[PATCH] knfsd: remove nfsd_versbits as intermediate storage for desired versions

We have an array 'nfsd_version' which lists the available versions of nfsd,
and 'nfsd_versions' (poor choice there :-() which lists the currently active
versions.

Then we have a bitmap - nfsd_versbits which says which versions are wanted.
The bits in this bitset cause content to be copied from nfsd_version to
nfsd_versions when nfsd starts.

This patch removes nfsd_versbits and moves information directly from
nfsd_version to nfsd_versions when requests for version changes arrive.

Note that this doesn't make it possible to change versions while the server is
running.  This is because serv->sv_xdrsize is calculated when a service is
created, and used when threads are created, and xdrsize depends on the active
versions.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

4 files changed, 62 insertions, 70 deletions

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 7046ac9cf97f..d6881774ea57 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -35,8 +35,6 @@
 
 #include <asm/uaccess.h>
 
-unsigned int nfsd_versbits = ~0;
-
 /*
  *      We have a single directory with 9 nodes in it.
  */
@@ -372,6 +370,10 @@ static ssize_t write_versions(struct file *file, char *buf, size_t size)
 
         if (size>0) {
                 if (nfsd_serv)
+                        /* Cannot change versions without updating
+                         * nfsd_serv->sv_xdrsize, and reallocing
+                         * rq_argp and rq_resp
+                         */
                         return -EBUSY;
                 if (buf[size-1] != '\n')
                         return -EINVAL;
@@ -390,10 +392,7 @@ static ssize_t write_versions(struct file *file, char *buf, size_t size)
                         case 2:
                         case 3:
                         case 4:
-                                if (sign != '-')
-                                        NFSCTL_VERSET(nfsd_versbits, num);
-                                else
-                                        NFSCTL_VERUNSET(nfsd_versbits, num);
+                                nfsd_vers(num, sign == '-' ? NFSD_CLEAR : NFSD_SET);
                                 break;
                         default:
                                 return -EINVAL;
@@ -404,16 +403,15 @@ static ssize_t write_versions(struct file *file, char *buf, size_t size)
                 /* If all get turned off, turn them back on, as
                  * having no versions is BAD
                  */
-                if ((nfsd_versbits & NFSCTL_VERALL)==0)
-                        nfsd_versbits = NFSCTL_VERALL;
+                nfsd_reset_versions();
         }
         /* Now write current state into reply buffer */
         len = 0;
         sep = "";
         for (num=2 ; num <= 4 ; num++)
-                if (NFSCTL_VERISSET(NFSCTL_VERALL, num)) {
+                if (nfsd_vers(num, NFSD_AVAIL)) {
                         len += sprintf(buf+len, "%s%c%d", sep,
-                                       NFSCTL_VERISSET(nfsd_versbits, num)?'+':'-',
+                                       nfsd_vers(num, NFSD_TEST)?'+':'-',
                                        num);
                         sep = " ";
                 }
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 0339b4ddfa3b..140e3a2d1b9f 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -117,6 +117,32 @@ struct svc_program		nfsd_program = {
 
 };
 
+int nfsd_vers(int vers, enum vers_op change)
+{
+        if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
+                return -1;
+        switch(change) {
+        case NFSD_SET:
+                nfsd_versions[vers] = nfsd_version[vers];
+                break;
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+                if (vers < NFSD_ACL_NRVERS)
+                        nfsd_acl_version[vers] = nfsd_acl_version[vers];
+#endif
+        case NFSD_CLEAR:
+                nfsd_versions[vers] = NULL;
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+                if (vers < NFSD_ACL_NRVERS)
+                        nfsd_acl_version[vers] = NULL;
+#endif
+                break;
+        case NFSD_TEST:
+                return nfsd_versions[vers] != NULL;
+        case NFSD_AVAIL:
+                return nfsd_version[vers] != NULL;
+        }
+        return 0;
+}
 /*
  * Maximum number of nfsd processes
  */
@@ -147,16 +173,36 @@ static void nfsd_last_thread(struct svc_serv *serv)
                 nfsd_export_flush();
         }
 }
+
+void nfsd_reset_versions(void)
+{
+        int found_one = 0;
+        int i;
+
+        for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
+                if (nfsd_program.pg_vers[i])
+                        found_one = 1;
+        }
+
+        if (!found_one) {
+                for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++)
+                        nfsd_program.pg_vers[i] = nfsd_version[i];
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+                for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++)
+                        nfsd_acl_program.pg_vers[i] =
+                                nfsd_acl_version[i];
+#endif
+        }
+}
+
 int
 nfsd_svc(unsigned short port, int nrservs)
 {
         int     error;
-        int     found_one, i;
         struct list_head *victim;
         
