From 530b5ecac51cc7ce61ccddd50868c632c4a47298 Mon Sep 17 00:00:00 2001
From: Andrew Deason <adeason@sinenomine.net>
Date: Wed, 20 Jul 2011 16:50:52 -0500
Subject: [PATCH] libafs: Rate-limit hard-mount waiting messages

Limit how often we log "hard-mount waiting for XXX" messages. Without
this, it is possible for a client with hard-mounts enabled to spam the
kernel log rather excessively (in extreme cases this can even panic
the machine on at least some Linux).

To keep things simple, just log approximately one message per volume
per hard-mount interval.

Change-Id: Ie82f68c5eae76519fcf1491164133c1955ed9c08
Reviewed-on: http://gerrit.openafs.org/5060
Tested-by: Derrick Brashear <shadow@dementia.org>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
---
 src/afs/afs.h         |  1 +
 src/afs/afs_analyze.c | 56 +++++++++++++++++++++++++++++++++++++++----
 2 files changed, 52 insertions(+), 5 deletions(-)

diff --git a/src/afs/afs.h b/src/afs/afs.h
index 413106cce..6bf4f0e1f 100644
--- a/src/afs/afs.h
+++ b/src/afs/afs.h
@@ -565,6 +565,7 @@ struct chservinfo {
 #define VBackup			4	/* is this a backup volume? */
 #define VForeign		8	/* this is a non-afs volume */
 #define VPartVisible		16	/* Volume's partition is visible on the client */
+#define VHardMount		32	/* we are hard-mount waiting for the vol */
 
 enum repstate { not_busy, end_not_busy = 6, rd_busy, rdwr_busy, offline };
 
diff --git a/src/afs/afs_analyze.c b/src/afs/afs_analyze.c
index fc65ca5c2..b6dbed814 100644
--- a/src/afs/afs_analyze.c
+++ b/src/afs/afs_analyze.c
@@ -388,26 +388,72 @@ afs_Analyze(struct afs_conn *aconn, struct rx_connection *rxconn,
 		((afid && afs_IsPrimaryCellNum(afid->Cell))
 		 || (cellp && afs_IsPrimaryCell(cellp)))) {
 		if (!afid) {
-		    afs_warnuser
-			("afs: hard-mount waiting for a vlserver to return to service\n");
+		    static int afs_vl_hm = 0;
+		    int warn = 0;
+		    if (!afs_vl_hm) {
+			afs_vl_hm = warn = 1;
+		    }
+		    if (warn) {
+			afs_warnuser
+		            ("afs: hard-mount waiting for a vlserver to return to service\n");
+		    }
 		    VSleep(hm_retry_int);
 		    afs_CheckServers(1, cellp);
 		    shouldRetry = 1;
+
+		    if (warn) {
+			afs_vl_hm = 0;
+		    }
 		} else {
+		    static int afs_unknown_vhm = 0;
+		    int warn = 0, vp_vhm = 0;
+
 		    tvp = afs_FindVolume(afid, READ_LOCK);
 		    if (!tvp || (tvp->states & VRO)) {
 			shouldRetry = hm_retry_RO;
 		    } else {
 			shouldRetry = hm_retry_RW;
 		    }
+
+		    /* Set 'warn' if we should afs_warnuser. Only let one
+		     * caller call afs_warnuser per hm_retry_int interval per
+		     * volume. */
+		    if (shouldRetry) {
+			if (tvp) {
+			    if (!(tvp->states & VHardMount)) {
+				tvp->states |= VHardMount;
+				warn = vp_vhm = 1;
+			    }
+			} else {
+			    if (!afs_unknown_vhm) {
+				afs_unknown_vhm = 1;
+				warn = 1;
+			    }
+			}
+		    }
+
 		    if (tvp)
 			afs_PutVolume(tvp, READ_LOCK);
+
 		    if (shouldRetry) {
-			afs_warnuser
-			    ("afs: hard-mount waiting for volume %u\n",
-			     afid->Fid.Volume);
+			if (warn) {
+			    afs_warnuser
+			        ("afs: hard-mount waiting for volume %u\n",
+			         afid->Fid.Volume);
+			}
+
 			VSleep(hm_retry_int);
 			afs_CheckServers(1, cellp);
+
+			if (vp_vhm) {
+			    tvp = afs_FindVolume(afid, READ_LOCK);
+			    if (tvp) {
+				tvp->states &= ~VHardMount;
+				afs_PutVolume(tvp, READ_LOCK);
+			    }
+			} else if (warn) {
+			    afs_unknown_vhm = 0;
+			}
 		    }
 		}
 	    } /* if (hm_retry_int ... */
-- 
2.39.5