NFSD: added FREE_STATEID operation

This operation is used by the client to tell the server to free a
stateid.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

4 files changed, 161 insertions, 2 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 7406f1cfd001..a27dea50273d 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1417,6 +1417,11 @@ static struct nfsd4_operation nfsd4_ops[] = {
                 .op_flags = OP_HANDLES_WRONGSEC,
                 .op_name = "OP_SECINFO_NO_NAME",
         },
+        [OP_FREE_STATEID] = {
+                .op_func = (nfsd4op_func)nfsd4_free_stateid,
+                .op_flags = ALLOWED_WITHOUT_FH,
+                .op_name = "OP_FREE_STATEID",
+        },
 };
 
 static const char *nfsd4_op_name(unsigned opnum)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index e98f3c2e9492..55c36e267b7d 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -60,9 +60,12 @@ static u64 current_sessionid = 1;
 
 /* forward declarations */
 static struct nfs4_stateid * find_stateid(stateid_t *stid, int flags);
+static struct nfs4_stateid * search_for_stateid(stateid_t *stid);
+static struct nfs4_delegation * search_for_delegation(stateid_t *stid);
 static struct nfs4_delegation * find_delegation_stateid(struct inode *ino, stateid_t *stid);
 static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
 static void nfs4_set_recdir(char *recdir);
+static int check_for_locks(struct nfs4_file *filp, struct nfs4_stateowner *lowner);
 
 /* Locking: */
 
@@ -3137,6 +3140,11 @@ static int is_delegation_stateid(stateid_t *stateid)
         return stateid->si_fileid == 0;
 }
 
+static int is_open_stateid(struct nfs4_stateid *stateid)
+{
+        return stateid->st_openstp == NULL;
+}
+
 /*
 * Checks for stateid operations
 */
@@ -3216,6 +3224,70 @@ out:
         return status;
 }
 
+static __be32
+nfsd4_free_delegation_stateid(stateid_t *stateid)
+{
+        struct nfs4_delegation *dp = search_for_delegation(stateid);
+        if (dp)
+                return nfserr_locks_held;
+        return nfserr_bad_stateid;
+}
+
+static __be32
+nfsd4_free_lock_stateid(struct nfs4_stateid *stp)
+{
+        if (check_for_locks(stp->st_file, stp->st_stateowner))
+                return nfserr_locks_held;
+        release_lock_stateid(stp);
+        return nfs_ok;
+}
+
+/*
+ * Free a state id
+ */
+__be32
+nfsd4_free_stateid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+                   struct nfsd4_free_stateid *free_stateid)
+{
+        stateid_t *stateid = &free_stateid->fr_stateid;
+        struct nfs4_stateid *stp;
+        __be32 ret;
+
+        nfs4_lock_state();
+        if (is_delegation_stateid(stateid)) {
+                ret = nfsd4_free_delegation_stateid(stateid);
+                goto out;
+        }
+
+        stp = search_for_stateid(stateid);
+        if (!stp) {
+                ret = nfserr_bad_stateid;
+                goto out;
+        }
+        if (stateid->si_generation != 0) {
+                if (stateid->si_generation < stp->st_stateid.si_generation) {
+                        ret = nfserr_old_stateid;
+                        goto out;
+                }
+                if (stateid->si_generation > stp->st_stateid.si_generation) {
+                        ret = nfserr_bad_stateid;
+                        goto out;
+                }
+        }
+
+        if (is_open_stateid(stp)) {
+                ret = nfserr_locks_held;
+                goto out;
+        } else {
+                ret = nfsd4_free_lock_stateid(stp);
+                goto out;
+        }
+
+out:
+        nfs4_unlock_state();
+        return ret;
+}
+
 static inline int
 setlkflg (int type)
 {
@@ -3594,6 +3666,14 @@ static struct list_head lock_ownerid_hashtbl[LOCK_HASH_SIZE];
 static struct list_head lock_ownerstr_hashtbl[LOCK_HASH_SIZE];
 static struct list_head lockstateid_hashtbl[STATEID_HASH_SIZE];
 
+static int
+same_stateid(stateid_t *id_one, stateid_t *id_two)
+{
+        if (id_one->si_stateownerid != id_two->si_stateownerid)
+                return 0;
+        return id_one->si_fileid == id_two->si_fileid;
+}
+
 static struct nfs4_stateid *
 find_stateid(stateid_t *stid, int flags)
 {
@@ -3623,6 +3703,44 @@ find_stateid(stateid_t *stid, int flags)
         return NULL;
 }
 
+static struct nfs4_stateid *
+search_for_stateid(stateid_t *stid)
+{
+        struct nfs4_stateid *local;
+        unsigned int hashval = stateid_hashval(stid->si_stateownerid, stid->si_fileid);
+
+        list_for_each_entry(local, &lockstateid_hashtbl[hashval], st_hash) {
+                if (same_stateid(&local->st_stateid, stid))
+                        return local;
+        }
+
+        list_for_each_entry(local, &stateid_hashtbl[hashval], st_hash) {
+                if (same_stateid(&local->st_stateid, stid))
+                        return local;
+        }
+        return NULL;
+}
+
+static struct nfs4_delegation *
+search_for_delegation(stateid_t *stid)
+{
+        struct nfs4_file *fp;
+        struct nfs4_delegation *dp;
+        struct list_head *pos;
+        int i;
+
+        for (i = 0; i < FILE_HASH_SIZE; i++) {
+                list_for_each_entry(fp, &file_hashtbl[i], fi_hash) {
+                        list_for_each(pos, &fp->fi_delegations) {
+                                dp = list_entry(pos, struct nfs4_delegation, dl_perfile);
+                                if (same_stateid(&dp->dl_stateid, stid))
+                                        return dp;
+                        }
+                }
+        }
+        return NULL;
+}
+
 static struct nfs4_delegation *
 find_delegation_stateid(struct inode *ino, stateid_t *stid)
 {
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 990181103214..ef9bd6f24fc0 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1246,6 +1246,19 @@ nfsd4_decode_destroy_session(struct nfsd4_compoundargs *argp,
 }
 
