René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Missing fields in fs struct results in downstream incorrect storage calculation","articleBody":"Per POSIX \u003csys/statvfs.h> ([ref](https://pubs.opengroup.org/onlinepubs/009695399/basedefs/sys/statvfs.h.html)), f_blocks, f_bfree, and f_bavail are defined as being \"in units of f_frsize\", not f_bsize. \n\nCurrently uv_statfs_t only exposes f_bsize, causing consumers to calculate incorrect disk space on filesystems where these values differ (macOS APFS, ZFS, CephFS, Docker Desktop virtiofs). \n\nI noticed this issue while debugging  [immich#4318](https://github.com/immich-app/immich/issues/4318). Immich [uses bsize](https://github.com/immich-app/immich/blob/3321c1a9dfa8f483cbb011cdb5617a3b0b61d239/server/src/repositories/storage.repository.ts#L173-L180) to calculate total, free and available disk space:\n\n```typescript\n  async checkDiskUsage(folder: string): Promise\u003cDiskUsage> {\n    const stats = await fs.statfs(folder);\n    return {\n      available: stats.bavail * stats.bsize,\n      free: stats.bfree * stats.bsize,\n      total: stats.blocks * stats.bsize,\n    };\n  }\n```\n\nThis confusion between bsize and frsize has caused bugs in multiple projects including [borgbackup#4289](https://github.com/borgbackup/borg/issues/4289), [cockroachdb#61182](https://github.com/cockroachdb/cockroach/issues/61182), and the fix is [straightforward](https://github.com/borgbackup/borg/commit/2db84eada026e95575591cb27fe682af6a7986d9). But it is not possible to fix on node without the right field being exposed.\n\n","author":{"url":"https://github.com/ezequielp","@type":"Person","name":"ezequielp"},"datePublished":"2026-01-01T17:40:33Z","url":"https://github.com/libuv/libuv/issues/4983"}