xenstore: Small cleanups and fixes.

 1. readfd/writefd account for EINTR/EAGAIN errno returns.
 2. Handle zero return from ->read() and ->write() handlers
    symmetrically.
 3. Fix some indentation issues (use hard tabs).
Signed-off-by: Keir Fraser <keir@xensource.com>

3 files changed, 35 insertions, 13 deletions

diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
index f62de82b77..1081103459 100644
--- a/tools/xenstore/xenstored_core.c
+++ b/tools/xenstore/xenstored_core.c
@@ -1266,7 +1266,7 @@ static void handle_input(struct connection *conn)
 	if (in->inhdr) {
 		bytes = conn->read(conn, in->hdr.raw + in->used,
 				   sizeof(in->hdr) - in->used);
-		if (bytes <= 0)
+		if (bytes < 0)
 			goto bad_client;
 		in->used += bytes;
 		if (in->used != sizeof(in->hdr))
@@ -1288,7 +1288,7 @@ static void handle_input(struct connection *conn)
 
 	bytes = conn->read(conn, in->buffer + in->used,
 			   in->hdr.msg.len - in->used);
-	if (bytes <= 0)
+	if (bytes < 0)
 		goto bad_client;
 
 	in->used += bytes;
@@ -1341,12 +1341,34 @@ struct connection *new_connection(connwritefn_t *write, connreadfn_t *read)
 
 static int writefd(struct connection *conn, const void *data, unsigned int len)
 {
-	return write(conn->fd, data, len);
+	int rc;
+
+	while ((rc = write(conn->fd, data, len)) < 0) {
+		if (errno == EAGAIN) {
+			rc = 0;
+			break;
+		}
+		if (errno != EINTR)
+			break;
+	}
+
+	return rc;
 }
 
 static int readfd(struct connection *conn, void *data, unsigned int len)
 {
-	return read(conn->fd, data, len);
+	int rc;
+
+	while ((rc = read(conn->fd, data, len)) < 0) {
+		if (errno == EAGAIN) {
+			rc = 0;
+			break;
+		}
+		if (errno != EINTR)
+			break;
+	}
+
+	return rc;
 }
 
 static void accept_connection(int sock, bool canwrite)
@@ -1439,13 +1461,13 @@ static void setup_structure(void)
 static unsigned int hash_from_key_fn(void *k)
 {
 	char *str = k;
-        unsigned int hash = 5381;
-        char c;
+	unsigned int hash = 5381;
+	char c;
 
-        while ((c = *str++))
+	while ((c = *str++))
 		hash = ((hash << 5) + hash) + (unsigned int)c;
 
-        return hash;
+	return hash;
 }
 
 
diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c
index c51e2c73b9..d166c0556e 100644
--- a/tools/xenstore/xenstored_domain.c
+++ b/tools/xenstore/xenstored_domain.c
@@ -76,7 +76,6 @@ struct domain
 
 static LIST_HEAD(domains);
 
-/* FIXME: Mark connection as broken (close it?) when this happens. */
 static bool check_indexes(XENSTORE_RING_IDX cons, XENSTORE_RING_IDX prod)
 {
 	return ((prod - cons) <= XENSTORE_RING_SIZE);
@@ -102,7 +101,8 @@ static const void *get_input_chunk(XENSTORE_RING_IDX cons,
 	return buf + MASK_XENSTORE_IDX(cons);
 }
 
-static int writechn(struct connection *conn, const void *data, unsigned int len)
+static int writechn(struct connection *conn,
+		    const void *data, unsigned int len)
 {
 	uint32_t avail;
 	void *dest;
@@ -113,6 +113,7 @@ static int writechn(struct connection *conn, const void *data, unsigned int len)
 	cons = intf->rsp_cons;
 	prod = intf->rsp_prod;
 	mb();
+
 	if (!check_indexes(cons, prod)) {
 		errno = EIO;
 		return -1;
diff --git a/tools/xenstore/xenstored_watch.c b/tools/xenstore/xenstored_watch.c
index 27e082a24f..f5692f83e5 100644
--- a/tools/xenstore/xenstored_watch.c
+++ b/tools/xenstore/xenstored_watch.c
@@ -73,11 +73,10 @@ static void add_event(struct connection *conn,
 	data = talloc_array(watch, char, len);
 	strcpy(data, name);
 	strcpy(data + strlen(name) + 1, watch->token);
-        send_reply(conn, XS_WATCH_EVENT, data, len);
+	send_reply(conn, XS_WATCH_EVENT, data, len);
 	talloc_free(data);
 }
 
-/* FIXME: we fail to fire on out of memory.  Should drop connections. */
 void fire_watches(struct connection *conn, const char *name, bool recurse)
 {
 	struct connection *i;
@@ -130,7 +129,7 @@ void do_watch(struct connection *conn, struct buffered_data *in)
 	/* Check for duplicates. */
 	list_for_each_entry(watch, &conn->watches, list) {
 		if (streq(watch->node, vec[0]) &&
-                    streq(watch->token, vec[1])) {
+		    streq(watch->token, vec[1])) {
 			send_error(conn, EEXIST);
 			return;
 		}