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

net/ceph/messenger.c

+31 −25
Original line number Diff line number Diff line
@@ -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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