lift the "already marked killed" case into shrink_dentry_list() (64fd72e0) · Commits · 戴 / test

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>

fs/dcache.c

+9 −6

Original line number	Diff line number	Diff line
		@@ -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.

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