[PATCH 3/7] bcachefs: Make sure c->vfs_sb is set before starting fs

[Kent Overstreet <kent.overstreet@linux.dev>]

This is necessary for the new blk_holder_ops, which want the vfs
super_block available for synchronization.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
---
 fs/bcachefs/fs.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/fs/bcachefs/fs.c b/fs/bcachefs/fs.c
index 2c011a465588..459ca8259fc0 100644
--- a/fs/bcachefs/fs.c
+++ b/fs/bcachefs/fs.c
@@ -2218,9 +2218,10 @@ static int bch2_fs_get_tree(struct fs_context *fc)
 
 	bch2_opts_apply(&c->opts, opts);
 
-	ret = bch2_fs_start(c);
-	if (ret)
-		goto err_stop_fs;
+	/*
+	 * need to initialise sb and set c->vfs_sb _before_ starting fs,
+	 * for blk_holder_ops
+	 */
 
 	sb = sget(fc->fs_type, NULL, bch2_set_super, fc->sb_flags|SB_NOSEC, c);
 	ret = PTR_ERR_OR_ZERO(sb);
@@ -2282,6 +2283,10 @@ static int bch2_fs_get_tree(struct fs_context *fc)
 
 	sb->s_shrink->seeks = 0;
 
+	ret = bch2_fs_start(c);
+	if (ret)
+		goto err_put_super;
+
 	vinode = bch2_vfs_inode_get(c, BCACHEFS_ROOT_SUBVOL_INUM);
 	ret = PTR_ERR_OR_ZERO(vinode);
 	bch_err_msg(c, ret, "mounting: error getting root inode");
-- 
2.47.2