fs/bcachefs/fs.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #ifndef NO_BCACHEFS_FS
   3
   4 #include "bcachefs.h"
   5 #include "acl.h"
   6 #include "bkey_buf.h"
   7 #include "btree_update.h"
   8 #include "buckets.h"
   9 #include "chardev.h"
  10 #include "dirent.h"
  11 #include "errcode.h"
  12 #include "extents.h"
  13 #include "fs.h"
  14 #include "fs-common.h"
  15 #include "fs-io.h"
  16 #include "fs-ioctl.h"
  17 #include "fs-io-buffered.h"
  18 #include "fs-io-direct.h"
  19 #include "fs-io-pagecache.h"
  20 #include "fsck.h"
  21 #include "inode.h"
  22 #include "io_read.h"
  23 #include "journal.h"
  24 #include "keylist.h"
  25 #include "quota.h"
  26 #include "snapshot.h"
  27 #include "super.h"
  28 #include "xattr.h"
  29
  30 #include <linux/aio.h>
  31 #include <linux/backing-dev.h>
  32 #include <linux/exportfs.h>
  33 #include <linux/fiemap.h>
  34 #include <linux/module.h>
  35 #include <linux/pagemap.h>
  36 #include <linux/posix_acl.h>
  37 #include <linux/random.h>
  38 #include <linux/seq_file.h>
  39 #include <linux/statfs.h>
  40 #include <linux/string.h>
  41 #include <linux/xattr.h>
  42
  43 static struct kmem_cache *bch2_inode_cache;
  44
  45 static void bch2_vfs_inode_init(struct btree_trans *, subvol_inum,
  46                                 struct bch_inode_info *,
  47                                 struct bch_inode_unpacked *,
  48                                 struct bch_subvolume *);
  49
  50 void bch2_inode_update_after_write(struct btree_trans *trans,
  51                                    struct bch_inode_info *inode,
  52                                    struct bch_inode_unpacked *bi,
  53                                    unsigned fields)
  54 {
  55         struct bch_fs *c = trans->c;
  56
  57         BUG_ON(bi->bi_inum != inode->v.i_ino);
  58
  59         bch2_assert_pos_locked(trans, BTREE_ID_inodes,
  60                                POS(0, bi->bi_inum),
  61                                c->opts.inodes_use_key_cache);
  62
  63         set_nlink(&inode->v, bch2_inode_nlink_get(bi));
  64         i_uid_write(&inode->v, bi->bi_uid);
  65         i_gid_write(&inode->v, bi->bi_gid);
  66         inode->v.i_mode = bi->bi_mode;
  67
  68         if (fields & ATTR_ATIME)
  69                 inode_set_atime_to_ts(&inode->v, bch2_time_to_timespec(c, bi->bi_atime));
  70         if (fields & ATTR_MTIME)
  71                 inode_set_mtime_to_ts(&inode->v, bch2_time_to_timespec(c, bi->bi_mtime));
  72         if (fields & ATTR_CTIME)
  73                 inode_set_ctime_to_ts(&inode->v, bch2_time_to_timespec(c, bi->bi_ctime));
  74
  75         inode->ei_inode         = *bi;
  76
  77         bch2_inode_flags_to_vfs(inode);
  78 }
  79
  80 int __must_check bch2_write_inode(struct bch_fs *c,
  81                                   struct bch_inode_info *inode,
  82                                   inode_set_fn set,
  83                                   void *p, unsigned fields)
  84 {
  85         struct btree_trans *trans = bch2_trans_get(c);
  86         struct btree_iter iter = { NULL };
  87         struct bch_inode_unpacked inode_u;
  88         int ret;
  89 retry:
  90         bch2_trans_begin(trans);
  91
  92         ret   = bch2_inode_peek(trans, &iter, &inode_u, inode_inum(inode),
  93                                 BTREE_ITER_intent) ?:
  94                 (set ? set(trans, inode, &inode_u, p) : 0) ?:
  95                 bch2_inode_write(trans, &iter, &inode_u) ?:
  96                 bch2_trans_commit(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc);
  97
  98         /*
  99          * the btree node lock protects inode->ei_inode, not ei_update_lock;
 100          * this is important for inode updates via bchfs_write_index_update
 101          */
 102         if (!ret)
 103                 bch2_inode_update_after_write(trans, inode, &inode_u, fields);
 104
 105         bch2_trans_iter_exit(trans, &iter);
 106
 107         if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
 108                 goto retry;
 109
 110         bch2_fs_fatal_err_on(bch2_err_matches(ret, ENOENT), c,
 111                              "%s: inode %u:%llu not found when updating",
 112                              bch2_err_str(ret),
 113                              inode_inum(inode).subvol,
 114                              inode_inum(inode).inum);
 115
 116         bch2_trans_put(trans);
 117         return ret < 0 ? ret : 0;
 118 }
 119
 120 int bch2_fs_quota_transfer(struct bch_fs *c,
 121                            struct bch_inode_info *inode,
 122                            struct bch_qid new_qid,
 123                            unsigned qtypes,
 124                            enum quota_acct_mode mode)
 125 {
 126         unsigned i;
 127         int ret;
 128
 129         qtypes &= enabled_qtypes(c);
 130
 131         for (i = 0; i < QTYP_NR; i++)
 132                 if (new_qid.q[i] == inode->ei_qid.q[i])
 133                         qtypes &= ~(1U << i);
 134
 135         if (!qtypes)
 136                 return 0;
 137
 138         mutex_lock(&inode->ei_quota_lock);
 139
 140         ret = bch2_quota_transfer(c, qtypes, new_qid,
 141                                   inode->ei_qid,
 142                                   inode->v.i_blocks +
 143                                   inode->ei_quota_reserved,
 144                                   mode);
 145         if (!ret)
 146                 for (i = 0; i < QTYP_NR; i++)
 147                         if (qtypes & (1 << i))
 148                                 inode->ei_qid.q[i] = new_qid.q[i];
 149
 150         mutex_unlock(&inode->ei_quota_lock);
 151
 152         return ret;
 153 }
 154
 155 static int bch2_iget5_test(struct inode *vinode, void *p)
 156 {
 157         struct bch_inode_info *inode = to_bch_ei(vinode);
 158         subvol_inum *inum = p;
 159
 160         return inode->ei_subvol == inum->subvol &&
 161                 inode->ei_inode.bi_inum == inum->inum;
 162 }
 163
 164 static int bch2_iget5_set(struct inode *vinode, void *p)
 165 {
 166         struct bch_inode_info *inode = to_bch_ei(vinode);
 167         subvol_inum *inum = p;
 168
 169         inode->v.i_ino          = inum->inum;
 170         inode->ei_subvol        = inum->subvol;
 171         inode->ei_inode.bi_inum = inum->inum;
 172         return 0;
 173 }
 174
 175 static unsigned bch2_inode_hash(subvol_inum inum)
 176 {
 177         return jhash_3words(inum.subvol, inum.inum >> 32, inum.inum, JHASH_INITVAL);
 178 }
 179
 180 static struct bch_inode_info *bch2_inode_insert(struct bch_fs *c, struct bch_inode_info *inode)
 181 {
 182         subvol_inum inum = inode_inum(inode);
 183         struct bch_inode_info *old = to_bch_ei(inode_insert5(&inode->v,
 184                                       bch2_inode_hash(inum),
 185                                       bch2_iget5_test,
 186                                       bch2_iget5_set,
 187                                       &inum));
 188         BUG_ON(!old);
 189
 190         if (unlikely(old != inode)) {
 191                 __destroy_inode(&inode->v);
 192                 kmem_cache_free(bch2_inode_cache, inode);
 193                 inode = old;
 194         } else {
 195                 mutex_lock(&c->vfs_inodes_lock);
 196                 list_add(&inode->ei_vfs_inode_list, &c->vfs_inodes_list);
 197                 mutex_unlock(&c->vfs_inodes_lock);
 198                 /*
 199                  * we really don't want insert_inode_locked2() to be setting
 200                  * I_NEW...
