1 // SPDX-License-Identifier: GPL-2.0
4 #include "bkey_methods.h"
5 #include "btree_update.h"
12 #include <linux/dcache.h>
14 unsigned bch2_dirent_name_bytes(struct bkey_s_c_dirent d)
16 unsigned len = bkey_val_bytes(d.k) -
17 offsetof(struct bch_dirent, d_name);
19 return strnlen(d.v->d_name, len);
22 static u64 bch2_dirent_hash(const struct bch_hash_info *info,
23 const struct qstr *name)
25 struct bch_str_hash_ctx ctx;
27 bch2_str_hash_init(&ctx, info);
28 bch2_str_hash_update(&ctx, info, name->name, name->len);
30 /* [0,2) reserved for dots */
31 return max_t(u64, bch2_str_hash_end(&ctx, info), 2);
34 static u64 dirent_hash_key(const struct bch_hash_info *info, const void *key)
36 return bch2_dirent_hash(info, key);
39 static u64 dirent_hash_bkey(const struct bch_hash_info *info, struct bkey_s_c k)
41 struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
42 struct qstr name = QSTR_INIT(d.v->d_name, bch2_dirent_name_bytes(d));
44 return bch2_dirent_hash(info, &name);
47 static bool dirent_cmp_key(struct bkey_s_c _l, const void *_r)
49 struct bkey_s_c_dirent l = bkey_s_c_to_dirent(_l);
50 int len = bch2_dirent_name_bytes(l);
51 const struct qstr *r = _r;
53 return len - r->len ?: memcmp(l.v->d_name, r->name, len);
56 static bool dirent_cmp_bkey(struct bkey_s_c _l, struct bkey_s_c _r)
58 struct bkey_s_c_dirent l = bkey_s_c_to_dirent(_l);
59 struct bkey_s_c_dirent r = bkey_s_c_to_dirent(_r);
60 int l_len = bch2_dirent_name_bytes(l);
61 int r_len = bch2_dirent_name_bytes(r);
63 return l_len - r_len ?: memcmp(l.v->d_name, r.v->d_name, l_len);
66 const struct bch_hash_desc bch2_dirent_hash_desc = {
67 .btree_id = BTREE_ID_DIRENTS,
68 .key_type = KEY_TYPE_dirent,
69 .hash_key = dirent_hash_key,
70 .hash_bkey = dirent_hash_bkey,
71 .cmp_key = dirent_cmp_key,
72 .cmp_bkey = dirent_cmp_bkey,
75 const char *bch2_dirent_invalid(const struct bch_fs *c, struct bkey_s_c k)
77 struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
80 if (bkey_val_bytes(k.k) < sizeof(struct bch_dirent))
81 return "value too small";
83 len = bch2_dirent_name_bytes(d);
88 * older versions of bcachefs were buggy and creating dirent
89 * keys that were bigger than necessary:
91 if (bkey_val_u64s(k.k) > dirent_val_u64s(len + 7))
92 return "value too big";
94 if (len > BCH_NAME_MAX)
95 return "dirent name too big";
100 void bch2_dirent_to_text(struct printbuf *out, struct bch_fs *c,
103 struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
105 bch_scnmemcpy(out, d.v->d_name,
106 bch2_dirent_name_bytes(d));
107 pr_buf(out, " -> %llu type %u", d.v->d_inum, d.v->d_type);
110 static struct bkey_i_dirent *dirent_create_key(struct btree_trans *trans,
111 u8 type, const struct qstr *name, u64 dst)
113 struct bkey_i_dirent *dirent;
114 unsigned u64s = BKEY_U64s + dirent_val_u64s(name->len);
116 if (name->len > BCH_NAME_MAX)
117 return ERR_PTR(-ENAMETOOLONG);
119 BUG_ON(u64s > U8_MAX);
121 dirent = bch2_trans_kmalloc(trans, u64s * sizeof(u64));
