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[PATCH v13 2/3] fs/erofs: Add support for EROFS
|
From: |
Gao Xiang |
|
Subject: |
[PATCH v13 2/3] fs/erofs: Add support for EROFS |
|
Date: |
Fri, 17 May 2024 20:17:27 +0800 |
From: Yifan Zhao <zhaoyifan@sjtu.edu.cn>
EROFS [1] is a lightweight read-only filesystem designed for performance
which has already been shipped in most Linux distributions as well as widely
used in several scenarios, such as Android system partitions, container
images, and rootfs for embedded devices.
This patch brings EROFS uncompressed support. Now, it's possible to boot
directly through GRUB with an EROFS rootfs.
EROFS compressed files will be supported later since it has more work to
polish.
[1] https://erofs.docs.kernel.org
Signed-off-by: Yifan Zhao <zhaoyifan@sjtu.edu.cn>
Tested-by: Daniel Axtens <dja@axtens.net> # fuzz testing only
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
---
INSTALL | 8 +-
Makefile.util.def | 1 +
docs/grub.texi | 3 +-
grub-core/Makefile.core.def | 5 +
grub-core/fs/erofs.c | 1000 +++++++++++++++++++++++++++++++++++
5 files changed, 1012 insertions(+), 5 deletions(-)
create mode 100644 grub-core/fs/erofs.c
diff --git a/INSTALL b/INSTALL
index 8d9207c84..84030c9f4 100644
--- a/INSTALL
+++ b/INSTALL
@@ -77,15 +77,15 @@ Prerequisites for make-check:
* If running a Linux kernel the following modules must be loaded:
- fuse, loop
- - btrfs, ext4, f2fs, fat, hfs, hfsplus, jfs, mac-roman, minix, nilfs2,
+ - btrfs, erofs, ext4, f2fs, fat, hfs, hfsplus, jfs, mac-roman, minix, nilfs2,
reiserfs, udf, xfs
- On newer kernels, the exfat kernel modules may be used instead of the
exfat FUSE filesystem
* The following are Debian named packages required mostly for the full
suite of filesystem testing (but some are needed by other tests as well):
- - btrfs-progs, dosfstools, e2fsprogs, exfat-utils, f2fs-tools, genromfs,
- hfsprogs, jfsutils, nilfs-tools, ntfs-3g, reiserfsprogs, squashfs-tools,
- reiserfsprogs, udftools, xfsprogs, zfs-fuse
+ - btrfs-progs, dosfstools, e2fsprogs, erofs-utils, exfat-utils, f2fs-tools,
+ genromfs, hfsprogs, jfsutils, nilfs-tools, ntfs-3g, reiserfsprogs,
+ squashfs-tools, reiserfsprogs, udftools, xfsprogs, zfs-fuse
- exfat-fuse, if not using the exfat kernel module
- gzip, lzop, xz-utils
- attr, cpio, g++, gawk, parted, recode, tar, util-linux
diff --git a/Makefile.util.def b/Makefile.util.def
index 9432365a9..8d3bc107f 100644
--- a/Makefile.util.def
+++ b/Makefile.util.def
@@ -98,6 +98,7 @@ library = {
common = grub-core/fs/cpio_be.c;
common = grub-core/fs/odc.c;
common = grub-core/fs/newc.c;
+ common = grub-core/fs/erofs.c;
common = grub-core/fs/ext2.c;
common = grub-core/fs/fat.c;
common = grub-core/fs/exfat.c;
diff --git a/docs/grub.texi b/docs/grub.texi
index d32266f69..b198d963d 100644
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -353,6 +353,7 @@ blocklist notation. The currently supported filesystem
types are @dfn{Amiga
Fast FileSystem (AFFS)}, @dfn{AtheOS fs}, @dfn{BeFS},
@dfn{BtrFS} (including raid0, raid1, raid10, gzip and lzo),
@dfn{cpio} (little- and big-endian bin, odc and newc variants),
+@dfn{EROFS} (only uncompressed support for now),
@dfn{Linux ext2/ext3/ext4}, @dfn{DOS FAT12/FAT16/FAT32},
@dfn{exFAT}, @dfn{F2FS}, @dfn{HFS}, @dfn{HFS+},
@dfn{ISO9660} (including Joliet, Rock-ridge and multi-chunk files),
@@ -6276,7 +6277,7 @@ assumed to be encoded in UTF-8.
NTFS, JFS, UDF, HFS+, exFAT, long filenames in FAT, Joliet part of
ISO9660 are treated as UTF-16 as per specification. AFS and BFS are read
as UTF-8, again according to specification. BtrFS, cpio, tar, squash4, minix,
-minix2, minix3, ROMFS, ReiserFS, XFS, ext2, ext3, ext4, FAT (short names),
+minix2, minix3, ROMFS, ReiserFS, XFS, EROFS, ext2, ext3, ext4, FAT (short
names),
F2FS, RockRidge part of ISO9660, nilfs2, UFS1, UFS2 and ZFS are assumed
to be UTF-8. This might be false on systems configured with legacy charset
but as long as the charset used is superset of ASCII you should be able to
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 8e1b1d9f3..7fa9446bd 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -1442,6 +1442,11 @@ module = {
common = fs/odc.c;
};
+module = {
+ name = erofs;
+ common = fs/erofs.c;
+};
+
module = {
name = ext2;
common = fs/ext2.c;
diff --git a/grub-core/fs/erofs.c b/grub-core/fs/erofs.c
new file mode 100644
index 000000000..005d975de
--- /dev/null
+++ b/grub-core/fs/erofs.c
@@ -0,0 +1,1000 @@
+/* erofs.c - Enhanced Read-Only File System */
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2024 Free Software Foundation, Inc.
