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Commit 9678e630 authored by Amir Goldstein's avatar Amir Goldstein Committed by Miklos Szeredi
Browse files

ovl: fix inconsistent d_ino for legacy merge dir 



For a merge dir that was copied up before v4.12 or that was hand crafted
offline (e.g. mkdir {upper/lower}/dir), upper dir does not contain the
'trusted.overlay.origin' xattr.  In that case, stat(2) on the merge dir
returns the lower dir st_ino, but getdents(2) returns the upper dir d_ino.

After this change, on merge dir lookup, missing origin xattr on upper
dir will be fixed and 'impure' xattr will be fixed on parent of the legacy
merge dir.

Suggested-by: default avatarzhangyi (F) <yi.zhang@huawei.com>
Reviewed-by: default avatarzhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent a5a927a7

fs/overlayfs/copy_up.c

+2 −2
Original line number Diff line number Diff line
@@ -288,7 +288,7 @@ struct ovl_fh *ovl_encode_fh(struct dentry *lower, bool is_upper) 
	return fh;

}



static int ovl_set_origin(struct dentry *dentry, struct dentry *lower,

int ovl_set_origin(struct dentry *dentry, struct dentry *lower,

		   struct dentry *upper)

{

	const struct ovl_fh *fh = NULL;

fs/overlayfs/namei.c

+33 −0
Original line number Diff line number Diff line
@@ -584,6 +584,27 @@ static int ovl_find_layer(struct ovl_fs *ofs, struct ovl_path *path) 
	return i;

}



/* Fix missing 'origin' xattr */

static int ovl_fix_origin(struct dentry *dentry, struct dentry *lower,

			  struct dentry *upper)

{

	int err;



	if (ovl_check_origin_xattr(upper))

		return 0;



	err = ovl_want_write(dentry);

	if (err)

		return err;



	err = ovl_set_origin(dentry, lower, upper);

	if (!err)

		err = ovl_set_impure(dentry->d_parent, upper->d_parent);



	ovl_drop_write(dentry);

	return err;

}



struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,

			  unsigned int flags)

{
@@ -674,6 +695,18 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 
		if (!this)

			continue;



		/*

		 * If no origin fh is stored in upper of a merge dir, store fh

		 * of lower dir and set upper parent "impure".

		 */

		if (upperdentry && !ctr && !ofs->noxattr) {

			err = ovl_fix_origin(dentry, this, upperdentry);

			if (err) {

				dput(this);

				goto out_put;

			}

		}



		stack[ctr].dentry = this;

		stack[ctr].layer = lower.layer;

		ctr++;

fs/overlayfs/overlayfs.h

+2 −0
Original line number Diff line number Diff line
@@ -322,3 +322,5 @@ int ovl_copy_up_flags(struct dentry *dentry, int flags); 
int ovl_copy_xattr(struct dentry *old, struct dentry *new);

int ovl_set_attr(struct dentry *upper, struct kstat *stat);

struct ovl_fh *ovl_encode_fh(struct dentry *lower, bool is_upper);

int ovl_set_origin(struct dentry *dentry, struct dentry *lower,

		   struct dentry *upper);