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Re: [PATCH v2 1/2] fs/erofs: Add support for EROFS
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From: |
Glenn Washburn |
|
Subject: |
Re: [PATCH v2 1/2] fs/erofs: Add support for EROFS |
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Date: |
Thu, 20 Jul 2023 12:19:50 -0500 |
Found one more stylistic change. Other than that this looks reasonable
for inclusion.
Reviewed-by: Glenn Washburn <development@efficientek.com>
Glenn
On Thu, 20 Jul 2023 21:37:48 +0800
Yifan Zhao <zhaoyifan@sjtu.edu.cn> wrote:
> EROFS is a lightweight read-only filesystem designed for performance which
> has already been 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 support will be developed later since it has more work
> to polish.
>
> Signed-off-by: Yifan Zhao <zhaoyifan@sjtu.edu.cn>
> ---
> The link here shows how to boot the kernel from the EROFS partition with this
> patch.
> https://precious-celery-715.notion.site/Demo-of-booting-kernel-in-a-EROFS-partition-c6d199f937a2489bafd03d3083c294b5
>
> INSTALL | 8 +-
> Makefile.util.def | 1 +
> docs/grub.texi | 3 +-
> grub-core/Makefile.core.def | 5 +
> grub-core/fs/erofs.c | 976 ++++++++++++++++++++++++++++++++++++
> grub-core/kern/misc.c | 14 +
> include/grub/misc.h | 1 +
> 7 files changed, 1003 insertions(+), 5 deletions(-)
> create mode 100644 grub-core/fs/erofs.c
>
> diff --git a/INSTALL b/INSTALL
> index b93fe9c61..1939e4745 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, erofs_utils, e2fsprogs, 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 1e9a13d3e..ca2a32a7f 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 b81267980..60c98e931 100644
> --- a/docs/grub.texi
> +++ b/docs/grub.texi
> @@ -361,6 +361,7 @@ 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),
> @@ -6212,7 +6213,7 @@ 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 d2cf29584..eccf9b6cf 100644
> --- a/grub-core/Makefile.core.def
> +++ b/grub-core/Makefile.core.def
> @@ -1438,6 +1438,11 @@ 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..6552a3fdc
> --- /dev/null
> +++ b/grub-core/fs/erofs.c
> @@ -0,0 +1,976 @@
> +/* erofs.c - Enhanced Read-Only File System */
> +/*
> + * GRUB -- GRand Unified Bootloader
> + * Copyright (C) 2023 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_uint8_t uuid[16];
> + 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
> +
> +enum
> +{
> + EROFS_INODE_FLAT_PLAIN = 0,
> + EROFS_INODE_COMPRESSED_FULL = 1,
> + EROFS_INODE_FLAT_INLINE = 2,
> + EROFS_INODE_COMPRESSED_COMPACT = 3,
> + EROFS_INODE_CHUNK_BASED = 4,
> + EROFS_INODE_DATALAYOUT_MAX
> +};
> +
> +#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_NULL_ADDR -1
> +
> +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;
> +
> +enum
> +{
> + EROFS_FT_UNKNOWN,
> + EROFS_FT_REG_FILE,
> + EROFS_FT_DIR,
> + EROFS_FT_CHRDEV,
> + EROFS_FT_BLKDEV,
> + EROFS_FT_FIFO,
> + EROFS_FT_SOCK,
> + EROFS_FT_SYMLINK,
> + EROFS_FT_MAX
> +};
> +
> +#define EROFS_NAME_LEN 255
> +
> +struct grub_erofs_dirent
> +{
> + grub_uint64_t nid;
> + grub_uint16_t nameoff;
> + grub_uint8_t file_type;
> + grub_uint8_t reserved;
> +} GRUB_PACKED;
> +
> +enum
> +{
> + BH_Meta,
> + BH_Mapped,
> +};
> +
> +#define EROFS_MAP_MAPPED (1 << BH_Mapped)
> +
> +struct grub_erofs_map_blocks
> +{
> + grub_off_t m_pa, m_la;
> + grub_off_t m_plen, m_llen;
> + 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;
> + struct grub_erofs_inode_extended 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_read;
