posix_fallocate not supported #4464
Description
error: unsupported operation: can't call foreign function `posix_fallocate` on OS `linux`
--> /home/nazar-pc/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/fs2-0.4.3/src/unix.rs:103:24
|
103 | let ret = unsafe { libc::posix_fallocate(file.as_raw_fd(), 0, len as libc::off_t) };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unsupported operation occurred here
|
= help: this means the program tried to do something Miri does not support; it does not indicate a bug in the program
= note: BACKTRACE on thread `tests::other_op`:
= note: inside `fs2::unix::allocate` at /home/nazar-pc/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/fs2-0.4.3/src/unix.rs:103:24: 103:86
= note: inside `<std::fs::File as fs2::FileExt>::allocate` at /home/nazar-pc/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/fs2-0.4.3/src/lib.rs:104:9: 104:33
It is meant to pre-allocate disk space to ensure writes do not fail within provided length with lack of disk space afterward. I'd say it is mostly the same as File::set_len() except it avoids sparse files on disk.