]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - libbcachefs/dirent.c
Update bcachefs sources to 1a739db0b256 bcachefs; guard against overflow in btree...
[bcachefs-tools-debian] / libbcachefs / dirent.c
index 4dfcc955675ba1adbdebabeabbb0b983348eebae..51fe04f45690af5011a87a7777e03140ca762d09 100644 (file)
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 
 #include "bcachefs.h"
+#include "bkey_buf.h"
 #include "bkey_methods.h"
 #include "btree_update.h"
 #include "extents.h"
 
 #include <linux/dcache.h>
 
-unsigned bch2_dirent_name_bytes(struct bkey_s_c_dirent d)
+static unsigned bch2_dirent_name_bytes(struct bkey_s_c_dirent d)
 {
-       unsigned len = bkey_val_bytes(d.k) -
-               offsetof(struct bch_dirent, d_name);
+       unsigned bkey_u64s = bkey_val_u64s(d.k);
+       unsigned bkey_bytes = bkey_u64s * sizeof(u64);
+       u64 last_u64 = ((u64*)d.v)[bkey_u64s - 1];
+#if CPU_BIG_ENDIAN
+       unsigned trailing_nuls = last_u64 ? __builtin_ctzll(last_u64) / 8 : 64 / 8;
+#else
+       unsigned trailing_nuls = last_u64 ? __builtin_clzll(last_u64) / 8 : 64 / 8;
+#endif
+
+       return bkey_bytes -
+               offsetof(struct bch_dirent, d_name) -
+               trailing_nuls;
+}
 
-       return strnlen(d.v->d_name, len);
+struct qstr bch2_dirent_get_name(struct bkey_s_c_dirent d)
+{
+       return (struct qstr) QSTR_INIT(d.v->d_name, bch2_dirent_name_bytes(d));
 }
 
 static u64 bch2_dirent_hash(const struct bch_hash_info *info,
@@ -40,7 +54,7 @@ static u64 dirent_hash_key(const struct bch_hash_info *info, const void *key)
 static u64 dirent_hash_bkey(const struct bch_hash_info *info, struct bkey_s_c k)
 {
        struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
-       struct qstr name = QSTR_INIT(d.v->d_name, bch2_dirent_name_bytes(d));
+       struct qstr name = bch2_dirent_get_name(d);
 
        return bch2_dirent_hash(info, &name);
 }
@@ -48,20 +62,20 @@ static u64 dirent_hash_bkey(const struct bch_hash_info *info, struct bkey_s_c k)
 static bool dirent_cmp_key(struct bkey_s_c _l, const void *_r)
 {
        struct bkey_s_c_dirent l = bkey_s_c_to_dirent(_l);
-       int len = bch2_dirent_name_bytes(l);
-       const struct qstr *r = _r;
+       const struct qstr l_name = bch2_dirent_get_name(l);
+       const struct qstr *r_name = _r;
 
-       return len - r->len ?: memcmp(l.v->d_name, r->name, len);
+       return !qstr_eq(l_name, *r_name);
 }
 
 static bool dirent_cmp_bkey(struct bkey_s_c _l, struct bkey_s_c _r)
 {
        struct bkey_s_c_dirent l = bkey_s_c_to_dirent(_l);
        struct bkey_s_c_dirent r = bkey_s_c_to_dirent(_r);
-       int l_len = bch2_dirent_name_bytes(l);
-       int r_len = bch2_dirent_name_bytes(r);
+       const struct qstr l_name = bch2_dirent_get_name(l);
+       const struct qstr r_name = bch2_dirent_get_name(r);
 
-       return l_len - r_len ?: memcmp(l.v->d_name, r.v->d_name, l_len);
+       return !qstr_eq(l_name, r_name);
 }
 
 static bool dirent_is_visible(subvol_inum inum, struct bkey_s_c k)
@@ -83,48 +97,62 @@ const struct bch_hash_desc bch2_dirent_hash_desc = {
        .is_visible     = dirent_is_visible,
 };
 
