nfsd: Do not let nfs4_file pin the struct inode

Remove the fi_inode field in struct nfs4_file in order to remove the
possibility of struct nfs4_file pinning the inode when it does not have
any open state.

The only place we still need to get to an inode is in check_for_locks,
so change it to use find_any_file and use the inode from any that it
finds. If it doesn't find one, then just assume there aren't any.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 28 insertions, 21 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 6ced8d566c0b..1dfc8ee85c93 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -70,7 +70,7 @@ static u64 current_sessionid = 1;
 #define CURRENT_STATEID(stateid) (!memcmp((stateid), &currentstateid, sizeof(stateid_t)))
 
 /* forward declarations */
-static int check_for_locks(struct nfs4_file *filp, struct nfs4_lockowner *lowner);
+static bool check_for_locks(struct nfs4_file *fp, struct nfs4_lockowner *lowner);
 
 /* Locking: */
 
@@ -259,7 +259,6 @@ put_nfs4_file(struct nfs4_file *fi)
         if (atomic_dec_and_lock(&fi->fi_ref, &state_lock)) {
                 hlist_del(&fi->fi_hash);
                 spin_unlock(&state_lock);
-                iput(fi->fi_inode);
                 nfsd4_free_file(fi);
         }
 }
@@ -2845,8 +2844,7 @@ static struct nfs4_file *nfsd4_alloc_file(void)
 }
 
 /* OPEN Share state helper functions */
-static void nfsd4_init_file(struct nfs4_file *fp, struct inode *ino,
-                struct knfsd_fh *fh)
+static void nfsd4_init_file(struct nfs4_file *fp, struct knfsd_fh *fh)
 {
         unsigned int hashval = file_hashval(fh);
 
@@ -2856,8 +2854,6 @@ static void nfsd4_init_file(struct nfs4_file *fp, struct inode *ino,
         spin_lock_init(&fp->fi_lock);
         INIT_LIST_HEAD(&fp->fi_stateids);
         INIT_LIST_HEAD(&fp->fi_delegations);
-        ihold(ino);
-        fp->fi_inode = ino;
         fh_copy_shallow(&fp->fi_fhandle, fh);
         fp->fi_had_conflict = false;
         fp->fi_lease = NULL;
@@ -3063,14 +3059,14 @@ find_file(struct knfsd_fh *fh)
 }
 
 static struct nfs4_file *
-find_or_add_file(struct inode *ino, struct nfs4_file *new, struct knfsd_fh *fh)
+find_or_add_file(struct nfs4_file *new, struct knfsd_fh *fh)
 {
         struct nfs4_file *fp;
 
         spin_lock(&state_lock);
         fp = find_file_locked(fh);
         if (fp == NULL) {
-                nfsd4_init_file(new, ino, fh);
+                nfsd4_init_file(new, fh);
                 fp = new;
         }
         spin_unlock(&state_lock);
@@ -3714,7 +3710,6 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf
         struct nfsd4_compoundres *resp = rqstp->rq_resp;
         struct nfs4_client *cl = open->op_openowner->oo_owner.so_client;
         struct nfs4_file *fp = NULL;
-        struct inode *ino = current_fh->fh_dentry->d_inode;
         struct nfs4_ol_stateid *stp = NULL;
         struct nfs4_delegation *dp = NULL;
         __be32 status;
@@ -3724,7 +3719,7 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf
          * and check for delegations in the process of being recalled.
          * If not found, create the nfs4_file struct
          */
-        fp = find_or_add_file(ino, open->op_file, &current_fh->fh_handle);
+        fp = find_or_add_file(open->op_file, &current_fh->fh_handle);
         if (fp != open->op_file) {
                 status = nfs4_check_deleg(cl, open, &dp);
                 if (status)
@@ -4663,7 +4658,9 @@ 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)
+alloc_init_lock_stateid(struct nfs4_lockowner *lo, struct nfs4_file *fp,
+                struct inode *inode,
+                struct nfs4_ol_stateid *open_stp)
 {
         struct nfs4_ol_stateid *stp;
         struct nfs4_client *clp = lo->lo_owner.so_client;
@@ -4723,6 +4720,7 @@ static __be32 lookup_or_create_lock_state(struct nfsd4_compound_state *cstate, s
         struct nfs4_file *fi = ost->st_file;
         struct nfs4_openowner *oo = openowner(ost->st_stateowner);
         struct nfs4_client *cl = oo->oo_owner.so_client;
+        struct inode *inode = cstate->current_fh.fh_dentry->d_inode;
         struct nfs4_lockowner *lo;
         unsigned int strhashval;
         struct nfsd_net *nn = net_generic(cl->net, nfsd_net_id);
@@ -4743,7 +4741,7 @@ static __be32 lookup_or_create_lock_state(struct nfsd4_compound_state *cstate, s
 
         *lst = find_lock_stateid(lo, fi);
         if (*lst == NULL) {
-                *lst = alloc_init_lock_stateid(lo, fi, ost);
+                *lst = alloc_init_lock_stateid(lo, fi, inode, ost);
                 if (*lst == NULL) {
                         release_lockowner_if_empty(lo);
                         return nfserr_jukebox;
@@ -5092,25 +5090,34 @@ out_nfserr:
 
 /*
  * returns
- *      1: locks held by lockowner
- *      0: no locks held by lockowner
+ *      true:  locks held by lockowner
+ *      false: no locks held by lockowner
  */
-static int
-check_for_locks(struct nfs4_file *filp, struct nfs4_lockowner *lowner)
+static bool
+check_for_locks(struct nfs4_file *fp, struct nfs4_lockowner *lowner)
 {
         struct file_lock **flpp;
-        struct inode *inode = filp->fi_inode;
-        int status = 0;
+        int status = false;
+        struct file *filp = find_any_file(fp);
+        struct inode *inode;
+
+        if (!filp) {
+                /* Any valid lock stateid should have some sort of access */
+                WARN_ON_ONCE(1);
+                return status;
+        }
+
+        inode = file_inode(filp);
 
         spin_lock(&inode->i_lock);
         for (flpp = &inode->i_flock; *flpp != NULL; flpp = &(*flpp)->fl_next) {
                 if ((*flpp)->fl_owner == (fl_owner_t)lowner) {
-                        status = 1;
-                        goto out;
+                        status = true;
+                        break;
                 }
         }
-out:
         spin_unlock(&inode->i_lock);
+        fput(filp);
         return status;
 }