3 files changed, 221 insertions, 123 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index b996a4badeb8..7ab572f9f388 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -162,6 +162,28 @@ static struct list_head	ownerstr_hashtbl[OWNER_HASH_SIZE];
 static struct list_head file_hashtbl[FILE_HASH_SIZE];
 static struct list_head stateid_hashtbl[STATEID_HASH_SIZE];
 
+static inline void nfs4_file_get_access(struct nfs4_file *fp, int oflag)
+{
+        BUG_ON(!(fp->fi_fds[oflag] || fp->fi_fds[O_RDWR]));
+        atomic_inc(&fp->fi_access[oflag]);
+}
+
+static inline void nfs4_file_put_fd(struct nfs4_file *fp, int oflag)
+{
+        if (fp->fi_fds[oflag]) {
+                fput(fp->fi_fds[oflag]);
+                fp->fi_fds[oflag] = NULL;
+        }
+}
+
+static inline void nfs4_file_put_access(struct nfs4_file *fp, int oflag)
+{
+        if (atomic_dec_and_test(&fp->fi_access[oflag])) {
+                nfs4_file_put_fd(fp, O_RDWR);
+                nfs4_file_put_fd(fp, oflag);
+        }
+}
+
 static struct nfs4_delegation *
 alloc_init_deleg(struct nfs4_client *clp, struct nfs4_stateid *stp, struct svc_fh *current_fh, u32 type)
 {
@@ -191,9 +213,8 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_stateid *stp, struct svc_f
         dp->dl_client = clp;
         get_nfs4_file(fp);
         dp->dl_file = fp;
+        nfs4_file_get_access(fp, O_RDONLY);
         dp->dl_flock = NULL;
-        get_file(stp->st_vfs_file);
-        dp->dl_vfs_file = stp->st_vfs_file;
         dp->dl_type = type;
         dp->dl_ident = cb->cb_ident;
         dp->dl_stateid.si_boot = boot_time;
@@ -228,15 +249,12 @@ nfs4_put_delegation(struct nfs4_delegation *dp)
 static void
 nfs4_close_delegation(struct nfs4_delegation *dp)
 {
-        struct file *filp = dp->dl_vfs_file;
+        struct file *filp = find_readable_file(dp->dl_file);
 
         dprintk("NFSD: close_delegation dp %p\n",dp);
-        dp->dl_vfs_file = NULL;
-        /* The following nfsd_close may not actually close the file,
-         * but we want to remove the lease in any case. */
         if (dp->dl_flock)
                 vfs_setlease(filp, F_UNLCK, &dp->dl_flock);
-        nfsd_close(filp);
+        nfs4_file_put_access(dp->dl_file, O_RDONLY);
 }
 
 /* Called under the state lock. */
@@ -308,8 +326,12 @@ static void free_generic_stateid(struct nfs4_stateid *stp)
 
 static void release_lock_stateid(struct nfs4_stateid *stp)
 {
+        struct file *file;
+
         unhash_generic_stateid(stp);
-        locks_remove_posix(stp->st_vfs_file, (fl_owner_t)stp->st_stateowner);
+        file = find_any_file(stp->st_file);
+        if (file)
+                locks_remove_posix(file, (fl_owner_t)stp->st_stateowner);
         free_generic_stateid(stp);
 }
 
@@ -347,11 +369,85 @@ release_stateid_lockowners(struct nfs4_stateid *open_stp)
         }
 }
 
