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>