fs/squashfs: new filesystem

Add support for SquashFS filesystem. Right now, it does not support
compression but support for zlib will be added in a follow-up commit.

Signed-off-by: Joao Marcos Costa <joaomarcos.costa@bootlin.com>
This commit is contained in:
Joao Marcos Costa 2020-07-30 15:33:47 +02:00 committed by Tom Rini
parent 550a9e7902
commit c510061303
16 changed files with 2297 additions and 0 deletions

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@ -969,6 +969,12 @@ S: Maintained
F: drivers/spmi/
F: include/spmi/
SQUASHFS
M: Joao Marcos Costa <joaomarcos.costa@bootlin.com>
S: Maintained
F: fs/squashfs/
F: include/sqfs.h
TARGET_BCMNS3
M: Bharat Gooty <bharat.gooty@broadcom.com>
M: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>

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@ -577,6 +577,15 @@ config SPL_FS_EXT4
filesystem from within SPL. Support for the underlying block
device (e.g. MMC or USB) must be enabled separately.
config SPL_FS_SQUASHFS
bool "Support SquashFS filesystems"
select FS_SQUASHFS
help
Enable support for SquashFS filesystems with SPL. This permits
U-Boot (or Linux in Falcon mode) to be loaded from a SquashFS
filesystem from within SPL. Support for the underlying block
device (e.g. MMC or USB) must be enabled separately.
config SPL_FS_FAT
bool "Support FAT filesystems"
select FS_FAT

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@ -22,4 +22,6 @@ source "fs/cramfs/Kconfig"
source "fs/yaffs2/Kconfig"
source "fs/squashfs/Kconfig"
endmenu

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@ -9,6 +9,7 @@ obj-$(CONFIG_FS_LOADER) += fs.o
obj-$(CONFIG_SPL_FS_FAT) += fat/
obj-$(CONFIG_SPL_FS_EXT4) += ext4/
obj-$(CONFIG_SPL_FS_CBFS) += cbfs/
obj-$(CONFIG_SPL_FS_SQUASHFS) += squashfs/
else
obj-y += fs.o
@ -23,5 +24,6 @@ obj-$(CONFIG_SANDBOX) += sandbox/
obj-$(CONFIG_CMD_UBIFS) += ubifs/
obj-$(CONFIG_YAFFS2) += yaffs2/
obj-$(CONFIG_CMD_ZFS) += zfs/
obj-$(CONFIG_FS_SQUASHFS) += squashfs/
endif
obj-y += fs_internal.o

15
fs/fs.c
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@ -22,6 +22,7 @@
#include <div64.h>
#include <linux/math64.h>
#include <efi_loader.h>
#include <squashfs.h>
DECLARE_GLOBAL_DATA_PTR;
@ -276,6 +277,20 @@ static struct fstype_info fstypes[] = {
.mkdir = fs_mkdir_unsupported,
.ln = fs_ln_unsupported,
},
#endif
#if IS_ENABLED(CONFIG_FS_SQUASHFS)
{
.fstype = FS_TYPE_SQUASHFS,
.name = "squashfs",
.probe = sqfs_probe,
.opendir = sqfs_opendir,
.readdir = sqfs_readdir,
.ls = fs_ls_generic,
.read = sqfs_read,
.size = sqfs_size,
.close = sqfs_close,
.closedir = sqfs_closedir,
},
#endif
{
.fstype = FS_TYPE_ANY,

10
fs/squashfs/Kconfig Normal file
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@ -0,0 +1,10 @@
config FS_SQUASHFS
bool "Enable SquashFS filesystem support"
help
This provides support for reading images from SquashFS filesystem.
Squashfs is a compressed read-only filesystem for Linux.
It uses zlib, lz4, lzo, or xz compression to compress files, inodes
and directories. Squashfs is intended for general read-only
filesystem use, for archival use (i.e. in cases where a .tar.gz file
may be used), and in constrained block device/memory systems (e.g.
embedded systems) where low overhead is needed.

