From: Christian Taedcke christian.taedcke@weidmueller.com

This reduces code duplications.

Signed-off-by: Christian Taedcke christian.taedcke@weidmueller.com ---

(no changes since v2)

Changes in v2: - Use get_unaligned_le16 instead of custom macro

fs/fat/fat.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/fat/fat.c b/fs/fat/fat.c index 8ff1fd0ec8..a3522340ef 100644 --- a/fs/fat/fat.c +++ b/fs/fat/fat.c @@ -18,6 +18,7 @@ #include <fs.h> #include <log.h> #include <asm/byteorder.h> +#include <asm/unaligned.h> #include <part.h> #include <malloc.h> #include <memalign.h> @@ -571,7 +572,7 @@ static int get_fs_info(fsdata *mydata) mydata->total_sect = bs.total_sect; } else { mydata->fatlength = bs.fat_length; - mydata->total_sect = (bs.sectors[1] << 8) + bs.sectors[0]; + mydata->total_sect = get_unaligned_le16(bs.sectors); if (!mydata->total_sect) mydata->total_sect = bs.total_sect; } @@ -583,7 +584,7 @@ static int get_fs_info(fsdata *mydata)

mydata->rootdir_sect = mydata->fat_sect + mydata->fatlength * bs.fats;

- mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0]; + mydata->sect_size = get_unaligned_le16(bs.sector_size); mydata->clust_size = bs.cluster_size; if (mydata->sect_size != cur_part_info.blksz) { log_err("FAT sector size mismatch (fs=%u, dev=%lu)\n", @@ -607,8 +608,7 @@ static int get_fs_info(fsdata *mydata) (mydata->clust_size * 2); mydata->root_cluster = bs.root_cluster; } else { - mydata->rootdir_size = ((bs.dir_entries[1] * (int)256 + - bs.dir_entries[0]) * + mydata->rootdir_size = (get_unaligned_le16(bs.dir_entries) * sizeof(dir_entry)) / mydata->sect_size; mydata->data_begin = mydata->rootdir_sect +

From: Christian Taedcke christian.taedcke@weidmueller.com

This fixes an issue where the FAT type (FAT12, FAT16) is not correctly detected, e.g. when the BPB field BS_FilSysType contains the valid value "FAT ".

According to the FAT spec the field BS_FilSysType has only informational character and does not determine the FAT type.

The logic of this code is based on the linux kernel implementation from the file fs/fat/inode.c function fat_fill_super().

For details about FAT see http://elm-chan.org/docs/fat_e.html

Signed-off-by: Christian Taedcke christian.taedcke@weidmueller.com ---

(no changes since v2)

Changes in v2: - Use get_unaligned_le16 instead of custom macro - Extract FAT32 logic from determine_fat_bits() into read_bootsectandvi() - Rename determine_fat_bits() to determine_legacy_fat_bits()

fs/fat/fat.c | 48 ++++++++++++++++++++++++++++-------------------- include/fat.h | 6 ------ 2 files changed, 28 insertions(+), 26 deletions(-)

diff --git a/fs/fat/fat.c b/fs/fat/fat.c index a3522340ef..c368c3b076 100644 --- a/fs/fat/fat.c +++ b/fs/fat/fat.c @@ -26,6 +26,9 @@ #include <linux/compiler.h> #include <linux/ctype.h>

+/* maximum number of clusters for FAT12 */ +#define MAX_FAT12 0xFF4 + /* * Convert a string to lowercase. Converts at most 'len' characters, * 'len' may be larger than the length of 'str' if 'str' is NULL @@ -484,6 +487,27 @@ static __u8 mkcksum(struct nameext *nameext) return ret; }

+/* + * Determine if the FAT type is FAT12 or FAT16 + * + * Based on fat_fill_super() from the Linux kernel's fs/fat/inode.c + */ +static int determine_legacy_fat_bits(const boot_sector *bs) +{ + u16 fat_start = bs->reserved; + u32 dir_start = fat_start + bs->fats * bs->fat_length; + u32 rootdir_sectors = get_unaligned_le16(bs->dir_entries) * + sizeof(dir_entry) / + get_unaligned_le16(bs->sector_size); + u32 data_start = dir_start + rootdir_sectors; + u16 sectors = get_unaligned_le16(bs->sectors); + u32 total_sectors = sectors ? sectors : bs->total_sect; + u32 total_clusters = (total_sectors - data_start) / + bs->cluster_size; + + return (total_clusters > MAX_FAT12) ? 16 : 12; +} + /* * Read boot sector and volume info from a FAT filesystem */ @@ -518,7 +542,7 @@ read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize) bs->total_sect = FAT2CPU32(bs->total_sect);

