fs/bcachefs/fs-ioctl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #ifndef NO_BCACHEFS_FS
   3
   4 #include "bcachefs.h"
   5 #include "chardev.h"
   6 #include "dirent.h"
   7 #include "fs.h"
   8 #include "fs-common.h"
   9 #include "fs-ioctl.h"
  10 #include "quota.h"
  11
  12 #include <linux/compat.h>
  13 #include <linux/fsnotify.h>
  14 #include <linux/mount.h>
  15 #include <linux/namei.h>
  16 #include <linux/security.h>
  17 #include <linux/writeback.h>
  18
  19 #define FS_IOC_GOINGDOWN             _IOR('X', 125, __u32)
  20 #define FSOP_GOING_FLAGS_DEFAULT        0x0     /* going down */
  21 #define FSOP_GOING_FLAGS_LOGFLUSH       0x1     /* flush log but not data */
  22 #define FSOP_GOING_FLAGS_NOLOGFLUSH     0x2     /* don't flush log nor data */
  23
  24 struct flags_set {
  25         unsigned                mask;
  26         unsigned                flags;
  27
  28         unsigned                projid;
  29
  30         bool                    set_projinherit;
  31         bool                    projinherit;
  32 };
  33
  34 static int bch2_inode_flags_set(struct btree_trans *trans,
  35                                 struct bch_inode_info *inode,
  36                                 struct bch_inode_unpacked *bi,
  37                                 void *p)
  38 {
  39         struct bch_fs *c = inode->v.i_sb->s_fs_info;
  40         /*
  41          * We're relying on btree locking here for exclusion with other ioctl
  42          * calls - use the flags in the btree (@bi), not inode->i_flags:
  43          */
  44         struct flags_set *s = p;
  45         unsigned newflags = s->flags;
  46         unsigned oldflags = bi->bi_flags & s->mask;
  47
  48         if (((newflags ^ oldflags) & (BCH_INODE_append|BCH_INODE_immutable)) &&
  49             !capable(CAP_LINUX_IMMUTABLE))
  50                 return -EPERM;
  51
  52         if (!S_ISREG(bi->bi_mode) &&
  53             !S_ISDIR(bi->bi_mode) &&
  54             (newflags & (BCH_INODE_nodump|BCH_INODE_noatime)) != newflags)
  55                 return -EINVAL;
  56
  57         if (s->set_projinherit) {
  58                 bi->bi_fields_set &= ~(1 << Inode_opt_project);
  59                 bi->bi_fields_set |= ((int) s->projinherit << Inode_opt_project);
  60         }
  61
  62         bi->bi_flags &= ~s->mask;
  63         bi->bi_flags |= newflags;
  64
  65         bi->bi_ctime = timespec_to_bch2_time(c, current_time(&inode->v));
  66         return 0;
  67 }
  68
  69 static int bch2_ioc_getflags(struct bch_inode_info *inode, int __user *arg)
  70 {
  71         unsigned flags = map_flags(bch_flags_to_uflags, inode->ei_inode.bi_flags);
  72
  73         return put_user(flags, arg);
  74 }
  75
  76 static int bch2_ioc_setflags(struct bch_fs *c,
  77                              struct file *file,
  78                              struct bch_inode_info *inode,
  79                              void __user *arg)
  80 {
  81         struct flags_set s = { .mask = map_defined(bch_flags_to_uflags) };
  82         unsigned uflags;
  83         int ret;
  84
  85         if (get_user(uflags, (int __user *) arg))
  86                 return -EFAULT;
  87
  88         s.flags = map_flags_rev(bch_flags_to_uflags, uflags);
  89         if (uflags)
  90                 return -EOPNOTSUPP;
  91
  92         ret = mnt_want_write_file(file);
  93         if (ret)
  94                 return ret;
  95
  96         inode_lock(&inode->v);
  97         if (!inode_owner_or_capable(file_mnt_idmap(file), &inode->v)) {
  98                 ret = -EACCES;
  99                 goto setflags_out;
 100         }
 101
 102         mutex_lock(&inode->ei_update_lock);
 103         ret   = bch2_subvol_is_ro(c, inode->ei_inum.subvol) ?:
 104                 bch2_write_inode(c, inode, bch2_inode_flags_set, &s,
 105                                ATTR_CTIME);
 106         mutex_unlock(&inode->ei_update_lock);
 107
 108 setflags_out:
 109         inode_unlock(&inode->v);
 110         mnt_drop_write_file(file);
 111         return ret;
 112 }
 113
 114 static int bch2_ioc_fsgetxattr(struct bch_inode_info *inode,
 115                                struct fsxattr __user *arg)
 116 {
 117         struct fsxattr fa = { 0 };
 118
 119         fa.fsx_xflags = map_flags(bch_flags_to_xflags, inode->ei_inode.bi_flags);
 120
 121         if (inode->ei_inode.bi_fields_set & (1 << Inode_opt_project))
 122                 fa.fsx_xflags |= FS_XFLAG_PROJINHERIT;
 123
 124         fa.fsx_projid = inode->ei_qid.q[QTYP_PRJ];
 125
 126         if (copy_to_user(arg, &fa, sizeof(fa)))
 127                 return -EFAULT;
 128
 129         return 0;
 130 }
 131
 132 static int fssetxattr_inode_update_fn(struct btree_trans *trans,
 133                                       struct bch_inode_info *inode,
 134                                       struct bch_inode_unpacked *bi,
 135                                       void *p)
 136 {
 137         struct flags_set *s = p;
 138
 139         if (s->projid != bi->bi_project) {
 140                 bi->bi_fields_set |= 1U << Inode_opt_project;
 141                 bi->bi_project = s->projid;
 142         }
 143
 144         return bch2_inode_flags_set(trans, inode, bi, p);
 145 }
 146
 147 static int bch2_ioc_fssetxattr(struct bch_fs *c,
 148                                struct file *file,
 149                                struct bch_inode_info *inode,
 150                                struct fsxattr __user *arg)
 151 {
 152         struct flags_set s = { .mask = map_defined(bch_flags_to_xflags) };
 153         struct fsxattr fa;
 154         int ret;
 155
 156         if (copy_from_user(&fa, arg, sizeof(fa)))
 157                 return -EFAULT;
 158
 159         s.set_projinherit = true;
 160         s.projinherit = (fa.fsx_xflags & FS_XFLAG_PROJINHERIT) != 0;
 161         fa.fsx_xflags &= ~FS_XFLAG_PROJINHERIT;
 162
 163         s.flags = map_flags_rev(bch_flags_to_xflags, fa.fsx_xflags);
 164         if (fa.fsx_xflags)
 165                 return -EOPNOTSUPP;
 166
 167         if (fa.fsx_projid >= U32_MAX)
 168                 return -EINVAL;
 169
 170         /*
 171          * inode fields accessible via the xattr interface are stored with a +1
 172          * bias, so that 0 means unset:
 173          */
 174         s.projid = fa.fsx_projid + 1;
 175
 176         ret = mnt_want_write_file(file);
 177         if (ret)
 178                 return ret;
 179
 180         inode_lock(&inode->v);
 181         if (!inode_owner_or_capable(file_mnt_idmap(file), &inode->v)) {
 182                 ret = -EACCES;
 183                 goto err;
 184         }
 185
 186         mutex_lock(&inode->ei_update_lock);
 187         ret   = bch2_subvol_is_ro(c, inode->ei_inum.subvol) ?:
 188                 bch2_set_projid(c, inode, fa.fsx_projid) ?:
 189                 bch2_write_inode(c, inode, fssetxattr_inode_update_fn, &s,
 190                                ATTR_CTIME);
 191         mutex_unlock(&inode->ei_update_lock);
 192 err:
 193         inode_unlock(&inode->v);
 194         mnt_drop_write_file(file);
 195         return ret;
 196 }
 197
 198 static int bch2_reinherit_attrs_fn(struct btree_trans *trans,
 199                                    struct bch_inode_info *inode,
 200                                    struct bch_inode_unpacked *bi,
 201                                    void *p)
 202 {
 203         struct bch_inode_info *dir = p;
 204
 205         return !bch2_reinherit_attrs(bi, &dir->ei_inode);