-const char *bch2_dirent_invalid(const struct bch_fs *c, struct bkey_s_c k)
+int bch2_dirent_invalid(struct bch_fs *c, struct bkey_s_c k,
+                       enum bkey_invalid_flags flags,
+                       struct printbuf *err)
 {
        struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
-       unsigned len;
-
-       if (bkey_val_bytes(k.k) < sizeof(struct bch_dirent))
-               return "value too small";
-
-       len = bch2_dirent_name_bytes(d);
-       if (!len)
-               return "empty name";
-
-       if (bkey_val_u64s(k.k) > dirent_val_u64s(len))
-               return "value too big";
-
-       if (len > BCH_NAME_MAX)
-               return "dirent name too big";
-
-       if (len == 1 && !memcmp(d.v->d_name, ".", 1))
-               return "invalid name";
-
-       if (len == 2 && !memcmp(d.v->d_name, "..", 2))
-               return "invalid name";
+       struct qstr d_name = bch2_dirent_get_name(d);
+       int ret = 0;
 
-       if (memchr(d.v->d_name, '/', len))
-               return "invalid name";
+       bkey_fsck_err_on(!d_name.len, c, err,
+                        dirent_empty_name,
+                        "empty name");
 
-       if (d.v->d_type != DT_SUBVOL &&
-           le64_to_cpu(d.v->d_inum) == d.k->p.inode)
-               return "dirent points to own directory";
+       bkey_fsck_err_on(bkey_val_u64s(k.k) > dirent_val_u64s(d_name.len), c, err,
+                        dirent_val_too_big,
+                        "value too big (%zu > %u)",
+                        bkey_val_u64s(k.k), dirent_val_u64s(d_name.len));
 
-       return NULL;
+       /*
+        * Check new keys don't exceed the max length
+        * (older keys may be larger.)
+        */
+       bkey_fsck_err_on((flags & BKEY_INVALID_COMMIT) && d_name.len > BCH_NAME_MAX, c, err,
+                        dirent_name_too_long,
+                        "dirent name too big (%u > %u)",
+                        d_name.len, BCH_NAME_MAX);
+
+       bkey_fsck_err_on(d_name.len != strnlen(d_name.name, d_name.len), c, err,
+                        dirent_name_embedded_nul,
+                        "dirent has stray data after name's NUL");
+
+       bkey_fsck_err_on((d_name.len == 1 && !memcmp(d_name.name, ".", 1)) ||
+                        (d_name.len == 2 && !memcmp(d_name.name, "..", 2)), c, err,
+                        dirent_name_dot_or_dotdot,
+                        "invalid name");
+
+       bkey_fsck_err_on(memchr(d_name.name, '/', d_name.len), c, err,
+                        dirent_name_has_slash,
+                        "name with /");
+
+       bkey_fsck_err_on(d.v->d_type != DT_SUBVOL &&
+                        le64_to_cpu(d.v->d_inum) == d.k->p.inode, c, err,
+                        dirent_to_itself,
+                        "dirent points to own directory");
+fsck_err:
+       return ret;
 }
 
 void bch2_dirent_to_text(struct printbuf *out, struct bch_fs *c,
                         struct bkey_s_c k)
 {
        struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
+       struct qstr d_name = bch2_dirent_get_name(d);
 
-       bch_scnmemcpy(out, d.v->d_name,
-                     bch2_dirent_name_bytes(d));
-       pr_buf(out, " -> %llu type %s",
+       prt_printf(out, "%.*s -> %llu type %s",
+              d_name.len,
+              d_name.name,
               d.v->d_type != DT_SUBVOL
               ? le64_to_cpu(d.v->d_inum)
               : le32_to_cpu(d.v->d_child_subvol),
@@ -173,7 +201,8 @@ static struct bkey_i_dirent *dirent_create_key(struct btree_trans *trans,
 int bch2_dirent_create(struct btree_trans *trans, subvol_inum dir,
                       const struct bch_hash_info *hash_info,
                       u8 type, const struct qstr *name, u64 dst_inum,
-                      u64 *dir_offset, int flags)
+                      u64 *dir_offset,
+                      bch_str_hash_flags_t str_hash_flags)
 {
        struct bkey_i_dirent *dirent;
        int ret;
@@ -184,7 +213,7 @@ int bch2_dirent_create(struct btree_trans *trans, subvol_inum dir,
                return ret;
 
