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Commit 58ed4e70 authored by Andreas Gruenbacher's avatar Andreas Gruenbacher Committed by Miklos Szeredi
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ovl: store ovl_entry in inode->i_private for all inodes 



Previously this was only done for directory inodes.  Doing so for all
inodes makes for a nice cleanup in ovl_permission at zero cost.

Inodes are not shared for hard links on the overlay, so this works fine.

Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent eead4f2d

fs/overlayfs/inode.c

+11 −37
Original line number Diff line number Diff line
@@ -109,31 +109,12 @@ static int ovl_getattr(struct vfsmount *mnt, struct dentry *dentry, 


int ovl_permission(struct inode *inode, int mask)

{

	struct ovl_entry *oe;

	struct dentry *alias = NULL;

	struct inode *realinode;

	struct dentry *realdentry;

	struct ovl_entry *oe = inode->i_private;

	bool is_upper;

	struct dentry *realdentry = ovl_entry_real(oe, &is_upper);

	struct inode *realinode;

	int err;



	if (S_ISDIR(inode->i_mode)) {

		oe = inode->i_private;

	} else if (mask & MAY_NOT_BLOCK) {

		return -ECHILD;

	} else {

		/*

		 * For non-directories find an alias and get the info

		 * from there.

		 */

		alias = d_find_any_alias(inode);

		if (WARN_ON(!alias))

			return -ENOENT;



		oe = alias->d_fsdata;

	}



	realdentry = ovl_entry_real(oe, &is_upper);



	if (ovl_is_default_permissions(inode)) {

		struct kstat stat;

		struct path realpath = { .dentry = realdentry };
@@ -145,26 +126,23 @@ int ovl_permission(struct inode *inode, int mask) 


		err = vfs_getattr(&realpath, &stat);

		if (err)

			goto out_dput;

			return err;



		err = -ESTALE;

		if ((stat.mode ^ inode->i_mode) & S_IFMT)

			goto out_dput;

			return -ESTALE;



		inode->i_mode = stat.mode;

		inode->i_uid = stat.uid;

		inode->i_gid = stat.gid;



		err = generic_permission(inode, mask);

		goto out_dput;

		return generic_permission(inode, mask);

	}



	/* Careful in RCU walk mode */

	realinode = ACCESS_ONCE(realdentry->d_inode);

	realinode = d_inode_rcu(realdentry);

	if (!realinode) {

		WARN_ON(!(mask & MAY_NOT_BLOCK));

		err = -ENOENT;

		goto out_dput;

		return -ENOENT;

	}



	if (mask & MAY_WRITE) {
@@ -183,16 +161,12 @@ int ovl_permission(struct inode *inode, int mask) 
		 * constructed return EROFS to prevent modification of

		 * upper layer.

		 */

		err = -EROFS;

		if (is_upper && !IS_RDONLY(inode) && IS_RDONLY(realinode) &&

		    (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))

			goto out_dput;

			return -EROFS;

	}



	err = __inode_permission(realinode, mask);

out_dput:

	dput(alias);

	return err;

	return __inode_permission(realinode, mask);

}



static const char *ovl_get_link(struct dentry *dentry,
@@ -405,11 +379,11 @@ struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, 
	inode->i_ino = get_next_ino();

	inode->i_mode = mode;

	inode->i_flags |= S_NOATIME | S_NOCMTIME;

	inode->i_private = oe;



	mode &= S_IFMT;

	switch (mode) {

	case S_IFDIR:

		inode->i_private = oe;

		inode->i_op = &ovl_dir_inode_operations;

		inode->i_fop = &ovl_dir_operations;

		break;