/* FAT32 entries */ - if (bs->fat_length == 0) { + if (!bs->fat_length && bs->fat32_length) { /* Assume FAT32 */ bs->fat32_length = FAT2CPU32(bs->fat32_length); bs->flags = FAT2CPU16(bs->flags); @@ -529,25 +553,10 @@ read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize) *fatsize = 32; } else { vistart = (volume_info *)&(bs->fat32_length); - *fatsize = 0; + *fatsize = determine_legacy_fat_bits(bs); } memcpy(volinfo, vistart, sizeof(volume_info)); - - if (*fatsize == 32) { - if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0) - goto exit; - } else { - if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) { - *fatsize = 12; - goto exit; - } - if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) { - *fatsize = 16; - goto exit; - } - } - - debug("Error: broken fs_type sign\n"); + goto exit; fail: ret = -1; exit: @@ -1157,9 +1166,8 @@ int file_fat_detectfs(void)

memcpy(vol_label, volinfo.volume_label, 11); vol_label[11] = '\0'; - volinfo.fs_type[5] = '\0';

- printf("Filesystem: %s "%s"\n", volinfo.fs_type, vol_label); + printf("Filesystem: FAT%d "%s"\n", fatsize, vol_label);

return 0; } diff --git a/include/fat.h b/include/fat.h index a9756fb4cd..3dce99a23c 100644 --- a/include/fat.h +++ b/include/fat.h @@ -34,12 +34,6 @@ struct disk_partition; /* Maximum number of entry for long file name according to spec */ #define MAX_LFN_SLOT 20

-/* Filesystem identifiers */ -#define FAT12_SIGN "FAT12 " -#define FAT16_SIGN "FAT16 " -#define FAT32_SIGN "FAT32 " -#define SIGNLEN 8 - /* File attributes */ #define ATTR_RO 1 #define ATTR_HIDDEN 2

From: Christian Taedcke christian.taedcke@weidmueller.com

The performed checks are similar to the checks performed by the Linux kernel in the function fat_read_bpb() in the file fs/fat/inode.c.

Signed-off-by: Christian Taedcke christian.taedcke@weidmueller.com ---

(no changes since v2)

Changes in v2: - Add validity checks for boot sector

fs/fat/fat.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+)

diff --git a/fs/fat/fat.c b/fs/fat/fat.c index 77f225ccd8..14e53cf2d5 100644 --- a/fs/fat/fat.c +++ b/fs/fat/fat.c @@ -25,6 +25,7 @@ #include <asm/cache.h> #include <linux/compiler.h> #include <linux/ctype.h> +#include <linux/log2.h>

/* maximum number of clusters for FAT12 */ #define MAX_FAT12 0xFF4 @@ -508,6 +509,52 @@ static int determine_legacy_fat_bits(const boot_sector *bs) return (total_clusters > MAX_FAT12) ? 16 : 12; }

+/* + * Determines if the boot sector's media field is valid + * + * Based on fat_valid_media() from Linux kernel's include/linux/msdos_fs.h + */ +static int fat_valid_media(u8 media) +{ + return media >= 0xf8 || media == 0xf0; +} + +/* + * Determines if the given boot sector is valid + * + * Based on fat_read_bpb() from the Linux kernel's fs/fat/inode.c + */ +static int is_bootsector_valid(const boot_sector *bs) +{ + u16 sector_size = get_unaligned_le16(bs->sector_size); + u16 dir_per_block = sector_size / sizeof(dir_entry); + + if (!bs->reserved) + return 0; + + if (!bs->fats) + return 0; + + if (!fat_valid_media(bs->media)) + return 0; + + if (!is_power_of_2(sector_size) || + sector_size < 512 || + sector_size > 4096) + return 0; + + if (!is_power_of_2(bs->cluster_size)) + return 0; + + if (!bs->fat_length && !bs->fat32_length) + return 0; + + if (get_unaligned_le16(bs->dir_entries) & (dir_per_block - 1)) + return 0; + + return 1; +} + /* * Read boot sector and volume info from a FAT filesystem */ @@ -542,6 +589,12 @@ read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize) bs->heads = FAT2CPU16(bs->heads); bs->total_sect = FAT2CPU32(bs->total_sect);

+ if (!is_bootsector_valid(bs)) { + debug("Error: bootsector is invalid\n"); + ret = -1; + goto out_free; + } + /* FAT32 entries */ if (!bs->fat_length && bs->fat32_length) { /* Assume FAT32 */

From: Christian Taedcke christian.taedcke@weidmueller.com

The tests fs_ext, fs_mkdir and fs_unlink support fat12 without modifications. The fs_basic test uses a partition that is too large for fat12, so it is omitted here.

