diff options
| author | NeilBrown <neilb@suse.de> | 2024-08-29 09:06:28 +1000 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2024-08-30 10:48:29 -0400 |
| commit | 40927f3d0972bf86357a32a5749be71a551241b6 (patch) | |
| tree | a3976040195a7c51a63109716348d3709e6da840 | |
| parent | 7e8ae8486e4471513e2111aba6ac29f2357bed2a (diff) | |
| download | lwn-40927f3d0972bf86357a32a5749be71a551241b6.tar.gz lwn-40927f3d0972bf86357a32a5749be71a551241b6.zip | |
nfsd: fix nfsd4_deleg_getattr_conflict in presence of third party lease
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 change mentioned below. This is 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@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
| -rw-r--r-- | fs/nfsd/nfs4state.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 07f2496850c4..a366fb1c1b9b 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -8859,7 +8859,15 @@ 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; @@ -8868,7 +8876,6 @@ 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); |