 static __be32
+nfsd4_decode_free_stateid(struct nfsd4_compoundargs *argp,
+                          struct nfsd4_free_stateid *free_stateid)
+{
+        DECODE_HEAD;
+
+        READ_BUF(sizeof(stateid_t));
+        READ32(free_stateid->fr_stateid.si_generation);
+        COPYMEM(&free_stateid->fr_stateid.si_opaque, sizeof(stateid_opaque_t));
+
+        DECODE_TAIL;
+}
+
+static __be32
 nfsd4_decode_sequence(struct nfsd4_compoundargs *argp,
                       struct nfsd4_sequence *seq)
 {
@@ -1370,7 +1383,7 @@ static nfsd4_dec nfsd41_dec_ops[] = {
         [OP_EXCHANGE_ID]        = (nfsd4_dec)nfsd4_decode_exchange_id,
         [OP_CREATE_SESSION]     = (nfsd4_dec)nfsd4_decode_create_session,
         [OP_DESTROY_SESSION]    = (nfsd4_dec)nfsd4_decode_destroy_session,
-        [OP_FREE_STATEID]       = (nfsd4_dec)nfsd4_decode_notsupp,
+        [OP_FREE_STATEID]       = (nfsd4_dec)nfsd4_decode_free_stateid,
         [OP_GET_DIR_DELEGATION] = (nfsd4_dec)nfsd4_decode_notsupp,
         [OP_GETDEVICEINFO]      = (nfsd4_dec)nfsd4_decode_notsupp,
         [OP_GETDEVICELIST]      = (nfsd4_dec)nfsd4_decode_notsupp,
@@ -3116,6 +3129,21 @@ nfsd4_encode_destroy_session(struct nfsd4_compoundres *resp, int nfserr,
 }
 
 static __be32
+nfsd4_encode_free_stateid(struct nfsd4_compoundres *resp, int nfserr,
+                          struct nfsd4_free_stateid *free_stateid)
+{
+        __be32 *p;
+
+        if (nfserr)
+                return nfserr;
+
+        RESERVE_SPACE(4);
+        WRITE32(nfserr);
+        ADJUST_ARGS();
+        return nfserr;
+}
+
+static __be32
 nfsd4_encode_sequence(struct nfsd4_compoundres *resp, int nfserr,
                       struct nfsd4_sequence *seq)
 {
@@ -3196,7 +3224,7 @@ static nfsd4_enc nfsd4_enc_ops[] = {
         [OP_EXCHANGE_ID]        = (nfsd4_enc)nfsd4_encode_exchange_id,
         [OP_CREATE_SESSION]     = (nfsd4_enc)nfsd4_encode_create_session,
         [OP_DESTROY_SESSION]    = (nfsd4_enc)nfsd4_encode_destroy_session,
-        [OP_FREE_STATEID]       = (nfsd4_enc)nfsd4_encode_noop,
+        [OP_FREE_STATEID]       = (nfsd4_enc)nfsd4_encode_free_stateid,
         [OP_GET_DIR_DELEGATION] = (nfsd4_enc)nfsd4_encode_noop,
         [OP_GETDEVICEINFO]      = (nfsd4_enc)nfsd4_encode_noop,
         [OP_GETDEVICELIST]      = (nfsd4_enc)nfsd4_encode_noop,
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 366401e1a536..ed1784d31a60 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -342,6 +342,11 @@ struct nfsd4_setclientid_confirm {
         nfs4_verifier   sc_confirm;
 };
 
+struct nfsd4_free_stateid {
+        stateid_t       fr_stateid;         /* request */
+        __be32          fr_status;          /* response */
+};
+
 /* also used for NVERIFY */
 struct nfsd4_verify {
         u32             ve_bmval[3];        /* request */
@@ -432,6 +437,7 @@ struct nfsd4_op {
                 struct nfsd4_destroy_session    destroy_session;
                 struct nfsd4_sequence           sequence;
                 struct nfsd4_reclaim_complete   reclaim_complete;
+                struct nfsd4_free_stateid       free_stateid;
         } u;
         struct nfs4_replay *                    replay;
 };
@@ -564,6 +570,8 @@ extern __be32 nfsd4_delegreturn(struct svc_rqst *rqstp,
                 struct nfsd4_compound_state *, struct nfsd4_delegreturn *dr);
 extern __be32 nfsd4_renew(struct svc_rqst *rqstp,
                           struct nfsd4_compound_state *, clientid_t *clid);
+extern __be32 nfsd4_free_stateid(struct svc_rqst *rqstp,
+                struct nfsd4_compound_state *, struct nfsd4_free_stateid *free_stateid);
 #endif
 
 /*