1 // SPDX-License-Identifier: GPL-2.0
5 #include "bkey_methods.h"
6 #include "btree_update.h"
12 #include "subvolume.h"
14 #include <linux/dcache.h>
16 static unsigned bch2_dirent_name_bytes(struct bkey_s_c_dirent d)
18 unsigned bkey_u64s = bkey_val_u64s(d.k);
19 unsigned bkey_bytes = bkey_u64s * sizeof(u64);
20 u64 last_u64 = ((u64*)d.v)[bkey_u64s - 1];
22 unsigned trailing_nuls = last_u64 ? __builtin_ctzll(last_u64) / 8 : 64 / 8;
24 unsigned trailing_nuls = last_u64 ? __builtin_clzll(last_u64) / 8 : 64 / 8;
28 offsetof(struct bch_dirent, d_name) -
32 struct qstr bch2_dirent_get_name(struct bkey_s_c_dirent d)
34 return (struct qstr) QSTR_INIT(d.v->d_name, bch2_dirent_name_bytes(d));
37 static u64 bch2_dirent_hash(const struct bch_hash_info *info,
38 const struct qstr *name)
40 struct bch_str_hash_ctx ctx;
42 bch2_str_hash_init(&ctx, info);
43 bch2_str_hash_update(&ctx, info, name->name, name->len);
45 /* [0,2) reserved for dots */
46 return max_t(u64, bch2_str_hash_end(&ctx, info), 2);
49 static u64 dirent_hash_key(const struct bch_hash_info *info, const void *key)
51 return bch2_dirent_hash(info, key);
54 static u64 dirent_hash_bkey(const struct bch_hash_info *info, struct bkey_s_c k)
56 struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
57 struct qstr name = bch2_dirent_get_name(d);
59 return bch2_dirent_hash(info, &name);
62 static bool dirent_cmp_key(struct bkey_s_c _l, const void *_r)
64 struct bkey_s_c_dirent l = bkey_s_c_to_dirent(_l);
65 const struct qstr l_name = bch2_dirent_get_name(l);
66 const struct qstr *r_name = _r;
68 return !qstr_eq(l_name, *r_name);
71 static bool dirent_cmp_bkey(struct bkey_s_c _l, struct bkey_s_c _r)
73 struct bkey_s_c_dirent l = bkey_s_c_to_dirent(_l);
74 struct bkey_s_c_dirent r = bkey_s_c_to_dirent(_r);
75 const struct qstr l_name = bch2_dirent_get_name(l);
76 const struct qstr r_name = bch2_dirent_get_name(r);
78 return !qstr_eq(l_name, r_name);
81 static bool dirent_is_visible(subvol_inum inum, struct bkey_s_c k)
83 struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
85 if (d.v->d_type == DT_SUBVOL)
86 return le32_to_cpu(d.v->d_parent_subvol) == inum.subvol;
90 const struct bch_hash_desc bch2_dirent_hash_desc = {
91 .btree_id = BTREE_ID_dirents,
92 .key_type = KEY_TYPE_dirent,
93 .hash_key = dirent_hash_key,
94 .hash_bkey = dirent_hash_bkey,
95 .cmp_key = dirent_cmp_key,
96 .cmp_bkey = dirent_cmp_bkey,
97 .is_visible = dirent_is_visible,
100 int bch2_dirent_invalid(struct bch_fs *c, struct bkey_s_c k,
101 enum bkey_invalid_flags flags,
102 struct printbuf *err)
104 struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
105 struct qstr d_name = bch2_dirent_get_name(d);
108 bkey_fsck_err_on(!d_name.len, c, err,
112 bkey_fsck_err_on(bkey_val_u64s(k.k) > dirent_val_u64s(d_name.len), c, err,
114 "value too big (%zu > %u)",
115 bkey_val_u64s(k.k), dirent_val_u64s(d_name.len));
118 * Check new keys don't exceed the max length
119 * (older keys may be larger.)
