cifs: Extract DFS referral expansion logic to separate function (dd613945) · Commits · 戴 / test

fs/cifs/connect.c

+69 −36

Original line number	Diff line number	Diff line
		@@ -2745,6 +2745,57 @@ build_unc_path_to_root(const struct smb_vol *volume_info,
		full_path[unc_len + cifs_sb->prepathlen] = 0; /* add trailing null */
		return full_path;
		}

		/*
		* Perform a dfs referral query for a share and (optionally) prefix
		*
		* If a referral is found, mount_data will be set to point at a newly
		* allocated string containing updated options for the submount.
		* Otherwise it will be left untouched.
		*
		* Returns the rc from get_dfs_path to the caller, which can be used to
		* determine whether there were referrals.
		*/
		static int
		expand_dfs_referral(int xid, struct cifsSesInfo *pSesInfo,
		struct smb_vol volume_info, struct cifs_sb_info cifs_sb,
		char **mount_data, int check_prefix)
		{
		int rc;
		unsigned int num_referrals = 0;
		struct dfs_info3_param *referrals = NULL;
		char full_path = NULL, ref_path = NULL, *mdata = NULL;

		full_path = build_unc_path_to_root(volume_info, cifs_sb);
		if (IS_ERR(full_path))
		return PTR_ERR(full_path);

		/* For DFS paths, skip the first '\' of the UNC */
		ref_path = check_prefix ? full_path + 1 : volume_info->UNC + 1;

		rc = get_dfs_path(xid, pSesInfo , ref_path, cifs_sb->local_nls,
		&num_referrals, &referrals,
		cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);

		if (!rc && num_referrals > 0) {
		char *fake_devname = NULL;

		mdata = cifs_compose_mount_options(cifs_sb->mountdata,
		full_path + 1, referrals,
		&fake_devname);

		free_dfs_info_array(referrals, num_referrals);
		kfree(fake_devname);

		if (IS_ERR(mdata)) {
		rc = PTR_ERR(mdata);
		mdata = NULL;
		}
		*mount_data = mdata;
		}
		kfree(full_path);
		return rc;
		}
		#endif

		int
		@@ -2761,10 +2812,19 @@ cifs_mount(struct super_block sb, struct cifs_sb_info cifs_sb,
		char *mount_data = mount_data_global;
		struct tcon_link *tlink;
		#ifdef CONFIG_CIFS_DFS_UPCALL
		struct dfs_info3_param *referrals = NULL;
		unsigned int num_referrals = 0;
		int referral_walks_count = 0;
		try_mount_again:

		/* cleanup activities if we're chasing a referral */
		if (referral_walks_count) {
		if (tcon)
		cifs_put_tcon(tcon);
		else if (pSesInfo)
		cifs_put_smb_ses(pSesInfo);

		cleanup_volume_info(&volume_info);
		FreeXid(xid);
		}
		#endif
		rc = 0;
		tcon = NULL;
		@@ -2910,46 +2970,19 @@ remote_path_check:
		if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) == 0)
		convert_delimiter(cifs_sb->prepath,
		CIFS_DIR_SEP(cifs_sb));
		full_path = build_unc_path_to_root(volume_info, cifs_sb);
		if (IS_ERR(full_path)) {
		rc = PTR_ERR(full_path);
		goto mount_fail_check;
		}

		cFYI(1, "Getting referral for: %s", full_path);
		rc = get_dfs_path(xid, pSesInfo , full_path + 1,
		cifs_sb->local_nls, &num_referrals, &referrals,
		cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
		if (!rc && num_referrals > 0) {
		char *fake_devname = NULL;

		if (mount_data != mount_data_global)
		kfree(mount_data);

		mount_data = cifs_compose_mount_options(
		cifs_sb->mountdata, full_path + 1,
		referrals, &fake_devname);

		free_dfs_info_array(referrals, num_referrals);
		kfree(fake_devname);
		kfree(full_path);

		if (IS_ERR(mount_data)) {
		rc = PTR_ERR(mount_data);
		mount_data = NULL;
		goto mount_fail_check;
		}

		if (tcon)
		cifs_put_tcon(tcon);
		else if (pSesInfo)
		cifs_put_smb_ses(pSesInfo);
		rc = expand_dfs_referral(xid, pSesInfo, volume_info, cifs_sb,
		&mount_data, true);

		cleanup_volume_info(&volume_info);
		if (!rc) {
		referral_walks_count++;
		FreeXid(xid);
		goto try_mount_again;
		}
		mount_data = NULL;
		goto mount_fail_check;
		#else /* No DFS support, return error on mount */
		rc = -EOPNOTSUPP;
		#endif

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