+ *
+ * GRUB is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GRUB. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/disk.h>
+#include <grub/dl.h>
+#include <grub/err.h>
+#include <grub/file.h>
+#include <grub/fs.h>
+#include <grub/fshelp.h>
+#include <grub/misc.h>
+#include <grub/mm.h>
+#include <grub/safemath.h>
+#include <grub/types.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+#define EROFS_SUPER_OFFSET 1024
+#define EROFS_MAGIC 0xE0F5E1E2
+#define EROFS_ISLOTBITS 5
+
+#define EROFS_FEATURE_INCOMPAT_CHUNKED_FILE 0x00000004
+#define EROFS_ALL_FEATURE_INCOMPAT
EROFS_FEATURE_INCOMPAT_CHUNKED_FILE
+
+struct grub_erofs_super
+{
+ grub_uint32_t magic;
+ grub_uint32_t checksum;
+ grub_uint32_t feature_compat;
+ grub_uint8_t log2_blksz;
+ grub_uint8_t sb_extslots;
+
+ grub_uint16_t root_nid;
+ grub_uint64_t inos;
+
+ grub_uint64_t build_time;
+ grub_uint32_t build_time_nsec;
+ grub_uint32_t blocks;
+ grub_uint32_t meta_blkaddr;
+ grub_uint32_t xattr_blkaddr;
+ grub_packed_guid_t uuid;
+ grub_uint8_t volume_name[16];
+ grub_uint32_t feature_incompat;
+
+ union
+ {
+ grub_uint16_t available_compr_algs;
+ grub_uint16_t lz4_max_distance;
+ } GRUB_PACKED u1;
+
+ grub_uint16_t extra_devices;
+ grub_uint16_t devt_slotoff;
+ grub_uint8_t log2_dirblksz;
+ grub_uint8_t xattr_prefix_count;
+ grub_uint32_t xattr_prefix_start;
+ grub_uint64_t packed_nid;
+ grub_uint8_t reserved2[24];
+} GRUB_PACKED;
+
+#define EROFS_INODE_LAYOUT_COMPACT 0
+#define EROFS_INODE_LAYOUT_EXTENDED 1
+
+#define EROFS_INODE_FLAT_PLAIN 0
+#define EROFS_INODE_COMPRESSED_FULL 1
+#define EROFS_INODE_FLAT_INLINE 2
+#define EROFS_INODE_COMPRESSED_COMPACT 3
+#define EROFS_INODE_CHUNK_BASED 4
+
+#define EROFS_I_VERSION_MASKS 0x01
+#define EROFS_I_DATALAYOUT_MASKS 0x07
+
+#define EROFS_I_VERSION_BIT 0
+#define EROFS_I_DATALAYOUT_BIT 1
+
+struct grub_erofs_inode_chunk_info
+{
+ grub_uint16_t format;
+ grub_uint16_t reserved;
+} GRUB_PACKED;
+
+#define EROFS_CHUNK_FORMAT_BLKBITS_MASK 0x001F
+#define EROFS_CHUNK_FORMAT_INDEXES 0x0020
+
+#define EROFS_BLOCK_MAP_ENTRY_SIZE 4
+#define EROFS_MAP_MAPPED 0x02
+
+#define EROFS_NULL_ADDR 1
+#define EROFS_NAME_LEN 255
+#define EROFS_PATH_LEN 4096
+#define EROFS_MIN_LOG2_BLOCK_SIZE 9
+#define EROFS_MAX_LOG2_BLOCK_SIZE 16
+
+struct grub_erofs_inode_chunk_index
+{
+ grub_uint16_t advise;
+ grub_uint16_t device_id;
+ grub_uint32_t blkaddr;
+};
+
+union grub_erofs_inode_i_u
+{
+ grub_uint32_t compressed_blocks;
+ grub_uint32_t raw_blkaddr;
+
+ grub_uint32_t rdev;
+
+ struct grub_erofs_inode_chunk_info c;
+};
+
+struct grub_erofs_inode_compact
+{
+ grub_uint16_t i_format;
+
+ grub_uint16_t i_xattr_icount;
+ grub_uint16_t i_mode;
+ grub_uint16_t i_nlink;
+ grub_uint32_t i_size;
+ grub_uint32_t i_reserved;
+
+ union grub_erofs_inode_i_u i_u;
+
+ grub_uint32_t i_ino;
+ grub_uint16_t i_uid;
+ grub_uint16_t i_gid;
+ grub_uint32_t i_reserved2;
+} GRUB_PACKED;
+
+struct grub_erofs_inode_extended
+{
+ grub_uint16_t i_format;
+
+ grub_uint16_t i_xattr_icount;
+ grub_uint16_t i_mode;
+ grub_uint16_t i_reserved;
+ grub_uint64_t i_size;
+
+ union grub_erofs_inode_i_u i_u;
+
+ grub_uint32_t i_ino;
+
+ grub_uint32_t i_uid;
+ grub_uint32_t i_gid;
+ grub_uint64_t i_mtime;
+ grub_uint32_t i_mtime_nsec;
+ grub_uint32_t i_nlink;
+ grub_uint8_t i_reserved2[16];
+} GRUB_PACKED;
+
+union grub_erofs_inode
+{
+ struct grub_erofs_inode_compact c;
