]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - libbcachefs/dirent.c
Update bcachefs sources to 96b991466a bcachefs: Improve error message in fsck
[bcachefs-tools-debian] / libbcachefs / dirent.c
index 36dca6b22a9144fac247ccd1a22bdac7734c5c1a..ae5c9fd8d9f7bacc9dae437b3e53b916822bf4db 100644 (file)
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 
 #include "bcachefs.h"
 #include "bkey_methods.h"
@@ -15,16 +16,7 @@ unsigned bch2_dirent_name_bytes(struct bkey_s_c_dirent d)
        unsigned len = bkey_val_bytes(d.k) -
                offsetof(struct bch_dirent, d_name);
 
-       while (len && !d.v->d_name[len - 1])
-               --len;
-
-       return len;
-}
-
-static unsigned dirent_val_u64s(unsigned len)
-{
-       return DIV_ROUND_UP(offsetof(struct bch_dirent, d_name) + len,
-                           sizeof(u64));
+       return strnlen(d.v->d_name, len);
 }
 
 static u64 bch2_dirent_hash(const struct bch_hash_info *info,
@@ -73,8 +65,7 @@ static bool dirent_cmp_bkey(struct bkey_s_c _l, struct bkey_s_c _r)
 
 const struct bch_hash_desc bch2_dirent_hash_desc = {
        .btree_id       = BTREE_ID_DIRENTS,
-       .key_type       = BCH_DIRENT,
-       .whiteout_type  = BCH_DIRENT_WHITEOUT,
+       .key_type       = KEY_TYPE_dirent,
        .hash_key       = dirent_hash_key,
        .hash_bkey      = dirent_hash_bkey,
        .cmp_key        = dirent_cmp_key,
@@ -83,62 +74,41 @@ const struct bch_hash_desc bch2_dirent_hash_desc = {
 
 const char *bch2_dirent_invalid(const struct bch_fs *c, struct bkey_s_c k)
 {
-       struct bkey_s_c_dirent d;
+       struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
        unsigned len;
 
-       switch (k.k->type) {
-       case BCH_DIRENT:
-               if (bkey_val_bytes(k.k) < sizeof(struct bch_dirent))
-                       return "value too small";
-
-               d = bkey_s_c_to_dirent(k);
-               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 (bkey_val_bytes(k.k) < sizeof(struct bch_dirent))
+               return "value too small";
 
-               if (len > BCH_NAME_MAX)
-                       return "dirent name too big";
+       len = bch2_dirent_name_bytes(d);
+       if (!len)
+               return "empty name";
 
-               if (memchr(d.v->d_name, '/', len))
-                       return "dirent name has invalid characters";
+       /*
+        * older versions of bcachefs were buggy and creating dirent
+        * keys that were bigger than necessary:
+        */
+       if (bkey_val_u64s(k.k) > dirent_val_u64s(len + 7))
+               return "value too big";
 
-               return NULL;
-       case BCH_DIRENT_WHITEOUT:
-               return bkey_val_bytes(k.k) != 0
-                       ? "value size should be zero"
-                       : NULL;
+       if (len > BCH_NAME_MAX)
+               return "dirent name too big";
 
-       default:
-               return "invalid type";
-       }
+       return NULL;
 }
 
-void bch2_dirent_to_text(struct bch_fs *c, char *buf,
-                        size_t size, struct bkey_s_c k)
+void bch2_dirent_to_text(struct printbuf *out, struct bch_fs *c,
+                        struct bkey_s_c k)
 {
-       struct bkey_s_c_dirent d;
-       size_t n = 0;
-
-       switch (k.k->type) {
-       case BCH_DIRENT:
-               d = bkey_s_c_to_dirent(k);
-
-               n += bch_scnmemcpy(buf + n, size - n, d.v->d_name,
-                                  bch2_dirent_name_bytes(d));
-               n += scnprintf(buf + n, size - n, " -> %llu", d.v->d_inum);
-               break;
-       case BCH_DIRENT_WHITEOUT:
-               scnprintf(buf, size, "whiteout");
-               break;
-       }
+       struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
+
+       bch_scnmemcpy(out, d.v->d_name,
+                     bch2_dirent_name_bytes(d));
+       pr_buf(out, " -> %llu", d.v->d_inum);
 }
 
