Commit 22f289ce authored by Christian Brauner's avatar Christian Brauner Committed by Miklos Szeredi
Browse files

ovl: use ovl_lookup_upper() wrapper 



Introduce ovl_lookup_upper() as a simple wrapper around lookup_one().
Make it clear in the helper's name that this only operates on the upper
layer. The wrapper will take upper layer's idmapping into account when
checking permission in lookup_one().

Cc: <linux-unionfs@vger.kernel.org>
Tested-by: default avatarGiuseppe Scrivano <gscrivan@redhat.com>
Reviewed-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarChristian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent a15506ea

fs/overlayfs/copy_up.c

+7 −5
Original line number Diff line number Diff line
@@ -486,7 +486,7 @@ static int ovl_create_index(struct dentry *dentry, struct dentry *origin, 
	if (err)

		goto out;



	index = lookup_one_len(name.name, indexdir, name.len);

	index = ovl_lookup_upper(ofs, name.name, indexdir, name.len);

	if (IS_ERR(index)) {

		err = PTR_ERR(index);

	} else {
@@ -535,7 +535,7 @@ static int ovl_link_up(struct ovl_copy_up_ctx *c) 
		return err;



	inode_lock_nested(udir, I_MUTEX_PARENT);

	upper = lookup_one_len(c->dentry->d_name.name, upperdir,

	upper = ovl_lookup_upper(ofs, c->dentry->d_name.name, upperdir,

				 c->dentry->d_name.len);

	err = PTR_ERR(upper);

	if (!IS_ERR(upper)) {
@@ -699,7 +699,8 @@ static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c) 
			goto cleanup;

	}



	upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len);

	upper = ovl_lookup_upper(ofs, c->destname.name, c->destdir,

				 c->destname.len);

	err = PTR_ERR(upper);

	if (IS_ERR(upper))

		goto cleanup;
@@ -751,7 +752,8 @@ static int ovl_copy_up_tmpfile(struct ovl_copy_up_ctx *c) 


	inode_lock_nested(udir, I_MUTEX_PARENT);



	upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len);

	upper = ovl_lookup_upper(ofs, c->destname.name, c->destdir,

				 c->destname.len);

	err = PTR_ERR(upper);

	if (!IS_ERR(upper)) {

		err = ovl_do_link(ofs, temp, udir, upper);

fs/overlayfs/dir.c

+15 −16
Original line number Diff line number Diff line
@@ -51,7 +51,7 @@ struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir) 
	/* counter is allowed to wrap, since temp dentries are ephemeral */

	snprintf(name, sizeof(name), "#%x", atomic_inc_return(&temp_id));



	temp = lookup_one_len(name, workdir, strlen(name));

	temp = ovl_lookup_upper(ofs, name, workdir, strlen(name));

	if (!IS_ERR(temp) && temp->d_inode) {

		pr_err("workdir/%s already exists\n", name);

		dput(temp);
@@ -155,7 +155,7 @@ int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir, 
	 * to it unhashed and negative. If that happens, try to

	 * lookup a new hashed and positive dentry.

	 */

	d = lookup_one_len(dentry->d_name.name, dentry->d_parent,

	d = ovl_lookup_upper(ofs, dentry->d_name.name, dentry->d_parent,

			     dentry->d_name.len);

	if (IS_ERR(d)) {

		pr_warn("failed lookup after mkdir (%pd2, err=%i).\n",
@@ -333,9 +333,8 @@ static int ovl_create_upper(struct dentry *dentry, struct inode *inode, 


	inode_lock_nested(udir, I_MUTEX_PARENT);

	newdentry = ovl_create_real(ofs, udir,

				    lookup_one_len(dentry->d_name.name,

						   upperdir,

						   dentry->d_name.len),

				    ovl_lookup_upper(ofs, dentry->d_name.name,

						     upperdir, dentry->d_name.len),

				    attr);

	err = PTR_ERR(newdentry);

	if (IS_ERR(newdentry))
@@ -488,7 +487,7 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, 
	if (err)

		goto out;



	upper = lookup_one_len(dentry->d_name.name, upperdir,

	upper = ovl_lookup_upper(ofs, dentry->d_name.name, upperdir,

				 dentry->d_name.len);

	err = PTR_ERR(upper);

	if (IS_ERR(upper))
@@ -771,7 +770,7 @@ static int ovl_remove_and_whiteout(struct dentry *dentry, 
	if (err)

		goto out_dput;



	upper = lookup_one_len(dentry->d_name.name, upperdir,

	upper = ovl_lookup_upper(ofs, dentry->d_name.name, upperdir,

				 dentry->d_name.len);

	err = PTR_ERR(upper);

	if (IS_ERR(upper))
@@ -819,7 +818,7 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir, 
	}