+ struct grub_erofs_inode_extended e;
+} GRUB_PACKED;
+
+#define EROFS_FT_UNKNOWN 0
+#define EROFS_FT_REG_FILE 1
+#define EROFS_FT_DIR 2
+#define EROFS_FT_CHRDEV 3
+#define EROFS_FT_BLKDEV 4
+#define EROFS_FT_FIFO 5
+#define EROFS_FT_SOCK 6
+#define EROFS_FT_SYMLINK 7
+
+struct grub_erofs_dirent
+{
+ grub_uint64_t nid;
+ grub_uint16_t nameoff;
+ grub_uint8_t file_type;
+ grub_uint8_t reserved;
+} GRUB_PACKED;
+
+struct grub_erofs_map_blocks
+{
+ grub_uint64_t m_pa; /* physical address */
+ grub_uint64_t m_la; /* logical address */
+ grub_uint64_t m_plen; /* physical length */
+ grub_uint64_t m_llen; /* logical length */
+ grub_uint32_t m_flags;
+};
+
+struct grub_erofs_xattr_ibody_header
+{
+ grub_uint32_t h_reserved;
+ grub_uint8_t h_shared_count;
+ grub_uint8_t h_reserved2[7];
+ grub_uint32_t h_shared_xattrs[0];
+};
+
+struct grub_fshelp_node
+{
+ struct grub_erofs_data *data;
+ union grub_erofs_inode inode;
+
+ grub_uint64_t ino;
+ grub_uint8_t inode_type;
+ grub_uint8_t inode_datalayout;
+
+ /* If the inode has been read into memory? */
+ bool inode_loaded;
+};
+
+struct grub_erofs_data
+{
+ grub_disk_t disk;
+ struct grub_erofs_super sb;
+
+ struct grub_fshelp_node inode;
+};
+
+#define erofs_blocksz(data) (((grub_uint32_t) 1) << data->sb.log2_blksz)
+
+static grub_size_t
+grub_erofs_strnlen (const char *s, grub_size_t n)
+{
+ const char *p = s;
+
+ if (n == 0)
+ return 0;
+
+ while (n-- && *p)
+ p++;
+
+ return p - s;
+}
+
+static grub_uint64_t
+erofs_iloc (grub_fshelp_node_t node)
+{
+ struct grub_erofs_super *sb = &node->data->sb;
+
+ return ((grub_uint64_t) grub_le_to_cpu32 (sb->meta_blkaddr) <<
sb->log2_blksz) +
+ (node->ino << EROFS_ISLOTBITS);
+}
+
+static grub_err_t
+erofs_read_inode (struct grub_erofs_data *data, grub_fshelp_node_t node)
+{
+ union grub_erofs_inode *di;
+ grub_err_t err;
+ grub_uint16_t i_format;
+ grub_uint64_t addr = erofs_iloc (node);
+
+ di = (union grub_erofs_inode *) &node->inode;
+
+ err = grub_disk_read (data->disk, addr >> GRUB_DISK_SECTOR_BITS,
+ addr & (GRUB_DISK_SECTOR_SIZE - 1),
+ sizeof (struct grub_erofs_inode_compact), &di->c);
+ if (err != GRUB_ERR_NONE)
+ return err;
+
+ i_format = grub_le_to_cpu16 (di->c.i_format);
+ node->inode_type = (i_format >> EROFS_I_VERSION_BIT) & EROFS_I_VERSION_MASKS;
+ node->inode_datalayout = (i_format >> EROFS_I_DATALAYOUT_BIT) &
EROFS_I_DATALAYOUT_MASKS;
+
+ switch (node->inode_type)
+ {
+ case EROFS_INODE_LAYOUT_EXTENDED:
+ addr += sizeof (struct grub_erofs_inode_compact);
+ err = grub_disk_read (data->disk, addr >> GRUB_DISK_SECTOR_BITS,
+ addr & (GRUB_DISK_SECTOR_SIZE - 1),
+ sizeof (struct grub_erofs_inode_extended) - sizeof
(struct grub_erofs_inode_compact),
+ (grub_uint8_t *) di + sizeof (struct
grub_erofs_inode_compact));
+ if (err != GRUB_ERR_NONE)
+ return err;
+ break;
+ case EROFS_INODE_LAYOUT_COMPACT:
+ break;
+ default:
+ return grub_error (GRUB_ERR_BAD_FS, "invalid type %u @ inode %"
PRIuGRUB_UINT64_T,
+ node->inode_type, node->ino);
+ }
+
+ node->inode_loaded = true;
+
+ return 0;
+}
+
+static grub_uint64_t
+erofs_inode_size (grub_fshelp_node_t node)
+{
+ return node->inode_type == EROFS_INODE_LAYOUT_COMPACT
+ ? sizeof (struct grub_erofs_inode_compact)
+ : sizeof (struct grub_erofs_inode_extended);
+}
+
+static grub_uint64_t
+erofs_inode_file_size (grub_fshelp_node_t node)
+{
+ union grub_erofs_inode *di = (union grub_erofs_inode *) &node->inode;
