Re: [PATCH 1/1] vfs: umount_begin BKL pushdown v2

Al Viro
2009-04-24T07:13:36Z

On Fri, Apr 24, 2009 at 09:06:53AM +0200, Alessio Igor Bogani wrote:
> static void cifs_umount_begin(struct super_block *sb)
> {
> - struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
> + struct cifs_sb_info *cifs_sb;
> struct cifsTconInfo *tcon;
>
> - if (cifs_sb == NULL)
> + lock_kernel();
> + cifs_sb = CIFS_SB(sb);
> +
> + if (cifs_sb == NULL) {
> + unlock_kernel();
> return;
> + }
>
> tcon = cifs_sb->tcon;
> - if (tcon == NULL)
> + if (tcon == NULL) {
> + unlock_kernel();
> return;
> + }

AFAICS, both CIFS_SB(sb) and ->tcon are assign-once, so lock_kernel() should
really go here (if it can't be removed completely, of course, but that's up
to CIFS folks). Applied with such modification.