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Nonsense UNKNOWN error when writing large buffers with fs.writev #40779
Description
Version
14.18.1
Platform
Linux ops 5.11.0-1021-gcp #23~20.04.1-Ubuntu SMP Fri Oct 1 19:04:32 UTC 2021 x86_64 x86_64 x86_64 GNU/Linu
Subsystem
fs
What steps will reproduce the bug?
const fs = require("fs");
const fd = fs.openSync("./test.dat", fs.constants.O_WRONLY | fs.constants.O_CREAT, 0o666);
const bufs = [Buffer.alloc(0x7FFFFFFF + 1)];
fs.writevSync(fd, bufs, 0);This throws
Uncaught Error: UNKNOWN: unknown error, write
at Object.writevSync (fs.js:749:3) {
errno: -2147483648,
syscall: 'write',
code: 'UNKNOWN'
}
That errno is 0x7fffffff + 1 wrapped around.
How often does it reproduce? Is there a required condition?
Always.
What is the expected behavior?
Should either work, since pwritev(2) works (I don't know if it has a limit less than SSIZE_MAX), or report a proper error before making the syscall. I did the latter recently for fs.write in c4e7dca. It would be nice if large files actually worked, but the best fix for that would require a new libuv function.
What do you see instead?
No response
Additional information
No response
Activity
github-actions commentedon Jun 26, 2026
This issue has been marked as stale due to 210 days of inactivity.
It will be automatically closed in 30 days if no further activity occurs. If this is still relevant, please leave a comment or update it to keep it open.
zbjornson commentedon Jun 27, 2026
Still relevant, and I see related upstream activity in libuv in March!
github-actions commentedon Sep 26, 2026
This issue has been marked as stale due to 90 days of inactivity.
It will be automatically closed in 30 days if no further activity occurs. If this is still relevant, please leave a comment or update it to keep it open.