 201                  */
 202                 unlock_new_inode(&inode->v);
 203         }
 204
 205         return inode;
 206 }
 207
 208 #define memalloc_flags_do(_flags, _do)                                          \
 209 ({                                                                              \
 210         unsigned _saved_flags = memalloc_flags_save(_flags);                    \
 211         typeof(_do) _ret = _do;                                                 \
 212         memalloc_noreclaim_restore(_saved_flags);                               \
 213         _ret;                                                                   \
 214 })
 215
 216 static struct inode *bch2_alloc_inode(struct super_block *sb)
 217 {
 218         BUG();
 219 }
 220
 221 static struct bch_inode_info *__bch2_new_inode(struct bch_fs *c)
 222 {
 223         struct bch_inode_info *inode = kmem_cache_alloc(bch2_inode_cache, GFP_NOFS);
 224         if (!inode)
 225                 return NULL;
 226
 227         inode_init_once(&inode->v);
 228         mutex_init(&inode->ei_update_lock);
 229         two_state_lock_init(&inode->ei_pagecache_lock);
 230         INIT_LIST_HEAD(&inode->ei_vfs_inode_list);
 231         mutex_init(&inode->ei_quota_lock);
 232         inode->v.i_state = 0;
 233
 234         if (unlikely(inode_init_always(c->vfs_sb, &inode->v))) {
 235                 kmem_cache_free(bch2_inode_cache, inode);
 236                 return NULL;
 237         }
 238
 239         return inode;
 240 }
 241
 242 /*
 243  * Allocate a new inode, dropping/retaking btree locks if necessary:
 244  */
 245 static struct bch_inode_info *bch2_new_inode(struct btree_trans *trans)
 246 {
 247         struct bch_inode_info *inode =
 248                 memalloc_flags_do(PF_MEMALLOC_NORECLAIM|PF_MEMALLOC_NOWARN,
 249                                   __bch2_new_inode(trans->c));
 250
 251         if (unlikely(!inode)) {
 252                 int ret = drop_locks_do(trans, (inode = __bch2_new_inode(trans->c)) ? 0 : -ENOMEM);
 253                 if (ret && inode) {
 254                         __destroy_inode(&inode->v);
 255                         kmem_cache_free(bch2_inode_cache, inode);
 256                 }
 257                 if (ret)
 258                         return ERR_PTR(ret);
 259         }
 260
 261         return inode;
 262 }
 263
 264 struct inode *bch2_vfs_inode_get(struct bch_fs *c, subvol_inum inum)
 265 {
 266         struct bch_inode_info *inode =
 267                 to_bch_ei(ilookup5_nowait(c->vfs_sb,
 268                                           bch2_inode_hash(inum),
 269                                           bch2_iget5_test,
 270                                           &inum));
 271         if (inode)
 272                 return &inode->v;
 273
 274         struct btree_trans *trans = bch2_trans_get(c);
 275
 276         struct bch_inode_unpacked inode_u;
 277         struct bch_subvolume subvol;
 278         int ret = lockrestart_do(trans,
 279                 bch2_subvolume_get(trans, inum.subvol, true, 0, &subvol) ?:
 280                 bch2_inode_find_by_inum_trans(trans, inum, &inode_u)) ?:
 281                 PTR_ERR_OR_ZERO(inode = bch2_new_inode(trans));
 282         if (!ret) {
 283                 bch2_vfs_inode_init(trans, inum, inode, &inode_u, &subvol);
 284                 inode = bch2_inode_insert(c, inode);
 285         }
 286         bch2_trans_put(trans);
 287
 288         return ret ? ERR_PTR(ret) : &inode->v;
 289 }
 290
 291 struct bch_inode_info *
 292 __bch2_create(struct mnt_idmap *idmap,
 293               struct bch_inode_info *dir, struct dentry *dentry,
 294               umode_t mode, dev_t rdev, subvol_inum snapshot_src,
 295               unsigned flags)
 296 {
 297         struct bch_fs *c = dir->v.i_sb->s_fs_info;
 298         struct btree_trans *trans;
 299         struct bch_inode_unpacked dir_u;
 300         struct bch_inode_info *inode;
 301         struct bch_inode_unpacked inode_u;
 302         struct posix_acl *default_acl = NULL, *acl = NULL;
 303         subvol_inum inum;
 304         struct bch_subvolume subvol;
 305         u64 journal_seq = 0;
 306         int ret;
 307
 308         /*
 309          * preallocate acls + vfs inode before btree transaction, so that
 310          * nothing can fail after the transaction succeeds:
 311          */
 312 #ifdef CONFIG_BCACHEFS_POSIX_ACL
 313         ret = posix_acl_create(&dir->v, &mode, &default_acl, &acl);
 314         if (ret)
 315                 return ERR_PTR(ret);
 316 #endif
 317         inode = __bch2_new_inode(c);
 318         if (unlikely(!inode)) {
 319                 inode = ERR_PTR(-ENOMEM);
 320                 goto err;
 321         }
 322
 323         bch2_inode_init_early(c, &inode_u);
 324
 325         if (!(flags & BCH_CREATE_TMPFILE))
 326                 mutex_lock(&dir->ei_update_lock);
 327
 328         trans = bch2_trans_get(c);
 329 retry:
 330         bch2_trans_begin(trans);
 331
 332         ret   = bch2_subvol_is_ro_trans(trans, dir->ei_subvol) ?:
 333                 bch2_create_trans(trans,
 334                                   inode_inum(dir), &dir_u, &inode_u,
 335                                   !(flags & BCH_CREATE_TMPFILE)
 336                                   ? &dentry->d_name : NULL,
 337                                   from_kuid(i_user_ns(&dir->v), current_fsuid()),
 338                                   from_kgid(i_user_ns(&dir->v), current_fsgid()),
 339                                   mode, rdev,
 340                                   default_acl, acl, snapshot_src, flags) ?:
 341                 bch2_quota_acct(c, bch_qid(&inode_u), Q_INO, 1,
 342                                 KEY_TYPE_QUOTA_PREALLOC);
 343         if (unlikely(ret))
 344                 goto err_before_quota;
 345
 346         inum.subvol = inode_u.bi_subvol ?: dir->ei_subvol;
 347         inum.inum = inode_u.bi_inum;
 348
 349         ret   = bch2_subvolume_get(trans, inum.subvol, true,
 350                                    BTREE_ITER_with_updates, &subvol) ?:
 351                 bch2_trans_commit(trans, NULL, &journal_seq, 0);
 352         if (unlikely(ret)) {
 353                 bch2_quota_acct(c, bch_qid(&inode_u), Q_INO, -1,
 354                                 KEY_TYPE_QUOTA_WARN);
 355 err_before_quota:
 356                 if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
 357                         goto retry;
 358                 goto err_trans;
 359         }
 360
 361         if (!(flags & BCH_CREATE_TMPFILE)) {
 362                 bch2_inode_update_after_write(trans, dir, &dir_u,
 363                                               ATTR_MTIME|ATTR_CTIME);
 364                 mutex_unlock(&dir->ei_update_lock);
 365         }
 366
 367         bch2_vfs_inode_init(trans, inum, inode, &inode_u, &subvol);
 368
 369         set_cached_acl(&inode->v, ACL_TYPE_ACCESS, acl);
 370         set_cached_acl(&inode->v, ACL_TYPE_DEFAULT, default_acl);
 371
 372         /*
 373          * we must insert the new inode into the inode cache before calling
 374          * bch2_trans_exit() and dropping locks, else we could race with another
 375          * thread pulling the inode in and modifying it:
 376          */
 377         inode = bch2_inode_insert(c, inode);
 378         bch2_trans_put(trans);
 379 err:
 380         posix_acl_release(default_acl);
 381         posix_acl_release(acl);
 382         return inode;
 383 err_trans:
 384         if (!(flags & BCH_CREATE_TMPFILE))
 385                 mutex_unlock(&dir->ei_update_lock);
 386
 387         bch2_trans_put(trans);
 388         make_bad_inode(&inode->v);
 389         iput(&inode->v);
 390         inode = ERR_PTR(ret);
 391         goto err;
 392 }
 393
 394 /* methods */
 395
 396 static struct bch_inode_info *bch2_lookup_trans(struct btree_trans *trans,
 397                         subvol_inum dir, struct bch_hash_info *dir_hash_info,
 398                         const struct qstr *name)
 399 {
 400         struct bch_fs *c = trans->c;
 401         struct btree_iter dirent_iter = {};
 402         subvol_inum inum = {};
 403         struct printbuf buf = PRINTBUF;
 404
 405         struct bkey_s_c k = bch2_hash_lookup(trans, &dirent_iter, bch2_dirent_hash_desc,
 406                                              dir_hash_info, dir, name, 0);
 407         int ret = bkey_err(k);
 408         if (ret)
 409                 return ERR_PTR(ret);
 410
 411         ret = bch2_dirent_read_target(trans, dir, bkey_s_c_to_dirent(k), &inum);
 412         if (ret > 0)
 413                 ret = -ENOENT;
 414         if (ret)
 415                 goto err;
 416
 417         struct bch_inode_info *inode =
 418                 to_bch_ei(ilookup5_nowait(c->vfs_sb,
 419                                           bch2_inode_hash(inum),
 420                                           bch2_iget5_test,
 421                                           &inum));
 422         if (inode)
 423                 goto out;
 424
 425         struct bch_subvolume subvol;
 426         struct bch_inode_unpacked inode_u;
 427         ret =   bch2_subvolume_get(trans, inum.subvol, true, 0, &subvol) ?:
 428                 bch2_inode_find_by_inum_nowarn_trans(trans, inum, &inode_u) ?:
 429                 PTR_ERR_OR_ZERO(inode = bch2_new_inode(trans));
 430
 431         bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT),
 432                                 c, "dirent to missing inode:\n  %s",
 433                                 (bch2_bkey_val_to_text(&buf, c, k), buf.buf));
 434         if (ret)
 435                 goto err;
 436
 437         /* regular files may have hardlinks: */
 438         if (bch2_fs_inconsistent_on(bch2_inode_should_have_bp(&inode_u) &&
 439                                     !bkey_eq(k.k->p, POS(inode_u.bi_dir, inode_u.bi_dir_offset)),
 440                                     c,
 441                                     "dirent points to inode that does not point back:\n  %s",
 442                                     (bch2_bkey_val_to_text(&buf, c, k),
 443                                      prt_printf(&buf, "\n  "),
 444                                      bch2_inode_unpacked_to_text(&buf, &inode_u),
 445                                      buf.buf))) {
 446                 ret = -ENOENT;
 447                 goto err;
 448         }
 449
 450         bch2_vfs_inode_init(trans, inum, inode, &inode_u, &subvol);
 451         inode = bch2_inode_insert(c, inode);
 452 out:
 453         bch2_trans_iter_exit(trans, &dirent_iter);
 454         printbuf_exit(&buf);
 455         return inode;
