[PATCH 4.5 084/101] btrfs: reada: Fix in-segment calculation for reada

[Greg Kroah-Hartman]

4.5-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Zhao Lei <zhao...@cn.fujitsu.com>

commit 503785306d182ab624a2232856ef8ab503ee85f9 upstream.

reada_zone->end is end pos of segment:
 end = start + cache->key.offset - 1;

So we need to use "<=" in condition to judge is a pos in the
segment.

The problem happened rearly, because logical pos rarely pointed
to last 4k of a blockgroup, but we need to fix it to make code
right in logic.

Signed-off-by: Zhao Lei <zhao...@cn.fujitsu.com>
Signed-off-by: David Sterba <dste...@suse.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 fs/btrfs/reada.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/btrfs/reada.c
+++ b/fs/btrfs/reada.c
@@ -265,7 +265,7 @@ static struct reada_zone *reada_find_zon
        spin_unlock(&fs_info->reada_lock);
 
        if (ret == 1) {
-               if (logical >= zone->start && logical < zone->end)
+               if (logical >= zone->start && logical <= zone->end)
                        return zone;
                spin_lock(&fs_info->reada_lock);
                kref_put(&zone->refcnt, reada_zone_release);
@@ -679,7 +679,7 @@ static int reada_start_machine_dev(struc
         */
        ret = radix_tree_gang_lookup(&dev->reada_extents, (void **)&re,
                                     dev->reada_next >> PAGE_CACHE_SHIFT, 1);
-       if (ret == 0 || re->logical >= dev->reada_curr_zone->end) {
+       if (ret == 0 || re->logical > dev->reada_curr_zone->end) {
                ret = reada_pick_zone(dev);
                if (!ret) {
                        spin_unlock(&fs_info->reada_lock);