[PATCH] Btrfs: fix passing wrong arg gfp_t to decide the correct allocation mode

[Wang Shilong <wangsl-fnst@cn.fujitsu.com>]

If you look the code carefully, you will see all the tree_mod_alloc()
has to use GFP_ATOMIC. However, the original code pass the wrong arg
gfp_t in some places, this dosen't cause any problems, because in the
tree_mod_alloc(), it ignores arg gfp_t and just use GFP_ATOMIC directly,
this is not good.

However, i think we should try best not to allocate with GFP_ATOMIC, so
i keep the gfp_t there in the hope we can change allocation mode in the
future.

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
---
 fs/btrfs/ctree.c |   37 ++++++++++++++++++-------------------
 1 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index de6de8e..33c9061 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -553,7 +553,7 @@ static inline int tree_mod_alloc(struct btrfs_fs_info *fs_info, gfp_t flags,
 	 * once we switch from spin locks to something different, we should
 	 * honor the flags parameter here.
 	 */
-	tm = *tm_ret = kzalloc(sizeof(*tm), GFP_ATOMIC);
+	tm = *tm_ret = kzalloc(sizeof(*tm), flags);
 	if (!tm)
 		return -ENOMEM;
 
@@ -591,14 +591,14 @@ __tree_mod_log_insert_key(struct btrfs_fs_info *fs_info,
 static noinline int
 tree_mod_log_insert_key_mask(struct btrfs_fs_info *fs_info,
 			     struct extent_buffer *eb, int slot,
-			     enum mod_log_op op, gfp_t flags)
+			     enum mod_log_op op)
 {
 	int ret;
 
 	if (tree_mod_dont_log(fs_info, eb))
 		return 0;
 
-	ret = __tree_mod_log_insert_key(fs_info, eb, slot, op, flags);
+	ret = __tree_mod_log_insert_key(fs_info, eb, slot, op, GFP_ATOMIC);
 
 	tree_mod_log_write_unlock(fs_info);
 	return ret;
@@ -608,7 +608,7 @@ static noinline int
 tree_mod_log_insert_key(struct btrfs_fs_info *fs_info, struct extent_buffer *eb,
 			int slot, enum mod_log_op op)
 {
-	return tree_mod_log_insert_key_mask(fs_info, eb, slot, op, GFP_NOFS);
+	return tree_mod_log_insert_key_mask(fs_info, eb, slot, op);
 }
 
 static noinline int
@@ -616,13 +616,13 @@ tree_mod_log_insert_key_locked(struct btrfs_fs_info *fs_info,
 			     struct extent_buffer *eb, int slot,
 			     enum mod_log_op op)
 {
-	return __tree_mod_log_insert_key(fs_info, eb, slot, op, GFP_NOFS);
+	return __tree_mod_log_insert_key(fs_info, eb, slot, op, GFP_ATOMIC);
 }
 
 static noinline int
 tree_mod_log_insert_move(struct btrfs_fs_info *fs_info,
 			 struct extent_buffer *eb, int dst_slot, int src_slot,
-			 int nr_items, gfp_t flags)
+			 int nr_items)
 {
 	struct tree_mod_elem *tm;
 	int ret;
@@ -642,7 +642,7 @@ tree_mod_log_insert_move(struct btrfs_fs_info *fs_info,
 		BUG_ON(ret < 0);
 	}
 
-	ret = tree_mod_alloc(fs_info, flags, &tm);
+	ret = tree_mod_alloc(fs_info, GFP_ATOMIC, &tm);
 	if (ret < 0)
 		goto out;
 
@@ -679,7 +679,7 @@ __tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, struct extent_buffer *eb)
 static noinline int
 tree_mod_log_insert_root(struct btrfs_fs_info *fs_info,
 			 struct extent_buffer *old_root,
-			 struct extent_buffer *new_root, gfp_t flags,
+			 struct extent_buffer *new_root,
 			 int log_removal)
 {
 	struct tree_mod_elem *tm;
@@ -691,7 +691,7 @@ tree_mod_log_insert_root(struct btrfs_fs_info *fs_info,
 	if (log_removal)
 		__tree_mod_log_free_eb(fs_info, old_root);
 
