From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Thu, 11 Feb 2010 12:13:10 +0000 (+0100)
Subject: reiserfs: Fix softlockup while waiting on an inode
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=175359f89df39f4faed663c8cfd6ee0222d2fa1e;p=openwrt%2Fstaging%2Fblogic.git

reiserfs: Fix softlockup while waiting on an inode

When we wait for an inode through reiserfs_iget(), we hold
the reiserfs lock. And waiting for an inode may imply waiting
for its writeback. But the inode writeback path may also require
the reiserfs lock, which leads to a deadlock.

We just need to release the reiserfs lock from reiserfs_iget()
to fix this.

Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Cc: Chris Mason <chris.mason@oracle.com>
---

diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index 9087b10209e6..2df0f5c7c60b 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -1497,9 +1497,11 @@ struct inode *reiserfs_iget(struct super_block *s, const struct cpu_key *key)
 
 	args.objectid = key->on_disk_key.k_objectid;
 	args.dirid = key->on_disk_key.k_dir_id;
+	reiserfs_write_unlock(s);
 	inode = iget5_locked(s, key->on_disk_key.k_objectid,
 			     reiserfs_find_actor, reiserfs_init_locked_inode,
 			     (void *)(&args));
+	reiserfs_write_lock(s);
 	if (!inode)
 		return ERR_PTR(-ENOMEM);