Commit 2b21da92 authored by Amir Goldstein's avatar Amir Goldstein
Browse files

ovl: prepare to store lowerdata redirect for lazy lowerdata lookup 



Prepare to allow ovl_lookup() to leave the last entry in a non-dir
lowerstack empty to signify lazy lowerdata lookup.

In this case, ovl_lookup() stores the redirect path from metacopy to
lowerdata in ovl_inode, which is going to be used later to perform the
lazy lowerdata lookup.

Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 5436ab0a

fs/overlayfs/inode.c

+2 −0
Original line number Diff line number Diff line
@@ -1005,6 +1005,7 @@ void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip, 
	oi->__upperdentry = oip->upperdentry;

	oi->oe = oip->oe;

	oi->redirect = oip->redirect;

	oi->lowerdata_redirect = oip->lowerdata_redirect;



	realinode = ovl_inode_real(inode);

	ovl_copyattr(inode);
@@ -1365,6 +1366,7 @@ struct inode *ovl_get_inode(struct super_block *sb, 
			dput(upperdentry);

			ovl_free_entry(oip->oe);

			kfree(oip->redirect);

			kfree(oip->lowerdata_redirect);

			goto out;

		}

fs/overlayfs/namei.c

+5 −0
Original line number Diff line number Diff line
@@ -1183,6 +1183,11 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 
			.redirect = upperredirect,

		};



		/* Store lowerdata redirect for lazy lookup */

		if (ctr > 1 && !d.is_dir && !stack[ctr - 1].dentry) {

			oip.lowerdata_redirect = d.redirect;

			d.redirect = NULL;

		}

		inode = ovl_get_inode(dentry->d_sb, &oip);

		err = PTR_ERR(inode);

		if (IS_ERR(inode))

fs/overlayfs/overlayfs.h

+2 −0
Original line number Diff line number Diff line
@@ -405,6 +405,7 @@ struct inode *ovl_inode_lower(struct inode *inode); 
struct inode *ovl_inode_lowerdata(struct inode *inode);

struct inode *ovl_inode_real(struct inode *inode);

struct inode *ovl_inode_realdata(struct inode *inode);

const char *ovl_lowerdata_redirect(struct inode *inode);

struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);

void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);

void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry);
@@ -656,6 +657,7 @@ struct ovl_inode_params { 
	struct ovl_entry *oe;

	bool index;

	char *redirect;

	char *lowerdata_redirect;

};

void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip,

		    unsigned long ino, int fsid);

fs/overlayfs/ovl_entry.h

+2 −1
Original line number Diff line number Diff line
@@ -141,6 +141,7 @@ static inline struct ovl_path *ovl_lowerdata(struct ovl_entry *oe) 
	return lowerstack ? &lowerstack[oe->__numlower - 1] : NULL;

}



/* May return NULL if lazy lookup of lowerdata is needed */

static inline struct dentry *ovl_lowerdata_dentry(struct ovl_entry *oe)

{

	struct ovl_path *lowerdata = ovl_lowerdata(oe);
@@ -157,7 +158,7 @@ static inline unsigned long *OVL_E_FLAGS(struct dentry *dentry) 
struct ovl_inode {

	union {

		struct ovl_dir_cache *cache;	/* directory */

		/* place holder for non-dir */	/* regular file */

		const char *lowerdata_redirect;	/* regular file */

	};

	const char *redirect;

	u64 version;

fs/overlayfs/super.c

+3 −0
Original line number Diff line number Diff line
@@ -171,6 +171,7 @@ static struct inode *ovl_alloc_inode(struct super_block *sb) 
	oi->version = 0;

	oi->flags = 0;

	oi->__upperdentry = NULL;

	oi->lowerdata_redirect = NULL;

	oi->oe = NULL;

	mutex_init(&oi->lock);
@@ -194,6 +195,8 @@ static void ovl_destroy_inode(struct inode *inode) 
	ovl_free_entry(oi->oe);

	if (S_ISDIR(inode->i_mode))

		ovl_dir_cache_free(inode);

	else

		kfree(oi->lowerdata_redirect);

}



static void ovl_free_fs(struct ovl_fs *ofs)