fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away
We don't have proper reference counting for this yet, so we run into
cases where the device is pulled and we OOPS on flushing the fs data.
This happens even though the dirty inodes have already been
migrated to the default_backing_dev_info.
Reported-by: Torsten Hilbrich <torsten.hilbrich@secunet.com>
Tested-by: Torsten Hilbrich <torsten.hilbrich@secunet.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/fs/super.c b/fs/super.c
index 7e9dd4c..0d89e93 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -71,6 +71,7 @@
#else
INIT_LIST_HEAD(&s->s_files);
#endif
+ s->s_bdi = &default_backing_dev_info;
INIT_LIST_HEAD(&s->s_instances);
INIT_HLIST_BL_HEAD(&s->s_anon);
INIT_LIST_HEAD(&s->s_inodes);
@@ -1003,6 +1004,7 @@
}
BUG_ON(!mnt->mnt_sb);
WARN_ON(!mnt->mnt_sb->s_bdi);
+ WARN_ON(mnt->mnt_sb->s_bdi == &default_backing_dev_info);
mnt->mnt_sb->s_flags |= MS_BORN;
error = security_sb_kern_mount(mnt->mnt_sb, flags, secdata);