From: Chao Yu <yuchao0@huawei.com>
Date: Tue, 11 Oct 2016 14:57:05 +0000 (+0800)
Subject: f2fs: fix to update largest extent under lock
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=1158df42b2c66b4c9f150615ae37a1cc7edb3c74;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git

f2fs: fix to update largest extent under lock

commit b691d98fdd4cc2514c60fd6975e6016da203e64f upstream.

In order to avoid racing problem, make largest extent cache being updated
under lock.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---

diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index d7369895a78a..1fbebcb33a9d 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -252,6 +252,7 @@ retry:
 int update_inode(struct inode *inode, struct page *node_page)
 {
 	struct f2fs_inode *ri;
+	struct extent_tree *et = F2FS_I(inode)->extent_tree;
 
 	f2fs_inode_synced(inode);
 
@@ -267,11 +268,13 @@ int update_inode(struct inode *inode, struct page *node_page)
 	ri->i_size = cpu_to_le64(i_size_read(inode));
 	ri->i_blocks = cpu_to_le64(inode->i_blocks);
 
-	if (F2FS_I(inode)->extent_tree)
-		set_raw_extent(&F2FS_I(inode)->extent_tree->largest,
-							&ri->i_ext);
-	else
+	if (et) {
+		read_lock(&et->lock);
+		set_raw_extent(&et->largest, &ri->i_ext);
+		read_unlock(&et->lock);
+	} else {
 		memset(&ri->i_ext, 0, sizeof(ri->i_ext));
+	}
 	set_raw_inline(inode, ri);
 
 	ri->i_atime = cpu_to_le64(inode->i_atime.tv_sec);