125 bkey_dirent_init(&dirent->k_i);
126 dirent->k.u64s = u64s;
127 dirent->v.d_inum = cpu_to_le64(dst);
128 dirent->v.d_type = type;
130 memcpy(dirent->v.d_name, name->name, name->len);
131 memset(dirent->v.d_name + name->len, 0,
132 bkey_val_bytes(&dirent->k) -
133 offsetof(struct bch_dirent, d_name) -
136 EBUG_ON(bch2_dirent_name_bytes(dirent_i_to_s_c(dirent)) != name->len);
141 int bch2_dirent_create(struct btree_trans *trans,
142 u64 dir_inum, const struct bch_hash_info *hash_info,
143 u8 type, const struct qstr *name, u64 dst_inum,
146 struct bkey_i_dirent *dirent;
149 dirent = dirent_create_key(trans, type, name, dst_inum);
150 ret = PTR_ERR_OR_ZERO(dirent);
154 return bch2_hash_set(trans, bch2_dirent_hash_desc, hash_info,
155 dir_inum, &dirent->k_i, flags);
158 static void dirent_copy_target(struct bkey_i_dirent *dst,
159 struct bkey_s_c_dirent src)
161 dst->v.d_inum = src.v->d_inum;
162 dst->v.d_type = src.v->d_type;
165 int bch2_dirent_rename(struct btree_trans *trans,
166 u64 src_dir, struct bch_hash_info *src_hash,
167 u64 dst_dir, struct bch_hash_info *dst_hash,
168 const struct qstr *src_name, u64 *src_inum,
169 const struct qstr *dst_name, u64 *dst_inum,
170 enum bch_rename_mode mode)
172 struct btree_iter *src_iter = NULL, *dst_iter = NULL;
173 struct bkey_s_c old_src, old_dst;
174 struct bkey_i_dirent *new_src = NULL, *new_dst = NULL;
175 struct bpos dst_pos =
176 POS(dst_dir, bch2_dirent_hash(dst_hash, dst_name));
179 *src_inum = *dst_inum = 0;
184 * Note that in BCH_RENAME mode, we're _not_ checking if
185 * the target already exists - we're relying on the VFS
186 * to do that check for us for correctness:
188 dst_iter = mode == BCH_RENAME
189 ? bch2_hash_hole(trans, bch2_dirent_hash_desc,
190 dst_hash, dst_dir, dst_name)
191 : bch2_hash_lookup(trans, bch2_dirent_hash_desc,
192 dst_hash, dst_dir, dst_name,
194 ret = PTR_ERR_OR_ZERO(dst_iter);
198 old_dst = bch2_btree_iter_peek_slot(dst_iter);
200 if (mode != BCH_RENAME)
201 *dst_inum = le64_to_cpu(bkey_s_c_to_dirent(old_dst).v->d_inum);
204 src_iter = bch2_hash_lookup(trans, bch2_dirent_hash_desc,
205 src_hash, src_dir, src_name,
207 ret = PTR_ERR_OR_ZERO(src_iter);
211 old_src = bch2_btree_iter_peek_slot(src_iter);
212 *src_inum = le64_to_cpu(bkey_s_c_to_dirent(old_src).v->d_inum);
214 /* Create new dst key: */
215 new_dst = dirent_create_key(trans, 0, dst_name, 0);
216 ret = PTR_ERR_OR_ZERO(new_dst);
220 dirent_copy_target(new_dst, bkey_s_c_to_dirent(old_src));
221 new_dst->k.p = dst_iter->pos;
223 /* Create new src key: */
224 if (mode == BCH_RENAME_EXCHANGE) {
225 new_src = dirent_create_key(trans, 0, src_name, 0);
226 ret = PTR_ERR_OR_ZERO(new_src);
230 dirent_copy_target(new_src, bkey_s_c_to_dirent(old_dst));
231 new_src->k.p = src_iter->pos;
233 new_src = bch2_trans_kmalloc(trans, sizeof(struct bkey_i));
234 ret = PTR_ERR_OR_ZERO(new_src);
238 bkey_init(&new_src->k);
239 new_src->k.p = src_iter->pos;
241 if (bkey_cmp(dst_pos, src_iter->pos) <= 0 &&
