Date: Tue, 14 Nov 2023 19:51:39 +0100 From: Mateusz Guzik <mjguzik@gmail.com> To: Alexander Motin <mav@freebsd.org> Cc: Ronald Klop <ronald-lists@klop.ws>, Konstantin Belousov <kostikbel@gmail.com>, current@freebsd.org Subject: Re: crash zfs_clone_range() Message-ID: <CAGudoHHOvOD6YSE_GxU=kK_euDjRmVo4t2XicAMRd6-sstWEOw@mail.gmail.com> In-Reply-To: <ca2b13ee-7144-96ce-78a2-118c7982de23@FreeBSD.org> References: <349700057.3452.1699611152405@localhost> <c9c8ab33-efce-5ed0-1f3f-311fa3cf1338@FreeBSD.org> <ZVEdyHFJyTg0cqCo@kib.kiev.ua> <1900239445.5968.1699966796547@localhost> <CAGudoHGdhaea9mkF3RZSCgXuEGNesb9AtkLXrYQNncgreYsv=g@mail.gmail.com> <ea3b2421-a07c-e7c2-68eb-908185dbb98f@FreeBSD.org> <ca2b13ee-7144-96ce-78a2-118c7982de23@FreeBSD.org>
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On 11/14/23, Alexander Motin <mav@freebsd.org> wrote:
> On 14.11.2023 12:44, Alexander Motin wrote:
>> On 14.11.2023 12:39, Mateusz Guzik wrote:
>>> One of the vnodes is probably not zfs, I suspect this will do it
>>> (untested):
>>>
>>> diff --git a/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vnops_os.c
>>> b/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vnops_os.c
>>> index 107cd69c756c..e799a7091b8e 100644
>>> --- a/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vnops_os.c
>>> +++ b/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vnops_os.c
>>> @@ -6270,6 +6270,11 @@ zfs_freebsd_copy_file_range(struct
>>> vop_copy_file_range_args *ap)
>>> goto bad_write_fallback;
>>> }
>>> }
>>> +
>>> + if (invp->v_mount->mnt_vfc != outvp->v_mount->mnt_vfc) {
>>> + goto bad_write_fallback;
>>> + }
>>> +
>>> if (invp == outvp) {
>>> if (vn_lock(outvp, LK_EXCLUSIVE) != 0) {
>>> goto bad_write_fallback;
>>>
>>
>> vn_copy_file_range() verifies for that:
>>
>> /*
>> * If the two vnodes are for the same file system type, call
>> * VOP_COPY_FILE_RANGE(), otherwise call
>> vn_generic_copy_file_range()
>> * which can handle copies across multiple file system types.
>> */
>> *lenp = len;
>> if (inmp == outmp || strcmp(inmp->mnt_vfc->vfc_name,
>> outmp->mnt_vfc->vfc_name) == 0)
>> error = VOP_COPY_FILE_RANGE(invp, inoffp, outvp,
>> outoffp,
>> lenp, flags, incred, outcred, fsize_td);
>> else
>> error = vn_generic_copy_file_range(invp, inoffp, outvp,
>> outoffp, lenp, flags, incred, outcred, fsize_td);
>
> Thinking again, what happen if there are two nullfs mounts on top of two
> different file systems, one of which is indeed not ZFS? Do we need to
> add those checks to all ZFS, NFS and FUSE, implementing
> VOP_COPY_FILE_RANGE, or it is responsibility of nullfs or VFS?
>
I already advocated for not trying to guess for filesystems what they
can or cannot handle internally.
That is to say vn_copy_file_range should call VOP_COPY_FILE_RANGE,
that can try to figure out what to do and if it got nothing punt to a
fallback. This already happens for some of the cases.
--
Mateusz Guzik <mjguzik gmail.com>
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