 456 err:
 457         inode = ERR_PTR(ret);
 458         goto out;
 459 }
 460
 461 static struct dentry *bch2_lookup(struct inode *vdir, struct dentry *dentry,
 462                                   unsigned int flags)
 463 {
 464         struct bch_fs *c = vdir->i_sb->s_fs_info;
 465         struct bch_inode_info *dir = to_bch_ei(vdir);
 466         struct bch_hash_info hash = bch2_hash_info_init(c, &dir->ei_inode);
 467
 468         struct bch_inode_info *inode;
 469         bch2_trans_do(c, NULL, NULL, 0,
 470                 PTR_ERR_OR_ZERO(inode = bch2_lookup_trans(trans, inode_inum(dir),
 471                                                           &hash, &dentry->d_name)));
 472         if (IS_ERR(inode))
 473                 inode = NULL;
 474
 475         return d_splice_alias(&inode->v, dentry);
 476 }
 477
 478 static int bch2_mknod(struct mnt_idmap *idmap,
 479                       struct inode *vdir, struct dentry *dentry,
 480                       umode_t mode, dev_t rdev)
 481 {
 482         struct bch_inode_info *inode =
 483                 __bch2_create(idmap, to_bch_ei(vdir), dentry, mode, rdev,
 484                               (subvol_inum) { 0 }, 0);
 485
 486         if (IS_ERR(inode))
 487                 return bch2_err_class(PTR_ERR(inode));
 488
 489         d_instantiate(dentry, &inode->v);
 490         return 0;
 491 }
 492
 493 static int bch2_create(struct mnt_idmap *idmap,
 494                        struct inode *vdir, struct dentry *dentry,
 495                        umode_t mode, bool excl)
 496 {
 497         return bch2_mknod(idmap, vdir, dentry, mode|S_IFREG, 0);
 498 }
 499
 500 static int __bch2_link(struct bch_fs *c,
 501                        struct bch_inode_info *inode,
 502                        struct bch_inode_info *dir,
 503                        struct dentry *dentry)
 504 {
 505         struct btree_trans *trans = bch2_trans_get(c);
 506         struct bch_inode_unpacked dir_u, inode_u;
 507         int ret;
 508
 509         mutex_lock(&inode->ei_update_lock);
 510
 511         ret = commit_do(trans, NULL, NULL, 0,
 512                         bch2_link_trans(trans,
 513                                         inode_inum(dir),   &dir_u,
 514                                         inode_inum(inode), &inode_u,
 515                                         &dentry->d_name));
 516
 517         if (likely(!ret)) {
 518                 bch2_inode_update_after_write(trans, dir, &dir_u,
 519                                               ATTR_MTIME|ATTR_CTIME);
 520                 bch2_inode_update_after_write(trans, inode, &inode_u, ATTR_CTIME);
 521         }
 522
 523         bch2_trans_put(trans);
 524         mutex_unlock(&inode->ei_update_lock);
 525         return ret;
 526 }
 527
 528 static int bch2_link(struct dentry *old_dentry, struct inode *vdir,
 529                      struct dentry *dentry)
 530 {
 531         struct bch_fs *c = vdir->i_sb->s_fs_info;
 532         struct bch_inode_info *dir = to_bch_ei(vdir);
 533         struct bch_inode_info *inode = to_bch_ei(old_dentry->d_inode);
 534         int ret;
 535
 536         lockdep_assert_held(&inode->v.i_rwsem);
 537
 538         ret   = bch2_subvol_is_ro(c, dir->ei_subvol) ?:
 539                 bch2_subvol_is_ro(c, inode->ei_subvol) ?:
 540                 __bch2_link(c, inode, dir, dentry);
 541         if (unlikely(ret))
 542                 return bch2_err_class(ret);
 543
 544         ihold(&inode->v);
 545         d_instantiate(dentry, &inode->v);
 546         return 0;
 547 }
 548
 549 int __bch2_unlink(struct inode *vdir, struct dentry *dentry,
 550                   bool deleting_snapshot)
 551 {
 552         struct bch_fs *c = vdir->i_sb->s_fs_info;
 553         struct bch_inode_info *dir = to_bch_ei(vdir);
 554         struct bch_inode_info *inode = to_bch_ei(dentry->d_inode);
 555         struct bch_inode_unpacked dir_u, inode_u;
 556         struct btree_trans *trans = bch2_trans_get(c);
 557         int ret;
 558
 559         bch2_lock_inodes(INODE_UPDATE_LOCK, dir, inode);
 560
 561         ret = commit_do(trans, NULL, NULL,
 562                         BCH_TRANS_COMMIT_no_enospc,
 563                 bch2_unlink_trans(trans,
 564                                   inode_inum(dir), &dir_u,
 565                                   &inode_u, &dentry->d_name,
 566                                   deleting_snapshot));
 567         if (unlikely(ret))
 568                 goto err;
 569
 570         bch2_inode_update_after_write(trans, dir, &dir_u,
 571                                       ATTR_MTIME|ATTR_CTIME);
 572         bch2_inode_update_after_write(trans, inode, &inode_u,
 573                                       ATTR_MTIME);
 574
 575         if (inode_u.bi_subvol) {
 576                 /*
 577                  * Subvolume deletion is asynchronous, but we still want to tell
 578                  * the VFS that it's been deleted here:
 579                  */
 580                 set_nlink(&inode->v, 0);
 581         }
 582 err:
 583         bch2_unlock_inodes(INODE_UPDATE_LOCK, dir, inode);
 584         bch2_trans_put(trans);
 585
 586         return ret;
 587 }
 588
 589 static int bch2_unlink(struct inode *vdir, struct dentry *dentry)
 590 {
 591         struct bch_inode_info *dir= to_bch_ei(vdir);
 592         struct bch_fs *c = dir->v.i_sb->s_fs_info;
 593
 594         int ret = bch2_subvol_is_ro(c, dir->ei_subvol) ?:
 595                 __bch2_unlink(vdir, dentry, false);
 596         return bch2_err_class(ret);
 597 }
 598
 599 static int bch2_symlink(struct mnt_idmap *idmap,
 600                         struct inode *vdir, struct dentry *dentry,
 601                         const char *symname)
 602 {
 603         struct bch_fs *c = vdir->i_sb->s_fs_info;
 604         struct bch_inode_info *dir = to_bch_ei(vdir), *inode;
 605         int ret;
 606
 607         inode = __bch2_create(idmap, dir, dentry, S_IFLNK|S_IRWXUGO, 0,
 608                               (subvol_inum) { 0 }, BCH_CREATE_TMPFILE);
 609         if (IS_ERR(inode))
 610                 return bch2_err_class(PTR_ERR(inode));
 611
 612         inode_lock(&inode->v);
 613         ret = page_symlink(&inode->v, symname, strlen(symname) + 1);
 614         inode_unlock(&inode->v);
 615
 616         if (unlikely(ret))
 617                 goto err;
 618
 619         ret = filemap_write_and_wait_range(inode->v.i_mapping, 0, LLONG_MAX);
 620         if (unlikely(ret))
 621                 goto err;
 622
 623         ret = __bch2_link(c, inode, dir, dentry);
 624         if (unlikely(ret))
 625                 goto err;
 626
 627         d_instantiate(dentry, &inode->v);
 628         return 0;
 629 err:
 630         iput(&inode->v);
 631         return bch2_err_class(ret);
 632 }
 633
 634 static int bch2_mkdir(struct mnt_idmap *idmap,
 635                       struct inode *vdir, struct dentry *dentry, umode_t mode)
 636 {
 637         return bch2_mknod(idmap, vdir, dentry, mode|S_IFDIR, 0);
 638 }
 639
 640 static int bch2_rename2(struct mnt_idmap *idmap,
 641                         struct inode *src_vdir, struct dentry *src_dentry,
 642                         struct inode *dst_vdir, struct dentry *dst_dentry,
 643                         unsigned flags)
 644 {
 645         struct bch_fs *c = src_vdir->i_sb->s_fs_info;
 646         struct bch_inode_info *src_dir = to_bch_ei(src_vdir);
 647         struct bch_inode_info *dst_dir = to_bch_ei(dst_vdir);
 648         struct bch_inode_info *src_inode = to_bch_ei(src_dentry->d_inode);
 649         struct bch_inode_info *dst_inode = to_bch_ei(dst_dentry->d_inode);
 650         struct bch_inode_unpacked dst_dir_u, src_dir_u;
 651         struct bch_inode_unpacked src_inode_u, dst_inode_u;
 652         struct btree_trans *trans;
 653         enum bch_rename_mode mode = flags & RENAME_EXCHANGE
 654                 ? BCH_RENAME_EXCHANGE
 655                 : dst_dentry->d_inode
 656                 ? BCH_RENAME_OVERWRITE : BCH_RENAME;
 657         int ret;
 658
 659         if (flags & ~(RENAME_NOREPLACE|RENAME_EXCHANGE))
 660                 return -EINVAL;
 661
 662         if (mode == BCH_RENAME_OVERWRITE) {
 663                 ret = filemap_write_and_wait_range(src_inode->v.i_mapping,
 664                                                    0, LLONG_MAX);
 665                 if (ret)
 666                         return ret;
 667         }
 668
 669         trans = bch2_trans_get(c);
 670
 671         bch2_lock_inodes(INODE_UPDATE_LOCK,
 672                          src_dir,
 673                          dst_dir,
 674                          src_inode,
 675                          dst_inode);
 676
 677         ret   = bch2_subvol_is_ro_trans(trans, src_dir->ei_subvol) ?:
 678                 bch2_subvol_is_ro_trans(trans, dst_dir->ei_subvol);
 679         if (ret)
 680                 goto err;
 681
 682         if (inode_attr_changing(dst_dir, src_inode, Inode_opt_project)) {
 683                 ret = bch2_fs_quota_transfer(c, src_inode,
 684                                              dst_dir->ei_qid,
 685                                              1 << QTYP_PRJ,
 686                                              KEY_TYPE_QUOTA_PREALLOC);
 687                 if (ret)
 688                         goto err;
 689         }
 690
 691         if (mode == BCH_RENAME_EXCHANGE &&
 692             inode_attr_changing(src_dir, dst_inode, Inode_opt_project)) {
 693                 ret = bch2_fs_quota_transfer(c, dst_inode,
 694                                              src_dir->ei_qid,
 695                                              1 << QTYP_PRJ,
 696                                              KEY_TYPE_QUOTA_PREALLOC);
 697                 if (ret)
 698                         goto err;
 699         }
 700
 701         ret = commit_do(trans, NULL, NULL, 0,
 702                         bch2_rename_trans(trans,
 703                                           inode_inum(src_dir), &src_dir_u,
 704                                           inode_inum(dst_dir), &dst_dir_u,
 705                                           &src_inode_u,
 706                                           &dst_inode_u,
 707                                           &src_dentry->d_name,
 708                                           &dst_dentry->d_name,
 709                                           mode));
 710         if (unlikely(ret))
 711                 goto err;
 712
 713         BUG_ON(src_inode->v.i_ino != src_inode_u.bi_inum);
 714         BUG_ON(dst_inode &&
 715                dst_inode->v.i_ino != dst_inode_u.bi_inum);
 716
