Commit 1c755dc1 authored by Jeff Layton's avatar Jeff Layton Committed by J. Bruce Fields
Browse files

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: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: default avatarJeff Layton <jlayton@primarydata.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent b49e084d

fs/nfsd/nfs4state.c

+19 −2
Original line number Diff line number Diff line
@@ -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;

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE