[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Virtio-fs] [PATCH v2 1/2] virtiofsd: Save error code early at the f
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Virtio-fs] [PATCH v2 1/2] virtiofsd: Save error code early at the failure callsite |
Date: |
Mon, 8 Feb 2021 17:05:05 +0000 |
User-agent: |
Mutt/1.14.6 (2020-07-11) |
* Vivek Goyal (vgoyal@redhat.com) wrote:
> Change error code handling slightly in lo_setattr(). Right now we seem
> to jump to out_err and assume that "errno" is valid and use that to
> send reply.
>
> But if caller has to do some other operations before jumping to out_err,
> then it does the dance of first saving errno to saverr and the restore
> errno before jumping to out_err. This makes it more confusing.
>
> I am about to make more changes where caller will have to do some
> work after error before jumping to out_err. I found it easier to
> change the convention a bit. That is caller saves error in "saverr"
> before jumping to out_err. And out_err uses "saverr" to send error
> back and does not rely on "errno" having actual error.
>
> Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Yes, that looks OK, so
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
but please can you send a rebased version, Stefan's recent
security fix changes it around the openat.
Dave
> ---
> tools/virtiofsd/passthrough_ll.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/tools/virtiofsd/passthrough_ll.c
> b/tools/virtiofsd/passthrough_ll.c
> index ec1008bceb..6407b1a2e1 100644
> --- a/tools/virtiofsd/passthrough_ll.c
> +++ b/tools/virtiofsd/passthrough_ll.c
> @@ -686,6 +686,7 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino,
> struct stat *attr,
> res = fchmodat(lo->proc_self_fd, procname, attr->st_mode, 0);
> }
> if (res == -1) {
> + saverr = errno;
> goto out_err;
> }
> }
> @@ -695,6 +696,7 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino,
> struct stat *attr,
>
> res = fchownat(ifd, "", uid, gid, AT_EMPTY_PATH |
> AT_SYMLINK_NOFOLLOW);
> if (res == -1) {
> + saverr = errno;
> goto out_err;
> }
> }
> @@ -707,15 +709,15 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino,
> struct stat *attr,
> sprintf(procname, "%i", ifd);
> truncfd = openat(lo->proc_self_fd, procname, O_RDWR);
> if (truncfd < 0) {
> + saverr = errno;
> goto out_err;
> }
> }
>
> res = ftruncate(truncfd, attr->st_size);
> + saverr = res == -1 ? errno : 0;
> if (!fi) {
> - saverr = errno;
> close(truncfd);
> - errno = saverr;
> }
> if (res == -1) {
> goto out_err;
> @@ -748,6 +750,7 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino,
> struct stat *attr,
> res = utimensat(lo->proc_self_fd, procname, tv, 0);
> }
> if (res == -1) {
> + saverr = errno;
> goto out_err;
> }
> }
> @@ -756,7 +759,6 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino,
> struct stat *attr,
> return lo_getattr(req, ino, fi);
>
> out_err:
> - saverr = errno;
> lo_inode_put(lo, &inode);
> fuse_reply_err(req, saverr);
> }
> --
> 2.25.4
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- Re: [Virtio-fs] [PATCH v2 1/2] virtiofsd: Save error code early at the failure callsite,
Dr. David Alan Gilbert <=