+
+ return node->inode_type == EROFS_INODE_LAYOUT_COMPACT
+ ? grub_le_to_cpu32 (di->c.i_size)
+ : grub_le_to_cpu64 (di->e.i_size);
+}
+
+static grub_uint32_t
+erofs_inode_xattr_ibody_size (grub_fshelp_node_t node)
+{
+ grub_uint16_t cnt = grub_le_to_cpu16 (node->inode.e.i_xattr_icount);
+
+ if (cnt == 0)
+ return 0;
+
+ return sizeof (struct grub_erofs_xattr_ibody_header) + ((cnt - 1) * sizeof
(grub_uint32_t));
+}
+
+static grub_uint64_t
+erofs_inode_mtime (grub_fshelp_node_t node)
+{
+ return node->inode_type == EROFS_INODE_LAYOUT_COMPACT
+ ? grub_le_to_cpu64 (node->data->sb.build_time)
+ : grub_le_to_cpu64 (node->inode.e.i_mtime);
+}
+
+static grub_err_t
+erofs_map_blocks_flatmode (grub_fshelp_node_t node,
+ struct grub_erofs_map_blocks *map)
+{
+ grub_uint64_t nblocks, lastblk, file_size;
+ bool tailendpacking = (node->inode_datalayout == EROFS_INODE_FLAT_INLINE);
+ grub_uint64_t blocksz = erofs_blocksz (node->data);
+
+ /* `file_size` is checked by caller and cannot be zero, hence nblocks > 0. */
+ file_size = erofs_inode_file_size (node);
+ if (grub_add (file_size, blocksz - 1, &nblocks))
+ return grub_error (GRUB_ERR_OUT_OF_RANGE, "nblocks overflow");
+ nblocks >>= node->data->sb.log2_blksz;
+ lastblk = nblocks - tailendpacking;
+
+ map->m_flags = EROFS_MAP_MAPPED;
+
+ /* No overflow as (lastblk <= nblocks) && (nblocks * blocksz <= UINT64_MAX -
blocksz + 1). */
+ if (map->m_la < (lastblk * blocksz))
+ {
+ if (grub_mul ((grub_uint64_t) grub_le_to_cpu32
(node->inode.e.i_u.raw_blkaddr), blocksz, &map->m_pa) ||
+ grub_add (map->m_pa, map->m_la, &map->m_pa))
+ return grub_error (GRUB_ERR_OUT_OF_RANGE, "m_pa overflow");
+ if (grub_sub (lastblk * blocksz, map->m_la, &map->m_plen))
+ return grub_error (GRUB_ERR_OUT_OF_RANGE, "m_plen underflow");
+ }
+ else if (tailendpacking)
+ {
+ if (grub_add (erofs_iloc (node), erofs_inode_size (node), &map->m_pa) ||
+ grub_add (map->m_pa, erofs_inode_xattr_ibody_size (node), &map->m_pa)
||
+ grub_add (map->m_pa, map->m_la % blocksz, &map->m_pa))
+ return grub_error (GRUB_ERR_OUT_OF_RANGE, "m_pa overflow when handling
tailpacking");
+ if (grub_sub (file_size, map->m_la, &map->m_plen))
+ return grub_error (GRUB_ERR_OUT_OF_RANGE, "m_plen overflow when
handling tailpacking");
+
+ /* No overflow as map->m_plen <= UINT64_MAX - blocksz + 1. */
+ if (((map->m_pa % blocksz) + map->m_plen) > blocksz)
+ return grub_error (GRUB_ERR_BAD_FS,
+ "inline data cross block boundary @ inode %"
PRIuGRUB_UINT64_T,
+ node->ino);
+ }
+ else
+ return grub_error (GRUB_ERR_BAD_FS,
+ "invalid map->m_la=%" PRIuGRUB_UINT64_T
+ " @ inode %" PRIuGRUB_UINT64_T,
+ map->m_la, node->ino);
+
+ map->m_llen = map->m_plen;
+ return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+erofs_map_blocks_chunkmode (grub_fshelp_node_t node,
+ struct grub_erofs_map_blocks *map)
+{
+ grub_uint16_t chunk_format = grub_le_to_cpu16 (node->inode.e.i_u.c.format);
+ grub_uint64_t unit, pos, chunknr, blkaddr;
+ grub_uint8_t chunkbits;
+ grub_err_t err;
+
+ if (chunk_format & EROFS_CHUNK_FORMAT_INDEXES)
+ unit = sizeof (struct grub_erofs_inode_chunk_index);
+ else
+ unit = EROFS_BLOCK_MAP_ENTRY_SIZE;
+
+ chunkbits = node->data->sb.log2_blksz + (chunk_format &
EROFS_CHUNK_FORMAT_BLKBITS_MASK);
+ if (chunkbits > 63)
+ return grub_error (GRUB_ERR_BAD_FS, "invalid chunkbits %u @ inode %"
PRIuGRUB_UINT64_T,