+/*
+ * We store the NONE, READ, WRITE, and BOTH bits separately in the
+ * st_{access,deny}_bmap field of the stateid, in order to track not
+ * only what share bits are currently in force, but also what
+ * combinations of share bits previous opens have used.  This allows us
+ * to enforce the recommendation of rfc 3530 14.2.19 that the server
+ * return an error if the client attempt to downgrade to a combination
+ * of share bits not explicable by closing some of its previous opens.
+ *
+ * XXX: This enforcement is actually incomplete, since we don't keep
+ * track of access/deny bit combinations; so, e.g., we allow:
+ *
+ *      OPEN allow read, deny write
+ *      OPEN allow both, deny none
+ *      DOWNGRADE allow read, deny none
+ *
+ * which we should reject.
+ */
+static void
+set_access(unsigned int *access, unsigned long bmap) {
+        int i;
+
+        *access = 0;
+        for (i = 1; i < 4; i++) {
+                if (test_bit(i, &bmap))
+                        *access |= i;
+        }
+}
+
+static void
+set_deny(unsigned int *deny, unsigned long bmap) {
+        int i;
+
+        *deny = 0;
+        for (i = 0; i < 4; i++) {
+                if (test_bit(i, &bmap))
+                        *deny |= i ;
+        }
+}
+
+static int
+test_share(struct nfs4_stateid *stp, struct nfsd4_open *open) {
+        unsigned int access, deny;
+
+        set_access(&access, stp->st_access_bmap);
+        set_deny(&deny, stp->st_deny_bmap);
+        if ((access & open->op_share_deny) || (deny & open->op_share_access))
+                return 0;
+        return 1;
+}
+
+static int nfs4_access_to_omode(u32 access)
+{
+        switch (access) {
+        case NFS4_SHARE_ACCESS_READ:
+                return O_RDONLY;
+        case NFS4_SHARE_ACCESS_WRITE:
+                return O_WRONLY;
+        case NFS4_SHARE_ACCESS_BOTH:
+                return O_RDWR;
+        }
+        BUG();
+}
+
+static int nfs4_access_bmap_to_omode(struct nfs4_stateid *stp)
+{
+        unsigned int access;
+
+        set_access(&access, stp->st_access_bmap);
+        return nfs4_access_to_omode(access);
+}
+
 static void release_open_stateid(struct nfs4_stateid *stp)
 {
+        int oflag = nfs4_access_bmap_to_omode(stp);
+
         unhash_generic_stateid(stp);
         release_stateid_lockowners(stp);
-        nfsd_close(stp->st_vfs_file);
+        nfs4_file_put_access(stp->st_file, oflag);
         free_generic_stateid(stp);
 }
 
@@ -1763,6 +1859,8 @@ alloc_init_file(struct inode *ino)
                 fp->fi_inode = igrab(ino);
                 fp->fi_id = current_fileid++;
                 fp->fi_had_conflict = false;
+                memset(fp->fi_fds, 0, sizeof(fp->fi_fds));
+                memset(fp->fi_access, 0, sizeof(fp->fi_access));
                 spin_lock(&recall_lock);
                 list_add(&fp->fi_hash, &file_hashtbl[hashval]);
                 spin_unlock(&recall_lock);
@@ -1974,57 +2072,6 @@ static inline int deny_valid(u32 x)
 }
 
 /*
- * We store the NONE, READ, WRITE, and BOTH bits separately in the
- * st_{access,deny}_bmap field of the stateid, in order to track not
- * only what share bits are currently in force, but also what
- * combinations of share bits previous opens have used.  This allows us
- * to enforce the recommendation of rfc 3530 14.2.19 that the server
- * return an error if the client attempt to downgrade to a combination
- * of share bits not explicable by closing some of its previous opens.
- *
- * XXX: This enforcement is actually incomplete, since we don't keep
- * track of access/deny bit combinations; so, e.g., we allow:
- *
- *      OPEN allow read, deny write
- *      OPEN allow both, deny none
- *      DOWNGRADE allow read, deny none
- *
- * which we should reject.
- */
-static void
-set_access(unsigned int *access, unsigned long bmap) {
-        int i;
-
-        *access = 0;
-        for (i = 1; i < 4; i++) {
-                if (test_bit(i, &bmap))
-                        *access |= i;
-        }
-}
-
-static void
-set_deny(unsigned int *deny, unsigned long bmap) {
-        int i;
-
-        *deny = 0;
-        for (i = 0; i < 4; i++) {
-                if (test_bit(i, &bmap))
-                        *deny |= i ;
-        }
-}
-
-static int
-test_share(struct nfs4_stateid *stp, struct nfsd4_open *open) {
-        unsigned int access, deny;
-
-        set_access(&access, stp->st_access_bmap);
-        set_deny(&deny, stp->st_deny_bmap);
-        if ((access & open->op_share_deny) || (deny & open->op_share_access))
-                return 0;
-        return 1;
-}
-
-/*
  * Called to check deny when READ with all zero stateid or
  * WRITE with all zero or all one stateid
  */
@@ -2055,14 +2102,12 @@ out:
 }
 
