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

Greg Kroah-Hartman
2016-05-17T01:27:54Z

From: Zhao Lei <zhaolei@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 <zhaolei@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@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);