 206 }
 207
 208 static int bch2_ioc_reinherit_attrs(struct bch_fs *c,
 209                                     struct file *file,
 210                                     struct bch_inode_info *src,
 211                                     const char __user *name)
 212 {
 213         struct bch_hash_info hash = bch2_hash_info_init(c, &src->ei_inode);
 214         struct bch_inode_info *dst;
 215         struct inode *vinode = NULL;
 216         char *kname = NULL;
 217         struct qstr qstr;
 218         int ret = 0;
 219         subvol_inum inum;
 220
 221         kname = kmalloc(BCH_NAME_MAX + 1, GFP_KERNEL);
 222         if (!kname)
 223                 return -ENOMEM;
 224
 225         ret = strncpy_from_user(kname, name, BCH_NAME_MAX);
 226         if (unlikely(ret < 0))
 227                 goto err1;
 228
 229         qstr.len        = ret;
 230         qstr.name       = kname;
 231
 232         ret = bch2_dirent_lookup(c, inode_inum(src), &hash, &qstr, &inum);
 233         if (ret)
 234                 goto err1;
 235
 236         vinode = bch2_vfs_inode_get(c, inum);
 237         ret = PTR_ERR_OR_ZERO(vinode);
 238         if (ret)
 239                 goto err1;
 240
 241         dst = to_bch_ei(vinode);
 242
 243         ret = mnt_want_write_file(file);
 244         if (ret)
 245                 goto err2;
 246
 247         bch2_lock_inodes(INODE_UPDATE_LOCK, src, dst);
 248
 249         if (inode_attr_changing(src, dst, Inode_opt_project)) {
 250                 ret = bch2_fs_quota_transfer(c, dst,
 251                                              src->ei_qid,
 252                                              1 << QTYP_PRJ,
 253                                              KEY_TYPE_QUOTA_PREALLOC);
 254                 if (ret)
 255                         goto err3;
 256         }
 257
 258         ret = bch2_write_inode(c, dst, bch2_reinherit_attrs_fn, src, 0);
 259 err3:
 260         bch2_unlock_inodes(INODE_UPDATE_LOCK, src, dst);
 261
 262         /* return true if we did work */
 263         if (ret >= 0)
 264                 ret = !ret;
 265
 266         mnt_drop_write_file(file);
 267 err2:
 268         iput(vinode);
 269 err1:
 270         kfree(kname);
 271
 272         return ret;
 273 }
 274
 275 static int bch2_ioc_getversion(struct bch_inode_info *inode, u32 __user *arg)
 276 {
 277         return put_user(inode->v.i_generation, arg);
 278 }
 279
 280 static int bch2_ioc_getlabel(struct bch_fs *c, char __user *user_label)
 281 {
 282         int ret;
 283         size_t len;
 284         char label[BCH_SB_LABEL_SIZE];
 285
 286         BUILD_BUG_ON(BCH_SB_LABEL_SIZE >= FSLABEL_MAX);
 287
 288         mutex_lock(&c->sb_lock);
 289         memcpy(label, c->disk_sb.sb->label, BCH_SB_LABEL_SIZE);
 290         mutex_unlock(&c->sb_lock);
 291
 292         len = strnlen(label, BCH_SB_LABEL_SIZE);
 293         if (len == BCH_SB_LABEL_SIZE) {
 294                 bch_warn(c,
 295                         "label is too long, return the first %zu bytes",
 296                         --len);
 297         }
 298
 299         ret = copy_to_user(user_label, label, len);
 300
 301         return ret ? -EFAULT : 0;
 302 }
 303
 304 static int bch2_ioc_setlabel(struct bch_fs *c,
 305                              struct file *file,
 306                              struct bch_inode_info *inode,
 307                              const char __user *user_label)
 308 {
 309         int ret;
 310         char label[BCH_SB_LABEL_SIZE];
 311
 312         if (!capable(CAP_SYS_ADMIN))
 313                 return -EPERM;
 314
 315         if (copy_from_user(label, user_label, sizeof(label)))
 316                 return -EFAULT;
 317
 318         if (strnlen(label, BCH_SB_LABEL_SIZE) == BCH_SB_LABEL_SIZE) {
 319                 bch_err(c,
 320                         "unable to set label with more than %d bytes",
 321                         BCH_SB_LABEL_SIZE - 1);
 322                 return -EINVAL;
 323         }
 324
 325         ret = mnt_want_write_file(file);
 326         if (ret)
 327                 return ret;
 328
 329         mutex_lock(&c->sb_lock);
 330         strscpy(c->disk_sb.sb->label, label, BCH_SB_LABEL_SIZE);
 331         ret = bch2_write_super(c);
 332         mutex_unlock(&c->sb_lock);
 333
 334         mnt_drop_write_file(file);
 335         return ret;
 336 }
 337
 338 static int bch2_ioc_goingdown(struct bch_fs *c, u32 __user *arg)
 339 {
 340         u32 flags;
 341         int ret = 0;
 342
 343         if (!capable(CAP_SYS_ADMIN))
 344                 return -EPERM;
 345
 346         if (get_user(flags, arg))
 347                 return -EFAULT;
 348
 349         bch_notice(c, "shutdown by ioctl type %u", flags);
 350
 351         switch (flags) {
 352         case FSOP_GOING_FLAGS_DEFAULT:
 353                 ret = bdev_freeze(c->vfs_sb->s_bdev);
 354                 if (ret)
 355                         break;
 356                 bch2_journal_flush(&c->journal);
 357                 bch2_fs_emergency_read_only(c);
 358                 bdev_thaw(c->vfs_sb->s_bdev);
 359                 break;
 360         case FSOP_GOING_FLAGS_LOGFLUSH:
 361                 bch2_journal_flush(&c->journal);
 362                 fallthrough;
 363         case FSOP_GOING_FLAGS_NOLOGFLUSH:
 364                 bch2_fs_emergency_read_only(c);
 365                 break;
 366         default:
 367                 ret = -EINVAL;
 368                 break;
 369         }
 370
 371         return ret;
 372 }
 373
 374 static long bch2_ioctl_subvolume_create(struct bch_fs *c, struct file *filp,
 375                                         struct bch_ioctl_subvolume arg)
 376 {
 377         struct inode *dir;
 378         struct bch_inode_info *inode;
 379         struct user_namespace *s_user_ns;
 380         struct dentry *dst_dentry;
 381         struct path src_path, dst_path;
 382         int how = LOOKUP_FOLLOW;
 383         int error;
 384         subvol_inum snapshot_src = { 0 };
 385         unsigned lookup_flags = 0;
 386         unsigned create_flags = BCH_CREATE_SUBVOL;
 387
 388         if (arg.flags & ~(BCH_SUBVOL_SNAPSHOT_CREATE|
 389                           BCH_SUBVOL_SNAPSHOT_RO))
 390                 return -EINVAL;
 391
 392         if (!(arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE) &&
 393             (arg.src_ptr ||
 394              (arg.flags & BCH_SUBVOL_SNAPSHOT_RO)))
 395                 return -EINVAL;
 396
 397         if (arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE)
 398                 create_flags |= BCH_CREATE_SNAPSHOT;
 399
 400         if (arg.flags & BCH_SUBVOL_SNAPSHOT_RO)
 401                 create_flags |= BCH_CREATE_SNAPSHOT_RO;
 402
 403         if (arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE) {
 404                 /* sync_inodes_sb enforce s_umount is locked */
 405                 down_read(&c->vfs_sb->s_umount);
 406                 sync_inodes_sb(c->vfs_sb);
 407                 up_read(&c->vfs_sb->s_umount);
 408         }
 409 retry:
 410         if (arg.src_ptr) {
 411                 error = user_path_at(arg.dirfd,
 412                                 (const char __user *)(unsigned long)arg.src_ptr,
 413                                 how, &src_path);
 414                 if (error)
 415                         goto err1;
 416
 417                 if (src_path.dentry->d_sb->s_fs_info != c) {
 418                         path_put(&src_path);