> +};
> +
> +struct grub_erofs_data
> +{
> + grub_disk_t disk;
> + struct grub_erofs_super sb;
> +
> + struct grub_fshelp_node inode;
> +};
> +
> +#define erofs_blocksz(data) (1u << data->sb.log2_blksz)
> +
> +static inline grub_uint64_t
> +erofs_iloc (grub_fshelp_node_t node)
> +{
> + struct grub_erofs_super *sb = &node->data->sb;
> +
> + return (grub_le_to_cpu32 (sb->meta_blkaddr) << sb->log2_blksz) +
> + (node->ino << EROFS_ISLOTBITS);
> +}
> +
> +static grub_err_t
> +grub_erofs_read_inode (struct grub_erofs_data *data, grub_fshelp_node_t node)
> +{
> + struct grub_erofs_inode_compact *dic;
> + grub_err_t err;
> + grub_uint64_t addr = erofs_iloc (node);
> +
> + dic = (struct grub_erofs_inode_compact *) &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), dic);
> + if (err)
> + return err;
> +
> + node->inode_type =
> + (dic->i_format >> EROFS_I_VERSION_BIT) & EROFS_I_VERSION_MASKS;
> + node->inode_datalayout =
> + (dic->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),
> + (char *) dic + sizeof (struct grub_erofs_inode_compact));
> + if (err)
> + return err;
> + break;
> + case EROFS_INODE_LAYOUT_COMPACT:
> + break;
> + default:
> + return grub_error (GRUB_ERR_BAD_FS,
> + "invalid inode version %u @ inode %" PRIuGRUB_UINT64_T,
> + node->inode_type, node->ino);
> + }
> +
> + node->inode_read = true;
> +
> + return 0;
> +}
> +
> +static inline 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 inline grub_uint64_t
> +erofs_inode_file_size (grub_fshelp_node_t node)
> +{
> + struct grub_erofs_inode_compact *dic =
> + (struct grub_erofs_inode_compact *) &node->inode;
> +
> + return node->inode_type == EROFS_INODE_LAYOUT_COMPACT
> + ? grub_le_to_cpu32 (dic->i_size)
> + : grub_le_to_cpu64 (node->inode.i_size);
> +}
> +
> +static inline grub_uint32_t
> +erofs_inode_xattr_ibody_size (grub_fshelp_node_t node)
> +{
> + grub_uint16_t cnt = grub_le_to_cpu16 (node->inode.i_xattr_icount);
> +
> + return cnt ? sizeof (struct grub_erofs_xattr_ibody_header) +
> + (cnt - 1) * sizeof (grub_uint32_t)
> + : 0;
> +}
> +
> +static inline 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.i_mtime);
> +}
> +
> +static grub_err_t
> +grub_erofs_map_blocks_flatmode (grub_fshelp_node_t node,
> + struct grub_erofs_map_blocks *map)
> +{
> + grub_off_t nblocks, lastblk, file_size;
> + grub_off_t tailendpacking =
> + (node->inode_datalayout == EROFS_INODE_FLAT_INLINE) ? 1 : 0;
> + grub_uint32_t blocksz = erofs_blocksz (node->data);
> +
> + file_size = erofs_inode_file_size (node);
> + nblocks = (file_size + blocksz - 1) >> node->data->sb.log2_blksz;
> + lastblk = nblocks - tailendpacking;
> +
> + map->m_flags = EROFS_MAP_MAPPED;
> +
> + if (map->m_la < (lastblk * blocksz))
> + {
> + map->m_pa =
> + grub_le_to_cpu32 (node->inode.i_u.raw_blkaddr) * blocksz + map->m_la;
> + map->m_plen = lastblk * blocksz - map->m_la;
> + }
> + else if (tailendpacking)
> + {
> + map->m_pa = erofs_iloc (node) + erofs_inode_size (node) +
> + erofs_inode_xattr_ibody_size (node) + (map->m_la % blocksz);
> + map->m_plen = file_size - map->m_la;
> +
> + 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
> +grub_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.i_u.c.format);
> + grub_off_t unit, pos;
> + grub_uint64_t chunknr;
> + 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);
> +
> + chunknr = map->m_la >> chunkbits;
> + pos = ALIGN_UP (erofs_iloc (node) + erofs_inode_size (node) +
> + erofs_inode_xattr_ibody_size (node),
> + unit);
> + pos += chunknr * unit;
