Staging: Pohmelfs: Added IO permissions and priorities.

Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 66 insertions, 26 deletions

diff --git a/drivers/staging/pohmelfs/config.c b/drivers/staging/pohmelfs/config.c
index 3e67da9..a6eaa42 100644
--- a/drivers/staging/pohmelfs/config.c
+++ b/drivers/staging/pohmelfs/config.c
@@ -81,6 +81,45 @@ static struct pohmelfs_config_group *pohmelfs_find_create_config_group(unsigned
 	return g;
 }
 
+static inline void pohmelfs_insert_config_entry(struct pohmelfs_sb *psb, struct pohmelfs_config *dst)
+{
+	struct pohmelfs_config *tmp;
+
+	INIT_LIST_HEAD(&dst->config_entry);
+
+	list_for_each_entry(tmp, &psb->state_list, config_entry) {
+		if (dst->state.ctl.prio > tmp->state.ctl.prio)
+			list_add_tail(&dst->config_entry, &tmp->config_entry);
+	}
+	if (list_empty(&dst->config_entry))
+		list_add_tail(&dst->config_entry, &psb->state_list);
+}
+
+static int pohmelfs_move_config_entry(struct pohmelfs_sb *psb,
+		struct pohmelfs_config *dst, struct pohmelfs_config *new)
+{
+	if ((dst->state.ctl.prio == new->state.ctl.prio) &&
+		(dst->state.ctl.perm == new->state.ctl.perm))
+		return 0;
+
+	dprintk("%s: dst: prio: %d, perm: %x, new: prio: %d, perm: %d.\n",
+			__func__, dst->state.ctl.prio, dst->state.ctl.perm,
+			new->state.ctl.prio, new->state.ctl.perm);
+	dst->state.ctl.prio = new->state.ctl.prio;
+	dst->state.ctl.perm = new->state.ctl.perm;
+
+	list_del_init(&dst->config_entry);
+	pohmelfs_insert_config_entry(psb, dst);
+	return 0;
+}
+
+/*
+ * pohmelfs_copy_config() is used to copy new state configs from the
+ * config group (controlled by the netlink messages) into the superblock.
+ * This happens either at startup time where no transactions can access
+ * the list of the configs (and thus list of the network states), or at
+ * run-time, where it is protected by the psb->state_lock.
+ */
 int pohmelfs_copy_config(struct pohmelfs_sb *psb)
 {
 	struct pohmelfs_config_group *g;
@@ -103,7 +142,9 @@ int pohmelfs_copy_config(struct pohmelfs_sb *psb)
 		err = 0;
 		list_for_each_entry(dst, &psb->state_list, config_entry) {
 			if (pohmelfs_config_eql(&dst->state.ctl, &c->state.ctl)) {
-				err = -EEXIST;
+				err = pohmelfs_move_config_entry(psb, dst, c);
+				if (!err)
+					err = -EEXIST;
 				break;
 			}
 		}
@@ -119,7 +160,7 @@ int pohmelfs_copy_config(struct pohmelfs_sb *psb)
 
 		memcpy(&dst->state.ctl, &c->state.ctl, sizeof(struct pohmelfs_ctl));
 
-		list_add_tail(&dst->config_entry, &psb->state_list);
+		pohmelfs_insert_config_entry(psb, dst);
 
 		err = pohmelfs_state_init_one(psb, dst);
 		if (err) {
@@ -248,6 +289,13 @@ out_unlock:
         return err;
 }
 
