diff options
| author | Benny Halevy <bhalevy@primarydata.com> | 2014-05-30 09:09:27 -0400 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2014-06-04 15:41:52 -0400 |
| commit | 931ee56c67573eb4e51c8a4e78598d965b8b059e (patch) | |
| tree | c9a2dd61a536acd1110ee611c1996cd6b57783ac /fs/nfsd | |
| parent | a832e7ae8b4f71fc522089d83fd445693aa7dbc5 (diff) | |
nfsd4: use recall_lock for delegation hashing
This fixes a bug in the handling of the fi_delegations list.
nfs4_setlease does not hold the recall_lock when adding to it. The
client_mutex is held, which prevents against concurrent list changes,
but nfsd_break_deleg_cb does not hold while walking it. New delegations
could theoretically creep onto the list while we're walking it there.
Signed-off-by: Benny Halevy <bhalevy@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'fs/nfsd')
| -rw-r--r-- | fs/nfsd/nfs4state.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 01a0e4384500..05ca64c4599d 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -433,12 +433,21 @@ static void unhash_stid(struct nfs4_stid *s) s->sc_type = 0; } +static void +hash_delegation_locked(struct nfs4_delegation *dp, struct nfs4_file *fp) +{ + lockdep_assert_held(&recall_lock); + + list_add(&dp->dl_perfile, &fp->fi_delegations); + list_add(&dp->dl_perclnt, &dp->dl_stid.sc_client->cl_delegations); +} + /* Called under the state lock. */ static void unhash_delegation(struct nfs4_delegation *dp) { - list_del_init(&dp->dl_perclnt); spin_lock(&recall_lock); + list_del_init(&dp->dl_perclnt); list_del_init(&dp->dl_perfile); list_del_init(&dp->dl_recall_lru); spin_unlock(&recall_lock); @@ -3065,11 +3074,12 @@ static int nfs4_setlease(struct nfs4_delegation *dp) status = vfs_setlease(fl->fl_file, fl->fl_type, &fl); if (status) goto out_free; - list_add(&dp->dl_perclnt, &dp->dl_stid.sc_client->cl_delegations); fp->fi_lease = fl; fp->fi_deleg_file = get_file(fl->fl_file); atomic_set(&fp->fi_delegees, 1); - list_add(&dp->dl_perfile, &fp->fi_delegations); + spin_lock(&recall_lock); + hash_delegation_locked(dp, fp); + spin_unlock(&recall_lock); return 0; out_free: locks_free_lock(fl); @@ -3090,9 +3100,8 @@ static int nfs4_set_delegation(struct nfs4_delegation *dp, struct nfs4_file *fp) spin_unlock(&recall_lock); return -EAGAIN; } - list_add(&dp->dl_perfile, &fp->fi_delegations); + hash_delegation_locked(dp, fp); spin_unlock(&recall_lock); - list_add(&dp->dl_perclnt, &dp->dl_stid.sc_client->cl_delegations); return 0; } @@ -4903,6 +4912,7 @@ static u64 nfsd_find_all_delegations(struct nfs4_client *clp, u64 max, struct nfs4_delegation *dp, *next; u64 count = 0; + lockdep_assert_held(&recall_lock); list_for_each_entry_safe(dp, next, &clp->cl_delegations, dl_perclnt) { if (victims) list_move(&dp->dl_recall_lru, victims); |