GFS2: Protect freeing directory hash table with i_lock spin_lock

PATCH Superseded Bob Peterson 1 participant 1 message Oct 29, 2015 1 message not in the archive GFS2 file system

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Bob Peterson

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2015-10-29 15:12 UTC #1 lore raw

PATCH 1/1 GFS2: Protect freeing directory hash table with i_lock spin_lock

Hi,

This patch changes function gfs2_dir_hash_inval so that it uses the i_lock spin_lock to protect the in-core hash table, i_hash_cache. This will prevent double-frees due to a race between gfs2_clear_inode and inode invalidation.

Signed-off-by Bob Peterson <[email protected]>

---

fs/gfs2/dir.c +6 -1

index 487527b..ad8a5b7 100644
@@ -388,8 +388,13 @@ static __be64 *gfs2_dir_get_hash_table(struct gfs2_inode *ip)
  */
 void gfs2_dir_hash_inval(struct gfs2_inode *ip)
 {
-	__be64 *hc = ip->i_hash_cache;
+	__be64 *hc;
+
+	spin_lock(&ip->i_inode.i_lock);
+	hc = ip->i_hash_cache;
 	ip->i_hash_cache = NULL;
+	spin_unlock(&ip->i_inode.i_lock);
+
 	kvfree(hc);
 }