crl-release-22.2: vfs: default to Unix semantics in MemFS

[jbowens]

Backport of #2065. Informs cockroachdb/cockroach#112087.

---

Default to Unix semantics in MemFS. The Windows semantics are left as configurable for unit tests that seek to ensure we don't remove open files, when possible.

There are existing cases where we cannot satisfy Windows semantics, and Go does not support opening files with the appropriate FILE_SHARE_DELETE permission bit (see golang/go#34681, golang/go#32088). The MemFS's implementation of Windows semantics is useful for ensuring we don't regress in the cases where we can satisfy Windows semantics.

Close #2064.
Informs #1236.

[cockroach-teamcity]

This change is 

[jbowens]

Windows build failed (and has been failing on crl-release-22.2 HEAD) with:

2023-10-16T16:05:40.0230279Z # github.com/cockroachdb/pebble/internal/cache.test
2023-10-16T16:05:40.0335546Z C:\hostedtoolcache\windows\go\1.18.10\x64\pkg\tool\windows_amd64\link.exe: running gcc failed: exit status 1
2023-10-16T16:05:40.0342402Z C:/ProgramData/Chocolatey/lib/mingw/tools/install/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\RUNNER~1\AppData\Local\Temp\go-link-3311659118\000005.o: in function `_cgo_preinit_init':
2023-10-16T16:05:40.0347973Z \\_\_\runtime\cgo/gcc_libinit_windows.c:30: undefined reference to `__imp___iob_func'
2023-10-16T16:05:40.0351671Z C:/ProgramData/Chocolatey/lib/mingw/tools/install/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\RUNNER~1\AppData\Local\Temp\go-link-3311659118\000005.o: in function `x_cgo_sys_thread_create':
2023-10-16T16:05:40.0357241Z \\_\_\runtime\cgo/gcc_libinit_windows.c:60: undefined reference to `__imp___iob_func'
2023-10-16T16:05:40.0367924Z C:/ProgramData/Chocolatey/lib/mingw/tools/install/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\RUNNER~1\AppData\Local\Temp\go-link-3311659118\000005.o: in function `x_cgo_notify_runtime_init_done':
2023-10-16T16:05:40.0375064Z \\_\_\runtime\cgo/gcc_libinit_windows.c:101: undefined reference to `__imp___iob_func'
2023-10-16T16:05:40.0380608Z C:/ProgramData/Chocolatey/lib/mingw/tools/install/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\RUNNER~1\AppData\Local\Temp\go-link-3311659118\000006.o: in function `x_cgo_thread_start':
2023-10-16T16:05:40.0532719Z \\_\_\runtime\cgo/gcc_util.c:18: undefined reference to `__imp___iob_func'
2023-10-16T16:05:40.0539696Z C:/ProgramData/Chocolatey/lib/mingw/tools/install/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\RUNNER~1\AppData\Local\Temp\go-link-3311659118\000007.o: in function `_cgo_sys_thread_start':
2023-10-16T16:05:40.0545287Z \\_\_\runtime\cgo/gcc_windows_amd64.c:31: undefined reference to `__imp___iob_func'
2023-10-16T16:05:40.0548778Z collect2.exe: error: ld returned 1 exit status
2023-10-16T16:05:40.0588004Z 
2023-10-16T16:06:29.9697827Z # github.com/cockroachdb/pebble.test
2023-10-16T16:06:29.9699280Z C:\hostedtoolcache\windows\go\1.18.10\x64\pkg\tool\windows_amd64\link.exe: running gcc failed: exit status 1
2023-10-16T16:06:29.9703015Z C:/ProgramData/Chocolatey/lib/mingw/tools/install/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\RUNNER~1\AppData\Local\Temp\go-link-726652978\000047.o: in function `_cgo_preinit_init':
2023-10-16T16:06:29.9705794Z \\_\_\runtime\cgo/gcc_libinit_windows.c:30: undefined reference to `__imp___iob_func'
2023-10-16T16:06:29.9708920Z C:/ProgramData/Chocolatey/lib/mingw/tools/install/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\RUNNER~1\AppData\Local\Temp\go-link-726652978\000047.o: in function `x_cgo_sys_thread_create':
2023-10-16T16:06:29.9711632Z \\_\_\runtime\cgo/gcc_libinit_windows.c:60: undefined reference to `__imp___iob_func'
2023-10-16T16:06:29.9714822Z C:/ProgramData/Chocolatey/lib/mingw/tools/install/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\RUNNER~1\AppData\Local\Temp\go-link-726652978\000047.o: in function `x_cgo_notify_runtime_init_done':
2023-10-16T16:06:29.9717619Z \\_\_\runtime\cgo/gcc_libinit_windows.c:101: undefined reference to `__imp___iob_func'
2023-10-16T16:06:29.9720651Z C:/ProgramData/Chocolatey/lib/mingw/tools/install/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\RUNNER~1\AppData\Local\Temp\go-link-726652978\000048.o: in function `x_cgo_thread_start':
2023-10-16T16:06:29.9723233Z \\_\_\runtime\cgo/gcc_util.c:18: undefined reference to `__imp___iob_func'
2023-10-16T16:06:29.9726190Z C:/ProgramData/Chocolatey/lib/mingw/tools/install/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\RUNNER~1\AppData\Local\Temp\go-link-726652978\000049.o: in function `_cgo_sys_thread_start':
2023-10-16T16:06:29.9728901Z \\_\_\runtime\cgo/gcc_windows_amd64.c:31: undefined reference to `__imp___iob_func'
2023-10-16T16:06:29.9730032Z collect2.exe: error: ld returned 1 exit status

[jbowens]

Investigating a fix to that separately in #3001.

[RaduBerinde]

Reviewable status: 0 of 2 files reviewed, 1 unresolved discussion (waiting on @jbowens and @sumeerbhola)

---

vfs/mem_fs.go line 93 at r1 (raw file):

// semantics, in particular with respect to whether any of an open file's links
// may be removed. Windows semantics default to off.
func (y *MemFS) UseWindowsSemantics(windowsSemantics bool) {

[nit] I don't think we need the argument, we can just make it turn it on always.

[jbowens]

TFTR!

Reviewable status: 0 of 2 files reviewed, 1 unresolved discussion (waiting on @RaduBerinde and @sumeerbhola)

---

vfs/mem_fs.go line 93 at r1 (raw file):

Previously, RaduBerinde wrote…

[nit] I don't think we need the argument, we can just make it turn it on always.

True — I'm going to leave it to maintain an identical backport commit, but we can definitely change it on master.