[v3,043/114] nfsd: Add locking to protect the state owner lists

Commit Message

Jeff Layton June 30, 2014, 3:49 p.m. UTC

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 <[e-mail]>
Signed-off-by: Jeff Layton <[e-mail]>
---
 fs/nfsd/nfs4state.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

Patch

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index aea256264266..05d0fac2e50a 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -863,6 +863,8 @@  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);
@@ -896,9 +898,13 @@  static void put_generic_stateid(struct nfs4_ol_stateid *stp)
 
 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);
 	put_generic_stateid(stp);
 }
 
@@ -942,20 +948,26 @@  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)
@@ -2965,7 +2977,6 @@  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;
@@ -2974,9 +2985,12 @@  static void init_open_stateid(struct nfs4_ol_stateid *stp, struct nfs4_file *fp,
 	set_access(open->op_share_access, stp);
 	set_deny(open->op_share_deny, stp);
 	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
@@ -4641,6 +4655,7 @@  alloc_init_lock_stateowner(unsigned int strhashval, struct nfs4_client *clp, str
 static struct nfs4_ol_stateid *
 alloc_init_lock_stateid(struct nfs4_lockowner *lo, struct nfs4_file *fp, struct nfs4_ol_stateid *open_stp)
 {
+	struct nfs4_openowner *oo = openowner(open_stp->st_stateowner);
 	struct nfs4_ol_stateid *stp;
 	struct nfs4_client *clp = lo->lo_owner.so_client;
 
@@ -4648,7 +4663,6 @@  alloc_init_lock_stateid(struct nfs4_lockowner *lo, struct nfs4_file *fp, struct
 	if (stp == NULL)
 		return NULL;
 	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;
@@ -4656,10 +4670,13 @@  alloc_init_lock_stateid(struct nfs4_lockowner *lo, struct nfs4_file *fp, struct
 	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;
 }