 419                         error = -EXDEV;
 420                         goto err1;
 421                 }
 422
 423                 snapshot_src = inode_inum(to_bch_ei(src_path.dentry->d_inode));
 424         }
 425
 426         dst_dentry = user_path_create(arg.dirfd,
 427                         (const char __user *)(unsigned long)arg.dst_ptr,
 428                         &dst_path, lookup_flags);
 429         error = PTR_ERR_OR_ZERO(dst_dentry);
 430         if (error)
 431                 goto err2;
 432
 433         if (dst_dentry->d_sb->s_fs_info != c) {
 434                 error = -EXDEV;
 435                 goto err3;
 436         }
 437
 438         if (dst_dentry->d_inode) {
 439                 error = -BCH_ERR_EEXIST_subvolume_create;
 440                 goto err3;
 441         }
 442
 443         dir = dst_path.dentry->d_inode;
 444         if (IS_DEADDIR(dir)) {
 445                 error = -BCH_ERR_ENOENT_directory_dead;
 446                 goto err3;
 447         }
 448
 449         s_user_ns = dir->i_sb->s_user_ns;
 450         if (!kuid_has_mapping(s_user_ns, current_fsuid()) ||
 451             !kgid_has_mapping(s_user_ns, current_fsgid())) {
 452                 error = -EOVERFLOW;
 453                 goto err3;
 454         }
 455
 456         error = inode_permission(file_mnt_idmap(filp),
 457                                  dir, MAY_WRITE | MAY_EXEC);
 458         if (error)
 459                 goto err3;
 460
 461         if (!IS_POSIXACL(dir))
 462                 arg.mode &= ~current_umask();
 463
 464         error = security_path_mkdir(&dst_path, dst_dentry, arg.mode);
 465         if (error)
 466                 goto err3;
 467
 468         if ((arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE) &&
 469             !arg.src_ptr)
 470                 snapshot_src.subvol = inode_inum(to_bch_ei(dir)).subvol;
 471
 472         down_write(&c->snapshot_create_lock);
 473         inode = __bch2_create(file_mnt_idmap(filp), to_bch_ei(dir),
 474                               dst_dentry, arg.mode|S_IFDIR,
 475                               0, snapshot_src, create_flags);
 476         up_write(&c->snapshot_create_lock);
 477
 478         error = PTR_ERR_OR_ZERO(inode);
 479         if (error)
 480                 goto err3;
 481
 482         d_instantiate(dst_dentry, &inode->v);
 483         fsnotify_mkdir(dir, dst_dentry);
 484 err3:
 485         done_path_create(&dst_path, dst_dentry);
 486 err2:
 487         if (arg.src_ptr)
 488                 path_put(&src_path);
 489
 490         if (retry_estale(error, lookup_flags)) {
 491                 lookup_flags |= LOOKUP_REVAL;
 492                 goto retry;
 493         }
 494 err1:
 495         return error;
 496 }
 497
 498 static long bch2_ioctl_subvolume_destroy(struct bch_fs *c, struct file *filp,
 499                                 struct bch_ioctl_subvolume arg)
 500 {
 501         const char __user *name = (void __user *)(unsigned long)arg.dst_ptr;
 502         struct path path;
 503         struct inode *dir;
 504         struct dentry *victim;
 505         int ret = 0;
 506
 507         if (arg.flags)
 508                 return -EINVAL;
 509
 510         victim = user_path_locked_at(arg.dirfd, name, &path);
 511         if (IS_ERR(victim))
 512                 return PTR_ERR(victim);
 513
 514         dir = d_inode(path.dentry);
 515         if (victim->d_sb->s_fs_info != c) {
 516                 ret = -EXDEV;
 517                 goto err;
 518         }
 519         if (!d_is_positive(victim)) {
 520                 ret = -ENOENT;
 521                 goto err;
 522         }
 523         ret = __bch2_unlink(dir, victim, true);
 524         if (!ret) {
 525                 fsnotify_rmdir(dir, victim);
 526                 d_delete(victim);
 527         }
 528 err:
 529         inode_unlock(dir);
 530         dput(victim);
 531         path_put(&path);
 532         return ret;
 533 }
 534
 535 long bch2_fs_file_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 536 {
 537         struct bch_inode_info *inode = file_bch_inode(file);
 538         struct bch_fs *c = inode->v.i_sb->s_fs_info;
 539         long ret;
 540
 541         switch (cmd) {
 542         case FS_IOC_GETFLAGS:
 543                 ret = bch2_ioc_getflags(inode, (int __user *) arg);
 544                 break;
 545
 546         case FS_IOC_SETFLAGS:
 547                 ret = bch2_ioc_setflags(c, file, inode, (int __user *) arg);
 548                 break;
 549
 550         case FS_IOC_FSGETXATTR:
 551                 ret = bch2_ioc_fsgetxattr(inode, (void __user *) arg);
 552                 break;
 553
 554         case FS_IOC_FSSETXATTR:
 555                 ret = bch2_ioc_fssetxattr(c, file, inode,
 556                                           (void __user *) arg);
 557                 break;
 558
 559         case BCHFS_IOC_REINHERIT_ATTRS:
 560                 ret = bch2_ioc_reinherit_attrs(c, file, inode,
 561                                                (void __user *) arg);
 562                 break;
 563
 564         case FS_IOC_GETVERSION:
 565                 ret = bch2_ioc_getversion(inode, (u32 __user *) arg);
 566                 break;
 567
 568         case FS_IOC_SETVERSION:
 569                 ret = -ENOTTY;
 570                 break;
 571
 572         case FS_IOC_GETFSLABEL:
 573                 ret = bch2_ioc_getlabel(c, (void __user *) arg);
 574                 break;
 575
 576         case FS_IOC_SETFSLABEL:
 577                 ret = bch2_ioc_setlabel(c, file, inode, (const void __user *) arg);
 578                 break;
 579
 580         case FS_IOC_GOINGDOWN:
 581                 ret = bch2_ioc_goingdown(c, (u32 __user *) arg);
 582                 break;
 583
 584         case BCH_IOCTL_SUBVOLUME_CREATE: {
 585                 struct bch_ioctl_subvolume i;
 586
 587                 ret = copy_from_user(&i, (void __user *) arg, sizeof(i))
 588                         ? -EFAULT
 589                         : bch2_ioctl_subvolume_create(c, file, i);
 590                 break;
 591         }
 592
 593         case BCH_IOCTL_SUBVOLUME_DESTROY: {
 594                 struct bch_ioctl_subvolume i;
 595
 596                 ret = copy_from_user(&i, (void __user *) arg, sizeof(i))
 597                         ? -EFAULT
 598                         : bch2_ioctl_subvolume_destroy(c, file, i);
 599                 break;
 600         }
 601
 602         default:
 603                 ret = bch2_fs_ioctl(c, cmd, (void __user *) arg);
 604                 break;
 605         }
 606
 607         return bch2_err_class(ret);
 608 }
 609
 610 #ifdef CONFIG_COMPAT
 611 long bch2_compat_fs_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 612 {
 613         /* These are just misnamed, they actually get/put from/to user an int */
 614         switch (cmd) {
 615         case FS_IOC32_GETFLAGS:
 616                 cmd = FS_IOC_GETFLAGS;
 617                 break;
 618         case FS_IOC32_SETFLAGS:
 619                 cmd = FS_IOC_SETFLAGS;
 620                 break;
 621         case FS_IOC32_GETVERSION:
 622                 cmd = FS_IOC_GETVERSION;
 623                 break;
 624         case FS_IOC_GETFSLABEL:
 625         case FS_IOC_SETFSLABEL:
 626                 break;
 627         default:
 628                 return -ENOIOCTLCMD;
 629         }
 630         return bch2_fs_file_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 631 }
 632 #endif
 633
 634 #endif /* NO_BCACHEFS_FS */