Commit f4288844 authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

ovl: decide if revalidate needed on a per-dentry basis 



Allow completely skipping ->revalidate() on a per-dentry basis, in case the
underlying layers used for a dentry do not themselves have ->revalidate().

E.g. negative overlay dentry has no underlying layers, hence revalidate is
unnecessary.  Or if lower layer is remote but overlay dentry is pure-upper,
then can skip revalidate.

The following places need to update whether the dentry needs revalidate or
not:

 - fill-super (root dentry)
 - lookup
 - create
 - fh_to_dentry

Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 7925dad8

fs/overlayfs/dir.c

+3 −0
Original line number Diff line number Diff line
@@ -243,6 +243,9 @@ static int ovl_instantiate(struct dentry *dentry, struct inode *inode, 


	ovl_dir_modified(dentry->d_parent, false);

	ovl_dentry_set_upper_alias(dentry);

	ovl_dentry_update_reval(dentry, newdentry,

			DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE);



	if (!hardlink) {

		/*

		 * ovl_obtain_alias() can be called after ovl_create_real()

fs/overlayfs/export.c

+2 −0
Original line number Diff line number Diff line
@@ -324,6 +324,8 @@ static struct dentry *ovl_obtain_alias(struct super_block *sb, 
		if (upper_alias)

			ovl_dentry_set_upper_alias(dentry);

	}

	ovl_dentry_update_reval(dentry, upper,

			DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE);



	return d_instantiate_anon(dentry, inode);

fs/overlayfs/namei.c

+3 −0
Original line number Diff line number Diff line
@@ -1077,6 +1077,9 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 
			goto out_free_oe;

	}



	ovl_dentry_update_reval(dentry, upperdentry,

			DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE);



	revert_creds(old_cred);

	if (origin_path) {

		dput(origin_path->dentry);

fs/overlayfs/overlayfs.h

+2 −0
Original line number Diff line number Diff line
@@ -230,6 +230,8 @@ bool ovl_index_all(struct super_block *sb); 
bool ovl_verify_lower(struct super_block *sb);

struct ovl_entry *ovl_alloc_entry(unsigned int numlower);

bool ovl_dentry_remote(struct dentry *dentry);

void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry,

			     unsigned int mask);

bool ovl_dentry_weird(struct dentry *dentry);

enum ovl_path_type ovl_path_type(struct dentry *dentry);

void ovl_path_upper(struct dentry *dentry, struct path *path);

fs/overlayfs/super.c

+5 −16
Original line number Diff line number Diff line
@@ -158,11 +158,6 @@ static int ovl_dentry_weak_revalidate(struct dentry *dentry, unsigned int flags) 
static const struct dentry_operations ovl_dentry_operations = {

	.d_release = ovl_dentry_release,

	.d_real = ovl_d_real,

};



static const struct dentry_operations ovl_reval_dentry_operations = {

	.d_release = ovl_dentry_release,

	.d_real = ovl_d_real,

	.d_revalidate = ovl_dentry_revalidate,

	.d_weak_revalidate = ovl_dentry_weak_revalidate,

};
@@ -779,7 +774,7 @@ static int ovl_check_namelen(struct path *path, struct ovl_fs *ofs, 
}



static int ovl_lower_dir(const char *name, struct path *path,

			 struct ovl_fs *ofs, int *stack_depth, bool *remote)

			 struct ovl_fs *ofs, int *stack_depth)

{

	int fh_type;

	int err;
@@ -794,9 +789,6 @@ static int ovl_lower_dir(const char *name, struct path *path, 


	*stack_depth = max(*stack_depth, path->mnt->mnt_sb->s_stack_depth);



	if (ovl_dentry_remote(path->dentry))

		*remote = true;



	/*

	 * The inodes index feature and NFS export need to encode and decode

	 * file handles, so they require that all layers support them.
@@ -1441,7 +1433,6 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb, 
	char *lowertmp, *lower;

	struct path *stack = NULL;

	unsigned int stacklen, numlower = 0, i;

	bool remote = false;

	struct ovl_entry *oe;



	err = -ENOMEM;
@@ -1473,7 +1464,7 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb, 
	lower = lowertmp;

	for (numlower = 0; numlower < stacklen; numlower++) {

		err = ovl_lower_dir(lower, &stack[numlower], ofs,

				    &sb->s_stack_depth, &remote);

				    &sb->s_stack_depth);

		if (err)

			goto out_err;
@@ -1501,11 +1492,6 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb, 
		oe->lowerstack[i].layer = &ofs->layers[i+1];

	}



	if (remote)

		sb->s_d_op = &ovl_reval_dentry_operations;

	else

		sb->s_d_op = &ovl_dentry_operations;



out:

	for (i = 0; i < numlower; i++)

		path_put(&stack[i]);
@@ -1623,6 +1609,7 @@ static struct dentry *ovl_get_root(struct super_block *sb, 
	ovl_dentry_set_flag(OVL_E_CONNECTED, root);

	ovl_set_upperdata(d_inode(root));

	ovl_inode_init(d_inode(root), &oip, ino, fsid);

	ovl_dentry_update_reval(root, upperdentry, DCACHE_OP_WEAK_REVALIDATE);



	return root;

}
@@ -1636,6 +1623,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) 
	struct cred *cred;

	int err;



	sb->s_d_op = &ovl_dentry_operations;



	err = -ENOMEM;

	ofs = kzalloc(sizeof(struct ovl_fs), GFP_KERNEL);

	if (!ofs)

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