-static struct bkey_i_dirent *dirent_create_key(u8 type,
-                               const struct qstr *name, u64 dst)
+static struct bkey_i_dirent *dirent_create_key(struct btree_trans *trans,
+                               u8 type, const struct qstr *name, u64 dst)
 {
        struct bkey_i_dirent *dirent;
        unsigned u64s = BKEY_U64s + dirent_val_u64s(name->len);
@@ -148,9 +118,9 @@ static struct bkey_i_dirent *dirent_create_key(u8 type,
 
        BUG_ON(u64s > U8_MAX);
 
-       dirent = kmalloc(u64s * sizeof(u64), GFP_NOFS);
-       if (!dirent)
-               return ERR_PTR(-ENOMEM);
+       dirent = bch2_trans_kmalloc(trans, u64s * sizeof(u64));
+       if (IS_ERR(dirent))
+               return dirent;
 
        bkey_dirent_init(&dirent->k_i);
        dirent->k.u64s = u64s;
@@ -168,23 +138,21 @@ static struct bkey_i_dirent *dirent_create_key(u8 type,
        return dirent;
 }
 
-int bch2_dirent_create(struct bch_fs *c, u64 dir_inum,
-                      const struct bch_hash_info *hash_info,
+int bch2_dirent_create(struct btree_trans *trans,
+                      u64 dir_inum, const struct bch_hash_info *hash_info,
                       u8 type, const struct qstr *name, u64 dst_inum,
-                      u64 *journal_seq, int flags)
+                      int flags)
 {
        struct bkey_i_dirent *dirent;
        int ret;
 
-       dirent = dirent_create_key(type, name, dst_inum);
-       if (IS_ERR(dirent))
-               return PTR_ERR(dirent);
-
-       ret = bch2_hash_set(bch2_dirent_hash_desc, hash_info, c, dir_inum,
-                          journal_seq, &dirent->k_i, flags);
-       kfree(dirent);
+       dirent = dirent_create_key(trans, type, name, dst_inum);
+       ret = PTR_ERR_OR_ZERO(dirent);
+       if (ret)
+               return ret;
 
-       return ret;
+       return bch2_hash_set(trans, bch2_dirent_hash_desc, hash_info,
+                            dir_inum, &dirent->k_i, flags);
 }
 
 static void dirent_copy_target(struct bkey_i_dirent *dst,
@@ -194,248 +162,224 @@ static void dirent_copy_target(struct bkey_i_dirent *dst,
        dst->v.d_type = src.v->d_type;
 }
 
