On Thu, 07 Nov 2024, cel@xxxxxxxxxx wrote:
> From: Chuck Lever <chuck.lever@xxxxxxxxxx>
>
> I noticed that recently, simple operations like "make" started
> failing on NFSv3 mounts of ext4 exports. Network capture shows that
> READDIRPLUS operated correctly but READDIR failed with
> NFS3ERR_INVAL. The vfs_llseek() call returned EINVAL when it is
> passed a non-zero starting directory cookie.
>
> I bisected to commit c689bdd3bffa ("nfsd: further centralize
> protocol version checks.").
>
> Turns out that nfsd3_proc_readdir() does not call fh_verify() before
> it calls nfsd_readdir(), so the new fhp->fh_64bit_cookies boolean is
> not set properly. This leaves the NFSD_MAY_64BIT_COOKIE unset when
> the directory is opened.
>
> For ext4, this causes the wrong "max file size" value to be used
> when sanity checking the incoming directory cookie (which is a seek
> offset value).
>
> The fhp->fh_64bit_cookies boolean is /always/ properly initialized
> after nfsd_open() returns. There doesn't seem to be a reason for the
> generic NFSD open helper to handle the f_mode fix-up for
> directories, so just move that to the one caller that tries to open
> an S_IFDIR with NFSD_MAY_64BIT_COOKIE.
Thanks. Looks good. I like that you moved the f_mode setting out of
nfsd_open(). It really is only needed for directories.
Reviewed-by: NeilBrown <neilb@xxxxxxx>
NeilBrown
>
> Suggested-by: NeilBrown <neilb@xxxxxxx>
> Fixes: c689bdd3bffa ("nfsd: further centralize protocol version checks.")
> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> ---
> fs/nfsd/vfs.c | 13 +++++--------
> 1 file changed, 5 insertions(+), 8 deletions(-)
>
> I'd like to get rolling with CI on this fix so it can go into
> v6.12-rc this week, so I authored this version based on Neil's
> suggestion.
>
> Note that removing the NFSD_MAY_64BIT_COOKIE flag entirely conflicts
> with the addition of NFSD_MAY_LOCALIO in v6.13. I've postponed the
> clean-up parts of this patch until then to help make merging this
> fix more smooth.
>
>
> diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
> index 22325b590e17..d6d4f2a0e898 100644
> --- a/fs/nfsd/vfs.c
> +++ b/fs/nfsd/vfs.c
> @@ -903,11 +903,6 @@ __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
> goto out;
> }
>
> - if (may_flags & NFSD_MAY_64BIT_COOKIE)
> - file->f_mode |= FMODE_64BITHASH;
> - else
> - file->f_mode |= FMODE_32BITHASH;
> -
> *filp = file;
> out:
> return host_err;
> @@ -2174,13 +2169,15 @@ nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
> loff_t offset = *offsetp;
> int may_flags = NFSD_MAY_READ;
>
> - if (fhp->fh_64bit_cookies)
> - may_flags |= NFSD_MAY_64BIT_COOKIE;
> -
> err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
> if (err)
> goto out;
>
> + if (fhp->fh_64bit_cookies)
> + file->f_mode |= FMODE_64BITHASH;
> + else
> + file->f_mode |= FMODE_32BITHASH;
> +
> offset = vfs_llseek(file, offset, SEEK_SET);
> if (offset < 0) {
> err = nfserrno((int)offset);
> --
> 2.47.0
>
>
