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Commit 2edbfbf1 authored by Al Viro's avatar Al Viro
Browse files

ecryptfs: don't leave RCU pathwalk immediately 



If the underlying dentry doesn't have ->d_revalidate(), there's no need to
force dropping out of RCU mode.  All we need for that is to make freeing
ecryptfs_dentry_info RCU-delayed.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 3a93e17c

fs/ecryptfs/dentry.c

+16 −14
Original line number Diff line number Diff line
@@ -44,15 +44,15 @@ 
 */

static int ecryptfs_d_revalidate(struct dentry *dentry, unsigned int flags)

{

	struct dentry *lower_dentry;

	int rc = 1;

	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);

	int rc;



	if (!(lower_dentry->d_flags & DCACHE_OP_REVALIDATE))

		return 1;



	if (flags & LOOKUP_RCU)

		return -ECHILD;



	lower_dentry = ecryptfs_dentry_to_lower(dentry);

	if (!(lower_dentry->d_flags & DCACHE_OP_REVALIDATE))

		goto out;

	rc = lower_dentry->d_op->d_revalidate(lower_dentry, flags);

	if (dentry->d_inode) {

		struct inode *lower_inode =
@@ -60,12 +60,17 @@ static int ecryptfs_d_revalidate(struct dentry *dentry, unsigned int flags) 


		fsstack_copy_attr_all(dentry->d_inode, lower_inode);

	}

out:

	return rc;

}



struct kmem_cache *ecryptfs_dentry_info_cache;



static void ecryptfs_dentry_free_rcu(struct rcu_head *head)

{

	kmem_cache_free(ecryptfs_dentry_info_cache,

		container_of(head, struct ecryptfs_dentry_info, rcu));

}



/**

 * ecryptfs_d_release

 * @dentry: The ecryptfs dentry
@@ -74,15 +79,12 @@ struct kmem_cache *ecryptfs_dentry_info_cache; 
 */

static void ecryptfs_d_release(struct dentry *dentry)

{

	if (ecryptfs_dentry_to_private(dentry)) {

		if (ecryptfs_dentry_to_lower(dentry)) {

			dput(ecryptfs_dentry_to_lower(dentry));

			mntput(ecryptfs_dentry_to_lower_mnt(dentry));

		}

		kmem_cache_free(ecryptfs_dentry_info_cache,

				ecryptfs_dentry_to_private(dentry));

	struct ecryptfs_dentry_info *p = dentry->d_fsdata;

	if (p) {

		if (p->lower_path.dentry)

			path_put(&p->lower_path);

		call_rcu(&p->rcu, ecryptfs_dentry_free_rcu);

	}

	return;

}



const struct dentry_operations ecryptfs_dops = {

fs/ecryptfs/ecryptfs_kernel.h

+4 −1
Original line number Diff line number Diff line
@@ -261,7 +261,10 @@ struct ecryptfs_inode_info { 
 * vfsmount too. */

struct ecryptfs_dentry_info {

	struct path lower_path;

	union {

		struct ecryptfs_crypt_stat *crypt_stat;

		struct rcu_head rcu;

	};

};



/**