readahead: combine file_ra_state.prev_index/prev_offset into prev_pos

Combine the file_ra_state members
				unsigned long prev_index
				unsigned int prev_offset
into
				loff_t prev_pos

It is more consistent and better supports huge files.

Thanks to Peter for the nice proposal!

[akpm@linux-foundation.org: fix shift overflow]
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 3ab01c04e00c..e11890acfa21 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -142,7 +142,7 @@ static int ext4_readdir(struct file * filp,
                                         sb->s_bdev->bd_inode->i_mapping,
                                         &filp->f_ra, filp,
                                         index, 1);
-                        filp->f_ra.prev_index = index;
+                        filp->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
                         bh = ext4_bread(NULL, inode, blk, 0, &err);
                 }