 static inline void
-nfs4_file_downgrade(struct file *filp, unsigned int share_access)
+nfs4_file_downgrade(struct nfs4_file *fp, unsigned int share_access)
 {
-        if (share_access & NFS4_SHARE_ACCESS_WRITE) {
-                drop_file_write_access(filp);
-                spin_lock(&filp->f_lock);
-                filp->f_mode = (filp->f_mode | FMODE_READ) & ~FMODE_WRITE;
-                spin_unlock(&filp->f_lock);
-        }
+        if (share_access & NFS4_SHARE_ACCESS_WRITE)
+                nfs4_file_put_access(fp, O_WRONLY);
+        if (share_access & NFS4_SHARE_ACCESS_READ)
+                nfs4_file_put_access(fp, O_RDONLY);
 }
 
 /*
@@ -2328,32 +2373,42 @@ static inline int nfs4_access_to_access(u32 nfs4_access)
         return flags;
 }
 
+static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file
+*fp, struct svc_fh *cur_fh, u32 nfs4_access)
+{
+        __be32 status;
+        int oflag = nfs4_access_to_omode(nfs4_access);
+        int access = nfs4_access_to_access(nfs4_access);
+
+        if (!fp->fi_fds[oflag]) {
+                status = nfsd_open(rqstp, cur_fh, S_IFREG, access,
+                        &fp->fi_fds[oflag]);
+                if (status == nfserr_dropit)
+                        status = nfserr_jukebox;
+                if (status)
+                        return status;
+        }
+        nfs4_file_get_access(fp, oflag);
+
+        return nfs_ok;
+}
+
 static __be32
 nfs4_new_open(struct svc_rqst *rqstp, struct nfs4_stateid **stpp,
-                struct nfs4_delegation *dp,
-                struct svc_fh *cur_fh, struct nfsd4_open *open)
+                struct nfs4_file *fp, struct svc_fh *cur_fh,
+                struct nfsd4_open *open)
 {
         struct nfs4_stateid *stp;
+        __be32 status;
 
         stp = nfs4_alloc_stateid();
         if (stp == NULL)
                 return nfserr_resource;
 
-        if (dp) {
-                get_file(dp->dl_vfs_file);
-                stp->st_vfs_file = dp->dl_vfs_file;
-        } else {
-                __be32 status;
-                int access = nfs4_access_to_access(open->op_share_access);
-
-                status = nfsd_open(rqstp, cur_fh, S_IFREG, access,
-                                        &stp->st_vfs_file);
-                if (status) {
-                        if (status == nfserr_dropit)
-                                status = nfserr_jukebox;
-                        kmem_cache_free(stateid_slab, stp);
-                        return status;
-                }
+        status = nfs4_get_vfs_file(rqstp, fp, cur_fh, open->op_share_access);
+        if (status) {
+                kmem_cache_free(stateid_slab, stp);
+                return status;
         }
         *stpp = stp;
         return 0;
@@ -2375,36 +2430,29 @@ nfsd4_truncate(struct svc_rqst *rqstp, struct svc_fh *fh,
 }
 
 static __be32
-nfs4_upgrade_open(struct svc_rqst *rqstp, struct svc_fh *cur_fh, struct nfs4_stateid *stp, struct nfsd4_open *open)
+nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp, struct svc_fh *cur_fh, struct nfs4_stateid *stp, struct nfsd4_open *open)
 {
-        struct file *filp = stp->st_vfs_file;
-        struct inode *inode = filp->f_path.dentry->d_inode;
-        unsigned int share_access, new_writer;
-        u32 op_share_access;
+        u32 op_share_access, new_access;
         __be32 status;
 
