Bug/Performance: sendfile() loop treats EAGAIN / EINTR as fatal errors #168

New Issue

2026-07-29T18:36:33+02:00

TapTap commented

2026-07-29 18:36:33 +02:00

Description

file_send_sendfile() in src/shared/file.c:456-463 calls sendfile() in a loop. If sendfile() returns -1 with errno == EAGAIN or EINTR, the function treats it as a fatal error and returns false. On a non-blocking or busy socket, this can cause unnecessary transfer failures. The function also does not use errno correctly to distinguish recoverable errors from true failures.

Location

src/shared/file.c:458-463 — sendfile() loop.

Suggested fix

Check errno after sendfile() returns -1.
Retry on EAGAIN (after poll()/select() for write readiness) and EINTR.
Use sendfile() only for regular files; fall back to read()/write() for non-regular files.

Severity

Low

Category

bug, performance

This issue was automatically generated by the issue-creator agent.

## Description `file_send_sendfile()` in `src/shared/file.c:456-463` calls `sendfile()` in a loop. If `sendfile()` returns `-1` with `errno == EAGAIN` or `EINTR`, the function treats it as a fatal error and returns false. On a non-blocking or busy socket, this can cause unnecessary transfer failures. The function also does not use `errno` correctly to distinguish recoverable errors from true failures. ## Location - `src/shared/file.c:458-463` — `sendfile()` loop. ## Suggested fix 1. Check `errno` after `sendfile()` returns `-1`. 2. Retry on `EAGAIN` (after `poll()`/select() for write readiness) and `EINTR`. 3. Use `sendfile()` only for regular files; fall back to `read()`/`write()` for non-regular files. ## Severity Low ## Category bug, performance --- _This issue was automatically generated by the issue-creator agent._

TapTap added the bug needs-triage performance labels 2026-07-29 18:36:33 +02:00

TapTap referenced this issue from a commit

2026-07-29 19:02:14 +02:00

fix: resolve all bug issues (#158, #163, #164, #165, #166, #167, #168, #169)

TapTap referenced this issue from a commit

2026-07-29 19:11:17 +02:00

fix: resolve all bug issues (#158, #163, #164, #165, #166, #167, #168, #169)

TapTap referenced this issue

2026-07-29 19:29:55 +02:00

Comprehensive fix: security, bugs, refactoring, tests, and rsync parity features #173

TapTap closed this issue

2026-07-30 18:17:32 +02:00