+static int pohmelfs_modify_config(struct pohmelfs_ctl *old, struct pohmelfs_ctl *new)
+{
+	old->perm = new->perm;
+	old->prio = new->prio;
+	return 0;
+}
+
 static int pohmelfs_cn_ctl(struct cn_msg *msg, int action)
 {
 	struct pohmelfs_config_group *g;
@@ -278,6 +326,9 @@ static int pohmelfs_cn_ctl(struct cn_msg *msg, int action)
 				g->num_entry--;
 				kfree(c);
 				goto out_unlock;
+			} else if (action == POHMELFS_FLAGS_MODIFY) {
+				err = pohmelfs_modify_config(sc, ctl);
+				goto out_unlock;
 			} else {
 				err = -EEXIST;
 				goto out_unlock;
@@ -296,6 +347,7 @@ static int pohmelfs_cn_ctl(struct cn_msg *msg, int action)
 	}
 	memcpy(&c->state.ctl, ctl, sizeof(struct pohmelfs_ctl));
 	g->num_entry++;
+
 	list_add_tail(&c->config_entry, &g->config_list);
 
 out_unlock:
@@ -401,10 +453,9 @@ static void pohmelfs_cn_callback(void *data)
 
 	switch (msg->flags) {
 		case POHMELFS_FLAGS_ADD:
-			err = pohmelfs_cn_ctl(msg, POHMELFS_FLAGS_ADD);
-			break;
 		case POHMELFS_FLAGS_DEL:
-			err = pohmelfs_cn_ctl(msg, POHMELFS_FLAGS_DEL);
+		case POHMELFS_FLAGS_MODIFY:
+			err = pohmelfs_cn_ctl(msg, msg->flags);
 			break;
 		case POHMELFS_FLAGS_SHOW:
 			err = pohmelfs_cn_disp(msg);
diff --git a/drivers/staging/pohmelfs/netfs.h b/drivers/staging/pohmelfs/netfs.h
index 7700e2b..c78cfcb 100644
--- a/drivers/staging/pohmelfs/netfs.h
+++ b/drivers/staging/pohmelfs/netfs.h
@@ -87,6 +87,7 @@ enum {
 	POHMELFS_FLAGS_DEL,     /* Network state control message for DEL */
 	POHMELFS_FLAGS_SHOW,    /* Network state control message for SHOW */
 	POHMELFS_FLAGS_CRYPTO,	/* Crypto data control message */
+	POHMELFS_FLAGS_MODIFY,	/* Network state modification message */
 };
 
 /*
diff --git a/drivers/staging/pohmelfs/trans.c b/drivers/staging/pohmelfs/trans.c
index b89f9f3..168fc89 100644
--- a/drivers/staging/pohmelfs/trans.c
+++ b/drivers/staging/pohmelfs/trans.c
@@ -456,34 +456,22 @@ int netfs_trans_finish_send(struct netfs_trans *t, struct pohmelfs_sb *psb)
 		__func__, t, t->gen, t->iovec.iov_len, t->page_num, psb->active_state);
 #endif
 	mutex_lock(&psb->state_lock);
-
-	if ((t->flags & NETFS_TRANS_SINGLE_DST) && psb->active_state) {
-		st = &psb->active_state->state;
-
-		err = -EPIPE;
-		if (netfs_state_poll(st) & POLLOUT) {
-			err = netfs_trans_push_dst(t, st);
-			if (!err) {
-				err = netfs_trans_send(t, st);
-				if (err) {
-					netfs_trans_drop_last(t, st);
-				} else {
-					pohmelfs_switch_active(psb);
-					goto out;
-				}
-			}
-		}
-		pohmelfs_switch_active(psb);
-	}
-
 	list_for_each_entry(c, &psb->state_list, config_entry) {
 		st = &c->state;
 
+		if (t->flags & NETFS_TRANS_SINGLE_DST) {
+			if (!(st->ctl.perm & POHMELFS_IO_PERM_READ))
+				continue;
+		} else {
+			if (!(st->ctl.perm & POHMELFS_IO_PERM_WRITE))
+				continue;
+		}
+
 		err = netfs_trans_push(t, st);
 		if (!err && (t->flags & NETFS_TRANS_SINGLE_DST))
 			break;
 	}
-out:
+
 	mutex_unlock(&psb->state_lock);
 #if 0
 	dprintk("%s: fully sent t: %p, gen: %u, size: %u, page_num: %u, err: %d.\n",