121 bkey_fsck_err_on((flags & BKEY_INVALID_COMMIT) && d_name.len > BCH_NAME_MAX, c, err,
122 dirent_name_too_long,
123 "dirent name too big (%u > %u)",
124 d_name.len, BCH_NAME_MAX);
126 bkey_fsck_err_on(d_name.len != strnlen(d_name.name, d_name.len), c, err,
127 dirent_name_embedded_nul,
128 "dirent has stray data after name's NUL");
130 bkey_fsck_err_on((d_name.len == 1 && !memcmp(d_name.name, ".", 1)) ||
131 (d_name.len == 2 && !memcmp(d_name.name, "..", 2)), c, err,
132 dirent_name_dot_or_dotdot,
135 bkey_fsck_err_on(memchr(d_name.name, '/', d_name.len), c, err,
136 dirent_name_has_slash,
139 bkey_fsck_err_on(d.v->d_type != DT_SUBVOL &&
140 le64_to_cpu(d.v->d_inum) == d.k->p.inode, c, err,
142 "dirent points to own directory");
147 void bch2_dirent_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c k)
149 struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
150 struct qstr d_name = bch2_dirent_get_name(d);
152 prt_printf(out, "%.*s -> ", d_name.len, d_name.name);
154 if (d.v->d_type != DT_SUBVOL)
155 prt_printf(out, "%llu", le64_to_cpu(d.v->d_inum));
157 prt_printf(out, "%u -> %u",
158 le32_to_cpu(d.v->d_parent_subvol),
159 le32_to_cpu(d.v->d_child_subvol));
161 prt_printf(out, " type %s", bch2_d_type_str(d.v->d_type));
164 static struct bkey_i_dirent *dirent_create_key(struct btree_trans *trans,
165 subvol_inum dir, u8 type,
166 const struct qstr *name, u64 dst)
168 struct bkey_i_dirent *dirent;
169 unsigned u64s = BKEY_U64s + dirent_val_u64s(name->len);
171 if (name->len > BCH_NAME_MAX)
172 return ERR_PTR(-ENAMETOOLONG);
174 BUG_ON(u64s > U8_MAX);
176 dirent = bch2_trans_kmalloc(trans, u64s * sizeof(u64));
180 bkey_dirent_init(&dirent->k_i);
181 dirent->k.u64s = u64s;
183 if (type != DT_SUBVOL) {
184 dirent->v.d_inum = cpu_to_le64(dst);
186 dirent->v.d_parent_subvol = cpu_to_le32(dir.subvol);
187 dirent->v.d_child_subvol = cpu_to_le32(dst);
190 dirent->v.d_type = type;
192 memcpy(dirent->v.d_name, name->name, name->len);
193 memset(dirent->v.d_name + name->len, 0,
194 bkey_val_bytes(&dirent->k) -
195 offsetof(struct bch_dirent, d_name) -
198 EBUG_ON(bch2_dirent_name_bytes(dirent_i_to_s_c(dirent)) != name->len);
203 int bch2_dirent_create_snapshot(struct btree_trans *trans,
204 u64 dir, u32 snapshot,
205 const struct bch_hash_info *hash_info,
206 u8 type, const struct qstr *name, u64 dst_inum,
208 bch_str_hash_flags_t str_hash_flags)
210 subvol_inum zero_inum = { 0 };
211 struct bkey_i_dirent *dirent;
214 dirent = dirent_create_key(trans, zero_inum, type, name, dst_inum);
215 ret = PTR_ERR_OR_ZERO(dirent);
219 dirent->k.p.inode = dir;
220 dirent->k.p.snapshot = snapshot;
222 ret = bch2_hash_set_snapshot(trans, bch2_dirent_hash_desc, hash_info,
224 &dirent->k_i, str_hash_flags,
225 BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
226 *dir_offset = dirent->k.p.offset;
231 int bch2_dirent_create(struct btree_trans *trans, subvol_inum dir,
232 const struct bch_hash_info *hash_info,
233 u8 type, const struct qstr *name, u64 dst_inum,
235 bch_str_hash_flags_t str_hash_flags)
237 struct bkey_i_dirent *dirent;
240 dirent = dirent_create_key(trans, dir, type, name, dst_inum);
241 ret = PTR_ERR_OR_ZERO(dirent);
245 ret = bch2_hash_set(trans, bch2_dirent_hash_desc, hash_info,
246 dir, &dirent->k_i, str_hash_flags);
247 *dir_offset = dirent->k.p.offset;
252 static void dirent_copy_target(struct bkey_i_dirent *dst,
253 struct bkey_s_c_dirent src)
255 dst->v.d_inum = src.v->d_inum;
256 dst->v.d_type = src.v->d_type;
259 int bch2_dirent_read_target(struct btree_trans *trans, subvol_inum dir,
260 struct bkey_s_c_dirent d, subvol_inum *target)
262 struct bch_subvolume s;
265 if (d.v->d_type == DT_SUBVOL &&
