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authorSage Weil <sage@inktank.com>2012-07-30 18:19:30 -0700
committerSage Weil <sage@inktank.com>2012-07-30 18:19:30 -0700
commit4740a623d20c51d167da7f752b63e2b8714b2543 (patch)
tree25616d4073f56a2383fd155c457d97603d65b220 /net
parent8636ea672f0c5ab7478c42c5b6705ebd1db7eb6a (diff)
downloadlinux-4740a623d20c51d167da7f752b63e2b8714b2543.tar.gz
libceph: change ceph_con_in_msg_alloc convention to be less weird
This function's calling convention is very limiting. In particular, we can't return any error other than ENOMEM (and only implicitly), which is a problem (see next patch). Instead, return an normal 0 or error code, and make the skip a pointer output parameter. Drop the useless in_hdr argument (we have the con pointer). Signed-off-by: Sage Weil <sage@inktank.com> Reviewed-by: Alex Elder <elder@inktank.com>
Diffstat (limited to 'net')
-rw-r--r--net/ceph/messenger.c56
1 files changed, 31 insertions, 25 deletions
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index c3b628c7619..13b549b6b1b 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -1733,9 +1733,7 @@ static int read_partial_message_section(struct ceph_connection *con,
return 1;
}
-static bool ceph_con_in_msg_alloc(struct ceph_connection *con,
- struct ceph_msg_header *hdr);
-
+static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip);
static int read_partial_message_pages(struct ceph_connection *con,
struct page **pages,
@@ -1864,9 +1862,14 @@ static int read_partial_message(struct ceph_connection *con)
/* allocate message? */
if (!con->in_msg) {
+ int skip = 0;
+
dout("got hdr type %d front %d data %d\n", con->in_hdr.type,
con->in_hdr.front_len, con->in_hdr.data_len);
- if (ceph_con_in_msg_alloc(con, &con->in_hdr)) {
+ ret = ceph_con_in_msg_alloc(con, &skip);
+ if (ret < 0)
+ return ret;
+ if (skip) {
/* skip this message */
dout("alloc_msg said skip message\n");
BUG_ON(con->in_msg);
@@ -1876,12 +1879,8 @@ static int read_partial_message(struct ceph_connection *con)
con->in_seq++;
return 0;
}
- if (!con->in_msg) {
- con->error_msg =
- "error allocating memory for incoming message";
- return -ENOMEM;
- }
+ BUG_ON(!con->in_msg);
BUG_ON(con->in_msg->con != con);
m = con->in_msg;
m->front.iov_len = 0; /* haven't read it yet */
@@ -2715,43 +2714,50 @@ static int ceph_alloc_middle(struct ceph_connection *con, struct ceph_msg *msg)
* connection, and save the result in con->in_msg. Uses the
* connection's private alloc_msg op if available.
*
- * Returns true if the message should be skipped, false otherwise.
- * If true is returned (skip message), con->in_msg will be NULL.
- * If false is returned, con->in_msg will contain a pointer to the
- * newly-allocated message, or NULL in case of memory exhaustion.
+ * Returns 0 on success, or a negative error code.
+ *
+ * On success, if we set *skip = 1:
+ * - the next message should be skipped and ignored.
+ * - con->in_msg == NULL
+ * or if we set *skip = 0:
+ * - con->in_msg is non-null.
+ * On error (ENOMEM, EAGAIN, ...),
+ * - con->in_msg == NULL
*/
-static bool ceph_con_in_msg_alloc(struct ceph_connection *con,
- struct ceph_msg_header *hdr)
+static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip)
{
+ struct ceph_msg_header *hdr = &con->in_hdr;
int type = le16_to_cpu(hdr->type);
int front_len = le32_to_cpu(hdr->front_len);
int middle_len = le32_to_cpu(hdr->middle_len);
- int ret;
+ int ret = 0;
BUG_ON(con->in_msg != NULL);
if (con->ops->alloc_msg) {
- int skip = 0;
-
mutex_unlock(&con->mutex);
- con->in_msg = con->ops->alloc_msg(con, hdr, &skip);
+ con->in_msg = con->ops->alloc_msg(con, hdr, skip);
mutex_lock(&con->mutex);
if (con->in_msg) {
con->in_msg->con = con->ops->get(con);
BUG_ON(con->in_msg->con == NULL);
}
- if (skip)
+ if (*skip) {
con->in_msg = NULL;
-
- if (!con->in_msg)
- return skip != 0;
+ return 0;
+ }
+ if (!con->in_msg) {
+ con->error_msg =
+ "error allocating memory for incoming message";
+ return -ENOMEM;
+ }
}
if (!con->in_msg) {
con->in_msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
if (!con->in_msg) {
pr_err("unable to allocate msg type %d len %d\n",
type, front_len);
- return false;
+ return -ENOMEM;
}
con->in_msg->con = con->ops->get(con);
BUG_ON(con->in_msg->con == NULL);
@@ -2767,7 +2773,7 @@ static bool ceph_con_in_msg_alloc(struct ceph_connection *con,
}
}
- return false;
+ return ret;
}