Commit 32a3d848 authored by Al Viro's avatar Al Viro Committed by Miklos Szeredi
Browse files

ovl: clean up kstat usage 



FWIW, there's a bit of abuse of struct kstat in overlayfs object
creation paths - for one thing, it ends up with a very small subset
of struct kstat (mode + rdev), for another it also needs link in
case of symlinks and ends up passing it separately.

IMO it would be better to introduce a separate object for that.

In principle, we might even lift that thing into general API and switch
 ->mkdir()/->mknod()/->symlink() to identical calling conventions.  Hell
knows, perhaps ->create() as well...

Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 9aba6521

fs/overlayfs/copy_up.c

+7 −5
Original line number Diff line number Diff line
@@ -238,10 +238,15 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir, 
	struct inode *udir = upperdir->d_inode;

	struct dentry *newdentry = NULL;

	struct dentry *upper = NULL;

	umode_t mode = stat->mode;

	int err;

	const struct cred *old_creds = NULL;

	struct cred *new_creds = NULL;

	struct cattr cattr = {

		/* Can't properly set mode on creation because of the umask */

		.mode = stat->mode & S_IFMT,

		.rdev = stat->rdev,

		.link = link

	};



	newdentry = ovl_lookup_temp(workdir, dentry);

	err = PTR_ERR(newdentry);
@@ -261,10 +266,7 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir, 
	if (new_creds)

		old_creds = override_creds(new_creds);



	/* Can't properly set mode on creation because of the umask */

	stat->mode &= S_IFMT;

	err = ovl_create_real(wdir, newdentry, stat, link, NULL, true);

	stat->mode = mode;

	err = ovl_create_real(wdir, newdentry, &cattr, NULL, true);



	if (new_creds) {

		revert_creds(old_creds);

fs/overlayfs/dir.c

+28 −28
Original line number Diff line number Diff line
@@ -82,8 +82,7 @@ static struct dentry *ovl_whiteout(struct dentry *workdir, 
}



int ovl_create_real(struct inode *dir, struct dentry *newdentry,

		    struct kstat *stat, const char *link,

		    struct dentry *hardlink, bool debug)

		    struct cattr *attr, struct dentry *hardlink, bool debug)

{

	int err;
@@ -93,13 +92,13 @@ int ovl_create_real(struct inode *dir, struct dentry *newdentry, 
	if (hardlink) {

		err = ovl_do_link(hardlink, dir, newdentry, debug);

	} else {

		switch (stat->mode & S_IFMT) {

		switch (attr->mode & S_IFMT) {

		case S_IFREG:

			err = ovl_do_create(dir, newdentry, stat->mode, debug);

			err = ovl_do_create(dir, newdentry, attr->mode, debug);

			break;



		case S_IFDIR:

			err = ovl_do_mkdir(dir, newdentry, stat->mode, debug);

			err = ovl_do_mkdir(dir, newdentry, attr->mode, debug);

			break;



		case S_IFCHR:
@@ -107,11 +106,11 @@ int ovl_create_real(struct inode *dir, struct dentry *newdentry, 
		case S_IFIFO:

		case S_IFSOCK:

			err = ovl_do_mknod(dir, newdentry,

					   stat->mode, stat->rdev, debug);

					   attr->mode, attr->rdev, debug);

			break;



		case S_IFLNK:

			err = ovl_do_symlink(dir, newdentry, link, debug);

			err = ovl_do_symlink(dir, newdentry, attr->link, debug);

			break;



		default:
@@ -190,8 +189,7 @@ static bool ovl_type_merge(struct dentry *dentry) 
}



static int ovl_create_upper(struct dentry *dentry, struct inode *inode,

			    struct kstat *stat, const char *link,

			    struct dentry *hardlink)

			    struct cattr *attr, struct dentry *hardlink)

{

	struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);

	struct inode *udir = upperdir->d_inode;
@@ -199,7 +197,7 @@ static int ovl_create_upper(struct dentry *dentry, struct inode *inode, 
	int err;



	if (!hardlink && !IS_POSIXACL(udir))

		stat->mode &= ~current_umask();

		attr->mode &= ~current_umask();



	inode_lock_nested(udir, I_MUTEX_PARENT);

	newdentry = lookup_one_len(dentry->d_name.name, upperdir,
@@ -207,7 +205,7 @@ static int ovl_create_upper(struct dentry *dentry, struct inode *inode, 
	err = PTR_ERR(newdentry);

	if (IS_ERR(newdentry))

		goto out_unlock;

	err = ovl_create_real(udir, newdentry, stat, link, hardlink, false);

	err = ovl_create_real(udir, newdentry, attr, hardlink, false);

	if (err)

		goto out_dput;
@@ -282,7 +280,8 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry, 
	if (IS_ERR(opaquedir))

		goto out_unlock;



	err = ovl_create_real(wdir, opaquedir, &stat, NULL, NULL, true);

	err = ovl_create_real(wdir, opaquedir,

			      &(struct cattr){.mode = stat.mode}, NULL, true);

	if (err)

		goto out_dput;
@@ -382,7 +381,7 @@ out_free: 
}



static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,

				    struct kstat *stat, const char *link,

				    struct cattr *cattr,

				    struct dentry *hardlink)

{

	struct dentry *workdir = ovl_workdir(dentry);
@@ -399,7 +398,7 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, 


	if (!hardlink) {

		err = posix_acl_create(dentry->d_parent->d_inode,

				       &stat->mode, &default_acl, &acl);