 717         bch2_inode_update_after_write(trans, src_dir, &src_dir_u,
 718                                       ATTR_MTIME|ATTR_CTIME);
 719
 720         if (src_dir != dst_dir)
 721                 bch2_inode_update_after_write(trans, dst_dir, &dst_dir_u,
 722                                               ATTR_MTIME|ATTR_CTIME);
 723
 724         bch2_inode_update_after_write(trans, src_inode, &src_inode_u,
 725                                       ATTR_CTIME);
 726
 727         if (dst_inode)
 728                 bch2_inode_update_after_write(trans, dst_inode, &dst_inode_u,
 729                                               ATTR_CTIME);
 730 err:
 731         bch2_trans_put(trans);
 732
 733         bch2_fs_quota_transfer(c, src_inode,
 734                                bch_qid(&src_inode->ei_inode),
 735                                1 << QTYP_PRJ,
 736                                KEY_TYPE_QUOTA_NOCHECK);
 737         if (dst_inode)
 738                 bch2_fs_quota_transfer(c, dst_inode,
 739                                        bch_qid(&dst_inode->ei_inode),
 740                                        1 << QTYP_PRJ,
 741                                        KEY_TYPE_QUOTA_NOCHECK);
 742
 743         bch2_unlock_inodes(INODE_UPDATE_LOCK,
 744                            src_dir,
 745                            dst_dir,
 746                            src_inode,
 747                            dst_inode);
 748
 749         return bch2_err_class(ret);
 750 }
 751
 752 static void bch2_setattr_copy(struct mnt_idmap *idmap,
 753                               struct bch_inode_info *inode,
 754                               struct bch_inode_unpacked *bi,
 755                               struct iattr *attr)
 756 {
 757         struct bch_fs *c = inode->v.i_sb->s_fs_info;
 758         unsigned int ia_valid = attr->ia_valid;
 759
 760         if (ia_valid & ATTR_UID)
 761                 bi->bi_uid = from_kuid(i_user_ns(&inode->v), attr->ia_uid);
 762         if (ia_valid & ATTR_GID)
 763                 bi->bi_gid = from_kgid(i_user_ns(&inode->v), attr->ia_gid);
 764
 765         if (ia_valid & ATTR_SIZE)
 766                 bi->bi_size = attr->ia_size;
 767
 768         if (ia_valid & ATTR_ATIME)
 769                 bi->bi_atime = timespec_to_bch2_time(c, attr->ia_atime);
 770         if (ia_valid & ATTR_MTIME)
 771                 bi->bi_mtime = timespec_to_bch2_time(c, attr->ia_mtime);
 772         if (ia_valid & ATTR_CTIME)
 773                 bi->bi_ctime = timespec_to_bch2_time(c, attr->ia_ctime);
 774
 775         if (ia_valid & ATTR_MODE) {
 776                 umode_t mode = attr->ia_mode;
 777                 kgid_t gid = ia_valid & ATTR_GID
 778                         ? attr->ia_gid
 779                         : inode->v.i_gid;
 780
 781                 if (!in_group_p(gid) &&
 782                     !capable_wrt_inode_uidgid(idmap, &inode->v, CAP_FSETID))
 783                         mode &= ~S_ISGID;
 784                 bi->bi_mode = mode;
 785         }
 786 }
 787
 788 int bch2_setattr_nonsize(struct mnt_idmap *idmap,
 789                          struct bch_inode_info *inode,
 790                          struct iattr *attr)
 791 {
 792         struct bch_fs *c = inode->v.i_sb->s_fs_info;
 793         struct bch_qid qid;
 794         struct btree_trans *trans;
 795         struct btree_iter inode_iter = { NULL };
 796         struct bch_inode_unpacked inode_u;
 797         struct posix_acl *acl = NULL;
 798         int ret;
 799
 800         mutex_lock(&inode->ei_update_lock);
 801
 802         qid = inode->ei_qid;
 803
 804         if (attr->ia_valid & ATTR_UID)
 805                 qid.q[QTYP_USR] = from_kuid(i_user_ns(&inode->v), attr->ia_uid);
 806
 807         if (attr->ia_valid & ATTR_GID)
 808                 qid.q[QTYP_GRP] = from_kgid(i_user_ns(&inode->v), attr->ia_gid);
 809
 810         ret = bch2_fs_quota_transfer(c, inode, qid, ~0,
 811                                      KEY_TYPE_QUOTA_PREALLOC);
 812         if (ret)
 813                 goto err;
 814
 815         trans = bch2_trans_get(c);
 816 retry:
 817         bch2_trans_begin(trans);
 818         kfree(acl);
 819         acl = NULL;
 820
 821         ret = bch2_inode_peek(trans, &inode_iter, &inode_u, inode_inum(inode),
 822                               BTREE_ITER_intent);
 823         if (ret)
 824                 goto btree_err;
 825
 826         bch2_setattr_copy(idmap, inode, &inode_u, attr);
 827
 828         if (attr->ia_valid & ATTR_MODE) {
 829                 ret = bch2_acl_chmod(trans, inode_inum(inode), &inode_u,
 830                                      inode_u.bi_mode, &acl);
 831                 if (ret)
 832                         goto btree_err;
 833         }
 834
 835         ret =   bch2_inode_write(trans, &inode_iter, &inode_u) ?:
 836                 bch2_trans_commit(trans, NULL, NULL,
 837                                   BCH_TRANS_COMMIT_no_enospc);
 838 btree_err:
 839         bch2_trans_iter_exit(trans, &inode_iter);
 840
 841         if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
 842                 goto retry;
 843         if (unlikely(ret))
 844                 goto err_trans;
 845
 846         bch2_inode_update_after_write(trans, inode, &inode_u, attr->ia_valid);
 847
 848         if (acl)
 849                 set_cached_acl(&inode->v, ACL_TYPE_ACCESS, acl);
 850 err_trans:
 851         bch2_trans_put(trans);
 852 err:
 853         mutex_unlock(&inode->ei_update_lock);
 854
 855         return bch2_err_class(ret);
 856 }
 857
 858 static int bch2_getattr(struct mnt_idmap *idmap,
 859                         const struct path *path, struct kstat *stat,
 860                         u32 request_mask, unsigned query_flags)
 861 {
 862         struct bch_inode_info *inode = to_bch_ei(d_inode(path->dentry));
 863         struct bch_fs *c = inode->v.i_sb->s_fs_info;
 864
 865         stat->dev       = inode->v.i_sb->s_dev;
 866         stat->ino       = inode->v.i_ino;
 867         stat->mode      = inode->v.i_mode;
 868         stat->nlink     = inode->v.i_nlink;
 869         stat->uid       = inode->v.i_uid;
 870         stat->gid       = inode->v.i_gid;
 871         stat->rdev      = inode->v.i_rdev;
 872         stat->size      = i_size_read(&inode->v);
 873         stat->atime     = inode_get_atime(&inode->v);
 874         stat->mtime     = inode_get_mtime(&inode->v);
 875         stat->ctime     = inode_get_ctime(&inode->v);
 876         stat->blksize   = block_bytes(c);
 877         stat->blocks    = inode->v.i_blocks;
 878
 879         stat->subvol    = inode->ei_subvol;
 880         stat->result_mask |= STATX_SUBVOL;
 881
 882         if (request_mask & STATX_BTIME) {
 883                 stat->result_mask |= STATX_BTIME;
 884                 stat->btime = bch2_time_to_timespec(c, inode->ei_inode.bi_otime);
 885         }
 886
 887         if (inode->ei_inode.bi_flags & BCH_INODE_immutable)
 888                 stat->attributes |= STATX_ATTR_IMMUTABLE;
 889         stat->attributes_mask    |= STATX_ATTR_IMMUTABLE;
 890
 891         if (inode->ei_inode.bi_flags & BCH_INODE_append)
 892                 stat->attributes |= STATX_ATTR_APPEND;
 893         stat->attributes_mask    |= STATX_ATTR_APPEND;
 894
 895         if (inode->ei_inode.bi_flags & BCH_INODE_nodump)
 896                 stat->attributes |= STATX_ATTR_NODUMP;
 897         stat->attributes_mask    |= STATX_ATTR_NODUMP;
 898
 899         return 0;
 900 }
 901
 902 static int bch2_setattr(struct mnt_idmap *idmap,
 903                         struct dentry *dentry, struct iattr *iattr)
 904 {
 905         struct bch_inode_info *inode = to_bch_ei(dentry->d_inode);
 906         struct bch_fs *c = inode->v.i_sb->s_fs_info;
 907         int ret;
 908
 909         lockdep_assert_held(&inode->v.i_rwsem);
 910
 911         ret   = bch2_subvol_is_ro(c, inode->ei_subvol) ?:
 912                 setattr_prepare(idmap, dentry, iattr);
 913         if (ret)
 914                 return ret;
 915
 916         return iattr->ia_valid & ATTR_SIZE
 917                 ? bchfs_truncate(idmap, inode, iattr)
 918                 : bch2_setattr_nonsize(idmap, inode, iattr);
 919 }
 920
 921 static int bch2_tmpfile(struct mnt_idmap *idmap,
 922                         struct inode *vdir, struct file *file, umode_t mode)
 923 {
 924         struct bch_inode_info *inode =
 925                 __bch2_create(idmap, to_bch_ei(vdir),
 926                               file->f_path.dentry, mode, 0,
 927                               (subvol_inum) { 0 }, BCH_CREATE_TMPFILE);
 928
 929         if (IS_ERR(inode))
 930                 return bch2_err_class(PTR_ERR(inode));
 931
 932         d_mark_tmpfile(file, &inode->v);
 933         d_instantiate(file->f_path.dentry, &inode->v);
 934         return finish_open_simple(file, 0);
 935 }
 936
 937 static int bch2_fill_extent(struct bch_fs *c,
 938                             struct fiemap_extent_info *info,
 939                             struct bkey_s_c k, unsigned flags)
 940 {
 941         if (bkey_extent_is_direct_data(k.k)) {
 942                 struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
 943                 const union bch_extent_entry *entry;
 944                 struct extent_ptr_decoded p;
 945                 int ret;
 946
 947                 if (k.k->type == KEY_TYPE_reflink_v)
 948                         flags |= FIEMAP_EXTENT_SHARED;
 949
 950                 bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
 951                         int flags2 = 0;
 952                         u64 offset = p.ptr.offset;
 953
 954                         if (p.ptr.unwritten)
 955                                 flags2 |= FIEMAP_EXTENT_UNWRITTEN;
 956
 957                         if (p.crc.compression_type)
 958                                 flags2 |= FIEMAP_EXTENT_ENCODED;
 959                         else
 960                                 offset += p.crc.offset;
 961
 962                         if ((offset & (block_sectors(c) - 1)) ||
 963                             (k.k->size & (block_sectors(c) - 1)))
 964                                 flags2 |= FIEMAP_EXTENT_NOT_ALIGNED;
 965
 966                         ret = fiemap_fill_next_extent(info,
 967                                                 bkey_start_offset(k.k) << 9,
 968                                                 offset << 9,
 969                                                 k.k->size << 9, flags|flags2);
 970                         if (ret)
 971                                 return ret;
 972                 }
 973
 974                 return 0;
