Unverified Commit d701902c authored by NeilBrown's avatar NeilBrown Committed by Christian Brauner
Browse files

fuse: return correct dentry for ->mkdir 



fuse already uses d_splice_alias() to ensure an appropriate dentry is
found for a newly created dentry.  Now that ->mkdir can return that
dentry we do so.

This requires changing create_new_entry() to return a dentry and
handling that change in all callers.

Note that when create_new_entry() is asked to create anything other than
a directory we can be sure it will NOT return an alternate dentry as
d_splice_alias() only returns an alternate dentry for directories.
So we don't need to check for that case when passing one the result.

Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/174112490070.33508.15852253149143067890@noble.neil.brown.name


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 3f92c7b5

fs/fuse/dir.c

+31 −17
Original line number Diff line number Diff line
@@ -781,7 +781,7 @@ static int fuse_atomic_open(struct inode *dir, struct dentry *entry, 
/*

 * Code shared between mknod, mkdir, symlink and link

 */

static int create_new_entry(struct mnt_idmap *idmap, struct fuse_mount *fm,

static struct dentry *create_new_entry(struct mnt_idmap *idmap, struct fuse_mount *fm,

				       struct fuse_args *args, struct inode *dir,

				       struct dentry *entry, umode_t mode)

{
@@ -792,11 +792,11 @@ static int create_new_entry(struct mnt_idmap *idmap, struct fuse_mount *fm, 
	struct fuse_forget_link *forget;



	if (fuse_is_bad(dir))

		return -EIO;

		return ERR_PTR(-EIO);



	forget = fuse_alloc_forget();

	if (!forget)

		return -ENOMEM;

		return ERR_PTR(-ENOMEM);



	memset(&outarg, 0, sizeof(outarg));

	args->nodeid = get_node_id(dir);
@@ -826,29 +826,43 @@ static int create_new_entry(struct mnt_idmap *idmap, struct fuse_mount *fm, 
			  &outarg.attr, ATTR_TIMEOUT(&outarg), 0, 0);

	if (!inode) {

		fuse_queue_forget(fm->fc, forget, outarg.nodeid, 1);

		return -ENOMEM;

		return ERR_PTR(-ENOMEM);

	}

	kfree(forget);



	d_drop(entry);

	d = d_splice_alias(inode, entry);

	if (IS_ERR(d))

		return PTR_ERR(d);

		return d;



	if (d) {

	if (d)

		fuse_change_entry_timeout(d, &outarg);

		dput(d);

	} else {

	else

		fuse_change_entry_timeout(entry, &outarg);

	}

	fuse_dir_changed(dir);

	return 0;

	return d;



 out_put_forget_req:

	if (err == -EEXIST)

		fuse_invalidate_entry(entry);

	kfree(forget);

	return err;

	return ERR_PTR(err);

}



static int create_new_nondir(struct mnt_idmap *idmap, struct fuse_mount *fm,

			     struct fuse_args *args, struct inode *dir,

			     struct dentry *entry, umode_t mode)

{

	/*

	 * Note that when creating anything other than a directory we

	 * can be sure create_new_entry() will NOT return an alternate

	 * dentry as d_splice_alias() only returns an alternate dentry

	 * for directories.  So we don't need to check for that case

	 * when passing back the result.

	 */

	WARN_ON_ONCE(S_ISDIR(mode));



	return PTR_ERR(create_new_entry(idmap, fm, args, dir, entry, mode));

}



static int fuse_mknod(struct mnt_idmap *idmap, struct inode *dir,
@@ -871,7 +885,7 @@ static int fuse_mknod(struct mnt_idmap *idmap, struct inode *dir, 
	args.in_args[0].value = &inarg;

	args.in_args[1].size = entry->d_name.len + 1;

	args.in_args[1].value = entry->d_name.name;

	return create_new_entry(idmap, fm, &args, dir, entry, mode);

	return create_new_nondir(idmap, fm, &args, dir, entry, mode);

}



static int fuse_create(struct mnt_idmap *idmap, struct inode *dir,
@@ -917,7 +931,7 @@ static struct dentry *fuse_mkdir(struct mnt_idmap *idmap, struct inode *dir, 
	args.in_args[0].value = &inarg;

	args.in_args[1].size = entry->d_name.len + 1;

	args.in_args[1].value = entry->d_name.name;

	return ERR_PTR(create_new_entry(idmap, fm, &args, dir, entry, S_IFDIR));

	return create_new_entry(idmap, fm, &args, dir, entry, S_IFDIR);

}



static int fuse_symlink(struct mnt_idmap *idmap, struct inode *dir,
@@ -934,7 +948,7 @@ static int fuse_symlink(struct mnt_idmap *idmap, struct inode *dir, 
	args.in_args[1].value = entry->d_name.name;

	args.in_args[2].size = len;

	args.in_args[2].value = link;

	return create_new_entry(idmap, fm, &args, dir, entry, S_IFLNK);

	return create_new_nondir(idmap, fm, &args, dir, entry, S_IFLNK);

}



void fuse_flush_time_update(struct inode *inode)
@@ -1131,7 +1145,7 @@ static int fuse_link(struct dentry *entry, struct inode *newdir, 
	args.in_args[0].value = &inarg;

	args.in_args[1].size = newent->d_name.len + 1;

	args.in_args[1].value = newent->d_name.name;

	err = create_new_entry(&invalid_mnt_idmap, fm, &args, newdir, newent, inode->i_mode);

	err = create_new_nondir(&invalid_mnt_idmap, fm, &args, newdir, newent, inode->i_mode);

	if (!err)

		fuse_update_ctime_in_cache(inode);

	else if (err == -EINTR)