	inode_lock_nested(dir, I_MUTEX_PARENT);

	upper = lookup_one_len(dentry->d_name.name, upperdir,

	upper = ovl_lookup_upper(ofs, dentry->d_name.name, upperdir,

				 dentry->d_name.len);

	err = PTR_ERR(upper);

	if (IS_ERR(upper))
@@ -1195,7 +1194,7 @@ static int ovl_rename(struct user_namespace *mnt_userns, struct inode *olddir, 


	trap = lock_rename(new_upperdir, old_upperdir);



	olddentry = lookup_one_len(old->d_name.name, old_upperdir,

	olddentry = ovl_lookup_upper(ofs, old->d_name.name, old_upperdir,

				     old->d_name.len);

	err = PTR_ERR(olddentry);

	if (IS_ERR(olddentry))
@@ -1205,7 +1204,7 @@ static int ovl_rename(struct user_namespace *mnt_userns, struct inode *olddir, 
	if (!ovl_matches_upper(old, olddentry))

		goto out_dput_old;



	newdentry = lookup_one_len(new->d_name.name, new_upperdir,

	newdentry = ovl_lookup_upper(ofs, new->d_name.name, new_upperdir,

				     new->d_name.len);

	err = PTR_ERR(newdentry);

	if (IS_ERR(newdentry))

fs/overlayfs/overlayfs.h

+8 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#include <linux/kernel.h>

#include <linux/uuid.h>

#include <linux/fs.h>

#include <linux/namei.h>

#include "ovl_entry.h"



#undef pr_fmt
@@ -310,6 +311,13 @@ static inline struct dentry *ovl_do_tmpfile(struct ovl_fs *ofs, 
	return ret;

}



static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs,

					      const char *name,

					      struct dentry *base, int len)

{

	return lookup_one(ovl_upper_mnt_userns(ofs), name, base, len);

}



static inline bool ovl_open_flags_need_copy_up(int flags)

{

	if (!flags)

fs/overlayfs/readdir.c

+3 −3
Original line number Diff line number Diff line
@@ -1013,7 +1013,7 @@ void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper, 
		if (WARN_ON(!p->is_whiteout || !p->is_upper))

			continue;



		dentry = lookup_one_len(p->name, upper, p->len);

		dentry = ovl_lookup_upper(ofs, p->name, upper, p->len);

		if (IS_ERR(dentry)) {

			pr_err("lookup '%s/%.*s' failed (%i)\n",

			       upper->d_name.name, p->len, p->name,
@@ -1113,7 +1113,7 @@ static int ovl_workdir_cleanup_recurse(struct ovl_fs *ofs, struct path *path, 
			err = -EINVAL;

			break;

		}

		dentry = lookup_one_len(p->name, path->dentry, p->len);

		dentry = ovl_lookup_upper(ofs, p->name, path->dentry, p->len);

		if (IS_ERR(dentry))

			continue;

		if (dentry->d_inode)
@@ -1181,7 +1181,7 @@ int ovl_indexdir_cleanup(struct ovl_fs *ofs) 
			if (p->len == 2 && p->name[1] == '.')

				continue;

		}

		index = lookup_one_len(p->name, indexdir, p->len);

		index = ovl_lookup_upper(ofs, p->name, indexdir, p->len);

		if (IS_ERR(index)) {

			err = PTR_ERR(index);

			index = NULL;

fs/overlayfs/super.c

+3 −3
Original line number Diff line number Diff line
@@ -761,7 +761,7 @@ static struct dentry *ovl_workdir_create(struct ovl_fs *ofs, 


	inode_lock_nested(dir, I_MUTEX_PARENT);

retry:

	work = lookup_one_len(name, ofs->workbasedir, strlen(name));

	work = ovl_lookup_upper(ofs, name, ofs->workbasedir, strlen(name));



	if (!IS_ERR(work)) {

		struct iattr attr = {
@@ -1289,7 +1289,7 @@ static int ovl_check_rename_whiteout(struct ovl_fs *ofs) 
		goto cleanup_temp;

	}



	whiteout = lookup_one_len(name.name.name, workdir, name.name.len);

	whiteout = ovl_lookup_upper(ofs, name.name.name, workdir, name.name.len);

	err = PTR_ERR(whiteout);

	if (IS_ERR(whiteout))

		goto cleanup_temp;
@@ -1321,7 +1321,7 @@ static struct dentry *ovl_lookup_or_create(struct ovl_fs *ofs, 
	struct dentry *child;



	inode_lock_nested(parent->d_inode, I_MUTEX_PARENT);

	child = lookup_one_len(name, parent, len);

	child = ovl_lookup_upper(ofs, name, parent, len);

	if (!IS_ERR(child) && !child->d_inode)

		child = ovl_create_real(ofs, parent->d_inode, child,

					OVL_CATTR(mode));