X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=fs%2Fext2%2Finode.c;h=0aa9bf6e6e53e2d1ac14d26917d6afa1b6fae233;hb=01504f5e9e071f1dde1062e3be15f54d4555308f;hp=c60a248c640cb9f23494ed3442ad161639922e7b;hpb=38dab9ac1c017e96dc98e978111e365134d41d13;p=firefly-linux-kernel-4.4.55.git

diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index c60a248c640c..0aa9bf6e6e53 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -1085,6 +1085,7 @@ static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int de
 		ext2_free_data(inode, p, q);
 }
 
+/* dax_sem must be held when calling this function */
 static void __ext2_truncate_blocks(struct inode *inode, loff_t offset)
 {
 	__le32 *i_data = EXT2_I(inode)->i_data;
@@ -1100,6 +1101,10 @@ static void __ext2_truncate_blocks(struct inode *inode, loff_t offset)
 	blocksize = inode->i_sb->s_blocksize;
 	iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb);
 
+#ifdef CONFIG_FS_DAX
+	WARN_ON(!rwsem_is_locked(&ei->dax_sem));
+#endif
+
 	n = ext2_block_to_path(inode, iblock, offsets, NULL);
 	if (n == 0)
 		return;
@@ -1185,7 +1190,10 @@ static void ext2_truncate_blocks(struct inode *inode, loff_t offset)
 		return;
 	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 		return;
+
+	dax_sem_down_write(EXT2_I(inode));
 	__ext2_truncate_blocks(inode, offset);
+	dax_sem_up_write(EXT2_I(inode));
 }
 
 static int ext2_setsize(struct inode *inode, loff_t newsize)
@@ -1213,8 +1221,10 @@ static int ext2_setsize(struct inode *inode, loff_t newsize)
 	if (error)
 		return error;
 
+	dax_sem_down_write(EXT2_I(inode));
 	truncate_setsize(inode, newsize);
 	__ext2_truncate_blocks(inode, newsize);
+	dax_sem_up_write(EXT2_I(inode));
 
 	inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
 	if (inode_needs_sync(inode)) {