+ chunkbits, node->ino);
+
+ chunknr = map->m_la >> chunkbits;
+
+ if (grub_add (erofs_iloc (node), erofs_inode_size (node), &pos))
+ return grub_error (GRUB_ERR_OUT_OF_RANGE, "chunkmap position overflow when
adding inode size");
+
+ if (grub_add (pos, erofs_inode_xattr_ibody_size (node), &pos))
+ return grub_error (GRUB_ERR_OUT_OF_RANGE, "chunkmap position overflow when
adding xattr size");
+
+ if (ALIGN_UP_OVF (pos, unit - 1, &pos))
+ return grub_error (GRUB_ERR_OUT_OF_RANGE, "position overflow when seeking
at the start of chunkmap");
+
+ /* No overflow for multiplication as chunkbits >= 9 and sizeof(unit) <= 8. */
+ if (grub_add (pos, chunknr * unit, &pos))
+ return grub_error (GRUB_ERR_OUT_OF_RANGE, "chunkmap position overflow when
finding the specific chunk");
+
+ map->m_la = chunknr << chunkbits;
+
+ if (grub_sub (erofs_inode_file_size (node), map->m_la, &map->m_plen))
+ return grub_error (GRUB_ERR_OUT_OF_RANGE, "m_plen underflow");
+ map->m_plen = grub_min (((grub_uint64_t) 1) << chunkbits,
+ ALIGN_UP (map->m_plen, erofs_blocksz (node->data)));
+
+ if (chunk_format & EROFS_CHUNK_FORMAT_INDEXES)
+ {
+ struct grub_erofs_inode_chunk_index idx;
+
+ err = grub_disk_read (node->data->disk, pos >> GRUB_DISK_SECTOR_BITS,
+ pos & (GRUB_DISK_SECTOR_SIZE - 1), unit, &idx);
+ if (err != GRUB_ERR_NONE)
+ return err;
+
+ blkaddr = grub_le_to_cpu32 (idx.blkaddr);
+ }
+ else
+ {
+ grub_uint32_t blkaddr_le;
+
+ err = grub_disk_read (node->data->disk, pos >> GRUB_DISK_SECTOR_BITS,
+ pos & (GRUB_DISK_SECTOR_SIZE - 1), unit,
&blkaddr_le);
+ if (err != GRUB_ERR_NONE)
+ return err;
+
+ blkaddr = grub_le_to_cpu32 (blkaddr_le);
+ }
+
+ if (blkaddr == EROFS_NULL_ADDR)
+ {
+ map->m_pa = 0;
+ map->m_flags = 0;
+ }
+ else
+ {
+ map->m_pa = blkaddr << node->data->sb.log2_blksz;
+ map->m_flags = EROFS_MAP_MAPPED;
+ }
+
+ map->m_llen = map->m_plen;
+ return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+erofs_map_blocks (grub_fshelp_node_t node, struct grub_erofs_map_blocks *map)
+{
+ if (map->m_la >= erofs_inode_file_size (node))
+ {
+ map->m_llen = map->m_plen = 0;
+ map->m_pa = 0;
+ map->m_flags = 0;
+ return GRUB_ERR_NONE;
+ }
+
+ if (node->inode_datalayout != EROFS_INODE_CHUNK_BASED)
+ return erofs_map_blocks_flatmode (node, map);
+ else
+ return erofs_map_blocks_chunkmode (node, map);
+}
+
+static grub_err_t
+erofs_read_raw_data (grub_fshelp_node_t node, grub_uint8_t *buf, grub_uint64_t
size,
+ grub_uint64_t offset, grub_uint64_t *bytes)
+{
+ struct grub_erofs_map_blocks map = {0};
+ grub_uint64_t cur;
+ grub_err_t err;
+
+ if (bytes)
+ *bytes = 0;
+
+ if (node->inode_loaded == false)
+ {
+ err = erofs_read_inode (node->data, node);
+ if (err != GRUB_ERR_NONE)
+ return err;
+ }
+
+ cur = offset;
+ while (cur < offset + size)
+ {
+ grub_uint8_t *const estart = buf + cur - offset;
+ grub_uint64_t eend, moff = 0;
+
+ map.m_la = cur;
+ err = erofs_map_blocks (node, &map);
+ if (err != GRUB_ERR_NONE)
+ return err;
+
+ if (grub_add(map.m_la, map.m_llen, &eend))
+ return grub_error (GRUB_ERR_OUT_OF_RANGE, "eend overflow");
+
+ eend = grub_min (eend, offset + size);
+ if (!(map.m_flags & EROFS_MAP_MAPPED))
+ {
+ if (!map.m_llen)
+ {
+ /* Reached EOF. */
+ grub_memset (estart, 0, offset + size - cur);
+ cur = offset + size;
+ continue;
+ }
+
+ /* It's a hole. */
+ grub_memset (estart, 0, eend - cur);
+ if (bytes)
+ *bytes += eend - cur;