 975         } else if (bkey_extent_is_inline_data(k.k)) {
 976                 return fiemap_fill_next_extent(info,
 977                                                bkey_start_offset(k.k) << 9,
 978                                                0, k.k->size << 9,
 979                                                flags|
 980                                                FIEMAP_EXTENT_DATA_INLINE);
 981         } else if (k.k->type == KEY_TYPE_reservation) {
 982                 return fiemap_fill_next_extent(info,
 983                                                bkey_start_offset(k.k) << 9,
 984                                                0, k.k->size << 9,
 985                                                flags|
 986                                                FIEMAP_EXTENT_DELALLOC|
 987                                                FIEMAP_EXTENT_UNWRITTEN);
 988         } else {
 989                 BUG();
 990         }
 991 }
 992
 993 static int bch2_fiemap(struct inode *vinode, struct fiemap_extent_info *info,
 994                        u64 start, u64 len)
 995 {
 996         struct bch_fs *c = vinode->i_sb->s_fs_info;
 997         struct bch_inode_info *ei = to_bch_ei(vinode);
 998         struct btree_trans *trans;
 999         struct btree_iter iter;
1000         struct bkey_s_c k;
1001         struct bkey_buf cur, prev;
1002         unsigned offset_into_extent, sectors;
1003         bool have_extent = false;
1004         u32 snapshot;
1005         int ret = 0;
1006
1007         ret = fiemap_prep(&ei->v, info, start, &len, FIEMAP_FLAG_SYNC);
1008         if (ret)
1009                 return ret;
1010
1011         struct bpos end = POS(ei->v.i_ino, (start + len) >> 9);
1012         if (start + len < start)
1013                 return -EINVAL;
1014
1015         start >>= 9;
1016
1017         bch2_bkey_buf_init(&cur);
1018         bch2_bkey_buf_init(&prev);
1019         trans = bch2_trans_get(c);
1020 retry:
1021         bch2_trans_begin(trans);
1022
1023         ret = bch2_subvolume_get_snapshot(trans, ei->ei_subvol, &snapshot);
1024         if (ret)
1025                 goto err;
1026
1027         bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
1028                              SPOS(ei->v.i_ino, start, snapshot), 0);
1029
1030         while (!(ret = btree_trans_too_many_iters(trans)) &&
1031                (k = bch2_btree_iter_peek_upto(&iter, end)).k &&
1032                !(ret = bkey_err(k))) {
1033                 enum btree_id data_btree = BTREE_ID_extents;
1034
1035                 if (!bkey_extent_is_data(k.k) &&
1036                     k.k->type != KEY_TYPE_reservation) {
1037                         bch2_btree_iter_advance(&iter);
1038                         continue;
1039                 }
1040
1041                 offset_into_extent      = iter.pos.offset -
1042                         bkey_start_offset(k.k);
1043                 sectors                 = k.k->size - offset_into_extent;
1044
1045                 bch2_bkey_buf_reassemble(&cur, c, k);
1046
1047                 ret = bch2_read_indirect_extent(trans, &data_btree,
1048                                         &offset_into_extent, &cur);
1049                 if (ret)
1050                         break;
1051
1052                 k = bkey_i_to_s_c(cur.k);
1053                 bch2_bkey_buf_realloc(&prev, c, k.k->u64s);
1054
1055                 sectors = min(sectors, k.k->size - offset_into_extent);
1056
1057                 bch2_cut_front(POS(k.k->p.inode,
1058                                    bkey_start_offset(k.k) +
1059                                    offset_into_extent),
1060                                cur.k);
1061                 bch2_key_resize(&cur.k->k, sectors);
1062                 cur.k->k.p = iter.pos;
1063                 cur.k->k.p.offset += cur.k->k.size;
1064
1065                 if (have_extent) {
1066                         bch2_trans_unlock(trans);
1067                         ret = bch2_fill_extent(c, info,
1068                                         bkey_i_to_s_c(prev.k), 0);
1069                         if (ret)
1070                                 break;
1071                 }
1072
1073                 bkey_copy(prev.k, cur.k);
1074                 have_extent = true;
1075
1076                 bch2_btree_iter_set_pos(&iter,
1077                         POS(iter.pos.inode, iter.pos.offset + sectors));
1078
1079                 ret = bch2_trans_relock(trans);
1080                 if (ret)
1081                         break;
1082         }
1083         start = iter.pos.offset;
1084         bch2_trans_iter_exit(trans, &iter);
1085 err:
1086         if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
1087                 goto retry;
1088
1089         if (!ret && have_extent) {
1090                 bch2_trans_unlock(trans);
1091                 ret = bch2_fill_extent(c, info, bkey_i_to_s_c(prev.k),
1092                                        FIEMAP_EXTENT_LAST);
1093         }
1094
1095         bch2_trans_put(trans);
1096         bch2_bkey_buf_exit(&cur, c);
1097         bch2_bkey_buf_exit(&prev, c);
1098         return ret < 0 ? ret : 0;
1099 }
1100
1101 static const struct vm_operations_struct bch_vm_ops = {
1102         .fault          = bch2_page_fault,
1103         .map_pages      = filemap_map_pages,
1104         .page_mkwrite   = bch2_page_mkwrite,
1105 };
1106
1107 static int bch2_mmap(struct file *file, struct vm_area_struct *vma)
1108 {
1109         file_accessed(file);
1110
1111         vma->vm_ops = &bch_vm_ops;
1112         return 0;
1113 }
1114
1115 /* Directories: */
1116
1117 static loff_t bch2_dir_llseek(struct file *file, loff_t offset, int whence)
1118 {
1119         return generic_file_llseek_size(file, offset, whence,
1120                                         S64_MAX, S64_MAX);
1121 }
1122
1123 static int bch2_vfs_readdir(struct file *file, struct dir_context *ctx)
1124 {
1125         struct bch_inode_info *inode = file_bch_inode(file);
1126         struct bch_fs *c = inode->v.i_sb->s_fs_info;
1127
1128         if (!dir_emit_dots(file, ctx))
1129                 return 0;
1130
1131         int ret = bch2_readdir(c, inode_inum(inode), ctx);
1132
1133         bch_err_fn(c, ret);
1134         return bch2_err_class(ret);
1135 }
1136
1137 static int bch2_open(struct inode *vinode, struct file *file)
1138 {
1139         if (file->f_flags & (O_WRONLY|O_RDWR)) {
1140                 struct bch_inode_info *inode = to_bch_ei(vinode);
1141                 struct bch_fs *c = inode->v.i_sb->s_fs_info;
1142
1143                 int ret = bch2_subvol_is_ro(c, inode->ei_subvol);
1144                 if (ret)
1145                         return ret;
1146         }
1147
1148         return generic_file_open(vinode, file);
1149 }
1150
1151 static const struct file_operations bch_file_operations = {
1152         .open           = bch2_open,
1153         .llseek         = bch2_llseek,
1154         .read_iter      = bch2_read_iter,
1155         .write_iter     = bch2_write_iter,
1156         .mmap           = bch2_mmap,
1157         .fsync          = bch2_fsync,
1158         .splice_read    = filemap_splice_read,
1159         .splice_write   = iter_file_splice_write,
1160         .fallocate      = bch2_fallocate_dispatch,
1161         .unlocked_ioctl = bch2_fs_file_ioctl,
1162 #ifdef CONFIG_COMPAT
1163         .compat_ioctl   = bch2_compat_fs_ioctl,
1164 #endif
1165         .remap_file_range = bch2_remap_file_range,
1166 };
1167
1168 static const struct inode_operations bch_file_inode_operations = {
1169         .getattr        = bch2_getattr,
1170         .setattr        = bch2_setattr,
1171         .fiemap         = bch2_fiemap,
1172         .listxattr      = bch2_xattr_list,
1173 #ifdef CONFIG_BCACHEFS_POSIX_ACL
1174         .get_acl        = bch2_get_acl,
1175         .set_acl        = bch2_set_acl,
1176 #endif
1177 };
1178
1179 static const struct inode_operations bch_dir_inode_operations = {
1180         .lookup         = bch2_lookup,
1181         .create         = bch2_create,
1182         .link           = bch2_link,
1183         .unlink         = bch2_unlink,
1184         .symlink        = bch2_symlink,
1185         .mkdir          = bch2_mkdir,
1186         .rmdir          = bch2_unlink,
1187         .mknod          = bch2_mknod,
1188         .rename         = bch2_rename2,
1189         .getattr        = bch2_getattr,
1190         .setattr        = bch2_setattr,
1191         .tmpfile        = bch2_tmpfile,
1192         .listxattr      = bch2_xattr_list,
1193 #ifdef CONFIG_BCACHEFS_POSIX_ACL
1194         .get_acl        = bch2_get_acl,
1195         .set_acl        = bch2_set_acl,
1196 #endif
1197 };
1198
1199 static const struct file_operations bch_dir_file_operations = {
1200         .llseek         = bch2_dir_llseek,
1201         .read           = generic_read_dir,
1202         .iterate_shared = bch2_vfs_readdir,
1203         .fsync          = bch2_fsync,
1204         .unlocked_ioctl = bch2_fs_file_ioctl,
1205 #ifdef CONFIG_COMPAT
1206         .compat_ioctl   = bch2_compat_fs_ioctl,
1207 #endif
1208 };
1209
1210 static const struct inode_operations bch_symlink_inode_operations = {
1211         .get_link       = page_get_link,
1212         .getattr        = bch2_getattr,
1213         .setattr        = bch2_setattr,
1214         .listxattr      = bch2_xattr_list,
1215 #ifdef CONFIG_BCACHEFS_POSIX_ACL
1216         .get_acl        = bch2_get_acl,
1217         .set_acl        = bch2_set_acl,
1218 #endif
1219 };
1220
1221 static const struct inode_operations bch_special_inode_operations = {
1222         .getattr        = bch2_getattr,
1223         .setattr        = bch2_setattr,
1224         .listxattr      = bch2_xattr_list,
1225 #ifdef CONFIG_BCACHEFS_POSIX_ACL
1226         .get_acl        = bch2_get_acl,
1227         .set_acl        = bch2_set_acl,
1228 #endif
1229 };
1230
1231 static const struct address_space_operations bch_address_space_operations = {
1232         .read_folio     = bch2_read_folio,
1233         .writepages     = bch2_writepages,
1234         .readahead      = bch2_readahead,
1235         .dirty_folio    = filemap_dirty_folio,
1236         .write_begin    = bch2_write_begin,
1237         .write_end      = bch2_write_end,
1238         .invalidate_folio = bch2_invalidate_folio,
1239         .release_folio  = bch2_release_folio,
1240         .direct_IO      = noop_direct_IO,
1241 #ifdef CONFIG_MIGRATION
1242         .migrate_folio  = filemap_migrate_folio,
1243 #endif
1244         .error_remove_folio = generic_error_remove_folio,
1245 };
1246
1247 struct bcachefs_fid {
1248         u64             inum;
1249         u32             subvol;