-        set_access(&share_access, stp->st_access_bmap);
-        new_writer = (~share_access) & open->op_share_access
-                        & NFS4_SHARE_ACCESS_WRITE;
-
-        if (new_writer) {
-                int err = get_write_access(inode);
-                if (err)
-                        return nfserrno(err);
-                err = mnt_want_write(cur_fh->fh_export->ex_path.mnt);
-                if (err)
-                        return nfserrno(err);
-                file_take_write(filp);
+        set_access(&new_access, stp->st_access_bmap);
+        new_access = (~new_access) & open->op_share_access & ~NFS4_SHARE_WANT_MASK;
+
+        if (new_access) {
+                status = nfs4_get_vfs_file(rqstp, fp, cur_fh, new_access);
+                if (status)
+                        return status;
         }
         status = nfsd4_truncate(rqstp, cur_fh, open);
         if (status) {
-                if (new_writer)
-                        put_write_access(inode);
+                if (new_access) {
+                        int oflag = nfs4_access_to_omode(new_access);
+                        nfs4_file_put_access(fp, oflag);
+                }
                 return status;
         }
         /* remember the open */
         op_share_access = open->op_share_access & ~NFS4_SHARE_WANT_MASK;
-        filp->f_mode |= op_share_access;
         __set_bit(op_share_access, &stp->st_access_bmap);
         __set_bit(open->op_share_deny, &stp->st_deny_bmap);
 
@@ -2468,13 +2516,14 @@ nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open, struct nfs4_sta
         fl.fl_type = flag == NFS4_OPEN_DELEGATE_READ? F_RDLCK: F_WRLCK;
         fl.fl_end = OFFSET_MAX;
         fl.fl_owner =  (fl_owner_t)dp;
-        fl.fl_file = stp->st_vfs_file;
+        fl.fl_file = find_readable_file(stp->st_file);
+        BUG_ON(!fl.fl_file);
         fl.fl_pid = current->tgid;
 
         /* vfs_setlease checks to see if delegation should be handed out.
          * the lock_manager callbacks fl_mylease and fl_change are used
          */
-        if ((status = vfs_setlease(stp->st_vfs_file, fl.fl_type, &flp))) {
+        if ((status = vfs_setlease(fl.fl_file, fl.fl_type, &flp))) {
                 dprintk("NFSD: setlease failed [%d], no delegation\n", status);
                 unhash_delegation(dp);
                 flag = NFS4_OPEN_DELEGATE_NONE;
@@ -2538,13 +2587,12 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf
          */
         if (stp) {
                 /* Stateid was found, this is an OPEN upgrade */
-                status = nfs4_upgrade_open(rqstp, current_fh, stp, open);
+                status = nfs4_upgrade_open(rqstp, fp, current_fh, stp, open);
                 if (status)
                         goto out;
                 update_stateid(&stp->st_stateid);
         } else {
-                /* Stateid was not found, this is a new OPEN */
-                status = nfs4_new_open(rqstp, &stp, dp, current_fh, open);
+                status = nfs4_new_open(rqstp, &stp, fp, current_fh, open);
                 if (status)
                         goto out;
                 init_stateid(stp, fp, open);
@@ -2746,7 +2794,7 @@ search_close_lru(u32 st_id, int flags)
 static inline int
 nfs4_check_fh(struct svc_fh *fhp, struct nfs4_stateid *stp)
 {
-        return fhp->fh_dentry->d_inode != stp->st_vfs_file->f_path.dentry->d_inode;
+        return fhp->fh_dentry->d_inode != stp->st_file->fi_inode;
 }
 
