diff mbox

[2/3] libceph: define mds_alloc_msg() method

Message ID 5134E401.6070604@inktank.com (mailing list archive)
State New, archived
Headers show

Commit Message

Alex Elder March 4, 2013, 6:12 p.m. UTC
The only user of the ceph messenger that doesn't define an alloc_msg
method is the mds client.  Define one, such that it works just like
it did before, and simplify ceph_con_in_msg_alloc() by assuming the
alloc_msg method is always present.

This and the next patch resolve:
    http://tracker.ceph.com/issues/4322

Signed-off-by: Alex Elder <elder@inktank.com>
---
 fs/ceph/mds_client.c |   23 ++++++++++++++++++++
 net/ceph/messenger.c |   59
++++++++++++++++----------------------------------
 2 files changed, 42 insertions(+), 40 deletions(-)

Comments

Gregory Farnum March 4, 2013, 7:05 p.m. UTC | #1
This looks like a faithful reshuffling to me.

But...
On Mon, Mar 4, 2013 at 10:12 AM, Alex Elder <elder@inktank.com> wrote:
> diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
> index 6ec6051..c7d4278 100644
> --- a/net/ceph/messenger.c
> +++ b/net/ceph/messenger.c
> @@ -2804,55 +2804,34 @@ static int ceph_alloc_middle(struct
> ceph_connection *con, struct ceph_msg *msg)
>  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);
>         struct ceph_msg *msg;
>         int ret = 0;
>
>         BUG_ON(con->in_msg != NULL);
> +       BUG_ON(!con->ops->alloc_msg);
>
> -       if (con->ops->alloc_msg) {
> -               mutex_unlock(&con->mutex);
> -               msg = con->ops->alloc_msg(con, hdr, skip);
> -               mutex_lock(&con->mutex);
> -               if (con->state != CON_STATE_OPEN) {
> -                       if (msg)
> -                               ceph_msg_put(msg);
> -                       return -EAGAIN;
> -               }
> -               con->in_msg = msg;
> -               if (con->in_msg) {
> -                       con->in_msg->con = con->ops->get(con);
> -                       BUG_ON(con->in_msg->con == NULL);
> -               }
> -               if (*skip) {
> -                       con->in_msg = NULL;
> -                       return 0;
> -               }
> -               if (!con->in_msg) {
> -                       con->error_msg =
> -                               "error allocating memory for incoming message";
> -                       return -ENOMEM;
> -               }
> -       }
> -       if (!con->in_msg) {
> -               mutex_unlock(&con->mutex);
> -               msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
> -               mutex_lock(&con->mutex);
> -               if (!msg) {
> -                       pr_err("unable to allocate msg type %d len %d\n",
> -                              type, front_len);
> -                       return -ENOMEM;
> -               }
> -               if (con->state != CON_STATE_OPEN) {
> +       mutex_unlock(&con->mutex);
> +       msg = con->ops->alloc_msg(con, hdr, skip);
> +       mutex_lock(&con->mutex);
> +       if (con->state != CON_STATE_OPEN) {
> +               if (msg)
>                         ceph_msg_put(msg);
> -                       return -EAGAIN;
> -               }
> -               con->in_msg = msg;
> +               return -EAGAIN;
> +       }
> +       con->in_msg = msg;
> +       if (con->in_msg) {
>                 con->in_msg->con = con->ops->get(con);
>                 BUG_ON(con->in_msg->con == NULL);
> -               con->in_msg->page_alignment = le16_to_cpu(hdr->data_off);
> +       }
> +       if (*skip) {
> +               con->in_msg = NULL;
> +               return 0;

This looks like a memory leak to me? I'm not familiar with the skip
infrastructure; is there something that cleans up those messages in
the background, or should this actually be a BUG_ON?
-Greg
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Alex Elder March 4, 2013, 7:37 p.m. UTC | #2
On 03/04/2013 01:05 PM, Gregory Farnum wrote:
> This looks like a faithful reshuffling to me.
> 
> But...
> On Mon, Mar 4, 2013 at 10:12 AM, Alex Elder <elder@inktank.com> wrote:
>> diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
>> index 6ec6051..c7d4278 100644
>> --- a/net/ceph/messenger.c
>> +++ b/net/ceph/messenger.c
>> @@ -2804,55 +2804,34 @@ static int ceph_alloc_middle(struct
>> ceph_connection *con, struct ceph_msg *msg)
>>  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);
>>         struct ceph_msg *msg;
>>         int ret = 0;
>>
>>         BUG_ON(con->in_msg != NULL);
>> +       BUG_ON(!con->ops->alloc_msg);
>>
>> -       if (con->ops->alloc_msg) {
>> -               mutex_unlock(&con->mutex);
>> -               msg = con->ops->alloc_msg(con, hdr, skip);
>> -               mutex_lock(&con->mutex);
>> -               if (con->state != CON_STATE_OPEN) {
>> -                       if (msg)
>> -                               ceph_msg_put(msg);
>> -                       return -EAGAIN;
>> -               }
>> -               con->in_msg = msg;
>> -               if (con->in_msg) {
>> -                       con->in_msg->con = con->ops->get(con);
>> -                       BUG_ON(con->in_msg->con == NULL);
>> -               }
>> -               if (*skip) {
>> -                       con->in_msg = NULL;
>> -                       return 0;
>> -               }
>> -               if (!con->in_msg) {
>> -                       con->error_msg =
>> -                               "error allocating memory for incoming message";
>> -                       return -ENOMEM;
>> -               }
>> -       }
>> -       if (!con->in_msg) {
>> -               mutex_unlock(&con->mutex);
>> -               msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
>> -               mutex_lock(&con->mutex);
>> -               if (!msg) {
>> -                       pr_err("unable to allocate msg type %d len %d\n",
>> -                              type, front_len);
>> -                       return -ENOMEM;
>> -               }
>> -               if (con->state != CON_STATE_OPEN) {
>> +       mutex_unlock(&con->mutex);
>> +       msg = con->ops->alloc_msg(con, hdr, skip);
>> +       mutex_lock(&con->mutex);
>> +       if (con->state != CON_STATE_OPEN) {
>> +               if (msg)
>>                         ceph_msg_put(msg);
>> -                       return -EAGAIN;
>> -               }
>> -               con->in_msg = msg;
>> +               return -EAGAIN;
>> +       }
>> +       con->in_msg = msg;
>> +       if (con->in_msg) {
>>                 con->in_msg->con = con->ops->get(con);
>>                 BUG_ON(con->in_msg->con == NULL);
>> -               con->in_msg->page_alignment = le16_to_cpu(hdr->data_off);
>> +       }
>> +       if (*skip) {
>> +               con->in_msg = NULL;
>> +               return 0;
> 
> This looks like a memory leak to me? I'm not familiar with the skip
> infrastructure; is there something that cleans up those messages in
> the background, or should this actually be a BUG_ON?

