writeback: initialize inode members that track writeback history

inode struct members that track cgroup writeback information
should be reinitialized when inode gets allocated from
kmem_cache. Otherwise, their values remain and get used by the
new inode.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
Fixes: d10c80955265 ("writeback: implement foreign cgroup inode bdi_writeback switching")
Signed-off-by: Jens Axboe <axboe@fb.com>
(cherry picked from commit 3d65ae4634ed8350aee98a4e6f4e41fe40c7d282)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

diff --git a/fs/inode.c b/fs/inode.c
index b0edef500590c3e49cd5f632640add63426a39d5..2c16b758831dd08715c3c6e270c97f00b6bed10c 100644 (file)
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -154,6 +154,12 @@ int inode_init_always(struct super_block *sb, struct inode *inode)
        inode->i_rdev = 0;
        inode->dirtied_when = 0;
 
+#ifdef CONFIG_CGROUP_WRITEBACK
+       inode->i_wb_frn_winner = 0;
+       inode->i_wb_frn_avg_time = 0;
+       inode->i_wb_frn_history = 0;
+#endif
+
        if (security_inode_alloc(inode))
                goto out;
        spin_lock_init(&inode->i_lock);