From: Felix Blyakher <felixb@sgi.com>
Date: Mon, 1 Jun 2009 18:13:24 +0000 (-0500)
Subject: xfs: prevent deadlock in xfs_qm_shake()
X-Git-Tag: archive/raspbian/4.9.13-1+rpi1~10^2~22444^2
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks:///%22http:/www.example.com/cgi/%22https:/%22bookmarks:/?a=commitdiff_plain;h=1b17d766463d51904cb242f194a780737e5f73ef;p=linux-4.9.git

xfs: prevent deadlock in xfs_qm_shake()

It's possible to recurse into filesystem from the memory
allocation, which deadlocks in xfs_qm_shake(). Add check
for __GFP_FS, and bail out if it is not set.

Signed-off-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Hedi Berriche <hedi@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
---

diff --git a/fs/xfs/linux-2.6/kmem.h b/fs/xfs/linux-2.6/kmem.h
index af6843c7ee4b..179cbd630f69 100644
--- a/fs/xfs/linux-2.6/kmem.h
+++ b/fs/xfs/linux-2.6/kmem.h
@@ -103,7 +103,7 @@ extern void *kmem_zone_zalloc(kmem_zone_t *, unsigned int __nocast);
 static inline int
 kmem_shake_allow(gfp_t gfp_mask)
 {
-	return (gfp_mask & __GFP_WAIT) != 0;
+	return ((gfp_mask & __GFP_WAIT) && (gfp_mask & __GFP_FS));
 }
 
 #endif /* __XFS_SUPPORT_KMEM_H__ */