11 */
  12#include <linux/f2fs_fs.h>
  13#include "f2fs.h"
  14#include "xattr.h"
  15#include "acl.h"
  16
  17static inline size_t f2fs_acl_size(int count)
  18{
  19        if (count <= 4) {
  20                return sizeof(struct f2fs_acl_header) +
  21                        count * sizeof(struct f2fs_acl_entry_short);
  22        } else {
  23                return sizeof(struct f2fs_acl_header) +
  24                        4 * sizeof(struct f2fs_acl_entry_short) +
  25                        (count - 4) * sizeof(struct f2fs_acl_entry);
  26        }
  27}
  28
  29static inline int f2fs_acl_count(size_t size)
  30{
  31        ssize_t s;
  32
  33        size -= sizeof(struct f2fs_acl_header);
  34        s = size - 4 * sizeof(struct f2fs_acl_entry_short);
  35        if (s < 0) {
  36                if (size % sizeof(struct f2fs_acl_entry_short))
  37                        return -1;
  38                return size / sizeof(struct f2fs_acl_entry_short);
  39        } else {
  40                if (s % sizeof(struct f2fs_acl_entry))
  41                        return -1;
  42                return s / sizeof(struct f2fs_acl_entry) + 4;
  43        }
  44}
  45
  46static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size)
  47{
  48        int i, count;
  49        struct posix_acl *acl;
  50        struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value;
  51        struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1);
  52        const char *end = value + size;
  53
  54        if (size < sizeof(struct f2fs_acl_header))
  55                return ERR_PTR(-EINVAL);
  56
  57        if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION))
  58                return ERR_PTR(-EINVAL);
  59
  60        count = f2fs_acl_count(size);
  61        if (count < 0)
  62                return ERR_PTR(-EINVAL);
  63        if (count == 0)
  64                return NULL;
  65
  66        acl = posix_acl_alloc(count, GFP_NOFS);
  67        if (!acl)
  68                return ERR_PTR(-ENOMEM);
  69
  70        for (i = 0; i < count; i++) {
  71
  72                if ((char *)entry > end)
  73                        goto fail;
  74
  75                acl->a_entries[i].e_tag  = le16_to_cpu(entry->e_tag);
  76                acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm);
  77
  78                switch (acl->a_entries[i].e_tag) {
  79                case ACL_USER_OBJ:
  80                case ACL_GROUP_OBJ:
  81                case ACL_MASK:
  82                case ACL_OTHER:
  83                        entry = (struct f2fs_acl_entry *)((char *)entry +
  84                                        sizeof(struct f2fs_acl_entry_short));
  85                        break;
  86
  87                case ACL_USER:
  88                        acl->a_entries[i].e_uid =
  89                                make_kuid(&init_user_ns,
  90                                                le32_to_cpu(entry->e_id));
  91                        entry = (struct f2fs_acl_entry *)((char *)entry +
  92                                        sizeof(struct f2fs_acl_entry));
  93                        break;
  94                case ACL_GROUP:
  95                        acl->a_entries[i].e_gid =
  96                                make_kgid(&init_user_ns,
  97                                                le32_to_cpu(entry->e_id));
  98                        entry = (struct f2fs_acl_entry *)((char *)entry +
  99                                        sizeof(struct f2fs_acl_entry));
 100                        break;
 101                default:
 102                        goto fail;
 103                }
 104        }
 105        if ((char *)entry != end)
 106                goto fail;
 107        return acl;
 108fail:
 109        posix_acl_release(acl);
 110        return ERR_PTR(-EINVAL);
 111}
 112
 113static void *f2fs_acl_to_disk(struct f2fs_sb_info *sbi,
 114                                const struct posix_acl *acl, size_t *size)
 115{
 116        struct f2fs_acl_header *f2fs_acl;
 117        struct f2fs_acl_entry *entry;
 118        int i;
 119
 120        f2fs_acl = f2fs_kmalloc(sbi, sizeof(struct f2fs_acl_header) +
 121                        acl->a_count * sizeof(struct f2fs_acl_entry),
 122                        GFP_NOFS);
 123        if (!f2fs_acl)
 124                return ERR_PTR(-ENOMEM);
 125
 126        f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION);
 127        entry = (struct f2fs_acl_entry *)(f2fs_acl + 1);
 128
 129        for (i = 0; i < acl->a_count; i++) {
 130
 131                entry->e_tag  = cpu_to_le16(acl->a_entries[i].e_tag);
 132                entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm);
 133
 134                switch (acl->a_entries[i].e_tag) {
 135                case ACL_USER:
 136                        entry->e_id = cpu_to_le32(
 137                                        from_kuid(&init_user_ns,
 138                                                acl->a_entries[i].e_uid));
 139                        entry = (struct f2fs_acl_entry *)((char *)entry +
