autofs: fix symlinks aren't checked for expiry

The autofs4 module doesn't consider symlinks for expire as it did in the
older autofs v3 module (so it's actually a long standing regression).

The user space daemon has focused on the use of bind mounts instead of
symlinks for a long time now and that's why this has not been noticed.
But with the future addition of amd map parsing to automount(8), not to
mention amd itself (of am-utils), symlink expiry will be needed.

The direct and offset mount types can't be symlinks and the tree mounts of
version 4 were always real mounts so only indirect mounts need expire
symlinks.

Since the current users of the autofs4 module haven't reported this as a
problem to date this patch probably isn't a candidate for backport to
stable.

Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ian Kent 2014-01-23 15:55:01 -08:00 committed by Linus Torvalds
parent c24930a9bb
commit 8dc51fe5ab
2 changed files with 18 additions and 0 deletions

View File

@ -402,6 +402,20 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb,
goto next;
}
if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)) {
DPRINTK("checking symlink %p %.*s",
dentry, (int)dentry->d_name.len, dentry->d_name.name);
/*
* A symlink can't be "busy" in the usual sense so
* just check last used for expire timeout.
*/
if (autofs4_can_expire(dentry, timeout, do_now)) {
expired = dentry;
goto found;
}
goto next;
}
if (simple_empty(dentry))
goto next;

View File

@ -14,6 +14,10 @@
static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
if (ino && !autofs4_oz_mode(sbi))
ino->last_used = jiffies;
nd_set_link(nd, dentry->d_inode->i_private);
return NULL;
}