[PATCH] reiserfs: Fix softlockup while waiting on an inode

From: Frederic Weisbecker
Date: Thu Feb 11 2010 - 13:35:37 EST


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@xxxxxxxxx>
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Christian Kujau <lists@xxxxxxxxxxxxxxx>
Cc: Chris Mason <chris.mason@xxxxxxxxxx>
---
fs/reiserfs/inode.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index 9087b10..2df0f5c 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);

--
1.6.2.3

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