From d5ecd0bd9003dd23cc502563282e99eff7c8a895 Mon Sep 17 00:00:00 2001
From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Date: Wed, 20 Apr 2011 06:44:57 +0000
Subject: [PATCH] --- yaml --- r: 252335 b: refs/heads/master c:
 8233767a227ac5843f1023b88c7272a7b5058f5f h: refs/heads/master i:   252333:
 dbddc4bb1b044de85c56ff67dad04fc7e0d1a3a1   252331:
 788bb0ab12caac5931150ca6152f4a4e22877058   252327:
 68cda59ad7451925f13254ee79adafe7556fa445   252319:
 8ec786dd04d8e618d2fb1a635a9068078e4f3018 v: v3

---
 [refs]                     |  2 +-
 trunk/fs/btrfs/extent_io.c | 34 ++++++++++++++++++++++++++--------
 2 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/[refs] b/[refs]
index e3c87c3fcb8f..dc0861f549ba 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b083916638eee513be501f53b42a4be0b9851db0
+refs/heads/master: 8233767a227ac5843f1023b88c7272a7b5058f5f
diff --git a/trunk/fs/btrfs/extent_io.c b/trunk/fs/btrfs/extent_io.c
index ba41da59e31b..9ccea86dd015 100644
--- a/trunk/fs/btrfs/extent_io.c
+++ b/trunk/fs/btrfs/extent_io.c
@@ -439,6 +439,15 @@ static int clear_state_bit(struct extent_io_tree *tree,
 	return ret;
 }
 
+static struct extent_state *
+alloc_extent_state_atomic(struct extent_state *prealloc)
+{
+	if (!prealloc)
+		prealloc = alloc_extent_state(GFP_ATOMIC);
+
+	return prealloc;
+}
+
 /*
  * clear some bits on a range in the tree.  This may require splitting
  * or inserting elements in the tree, so the gfp mask is used to
@@ -476,8 +485,7 @@ int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 again:
 	if (!prealloc && (mask & __GFP_WAIT)) {
 		prealloc = alloc_extent_state(mask);
-		if (!prealloc)
-			return -ENOMEM;
+		BUG_ON(!prealloc);
 	}
 
 	spin_lock(&tree->lock);
@@ -529,8 +537,8 @@ int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 	 */
 
 	if (state->start < start) {
-		if (!prealloc)
-			prealloc = alloc_extent_state(GFP_ATOMIC);
+		prealloc = alloc_extent_state_atomic(prealloc);
+		BUG_ON(!prealloc);
 		err = split_state(tree, state, prealloc, start);
 		BUG_ON(err == -EEXIST);
 		prealloc = NULL;
@@ -551,8 +559,8 @@ int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 	 * on the first half
 	 */
 	if (state->start <= end && state->end > end) {
-		if (!prealloc)
-			prealloc = alloc_extent_state(GFP_ATOMIC);
+		prealloc = alloc_extent_state_atomic(prealloc);
+		BUG_ON(!prealloc);
 		err = split_state(tree, state, prealloc, end + 1);
 		BUG_ON(err == -EEXIST);
 		if (wake)
@@ -725,8 +733,7 @@ int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 again:
 	if (!prealloc && (mask & __GFP_WAIT)) {
 		prealloc = alloc_extent_state(mask);
-		if (!prealloc)
-			return -ENOMEM;
+		BUG_ON(!prealloc);
 	}
 
 	spin_lock(&tree->lock);
@@ -743,6 +750,8 @@ int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 	 */
 	node = tree_search(tree, start);
 	if (!node) {
+		prealloc = alloc_extent_state_atomic(prealloc);
+		BUG_ON(!prealloc);
 		err = insert_state(tree, prealloc, start, end, &bits);
 		prealloc = NULL;
 		BUG_ON(err == -EEXIST);
@@ -811,6 +820,9 @@ int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 			err = -EEXIST;
 			goto out;
 		}
+
+		prealloc = alloc_extent_state_atomic(prealloc);
+		BUG_ON(!prealloc);
 		err = split_state(tree, state, prealloc, start);
 		BUG_ON(err == -EEXIST);
 		prealloc = NULL;
@@ -841,6 +853,9 @@ int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 			this_end = end;
 		else
 			this_end = last_start - 1;
+
+		prealloc = alloc_extent_state_atomic(prealloc);
+		BUG_ON(!prealloc);
 		err = insert_state(tree, prealloc, start, this_end,
 				   &bits);
 		BUG_ON(err == -EEXIST);
@@ -865,6 +880,9 @@ int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 			err = -EEXIST;
 			goto out;
 		}
+
+		prealloc = alloc_extent_state_atomic(prealloc);
+		BUG_ON(!prealloc);
 		err = split_state(tree, state, prealloc, end + 1);
 		BUG_ON(err == -EEXIST);