				       &cattr->mode, &default_acl, &acl);

		if (err)

			return err;

	}
@@ -419,7 +418,7 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, 
	if (IS_ERR(upper))

		goto out_dput;



	err = ovl_create_real(wdir, newdentry, stat, link, hardlink, true);

	err = ovl_create_real(wdir, newdentry, cattr, hardlink, true);

	if (err)

		goto out_dput2;
@@ -427,10 +426,11 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, 
	 * mode could have been mutilated due to umask (e.g. sgid directory)

	 */

	if (!hardlink &&

	    !S_ISLNK(stat->mode) && newdentry->d_inode->i_mode != stat->mode) {

	    !S_ISLNK(cattr->mode) &&

	    newdentry->d_inode->i_mode != cattr->mode) {

		struct iattr attr = {

			.ia_valid = ATTR_MODE,

			.ia_mode = stat->mode,

			.ia_mode = cattr->mode,

		};

		inode_lock(newdentry->d_inode);

		err = notify_change(newdentry, &attr, NULL);
@@ -450,7 +450,7 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, 
			goto out_cleanup;

	}



	if (!hardlink && S_ISDIR(stat->mode)) {

	if (!hardlink && S_ISDIR(cattr->mode)) {

		err = ovl_set_opaque(dentry, newdentry);

		if (err)

			goto out_cleanup;
@@ -487,8 +487,7 @@ out_cleanup: 
}



static int ovl_create_or_link(struct dentry *dentry, struct inode *inode,

			      struct kstat *stat, const char *link,

			      struct dentry *hardlink)

			      struct cattr *attr, struct dentry *hardlink)

{

	int err;

	const struct cred *old_cred;
@@ -506,7 +505,7 @@ static int ovl_create_or_link(struct dentry *dentry, struct inode *inode, 
		override_cred->fsgid = inode->i_gid;

		if (!hardlink) {

			err = security_dentry_create_files_as(dentry,

					stat->mode, &dentry->d_name, old_cred,

					attr->mode, &dentry->d_name, old_cred,

					override_cred);

			if (err) {

				put_cred(override_cred);
@@ -517,11 +516,11 @@ static int ovl_create_or_link(struct dentry *dentry, struct inode *inode, 
		put_cred(override_cred);



		if (!ovl_dentry_is_whiteout(dentry))

			err = ovl_create_upper(dentry, inode, stat, link,

			err = ovl_create_upper(dentry, inode, attr,

						hardlink);

		else

			err = ovl_create_over_whiteout(dentry, inode, stat,

							link, hardlink);

			err = ovl_create_over_whiteout(dentry, inode, attr,

							hardlink);

	}

out_revert_creds:

	revert_creds(old_cred);
@@ -540,8 +539,9 @@ static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev, 
{

	int err;

	struct inode *inode;

	struct kstat stat = {

	struct cattr attr = {

		.rdev = rdev,

		.link = link,

	};



	err = ovl_want_write(dentry);
@@ -554,9 +554,9 @@ static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev, 
		goto out_drop_write;



	inode_init_owner(inode, dentry->d_parent->d_inode, mode);

	stat.mode = inode->i_mode;

	attr.mode = inode->i_mode;



	err = ovl_create_or_link(dentry, inode, &stat, link, NULL);

	err = ovl_create_or_link(dentry, inode, &attr, NULL);

	if (err)

		iput(inode);
@@ -610,7 +610,7 @@ static int ovl_link(struct dentry *old, struct inode *newdir, 
	inode = d_inode(old);

	ihold(inode);



	err = ovl_create_or_link(new, inode, NULL, NULL, ovl_dentry_upper(old));

	err = ovl_create_or_link(new, inode, NULL, ovl_dentry_upper(old));

	if (err)

		iput(inode);

fs/overlayfs/overlayfs.h

+6 −1
Original line number Diff line number Diff line
@@ -212,8 +212,13 @@ static inline void ovl_copyattr(struct inode *from, struct inode *to) 
/* dir.c */

extern const struct inode_operations ovl_dir_inode_operations;

struct dentry *ovl_lookup_temp(struct dentry *workdir, struct dentry *dentry);

struct cattr {

	dev_t rdev;

	umode_t mode;

	const char *link;

};

int ovl_create_real(struct inode *dir, struct dentry *newdentry,

		    struct kstat *stat, const char *link,

		    struct cattr *attr,

		    struct dentry *hardlink, bool debug);

void ovl_cleanup(struct inode *dir, struct dentry *dentry);

fs/overlayfs/super.c

+4 −5
Original line number Diff line number Diff line
@@ -354,12 +354,9 @@ retry: 
			      strlen(OVL_WORKDIR_NAME));



	if (!IS_ERR(work)) {

		struct kstat stat = {

			.mode = S_IFDIR | 0,

		};

		struct iattr attr = {

			.ia_valid = ATTR_MODE,

			.ia_mode = stat.mode,

			.ia_mode = S_IFDIR | 0,

		};



		if (work->d_inode) {
@@ -373,7 +370,9 @@ retry: 
			goto retry;

		}



		err = ovl_create_real(dir, work, &stat, NULL, NULL, true);

		err = ovl_create_real(dir, work,

				      &(struct cattr){.mode = S_IFDIR | 0},

				      NULL, true);

		if (err)

			goto out_dput;

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