From: Fan Li <fanofcode.li@samsung.com>
Date: Mon, 4 Jan 2016 07:56:50 +0000 (+0800)
Subject: f2fs: read isize while holding i_mutex in fiemap
X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=de1475cc53b2d6442443dcf5d66ed0fc50ed3c7e;p=openwrt%2Fstaging%2Fblogic.git

f2fs: read isize while holding i_mutex in fiemap

make sure the isize we read doesn't change during the process.

Signed-off-by: Fan li <fanofcode.li@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 89a978c57da9..ac5bea0f5f09 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -784,7 +784,7 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 {
 	struct buffer_head map_bh;
 	sector_t start_blk, last_blk;
-	loff_t isize = i_size_read(inode);
+	loff_t isize;
 	u64 logical = 0, phys = 0, size = 0;
 	u32 flags = 0;
 	int ret = 0;
@@ -800,6 +800,8 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 	}
 
 	mutex_lock(&inode->i_mutex);
+
+	isize = i_size_read(inode);
 	if (start >= isize)
 		goto out;