-static struct bpos bch2_dirent_pos(struct bch_inode_info *inode,
-                                  const struct qstr *name)
-{
-       return POS(inode->v.i_ino, bch2_dirent_hash(&inode->ei_str_hash, name));
-}
-
-int bch2_dirent_rename(struct bch_fs *c,
-               struct bch_inode_info *src_dir, const struct qstr *src_name,
-               struct bch_inode_info *dst_dir, const struct qstr *dst_name,
-               u64 *journal_seq, enum bch_rename_mode mode)
+int bch2_dirent_rename(struct btree_trans *trans,
+                      u64 src_dir, struct bch_hash_info *src_hash,
+                      u64 dst_dir, struct bch_hash_info *dst_hash,
+                      const struct qstr *src_name, u64 *src_inum,
+                      const struct qstr *dst_name, u64 *dst_inum,
+                      enum bch_rename_mode mode)
 {
-       struct btree_iter src_iter, dst_iter, whiteout_iter;
+       struct btree_iter *src_iter = NULL, *dst_iter = NULL;
        struct bkey_s_c old_src, old_dst;
-       struct bkey delete;
        struct bkey_i_dirent *new_src = NULL, *new_dst = NULL;
-       struct bpos src_pos = bch2_dirent_pos(src_dir, src_name);
-       struct bpos dst_pos = bch2_dirent_pos(dst_dir, dst_name);
-       bool need_whiteout;
-       int ret;
-
-       bch2_btree_iter_init(&src_iter, c, BTREE_ID_DIRENTS, src_pos,
-                            BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
-       bch2_btree_iter_init(&dst_iter, c, BTREE_ID_DIRENTS, dst_pos,
-                            BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
-       bch2_btree_iter_link(&src_iter, &dst_iter);
-
-       bch2_btree_iter_init(&whiteout_iter, c, BTREE_ID_DIRENTS, src_pos,
-                            BTREE_ITER_SLOTS);
-       bch2_btree_iter_link(&src_iter, &whiteout_iter);
-
-       if (mode == BCH_RENAME_EXCHANGE) {
-               new_src = dirent_create_key(0, src_name, 0);
-               if (IS_ERR(new_src)) {
-                       ret = PTR_ERR(new_src);
-                       goto err;
-               }
-       } else {
-               new_src = (void *) &delete;
-       }
+       struct bpos dst_pos =
+               POS(dst_dir, bch2_dirent_hash(dst_hash, dst_name));
+       int ret = 0;
 
-       new_dst = dirent_create_key(0, dst_name, 0);
-       if (IS_ERR(new_dst)) {
-               ret = PTR_ERR(new_dst);
-               goto err;
-       }
-retry:
-       /*
-        * Note that on -EINTR/dropped locks we're not restarting the lookup
-        * from the original hashed position (like we do when creating dirents,
-        * in bch_hash_set) -  we never move existing dirents to different slot:
-        */
-       old_src = bch2_hash_lookup_at(bch2_dirent_hash_desc,
-                                    &src_dir->ei_str_hash,
-                                    &src_iter, src_name);
-       if ((ret = btree_iter_err(old_src)))
-               goto err;
-
-       ret = bch2_hash_needs_whiteout(bch2_dirent_hash_desc,
-                               &src_dir->ei_str_hash,
-                               &whiteout_iter, &src_iter);
-       if (ret < 0)
-               goto err;
-       need_whiteout = ret;
+       *src_inum = *dst_inum = 0;
 
        /*
+        * Lookup dst:
+        *
         * Note that in BCH_RENAME mode, we're _not_ checking if
         * the target already exists - we're relying on the VFS
         * to do that check for us for correctness:
         */
-       old_dst = mode == BCH_RENAME
-               ? bch2_hash_hole_at(bch2_dirent_hash_desc, &dst_iter)
-               : bch2_hash_lookup_at(bch2_dirent_hash_desc,
-                                    &dst_dir->ei_str_hash,
-                                    &dst_iter, dst_name);
-       if ((ret = btree_iter_err(old_dst)))
-               goto err;
-
-       switch (mode) {
-       case BCH_RENAME:
-               bkey_init(&new_src->k);
-               dirent_copy_target(new_dst, bkey_s_c_to_dirent(old_src));
+       dst_iter = mode == BCH_RENAME
+               ? bch2_hash_hole(trans, bch2_dirent_hash_desc,
+                                dst_hash, dst_dir, dst_name)
+               : bch2_hash_lookup(trans, bch2_dirent_hash_desc,
+                                  dst_hash, dst_dir, dst_name,
+                                  BTREE_ITER_INTENT);
+       ret = PTR_ERR_OR_ZERO(dst_iter);
+       if (ret)
+               goto out;
+
+       old_dst = bch2_btree_iter_peek_slot(dst_iter);
+
+       if (mode != BCH_RENAME)
+               *dst_inum = le64_to_cpu(bkey_s_c_to_dirent(old_dst).v->d_inum);
+
+       /* Lookup src: */
+       src_iter = bch2_hash_lookup(trans, bch2_dirent_hash_desc,
+                                   src_hash, src_dir, src_name,
+                                   BTREE_ITER_INTENT);
+       ret = PTR_ERR_OR_ZERO(src_iter);
+       if (ret)
+               goto out;
+
+       old_src = bch2_btree_iter_peek_slot(src_iter);
+       *src_inum = le64_to_cpu(bkey_s_c_to_dirent(old_src).v->d_inum);
+
+       /* Create new dst key: */
+       new_dst = dirent_create_key(trans, 0, dst_name, 0);
+       ret = PTR_ERR_OR_ZERO(new_dst);
+       if (ret)
+               goto out;
+
+       dirent_copy_target(new_dst, bkey_s_c_to_dirent(old_src));
+       new_dst->k.p = dst_iter->pos;
+
+       /* Create new src key: */
+       if (mode == BCH_RENAME_EXCHANGE) {
+               new_src = dirent_create_key(trans, 0, src_name, 0);
+               ret = PTR_ERR_OR_ZERO(new_src);
+               if (ret)
+                       goto out;
 
