Commit 1b327b5a authored by Al Viro's avatar Al Viro
Browse files

kill DCACHE_MAY_FREE 



With the new ordering in __dentry_kill() it has become redundant -
it's set if and only if both DCACHE_DENTRY_KILLED and DCACHE_SHRINK_LIST
are set.

We set it in __dentry_kill(), after having set DCACHE_DENTRY_KILLED
with the only condition being that DCACHE_SHRINK_LIST is there;
all of that is done without dropping ->d_lock and the only place
that checks that flag (shrink_dentry_list()) does so under ->d_lock,
after having found the victim on its shrink list.  Since DCACHE_SHRINK_LIST
is set only when placing dentry into shrink list and removed only by
shrink_dentry_list() itself, a check for DCACHE_DENTRY_KILLED in
there would be equivalent to check for DCACHE_MAY_FREE.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 119dcc73

fs/dcache.c

+2 −4
Original line number Diff line number Diff line
@@ -614,10 +614,8 @@ static struct dentry *__dentry_kill(struct dentry *dentry) 
	}

	spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);

	dentry_unlist(dentry);

	if (dentry->d_flags & DCACHE_SHRINK_LIST) {

		dentry->d_flags |= DCACHE_MAY_FREE;

	if (dentry->d_flags & DCACHE_SHRINK_LIST)

		can_free = false;

	}

	spin_unlock(&dentry->d_lock);

	if (likely(can_free))

		dentry_free(dentry);
@@ -1072,7 +1070,7 @@ void shrink_dentry_list(struct list_head *list) 
			bool can_free;

			rcu_read_unlock();

			d_shrink_del(dentry);

			can_free = dentry->d_flags & DCACHE_MAY_FREE;

			can_free = dentry->d_flags & DCACHE_DENTRY_KILLED;

			spin_unlock(&dentry->d_lock);

			if (can_free)

				dentry_free(dentry);

include/linux/dcache.h

+0 −1
Original line number Diff line number Diff line
@@ -202,7 +202,6 @@ struct dentry_operations { 
#define DCACHE_SPECIAL_TYPE		(5 << 20) /* Other file type */

#define DCACHE_SYMLINK_TYPE		(6 << 20) /* Symlink */



#define DCACHE_MAY_FREE			BIT(23)

#define DCACHE_NOKEY_NAME		BIT(25) /* Encrypted name encoded without key */

#define DCACHE_OP_REAL			BIT(26)