From: Theodore Ts'o Date: Mon, 18 May 2009 03:31:23 +0000 (-0400) Subject: ext4: down i_data_sem only for read when walking tree for fiemap X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=0568c518937ee3a9b6a94d18bae9c150fe5d6832;p=deliverable%2Flinux.git ext4: down i_data_sem only for read when walking tree for fiemap Not sure why I put this in as down_write originally; all we are doing is walking the tree, nothing will change under us and concurrent reads should be no problem. Signed-off-by: Eric Sandeen Signed-off-by: "Theodore Ts'o" --- diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index d04b779b780e..d4e99e96fddb 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3312,10 +3312,10 @@ int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, * Walk the extent tree gathering extent information. * ext4_ext_fiemap_cb will push extents back to user. */ - down_write(&EXT4_I(inode)->i_data_sem); + down_read(&EXT4_I(inode)->i_data_sem); error = ext4_ext_walk_space(inode, start_blk, len_blks, ext4_ext_fiemap_cb, fieinfo); - up_write(&EXT4_I(inode)->i_data_sem); + up_read(&EXT4_I(inode)->i_data_sem); } return error;