From 231cc20195294c9774ab68f523dd06059f4b0a5c Mon Sep 17 00:00:00 2001 From: =?utf8?q?P=C3=A1draig=20Brady?= Date: Wed, 29 Oct 2025 23:41:55 +0000 Subject: [PATCH] copy: avoid posix_fadvise bypassing copy offload behavior * src/copy-file-data.c (): pass 0 to posix_fadvise to indicate to EOF. coreutils 9.8 used OFF_T_MAX instead, which triggered OpenZFS 2.2.2 at least to synchronously (decompress and) populate the page cache. Addresses https://github.com/coreutils/coreutils/issues/122 --- src/copy-file-data.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/src/copy-file-data.c b/src/copy-file-data.c index 1eefd3071f..9eb6f47244 100644 --- a/src/copy-file-data.c +++ b/src/copy-file-data.c @@ -536,9 +536,12 @@ copy_file_data (int ifd, struct stat const *ist, off_t ipos, char const *iname, && scantype != PLAIN_SCANTYPE))); /* Don't bother calling fadvise for small copies, as it is not - likely to help performance and might even hurt it. */ + likely to help performance and might even hurt it. + Note it's important to use a 0 length to indicate the whole file + as OpenZFS 2.2.2 at least will otherwise synchronously + (decompress and) populate the cache when given a specific length. */ if (IO_BUFSIZE < ibytes) - fdadvise (ifd, ipos, ibytes <= OFF_T_MAX - ipos ? ibytes : 0, + fdadvise (ifd, ipos, ibytes < OFF_T_MAX - ipos ? ibytes : 0, FADVISE_SEQUENTIAL); /* If not making a sparse file, try to use a more-efficient -- 2.47.3