 static int
@@ -2894,7 +2942,8 @@ nfs4_preprocess_stateid_op(struct nfsd4_compound_state *cstate,
                         goto out;
                 renew_client(dp->dl_client);
                 if (filpp)
-                        *filpp = dp->dl_vfs_file;
+                        *filpp = find_readable_file(dp->dl_file);
+                BUG_ON(!*filpp);
         } else { /* open or lock stateid */
                 stp = find_stateid(stateid, flags);
                 if (!stp)
@@ -2911,8 +2960,13 @@ nfs4_preprocess_stateid_op(struct nfsd4_compound_state *cstate,
                 if (status)
                         goto out;
                 renew_client(stp->st_stateowner->so_client);
-                if (filpp)
-                        *filpp = stp->st_vfs_file;
+                if (filpp) {
+                        if (flags & RD_STATE)
+                                *filpp = find_readable_file(stp->st_file);
+                        else
+                                *filpp = find_writeable_file(stp->st_file);
+                        BUG_ON(!*filpp); /* assured by check_openmode */
+                }
         }
         status = nfs_ok;
 out:
@@ -3148,8 +3202,7 @@ nfsd4_open_downgrade(struct svc_rqst *rqstp,
                 goto out;
         }
         set_access(&share_access, stp->st_access_bmap);
-        nfs4_file_downgrade(stp->st_vfs_file,
-                            share_access & ~od->od_share_access);
+        nfs4_file_downgrade(stp->st_file, share_access & ~od->od_share_access);
 
         reset_union_bmap_access(od->od_share_access, &stp->st_access_bmap);
         reset_union_bmap_deny(od->od_share_deny, &stp->st_deny_bmap);
@@ -3468,7 +3521,6 @@ alloc_init_lock_stateid(struct nfs4_stateowner *sop, struct nfs4_file *fp, struc
         stp->st_stateid.si_stateownerid = sop->so_id;
         stp->st_stateid.si_fileid = fp->fi_id;
         stp->st_stateid.si_generation = 0;
-        stp->st_vfs_file = open_stp->st_vfs_file; /* FIXME refcount?? */
         stp->st_deny_bmap = open_stp->st_deny_bmap;
         stp->st_openstp = open_stp;
 
@@ -3568,7 +3620,6 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                 lock_sop = lock->lk_replay_owner;
         }
         /* lock->lk_replay_owner and lock_stp have been created or found */
-        filp = lock_stp->st_vfs_file;
 
         status = nfserr_grace;
         if (locks_in_grace() && !lock->lk_reclaim)
@@ -3581,11 +3632,13 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         switch (lock->lk_type) {
                 case NFS4_READ_LT:
                 case NFS4_READW_LT:
+                        filp = find_readable_file(lock_stp->st_file);
                         file_lock.fl_type = F_RDLCK;
                         cmd = F_SETLK;
                 break;
                 case NFS4_WRITE_LT:
                 case NFS4_WRITEW_LT:
+                        filp = find_writeable_file(lock_stp->st_file);
                         file_lock.fl_type = F_WRLCK;
                         cmd = F_SETLK;
                 break;
@@ -3593,6 +3646,10 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                         status = nfserr_inval;
                 goto out;
         }
+        if (!filp) {
+                status = nfserr_openmode;
+                goto out;
+        }
         file_lock.fl_owner = (fl_owner_t)lock_sop;
         file_lock.fl_pid = current->tgid;
         file_lock.fl_file = filp;
@@ -3761,7 +3818,11 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                                         &locku->lu_stateowner, &stp, NULL)))
                 goto out;
 
-        filp = stp->st_vfs_file;
+        filp = find_any_file(stp->st_file);
+        if (!filp) {
+                status = nfserr_lock_range;
+                goto out;
+        }
         BUG_ON(!filp);
         locks_init_lock(&file_lock);
         file_lock.fl_type = F_UNLCK;
@@ -3808,10 +3869,10 @@ out_nfserr:
  *      0: no locks held by lockowner
  */
 static int
-check_for_locks(struct file *filp, struct nfs4_stateowner *lowner)
+check_for_locks(struct nfs4_file *filp, struct nfs4_stateowner *lowner)
 {
         struct file_lock **flpp;
-        struct inode *inode = filp->f_path.dentry->d_inode;
+        struct inode *inode = filp->fi_inode;
         int status = 0;
 
