Unverified Commit 92bf5357 authored by Jeff Layton's avatar Jeff Layton Committed by Christian Brauner
Browse files

vfs: make vfs_symlink break delegations on parent dir 



In order to add directory delegation support, we must break delegations
on the parent on any change to the directory.

Add a delegated_inode parameter to vfs_symlink() and have it break the
delegation. do_symlinkat() can then wait on the delegation break before
proceeding.

Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarNeilBrown <neil@brown.name>
Signed-off-by: default avatarJeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-12-52f3feebb2f2@kernel.org


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent e8960c1b

fs/ecryptfs/inode.c

+1 −1
Original line number Diff line number Diff line
@@ -479,7 +479,7 @@ static int ecryptfs_symlink(struct mnt_idmap *idmap, 
	if (rc)

		goto out_lock;

	rc = vfs_symlink(&nop_mnt_idmap, lower_dir, lower_dentry,

			 encoded_symname);

			 encoded_symname, NULL);

	kfree(encoded_symname);

	if (rc || d_really_is_negative(lower_dentry))

		goto out_lock;

fs/init.c

+1 −1
Original line number Diff line number Diff line
@@ -209,7 +209,7 @@ int __init init_symlink(const char *oldname, const char *newname) 
	error = security_path_symlink(&path, dentry, oldname);

	if (!error)

		error = vfs_symlink(mnt_idmap(path.mnt), path.dentry->d_inode,

				    dentry, oldname);

				    dentry, oldname, NULL);

	end_creating_path(&path, dentry);

	return error;

}

fs/namei.c

+14 −2
Original line number Diff line number Diff line
@@ -4845,6 +4845,7 @@ SYSCALL_DEFINE1(unlink, const char __user *, pathname) 
 * @dir:	inode of the parent directory

 * @dentry:	dentry of the child symlink file

 * @oldname:	name of the file to link to

 * @delegated_inode: returns victim inode, if the inode is delegated.

 *

 * Create a symlink.

 *
@@ -4855,7 +4856,8 @@ SYSCALL_DEFINE1(unlink, const char __user *, pathname) 
 * raw inode simply pass @nop_mnt_idmap.

 */

int vfs_symlink(struct mnt_idmap *idmap, struct inode *dir,

		struct dentry *dentry, const char *oldname)

		struct dentry *dentry, const char *oldname,

		struct delegated_inode *delegated_inode)

{

	int error;
@@ -4870,6 +4872,10 @@ int vfs_symlink(struct mnt_idmap *idmap, struct inode *dir, 
	if (error)

		return error;



	error = try_break_deleg(dir, delegated_inode);

	if (error)

		return error;



	error = dir->i_op->symlink(idmap, dir, dentry, oldname);

	if (!error)

		fsnotify_create(dir, dentry);
@@ -4883,6 +4889,7 @@ int do_symlinkat(struct filename *from, int newdfd, struct filename *to) 
	struct dentry *dentry;

	struct path path;

	unsigned int lookup_flags = 0;

	struct delegated_inode delegated_inode = { };



	if (IS_ERR(from)) {

		error = PTR_ERR(from);
@@ -4897,8 +4904,13 @@ int do_symlinkat(struct filename *from, int newdfd, struct filename *to) 
	error = security_path_symlink(&path, dentry, from->name);

	if (!error)

		error = vfs_symlink(mnt_idmap(path.mnt), path.dentry->d_inode,

				    dentry, from->name);

				    dentry, from->name, &delegated_inode);

	end_creating_path(&path, dentry);

	if (is_delegated(&delegated_inode)) {

		error = break_deleg_wait(&delegated_inode);

		if (!error)

			goto retry;

	}

	if (retry_estale(error, lookup_flags)) {

		lookup_flags |= LOOKUP_REVAL;

		goto retry;

fs/nfsd/vfs.c

+1 −1
Original line number Diff line number Diff line
@@ -1742,7 +1742,7 @@ nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, 
	err = fh_fill_pre_attrs(fhp);

	if (err != nfs_ok)

		goto out_unlock;

	host_err = vfs_symlink(&nop_mnt_idmap, d_inode(dentry), dnew, path);

	host_err = vfs_symlink(&nop_mnt_idmap, d_inode(dentry), dnew, path, NULL);

	err = nfserrno(host_err);

	cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);

	if (!err)

fs/overlayfs/overlayfs.h

+1 −1
Original line number Diff line number Diff line
@@ -267,7 +267,7 @@ static inline int ovl_do_symlink(struct ovl_fs *ofs, 
				 struct inode *dir, struct dentry *dentry,

				 const char *oldname)

{

	int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname);

	int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname, NULL);



	pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);

	return err;