+ cur = eend;
+ continue;
+ }
+
+ if (cur > map.m_la)
+ {
+ moff = cur - map.m_la;
+ map.m_la = cur;
+ }
+
+ err = grub_disk_read (node->data->disk,
+ (map.m_pa + moff) >> GRUB_DISK_SECTOR_BITS,
+ (map.m_pa + moff) & (GRUB_DISK_SECTOR_SIZE - 1),
+ eend - map.m_la, estart);
+ if (err != GRUB_ERR_NONE)
+ return err;
+
+ if (bytes)
+ *bytes += eend - map.m_la;
+
+ cur = eend;
+ }
+
+ return GRUB_ERR_NONE;
+}
+
+static int
+erofs_iterate_dir (grub_fshelp_node_t dir, grub_fshelp_iterate_dir_hook_t hook,
+ void *hook_data)
+{
+ grub_uint64_t offset = 0, file_size;
+ grub_uint32_t blocksz = erofs_blocksz (dir->data);
+ grub_uint8_t *buf;
+ grub_err_t err;
+
+ if (dir->inode_loaded == false)
+ {
+ err = erofs_read_inode (dir->data, dir);
+ if (err != GRUB_ERR_NONE)
+ return 0;
+ }
+
+ file_size = erofs_inode_file_size (dir);
+ buf = grub_malloc (blocksz);
+ if (buf == NULL)
+ return 0;
+
+ while (offset < file_size)
+ {
+ grub_uint64_t maxsize = grub_min (blocksz, file_size - offset);
+ struct grub_erofs_dirent *de = (void *) buf, *end;
+ grub_uint16_t nameoff;
+
+ err = erofs_read_raw_data (dir, buf, maxsize, offset, NULL);
+ if (err != GRUB_ERR_NONE)
+ goto not_found;
+
+ nameoff = grub_le_to_cpu16 (de->nameoff);
+ if (nameoff < sizeof (struct grub_erofs_dirent) || nameoff >= maxsize)
+ {
+ grub_error (GRUB_ERR_BAD_FS,
+ "invalid nameoff %u @ inode %" PRIuGRUB_UINT64_T,
+ nameoff, dir->ino);
+ goto not_found;
+ }
+
+ end = (struct grub_erofs_dirent *) ((grub_uint8_t *) de + nameoff);
+ while (de < end)
+ {
+ struct grub_fshelp_node *fdiro;
+ enum grub_fshelp_filetype type;
+ char filename[EROFS_NAME_LEN + 1];
+ grub_size_t de_namelen;
+ const char *de_name;
+
+ fdiro = grub_malloc (sizeof (struct grub_fshelp_node));
+ if (fdiro == NULL)
+ goto not_found;
+
+ fdiro->data = dir->data;
+ fdiro->ino = grub_le_to_cpu64 (de->nid);
+ fdiro->inode_loaded = false;
+
+ nameoff = grub_le_to_cpu16 (de->nameoff);
+ if (nameoff < sizeof (struct grub_erofs_dirent) || nameoff >= maxsize)
+ {
+ grub_error (GRUB_ERR_BAD_FS,
+ "invalid nameoff %u @ inode %" PRIuGRUB_UINT64_T,
+ nameoff, dir->ino);
+ grub_free (fdiro);
+ goto not_found;
+ }
+
+ de_name = (char *) buf + nameoff;
+ if (de + 1 >= end)
+ de_namelen = grub_erofs_strnlen (de_name, maxsize - nameoff);
+ else
+ {
+ if (grub_sub (grub_le_to_cpu16 (de[1].nameoff), nameoff,
&de_namelen))
+ {
+ grub_error (GRUB_ERR_OUT_OF_RANGE, "de_namelen underflow");
+ grub_free (fdiro);
+ goto not_found;
+ }
+ }
+
+ if (nameoff + de_namelen > maxsize || de_namelen > EROFS_NAME_LEN)
+ {
+ grub_error (GRUB_ERR_BAD_FS,
+ "invalid de_namelen %" PRIuGRUB_SIZE
+ " @ inode %" PRIuGRUB_UINT64_T,
+ de_namelen, dir->ino);
+ grub_free (fdiro);
+ goto not_found;
+ }
+
+ grub_memcpy (filename, de_name, de_namelen);
+ filename[de_namelen] = '\0';
+
+ switch (grub_le_to_cpu16 (de->file_type))
+ {
+ case EROFS_FT_REG_FILE:
+ case EROFS_FT_BLKDEV:
+ case EROFS_FT_CHRDEV:
+ case EROFS_FT_FIFO:
+ case EROFS_FT_SOCK:
+ type = GRUB_FSHELP_REG;
+ break;
+ case EROFS_FT_DIR:
+ type = GRUB_FSHELP_DIR;
+ break;
+ case EROFS_FT_SYMLINK:
+ type = GRUB_FSHELP_SYMLINK;
+ break;
+ case EROFS_FT_UNKNOWN:
+ default:
+ type = GRUB_FSHELP_UNKNOWN;
+ }
+
+ if (hook (filename, type, fdiro, hook_data))
+ {
+ grub_free (buf);
+ return 1;
+ }
+
+ ++de;
+ }
+
+ offset += maxsize;
+ }
+
+ not_found:
+ grub_free (buf);
+ return 0;
+}
+