         lock_kernel();
@@ -3862,7 +3923,7 @@ nfsd4_release_lockowner(struct svc_rqst *rqstp,
                                 continue;
                         list_for_each_entry(stp, &sop->so_stateids,
                                         st_perstateowner) {
-                                if (check_for_locks(stp->st_vfs_file, sop))
+                                if (check_for_locks(stp->st_file, sop))
                                         goto out;
                                 /* Note: so_perclient unused for lockowners,
                                  * so it's OK to fool with here. */
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index 72377761270e..b76ac3a82e39 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -153,6 +153,7 @@ void		nfsd_lockd_shutdown(void);
 #define nfserr_bad_seqid        cpu_to_be32(NFSERR_BAD_SEQID)
 #define nfserr_symlink          cpu_to_be32(NFSERR_SYMLINK)
 #define nfserr_not_same         cpu_to_be32(NFSERR_NOT_SAME)
+#define nfserr_lock_range       cpu_to_be32(NFSERR_LOCK_RANGE)
 #define nfserr_restorefh        cpu_to_be32(NFSERR_RESTOREFH)
 #define nfserr_attrnotsupp      cpu_to_be32(NFSERR_ATTRNOTSUPP)
 #define nfserr_bad_xdr          cpu_to_be32(NFSERR_BAD_XDR)
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 006c84230c7c..7731a75971dd 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -88,7 +88,6 @@ struct nfs4_delegation {
         struct nfs4_client      *dl_client;
         struct nfs4_file        *dl_file;
         struct file_lock        *dl_flock;
-        struct file             *dl_vfs_file;
         u32                     dl_type;
         time_t                  dl_time;
 /* For recall: */
@@ -342,12 +341,50 @@ struct nfs4_file {
         struct list_head        fi_hash;    /* hash by "struct inode *" */
         struct list_head        fi_stateids;
         struct list_head        fi_delegations;
+        /* One each for O_RDONLY, O_WRONLY, O_RDWR: */
+        struct file *           fi_fds[3];
+        /* One each for O_RDONLY, O_WRONLY: */
+        atomic_t                fi_access[2];
+        /*
+         * Each open stateid contributes 1 to either fi_readers or
+         * fi_writers, or both, depending on the open mode.  A
+         * delegation also takes an fi_readers reference.  Lock
+         * stateid's take none.
+         */
+        atomic_t                fi_readers;
+        atomic_t                fi_writers;
         struct inode            *fi_inode;
         u32                     fi_id;      /* used with stateowner->so_id 
                                              * for stateid_hashtbl hash */
         bool                    fi_had_conflict;
 };
 
+/* XXX: for first cut may fall back on returning file that doesn't work
+ * at all? */
+static inline struct file *find_writeable_file(struct nfs4_file *f)
+{
+        if (f->fi_fds[O_RDWR])
+                return f->fi_fds[O_RDWR];
+        return f->fi_fds[O_WRONLY];
+}
+
+static inline struct file *find_readable_file(struct nfs4_file *f)
+{
+        if (f->fi_fds[O_RDWR])
+                return f->fi_fds[O_RDWR];
+        return f->fi_fds[O_RDONLY];
+}
+
+static inline struct file *find_any_file(struct nfs4_file *f)
+{
+        if (f->fi_fds[O_RDWR])
+                return f->fi_fds[O_RDWR];
+        else if (f->fi_fds[O_RDWR])
+                return f->fi_fds[O_WRONLY];
+        else
+                return f->fi_fds[O_RDONLY];
+}
+
 /*
 * nfs4_stateid can either be an open stateid or (eventually) a lock stateid
 *
@@ -373,7 +410,6 @@ struct nfs4_stateid {
         struct nfs4_stateowner      * st_stateowner;
         struct nfs4_file            * st_file;
         stateid_t                     st_stateid;
-        struct file                 * st_vfs_file;
         unsigned long                 st_access_bmap;
         unsigned long                 st_deny_bmap;
         struct nfs4_stateid         * st_openstp;