-               if (bkey_cmp(dst_pos, src_iter.pos) <= 0 &&
-                   bkey_cmp(src_iter.pos, dst_iter.pos) < 0) {
-                       /*
-                        * If we couldn't insert new_dst at its hashed
-                        * position (dst_pos) due to a hash collision,
-                        * and we're going to be deleting in
-                        * between the hashed position and first empty
-                        * slot we found - just overwrite the pos we
-                        * were going to delete:
-                        *
-                        * Note: this is a correctness issue, in this
-                        * situation bch2_hash_needs_whiteout() could
-                        * return false when the whiteout would have
-                        * been needed if we inserted at the pos
-                        * __dirent_find_hole() found
-                        */
-                       new_dst->k.p = src_iter.pos;
-                       ret = bch2_btree_insert_at(c, NULL, NULL,
-                                       journal_seq,
-                                       BTREE_INSERT_ATOMIC,
-                                       BTREE_INSERT_ENTRY(&src_iter,
-                                                          &new_dst->k_i));
-                       goto err;
-               }
+               dirent_copy_target(new_src, bkey_s_c_to_dirent(old_dst));
+               new_src->k.p = src_iter->pos;
+       } else {
+               new_src = bch2_trans_kmalloc(trans, sizeof(struct bkey_i));
+               ret = PTR_ERR_OR_ZERO(new_src);
+               if (ret)
+                       goto out;
 
-               if (need_whiteout)
-                       new_src->k.type = BCH_DIRENT_WHITEOUT;
-               break;
-       case BCH_RENAME_OVERWRITE:
                bkey_init(&new_src->k);
-               dirent_copy_target(new_dst, bkey_s_c_to_dirent(old_src));
+               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_cmp(dst_pos, src_iter->pos) <= 0 &&
+                   bkey_cmp(src_iter->pos, dst_iter->pos) < 0) {
                        /*
-                        * Same case described above -
-                        * bch_hash_needs_whiteout could spuriously
-                        * return false, but we have to insert at
-                        * dst_iter.pos because we're overwriting
-                        * another dirent:
+                        * We have a hash collision for the new dst key,
+                        * and new_src - the key we're deleting - is between
+                        * new_dst's hashed slot and the slot we're going to be
+                        * inserting it into - oops.  This will break the hash
+                        * table if we don't deal with it:
                         */
-                       new_src->k.type = BCH_DIRENT_WHITEOUT;
-               } else if (need_whiteout)
-                       new_src->k.type = BCH_DIRENT_WHITEOUT;
-               break;
-       case BCH_RENAME_EXCHANGE:
-               dirent_copy_target(new_src, bkey_s_c_to_dirent(old_dst));
-               dirent_copy_target(new_dst, bkey_s_c_to_dirent(old_src));
-               break;
+                       if (mode == BCH_RENAME) {
+                               /*
+                                * If we're not overwriting, we can just insert
+                                * new_dst at the src position:
+                                */
+                               new_dst->k.p = src_iter->pos;
+                               bch2_trans_update(trans, src_iter,
+                                                 &new_dst->k_i, 0);
+                               goto out;
+                       } else {
+                               /* If we're overwriting, we can't insert new_dst
+                                * at a different slot because it has to
+                                * overwrite old_dst - just make sure to use a
+                                * whiteout when deleting src:
+                                */
+                               new_src->k.type = KEY_TYPE_whiteout;
+                       }
+               } else {
+                       /* Check if we need a whiteout to delete src: */
+                       ret = bch2_hash_needs_whiteout(trans, bch2_dirent_hash_desc,
+                                                      src_hash, src_iter);
+                       if (ret < 0)
+                               goto out;
+
+                       if (ret)
+                               new_src->k.type = KEY_TYPE_whiteout;
+               }
        }
 