-	ret = tree_mod_alloc(fs_info, flags, &tm);
+	ret = tree_mod_alloc(fs_info, GFP_ATOMIC, &tm);
 	if (ret < 0)
 		goto out;
 
@@ -809,19 +809,18 @@ tree_mod_log_eb_move(struct btrfs_fs_info *fs_info, struct extent_buffer *dst,
 {
 	int ret;
 	ret = tree_mod_log_insert_move(fs_info, dst, dst_offset, src_offset,
-				       nr_items, GFP_NOFS);
+				       nr_items);
 	BUG_ON(ret < 0);
 }
 
 static noinline void
 tree_mod_log_set_node_key(struct btrfs_fs_info *fs_info,
-			  struct extent_buffer *eb, int slot, int atomic)
+			  struct extent_buffer *eb, int slot)
 {
 	int ret;
 
 	ret = tree_mod_log_insert_key_mask(fs_info, eb, slot,
-					   MOD_LOG_KEY_REPLACE,
-					   atomic ? GFP_ATOMIC : GFP_NOFS);
+					   MOD_LOG_KEY_REPLACE);
 	BUG_ON(ret < 0);
 }
 
@@ -843,7 +842,7 @@ tree_mod_log_set_root_pointer(struct btrfs_root *root,
 {
 	int ret;
 	ret = tree_mod_log_insert_root(root->fs_info, root->node,
-				       new_root_node, GFP_NOFS, log_removal);
+				       new_root_node, log_removal);
 	BUG_ON(ret < 0);
 }
 
@@ -1886,7 +1885,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 			struct btrfs_disk_key right_key;
 			btrfs_node_key(right, &right_key, 0);
 			tree_mod_log_set_node_key(root->fs_info, parent,
-						  pslot + 1, 0);
+						  pslot + 1);
 			btrfs_set_node_key(parent, &right_key, pslot + 1);
 			btrfs_mark_buffer_dirty(parent);
 		}
@@ -1931,7 +1930,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 		struct btrfs_disk_key mid_key;
 		btrfs_node_key(mid, &mid_key, 0);
 		tree_mod_log_set_node_key(root->fs_info, parent,
-					  pslot, 0);
+					  pslot);
 		btrfs_set_node_key(parent, &mid_key, pslot);
 		btrfs_mark_buffer_dirty(parent);
 	}
@@ -2030,7 +2029,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
 			orig_slot += left_nr;
 			btrfs_node_key(mid, &disk_key, 0);
 			tree_mod_log_set_node_key(root->fs_info, parent,
-						  pslot, 0);
+						  pslot);
 			btrfs_set_node_key(parent, &disk_key, pslot);
 			btrfs_mark_buffer_dirty(parent);
 			if (btrfs_header_nritems(left) > orig_slot) {
@@ -2083,7 +2082,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
 
 			btrfs_node_key(right, &disk_key, 0);
 			tree_mod_log_set_node_key(root->fs_info, parent,
-						  pslot + 1, 0);
+						  pslot + 1);
 			btrfs_set_node_key(parent, &disk_key, pslot + 1);
 			btrfs_mark_buffer_dirty(parent);
 
@@ -2963,7 +2962,7 @@ static void fixup_low_keys(struct btrfs_root *root, struct btrfs_path *path,
 		if (!path->nodes[i])
 			break;
 		t = path->nodes[i];
-		tree_mod_log_set_node_key(root->fs_info, t, tslot, 1);
+		tree_mod_log_set_node_key(root->fs_info, t, tslot);
 		btrfs_set_node_key(t, key, tslot);
 		btrfs_mark_buffer_dirty(path->nodes[i]);
 		if (tslot != 0)
-- 
1.7.7.6