buildroot/package/pkg-download.mk
Maxim Cournoyer 2e9d6565fc packages/pkg-download.mk: fix file locking over NFS
BSD style locks such as implemented by flock are translated to POSIX
advisory file locks (implemented by the fcntl system call on Linux).  It
is not possible to lock a directory using POSIX advisory file locks.
Hence, the lock strategy used by Buildroot doesn't work when used over
NFS.

Using flock on a simple file works correctly though, so use a '.lock'
file inside the download directory instead. If the lockfile does not
exist, flock will create it (in a race-free fashion).

Tested using NFS v4.2 and Linux 5.4.43.

Signed-off-by: Maxim Cournoyer <maxim.cournoyer@savoirfairelinux.com>
[yann.morin.1998@free.fr:
  - slightly expand commit log about creation of the lockfile
]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
2020-06-25 22:12:24 +02:00

117 lines
4.2 KiB
Makefile

################################################################################
#
# This file contains the download helpers for the various package
# infrastructures. It is used to handle downloads from HTTP servers,
# FTP servers, Git repositories, Subversion repositories, Mercurial
# repositories, Bazaar repositories, and SCP servers.
#
################################################################################
# Download method commands
export WGET := $(call qstrip,$(BR2_WGET))
export SVN := $(call qstrip,$(BR2_SVN))
export CVS := $(call qstrip,$(BR2_CVS))
export BZR := $(call qstrip,$(BR2_BZR))
export GIT := $(call qstrip,$(BR2_GIT))
export HG := $(call qstrip,$(BR2_HG))
export SCP := $(call qstrip,$(BR2_SCP))
export LOCALFILES := $(call qstrip,$(BR2_LOCALFILES))
DL_WRAPPER = support/download/dl-wrapper
# DL_DIR may have been set already from the environment
ifeq ($(origin DL_DIR),undefined)
DL_DIR ?= $(call qstrip,$(BR2_DL_DIR))
ifeq ($(DL_DIR),)
DL_DIR := $(TOPDIR)/dl
endif
else
# Restore the BR2_DL_DIR that was overridden by the .config file
BR2_DL_DIR = $(DL_DIR)
endif
# ensure it exists and a absolute path, derefrecing symlinks
DL_DIR := $(shell mkdir -p $(DL_DIR) && cd $(DL_DIR) >/dev/null && pwd -P)
#
# URI scheme helper functions
# Example URIs:
# * http://www.example.com/dir/file
# * scp://www.example.com:dir/file (with domainseparator :)
#
# geturischeme: http
geturischeme = $(firstword $(subst ://, ,$(call qstrip,$(1))))
# getschemeplusuri: git|parameter+http://example.com
getschemeplusuri = $(call geturischeme,$(1))$(if $(2),\|$(2))+$(1)
# stripurischeme: www.example.com/dir/file
stripurischeme = $(lastword $(subst ://, ,$(call qstrip,$(1))))
# domain: www.example.com
domain = $(firstword $(subst $(call domainseparator,$(2)), ,$(call stripurischeme,$(1))))
# notdomain: dir/file
notdomain = $(patsubst $(call domain,$(1),$(2))$(call domainseparator,$(2))%,%,$(call stripurischeme,$(1)))
#
# default domainseparator is /, specify alternative value as first argument
domainseparator = $(if $(1),$(1),/)
# github(user,package,version): returns site of GitHub repository
github = https://github.com/$(1)/$(2)/archive/$(3)
# Expressly do not check hashes for those files
# Exported variables default to immediately expanded in some versions of
# make, but we need it to be recursively-epxanded, so explicitly assign it.
export BR_NO_CHECK_HASH_FOR =
################################################################################
# DOWNLOAD_URIS - List the candidates URIs where to get the package from:
# 1) BR2_PRIMARY_SITE if enabled
# 2) Download site, unless BR2_PRIMARY_SITE_ONLY is set
# 3) BR2_BACKUP_SITE if enabled, unless BR2_PRIMARY_SITE_ONLY is set
#
# Argument 1 is the source location
# Argument 2 is the upper-case package name
#
################################################################################
ifneq ($(call qstrip,$(BR2_PRIMARY_SITE)),)
DOWNLOAD_URIS += \
$(call getschemeplusuri,$(call qstrip,$(BR2_PRIMARY_SITE)/$($(2)_DL_SUBDIR)),urlencode) \
$(call getschemeplusuri,$(call qstrip,$(BR2_PRIMARY_SITE)),urlencode)
endif
ifeq ($(BR2_PRIMARY_SITE_ONLY),)
DOWNLOAD_URIS += \
$(patsubst %/,%,$(dir $(call qstrip,$(1))))
ifneq ($(call qstrip,$(BR2_BACKUP_SITE)),)
DOWNLOAD_URIS += \
$(call getschemeplusuri,$(call qstrip,$(BR2_BACKUP_SITE)/$($(2)_DL_SUBDIR)),urlencode) \
$(call getschemeplusuri,$(call qstrip,$(BR2_BACKUP_SITE)),urlencode)
endif
endif
################################################################################
# DOWNLOAD -- Download helper. Will call DL_WRAPPER which will try to download
# source from the list returned by DOWNLOAD_URIS.
#
# Argument 1 is the source location
# Argument 2 is the upper-case package name
#
################################################################################
define DOWNLOAD
$(Q)mkdir -p $($(2)_DL_DIR)
$(Q)$(EXTRA_ENV) flock $($(2)_DL_DIR)/.lock $(DL_WRAPPER) \
-c '$($(2)_DL_VERSION)' \
-d '$($(2)_DL_DIR)' \
-D '$(DL_DIR)' \
-f '$(notdir $(1))' \
-H '$($(2)_HASH_FILE)' \
-n '$($(2)_BASENAME_RAW)' \
-N '$($(2)_RAWNAME)' \
-o '$($(2)_DL_DIR)/$(notdir $(1))' \
$(if $($(2)_GIT_SUBMODULES),-r) \
$(foreach uri,$(call DOWNLOAD_URIS,$(1),$(2)),-u $(uri)) \
$(QUIET) \
-- \
$($(2)_DL_OPTS)
endef