1250         u32             gen;
1251 } __packed;
1252
1253 struct bcachefs_fid_with_parent {
1254         struct bcachefs_fid     fid;
1255         struct bcachefs_fid     dir;
1256 } __packed;
1257
1258 static int bcachefs_fid_valid(int fh_len, int fh_type)
1259 {
1260         switch (fh_type) {
1261         case FILEID_BCACHEFS_WITHOUT_PARENT:
1262                 return fh_len == sizeof(struct bcachefs_fid) / sizeof(u32);
1263         case FILEID_BCACHEFS_WITH_PARENT:
1264                 return fh_len == sizeof(struct bcachefs_fid_with_parent) / sizeof(u32);
1265         default:
1266                 return false;
1267         }
1268 }
1269
1270 static struct bcachefs_fid bch2_inode_to_fid(struct bch_inode_info *inode)
1271 {
1272         return (struct bcachefs_fid) {
1273                 .inum   = inode->ei_inode.bi_inum,
1274                 .subvol = inode->ei_subvol,
1275                 .gen    = inode->ei_inode.bi_generation,
1276         };
1277 }
1278
1279 static int bch2_encode_fh(struct inode *vinode, u32 *fh, int *len,
1280                           struct inode *vdir)
1281 {
1282         struct bch_inode_info *inode    = to_bch_ei(vinode);
1283         struct bch_inode_info *dir      = to_bch_ei(vdir);
1284         int min_len;
1285
1286         if (!S_ISDIR(inode->v.i_mode) && dir) {
1287                 struct bcachefs_fid_with_parent *fid = (void *) fh;
1288
1289                 min_len = sizeof(*fid) / sizeof(u32);
1290                 if (*len < min_len) {
1291                         *len = min_len;
1292                         return FILEID_INVALID;
1293                 }
1294
1295                 fid->fid = bch2_inode_to_fid(inode);
1296                 fid->dir = bch2_inode_to_fid(dir);
1297
1298                 *len = min_len;
1299                 return FILEID_BCACHEFS_WITH_PARENT;
1300         } else {
1301                 struct bcachefs_fid *fid = (void *) fh;
1302
1303                 min_len = sizeof(*fid) / sizeof(u32);
1304                 if (*len < min_len) {
1305                         *len = min_len;
1306                         return FILEID_INVALID;
1307                 }
1308                 *fid = bch2_inode_to_fid(inode);
1309
1310                 *len = min_len;
1311                 return FILEID_BCACHEFS_WITHOUT_PARENT;
1312         }
1313 }
1314
1315 static struct inode *bch2_nfs_get_inode(struct super_block *sb,
1316                                         struct bcachefs_fid fid)
1317 {
1318         struct bch_fs *c = sb->s_fs_info;
1319         struct inode *vinode = bch2_vfs_inode_get(c, (subvol_inum) {
1320                                     .subvol = fid.subvol,
1321                                     .inum = fid.inum,
1322         });
1323         if (!IS_ERR(vinode) && vinode->i_generation != fid.gen) {
1324                 iput(vinode);
1325                 vinode = ERR_PTR(-ESTALE);
1326         }
1327         return vinode;
1328 }
1329
1330 static struct dentry *bch2_fh_to_dentry(struct super_block *sb, struct fid *_fid,
1331                 int fh_len, int fh_type)
1332 {
1333         struct bcachefs_fid *fid = (void *) _fid;
1334
1335         if (!bcachefs_fid_valid(fh_len, fh_type))
1336                 return NULL;
1337
1338         return d_obtain_alias(bch2_nfs_get_inode(sb, *fid));
1339 }
1340
1341 static struct dentry *bch2_fh_to_parent(struct super_block *sb, struct fid *_fid,
1342                 int fh_len, int fh_type)
1343 {
1344         struct bcachefs_fid_with_parent *fid = (void *) _fid;
1345
1346         if (!bcachefs_fid_valid(fh_len, fh_type) ||
1347             fh_type != FILEID_BCACHEFS_WITH_PARENT)
1348                 return NULL;
1349
1350         return d_obtain_alias(bch2_nfs_get_inode(sb, fid->dir));
1351 }
1352
1353 static struct dentry *bch2_get_parent(struct dentry *child)
1354 {
1355         struct bch_inode_info *inode = to_bch_ei(child->d_inode);
1356         struct bch_fs *c = inode->v.i_sb->s_fs_info;
1357         subvol_inum parent_inum = {
1358                 .subvol = inode->ei_inode.bi_parent_subvol ?:
1359                         inode->ei_subvol,
1360                 .inum = inode->ei_inode.bi_dir,
1361         };
1362
1363         return d_obtain_alias(bch2_vfs_inode_get(c, parent_inum));
1364 }
1365
1366 static int bch2_get_name(struct dentry *parent, char *name, struct dentry *child)
1367 {
1368         struct bch_inode_info *inode    = to_bch_ei(child->d_inode);
1369         struct bch_inode_info *dir      = to_bch_ei(parent->d_inode);
1370         struct bch_fs *c = inode->v.i_sb->s_fs_info;
1371         struct btree_trans *trans;
1372         struct btree_iter iter1;
1373         struct btree_iter iter2;
1374         struct bkey_s_c k;
1375         struct bkey_s_c_dirent d;
1376         struct bch_inode_unpacked inode_u;
1377         subvol_inum target;
1378         u32 snapshot;
1379         struct qstr dirent_name;
1380         unsigned name_len = 0;
1381         int ret;
1382
1383         if (!S_ISDIR(dir->v.i_mode))
1384                 return -EINVAL;
1385
1386         trans = bch2_trans_get(c);
1387
1388         bch2_trans_iter_init(trans, &iter1, BTREE_ID_dirents,
1389                              POS(dir->ei_inode.bi_inum, 0), 0);
1390         bch2_trans_iter_init(trans, &iter2, BTREE_ID_dirents,
1391                              POS(dir->ei_inode.bi_inum, 0), 0);
1392 retry:
1393         bch2_trans_begin(trans);
1394
1395         ret = bch2_subvolume_get_snapshot(trans, dir->ei_subvol, &snapshot);
1396         if (ret)
1397                 goto err;
1398
1399         bch2_btree_iter_set_snapshot(&iter1, snapshot);
1400         bch2_btree_iter_set_snapshot(&iter2, snapshot);
1401
1402         ret = bch2_inode_find_by_inum_trans(trans, inode_inum(inode), &inode_u);
1403         if (ret)
1404                 goto err;
1405
1406         if (inode_u.bi_dir == dir->ei_inode.bi_inum) {
1407                 bch2_btree_iter_set_pos(&iter1, POS(inode_u.bi_dir, inode_u.bi_dir_offset));
1408
1409                 k = bch2_btree_iter_peek_slot(&iter1);
1410                 ret = bkey_err(k);
1411                 if (ret)
1412                         goto err;
1413
1414                 if (k.k->type != KEY_TYPE_dirent) {
1415                         ret = -BCH_ERR_ENOENT_dirent_doesnt_match_inode;
1416                         goto err;
1417                 }
1418
1419                 d = bkey_s_c_to_dirent(k);
1420                 ret = bch2_dirent_read_target(trans, inode_inum(dir), d, &target);
1421                 if (ret > 0)
1422                         ret = -BCH_ERR_ENOENT_dirent_doesnt_match_inode;
1423                 if (ret)
1424                         goto err;
1425
1426                 if (target.subvol       == inode->ei_subvol &&
1427                     target.inum         == inode->ei_inode.bi_inum)
1428                         goto found;
1429         } else {
1430                 /*
1431                  * File with multiple hardlinks and our backref is to the wrong
1432                  * directory - linear search:
1433                  */
1434                 for_each_btree_key_continue_norestart(iter2, 0, k, ret) {
1435                         if (k.k->p.inode > dir->ei_inode.bi_inum)
1436                                 break;
1437
1438                         if (k.k->type != KEY_TYPE_dirent)
1439                                 continue;
1440
1441                         d = bkey_s_c_to_dirent(k);
1442                         ret = bch2_dirent_read_target(trans, inode_inum(dir), d, &target);
1443                         if (ret < 0)
1444                                 break;
1445                         if (ret)
1446                                 continue;
1447
1448                         if (target.subvol       == inode->ei_subvol &&
1449                             target.inum         == inode->ei_inode.bi_inum)
1450                                 goto found;
1451                 }
1452         }
1453
1454         ret = -ENOENT;
1455         goto err;
1456 found:
1457         dirent_name = bch2_dirent_get_name(d);
1458
1459         name_len = min_t(unsigned, dirent_name.len, NAME_MAX);
1460         memcpy(name, dirent_name.name, name_len);
1461         name[name_len] = '\0';
1462 err:
1463         if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
1464                 goto retry;
1465
1466         bch2_trans_iter_exit(trans, &iter1);
1467         bch2_trans_iter_exit(trans, &iter2);
1468         bch2_trans_put(trans);
1469
1470         return ret;
1471 }
1472
1473 static const struct export_operations bch_export_ops = {
1474         .encode_fh      = bch2_encode_fh,
1475         .fh_to_dentry   = bch2_fh_to_dentry,
1476         .fh_to_parent   = bch2_fh_to_parent,
1477         .get_parent     = bch2_get_parent,
1478         .get_name       = bch2_get_name,
1479 };
1480
1481 static void bch2_vfs_inode_init(struct btree_trans *trans, subvol_inum inum,
1482                                 struct bch_inode_info *inode,
1483                                 struct bch_inode_unpacked *bi,
1484                                 struct bch_subvolume *subvol)
1485 {
1486         bch2_iget5_set(&inode->v, &inum);
1487         bch2_inode_update_after_write(trans, inode, bi, ~0);
1488
1489         if (BCH_SUBVOLUME_SNAP(subvol))
1490                 set_bit(EI_INODE_SNAPSHOT, &inode->ei_flags);
1491         else
1492                 clear_bit(EI_INODE_SNAPSHOT, &inode->ei_flags);
1493
1494         inode->v.i_blocks       = bi->bi_sectors;
1495         inode->v.i_ino          = bi->bi_inum;
1496         inode->v.i_rdev         = bi->bi_dev;
1497         inode->v.i_generation   = bi->bi_generation;
1498         inode->v.i_size         = bi->bi_size;
1499
1500         inode->ei_flags         = 0;
1501         inode->ei_quota_reserved = 0;
1502         inode->ei_qid           = bch_qid(bi);
1503         inode->ei_subvol        = inum.subvol;
1504
1505         inode->v.i_mapping->a_ops = &bch_address_space_operations;
1506
1507         switch (inode->v.i_mode & S_IFMT) {
1508         case S_IFREG:
1509                 inode->v.i_op   = &bch_file_inode_operations;
1510                 inode->v.i_fop  = &bch_file_operations;
1511                 break;
1512         case S_IFDIR:
1513                 inode->v.i_op   = &bch_dir_inode_operations;
1514                 inode->v.i_fop  = &bch_dir_file_operations;
1515                 break;
1516         case S_IFLNK:
1517                 inode_nohighmem(&inode->v);
1518                 inode->v.i_op   = &bch_symlink_inode_operations;
1519                 break;
1520         default:
