From 1c755dc1ada95adc9aa41102baada73659397b80 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 29 Jul 2014 21:34:12 -0400 Subject: [PATCH] nfsd: Add locking to protect the state owner lists Change to using the clp->cl_lock for this. For now, there's a lot of cl_lock thrashing, but in later patches we'll eliminate that and close the potential races that can occur when releasing the cl_lock while walking the lists. For now, the client_mutex prevents those races. Signed-off-by: Trond Myklebust Signed-off-by: Jeff Layton Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 8ce5894133aa..3ac6e2fdabe5 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -893,6 +893,8 @@ static void unhash_generic_stateid(struct nfs4_ol_stateid *stp) { struct nfs4_file *fp = stp->st_stid.sc_file; + lockdep_assert_held(&stp->st_stateowner->so_client->cl_lock); + spin_lock(&fp->fi_lock); list_del(&stp->st_perfile); spin_unlock(&fp->fi_lock); @@ -921,9 +923,13 @@ static void nfs4_free_lock_stateid(struct nfs4_stid *stid) static void __release_lock_stateid(struct nfs4_ol_stateid *stp) { + struct nfs4_openowner *oo = openowner(stp->st_openstp->st_stateowner); + + spin_lock(&oo->oo_owner.so_client->cl_lock); list_del(&stp->st_locks); unhash_generic_stateid(stp); unhash_stid(&stp->st_stid); + spin_unlock(&oo->oo_owner.so_client->cl_lock); nfs4_put_stid(&stp->st_stid); } @@ -967,20 +973,26 @@ static void release_lock_stateid(struct nfs4_ol_stateid *stp) } static void release_open_stateid_locks(struct nfs4_ol_stateid *open_stp) + __releases(&open_stp->st_stateowner->so_client->cl_lock) + __acquires(&open_stp->st_stateowner->so_client->cl_lock) { struct nfs4_ol_stateid *stp; while (!list_empty(&open_stp->st_locks)) { stp = list_entry(open_stp->st_locks.next, struct nfs4_ol_stateid, st_locks); + spin_unlock(&open_stp->st_stateowner->so_client->cl_lock); release_lock_stateid(stp); + spin_lock(&open_stp->st_stateowner->so_client->cl_lock); } } static void unhash_open_stateid(struct nfs4_ol_stateid *stp) { + spin_lock(&stp->st_stateowner->so_client->cl_lock); unhash_generic_stateid(stp); release_open_stateid_locks(stp); + spin_unlock(&stp->st_stateowner->so_client->cl_lock); } static void release_open_stateid(struct nfs4_ol_stateid *stp) @@ -2996,16 +3008,18 @@ static void init_open_stateid(struct nfs4_ol_stateid *stp, struct nfs4_file *fp, stp->st_stid.sc_type = NFS4_OPEN_STID; INIT_LIST_HEAD(&stp->st_locks); - list_add(&stp->st_perstateowner, &oo->oo_owner.so_stateids); stp->st_stateowner = &oo->oo_owner; get_nfs4_file(fp); stp->st_stid.sc_file = fp; stp->st_access_bmap = 0; stp->st_deny_bmap = 0; stp->st_openstp = NULL; + spin_lock(&oo->oo_owner.so_client->cl_lock); + list_add(&stp->st_perstateowner, &oo->oo_owner.so_stateids); spin_lock(&fp->fi_lock); list_add(&stp->st_perfile, &fp->fi_stateids); spin_unlock(&fp->fi_lock); + spin_unlock(&oo->oo_owner.so_client->cl_lock); } static void @@ -4711,6 +4725,7 @@ alloc_init_lock_stateid(struct nfs4_lockowner *lo, struct nfs4_file *fp, struct nfs4_ol_stateid *open_stp) { struct nfs4_stid *s; + struct nfs4_openowner *oo = openowner(open_stp->st_stateowner); struct nfs4_ol_stateid *stp; struct nfs4_client *clp = lo->lo_owner.so_client; @@ -4719,7 +4734,6 @@ alloc_init_lock_stateid(struct nfs4_lockowner *lo, struct nfs4_file *fp, return NULL; stp = openlockstateid(s); stp->st_stid.sc_type = NFS4_LOCK_STID; - list_add(&stp->st_perstateowner, &lo->lo_owner.so_stateids); stp->st_stateowner = &lo->lo_owner; get_nfs4_file(fp); stp->st_stid.sc_file = fp; @@ -4727,10 +4741,13 @@ alloc_init_lock_stateid(struct nfs4_lockowner *lo, struct nfs4_file *fp, stp->st_access_bmap = 0; stp->st_deny_bmap = open_stp->st_deny_bmap; stp->st_openstp = open_stp; + spin_lock(&oo->oo_owner.so_client->cl_lock); list_add(&stp->st_locks, &open_stp->st_locks); + list_add(&stp->st_perstateowner, &lo->lo_owner.so_stateids); spin_lock(&fp->fi_lock); list_add(&stp->st_perfile, &fp->fi_stateids); spin_unlock(&fp->fi_lock); + spin_unlock(&oo->oo_owner.so_client->cl_lock); return stp; }