Unverified Commit e8960c1b authored by Jeff Layton's avatar Jeff Layton Committed by Christian Brauner
Browse files

vfs: make vfs_mknod break delegations on parent directory 



In order to add directory delegation support, we need to break
delegations on the parent whenever there is going to be a change in the
directory.

Add a new delegated_inode pointer to vfs_mknod() and have the
appropriate callers wait when there is an outstanding delegation. All
other callers just set the pointer to NULL.

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-v6-11-52f3feebb2f2@kernel.org


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent c826229c

drivers/base/devtmpfs.c

+1 −1
Original line number Diff line number Diff line
@@ -231,7 +231,7 @@ static int handle_create(const char *nodename, umode_t mode, kuid_t uid, 
		return PTR_ERR(dentry);



	err = vfs_mknod(&nop_mnt_idmap, d_inode(path.dentry), dentry, mode,

			dev->devt);

			dev->devt, NULL);

	if (!err) {

		struct iattr newattrs;

fs/ecryptfs/inode.c

+1 −1
Original line number Diff line number Diff line
@@ -564,7 +564,7 @@ ecryptfs_mknod(struct mnt_idmap *idmap, struct inode *dir, 
	rc = lock_parent(dentry, &lower_dentry, &lower_dir);

	if (!rc)

		rc = vfs_mknod(&nop_mnt_idmap, lower_dir,

			       lower_dentry, mode, dev);

			       lower_dentry, mode, dev, NULL);

	if (rc || d_really_is_negative(lower_dentry))

		goto out;

	rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);

fs/init.c

+1 −1
Original line number Diff line number Diff line
@@ -157,7 +157,7 @@ int __init init_mknod(const char *filename, umode_t mode, unsigned int dev) 
	error = security_path_mknod(&path, dentry, mode, dev);

	if (!error)

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

				  dentry, mode, new_decode_dev(dev));

				  dentry, mode, new_decode_dev(dev), NULL);

	end_creating_path(&path, dentry);

	return error;

}

fs/namei.c

+15 −8
Original line number Diff line number Diff line
@@ -4295,6 +4295,7 @@ inline struct dentry *start_creating_user_path( 
}

EXPORT_SYMBOL(start_creating_user_path);





/**

 * vfs_mknod - create device node or file

 * @idmap:		idmap of the mount the inode was found from
@@ -4302,6 +4303,7 @@ EXPORT_SYMBOL(start_creating_user_path); 
 * @dentry:		dentry of the child device node

 * @mode:		mode of the child device node

 * @dev:		device number of device to create

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

 *

 * Create a device node or file.

 *
@@ -4312,7 +4314,8 @@ EXPORT_SYMBOL(start_creating_user_path); 
 * raw inode simply pass @nop_mnt_idmap.

 */

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

	      struct dentry *dentry, umode_t mode, dev_t dev)

	      struct dentry *dentry, umode_t mode, dev_t dev,

	      struct delegated_inode *delegated_inode)

{

	bool is_whiteout = S_ISCHR(mode) && dev == WHITEOUT_DEV;

	int error = may_create(idmap, dir, dentry);
@@ -4336,6 +4339,10 @@ int vfs_mknod(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->mknod(idmap, dir, dentry, mode, dev);

	if (!error)

		fsnotify_create(dir, dentry);
@@ -4393,11 +4400,11 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode, 
			break;

		case S_IFCHR: case S_IFBLK:

			error = vfs_mknod(idmap, path.dentry->d_inode,

					  dentry, mode, new_decode_dev(dev));

					  dentry, mode, new_decode_dev(dev), &di);

			break;

		case S_IFIFO: case S_IFSOCK:

			error = vfs_mknod(idmap, path.dentry->d_inode,

					  dentry, mode, 0);

					  dentry, mode, 0, &di);

			break;

	}

out2:

fs/nfsd/vfs.c

+1 −1
Original line number Diff line number Diff line
@@ -1573,7 +1573,7 @@ nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp, 
	case S_IFIFO:

	case S_IFSOCK:

		host_err = vfs_mknod(&nop_mnt_idmap, dirp, dchild,

				     iap->ia_mode, rdev);

				     iap->ia_mode, rdev, NULL);

		break;

	default:

		printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",