266 le32_to_cpu(d.v->d_parent_subvol) != dir.subvol)
269 if (likely(d.v->d_type != DT_SUBVOL)) {
270 target->subvol = dir.subvol;
271 target->inum = le64_to_cpu(d.v->d_inum);
273 target->subvol = le32_to_cpu(d.v->d_child_subvol);
275 ret = bch2_subvolume_get(trans, target->subvol, true, BTREE_ITER_CACHED, &s);
277 target->inum = le64_to_cpu(s.inode);
283 int bch2_dirent_rename(struct btree_trans *trans,
284 subvol_inum src_dir, struct bch_hash_info *src_hash,
285 subvol_inum dst_dir, struct bch_hash_info *dst_hash,
286 const struct qstr *src_name, subvol_inum *src_inum, u64 *src_offset,
287 const struct qstr *dst_name, subvol_inum *dst_inum, u64 *dst_offset,
288 enum bch_rename_mode mode)
290 struct btree_iter src_iter = { NULL };
291 struct btree_iter dst_iter = { NULL };
292 struct bkey_s_c old_src, old_dst = bkey_s_c_null;
293 struct bkey_i_dirent *new_src = NULL, *new_dst = NULL;
294 struct bpos dst_pos =
295 POS(dst_dir.inum, bch2_dirent_hash(dst_hash, dst_name));
296 unsigned src_type = 0, dst_type = 0, src_update_flags = 0;
299 if (src_dir.subvol != dst_dir.subvol)
302 memset(src_inum, 0, sizeof(*src_inum));
303 memset(dst_inum, 0, sizeof(*dst_inum));
306 ret = bch2_hash_lookup(trans, &src_iter, bch2_dirent_hash_desc,
307 src_hash, src_dir, src_name,
312 old_src = bch2_btree_iter_peek_slot(&src_iter);
313 ret = bkey_err(old_src);
317 ret = bch2_dirent_read_target(trans, src_dir,
318 bkey_s_c_to_dirent(old_src), src_inum);
322 src_type = bkey_s_c_to_dirent(old_src).v->d_type;
324 if (src_type == DT_SUBVOL && mode == BCH_RENAME_EXCHANGE)
329 if (mode == BCH_RENAME) {
331 * Note that we're _not_ checking if the target already exists -
332 * we're relying on the VFS to do that check for us for
335 ret = bch2_hash_hole(trans, &dst_iter, bch2_dirent_hash_desc,
336 dst_hash, dst_dir, dst_name);
340 ret = bch2_hash_lookup(trans, &dst_iter, bch2_dirent_hash_desc,
341 dst_hash, dst_dir, dst_name,
346 old_dst = bch2_btree_iter_peek_slot(&dst_iter);
347 ret = bkey_err(old_dst);
351 ret = bch2_dirent_read_target(trans, dst_dir,
352 bkey_s_c_to_dirent(old_dst), dst_inum);
356 dst_type = bkey_s_c_to_dirent(old_dst).v->d_type;
358 if (dst_type == DT_SUBVOL)
362 if (mode != BCH_RENAME_EXCHANGE)
363 *src_offset = dst_iter.pos.offset;
365 /* Create new dst key: */
366 new_dst = dirent_create_key(trans, dst_dir, 0, dst_name, 0);
367 ret = PTR_ERR_OR_ZERO(new_dst);
371 dirent_copy_target(new_dst, bkey_s_c_to_dirent(old_src));
372 new_dst->k.p = dst_iter.pos;
374 /* Create new src key: */
375 if (mode == BCH_RENAME_EXCHANGE) {
376 new_src = dirent_create_key(trans, src_dir, 0, src_name, 0);
377 ret = PTR_ERR_OR_ZERO(new_src);
381 dirent_copy_target(new_src, bkey_s_c_to_dirent(old_dst));
382 new_src->k.p = src_iter.pos;
384 new_src = bch2_trans_kmalloc(trans, sizeof(struct bkey_i));
385 ret = PTR_ERR_OR_ZERO(new_src);
389 bkey_init(&new_src->k);
390 new_src->k.p = src_iter.pos;
392 if (bkey_le(dst_pos, src_iter.pos) &&
393 bkey_lt(src_iter.pos, dst_iter.pos)) {
395 * We have a hash collision for the new dst key,
396 * and new_src - the key we're deleting - is between
397 * new_dst's hashed slot and the slot we're going to be
398 * inserting it into - oops. This will break the hash
399 * table if we don't deal with it:
401 if (mode == BCH_RENAME) {
403 * If we're not overwriting, we can just insert
404 * new_dst at the src position:
407 new_src->k.p = src_iter.pos;
410 /* If we're overwriting, we can't insert new_dst
411 * at a different slot because it has to
412 * overwrite old_dst - just make sure to use a
413 * whiteout when deleting src:
415 new_src->k.type = KEY_TYPE_hash_whiteout;
