]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - libbcachefs/dirent.c
Update bcachefs sources to a8115093df bcachefs: Fix divide by zero in rebalance_work()
[bcachefs-tools-debian] / libbcachefs / dirent.c
index a43a24409d37d627c8f0214acb87157519717de9..a7559ab03802cb3a39a6dc17d563cb9f3dced5a4 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 l_name.len - r_name->len ?: memcmp(l_name.name, r_name->name, l_name.len);
 }
 
 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 l_name.len - r_name.len ?: memcmp(l_name.name, r_name.name, l_name.len);
 }
 
 static bool dirent_is_visible(subvol_inum inum, struct bkey_s_c k)
@@ -83,48 +97,72 @@ 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(const 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;
+       struct qstr d_name = bch2_dirent_get_name(d);
 
-       if (bkey_val_bytes(k.k) < sizeof(struct bch_dirent))
-               return "value too small";
+       if (!d_name.len) {
+               prt_printf(err, "empty name");
+               return -BCH_ERR_invalid_bkey;
+       }
 
-       len = bch2_dirent_name_bytes(d);
-       if (!len)
-               return "empty name";
+       if (bkey_val_u64s(k.k) > dirent_val_u64s(d_name.len)) {
+               prt_printf(err, "value too big (%zu > %u)",
+                      bkey_val_u64s(k.k), dirent_val_u64s(d_name.len));
+               return -BCH_ERR_invalid_bkey;
+       }
 
-       if (bkey_val_u64s(k.k) > dirent_val_u64s(len))
-               return "value too big";
+       /*
+        * Check new keys don't exceed the max length
+        * (older keys may be larger.)
+        */
+       if ((flags & BKEY_INVALID_COMMIT) && d_name.len > BCH_NAME_MAX) {
+               prt_printf(err, "dirent name too big (%u > %u)",
+                      d_name.len, BCH_NAME_MAX);
+               return -BCH_ERR_invalid_bkey;
+       }
 
-       if (len > BCH_NAME_MAX)
-               return "dirent name too big";
+       if (d_name.len != strnlen(d_name.name, d_name.len)) {
+               prt_printf(err, "dirent has stray data after name's NUL");
+               return -BCH_ERR_invalid_bkey;
+       }
 
-       if (len == 1 && !memcmp(d.v->d_name, ".", 1))
-               return "invalid name";
+       if (d_name.len == 1 && !memcmp(d_name.name, ".", 1)) {
+               prt_printf(err, "invalid name");
+               return -BCH_ERR_invalid_bkey;
+       }
 
-       if (len == 2 && !memcmp(d.v->d_name, "..", 2))
-               return "invalid name";
+       if (d_name.len == 2 && !memcmp(d_name.name, "..", 2)) {
+               prt_printf(err, "invalid name");
+               return -BCH_ERR_invalid_bkey;
+       }
 
-       if (memchr(d.v->d_name, '/', len))
-               return "invalid name";
+       if (memchr(d_name.name, '/', d_name.len)) {
+               prt_printf(err, "invalid name");
+               return -BCH_ERR_invalid_bkey;
+       }
 
        if (d.v->d_type != DT_SUBVOL &&
-           le64_to_cpu(d.v->d_inum) == d.k->p.inode)
-               return "dirent points to own directory";
+           le64_to_cpu(d.v->d_inum) == d.k->p.inode) {
+               prt_printf(err, "dirent points to own directory");
+               return -BCH_ERR_invalid_bkey;
+       }
 
-       return NULL;
+       return 0;
 }
 
 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);
 
-       pr_buf(out, "%.*s -> %llu type %s",
-              bch2_dirent_name_bytes(d),
-              d.v->d_name,
+       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),
@@ -204,7 +242,7 @@ 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)) {
@@ -330,8 +368,8 @@ 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
@@ -451,7 +489,7 @@ retry:
 
        ret = __bch2_dirent_lookup_trans(&trans, &iter, dir, hash_info,
                                          name, inum, 0);
-       if (ret == -EINTR)
+       if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
                goto retry;
        if (!ret)
                bch2_trans_iter_exit(&trans, &iter);
@@ -470,16 +508,13 @@ int bch2_empty_dir_trans(struct btree_trans *trans, subvol_inum dir)
        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.inum, 0, snapshot),
+                          POS(dir.inum, U64_MAX), 0, k, ret)
                if (k.k->type == KEY_TYPE_dirent) {
                        ret = -ENOTEMPTY;
                        break;
                }
-       }
        bch2_trans_iter_exit(trans, &iter);
 
        return ret;
@@ -493,8 +528,11 @@ int bch2_readdir(struct bch_fs *c, subvol_inum inum, struct dir_context *ctx)
        struct bkey_s_c_dirent dirent;
        subvol_inum target;
        u32 snapshot;
+       struct bkey_buf sk;
+       struct qstr name;
        int ret;
 
+       bch2_bkey_buf_init(&sk);
        bch2_trans_init(&trans, c, 0, 0);
 retry:
        bch2_trans_begin(&trans);
@@ -503,11 +541,9 @@ retry:
        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;
 
@@ -519,13 +555,16 @@ retry:
                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;
@@ -541,10 +580,11 @@ retry:
        }
        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_bkey_buf_exit(&sk, c);
 
        return ret;
 }