On Thu, Aug 29, 2024 at 09:26:39AM -0400, Jeff Layton wrote:
> From: NeilBrown <neilb@xxxxxxx>
>
> It is not safe to dereference fl->c.flc_owner without first confirming
> fl->fl_lmops is the expected manager. nfsd4_deleg_getattr_conflict()
> tests fl_lmops but largely ignores the result and assumes that flc_owner
> is an nfs4_delegation anyway. This is wrong.
>
> With this patch we restore the "!= &nfsd_lease_mng_ops" case to behave
> as it did before the changed mentioned below. This the same as the
> current code, but without any reference to a possible delegation.
>
> Fixes: c5967721e106 ("NFSD: handle GETATTR conflict with write delegation")
> Signed-off-by: NeilBrown <neilb@xxxxxxx>
> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
I've already applied this to nfsd-fixes.
If I include this commit in both nfsd-fixes and nfsd-next then the
linux-next merge whines about duplicate patches. Stephen Rothwell
suggested git-merging nfsd-fixes and nfsd-next but I'm not quite
confident enough to try that.
Barring another solution, merging this series will have to wait a
few days before the two trees can sync up.
> ---
> fs/nfsd/nfs4state.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index b6bf39c64d78..eaa11d42d1b1 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -8854,7 +8854,15 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct dentry *dentry,
> */
> if (type == F_RDLCK)
> break;
> - goto break_lease;
> +
> + nfsd_stats_wdeleg_getattr_inc(nn);
> + spin_unlock(&ctx->flc_lock);
> +
> + status = nfserrno(nfsd_open_break_lease(inode, NFSD_MAY_READ));
> + if (status != nfserr_jukebox ||
> + !nfsd_wait_for_delegreturn(rqstp, inode))
> + return status;
> + return 0;
> }
> if (type == F_WRLCK) {
> struct nfs4_delegation *dp = fl->c.flc_owner;
> @@ -8863,7 +8871,6 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct dentry *dentry,
> spin_unlock(&ctx->flc_lock);
> return 0;
> }
> -break_lease:
> nfsd_stats_wdeleg_getattr_inc(nn);
> dp = fl->c.flc_owner;
> refcount_inc(&dp->dl_stid.sc_count);
>
> --
> 2.46.0
>
--
Chuck Lever
