Btrfs: use seqlock to protect fs_info->avail_{data, metadata, system}_alloc_bits
There is no lock to protect
fs_info->avail_{data, metadata, system}_alloc_bits,
it may introduce some problem, such as the wrong profile
information, so we add a seqlock to protect them.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 50def99..5f5c30a 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1483,6 +1483,8 @@
struct rb_root defrag_inodes;
atomic_t defrag_running;
+ /* Used to protect avail_{data, metadata, system}_alloc_bits */
+ seqlock_t profiles_lock;
/*
* these three are in extended format (availability of single
* chunks is denoted by BTRFS_AVAIL_ALLOC_BIT_SINGLE bit, other