It looks that way to me too, but the con->ops->get(con) call before
it makes it a little tricky.  I will investigate and get back
to you, and if it is a leak I'll insert a fix for it ahead of this
in the series.

I really appreciate your reviewing these.

					-Alex

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diff mbox

Patch

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 76b7344..a4b986a 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -3469,6 +3469,28 @@  static int invalidate_authorizer(struct
ceph_connection *con)
 	return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
 }

+static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
+				struct ceph_msg_header *hdr, int *skip)
+{
+	struct ceph_msg *msg;
+	int type = (int) le16_to_cpu(hdr->type);
+	int front_len = (int) le32_to_cpu(hdr->front_len);
+
+	if (con->in_msg)
+		return con->in_msg;
+
+	*skip = 0;
+	msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
+	if (!msg) {
+		pr_err("unable to allocate msg type %d len %d\n",
+		       type, front_len);
+		return NULL;
+	}
+	msg->page_alignment = (unsigned int) le16_to_cpu(hdr->data_off);
+
+	return msg;
+}
+
 static const struct ceph_connection_operations mds_con_ops = {
 	.get = con_get,
 	.put = con_put,
@@ -3477,6 +3499,7 @@  static const struct ceph_connection_operations
mds_con_ops = {
 	.verify_authorizer_reply = verify_authorizer_reply,
 	.invalidate_authorizer = invalidate_authorizer,
 	.peer_reset = peer_reset,
+	.alloc_msg = mds_alloc_msg,
 };

 /* eof */
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 6ec6051..c7d4278 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -2804,55 +2804,34 @@  static int ceph_alloc_middle(struct
ceph_connection *con, struct ceph_msg *msg)
 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);
 	struct ceph_msg *msg;
 	int ret = 0;

 	BUG_ON(con->in_msg != NULL);
+	BUG_ON(!con->ops->alloc_msg);

-	if (con->ops->alloc_msg) {
-		mutex_unlock(&con->mutex);
-		msg = con->ops->alloc_msg(con, hdr, skip);
-		mutex_lock(&con->mutex);
-		if (con->state != CON_STATE_OPEN) {
-			if (msg)
-				ceph_msg_put(msg);
-			return -EAGAIN;
-		}
-		con->in_msg = msg;
-		if (con->in_msg) {
-			con->in_msg->con = con->ops->get(con);
-			BUG_ON(con->in_msg->con == NULL);
-		}
-		if (*skip) {
-			con->in_msg = NULL;
-			return 0;
-		}
-		if (!con->in_msg) {
-			con->error_msg =
-				"error allocating memory for incoming message";
-			return -ENOMEM;
-		}
-	}
-	if (!con->in_msg) {
-		mutex_unlock(&con->mutex);
-		msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
-		mutex_lock(&con->mutex);
-		if (!msg) {
-			pr_err("unable to allocate msg type %d len %d\n",
-			       type, front_len);
-			return -ENOMEM;
-		}
-		if (con->state != CON_STATE_OPEN) {
+	mutex_unlock(&con->mutex);
+	msg = con->ops->alloc_msg(con, hdr, skip);
+	mutex_lock(&con->mutex);
+	if (con->state != CON_STATE_OPEN) {
+		if (msg)
 			ceph_msg_put(msg);
-			return -EAGAIN;
-		}
-		con->in_msg = msg;
+		return -EAGAIN;
+	}
+	con->in_msg = msg;
+	if (con->in_msg) {
 		con->in_msg->con = con->ops->get(con);
 		BUG_ON(con->in_msg->con == NULL);
-		con->in_msg->page_alignment = le16_to_cpu(hdr->data_off);
+	}
+	if (*skip) {
+		con->in_msg = NULL;
+		return 0;
+	}
+	if (!con->in_msg) {
+		con->error_msg =
+			"error allocating memory for incoming message";
+		return -ENOMEM;
 	}
 	memcpy(&con->in_msg->hdr, &con->in_hdr, sizeof(con->in_hdr));