Commit 2664bd08 authored by Vivek Goyal's avatar Vivek Goyal Committed by Miklos Szeredi
Browse files

ovl: Store lower data inode in ovl_inode 



Right now ovl_inode stores inode pointer for lower inode.  This helps with
quickly getting lower inode given overlay inode (ovl_inode_lower()).

Now with metadata only copy-up, we can have metacopy inode in middle layer
as well and inode containing data can be different from ->lower.  I need to
be able to open the real file in ovl_open_realfile() and for that I need to
quickly find the lower data inode.

Hence store lower data inode also in ovl_inode.  Also provide an helper
ovl_inode_lowerdata() to access this field.

Signed-off-by: default avatarVivek Goyal <vgoyal@redhat.com>
Reviewed-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 67d756c2

fs/overlayfs/inode.c

+1 −1
Original line number Diff line number Diff line
@@ -864,7 +864,7 @@ struct inode *ovl_get_inode(struct super_block *sb, 
		}

	}

	ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev, ino, fsid);

	ovl_inode_init(inode, upperdentry, lowerdentry);

	ovl_inode_init(inode, upperdentry, lowerdentry, oip->lowerdata);



	if (upperdentry && ovl_is_impuredir(upperdentry))

		ovl_set_flag(OVL_IMPURE, inode);

fs/overlayfs/namei.c

+2 −0
Original line number Diff line number Diff line
@@ -1080,6 +1080,8 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 
			.index = index,

			.numlower = ctr,

			.redirect = upperredirect,

			.lowerdata = (ctr > 1 && !d.is_dir) ?

				      stack[ctr - 1].dentry : NULL,

		};



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

fs/overlayfs/overlayfs.h

+3 −1
Original line number Diff line number Diff line
@@ -227,6 +227,7 @@ struct dentry *ovl_dentry_real(struct dentry *dentry); 
struct dentry *ovl_i_dentry_upper(struct inode *inode);

struct inode *ovl_inode_upper(struct inode *inode);

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 ovl_dir_cache *ovl_dir_cache(struct inode *inode);

void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
@@ -246,7 +247,7 @@ bool ovl_redirect_dir(struct super_block *sb); 
const char *ovl_dentry_get_redirect(struct dentry *dentry);

void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);

void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,

		    struct dentry *lowerdentry);

		    struct dentry *lowerdentry, struct dentry *lowerdata);

void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);

void ovl_dir_modified(struct dentry *dentry, bool impurity);

u64 ovl_dentry_version_get(struct dentry *dentry);
@@ -354,6 +355,7 @@ struct ovl_inode_params { 
	struct dentry *index;

	unsigned int numlower;

	char *redirect;

	struct dentry *lowerdata;

};

struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);

struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,

fs/overlayfs/ovl_entry.h

+4 −1
Original line number Diff line number Diff line
@@ -89,7 +89,10 @@ static inline struct ovl_entry *OVL_E(struct dentry *dentry) 
}



struct ovl_inode {

	struct ovl_dir_cache *cache;

	union {

		struct ovl_dir_cache *cache;	/* directory */

		struct inode *lowerdata;	/* regular file */

	};

	const char *redirect;

	u64 version;

	unsigned long flags;

fs/overlayfs/super.c

+6 −2
Original line number Diff line number Diff line
@@ -181,6 +181,7 @@ static struct inode *ovl_alloc_inode(struct super_block *sb) 
	oi->flags = 0;

	oi->__upperdentry = NULL;

	oi->lower = NULL;

	oi->lowerdata = NULL;

	mutex_init(&oi->lock);



	return &oi->vfs_inode;
@@ -199,8 +200,11 @@ static void ovl_destroy_inode(struct inode *inode) 


	dput(oi->__upperdentry);

	iput(oi->lower);

	kfree(oi->redirect);

	if (S_ISDIR(inode->i_mode))

		ovl_dir_cache_free(inode);

	else

		iput(oi->lowerdata);

	kfree(oi->redirect);

	mutex_destroy(&oi->lock);



	call_rcu(&inode->i_rcu, ovl_i_callback);
@@ -1487,7 +1491,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) 
	ovl_dentry_set_flag(OVL_E_CONNECTED, root_dentry);

	ovl_set_upperdata(d_inode(root_dentry));

	ovl_inode_init(d_inode(root_dentry), upperpath.dentry,

		       ovl_dentry_lower(root_dentry));

		       ovl_dentry_lower(root_dentry), NULL);



	sb->s_root = root_dentry;

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