         lock_kernel();
-        dprintk("nfsd: creating service: vers 0x%x\n",
-                nfsd_versbits);
+        dprintk("nfsd: creating service\n");
         error = -EINVAL;
         if (nrservs <= 0)
                 nrservs = 0;
@@ -171,46 +217,7 @@ nfsd_svc(unsigned short port, int nrservs)
         if (error<0)
                 goto out;
         if (!nfsd_serv) {
-                /*
-                 * Use the nfsd_ctlbits to define which
-                 * versions that will be advertised.
-                 * If nfsd_ctlbits doesn't list any version,
-                 * export them all.
-                 */
-                found_one = 0;
-
-                for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
-                        if (NFSCTL_VERISSET(nfsd_versbits, i)) {
-                                nfsd_program.pg_vers[i] = nfsd_version[i];
-                                found_one = 1;
-                        } else
-                                nfsd_program.pg_vers[i] = NULL;
-                }
-
-                if (!found_one) {
-                        for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++)
-                                nfsd_program.pg_vers[i] = nfsd_version[i];
-                }
-
-
-#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
-                found_one = 0;
-
-                for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) {
-                        if (NFSCTL_VERISSET(nfsd_versbits, i)) {
-                                nfsd_acl_program.pg_vers[i] =
-                                        nfsd_acl_version[i];
-                                found_one = 1;
-                        } else
-                                nfsd_acl_program.pg_vers[i] = NULL;
-                }
-
-                if (!found_one) {
-                        for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++)
-                                nfsd_acl_program.pg_vers[i] =
-                                        nfsd_acl_version[i];
-                }
-#endif
+                nfsd_reset_versions();
 
                 atomic_set(&nfsd_busy, 0);
                 error = -ENOMEM;
diff --git a/include/linux/nfsd/nfsd.h b/include/linux/nfsd/nfsd.h
index 2dcad295fece..46f1dc5b96dd 100644
--- a/include/linux/nfsd/nfsd.h
+++ b/include/linux/nfsd/nfsd.h
@@ -140,6 +140,10 @@ struct posix_acl *nfsd_get_posix_acl(struct svc_fh *, int);
 int nfsd_set_posix_acl(struct svc_fh *, int, struct posix_acl *);
 #endif
 
+enum vers_op {NFSD_SET, NFSD_CLEAR, NFSD_TEST, NFSD_AVAIL };
+int nfsd_vers(int vers, enum vers_op change);
+void nfsd_reset_versions(void);
+
 
 /* 
  * NFSv4 State
diff --git a/include/linux/nfsd/syscall.h b/include/linux/nfsd/syscall.h
index dae0faea2807..8bcddccb6c42 100644
--- a/include/linux/nfsd/syscall.h
+++ b/include/linux/nfsd/syscall.h
@@ -38,21 +38,6 @@
 #define NFSCTL_GETFD            7       /* get an fh by path (used by mountd) */
 #define NFSCTL_GETFS            8       /* get an fh by path with max FH len */
 
-/*
- * Macros used to set version
- */
-#define NFSCTL_VERSET(_cltbits, _v)   ((_cltbits) |=  (1 << (_v)))
-#define NFSCTL_VERUNSET(_cltbits, _v) ((_cltbits) &= ~(1 << (_v)))
-#define NFSCTL_VERISSET(_cltbits, _v) ((_cltbits) & (1 << (_v)))
-
-#if defined(CONFIG_NFSD_V4)
-#define NFSCTL_VERALL   (0x1c /* 0b011100 */)
-#elif defined(CONFIG_NFSD_V3)
-#define NFSCTL_VERALL   (0x0c /* 0b001100 */)
-#else
-#define NFSCTL_VERALL   (0x04 /* 0b000100 */)
-#endif
-
 /* SVC */
 struct nfsctl_svc {
         unsigned short          svc_port;
@@ -134,8 +119,6 @@ extern int		exp_delclient(struct nfsctl_client *ncp);
 extern int              exp_export(struct nfsctl_export *nxp);
 extern int              exp_unexport(struct nfsctl_export *nxp);
 
-extern unsigned int nfsd_versbits;
-
 #endif /* __KERNEL__ */
 
 #endif /* NFSD_SYSCALL_H */