+static char *
+erofs_read_symlink (grub_fshelp_node_t node)
+{
+ char *symlink;
+ grub_size_t sz;
+ grub_err_t err;
+
+ if (node->inode_loaded == false)
+ {
+ err = erofs_read_inode (node->data, node);
+ if (err != GRUB_ERR_NONE)
+ return NULL;
+ }
+
+ sz = erofs_inode_file_size (node);
+ if (sz >= EROFS_PATH_LEN)
+ {
+ grub_error (GRUB_ERR_BAD_FS,
+ "symlink too long @ inode %" PRIuGRUB_UINT64_T, node->ino);
+ return NULL;
+ }
+
+ symlink = grub_malloc (sz + 1);
+ if (symlink == NULL)
+ return NULL;
+
+ err = erofs_read_raw_data (node, (grub_uint8_t *) symlink, sz, 0, NULL);
+ if (err != GRUB_ERR_NONE)
+ {
+ grub_free (symlink);
+ return NULL;
+ }
+
+ symlink[sz] = '\0';
+ return symlink;
+}
+
+static struct grub_erofs_data *
+erofs_mount (grub_disk_t disk, bool read_root)
+{
+ struct grub_erofs_super sb;
+ grub_err_t err;
+ struct grub_erofs_data *data;
+ grub_uint32_t feature;
+
+ err = grub_disk_read (disk, EROFS_SUPER_OFFSET >> GRUB_DISK_SECTOR_BITS, 0,
+ sizeof (sb), &sb);
+ if (err != GRUB_ERR_NONE)
+ return NULL;
+ if (sb.magic != grub_cpu_to_le32_compile_time (EROFS_MAGIC) ||
+ grub_le_to_cpu32 (sb.log2_blksz) < EROFS_MIN_LOG2_BLOCK_SIZE ||
+ grub_le_to_cpu32 (sb.log2_blksz) > EROFS_MAX_LOG2_BLOCK_SIZE)
+ {
+ grub_error (GRUB_ERR_BAD_FS, "not a valid erofs filesystem");
+ return NULL;
+ }
+
+ feature = grub_le_to_cpu32 (sb.feature_incompat);
+ if (feature & ~EROFS_ALL_FEATURE_INCOMPAT)
+ {
+ grub_error (GRUB_ERR_BAD_FS, "unsupported features: 0x%x",
+ feature & ~EROFS_ALL_FEATURE_INCOMPAT);
+ return NULL;
+ }
+
+ data = grub_malloc (sizeof (*data));
+ if (data == NULL)
+ return NULL;
+
+ data->disk = disk;
+ data->sb = sb;
+
+ if (read_root)
+ {
+ data->inode.data = data;
+ data->inode.ino = grub_le_to_cpu16 (sb.root_nid);
+ err = erofs_read_inode (data, &data->inode);
+ if (err != GRUB_ERR_NONE)
+ {
+ grub_free (data);
+ return NULL;
+ }
+ }
+
+ return data;
+}
+
+/* Context for grub_erofs_dir. */
+struct grub_erofs_dir_ctx
+{
+ grub_fs_dir_hook_t hook;
+ void *hook_data;
+ struct grub_erofs_data *data;
+};
+
+/* Helper for grub_erofs_dir. */
+static int
+erofs_dir_iter (const char *filename, enum grub_fshelp_filetype filetype,
+ grub_fshelp_node_t node, void *data)
+{
+ struct grub_erofs_dir_ctx *ctx = data;
+ struct grub_dirhook_info info = {0};
+ grub_err_t err;
+
+ if (node->inode_loaded == false)
+ {
+ err = erofs_read_inode (ctx->data, node);
+ if (err != GRUB_ERR_NONE)
+ return 0;
+ }
+
+ if (node->inode_loaded == true)
+ {
+ info.mtimeset = 1;
+ info.mtime = erofs_inode_mtime (node);
+ }
+
+ info.dir = ((filetype & GRUB_FSHELP_TYPE_MASK) == GRUB_FSHELP_DIR);
+ grub_free (node);
+ return ctx->hook (filename, &info, ctx->hook_data);
+}
+
+static grub_err_t
+grub_erofs_dir (grub_device_t device, const char *path, grub_fs_dir_hook_t
hook,
+ void *hook_data)
+{
+ grub_fshelp_node_t fdiro = NULL;
+ grub_err_t err;
+ struct grub_erofs_dir_ctx ctx = {
+ .hook = hook,
+ .hook_data = hook_data
+ };
+
+ ctx.data = erofs_mount (device->disk, true);
+ if (ctx.data == NULL)
+ goto fail;
+
+ err = grub_fshelp_find_file (path, &ctx.data->inode, &fdiro,
erofs_iterate_dir,
+ erofs_read_symlink, GRUB_FSHELP_DIR);
+ if (err != GRUB_ERR_NONE)
+ goto fail;
+
+ erofs_iterate_dir (fdiro, erofs_dir_iter, &ctx);
+
+ fail:
+ if (fdiro != &ctx.data->inode)
+ grub_free (fdiro);
+ grub_free (ctx.data);
+
+ return grub_errno;
+}
+
