Patch "sunrpc: don't call sleeping functions from the notifier block callbacks" has been added to the 4.9-stable tree

PATCH [email protected] 1 participant 1 message Jan 23, 2017

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2017-01-23 14:20 UTC #0 lore raw

This is a note to let you know that I've just added the patch titled

sunrpc: don't call sleeping functions from the notifier block callbacks

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
sunrpc-don-t-call-sleeping-functions-from-the-notifier-block-callbacks.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 546125d1614264d26080817d0c8cddb9b25081fa Mon Sep 17 00:00:00 2001

From: Scott Mayhew <[email protected]>
Date: Thu, 5 Jan 2017 16:34:51 -0500
Subject: sunrpc: don't call sleeping functions from the notifier block callbacks

From: Scott Mayhew <[email protected]>

commit 546125d1614264d26080817d0c8cddb9b25081fa upstream.

The inet6addr_chain is an atomic notifier chain, so we can't call anything that might sleep (like lock_sock)... instead of closing the socket from svc_age_temp_xprts_now (which is called by the notifier function), just have the rpc service threads do it instead.

Fixes c3d4879e01be "sunrpc: Add a function to close..."

Signed-off-by Scott Mayhew <[email protected]>

Signed-off-by J. Bruce Fields <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

---
 include/linux/sunrpc/svc_xprt.h |    1 +
 net/sunrpc/svc_xprt.c           |   10 +++++++---
 2 files changed, 8 insertions(+), 3 deletions(-)

include/linux/sunrpc/svc_xprt.h +1 -0

@@ -66,6 +66,7 @@ struct svc_xprt {
 #define XPT_LISTENER	10		/* listening endpoint */
 #define XPT_CACHE_AUTH	11		/* cache auth info */
 #define XPT_LOCAL	12		/* connection from loopback interface */
+#define XPT_KILL_TEMP   13		/* call xpo_kill_temp_xprt before closing */
 
 	struct svc_serv		*xpt_server;	/* service for transport */
 	atomic_t    	    	xpt_reserved;	/* space on outq that is rsvd */

net/sunrpc/svc_xprt.c +7 -3

@@ -799,6 +799,8 @@ static int svc_handle_xprt(struct svc_rq
 
 	if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) {
 		dprintk("svc_recv: found XPT_CLOSE\n");
+		if (test_and_clear_bit(XPT_KILL_TEMP, &xprt->xpt_flags))
+			xprt->xpt_ops->xpo_kill_temp_xprt(xprt);
 		svc_delete_xprt(xprt);
 		/* Leave XPT_BUSY set on the dead xprt: */
 		goto out;

@@ -1020,9 +1022,11 @@ void svc_age_temp_xprts_now(struct svc_s
 		le = to_be_closed.next;
 		list_del_init(le);
 		xprt = list_entry(le, struct svc_xprt, xpt_list);
-		dprintk("svc_age_temp_xprts_now: closing %p\n", xprt);
-		xprt->xpt_ops->xpo_kill_temp_xprt(xprt);
-		svc_close_xprt(xprt);
+		set_bit(XPT_CLOSE, &xprt->xpt_flags);
+		set_bit(XPT_KILL_TEMP, &xprt->xpt_flags);
+		dprintk("svc_age_temp_xprts_now: queuing xprt %p for closing\n",
+				xprt);
+		svc_xprt_enqueue(xprt);
 	}
 }
 EXPORT_SYMBOL_GPL(svc_age_temp_xprts_now);

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/sunrpc-don-t-call-sleeping-functions-from-the-notifier-block-callbacks.patch