> +
> + map->m_la = chunknr << chunkbits;
> + map->m_plen = grub_min (1ULL << chunkbits,
> + ALIGN_UP (erofs_inode_file_size (node) - map->m_la,
> + erofs_blocksz (node->data)));
> +
> + if (chunk_format & EROFS_CHUNK_FORMAT_INDEXES)
> + {
> + struct grub_erofs_inode_chunk_index idx;
> + grub_uint32_t blkaddr;
> +
> + err = grub_disk_read (node->data->disk, pos >> GRUB_DISK_SECTOR_BITS,
> + pos & (GRUB_DISK_SECTOR_SIZE - 1), unit, &idx);
> + if (err)
> + return err;
> +
> + blkaddr = grub_le_to_cpu32 (idx.blkaddr);
> +
> + if (blkaddr == (grub_uint32_t) 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;
> + }
> + }
> + else
> + {
> + grub_uint32_t blkaddr_le, blkaddr;
> +
> + err =
> + grub_disk_read (node->data->disk, pos >> GRUB_DISK_SECTOR_BITS,
> + pos & (GRUB_DISK_SECTOR_SIZE - 1), unit, &blkaddr_le);
> + if (err)
> + return err;
> +
> + blkaddr = grub_le_to_cpu32 (blkaddr_le);
> + if (blkaddr == (grub_uint32_t) 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
> +grub_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 grub_erofs_map_blocks_flatmode (node, map);
> + else
> + return grub_erofs_map_blocks_chunkmode (node, map);
> +}
> +
> +static grub_err_t
> +grub_erofs_read_raw_data (grub_fshelp_node_t node, char *buf, grub_off_t
> size,
> + grub_off_t offset, grub_off_t *bytes)
> +{
> + struct grub_erofs_map_blocks map;
> + grub_err_t err;
> +
> + if (bytes)
> + *bytes = 0;
> +
> + if (!node->inode_read)
> + {
> + err = grub_erofs_read_inode (node->data, node);
> + if (err)
> + return err;
> + }
> +
> + grub_memset (&map, 0, sizeof (map));
> +
> + grub_off_t cur = offset;
> + while (cur < offset + size)
> + {
> + char *const estart = buf + cur - offset;
> + grub_off_t eend, moff = 0;
> +
> + map.m_la = cur;
> + err = grub_erofs_map_blocks (node, &map);
> + if (err)
> + return err;
> +
> + eend = grub_min (offset + size, map.m_la + map.m_llen);
> + if (!(map.m_flags & EROFS_MAP_MAPPED))
> + {
> + if (!map.m_llen)
> + {
> + /* reached EOF */
> + grub_memset (estart, 0, offset + size - cur);
> + cur = offset + size;
> + continue;
> + }
> +
> + /* Hole */
> + grub_memset (estart, 0, eend - cur);
> + cur = eend;
> + if (bytes)
> + *bytes += eend - cur;
> + 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)
> + return err;
> +
> + if (bytes)
> + *bytes += eend - map.m_la;
> +
> + cur = eend;
> + }
> +
> + return GRUB_ERR_NONE;
> +}
> +
> +static int
> +grub_erofs_iterate_dir (grub_fshelp_node_t dir,
> + grub_fshelp_iterate_dir_hook_t hook, void *hook_data)
> +{
> + grub_off_t offset = 0, file_size;
> + grub_err_t err;
> + grub_uint32_t blocksz = erofs_blocksz (dir->data);
> + char *buf;
> +
> + if (!dir->inode_read)
> + {
> + err = grub_erofs_read_inode (dir->data, dir);
> + if (err)
> + return 0;
> + }
> +
> + file_size = erofs_inode_file_size (dir);
> + buf = grub_malloc (blocksz);
> + if (!buf)
> + {
> + grub_error (GRUB_ERR_OUT_OF_MEMORY, "out of memory");
> + return 0;
> + }
> +
> + while (offset < file_size)
> + {
> + grub_off_t maxsize = grub_min (blocksz, file_size - offset);
> + struct grub_erofs_dirent *de = (void *) buf, *end;
> + grub_uint16_t nameoff;
> +
> + err = grub_erofs_read_raw_data (dir, buf, maxsize, offset, NULL);
> + if (err)
> + goto not_found;
> +
> + nameoff = grub_le_to_cpu16 (de->nameoff);
> + if (nameoff < sizeof (struct grub_erofs_dirent) || nameoff > blocksz)
> + {
> + grub_error (GRUB_ERR_BAD_FS,
> + "invalid de[0].nameoff %u @ inode %" PRIuGRUB_UINT64_T,
> + nameoff, dir->ino);
