From 8aa1efa223d7bd39faaabdfbf85882ed3942a6f4 Mon Sep 17 00:00:00 2001 From: Cherry Mui Date: Sat, 11 Oct 2025 10:36:49 -0400 Subject: [PATCH] cmd/link: in TestFallocate, only check number of blocks on Darwin The number-of-blocks check was introduced when fixing a Darwin- specific bug. On Darwin, the file allocation syscall is a bit tricky. On Linux and BSDs, it is more straightforward and unlikely to go wrong. The test itself, on the other hand, is less reliable on Linux (and perhaps BSDs), as it is considered less portable and is an implementation detail of the file system. Given these two reasons, only check it on Darwin. Fixes #75795. Change-Id: I3da891fd60a141c3eca5d0f5ec20c2cad65b8862 Reviewed-on: https://go-review.googlesource.com/c/go/+/711095 LUCI-TryBot-Result: Go LUCI Reviewed-by: Keith Randall Reviewed-by: Keith Randall --- src/cmd/link/internal/ld/fallocate_test.go | 25 ++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/src/cmd/link/internal/ld/fallocate_test.go b/src/cmd/link/internal/ld/fallocate_test.go index 3c6b7ef752..f463b5b63b 100644 --- a/src/cmd/link/internal/ld/fallocate_test.go +++ b/src/cmd/link/internal/ld/fallocate_test.go @@ -10,6 +10,7 @@ import ( "errors" "os" "path/filepath" + "runtime" "syscall" "testing" ) @@ -53,12 +54,24 @@ func TestFallocate(t *testing.T) { if got := stat.Size(); got != sz { t.Errorf("unexpected file size: got %d, want %d", got, sz) } - // The number of blocks must be enough for the requested size. - // We used to require an exact match, but it appears that - // some file systems allocate a few extra blocks in some cases. - // See issue #41127. - if got, want := stat.Sys().(*syscall.Stat_t).Blocks, (sz+511)/512; got < want { - t.Errorf("unexpected disk usage: got %d blocks, want at least %d", got, want) + if runtime.GOOS == "darwin" { + // Check the number of allocated blocks on Darwin. On Linux (and + // perhaps BSDs), stat's Blocks field may not be portable as it + // is an implementation detail of the file system. On Darwin, it + // is documented as "the actual number of blocks allocated for + // the file in 512-byte units". + // The check is introduced when fixing a Darwin-specific bug. On + // Darwin, the file allocation syscall is a bit tricky. On Linux + // and BSDs, it is more straightforward and unlikely to go wrong. + // Given these two reasons, only check it on Darwin. + // + // The number of blocks must be enough for the requested size. + // We used to require an exact match, but it appears that + // some file systems allocate a few extra blocks in some cases. + // See issue #41127. + if got, want := stat.Sys().(*syscall.Stat_t).Blocks, (sz+511)/512; got < want { + t.Errorf("unexpected disk usage: got %d blocks, want at least %d", got, want) + } } out.munmap() } -- 2.52.0