[PATCH 18/38] vfs: Use sget_fc() for pseudo-filesystems

[David Howells]

Signed-off-by: David Howells <dhowe...@redhat.com>
cc: linux-fsde...@vger.kernel.org
---

 fs/libfs.c |   25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/fs/libfs.c b/fs/libfs.c
index 9a15590b65da..f6710316de00 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -242,18 +242,12 @@ struct pseudo_fs_context {
        unsigned long magic;
 };
 
-static int pseudo_fs_get_tree(struct fs_context *fc)
+static int pseudo_fs_fill_super(struct super_block *s, struct fs_context *fc)
 {
        struct pseudo_fs_context *ctx = fc->fs_private;
-       struct super_block *s;
        struct dentry *dentry;
        struct inode *root;
 
-       s = sget_userns(fc->fs_type, NULL, set_anon_super, 
SB_KERNMOUNT|SB_NOUSER,
-                       &init_user_ns, NULL);
-       if (IS_ERR(s))
-               return PTR_ERR(s);
-
        s->s_maxbytes = MAX_LFS_FILESIZE;
        s->s_blocksize = PAGE_SIZE;
        s->s_blocksize_bits = PAGE_SHIFT;
@@ -263,7 +257,8 @@ static int pseudo_fs_get_tree(struct fs_context *fc)
        s->s_time_gran = 1;
        root = new_inode(s);
        if (!root)
-               goto Enomem;
+               return -ENOMEM;
+
        /*
         * since this is the first inode, make it number 1. New inodes created
         * after this must take care not to collide with it (by passing
@@ -275,18 +270,17 @@ static int pseudo_fs_get_tree(struct fs_context *fc)
        dentry = __d_alloc(s, &ctx->d_name);
        if (!dentry) {
                iput(root);
-               goto Enomem;
+               return -ENOMEM;
        }
        d_instantiate(dentry, root);
        s->s_root = dentry;
        s->s_d_op = ctx->dops;
-       s->s_flags |= SB_ACTIVE;
-       fc->root = dget(s->s_root);
        return 0;
+}
 
-Enomem:
-       deactivate_locked_super(s);
-       return -ENOMEM;
+static int pseudo_fs_get_tree(struct fs_context *fc)
+{
+       return vfs_get_super(fc, vfs_get_independent_super, 
pseudo_fs_fill_super);
 }
 
 static void pseudo_fs_free(struct fs_context *fc)
@@ -320,6 +314,9 @@ int vfs_init_pseudo_fs_context(struct fs_context *fc,
        ctx->xattr = xattr;
        ctx->dops = dops;
        ctx->magic = magic;
+
+       fc->sb_flags = SB_KERNMOUNT | SB_NOUSER;
+       fc->global = true;
        fc->fs_private = ctx;
        fc->ops = &pseudo_fs_context_ops;
        return 0;