242 bkey_cmp(src_iter->pos, dst_iter->pos) < 0) {
244 * We have a hash collision for the new dst key,
245 * and new_src - the key we're deleting - is between
246 * new_dst's hashed slot and the slot we're going to be
247 * inserting it into - oops. This will break the hash
248 * table if we don't deal with it:
250 if (mode == BCH_RENAME) {
252 * If we're not overwriting, we can just insert
253 * new_dst at the src position:
255 new_dst->k.p = src_iter->pos;
256 bch2_trans_update(trans, src_iter,
260 /* If we're overwriting, we can't insert new_dst
261 * at a different slot because it has to
262 * overwrite old_dst - just make sure to use a
263 * whiteout when deleting src:
265 new_src->k.type = KEY_TYPE_whiteout;
268 /* Check if we need a whiteout to delete src: */
269 ret = bch2_hash_needs_whiteout(trans, bch2_dirent_hash_desc,
275 new_src->k.type = KEY_TYPE_whiteout;
279 bch2_trans_update(trans, src_iter, &new_src->k_i, 0);
280 bch2_trans_update(trans, dst_iter, &new_dst->k_i, 0);
282 bch2_trans_iter_put(trans, src_iter);
283 bch2_trans_iter_put(trans, dst_iter);
287 int bch2_dirent_delete_at(struct btree_trans *trans,
288 const struct bch_hash_info *hash_info,
289 struct btree_iter *iter)
291 return bch2_hash_delete_at(trans, bch2_dirent_hash_desc,
296 __bch2_dirent_lookup_trans(struct btree_trans *trans, u64 dir_inum,
297 const struct bch_hash_info *hash_info,
298 const struct qstr *name, unsigned flags)
300 return bch2_hash_lookup(trans, bch2_dirent_hash_desc,
301 hash_info, dir_inum, name, flags);
304 u64 bch2_dirent_lookup(struct bch_fs *c, u64 dir_inum,
305 const struct bch_hash_info *hash_info,
306 const struct qstr *name)
308 struct btree_trans trans;
309 struct btree_iter *iter;
313 bch2_trans_init(&trans, c, 0, 0);
315 iter = __bch2_dirent_lookup_trans(&trans, dir_inum,
318 BUG_ON(PTR_ERR(iter) == -EINTR);
322 k = bch2_btree_iter_peek_slot(iter);
323 inum = le64_to_cpu(bkey_s_c_to_dirent(k).v->d_inum);
325 bch2_trans_exit(&trans);
329 int bch2_empty_dir_trans(struct btree_trans *trans, u64 dir_inum)
331 struct btree_iter *iter;
335 for_each_btree_key(trans, iter, BTREE_ID_DIRENTS,
336 POS(dir_inum, 0), 0, k, ret) {
337 if (k.k->p.inode > dir_inum)
340 if (k.k->type == KEY_TYPE_dirent) {
345 bch2_trans_iter_put(trans, iter);
350 int bch2_readdir(struct bch_fs *c, u64 inum, struct dir_context *ctx)
352 struct btree_trans trans;
353 struct btree_iter *iter;
355 struct bkey_s_c_dirent dirent;
358 bch2_trans_init(&trans, c, 0, 0);
360 for_each_btree_key(&trans, iter, BTREE_ID_DIRENTS,
361 POS(inum, ctx->pos), 0, k, ret) {
362 if (k.k->p.inode > inum)
365 if (k.k->type != KEY_TYPE_dirent)
368 dirent = bkey_s_c_to_dirent(k);
371 * XXX: dir_emit() can fault and block, while we're holding
374 ctx->pos = dirent.k->p.offset;
375 if (!dir_emit(ctx, dirent.v->d_name,
376 bch2_dirent_name_bytes(dirent),
377 le64_to_cpu(dirent.v->d_inum),
380 ctx->pos = dirent.k->p.offset + 1;
382 ret = bch2_trans_exit(&trans) ?: ret;