nfsd: Make init_open_stateid() a bit more whole

Move the state selection logic inside from the caller,
always making it return correct stp to use.

Signed-off-by: J . Bruce Fields <bfields@fieldses.org>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 12 insertions, 15 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 94854a06c9ad..70d0b9b33031 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3480,13 +3480,14 @@ alloc_init_open_stateowner(unsigned int strhashval, struct nfsd4_open *open,
 }
 
 static struct nfs4_ol_stateid *
-init_open_stateid(struct nfs4_ol_stateid *stp, struct nfs4_file *fp,
-                struct nfsd4_open *open)
+init_open_stateid(struct nfs4_file *fp, struct nfsd4_open *open)
 {
 
         struct nfs4_openowner *oo = open->op_openowner;
         struct nfs4_ol_stateid *retstp = NULL;
+        struct nfs4_ol_stateid *stp;
 
+        stp = open->op_stp;
         /* We are moving these outside of the spinlocks to avoid the warnings */
         mutex_init(&stp->st_mutex);
         mutex_lock(&stp->st_mutex);
@@ -3497,6 +3498,8 @@ init_open_stateid(struct nfs4_ol_stateid *stp, struct nfs4_file *fp,
         retstp = nfsd4_find_existing_open(fp, open);
         if (retstp)
                 goto out_unlock;
+
+        open->op_stp = NULL;
         atomic_inc(&stp->st_stid.sc_count);
         stp->st_stid.sc_type = NFS4_OPEN_STID;
         INIT_LIST_HEAD(&stp->st_locks);
@@ -3514,10 +3517,11 @@ out_unlock:
         spin_unlock(&oo->oo_owner.so_client->cl_lock);
         if (retstp) {
                 mutex_lock(&retstp->st_mutex);
-                /* Not that we need to, just for neatness */
+                /* To keep mutex tracking happy */
                 mutex_unlock(&stp->st_mutex);
+                stp = retstp;
         }
-        return retstp;
+        return stp;
 }
 
 /*
@@ -4313,7 +4317,6 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf
         struct nfs4_client *cl = open->op_openowner->oo_owner.so_client;
         struct nfs4_file *fp = NULL;
         struct nfs4_ol_stateid *stp = NULL;
-        struct nfs4_ol_stateid *swapstp = NULL;
         struct nfs4_delegation *dp = NULL;
         __be32 status;
 
@@ -4350,16 +4353,10 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf
                         goto out;
                 }
         } else {
-                stp = open->op_stp;
-                open->op_stp = NULL;
-                /*
-                 * init_open_stateid() either returns a locked stateid
-                 * it found, or initializes and locks the new one we passed in
-                 */
-                swapstp = init_open_stateid(stp, fp, open);
-                if (swapstp) {
-                        nfs4_put_stid(&stp->st_stid);
-                        stp = swapstp;
+                /* stp is returned locked. */
+                stp = init_open_stateid(fp, open);
+                /* See if we lost the race to some other thread */
+                if (stp->st_access_bmap != 0) {
                         status = nfs4_upgrade_open(rqstp, fp, current_fh,
                                                 stp, open);
                         if (status) {