1521                 init_special_inode(&inode->v, inode->v.i_mode, inode->v.i_rdev);
1522                 inode->v.i_op   = &bch_special_inode_operations;
1523                 break;
1524         }
1525
1526         mapping_set_large_folios(inode->v.i_mapping);
1527 }
1528
1529 static void bch2_free_inode(struct inode *vinode)
1530 {
1531         kmem_cache_free(bch2_inode_cache, to_bch_ei(vinode));
1532 }
1533
1534 static int inode_update_times_fn(struct btree_trans *trans,
1535                                  struct bch_inode_info *inode,
1536                                  struct bch_inode_unpacked *bi,
1537                                  void *p)
1538 {
1539         struct bch_fs *c = inode->v.i_sb->s_fs_info;
1540
1541         bi->bi_atime    = timespec_to_bch2_time(c, inode_get_atime(&inode->v));
1542         bi->bi_mtime    = timespec_to_bch2_time(c, inode_get_mtime(&inode->v));
1543         bi->bi_ctime    = timespec_to_bch2_time(c, inode_get_ctime(&inode->v));
1544
1545         return 0;
1546 }
1547
1548 static int bch2_vfs_write_inode(struct inode *vinode,
1549                                 struct writeback_control *wbc)
1550 {
1551         struct bch_fs *c = vinode->i_sb->s_fs_info;
1552         struct bch_inode_info *inode = to_bch_ei(vinode);
1553         int ret;
1554
1555         mutex_lock(&inode->ei_update_lock);
1556         ret = bch2_write_inode(c, inode, inode_update_times_fn, NULL,
1557                                ATTR_ATIME|ATTR_MTIME|ATTR_CTIME);
1558         mutex_unlock(&inode->ei_update_lock);
1559
1560         return bch2_err_class(ret);
1561 }
1562
1563 static void bch2_evict_inode(struct inode *vinode)
1564 {
1565         struct bch_fs *c = vinode->i_sb->s_fs_info;
1566         struct bch_inode_info *inode = to_bch_ei(vinode);
1567
1568         truncate_inode_pages_final(&inode->v.i_data);
1569
1570         clear_inode(&inode->v);
1571
1572         BUG_ON(!is_bad_inode(&inode->v) && inode->ei_quota_reserved);
1573
1574         if (!inode->v.i_nlink && !is_bad_inode(&inode->v)) {
1575                 bch2_quota_acct(c, inode->ei_qid, Q_SPC, -((s64) inode->v.i_blocks),
1576                                 KEY_TYPE_QUOTA_WARN);
1577                 bch2_quota_acct(c, inode->ei_qid, Q_INO, -1,
1578                                 KEY_TYPE_QUOTA_WARN);
1579                 bch2_inode_rm(c, inode_inum(inode));
1580         }
1581
1582         mutex_lock(&c->vfs_inodes_lock);
1583         list_del_init(&inode->ei_vfs_inode_list);
1584         mutex_unlock(&c->vfs_inodes_lock);
1585 }
1586
1587 void bch2_evict_subvolume_inodes(struct bch_fs *c, snapshot_id_list *s)
1588 {
1589         struct bch_inode_info *inode;
1590         DARRAY(struct bch_inode_info *) grabbed;
1591         bool clean_pass = false, this_pass_clean;
1592
1593         /*
1594          * Initially, we scan for inodes without I_DONTCACHE, then mark them to
1595          * be pruned with d_mark_dontcache().
1596          *
1597          * Once we've had a clean pass where we didn't find any inodes without
1598          * I_DONTCACHE, we wait for them to be freed:
1599          */
1600
1601         darray_init(&grabbed);
1602         darray_make_room(&grabbed, 1024);
1603 again:
1604         cond_resched();
1605         this_pass_clean = true;
1606
1607         mutex_lock(&c->vfs_inodes_lock);
1608         list_for_each_entry(inode, &c->vfs_inodes_list, ei_vfs_inode_list) {
1609                 if (!snapshot_list_has_id(s, inode->ei_subvol))
1610                         continue;
1611
1612                 if (!(inode->v.i_state & I_DONTCACHE) &&
1613                     !(inode->v.i_state & I_FREEING) &&
1614                     igrab(&inode->v)) {
1615                         this_pass_clean = false;
1616
1617                         if (darray_push_gfp(&grabbed, inode, GFP_ATOMIC|__GFP_NOWARN)) {
1618                                 iput(&inode->v);
1619                                 break;
1620                         }
1621                 } else if (clean_pass && this_pass_clean) {
1622                         wait_queue_head_t *wq = bit_waitqueue(&inode->v.i_state, __I_NEW);
1623                         DEFINE_WAIT_BIT(wait, &inode->v.i_state, __I_NEW);
1624
1625                         prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
1626                         mutex_unlock(&c->vfs_inodes_lock);
1627
1628                         schedule();
1629                         finish_wait(wq, &wait.wq_entry);
1630                         goto again;
1631                 }
1632         }
1633         mutex_unlock(&c->vfs_inodes_lock);
1634
1635         darray_for_each(grabbed, i) {
1636                 inode = *i;
1637                 d_mark_dontcache(&inode->v);
1638                 d_prune_aliases(&inode->v);
1639                 iput(&inode->v);
1640         }
1641         grabbed.nr = 0;
1642
1643         if (!clean_pass || !this_pass_clean) {
1644                 clean_pass = this_pass_clean;
1645                 goto again;
1646         }
1647
1648         darray_exit(&grabbed);
1649 }
1650
1651 static int bch2_statfs(struct dentry *dentry, struct kstatfs *buf)
1652 {
1653         struct super_block *sb = dentry->d_sb;
1654         struct bch_fs *c = sb->s_fs_info;
1655         struct bch_fs_usage_short usage = bch2_fs_usage_read_short(c);
1656         unsigned shift = sb->s_blocksize_bits - 9;
1657         /*
1658          * this assumes inodes take up 64 bytes, which is a decent average
1659          * number:
1660          */
1661         u64 avail_inodes = ((usage.capacity - usage.used) << 3);
1662
1663         buf->f_type     = BCACHEFS_STATFS_MAGIC;
1664         buf->f_bsize    = sb->s_blocksize;
1665         buf->f_blocks   = usage.capacity >> shift;
1666         buf->f_bfree    = usage.free >> shift;
1667         buf->f_bavail   = avail_factor(usage.free) >> shift;
1668
1669         buf->f_files    = usage.nr_inodes + avail_inodes;
1670         buf->f_ffree    = avail_inodes;
1671
1672         buf->f_fsid     = uuid_to_fsid(c->sb.user_uuid.b);
1673         buf->f_namelen  = BCH_NAME_MAX;
1674
1675         return 0;
1676 }
1677
1678 static int bch2_sync_fs(struct super_block *sb, int wait)
1679 {
1680         struct bch_fs *c = sb->s_fs_info;
1681         int ret;
1682
1683         if (c->opts.journal_flush_disabled)
1684                 return 0;
1685
1686         if (!wait) {
1687                 bch2_journal_flush_async(&c->journal, NULL);
1688                 return 0;
1689         }
1690
1691         ret = bch2_journal_flush(&c->journal);
1692         return bch2_err_class(ret);
1693 }
1694
1695 static struct bch_fs *bch2_path_to_fs(const char *path)
1696 {
1697         struct bch_fs *c;
1698         dev_t dev;
1699         int ret;
1700
1701         ret = lookup_bdev(path, &dev);
1702         if (ret)
1703                 return ERR_PTR(ret);
1704
1705         c = bch2_dev_to_fs(dev);
1706         if (c)
1707                 closure_put(&c->cl);
1708         return c ?: ERR_PTR(-ENOENT);
1709 }
1710
1711 static int bch2_remount(struct super_block *sb, int *flags, char *data)
1712 {
1713         struct bch_fs *c = sb->s_fs_info;
1714         struct bch_opts opts = bch2_opts_empty();
1715         int ret;
1716
1717         ret = bch2_parse_mount_opts(c, &opts, data);
1718         if (ret)
1719                 goto err;
1720
1721         opt_set(opts, read_only, (*flags & SB_RDONLY) != 0);
1722
1723         if (opts.read_only != c->opts.read_only) {
1724                 down_write(&c->state_lock);
1725
1726                 if (opts.read_only) {
1727                         bch2_fs_read_only(c);
1728
1729                         sb->s_flags |= SB_RDONLY;
1730                 } else {
1731                         ret = bch2_fs_read_write(c);
1732                         if (ret) {
1733                                 bch_err(c, "error going rw: %i", ret);
1734                                 up_write(&c->state_lock);
1735                                 ret = -EINVAL;
1736                                 goto err;
1737                         }
1738
1739                         sb->s_flags &= ~SB_RDONLY;
1740                 }
1741
1742                 c->opts.read_only = opts.read_only;
1743
1744                 up_write(&c->state_lock);
1745         }
1746
1747         if (opt_defined(opts, errors))
1748                 c->opts.errors = opts.errors;
1749 err:
1750         return bch2_err_class(ret);
1751 }
1752
1753 static int bch2_show_devname(struct seq_file *seq, struct dentry *root)
1754 {
1755         struct bch_fs *c = root->d_sb->s_fs_info;
1756         bool first = true;
1757
1758         for_each_online_member(c, ca) {
1759                 if (!first)
1760                         seq_putc(seq, ':');
1761                 first = false;
1762                 seq_puts(seq, ca->disk_sb.sb_name);
1763         }
1764
1765         return 0;
1766 }
1767
1768 static int bch2_show_options(struct seq_file *seq, struct dentry *root)
1769 {
1770         struct bch_fs *c = root->d_sb->s_fs_info;
1771         enum bch_opt_id i;
1772         struct printbuf buf = PRINTBUF;
1773         int ret = 0;
1774
1775         for (i = 0; i < bch2_opts_nr; i++) {
1776                 const struct bch_option *opt = &bch2_opt_table[i];
1777                 u64 v = bch2_opt_get_by_id(&c->opts, i);
1778
1779                 if (!(opt->flags & OPT_MOUNT))
1780                         continue;
1781
1782                 if (v == bch2_opt_get_by_id(&bch2_opts_default, i))
1783                         continue;
1784
1785                 printbuf_reset(&buf);
1786                 bch2_opt_to_text(&buf, c, c->disk_sb.sb, opt, v,
1787                                  OPT_SHOW_MOUNT_STYLE);
1788                 seq_putc(seq, ',');
1789                 seq_puts(seq, buf.buf);
1790         }
1791
1792         if (buf.allocation_failure)
1793                 ret = -ENOMEM;
1794         printbuf_exit(&buf);
1795         return ret;
1796 }
1797
1798 static void bch2_put_super(struct super_block *sb)
1799 {
1800         struct bch_fs *c = sb->s_fs_info;
1801
1802         __bch2_fs_stop(c);
1803 }
1804
1805 /*
1806  * bcachefs doesn't currently integrate intwrite freeze protection but the
1807  * internal write references serve the same purpose. Therefore reuse the
1808  * read-only transition code to perform the quiesce. The caveat is that we don't
1809  * currently have the ability to block tasks that want a write reference while
1810  * the superblock is frozen. This is fine for now, but we should either add
1811  * blocking support or find a way to integrate sb_start_intwrite() and friends.