418 /* Check if we need a whiteout to delete src: */
419 ret = bch2_hash_needs_whiteout(trans, bch2_dirent_hash_desc,
420 src_hash, &src_iter);
425 new_src->k.type = KEY_TYPE_hash_whiteout;
429 ret = bch2_trans_update(trans, &dst_iter, &new_dst->k_i, 0);
435 * If we're deleting a subvolume, we need to really delete the dirent,
436 * not just emit a whiteout in the current snapshot:
438 if (src_type == DT_SUBVOL) {
439 bch2_btree_iter_set_snapshot(&src_iter, old_src.k->p.snapshot);
440 ret = bch2_btree_iter_traverse(&src_iter);
444 new_src->k.p = src_iter.pos;
445 src_update_flags |= BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE;
448 ret = bch2_trans_update(trans, &src_iter, &new_src->k_i, src_update_flags);
452 if (mode == BCH_RENAME_EXCHANGE)
453 *src_offset = new_src->k.p.offset;
454 *dst_offset = new_dst->k.p.offset;
456 bch2_trans_iter_exit(trans, &src_iter);
457 bch2_trans_iter_exit(trans, &dst_iter);
461 int __bch2_dirent_lookup_trans(struct btree_trans *trans,
462 struct btree_iter *iter,
464 const struct bch_hash_info *hash_info,
465 const struct qstr *name, subvol_inum *inum,
469 struct bkey_s_c_dirent d;
473 ret = bch2_subvolume_get_snapshot(trans, dir.subvol, &snapshot);
477 ret = bch2_hash_lookup(trans, iter, bch2_dirent_hash_desc,
478 hash_info, dir, name, flags);
482 k = bch2_btree_iter_peek_slot(iter);
487 d = bkey_s_c_to_dirent(k);
489 ret = bch2_dirent_read_target(trans, dir, d, inum);
494 bch2_trans_iter_exit(trans, iter);
499 u64 bch2_dirent_lookup(struct bch_fs *c, subvol_inum dir,
500 const struct bch_hash_info *hash_info,
501 const struct qstr *name, subvol_inum *inum)
503 struct btree_trans *trans = bch2_trans_get(c);
504 struct btree_iter iter = { NULL };
506 int ret = lockrestart_do(trans,
507 __bch2_dirent_lookup_trans(trans, &iter, dir, hash_info, name, inum, 0));
508 bch2_trans_iter_exit(trans, &iter);
509 bch2_trans_put(trans);
513 int bch2_empty_dir_snapshot(struct btree_trans *trans, u64 dir, u32 snapshot)
515 struct btree_iter iter;
519 for_each_btree_key_upto_norestart(trans, iter, BTREE_ID_dirents,
520 SPOS(dir, 0, snapshot),
521 POS(dir, U64_MAX), 0, k, ret)
522 if (k.k->type == KEY_TYPE_dirent) {
526 bch2_trans_iter_exit(trans, &iter);
531 int bch2_empty_dir_trans(struct btree_trans *trans, subvol_inum dir)
535 return bch2_subvolume_get_snapshot(trans, dir.subvol, &snapshot) ?:
536 bch2_empty_dir_snapshot(trans, dir.inum, snapshot);
539 int bch2_readdir(struct bch_fs *c, subvol_inum inum, struct dir_context *ctx)
541 struct btree_trans *trans = bch2_trans_get(c);
542 struct btree_iter iter;
544 struct bkey_s_c_dirent dirent;
551 bch2_bkey_buf_init(&sk);
553 bch2_trans_begin(trans);
555 ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
559 for_each_btree_key_upto_norestart(trans, iter, BTREE_ID_dirents,
560 SPOS(inum.inum, ctx->pos, snapshot),
561 POS(inum.inum, U64_MAX), 0, k, ret) {
562 if (k.k->type != KEY_TYPE_dirent)
565 dirent = bkey_s_c_to_dirent(k);
567 ret = bch2_dirent_read_target(trans, inum, dirent, &target);
573 /* dir_emit() can fault and block: */
574 bch2_bkey_buf_reassemble(&sk, c, k);
575 dirent = bkey_i_to_s_c_dirent(sk.k);
576 bch2_trans_unlock(trans);
578 name = bch2_dirent_get_name(dirent);
580 ctx->pos = dirent.k->p.offset;
581 if (!dir_emit(ctx, name.name,
584 vfs_d_type(dirent.v->d_type)))
586 ctx->pos = dirent.k->p.offset + 1;
589 * read_target looks up subvolumes, we can overflow paths if the
590 * directory has many subvolumes in it
592 ret = btree_trans_too_many_iters(trans);
596 bch2_trans_iter_exit(trans, &iter);
598 if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
601 bch2_trans_put(trans);
602 bch2_bkey_buf_exit(&sk, c);