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| author | Trond Myklebust <trond.myklebust@primarydata.com> | 2017-11-03 15:00:16 +0300 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2017-11-28 00:45:10 +0300 |
| commit | 03da3169c67f67729d8b52cee4e5689b0a3f94c0 (patch) | |
| tree | 3298b80d391fa2ac9e082534850ba7d3a925cdc3 /fs/nfsd | |
| parent | 9271d7e509c1bfc0b9a418caec29ec8d1ac38270 (diff) | |
| download | linux-03da3169c67f67729d8b52cee4e5689b0a3f94c0.tar.xz | |
nfsd: Fix races with check_stateid_generation()
The various functions that call check_stateid_generation() in order
to compare a client-supplied stateid with the nfs4_stid state, usually
need to atomically check for closed state. Those that perform the
check after locking the st_mutex using nfsd4_lock_ol_stateid()
should now be OK, but we do want to fix up the others.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'fs/nfsd')
| -rw-r--r-- | fs/nfsd/nfs4state.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index da07c24e9372..ecb803d7c966 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -4906,6 +4906,18 @@ static __be32 check_stateid_generation(stateid_t *in, stateid_t *ref, bool has_s return nfserr_old_stateid; } +static __be32 nfsd4_stid_check_stateid_generation(stateid_t *in, struct nfs4_stid *s, bool has_session) +{ + __be32 ret; + + spin_lock(&s->sc_lock); + ret = nfsd4_verify_open_stid(s); + if (ret == nfs_ok) + ret = check_stateid_generation(in, &s->sc_stateid, has_session); + spin_unlock(&s->sc_lock); + return ret; +} + static __be32 nfsd4_check_openowner_confirmed(struct nfs4_ol_stateid *ols) { if (ols->st_stateowner->so_is_open_owner && @@ -4934,7 +4946,7 @@ static __be32 nfsd4_validate_stateid(struct nfs4_client *cl, stateid_t *stateid) s = find_stateid_locked(cl, stateid); if (!s) goto out_unlock; - status = check_stateid_generation(stateid, &s->sc_stateid, 1); + status = nfsd4_stid_check_stateid_generation(stateid, s, 1); if (status) goto out_unlock; switch (s->sc_type) { @@ -5095,7 +5107,7 @@ nfs4_preprocess_stateid_op(struct svc_rqst *rqstp, &s, nn); if (status) return status; - status = check_stateid_generation(stateid, &s->sc_stateid, + status = nfsd4_stid_check_stateid_generation(stateid, s, nfsd4_has_session(cstate)); if (status) goto out; @@ -5188,6 +5200,7 @@ nfsd4_free_stateid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, s = find_stateid_locked(cl, stateid); if (!s) goto out_unlock; + spin_lock(&s->sc_lock); switch (s->sc_type) { case NFS4_DELEG_STID: ret = nfserr_locks_held; @@ -5199,11 +5212,13 @@ nfsd4_free_stateid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, ret = nfserr_locks_held; break; case NFS4_LOCK_STID: + spin_unlock(&s->sc_lock); refcount_inc(&s->sc_count); spin_unlock(&cl->cl_lock); ret = nfsd4_free_lock_stateid(stateid, s); goto out; case NFS4_REVOKED_DELEG_STID: + spin_unlock(&s->sc_lock); dp = delegstateid(s); list_del_init(&dp->dl_recall_lru); spin_unlock(&cl->cl_lock); @@ -5212,6 +5227,7 @@ nfsd4_free_stateid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, goto out; /* Default falls through and returns nfserr_bad_stateid */ } + spin_unlock(&s->sc_lock); out_unlock: spin_unlock(&cl->cl_lock); out: @@ -5491,7 +5507,7 @@ nfsd4_delegreturn(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, if (status) goto out; dp = delegstateid(s); - status = check_stateid_generation(stateid, &dp->dl_stid.sc_stateid, nfsd4_has_session(cstate)); + status = nfsd4_stid_check_stateid_generation(stateid, &dp->dl_stid, nfsd4_has_session(cstate)); if (status) goto put_stateid; |