From aea52e19dd2085617dd7d247afb76a90cf2ea40c Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 17 Nov 2011 01:22:46 -0500 Subject: [PATCH] btrfs: get ->kill_sb() of its own ... and move free_fs_info() to that, out of ->put_super(). Do NOT set ->s_fs_info to NULL in the latter; we need it for sget() to be able to see and wait for fs in the middle of umount if we get a mount/umount race. Signed-off-by: Al Viro --- fs/btrfs/super.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index a3f435e5898..eca48624a4f 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -147,14 +147,13 @@ void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function, static void btrfs_put_super(struct super_block *sb) { - struct btrfs_root *root = btrfs_sb(sb); - int ret; - - ret = close_ctree(root); - free_fs_info(root->fs_info); - sb->s_fs_info = NULL; - - (void)ret; /* FIXME: need to fix VFS to return error? */ + (void)close_ctree(btrfs_sb(sb)); + /* FIXME: need to fix VFS to return error? */ + /* AV: return it _where_? ->put_super() can be triggered by any number + * of async events, up to and including delivery of SIGKILL to the + * last process that kept it busy. Or segfault in the aforementioned + * process... Whom would you report that to? + */ } enum { @@ -1223,11 +1222,21 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) return 0; } +static void btrfs_kill_super(struct super_block *sb) +{ + struct btrfs_fs_info *fs_info = NULL; + if (sb->s_root) + fs_info = btrfs_sb(sb)->fs_info; + kill_anon_super(sb); + if (fs_info) + free_fs_info(fs_info); +} + static struct file_system_type btrfs_fs_type = { .owner = THIS_MODULE, .name = "btrfs", .mount = btrfs_mount, - .kill_sb = kill_anon_super, + .kill_sb = btrfs_kill_super, .fs_flags = FS_REQUIRES_DEV, };