        ret = bch2_hash_set(trans, bch2_dirent_hash_desc, hash_info,
-                           dir, &dirent->k_i, flags);
+                           dir, &dirent->k_i, str_hash_flags);
        *dir_offset = dirent->k.p.offset;
 
        return ret;
@@ -204,7 +233,7 @@ int bch2_dirent_read_target(struct btree_trans *trans, subvol_inum dir,
        int ret = 0;
 
        if (d.v->d_type == DT_SUBVOL &&
-           d.v->d_parent_subvol != dir.subvol)
+           le32_to_cpu(d.v->d_parent_subvol) != dir.subvol)
                return 1;
 
        if (likely(d.v->d_type != DT_SUBVOL)) {
@@ -230,7 +259,7 @@ int bch2_dirent_rename(struct btree_trans *trans,
 {
        struct btree_iter src_iter = { NULL };
        struct btree_iter dst_iter = { NULL };
-       struct bkey_s_c old_src, old_dst;
+       struct bkey_s_c old_src, old_dst = bkey_s_c_null;
        struct bkey_i_dirent *new_src = NULL, *new_dst = NULL;
        struct bpos dst_pos =
                POS(dst_dir.inum, bch2_dirent_hash(dst_hash, dst_name));
@@ -330,8 +359,8 @@ int bch2_dirent_rename(struct btree_trans *trans,
                bkey_init(&new_src->k);
                new_src->k.p = src_iter.pos;
 
-               if (bkey_cmp(dst_pos, src_iter.pos) <= 0 &&
-                   bkey_cmp(src_iter.pos, dst_iter.pos) < 0) {
+               if (bkey_le(dst_pos, src_iter.pos) &&
+                   bkey_lt(src_iter.pos, dst_iter.pos)) {
                        /*
                         * We have a hash collision for the new dst key,
                         * and new_src - the key we're deleting - is between
@@ -367,7 +396,9 @@ int bch2_dirent_rename(struct btree_trans *trans,
                }
        }
 
-       bch2_trans_update(trans, &dst_iter, &new_dst->k_i, 0);
+       ret = bch2_trans_update(trans, &dst_iter, &new_dst->k_i, 0);
+       if (ret)
+               goto out;
 out_set_src:
 
        /*
@@ -384,7 +415,9 @@ out_set_src:
                src_update_flags |= BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE;
        }
 
-       bch2_trans_update(trans, &src_iter, &new_src->k_i, src_update_flags);
+       ret = bch2_trans_update(trans, &src_iter, &new_src->k_i, src_update_flags);
+       if (ret)
+               goto out;
 
        if (mode == BCH_RENAME_EXCHANGE)
                *src_offset = new_src->k.p.offset;
@@ -437,91 +470,86 @@ u64 bch2_dirent_lookup(struct bch_fs *c, subvol_inum dir,
                       const struct bch_hash_info *hash_info,
                       const struct qstr *name, subvol_inum *inum)
 {
-       struct btree_trans trans;
-       struct btree_iter iter;
-       int ret;
+       struct btree_trans *trans = bch2_trans_get(c);
+       struct btree_iter iter = { NULL };
 
-       bch2_trans_init(&trans, c, 0, 0);
-retry:
-       bch2_trans_begin(&trans);
-
-       ret = __bch2_dirent_lookup_trans(&trans, &iter, dir, hash_info,
-                                         name, inum, 0);
-       if (ret == -EINTR)
-               goto retry;
-       if (!ret)
-               bch2_trans_iter_exit(&trans, &iter);
-       bch2_trans_exit(&trans);
+       int ret = lockrestart_do(trans,
+               __bch2_dirent_lookup_trans(trans, &iter, dir, hash_info, name, inum, 0));
+       bch2_trans_iter_exit(trans, &iter);
+       bch2_trans_put(trans);
        return ret;
 }
 
-int bch2_empty_dir_trans(struct btree_trans *trans, subvol_inum dir)
+int bch2_empty_dir_snapshot(struct btree_trans *trans, u64 dir, u32 snapshot)
 {
        struct btree_iter iter;
        struct bkey_s_c k;
-       u32 snapshot;
        int ret;
 