 140                                        sizeof(struct f2fs_acl_entry));
 141                        break;
 142                case ACL_GROUP:
 143                        entry->e_id = cpu_to_le32(
 144                                        from_kgid(&init_user_ns,
 145                                                acl->a_entries[i].e_gid));
 146                        entry = (struct f2fs_acl_entry *)((char *)entry +
 147                                        sizeof(struct f2fs_acl_entry));
 148                        break;
 149                case ACL_USER_OBJ:
 150                case ACL_GROUP_OBJ:
 151                case ACL_MASK:
 152                case ACL_OTHER:
 153                        entry = (struct f2fs_acl_entry *)((char *)entry +
 154                                        sizeof(struct f2fs_acl_entry_short));
 155                        break;
 156                default:
 157                        goto fail;
 158                }
 159        }
 160        *size = f2fs_acl_size(acl->a_count);
 161        return (void *)f2fs_acl;
 162
 163fail:
 164        kfree(f2fs_acl);
 165        return ERR_PTR(-EINVAL);
 166}
 167
 168static struct posix_acl *__f2fs_get_acl(struct inode *inode, int type,
 169                                                struct page *dpage)
 170{
 171        int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
 172        void *value = NULL;
 173        struct posix_acl *acl;
 174        int retval;
 175
 176        if (type == ACL_TYPE_ACCESS)
 177                name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
 178
 179        retval = f2fs_getxattr(inode, name_index, "", NULL, 0, dpage);
 180        if (retval > 0) {
 181                value = f2fs_kmalloc(F2FS_I_SB(inode), retval, GFP_F2FS_ZERO);
 182                if (!value)
 183                        return ERR_PTR(-ENOMEM);
 184                retval = f2fs_getxattr(inode, name_index, "", value,
 185                                                        retval, dpage);
 186        }
 187
 188        if (retval > 0)
 189                acl = f2fs_acl_from_disk(value, retval);
 190        else if (retval == -ENODATA)
 191                acl = NULL;
 192        else
 193                acl = ERR_PTR(retval);
 194        kfree(value);
 195
 196        return acl;
 197}
 198
 199struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
 200{
 201        return __f2fs_get_acl(inode, type, NULL);
 202}
 203
 204static int f2fs_acl_update_mode(struct inode *inode, umode_t *mode_p,
 205                          struct posix_acl **acl)
 206{
 207        umode_t mode = inode->i_mode;
 208        int error;
 209
 210        if (is_inode_flag_set(inode, FI_ACL_MODE))
 211                mode = F2FS_I(inode)->i_acl_mode;
 212
 213        error = posix_acl_equiv_mode(*acl, &mode);
 214        if (error < 0)
 215                return error;
 216        if (error == 0)
 217                *acl = NULL;
 218        if (!in_group_p(i_gid_into_mnt(&init_user_ns, inode)) &&
 219            !capable_wrt_inode_uidgid(&init_user_ns, inode, CAP_FSETID))
 220                mode &= ~S_ISGID;
 221        *mode_p = mode;
 222        return 0;
 223}
 224
 225static int __f2fs_set_acl(struct inode *inode, int type,
 226                        struct posix_acl *acl, struct page *ipage)
 227{
 228        int name_index;
 229        void *value = NULL;
 230        size_t size = 0;
 231        int error;
 232        umode_t mode = inode->i_mode;
 233
 234        switch (type) {
 235        case ACL_TYPE_ACCESS:
 236                name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
 237                if (acl && !ipage) {
 238                        error = f2fs_acl_update_mode(inode, &mode, &acl);
 239                        if (error)
 240                                return error;
 241                        set_acl_inode(inode, mode);
 242                }
 243                break;
 244
 245        case ACL_TYPE_DEFAULT:
 246                name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
 247                if (!S_ISDIR(inode->i_mode))
 248                        return acl ? -EACCES : 0;
 249                break;
 250
 251        default:
 252                return -EINVAL;
 253        }
 254
 255        if (acl) {
 256                value = f2fs_acl_to_disk(F2FS_I_SB(inode), acl, &size);
 257                if (IS_ERR(value)) {
 258                        clear_inode_flag(inode, FI_ACL_MODE);
 259                        return PTR_ERR(value);
 260                }
 261        }
 262
 263        error = f2fs_setxattr(inode, name_index, "", value, size, ipage, 0);
 264
 265        kfree(value);
 266        if (!error)
 267                set_cached_acl(inode, type, acl);
 268
 269        clear_inode_flag(inode, FI_ACL_MODE);
 270        return error;
 271}
 272
 273int f2fs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
 274                 struct posix_acl *acl, int type)
 275{
 276        if (unlikely(f2fs_cp_error(F2FS_I_SB(inode))))
 277                return -EIO;
 278
 279        return __f2fs_set_acl(inode, type, acl, NULL);
 280}
 281
 282/*