+static grub_err_t
+grub_erofs_open (grub_file_t file, const char *name)
+{
+ struct grub_erofs_data *data;
+ struct grub_fshelp_node *fdiro = NULL;
+ grub_err_t err;
+
+ data = erofs_mount (file->device->disk, true);
+ if (data == NULL)
+ {
+ err = grub_errno;
+ goto fail;
+ }
+
+ err = grub_fshelp_find_file (name, &data->inode, &fdiro, erofs_iterate_dir,
+ erofs_read_symlink, GRUB_FSHELP_REG);
+ if (err != GRUB_ERR_NONE)
+ goto fail;
+
+ if (fdiro->inode_loaded == false)
+ {
+ err = erofs_read_inode (data, fdiro);
+ if (err != GRUB_ERR_NONE)
+ goto fail;
+ }
+
+ grub_memcpy (&data->inode, fdiro, sizeof (*fdiro));
+ grub_free (fdiro);
+
+ file->data = data;
+ file->size = erofs_inode_file_size (&data->inode);
+
+ return GRUB_ERR_NONE;
+
+ fail:
+ if (fdiro != &data->inode)
+ grub_free (fdiro);
+ grub_free (data);
+
+ return err;
+}
+
+static grub_ssize_t
+grub_erofs_read (grub_file_t file, char *buf, grub_size_t len)
+{
+ struct grub_erofs_data *data = file->data;
+ struct grub_fshelp_node *inode = &data->inode;
+ grub_off_t off = file->offset;
+ grub_uint64_t ret = 0, file_size;
+ grub_err_t err;
+
+ if (inode->inode_loaded == false)
+ {
+ err = erofs_read_inode (data, inode);
+ if (err != GRUB_ERR_NONE)
+ return -1;
+ }
+
+ file_size = erofs_inode_file_size (inode);
+
+ if (off > file_size)
+ {
+ grub_error (GRUB_ERR_IO, "read past EOF @ inode %" PRIuGRUB_UINT64_T,
inode->ino);
+ return -1;
+ }
+ if (off == file_size)
+ return 0;
+
+ if (off + len > file_size)
+ len = file_size - off;
+
+ err = erofs_read_raw_data (inode, (grub_uint8_t *) buf, len, off, &ret);
+ if (err != GRUB_ERR_NONE)
+ return -1;
+
+ return ret;
+}
+
+static grub_err_t
+grub_erofs_close (grub_file_t file)
+{
+ grub_free (file->data);
+
+ return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+grub_erofs_uuid (grub_device_t device, char **uuid)
+{
+ struct grub_erofs_data *data;
+
+ data = erofs_mount (device->disk, false);
+ if (data == NULL)
+ {
+ *uuid = NULL;
+ return grub_errno;
+ }
+
+ *uuid = grub_xasprintf ("%pG", &data->sb.uuid);
+
+ grub_free (data);
+
+ return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+grub_erofs_label (grub_device_t device, char **label)
+{
+ struct grub_erofs_data *data;
+
+ data = erofs_mount (device->disk, false);
+ if (data == NULL)
+ {
+ *label = NULL;
+ return grub_errno;
+ }
+
+ *label = grub_strndup ((char *) data->sb.volume_name, sizeof
(data->sb.volume_name));
+ grub_free (data);
+
+ if (*label == NULL)
+ return grub_errno;
+ return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+grub_erofs_mtime (grub_device_t device, grub_int64_t *tm)
+{
+ struct grub_erofs_data *data;
+
+ data = erofs_mount (device->disk, false);
+ if (data == NULL)
+ {
+ *tm = 0;
+ return grub_errno;
+ }
+
+ *tm = grub_le_to_cpu64 (data->sb.build_time);
+
+ grub_free (data);
+
+ return GRUB_ERR_NONE;
+}
+
+static struct grub_fs grub_erofs_fs = {
+ .name = "erofs",
+ .fs_dir = grub_erofs_dir,
+ .fs_open = grub_erofs_open,
+ .fs_read = grub_erofs_read,
+ .fs_close = grub_erofs_close,
+ .fs_uuid = grub_erofs_uuid,
+ .fs_label = grub_erofs_label,
+ .fs_mtime = grub_erofs_mtime,
+#ifdef GRUB_UTIL
+ .reserved_first_sector = 1,
+ .blocklist_install = 0,
+#endif
+ .next = 0,
+};
+
+GRUB_MOD_INIT (erofs)
+{
+ grub_fs_register (&grub_erofs_fs);
+}
+
+GRUB_MOD_FINI (erofs)
+{
+ grub_fs_unregister (&grub_erofs_fs);
+}
--
2.39.3