fs: update s_writers.frozen before calling ->unfreeze_fs

That way fіle systems can add asserts that ensure certain activity
don't happen on a completely frozen (SB_FREEZE_COMPLETE) superblock
while still allowing for said activity during unfreeze.

Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/fs/super.c b/fs/super.c
index 5a7db4a556e37323ab89b5e9f5ec7d323c3d029d..3a259ffd407202c87e375c3dc146c238d092c5a2 100644 (file)
--- a/fs/super.c
+++ b/fs/super.c
@@ -2170,6 +2170,9 @@ static int thaw_super_locked(struct super_block *sb, enum freeze_holder who)
 
        lockdep_sb_freeze_acquire(sb);
 
+       sb->s_writers.frozen = SB_FREEZE_FS;
+       wmb();
+
        if (sb->s_op->unfreeze_fs) {
                error = sb->s_op->unfreeze_fs(sb);
                if (error) {