7
fs/squashfs/Makefile Normal file
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@ -0,0 +1,7 @@
# SPDX-License-Identifier: GPL-2.0+
#
obj-$(CONFIG_$(SPL_)FS_SQUASHFS) = sqfs.o \
sqfs_inode.o \
sqfs_dir.o \
sqfs_decompressor.o

1538
fs/squashfs/sqfs.c Normal file

File diff suppressed because it is too large Load diff

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@ -0,0 +1,29 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020 Bootlin
*
* Author: Joao Marcos Costa <joaomarcos.costa@bootlin.com>
*/
#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include "sqfs_decompressor.h"
#include "sqfs_filesystem.h"
#include "sqfs_utils.h"
int sqfs_decompress(u16 comp_type, void *dest, unsigned long *dest_len,
void *source, u32 lenp)
{
int ret = 0;
switch (comp_type) {
default:
printf("Error: unknown compression type.\n");
return -EINVAL;
}
return ret;
}

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@ -0,0 +1,58 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020 Bootlin
*
* Author: Joao Marcos Costa <joaomarcos.costa@bootlin.com>
*/
#ifndef SQFS_DECOMPRESSOR_H
#define SQFS_DECOMPRESSOR_H
#include <stdint.h>
#define SQFS_COMP_ZLIB 1
#define SQFS_COMP_LZMA 2
#define SQFS_COMP_LZO 3
#define SQFS_COMP_XZ 4
#define SQFS_COMP_LZ4 5
#define SQFS_COMP_ZSTD 6
/* LZMA does not support any compression options */
struct squashfs_gzip_opts {
u32 compression_level;
u16 window_size;
u16 strategies;
};
struct squashfs_xz_opts {
u32 dictionary_size;
u32 executable_filters;
};
struct squashfs_lz4_opts {
u32 version;
u32 flags;
};
struct squashfs_zstd_opts {
u32 compression_level;
};
struct squashfs_lzo_opts {
u32 algorithm;
u32 level;
};
union squashfs_compression_opts {
struct squashfs_gzip_opts *gzip;
struct squashfs_xz_opts *xz;
struct squashfs_lz4_opts *lz4;
struct squashfs_zstd_opts *zstd;
struct squashfs_lzo_opts *lzo;
};
int sqfs_decompress(u16 comp_type, void *dest, unsigned long *dest_len,
void *source, u32 lenp);
#endif /* SQFS_DECOMPRESSOR_H */

91
fs/squashfs/sqfs_dir.c Normal file
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@ -0,0 +1,91 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020 Bootlin
*
* Author: Joao Marcos Costa <joaomarcos.costa@bootlin.com>
*/
#include <errno.h>
#include <linux/types.h>
#include <linux/byteorder/little_endian.h>
#include <linux/byteorder/generic.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include "sqfs_filesystem.h"
#include "sqfs_utils.h"
bool sqfs_is_dir(u16 type)
{
return type == SQFS_DIR_TYPE || type == SQFS_LDIR_TYPE;
}
/*
* Receives a pointer (void *) to a position in the inode table containing the
* directory's inode. Returns directory inode offset into the directory table.
* m_list contains each metadata block's position, and m_count is the number of
* elements of m_list. Those metadata blocks come from the compressed directory
* table.
*/
int sqfs_dir_offset(void *dir_i, u32 *m_list, int m_count)
{
struct squashfs_base_inode *base = dir_i;
struct squashfs_ldir_inode *ldir;
struct squashfs_dir_inode *dir;
u32 start_block;
u16 offset;
int j;
switch (get_unaligned_le16(&base->inode_type)) {
case SQFS_DIR_TYPE:
dir = (struct squashfs_dir_inode *)base;
start_block = get_unaligned_le32(&dir->start_block);
offset = get_unaligned_le16(&dir->offset);
break;
case SQFS_LDIR_TYPE:
ldir = (struct squashfs_ldir_inode *)base;
start_block = get_unaligned_le32(&ldir->start_block);
offset = get_unaligned_le16(&ldir->offset);
break;
default:
printf("Error: this is not a directory.\n");
return -EINVAL;
}
for (j = 0; j < m_count; j++) {
if (m_list[j] == start_block)
return (++j * SQFS_METADATA_BLOCK_SIZE) + offset;
}
if (start_block == 0)
return offset;
printf("Error: invalid inode reference to directory table.\n");
return -EINVAL;
}
bool sqfs_is_empty_dir(void *dir_i)
{
struct squashfs_base_inode *base = dir_i;
struct squashfs_ldir_inode *ldir;
struct squashfs_dir_inode *dir;
u32 file_size;
switch (get_unaligned_le16(&base->inode_type)) {
case SQFS_DIR_TYPE:
dir = (struct squashfs_dir_inode *)base;
file_size = get_unaligned_le16(&dir->file_size);
break;
case SQFS_LDIR_TYPE:
ldir = (struct squashfs_ldir_inode *)base;
file_size = get_unaligned_le16(&ldir->file_size);
break;
default:
printf("Error: this is not a directory.\n");
return false;
}
return file_size == SQFS_EMPTY_FILE_SIZE;
}

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@ -0,0 +1,300 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020 Bootlin
*
* Author: Joao Marcos Costa <joaomarcos.costa@bootlin.com>
*/
#ifndef SQFS_FILESYSTEM_H
#define SQFS_FILESYSTEM_H
#include <asm/unaligned.h>
#include <stdint.h>
#include <fs.h>
#define SQFS_UNCOMPRESSED_DATA 0x0002
#define SQFS_MAGIC_NUMBER 0x73717368
/* The three first members of squashfs_dir_index make a total of 12 bytes */
#define SQFS_DIR_INDEX_BASE_LENGTH 12
/* size of metadata (inode and directory) blocks */
#define SQFS_METADATA_BLOCK_SIZE 8192
/* Max. number of fragment entries in a metadata block is 512 */
#define SQFS_MAX_ENTRIES 512
/* Metadata blocks start by a 2-byte length header */
#define SQFS_HEADER_SIZE 2
#define SQFS_LREG_INODE_MIN_SIZE 56
#define SQFS_DIR_HEADER_SIZE 12
#define SQFS_MISC_ENTRY_TYPE -1
#define SQFS_EMPTY_FILE_SIZE 3
#define SQFS_STOP_READDIR 1
#define SQFS_EMPTY_DIR -1
/*
* A directory entry object has a fixed length of 8 bytes, corresponding to its
* first four members, plus the size of the entry name, which is equal to
* 'entry_name' + 1 bytes.
*/
#define SQFS_ENTRY_BASE_LENGTH 8
/* Inode types */
#define SQFS_DIR_TYPE 1
#define SQFS_REG_TYPE 2
#define SQFS_SYMLINK_TYPE 3
#define SQFS_BLKDEV_TYPE 4
#define SQFS_CHRDEV_TYPE 5
#define SQFS_FIFO_TYPE 6
#define SQFS_SOCKET_TYPE 7
#define SQFS_LDIR_TYPE 8
#define SQFS_LREG_TYPE 9
#define SQFS_LSYMLINK_TYPE 10
#define SQFS_LBLKDEV_TYPE 11
#define SQFS_LCHRDEV_TYPE 12
#define SQFS_LFIFO_TYPE 13
#define SQFS_LSOCKET_TYPE 14
struct squashfs_super_block {
__le32 s_magic;
__le32 inodes;
__le32 mkfs_time;
__le32 block_size;
__le32 fragments;
__le16 compression;
__le16 block_log;
__le16 flags;
__le16 no_ids;
__le16 s_major;
__le16 s_minor;
__le64 root_inode;
__le64 bytes_used;
__le64 id_table_start;
__le64 xattr_id_table_start;
__le64 inode_table_start;
__le64 directory_table_start;
__le64 fragment_table_start;
__le64 export_table_start;
};
struct squashfs_directory_index {
u32 index;
u32 start;
u32 size;
char name[0];
};
struct squashfs_base_inode {
__le16 inode_type;
__le16 mode;
__le16 uid;
__le16 guid;
__le32 mtime;
__le32 inode_number;
};
struct squashfs_ipc_inode {
__le16 inode_type;
__le16 mode;
__le16 uid;
__le16 guid;
__le32 mtime;
__le32 inode_number;
__le32 nlink;
};
struct squashfs_lipc_inode {
__le16 inode_type;
__le16 mode;
__le16 uid;
__le16 guid;
__le32 mtime;
__le32 inode_number;
__le32 nlink;
__le32 xattr;
};
struct squashfs_dev_inode {
__le16 inode_type;
__le16 mode;
__le16 uid;
__le16 guid;
__le32 mtime;
__le32 inode_number;
__le32 nlink;
__le32 rdev;
};
struct squashfs_ldev_inode {
__le16 inode_type;
__le16 mode;
__le16 uid;
__le16 guid;
__le32 mtime;
__le32 inode_number;
__le32 nlink;
__le32 rdev;
__le32 xattr;
};
struct squashfs_symlink_inode {
__le16 inode_type;
__le16 mode;
__le16 uid;
__le16 guid;
__le32 mtime;
__le32 inode_number;
__le32 nlink;
__le32 symlink_size;
char symlink[0];
};
struct squashfs_reg_inode {
__le16 inode_type;
__le16 mode;
__le16 uid;
__le16 guid;
__le32 mtime;
__le32 inode_number;
__le32 start_block;
__le32 fragment;
__le32 offset;
__le32 file_size;
__le32 block_list[0];
};
struct squashfs_lreg_inode {
__le16 inode_type;
__le16 mode;
__le16 uid;
__le16 guid;
__le32 mtime;
__le32 inode_number;
__le64 start_block;
__le64 file_size;
__le64 sparse;
__le32 nlink;
__le32 fragment;
__le32 offset;
__le32 xattr;
__le32 block_list[0];
};
struct squashfs_dir_inode {
__le16 inode_type;
__le16 mode;
__le16 uid;
__le16 guid;
__le32 mtime;
__le32 inode_number;
__le32 start_block;
__le32 nlink;
__le16 file_size;
__le16 offset;
__le32 parent_inode;
};
struct squashfs_ldir_inode {
__le16 inode_type;
__le16 mode;
__le16 uid;
__le16 guid;
__le32 mtime;
__le32 inode_number;
__le32 nlink;
__le32 file_size;
__le32 start_block;
__le32 parent_inode;
__le16 i_count;
__le16 offset;
__le32 xattr;
struct squashfs_directory_index index[0];
};
union squashfs_inode {
struct squashfs_base_inode *base;
struct squashfs_dev_inode *dev;
struct squashfs_ldev_inode *ldev;
struct squashfs_symlink_inode *symlink;
struct squashfs_reg_inode *reg;
struct squashfs_lreg_inode *lreg;
struct squashfs_dir_inode *dir;
struct squashfs_ldir_inode *ldir;
struct squashfs_ipc_inode *ipc;
struct squashfs_lipc_inode *lipc;
};
struct squashfs_directory_entry {
u16 offset;
u16 inode_offset;
u16 type;
u16 name_size;
char name[0];
};
struct squashfs_directory_header {
u32 count;
u32 start;
u32 inode_number;
};
struct squashfs_fragment_block_entry {
u64 start;
u32 size;
u32 _unused;
};
struct squashfs_dir_stream {
struct fs_dir_stream fs_dirs;
struct fs_dirent dentp;
/*
* 'size' is the uncompressed size of the entire listing, including
* headers. 'entry_count' is the number of entries following a
* specific header. Both variables are decremented in sqfs_readdir() so
* the function knows when the end of the directory is reached.
*/
size_t size;
int entry_count;
/* SquashFS structures */
struct squashfs_directory_header *dir_header;
struct squashfs_directory_entry *entry;
/*
* 'table' points to a position into the directory table. Both 'table'
* and 'inode' are defined for the first time in sqfs_opendir().
* 'table's value changes in sqfs_readdir().
*/
unsigned char *table;
union squashfs_inode i;
struct squashfs_dir_inode i_dir;
struct squashfs_ldir_inode i_ldir;
/*
* References to the tables' beginnings. They are assigned in
* sqfs_opendir() and freed in sqfs_closedir().
*/
unsigned char *inode_table;
unsigned char *dir_table;
};
struct squashfs_file_info {
/* File size in bytes (uncompressed) */
size_t size;
/* Reference to list of data blocks's sizes */
u32 *blk_sizes;
/* Offset into the fragment block */
u32 offset;
/* Offset in which the data blocks begin */
u64 start;
/* Is file fragmented? */
bool frag;
/* Compressed fragment */
bool comp;
};
void *sqfs_find_inode(void *inode_table, int inode_number, __le32 inode_count,
__le32 block_size);
int sqfs_dir_offset(void *dir_i, u32 *m_list, int m_count);
int sqfs_read_metablock(unsigned char *file_mapping, int offset,
bool *compressed, u32 *data_size);
bool sqfs_is_empty_dir(void *dir_i);
bool sqfs_is_dir(u16 type);
#endif /* SQFS_FILESYSTEM_H */

155
fs/squashfs/sqfs_inode.c Normal file
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@ -0,0 +1,155 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020 Bootlin
*
* Author: Joao Marcos Costa <joaomarcos.costa@bootlin.com>
*/
#include <asm/unaligned.h>
#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "sqfs_decompressor.h"
#include "sqfs_filesystem.h"
#include "sqfs_utils.h"
int sqfs_inode_size(struct squashfs_base_inode *inode, u32 blk_size)
{
switch (get_unaligned_le16(&inode->inode_type)) {
case SQFS_DIR_TYPE:
return sizeof(struct squashfs_dir_inode);
case SQFS_REG_TYPE: {
struct squashfs_reg_inode *reg =
(struct squashfs_reg_inode *)inode;
u32 fragment = get_unaligned_le32(&reg->fragment);
u32 file_size = get_unaligned_le32(&reg->file_size);
unsigned int blk_list_size;
if (SQFS_IS_FRAGMENTED(fragment))
blk_list_size = file_size / blk_size;
else
blk_list_size = DIV_ROUND_UP(file_size, blk_size);
return sizeof(*reg) + blk_list_size * sizeof(u32);
}
case SQFS_LDIR_TYPE: {
struct squashfs_ldir_inode *ldir =
(struct squashfs_ldir_inode *)inode;
u16 i_count = get_unaligned_le16(&ldir->i_count);
unsigned int index_list_size = 0, l = 0;
struct squashfs_directory_index *di;
u32 sz;
if (i_count == 0)
return sizeof(*ldir);
di = ldir->index;
while (l < i_count + 1) {
sz = get_unaligned_le32(&di->size) + 1;
index_list_size += sz;
di = (void *)di + sizeof(*di) + sz;
l++;
}
return sizeof(*ldir) + index_list_size +
(i_count + 1) * SQFS_DIR_INDEX_BASE_LENGTH;
}
case SQFS_LREG_TYPE: {
struct squashfs_lreg_inode *lreg =
(struct squashfs_lreg_inode *)inode;
u32 fragment = get_unaligned_le32(&lreg->fragment);
u64 file_size = get_unaligned_le64(&lreg->file_size);
unsigned int blk_list_size;
if (fragment == 0xFFFFFFFF)
blk_list_size = DIV_ROUND_UP(file_size, blk_size);
else
blk_list_size = file_size / blk_size;
return sizeof(*lreg) + blk_list_size * sizeof(u32);
}
case SQFS_SYMLINK_TYPE:
case SQFS_LSYMLINK_TYPE: {
struct squashfs_symlink_inode *symlink =
(struct squashfs_symlink_inode *)inode;
return sizeof(*symlink) +
get_unaligned_le32(&symlink->symlink_size);
}
case SQFS_BLKDEV_TYPE:
case SQFS_CHRDEV_TYPE:
return sizeof(struct squashfs_dev_inode);
case SQFS_LBLKDEV_TYPE:
case SQFS_LCHRDEV_TYPE:
return sizeof(struct squashfs_ldev_inode);
case SQFS_FIFO_TYPE:
case SQFS_SOCKET_TYPE:
return sizeof(struct squashfs_ipc_inode);
case SQFS_LFIFO_TYPE:
case SQFS_LSOCKET_TYPE:
return sizeof(struct squashfs_lipc_inode);
default:
printf("Error while searching inode: unknown type.\n");
return -EINVAL;
}
}
/*
* Given the uncompressed inode table, the inode to be found and the number of
* inodes in the table, return inode position in case of success.
*/
void *sqfs_find_inode(void *inode_table, int inode_number, __le32 inode_count,
__le32 block_size)
{
struct squashfs_base_inode *base;
unsigned int offset = 0, k;
int sz;
if (!inode_table) {
printf("%s: Invalid pointer to inode table.\n", __func__);
return NULL;
}
for (k = 0; k < le32_to_cpu(inode_count); k++) {
base = inode_table + offset;
if (get_unaligned_le32(&base->inode_number) == inode_number)
return inode_table + offset;
sz = sqfs_inode_size(base, le32_to_cpu(block_size));
if (sz < 0)
return NULL;
offset += sz;
}
printf("Inode not found.\n");
return NULL;
}
int sqfs_read_metablock(unsigned char *file_mapping, int offset,
bool *compressed, u32 *data_size)
{
unsigned char *data;
u16 header;
data = file_mapping + offset;
header = get_unaligned((u16 *)data);
*compressed = SQFS_COMPRESSED_METADATA(header);
*data_size = SQFS_METADATA_SIZE(header);
if (*data_size > SQFS_METADATA_BLOCK_SIZE) {
printf("Invalid metatada block size: %d bytes.\n", *data_size);
return -EINVAL;
}
return 0;
}

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fs/squashfs/sqfs_utils.h Normal file
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@ -0,0 +1,49 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020 Bootlin
*
* Author: Joao Marcos Costa <joaomarcos.costa@bootlin.com>
*/
#ifndef SQFS_UTILS_H
#define SQFS_UTILS_H
#include <linux/bitops.h>
#include <linux/kernel.h>
#include <stdbool.h>
#define SQFS_FRAGMENT_INDEX_OFFSET(A) ((A) % SQFS_MAX_ENTRIES)
#define SQFS_FRAGMENT_INDEX(A) ((A) / SQFS_MAX_ENTRIES)
#define SQFS_BLOCK_SIZE(A) ((A) & GENMASK(23, 0))
#define SQFS_CHECK_FLAG(flag, bit) (((flag) >> (bit)) & 1)
/* Useful for both fragment and data blocks */
#define SQFS_COMPRESSED_BLOCK(A) (!((A) & BIT(24)))
/* SQFS_COMPRESSED_DATA strictly used with super block's 'flags' member */
#define SQFS_COMPRESSED_DATA(A) (!((A) & 0x0002))
#define SQFS_IS_FRAGMENTED(A) ((A) != 0xFFFFFFFF)
/*
* These two macros work as getters for a metada block header, retrieving the
* data size and if it is compressed/uncompressed
*/
#define SQFS_COMPRESSED_METADATA(A) (!((A) & BIT(15)))
#define SQFS_METADATA_SIZE(A) ((A) & GENMASK(14, 0))
struct squashfs_super_block_flags {
/* check: unused
* uncompressed_ids: not supported
*/
bool uncompressed_inodes;
bool uncompressed_data;
bool check;
bool uncompressed_frags;
bool no_frags;
bool always_frags;
bool duplicates;
bool exportable;
bool uncompressed_xattrs;
bool no_xattrs;
bool compressor_options;
bool uncompressed_ids;
};
#endif /* SQFS_UTILS_H */

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@ -15,6 +15,7 @@ struct cmd_tbl;
#define FS_TYPE_SANDBOX 3
#define FS_TYPE_UBIFS 4
#define FS_TYPE_BTRFS 5
#define FS_TYPE_SQUASHFS 6
struct blk_desc;

25
include/squashfs.h Normal file
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@ -0,0 +1,25 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020 Bootlin
*
* Author: Joao Marcos Costa <joaomarcos.costa@bootlin.com>
*
* squashfs.h: SquashFS filesystem implementation.
*/
#ifndef _SQFS_H_
#define _SQFS_H_
struct disk_partition;
int sqfs_opendir(const char *filename, struct fs_dir_stream **dirsp);
int sqfs_readdir(struct fs_dir_stream *dirs, struct fs_dirent **dentp);
int sqfs_probe(struct blk_desc *fs_dev_desc,
struct disk_partition *fs_partition);
int sqfs_read(const char *filename, void *buf, loff_t offset,
loff_t len, loff_t *actread);
int sqfs_size(const char *filename, loff_t *size);
void sqfs_close(void);
void sqfs_closedir(struct fs_dir_stream *dirs);
#endif /* SQFS_H */