 283 * Most part of f2fs_acl_clone, f2fs_acl_create_masq, f2fs_acl_create
 284 * are copied from posix_acl.c
 285 */
 286static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl,
 287                                                        gfp_t flags)
 288{
 289        struct posix_acl *clone = NULL;
 290
 291        if (acl) {
 292                int size = sizeof(struct posix_acl) + acl->a_count *
 293                                sizeof(struct posix_acl_entry);
 294                clone = kmemdup(acl, size, flags);
 295                if (clone)
 296                        refcount_set(&clone->a_refcount, 1);
 297        }
 298        return clone;
 299}
 300
 301static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
 302{
 303        struct posix_acl_entry *pa, *pe;
 304        struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
 305        umode_t mode = *mode_p;
 306        int not_equiv = 0;
 307
 308        /* assert(atomic_read(acl->a_refcount) == 1); */
 309
 310        FOREACH_ACL_ENTRY(pa, acl, pe) {
 311                switch (pa->e_tag) {
 312                case ACL_USER_OBJ:
 313                        pa->e_perm &= (mode >> 6) | ~S_IRWXO;
 314                        mode &= (pa->e_perm << 6) | ~S_IRWXU;
 315                        break;
 316
 317                case ACL_USER:
 318                case ACL_GROUP:
 319                        not_equiv = 1;
 320                        break;
 321
 322                case ACL_GROUP_OBJ:
 323                        group_obj = pa;
 324                        break;
 325
 326                case ACL_OTHER:
 327                        pa->e_perm &= mode | ~S_IRWXO;
 328                        mode &= pa->e_perm | ~S_IRWXO;
 329                        break;
 330
 331                case ACL_MASK:
 332                        mask_obj = pa;
 333                        not_equiv = 1;
 334                        break;
 335
 336                default:
 337                        return -EIO;
 338                }
 339        }
 340
 341        if (mask_obj) {
 342                mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
 343                mode &= (mask_obj->e_perm << 3) | ~S_IRWXG;
 344        } else {
 345                if (!group_obj)
 346                        return -EIO;
 347                group_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
 348                mode &= (group_obj->e_perm << 3) | ~S_IRWXG;
 349        }
 350
 351        *mode_p = (*mode_p & ~S_IRWXUGO) | mode;
 352        return not_equiv;
 353}
 354
 355static int f2fs_acl_create(struct inode *dir, umode_t *mode,
 356                struct posix_acl **default_acl, struct posix_acl **acl,
 357                struct page *dpage)
 358{
 359        struct posix_acl *p;
 360        struct posix_acl *clone;
 361        int ret;
 362
 363        *acl = NULL;
 364        *default_acl = NULL;
 365
 366        if (S_ISLNK(*mode) || !IS_POSIXACL(dir))
 367                return 0;
 368
 369        p = __f2fs_get_acl(dir, ACL_TYPE_DEFAULT, dpage);
 370        if (!p || p == ERR_PTR(-EOPNOTSUPP)) {
 371                *mode &= ~current_umask();
 372                return 0;
 373        }
 374        if (IS_ERR(p))
 375                return PTR_ERR(p);
 376
 377        clone = f2fs_acl_clone(p, GFP_NOFS);
 378        if (!clone) {
 379                ret = -ENOMEM;
 380                goto release_acl;
 381        }
 382
 383        ret = f2fs_acl_create_masq(clone, mode);
 384        if (ret < 0)
 385                goto release_clone;
 386
 387        if (ret == 0)
 388                posix_acl_release(clone);
 389        else
 390                *acl = clone;
 391
 392        if (!S_ISDIR(*mode))
 393                posix_acl_release(p);
 394        else
 395                *default_acl = p;
 396
 397        return 0;
 398
 399release_clone:
 400        posix_acl_release(clone);
 401release_acl:
 402        posix_acl_release(p);
 403        return ret;
 404}
 405
 406int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage,
 407                                                        struct page *dpage)
 408{
 409        struct posix_acl *default_acl = NULL, *acl = NULL;
 410        int error;
 411
 412        error = f2fs_acl_create(dir, &inode->i_mode, &default_acl, &acl, dpage);
 413        if (error)
 414                return error;
 415
 416        f2fs_mark_inode_dirty_sync(inode, true);
 417
 418        if (default_acl) {
 419                error = __f2fs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl,
 420                                       ipage);
 421                posix_acl_release(default_acl);
 422        } else {
 423                inode->i_default_acl = NULL;
 424        }
 425        if (acl) {
 426                if (!error)
 427                        error = __f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl,
 428                                               ipage);
 429                posix_acl_release(acl);
 430        } else {
 431                inode->i_acl = NULL;
 432        }
 433
 434        return error;
 435}
 436
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.