lift the "already marked killed" case into shrink_dentry_list()

It can happen only when dentry_kill() is called with unlock_on_failure
equal to 0 - other callers had dentry pinned until the moment they've
got ->d_lock and DCACHE_DENTRY_KILLED is set only after lockref_mark_dead().

IOW, only one of three call sites of dentry_kill() might end up reaching
that code.  Just move it there.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2014-05-28 09:48:44 -04:00
parent b6dd6f4738
commit 64fd72e0a4

View File

@ -455,12 +455,6 @@ dentry_kill(struct dentry *dentry, int unlock_on_failure)
struct dentry *parent = NULL;
bool can_free = true;
if (unlikely(dentry->d_flags & DCACHE_DENTRY_KILLED)) {
can_free = dentry->d_flags & DCACHE_MAY_FREE;
spin_unlock(&dentry->d_lock);
goto out;
}
inode = dentry->d_inode;
if (inode && !spin_trylock(&inode->i_lock)) {
relock:
@ -815,6 +809,15 @@ static void shrink_dentry_list(struct list_head *list)
continue;
}
if (unlikely(dentry->d_flags & DCACHE_DENTRY_KILLED)) {
bool can_free = dentry->d_flags & DCACHE_MAY_FREE;
spin_unlock(&dentry->d_lock);
if (can_free)
dentry_free(dentry);
continue;
}
parent = dentry_kill(dentry, 0);
/*
* If dentry_kill returns NULL, we have nothing more to do.