-       new_src->k.p = src_iter.pos;
-       new_dst->k.p = dst_iter.pos;
-       ret = bch2_btree_insert_at(c, NULL, NULL, journal_seq,
-                       BTREE_INSERT_ATOMIC,
-                       BTREE_INSERT_ENTRY(&src_iter, &new_src->k_i),
-                       BTREE_INSERT_ENTRY(&dst_iter, &new_dst->k_i));
-err:
-       if (ret == -EINTR)
-               goto retry;
-
-       bch2_btree_iter_unlock(&whiteout_iter);
-       bch2_btree_iter_unlock(&dst_iter);
-       bch2_btree_iter_unlock(&src_iter);
-
-       if (new_src != (void *) &delete)
-               kfree(new_src);
-       kfree(new_dst);
+       bch2_trans_update(trans, src_iter, &new_src->k_i, 0);
+       bch2_trans_update(trans, dst_iter, &new_dst->k_i, 0);
+out:
+       bch2_trans_iter_put(trans, src_iter);
+       bch2_trans_iter_put(trans, dst_iter);
        return ret;
 }
 
-int bch2_dirent_delete(struct bch_fs *c, u64 dir_inum,
-                      const struct bch_hash_info *hash_info,
-                      const struct qstr *name,
-                      u64 *journal_seq)
+int bch2_dirent_delete_at(struct btree_trans *trans,
+                         const struct bch_hash_info *hash_info,
+                         struct btree_iter *iter)
+{
+       return bch2_hash_delete_at(trans, bch2_dirent_hash_desc,
+                                  hash_info, iter);
+}
+
+struct btree_iter *
+__bch2_dirent_lookup_trans(struct btree_trans *trans, u64 dir_inum,
+                          const struct bch_hash_info *hash_info,
+                          const struct qstr *name, unsigned flags)
 {
-       return bch2_hash_delete(bch2_dirent_hash_desc, hash_info,
-                              c, dir_inum, journal_seq, name);
+       return bch2_hash_lookup(trans, bch2_dirent_hash_desc,
+                               hash_info, dir_inum, name, flags);
 }
 
 u64 bch2_dirent_lookup(struct bch_fs *c, u64 dir_inum,
                       const struct bch_hash_info *hash_info,
                       const struct qstr *name)
 {
-       struct btree_iter iter;
+       struct btree_trans trans;
+       struct btree_iter *iter;
        struct bkey_s_c k;
-       u64 inum;
+       u64 inum = 0;
 