-       ret = bch2_subvolume_get_snapshot(trans, dir.subvol, &snapshot);
-       if (ret)
-               return ret;
-
-       for_each_btree_key_norestart(trans, iter, BTREE_ID_dirents,
-                          SPOS(dir.inum, 0, snapshot), 0, k, ret) {
-               if (k.k->p.inode > dir.inum)
-                       break;
-
+       for_each_btree_key_upto_norestart(trans, iter, BTREE_ID_dirents,
+                          SPOS(dir, 0, snapshot),
+                          POS(dir, U64_MAX), 0, k, ret)
                if (k.k->type == KEY_TYPE_dirent) {
                        ret = -ENOTEMPTY;
                        break;
                }
-       }
        bch2_trans_iter_exit(trans, &iter);
 
        return ret;
 }
 
+int bch2_empty_dir_trans(struct btree_trans *trans, subvol_inum dir)
+{
+       u32 snapshot;
+
+       return bch2_subvolume_get_snapshot(trans, dir.subvol, &snapshot) ?:
+               bch2_empty_dir_snapshot(trans, dir.inum, snapshot);
+}
+
 int bch2_readdir(struct bch_fs *c, subvol_inum inum, struct dir_context *ctx)
 {
-       struct btree_trans trans;
+       struct btree_trans *trans = bch2_trans_get(c);
        struct btree_iter iter;
        struct bkey_s_c k;
        struct bkey_s_c_dirent dirent;
        subvol_inum target;
        u32 snapshot;
+       struct bkey_buf sk;
+       struct qstr name;
        int ret;
 
-       bch2_trans_init(&trans, c, 0, 0);
+       bch2_bkey_buf_init(&sk);
 retry:
-       bch2_trans_begin(&trans);
+       bch2_trans_begin(trans);
 
-       ret = bch2_subvolume_get_snapshot(&trans, inum.subvol, &snapshot);
+       ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
        if (ret)
                goto err;
 
-       for_each_btree_key_norestart(&trans, iter, BTREE_ID_dirents,
-                          SPOS(inum.inum, ctx->pos, snapshot), 0, k, ret) {
-               if (k.k->p.inode > inum.inum)
-                       break;
-
+       for_each_btree_key_upto_norestart(trans, iter, BTREE_ID_dirents,
+                          SPOS(inum.inum, ctx->pos, snapshot),
+                          POS(inum.inum, U64_MAX), 0, k, ret) {
                if (k.k->type != KEY_TYPE_dirent)
                        continue;
 
                dirent = bkey_s_c_to_dirent(k);
 
-               ret = bch2_dirent_read_target(&trans, inum, dirent, &target);
+               ret = bch2_dirent_read_target(trans, inum, dirent, &target);
                if (ret < 0)
                        break;
                if (ret)
                        continue;
 
-               /*
-                * XXX: dir_emit() can fault and block, while we're holding
-                * locks
-                */
+               /* dir_emit() can fault and block: */
+               bch2_bkey_buf_reassemble(&sk, c, k);
+               dirent = bkey_i_to_s_c_dirent(sk.k);
+               bch2_trans_unlock(trans);
+
+               name = bch2_dirent_get_name(dirent);
+
                ctx->pos = dirent.k->p.offset;
-               if (!dir_emit(ctx, dirent.v->d_name,
-                             bch2_dirent_name_bytes(dirent),
+               if (!dir_emit(ctx, name.name,
+                             name.len,
                              target.inum,
                              vfs_d_type(dirent.v->d_type)))
                        break;
@@ -531,17 +559,17 @@ retry:
                 * read_target looks up subvolumes, we can overflow paths if the
                 * directory has many subvolumes in it
                 */
-               if (hweight64(trans.paths_allocated) > BTREE_ITER_MAX / 2) {
-                       ret = -EINTR;
+               ret = btree_trans_too_many_iters(trans);
+               if (ret)
                        break;
-               }
        }
-       bch2_trans_iter_exit(&trans, &iter);
+       bch2_trans_iter_exit(trans, &iter);
 err:
-       if (ret == -EINTR)
+       if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
                goto retry;
 
-       bch2_trans_exit(&trans);
+       bch2_trans_put(trans);
+       bch2_bkey_buf_exit(&sk, c);
 
        return ret;
 }