Commit 4a0962ab authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds
Browse files

dentries: Extract common code to remove dentry from lru 



Extract the common code to remove a dentry from the lru into a new function
dentry_lru_remove().

Two call sites used list_del() instead of list_del_init().  AFAIK the
performance of both is the same.  dentry_lru_remove() does a list_del_init().

As a result dentry->d_lru is now always empty when a dentry is freed.

Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent cf28b486

fs/dcache.c

+14 −28
Original line number Diff line number Diff line
@@ -95,6 +95,14 @@ static void d_free(struct dentry *dentry) 
		call_rcu(&dentry->d_u.d_rcu, d_callback);

}



static void dentry_lru_remove(struct dentry *dentry)

{

	if (!list_empty(&dentry->d_lru)) {

		list_del_init(&dentry->d_lru);

		dentry_stat.nr_unused--;

	}

}



/*

 * Release the dentry's inode, using the filesystem

 * d_iput() operation if defined.
@@ -211,13 +219,7 @@ repeat: 
unhash_it:

	__d_drop(dentry);

kill_it:

	/* If dentry was on d_lru list

	 * delete it from there

	 */

	if (!list_empty(&dentry->d_lru)) {

		list_del(&dentry->d_lru);

		dentry_stat.nr_unused--;

	}

	dentry_lru_remove(dentry);

	dentry = d_kill(dentry);

	if (dentry)

		goto repeat;
@@ -285,10 +287,7 @@ int d_invalidate(struct dentry * dentry) 
static inline struct dentry * __dget_locked(struct dentry *dentry)

{

	atomic_inc(&dentry->d_count);

	if (!list_empty(&dentry->d_lru)) {

		dentry_stat.nr_unused--;

		list_del_init(&dentry->d_lru);

	}

	dentry_lru_remove(dentry);

	return dentry;

}
@@ -404,10 +403,7 @@ static void prune_one_dentry(struct dentry * dentry) 


		if (dentry->d_op && dentry->d_op->d_delete)

			dentry->d_op->d_delete(dentry);

		if (!list_empty(&dentry->d_lru)) {

			list_del(&dentry->d_lru);

			dentry_stat.nr_unused--;

		}

		dentry_lru_remove(dentry);

		__d_drop(dentry);

		dentry = d_kill(dentry);

		spin_lock(&dcache_lock);
@@ -596,10 +592,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry) 


	/* detach this root from the system */

	spin_lock(&dcache_lock);

	if (!list_empty(&dentry->d_lru)) {

		dentry_stat.nr_unused--;

		list_del_init(&dentry->d_lru);

	}

	dentry_lru_remove(dentry);

	__d_drop(dentry);

	spin_unlock(&dcache_lock);
@@ -613,11 +606,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry) 
			spin_lock(&dcache_lock);

			list_for_each_entry(loop, &dentry->d_subdirs,

					    d_u.d_child) {

				if (!list_empty(&loop->d_lru)) {

					dentry_stat.nr_unused--;

					list_del_init(&loop->d_lru);

				}



				dentry_lru_remove(loop);

				__d_drop(loop);

				cond_resched_lock(&dcache_lock);

			}
@@ -799,10 +788,7 @@ resume: 
		struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);

		next = tmp->next;



		if (!list_empty(&dentry->d_lru)) {

			dentry_stat.nr_unused--;

			list_del_init(&dentry->d_lru);

		}

		dentry_lru_remove(dentry);

		/* 

		 * move only zero ref count dentries to the end 

		 * of the unused list for prune_dcache

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