Formatting a file-backed NVMe device in bhyve fails because the blockif_candelete function returns FALSE on kernel which supports hole-punching: # uname -mrsvK FreeBSD 14.0-CURRENT FreeBSD 14.0-CURRENT main-81b22a9892 GENERIC amd64 1400041 This appears to happen because the cap_right_init(3) call does not allow the use of fpathconf(2). The attached patch which adds the CAP_FPATHCONF right fixes this.
Created attachment 229760 [details] patch to allow detection of hole-punching
Do you have an opened differential to that? LGTM. Ka Ho
Looks good to me also, I think the patch can simply be committed.
In the past, the bhyve process has strongly recommend code reviews. In that spirit https://reviews.freebsd.org/D33203
A commit in branch main references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=d8c1d7b6526c7063304cd1e938d12dec137454e2 commit d8c1d7b6526c7063304cd1e938d12dec137454e2 Author: Chuck Tuffli <chuck@FreeBSD.org> AuthorDate: 2021-12-01 05:07:32 +0000 Commit: Chuck Tuffli <chuck@FreeBSD.org> CommitDate: 2021-12-01 05:49:34 +0000 bhyve blockif: fix blockif_candelete with Capsicum NVMe conformance tests for the Format command failed if the backing-storage for the bhyve device was a file instead of a Zvol. The tests (and the specification) expect a Format to destroy all previously written data. The bhyve NVMe emulation implements this by trimming / deallocating all data from the backing-storage. The blockif_candelete() function indicated the file did not support deallocation (i.e. fpathconf(..., _PC_DEALLOC_PRESENT) returned FALSE) even though the kernel supported file hole punching. This occurs on builds with Capsicum enabled because blockif did not allow the fpathconf(2) right. Fix is to add CAP_FPATHCONF to the cap_rights_init(3) call. PR: 260081 Reviewed by: allanjude, markj, jhb MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D33203 usr.sbin/bhyve/block_if.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
A commit in branch stable/13 references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=1685d8368c2f78012f6d2d045f29193156a8580d commit 1685d8368c2f78012f6d2d045f29193156a8580d Author: Chuck Tuffli <chuck@FreeBSD.org> AuthorDate: 2021-12-01 05:07:32 +0000 Commit: Chuck Tuffli <chuck@FreeBSD.org> CommitDate: 2022-02-22 03:23:16 +0000 bhyve blockif: fix blockif_candelete with Capsicum NVMe conformance tests for the Format command failed if the backing-storage for the bhyve device was a file instead of a Zvol. The tests (and the specification) expect a Format to destroy all previously written data. The bhyve NVMe emulation implements this by trimming / deallocating all data from the backing-storage. The blockif_candelete() function indicated the file did not support deallocation (i.e. fpathconf(..., _PC_DEALLOC_PRESENT) returned FALSE) even though the kernel supported file hole punching. This occurs on builds with Capsicum enabled because blockif did not allow the fpathconf(2) right. Fix is to add CAP_FPATHCONF to the cap_rights_init(3) call. PR: 260081 (cherry picked from commit d8c1d7b6526c7063304cd1e938d12dec137454e2) usr.sbin/bhyve/block_if.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Can this be closed now?
(In reply to Chuck Tuffli from comment #7) Looks like it, yes.