fs: Import EROFS from Huawei P10 HarmonyOS 2.0 kernel opensource

* Tarball file: VTR-AL00_02_HarmonyOS_opensource.tar.gz
* Corresponding software version: 2021-11-17

Change-Id: I4814be3f9f183dd431d93892532f6d29f14fc896

fs/Kconfig

@@ -251,6 +251,7 @@ source "fs/pstore/Kconfig"
 source "fs/sysv/Kconfig"
 source "fs/ufs/Kconfig"
 source "fs/exofs/Kconfig"
+source "fs/erofs/Kconfig"
 
 endif # MISC_FILESYSTEMS
 

fs/Makefile

@@ -136,3 +136,4 @@ obj-$(CONFIG_CEPH_FS)		+= ceph/
 obj-$(CONFIG_PSTORE)		+= pstore/
 obj-$(CONFIG_EFIVAR_FS)		+= efivarfs/
 obj-$(CONFIG_DYNAMIC_FSYNC)	+= dyn_sync_cntrl.o
+obj-$(CONFIG_EROFS_FS)		+= erofs/

fs/erofs/Kconfig

@@ -0,0 +1,158 @@
+# SPDX-License-Identifier: GPL-2.0
+
+config EROFS_FS
+	tristate "EROFS filesystem support"
+	depends on BLOCK
+	help
+	  EROFS(Enhanced Read-Only File System) is a lightweight
+	  read-only file system with modern designs (eg. page-sized
+	  blocks, inline xattrs/data, etc.) for scenarios which need
+	  high-performance read-only requirements, eg. firmwares in
+	  mobile phone or LIVECDs.
+
+	  It also provides VLE compression support, focusing on
+	  random read improvements, keeping relatively lower
+	  compression ratios, which is useful for high-performance
+	  devices with limited memory and ROM space.
+
+	  If unsure, say N.
+
+config EROFS_FS_DEBUG
+	bool "EROFS debugging feature"
+	depends on EROFS_FS
+	help
+	  Print EROFS debugging messages and enable more BUG_ONs
+	  which check the filesystem consistency aggressively.
+
+	  For daily use, say N.
+
+config EROFS_FS_XATTR
+	bool "EROFS extended attributes"
+	depends on EROFS_FS
+	default y
+	help
+	  Extended attributes are name:value pairs associated with inodes by
+	  the kernel or by users (see the attr(5) manual page, or visit
+	  <http://acl.bestbits.at/> for details).
+
+	  If unsure, say N.
+
+config EROFS_FS_POSIX_ACL
+	bool "EROFS Access Control Lists"
+	depends on EROFS_FS_XATTR
+	select FS_POSIX_ACL
+	default y
+	help
+	  Posix Access Control Lists (ACLs) support permissions for users and
+	  groups beyond the owner/group/world scheme.
+
+	  To learn more about Access Control Lists, visit the POSIX ACLs for
+	  Linux website <http://acl.bestbits.at/>.
+
+	  If you don't know what Access Control Lists are, say N.
+
+config EROFS_FS_SECURITY
+	bool "EROFS Security Labels"
+	depends on EROFS_FS_XATTR
+	help
+	  Security labels provide an access control facility to support Linux
+	  Security Models (LSMs) accepted by AppArmor, SELinux, Smack and TOMOYO
+	  Linux. This option enables an extended attribute handler for file
+	  security labels in the erofs filesystem, so that it requires enabling
+	  the extended attribute support in advance.
+
+	  If you are not using a security module, say N.
+
+config EROFS_FS_USE_VM_MAP_RAM
+	bool "EROFS VM_MAP_RAM Support"
+	depends on EROFS_FS
+	help
+	  use vm_map_ram/vm_unmap_ram instead of vmap/vunmap.
+
+	  If you don't know what these are, say N.
+
+config EROFS_FAULT_INJECTION
+	bool "EROFS fault injection facility"
+	depends on EROFS_FS
+	help
+	  Test EROFS to inject faults such as ENOMEM, EIO, and so on.
+	  If unsure, say N.
+
+config EROFS_FS_IO_MAX_RETRIES
+	int "EROFS IO Maximum Retries"
+	depends on EROFS_FS
+	default "5"
+	help
+	  Maximum retry count of IO Errors.
+
+	  If unsure, leave the default value (5 retries, 6 IOs at most).
+
+config EROFS_FS_ZIP
+	bool "EROFS Data Compresssion Support"
+	depends on EROFS_FS
+	help
+	  Currently we support VLE Compression only.
+	  Play at your own risk.
+
+	  If you don't want to use compression feature, say N.
+
+config EROFS_FS_CLUSTER_PAGE_LIMIT
+	int "EROFS Cluster Pages Hard Limit"
+	depends on EROFS_FS_ZIP
+	range 1 256
+	default "1"
+	help
+	  Indicates VLE compressed pages hard limit of a
+	  compressed cluster.
+
+	  For example, if files of a image are compressed
+	  into 8k-unit, the hard limit should not be less
+	  than 2. Otherwise, the image cannot be mounted
+	  correctly on this kernel.
+
+choice
+	prompt "EROFS VLE Data Decompression mode"
+	depends on EROFS_FS_ZIP
+	default EROFS_FS_ZIP_CACHE_BIPOLAR
+	help
+	  EROFS supports three options for VLE decompression.
+	  "In-place Decompression Only" consumes the minimum memory
+	  with lowest random read.
+
+	  "Bipolar Cached Decompression" consumes the maximum memory
+	  with highest random read.
+
+	  If unsure, select "Bipolar Cached Decompression"
+
+config EROFS_FS_ZIP_NO_CACHE
+	bool "In-place Decompression Only"
+	help
+	  Read compressed data into page cache and do in-place
+	  decompression directly.
+
+config EROFS_FS_ZIP_CACHE_UNIPOLAR
+	bool "Unipolar Cached Decompression"
+	help
+	  For each request, it caches the last compressed page
+	  for further reading.
+	  It still decompresses in place for the rest compressed pages.
+
+config EROFS_FS_ZIP_CACHE_BIPOLAR
+	bool "Bipolar Cached Decompression"
+	help
+	  For each request, it caches the both end compressed pages
+	  for further reading.
+	  It still decompresses in place for the rest compressed pages.
+
+	  Recommended for performance priority.
+
+endchoice
+
+config EROFS_FS_HUAWEI_EXTENSION
+	bool "EROFS HUAWEI Extension"
+	depends on EROFS_FS && EROFS_FS_ZIP
+	help
+	  Targeted optimizations for HUAWEI Mobile phone.
+
+	  If unsure, say N.
+

fs/erofs/Makefile

@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: GPL-2.0
+
+EROFS_VERSION = "0.5.180822.0"
+
+ccflags-y += -Wall -DEROFS_VERSION=\"$(EROFS_VERSION)\"
+
+obj-$(CONFIG_EROFS_FS) += erofs.o
+# staging requirement: to be self-contained in its own directory
+ccflags-y += -I$(src)/include
+erofs-objs := super.o inode.o data.o namei.o dir.o utils.o
+erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o
+erofs-$(CONFIG_EROFS_FS_ZIP) += unzip_vle.o unzip_vle_lz4.o
+
+# lz4 algorithm related stuffs
+erofs-$(CONFIG_EROFS_FS_ZIP) += unzip_lz4.o
+erofs-$(CONFIG_ARM64) += $(addprefix lz4armv8/, \
+			   lz4armv8.o		\
+			   lz4accel.o		\
+			   )
+CFLAGS_unzip_lz4.o += -O3
+