-       k = bch2_hash_lookup(bch2_dirent_hash_desc, hash_info, c,
-                           dir_inum, &iter, name);
-       if (IS_ERR(k.k)) {
-               bch2_btree_iter_unlock(&iter);
-               return 0;
+       bch2_trans_init(&trans, c, 0, 0);
+
+       iter = __bch2_dirent_lookup_trans(&trans, dir_inum,
+                                         hash_info, name, 0);
+       if (IS_ERR(iter)) {
+               BUG_ON(PTR_ERR(iter) == -EINTR);
+               goto out;
        }
 
+       k = bch2_btree_iter_peek_slot(iter);
        inum = le64_to_cpu(bkey_s_c_to_dirent(k).v->d_inum);
-       bch2_btree_iter_unlock(&iter);
-
+out:
+       bch2_trans_exit(&trans);
        return inum;
 }
 
-int bch2_empty_dir(struct bch_fs *c, u64 dir_inum)
+int bch2_empty_dir_trans(struct btree_trans *trans, u64 dir_inum)
 {
-       struct btree_iter iter;
+       struct btree_iter *iter;
        struct bkey_s_c k;
-       int ret = 0;
+       int ret;
 
-       for_each_btree_key(&iter, c, BTREE_ID_DIRENTS, POS(dir_inum, 0), 0, k) {
+       for_each_btree_key(trans, iter, BTREE_ID_DIRENTS,
+                          POS(dir_inum, 0), 0, k, ret) {
                if (k.k->p.inode > dir_inum)
                        break;
 
-               if (k.k->type == BCH_DIRENT) {
+               if (k.k->type == KEY_TYPE_dirent) {
                        ret = -ENOTEMPTY;
                        break;
                }
        }
-       bch2_btree_iter_unlock(&iter);
+       bch2_trans_iter_put(trans, iter);
 
        return ret;
 }
 
-int bch2_readdir(struct bch_fs *c, struct file *file,
-                struct dir_context *ctx)
+int bch2_readdir(struct bch_fs *c, u64 inum, struct dir_context *ctx)
 {
-       struct bch_inode_info *inode = file_bch_inode(file);
-       struct btree_iter iter;
+       struct btree_trans trans;
+       struct btree_iter *iter;
        struct bkey_s_c k;
        struct bkey_s_c_dirent dirent;
-       unsigned len;
-
-       if (!dir_emit_dots(file, ctx))
-               return 0;
+       int ret;
 
-       for_each_btree_key(&iter, c, BTREE_ID_DIRENTS,
-                          POS(inode->v.i_ino, ctx->pos), 0, k) {
-               if (k.k->type != BCH_DIRENT)
-                       continue;
+       bch2_trans_init(&trans, c, 0, 0);
 
-               dirent = bkey_s_c_to_dirent(k);
+       for_each_btree_key(&trans, iter, BTREE_ID_DIRENTS,
+                          POS(inum, ctx->pos), 0, k, ret) {
+               if (k.k->p.inode > inum)
+                       break;
 
-               if (bkey_cmp(k.k->p, POS(inode->v.i_ino, ctx->pos)) < 0)
+               if (k.k->type != KEY_TYPE_dirent)
                        continue;
 
-               if (k.k->p.inode > inode->v.i_ino)
-                       break;
-
-               len = bch2_dirent_name_bytes(dirent);
+               dirent = bkey_s_c_to_dirent(k);
 
                /*
                 * XXX: dir_emit() can fault and block, while we're holding
                 * locks
                 */
-               if (!dir_emit(ctx, dirent.v->d_name, len,
+               ctx->pos = dirent.k->p.offset;
+               if (!dir_emit(ctx, dirent.v->d_name,
+                             bch2_dirent_name_bytes(dirent),
                              le64_to_cpu(dirent.v->d_inum),
                              dirent.v->d_type))
                        break;
-
-               ctx->pos = k.k->p.offset + 1;
+               ctx->pos = dirent.k->p.offset + 1;
        }
-       bch2_btree_iter_unlock(&iter);
+       ret = bch2_trans_exit(&trans) ?: ret;
 
-       return 0;
+       return ret;
 }