1812  */
1813 static int bch2_freeze(struct super_block *sb)
1814 {
1815         struct bch_fs *c = sb->s_fs_info;
1816
1817         down_write(&c->state_lock);
1818         bch2_fs_read_only(c);
1819         up_write(&c->state_lock);
1820         return 0;
1821 }
1822
1823 static int bch2_unfreeze(struct super_block *sb)
1824 {
1825         struct bch_fs *c = sb->s_fs_info;
1826         int ret;
1827
1828         if (test_bit(BCH_FS_emergency_ro, &c->flags))
1829                 return 0;
1830
1831         down_write(&c->state_lock);
1832         ret = bch2_fs_read_write(c);
1833         up_write(&c->state_lock);
1834         return ret;
1835 }
1836
1837 static const struct super_operations bch_super_operations = {
1838         .alloc_inode    = bch2_alloc_inode,
1839         .free_inode     = bch2_free_inode,
1840         .write_inode    = bch2_vfs_write_inode,
1841         .evict_inode    = bch2_evict_inode,
1842         .sync_fs        = bch2_sync_fs,
1843         .statfs         = bch2_statfs,
1844         .show_devname   = bch2_show_devname,
1845         .show_options   = bch2_show_options,
1846         .remount_fs     = bch2_remount,
1847         .put_super      = bch2_put_super,
1848         .freeze_fs      = bch2_freeze,
1849         .unfreeze_fs    = bch2_unfreeze,
1850 };
1851
1852 static int bch2_set_super(struct super_block *s, void *data)
1853 {
1854         s->s_fs_info = data;
1855         return 0;
1856 }
1857
1858 static int bch2_noset_super(struct super_block *s, void *data)
1859 {
1860         return -EBUSY;
1861 }
1862
1863 typedef DARRAY(struct bch_fs *) darray_fs;
1864
1865 static int bch2_test_super(struct super_block *s, void *data)
1866 {
1867         struct bch_fs *c = s->s_fs_info;
1868         darray_fs *d = data;
1869
1870         if (!c)
1871                 return false;
1872
1873         darray_for_each(*d, i)
1874                 if (c != *i)
1875                         return false;
1876         return true;
1877 }
1878
1879 static struct dentry *bch2_mount(struct file_system_type *fs_type,
1880                                  int flags, const char *dev_name, void *data)
1881 {
1882         struct bch_fs *c;
1883         struct super_block *sb;
1884         struct inode *vinode;
1885         struct bch_opts opts = bch2_opts_empty();
1886         int ret;
1887
1888         opt_set(opts, read_only, (flags & SB_RDONLY) != 0);
1889
1890         ret = bch2_parse_mount_opts(NULL, &opts, data);
1891         if (ret) {
1892                 ret = bch2_err_class(ret);
1893                 return ERR_PTR(ret);
1894         }
1895
1896         if (!dev_name || strlen(dev_name) == 0)
1897                 return ERR_PTR(-EINVAL);
1898
1899         darray_str devs;
1900         ret = bch2_split_devs(dev_name, &devs);
1901         if (ret)
1902                 return ERR_PTR(ret);
1903
1904         darray_fs devs_to_fs = {};
1905         darray_for_each(devs, i) {
1906                 ret = darray_push(&devs_to_fs, bch2_path_to_fs(*i));
1907                 if (ret) {
1908                         sb = ERR_PTR(ret);
1909                         goto got_sb;
1910                 }
1911         }
1912
1913         sb = sget(fs_type, bch2_test_super, bch2_noset_super, flags|SB_NOSEC, &devs_to_fs);
1914         if (!IS_ERR(sb))
1915                 goto got_sb;
1916
1917         c = bch2_fs_open(devs.data, devs.nr, opts);
1918         if (IS_ERR(c)) {
1919                 sb = ERR_CAST(c);
1920                 goto got_sb;
1921         }
1922
1923         /* Some options can't be parsed until after the fs is started: */
1924         ret = bch2_parse_mount_opts(c, &opts, data);
1925         if (ret) {
1926                 bch2_fs_stop(c);
1927                 sb = ERR_PTR(ret);
1928                 goto got_sb;
1929         }
1930
1931         bch2_opts_apply(&c->opts, opts);
1932
1933         sb = sget(fs_type, NULL, bch2_set_super, flags|SB_NOSEC, c);
1934         if (IS_ERR(sb))
1935                 bch2_fs_stop(c);
1936 got_sb:
1937         darray_exit(&devs_to_fs);
1938         bch2_darray_str_exit(&devs);
1939
1940         if (IS_ERR(sb)) {
1941                 ret = PTR_ERR(sb);
1942                 ret = bch2_err_class(ret);
1943                 return ERR_PTR(ret);
1944         }
1945
1946         c = sb->s_fs_info;
1947
1948         if (sb->s_root) {
1949                 if ((flags ^ sb->s_flags) & SB_RDONLY) {
1950                         ret = -EBUSY;
1951                         goto err_put_super;
1952                 }
1953                 goto out;
1954         }
1955
1956         sb->s_blocksize         = block_bytes(c);
1957         sb->s_blocksize_bits    = ilog2(block_bytes(c));
1958         sb->s_maxbytes          = MAX_LFS_FILESIZE;
1959         sb->s_op                = &bch_super_operations;
1960         sb->s_export_op         = &bch_export_ops;
1961 #ifdef CONFIG_BCACHEFS_QUOTA
1962         sb->s_qcop              = &bch2_quotactl_operations;
1963         sb->s_quota_types       = QTYPE_MASK_USR|QTYPE_MASK_GRP|QTYPE_MASK_PRJ;
1964 #endif
1965         sb->s_xattr             = bch2_xattr_handlers;
1966         sb->s_magic             = BCACHEFS_STATFS_MAGIC;
1967         sb->s_time_gran         = c->sb.nsec_per_time_unit;
1968         sb->s_time_min          = div_s64(S64_MIN, c->sb.time_units_per_sec) + 1;
1969         sb->s_time_max          = div_s64(S64_MAX, c->sb.time_units_per_sec);
1970         sb->s_uuid              = c->sb.user_uuid;
1971         c->vfs_sb               = sb;
1972         strscpy(sb->s_id, c->name, sizeof(sb->s_id));
1973
1974         ret = super_setup_bdi(sb);
1975         if (ret)
1976                 goto err_put_super;
1977
1978         sb->s_bdi->ra_pages             = VM_READAHEAD_PAGES;
1979
1980         for_each_online_member(c, ca) {
1981                 struct block_device *bdev = ca->disk_sb.bdev;
1982
1983                 /* XXX: create an anonymous device for multi device filesystems */
1984                 sb->s_bdev      = bdev;
1985                 sb->s_dev       = bdev->bd_dev;
1986                 percpu_ref_put(&ca->io_ref);
1987                 break;
1988         }
1989
1990         c->dev = sb->s_dev;
1991
1992 #ifdef CONFIG_BCACHEFS_POSIX_ACL
1993         if (c->opts.acl)
1994                 sb->s_flags     |= SB_POSIXACL;
1995 #endif
1996
1997         sb->s_shrink->seeks = 0;
1998
1999         vinode = bch2_vfs_inode_get(c, BCACHEFS_ROOT_SUBVOL_INUM);
2000         ret = PTR_ERR_OR_ZERO(vinode);
2001         bch_err_msg(c, ret, "mounting: error getting root inode");
2002         if (ret)
2003                 goto err_put_super;
2004
2005         sb->s_root = d_make_root(vinode);
2006         if (!sb->s_root) {
2007                 bch_err(c, "error mounting: error allocating root dentry");
2008                 ret = -ENOMEM;
2009                 goto err_put_super;
2010         }
2011
2012         sb->s_flags |= SB_ACTIVE;
2013 out:
2014         return dget(sb->s_root);
2015
2016 err_put_super:
2017         __bch2_fs_stop(c);
2018         deactivate_locked_super(sb);
2019         return ERR_PTR(bch2_err_class(ret));
2020 }
2021
2022 static void bch2_kill_sb(struct super_block *sb)
2023 {
2024         struct bch_fs *c = sb->s_fs_info;
2025
2026         generic_shutdown_super(sb);
2027         bch2_fs_free(c);
2028 }
2029
2030 static struct file_system_type bcache_fs_type = {
2031         .owner          = THIS_MODULE,
2032         .name           = "bcachefs",
2033         .mount          = bch2_mount,
2034         .kill_sb        = bch2_kill_sb,
2035         .fs_flags       = FS_REQUIRES_DEV,
2036 };
2037
2038 MODULE_ALIAS_FS("bcachefs");
2039
2040 void bch2_vfs_exit(void)
2041 {
2042         unregister_filesystem(&bcache_fs_type);
2043         kmem_cache_destroy(bch2_inode_cache);
2044 }
2045
2046 int __init bch2_vfs_init(void)
2047 {
2048         int ret = -ENOMEM;
2049
2050         bch2_inode_cache = KMEM_CACHE(bch_inode_info, SLAB_RECLAIM_ACCOUNT);
2051         if (!bch2_inode_cache)
2052                 goto err;
2053
2054         ret = register_filesystem(&bcache_fs_type);
2055         if (ret)
2056                 goto err;
2057
2058         return 0;
2059 err:
2060         bch2_vfs_exit();
2061         return ret;
2062 }
2063
2064 #endif /* NO_BCACHEFS_FS */