ovl: don't use a temp buf for encoding real fh (ec7bbb53) · Commits · 戴 / test

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,

Admin message