> + goto not_found;
> + }
> +
> + end = (struct grub_erofs_dirent *) ((char *) de + nameoff);
> + while (de < end)
> + {
> + struct grub_fshelp_node *fdiro;
> + enum grub_fshelp_filetype type;
> + char filename[EROFS_NAME_LEN + 1];
> + unsigned int de_namelen;
> + const char *de_name;
> +
> + fdiro = grub_malloc (sizeof (struct grub_fshelp_node));
> + if (!fdiro)
> + {
> + grub_error (GRUB_ERR_OUT_OF_MEMORY, "out of memory");
> + goto not_found;
> + }
> +
> + fdiro->data = dir->data;
> + fdiro->ino = grub_le_to_cpu64 (de->nid);
> + fdiro->inode_read = false;
> +
> + nameoff = grub_le_to_cpu16 (de->nameoff);
> + de_name = buf + nameoff;
> + if (de + 1 >= end)
> + de_namelen = grub_strnlen (de_name, maxsize - nameoff);
> + else
> + de_namelen = grub_le_to_cpu16 (de[1].nameoff) - nameoff;
> +
> + 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;
> + break;
> + }
> +
> + if (hook (filename, type, fdiro, hook_data))
> + {
> + grub_free (buf);
> + return 1;
> + }
> +
> + ++de;
> + }
> +
> + offset += maxsize;
> + }
> +
> +not_found:
> + grub_free (buf);
> + return 0;
> +}
> +
> +static char *
> +grub_erofs_read_symlink (grub_fshelp_node_t node)
> +{
> + char *symlink;
> + grub_size_t sz;
> +
> + if (!node->inode_read)
> + {
> + grub_erofs_read_inode (node->data, node);
> + if (grub_errno)
> + {
Unneeded brace.
Glenn
> + return NULL;
> + }
> + }
> +
> + if (grub_add (erofs_inode_file_size (node), 1, &sz))
> + {
> + grub_error (GRUB_ERR_OUT_OF_RANGE, N_ ("overflow is detected"));
> + return NULL;
> + }
> +
> + symlink = grub_malloc (sz);
> + if (!symlink)
> + return NULL;
> +
> + grub_erofs_read_raw_data (node, symlink, sz - 1, 0, NULL);
> + if (grub_errno)
> + {
> + grub_free (symlink);
> + return NULL;
> + }
> +
> + symlink[sz - 1] = '\0';
> + return symlink;
> +}
> +
> +static struct grub_erofs_data *
> +grub_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 (grub_errno == GRUB_ERR_OUT_OF_RANGE)
> + grub_error (GRUB_ERR_BAD_FS, "not a valid erofs filesystem");
> + if (err)
> + return NULL;
> + if (sb.magic != grub_cpu_to_le32_compile_time (EROFS_MAGIC))
> + {
> + 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)
> + {
> + grub_error (GRUB_ERR_OUT_OF_MEMORY, "out of memory");
> + 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 = grub_erofs_read_inode (data, &data->inode);
> + if (err)
> + {
> + 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
> +grub_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;
> +
> + grub_memset (&info, 0, sizeof (info));
> + if (!node->inode_read)
> + {
> + grub_erofs_read_inode (ctx->data, node);
> + grub_errno = GRUB_ERR_NONE;
> + }
> +
> + if (node->inode_read)
> + {
> + 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;
> + struct grub_erofs_dir_ctx ctx = {
> + .hook = hook,
> + .hook_data = hook_data,
> + };
> +
> + ctx.data = grub_erofs_mount (device->disk, true);
> + if (!ctx.data)
> + goto fail;
> +
> + grub_fshelp_find_file (path, &ctx.data->inode, &fdiro,
> grub_erofs_iterate_dir,
> + grub_erofs_read_symlink, GRUB_FSHELP_DIR);
> + if (grub_errno)
> + goto fail;
> +
> + grub_erofs_iterate_dir (fdiro, grub_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 = 0;
> + grub_err_t err;
> +
> + data = grub_erofs_mount (file->device->disk, true);
> + if (!data)
> + {
> + err = grub_errno;
> + goto fail;
> + }
> +
> + err =
> + grub_fshelp_find_file (name, &data->inode, &fdiro,
> grub_erofs_iterate_dir,
> + grub_erofs_read_symlink, GRUB_FSHELP_REG);
> + if (err)
> + goto fail;
> +
> + if (!fdiro->inode_read)
> + {
> + err = grub_erofs_read_inode (data, fdiro);
> + if (err)
> + 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, ret = 0;
> + grub_off_t file_size;
> +
> + if (!inode->inode_read)
> + {
> + grub_erofs_read_inode (data, inode);
> + if (grub_errno)
> + {
> + ret = 0;
> + grub_error (GRUB_ERR_IO, "cannot read @ inode %" PRIuGRUB_UINT64_T,
> + inode->ino);
> + goto end;
> + }
> + }
> +
> + file_size = erofs_inode_file_size (inode);
> +
> + if (off >= file_size)
> + goto end;
> +
> + if (off + len > file_size)
> + len = file_size - off;
> +
> + grub_erofs_read_raw_data (inode, buf, len, off, &ret);
> + if (grub_errno)
> + {
> + ret = 0;
> + grub_error (GRUB_ERR_IO, "cannot read file @ inode %"
> PRIuGRUB_UINT64_T,
> + inode->ino);
> + goto end;
> + }
> +
> +end:
> + 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;
> +
> + grub_errno = GRUB_ERR_NONE;
> + data = grub_erofs_mount (device->disk, false);
> +
> + if (data)
> + *uuid = grub_xasprintf (
> + "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%"
> + "02x",
> + data->sb.uuid[0], data->sb.uuid[1], data->sb.uuid[2], data->sb.uuid[3],
> + data->sb.uuid[4], data->sb.uuid[5], data->sb.uuid[6], data->sb.uuid[7],
> + data->sb.uuid[8], data->sb.uuid[9], data->sb.uuid[10],
> + data->sb.uuid[11], data->sb.uuid[12], data->sb.uuid[13],
> + data->sb.uuid[14], data->sb.uuid[15]);
> + else
> + *uuid = NULL;
> +
> + grub_free (data);
> +
> + return grub_errno;
> +}
> +
> +static grub_err_t
> +grub_erofs_label (grub_device_t device, char **label)
> +{
> + struct grub_erofs_data *data;
> +
> + grub_errno = GRUB_ERR_NONE;
> + data = grub_erofs_mount (device->disk, false);
> +
> + if (data)
> + *label = grub_strndup ((char *) data->sb.volume_name,
> + sizeof (data->sb.volume_name));
> + else
> + *label = NULL;
> +
> + grub_free (data);
> +
> + return grub_errno;
> +}
> +
> +static grub_err_t
> +grub_erofs_mtime (grub_device_t device, grub_int64_t *tm)
> +{
> + struct grub_erofs_data *data;
> +
> + grub_errno = GRUB_ERR_NONE;
> + data = grub_erofs_mount (device->disk, false);
> +
> + if (!data)
> + *tm = 0;
> + else
> + *tm = grub_le_to_cpu64 (data->sb.build_time);
> +
> + grub_free (data);
> +
> + return grub_errno;
> +}
> +
> +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);
> +}
> \ No newline at end of file
> diff --git a/grub-core/kern/misc.c b/grub-core/kern/misc.c
> index 2890aad49..66cbb3c5c 100644
> --- a/grub-core/kern/misc.c
> +++ b/grub-core/kern/misc.c
> @@ -594,6 +594,20 @@ grub_strlen (const char *s)
> return p - s;
> }
>
> +grub_size_t
> +grub_strnlen (const char *s, grub_size_t n)
> +{
> + const char *p = s;
> +
> + if (n == 0)
> + return 0;
> +
> + while (*p && n--)
> + p++;
> +
> + return p - s;
> +}
> +
> static inline void
> grub_reverse (char *str)
> {
> diff --git a/include/grub/misc.h b/include/grub/misc.h
> index 1b35a167f..eb4aa55c1 100644
> --- a/include/grub/misc.h
> +++ b/include/grub/misc.h
> @@ -335,6 +335,7 @@ char *EXPORT_FUNC(grub_strdup) (const char *s)
> WARN_UNUSED_RESULT;
> char *EXPORT_FUNC(grub_strndup) (const char *s, grub_size_t n)
> WARN_UNUSED_RESULT;
> void *EXPORT_FUNC(grub_memset) (void *s, int c, grub_size_t n);
> grub_size_t EXPORT_FUNC(grub_strlen) (const char *s) WARN_UNUSED_RESULT;
> +grub_size_t EXPORT_FUNC(grub_strnlen) (const char *s, grub_size_t n)
> WARN_UNUSED_RESULT;
>
> /* Replace all `ch' characters of `input' with `with' and copy the
> result into `output'; return EOS address of `output'. */