cifs: rcu-delay unload_nls() and freeing sbi

makes ->d_hash(), ->d_compare() and ->permission() safety in RCU mode
independent from vfsmount_lock.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2013-10-03 12:53:37 -04:00
parent baa40671d3
commit 2e32cf5ef2
2 changed files with 9 additions and 2 deletions

View File

@ -65,5 +65,6 @@ struct cifs_sb_info {
char *mountdata; /* options received at mount time or via DFS refs */
struct backing_dev_info bdi;
struct delayed_work prune_tlinks;
struct rcu_head rcu;
};
#endif /* _CIFS_FS_SB_H */

View File

@ -3755,6 +3755,13 @@ CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
return rc;
}
static void delayed_free(struct rcu_head *p)
{
struct cifs_sb_info *sbi = container_of(p, struct cifs_sb_info, rcu);
unload_nls(sbi->local_nls);
kfree(sbi);
}
void
cifs_umount(struct cifs_sb_info *cifs_sb)
{
@ -3779,8 +3786,7 @@ cifs_umount(struct cifs_sb_info *cifs_sb)
bdi_destroy(&cifs_sb->bdi);
kfree(cifs_sb->mountdata);
unload_nls(cifs_sb->local_nls);
kfree(cifs_sb);
call_rcu(&cifs_sb->rcu, delayed_free);
}
int