From c138dcc2f902d99474527efba01aaa58603b7552 Mon Sep 17 00:00:00 2001
From: yangsheng <yangsheng>
Date: Tue, 14 Apr 2009 15:42:04 +0000
Subject: [PATCH] Branch b1_8 b=18399

i=adilger, johann

Patch kernel to avoid deadlock in prune_icache().
Authro: ZhaoHongChao
---
 lustre/ChangeLog                                            |  5 +++++
 .../patches/prune-icache-use-trylock-rhel5.patch            | 13 +++++++++++++
 .../patches/prune-icache-use-trylock-sles10.patch           | 13 +++++++++++++
 lustre/kernel_patches/series/2.6-rhel5.series               |  1 +
 lustre/kernel_patches/series/2.6-sles10.series              |  1 +
 5 files changed, 33 insertions(+)
 create mode 100644 lustre/kernel_patches/patches/prune-icache-use-trylock-rhel5.patch
 create mode 100644 lustre/kernel_patches/patches/prune-icache-use-trylock-sles10.patch

diff --git a/lustre/ChangeLog b/lustre/ChangeLog
index d3a5976..4e1c7d9 100644
--- a/lustre/ChangeLog
+++ b/lustre/ChangeLog
@@ -31,6 +31,11 @@ tbd Sun Microsystems, Inc.
 	  of Lustre filesystem with 4K stack may cause a stack overflow. For
 	  more information, please refer to bugzilla 17630.
 
+Severity   : normal
+Bugzilla   : 18399
+Descriptoin: OSS DeadLock
+Details    : Use trylock to prevent deadlock when shrink icache.
+
 Severity   : enhancement
 Bugzilla   : 18688
 Description: Allow tuning service thread via /proc
diff --git a/lustre/kernel_patches/patches/prune-icache-use-trylock-rhel5.patch b/lustre/kernel_patches/patches/prune-icache-use-trylock-rhel5.patch
new file mode 100644
index 0000000..beadec2
--- /dev/null
+++ b/lustre/kernel_patches/patches/prune-icache-use-trylock-rhel5.patch
@@ -0,0 +1,13 @@
+--- linux/fs/inode.c.orig	2009-01-24 03:28:57.000000000 +0800
++++ linux/fs/inode.c	2009-01-24 03:30:18.000000000 +0800
+@@ -418,7 +418,9 @@ static void prune_icache(int nr_to_scan)
+ 	int nr_scanned;
+ 	unsigned long reap = 0;
+ 
+-	mutex_lock(&iprune_mutex);
++	if (!mutex_trylock(&iprune_mutex))
++		return;
++
+ 	spin_lock(&inode_lock);
+ 	for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) {
+ 		struct inode *inode;
diff --git a/lustre/kernel_patches/patches/prune-icache-use-trylock-sles10.patch b/lustre/kernel_patches/patches/prune-icache-use-trylock-sles10.patch
new file mode 100644
index 0000000..51924f6
--- /dev/null
+++ b/lustre/kernel_patches/patches/prune-icache-use-trylock-sles10.patch
@@ -0,0 +1,13 @@
+--- linux/fs/inode.c.orig	2009-01-24 03:28:57.000000000 +0800
++++ linux/fs/inode.c	2009-01-24 03:30:18.000000000 +0800
+@@ -418,7 +418,9 @@ static void prune_icache(int nr_to_scan)
+ 	int nr_scanned;
+ 	unsigned long reap = 0;
+ 
+-	down(&iprune_sem);
++	if (down_trylock(&iprune_sem))
++		return;
++
+ 	spin_lock(&inode_lock);
+ 	for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) {
+ 		struct inode *inode;
diff --git a/lustre/kernel_patches/series/2.6-rhel5.series b/lustre/kernel_patches/series/2.6-rhel5.series
index 71e15ef..f43347a 100644
--- a/lustre/kernel_patches/series/2.6-rhel5.series
+++ b/lustre/kernel_patches/series/2.6-rhel5.series
@@ -21,3 +21,4 @@ md-soft-lockups.patch
 jbd-journal-chksum-2.6.18-vanilla.patch
 quota-large-limits-rhel5.patch
 md-mmp-unplug-dev.patch
+prune-icache-use-trylock-rhel5.patch
diff --git a/lustre/kernel_patches/series/2.6-sles10.series b/lustre/kernel_patches/series/2.6-sles10.series
index ae293be..dcc8c04 100644
--- a/lustre/kernel_patches/series/2.6-sles10.series
+++ b/lustre/kernel_patches/series/2.6-sles10.series
@@ -12,3 +12,4 @@ jbd-stats-2.6-sles10.patch
 quota-fix-oops-in-invalidate_dquots.patch
 quota-large-limits-sles10.patch
 md-mmp-unplug-dev-sles10.patch
+prune-icache-use-trylock-sles10.patch
-- 
1.8.3.1