Commit 4740a623 authored by Sage Weil's avatar Sage Weil
Browse files

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: default avatarSage Weil <sage@inktank.com>
Reviewed-by: default avatarAlex Elder <elder@inktank.com>
parent 8636ea67
......@@ -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;
}
......
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