Commit ec7bbb53 authored by Amir Goldstein's avatar Amir Goldstein Committed by Miklos Szeredi
Browse files

ovl: don't use a temp buf for encoding real fh 



We can allocate maximum fh size and encode into it directly.

Suggested-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent cbe7fba8

fs/overlayfs/copy_up.c

+16 −21
Original line number Diff line number Diff line
@@ -227,13 +227,17 @@ int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat) 
struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper)

{

	struct ovl_fh *fh;

	int fh_type, fh_len, dwords;

	void *buf;

	int fh_type, dwords;

	int buflen = MAX_HANDLE_SZ;

	uuid_t *uuid = &real->d_sb->s_uuid;

	int err;



	buf = kmalloc(buflen, GFP_KERNEL);

	if (!buf)

	/* Make sure the real fid stays 32bit aligned */

	BUILD_BUG_ON(OVL_FH_FID_OFFSET % 4);

	BUILD_BUG_ON(MAX_HANDLE_SZ + OVL_FH_FID_OFFSET > 255);



	fh = kzalloc(buflen + OVL_FH_FID_OFFSET, GFP_KERNEL);

	if (!fh)

		return ERR_PTR(-ENOMEM);



	/*
@@ -242,24 +246,14 @@ struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper) 
	 * the price or reconnecting the dentry.

	 */

	dwords = buflen >> 2;

	fh_type = exportfs_encode_fh(real, buf, &dwords, 0);

	fh_type = exportfs_encode_fh(real, (void *)fh->fb.fid, &dwords, 0);

	buflen = (dwords << 2);



	fh = ERR_PTR(-EIO);

	err = -EIO;

	if (WARN_ON(fh_type < 0) ||

	    WARN_ON(buflen > MAX_HANDLE_SZ) ||

	    WARN_ON(fh_type == FILEID_INVALID))

		goto out;



	/* Make sure the real fid stays 32bit aligned */

	BUILD_BUG_ON(OVL_FH_FID_OFFSET % 4);

	BUILD_BUG_ON(MAX_HANDLE_SZ + OVL_FH_FID_OFFSET > 255);

	fh_len = OVL_FH_FID_OFFSET + buflen;

	fh = kzalloc(fh_len, GFP_KERNEL);

	if (!fh) {

		fh = ERR_PTR(-ENOMEM);

		goto out;

	}

		goto out_err;



	fh->fb.version = OVL_FH_VERSION;

	fh->fb.magic = OVL_FH_MAGIC;
@@ -273,13 +267,14 @@ struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper) 
	 */

	if (is_upper)

		fh->fb.flags |= OVL_FH_FLAG_PATH_UPPER;

	fh->fb.len = fh_len - OVL_FH_WIRE_OFFSET;

	fh->fb.len = sizeof(fh->fb) + buflen;

	fh->fb.uuid = *uuid;

	memcpy(fh->fb.fid, buf, buflen);



out:

	kfree(buf);

	return fh;



out_err:

	kfree(fh);

	return ERR_PTR(err);

}



int ovl_set_origin(struct dentry *dentry, struct dentry *lower,