Signed-off-by: Christian Taedcke christian.taedcke@weidmueller.com ---

Changes in v3: - Enable some fs tests for FAT12

test/py/tests/test_fs/conftest.py | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/test/py/tests/test_fs/conftest.py b/test/py/tests/test_fs/conftest.py index 0d87d180c7..fa637a22a0 100644 --- a/test/py/tests/test_fs/conftest.py +++ b/test/py/tests/test_fs/conftest.py @@ -12,9 +12,9 @@ import u_boot_utils as util from tests import fs_helper

supported_fs_basic = ['fat16', 'fat32', 'ext4'] -supported_fs_ext = ['fat16', 'fat32'] -supported_fs_mkdir = ['fat16', 'fat32'] -supported_fs_unlink = ['fat16', 'fat32'] +supported_fs_ext = ['fat12', 'fat16', 'fat32'] +supported_fs_mkdir = ['fat12', 'fat16', 'fat32'] +supported_fs_unlink = ['fat12', 'fat16', 'fat32'] supported_fs_symlink = ['ext4']

#

From: Christian Taedcke christian.taedcke@weidmueller.com

Ensure that a large FAT12 filesystem and a small FAT16 filesystem are detected correctly.

Signed-off-by: Christian Taedcke christian.taedcke@weidmueller.com ---

Changes in v3: - Add test to detect fat fs type

test/py/tests/test_fs/conftest.py | 47 ++++++++++++++++++++++++++++ test/py/tests/test_fs/test_fs_fat.py | 25 +++++++++++++++ 2 files changed, 72 insertions(+) create mode 100644 test/py/tests/test_fs/test_fs_fat.py

diff --git a/test/py/tests/test_fs/conftest.py b/test/py/tests/test_fs/conftest.py index fa637a22a0..fdd138d6ee 100644 --- a/test/py/tests/test_fs/conftest.py +++ b/test/py/tests/test_fs/conftest.py @@ -13,6 +13,7 @@ from tests import fs_helper

supported_fs_basic = ['fat16', 'fat32', 'ext4'] supported_fs_ext = ['fat12', 'fat16', 'fat32'] +supported_fs_fat = ['fat12', 'fat16'] supported_fs_mkdir = ['fat12', 'fat16', 'fat32'] supported_fs_unlink = ['fat12', 'fat16', 'fat32'] supported_fs_symlink = ['ext4'] @@ -49,6 +50,7 @@ def pytest_configure(config): """ global supported_fs_basic global supported_fs_ext + global supported_fs_fat global supported_fs_mkdir global supported_fs_unlink global supported_fs_symlink @@ -61,6 +63,7 @@ def pytest_configure(config): print('*** FS TYPE modified: %s' % supported_fs) supported_fs_basic = intersect(supported_fs, supported_fs_basic) supported_fs_ext = intersect(supported_fs, supported_fs_ext) + supported_fs_fat = intersect(supported_fs, supported_fs_fat) supported_fs_mkdir = intersect(supported_fs, supported_fs_mkdir) supported_fs_unlink = intersect(supported_fs, supported_fs_unlink) supported_fs_symlink = intersect(supported_fs, supported_fs_symlink) @@ -83,6 +86,9 @@ def pytest_generate_tests(metafunc): if 'fs_obj_ext' in metafunc.fixturenames: metafunc.parametrize('fs_obj_ext', supported_fs_ext, indirect=True, scope='module') + if 'fs_obj_fat' in metafunc.fixturenames: + metafunc.parametrize('fs_obj_fat', supported_fs_fat, + indirect=True, scope='module') if 'fs_obj_mkdir' in metafunc.fixturenames: metafunc.parametrize('fs_obj_mkdir', supported_fs_mkdir, indirect=True, scope='module') @@ -624,3 +630,44 @@ def fs_obj_symlink(request, u_boot_config): finally: call('rmdir %s' % mount_dir, shell=True) call('rm -f %s' % fs_img, shell=True) + +# +# Fixture for fat test +# +@pytest.fixture() +def fs_obj_fat(request, u_boot_config): + """Set up a file system to be used in fat test. + + Args: + request: Pytest request object. + u_boot_config: U-Boot configuration. + + Return: + A fixture for fat test, i.e. a duplet of file system type and + volume file name. + """ + + # the maximum size of a FAT12 filesystem resulting in 4084 clusters + MAX_FAT12_SIZE = 261695 * 1024 + + # the minimum size of a FAT16 filesystem that can be created with + # mkfs.vfat resulting in 4087 clusters + MIN_FAT16_SIZE = 8208 * 1024 + + fs_type = request.param + fs_img = '' + + fs_ubtype = fstype_to_ubname(fs_type) + check_ubconfig(u_boot_config, fs_ubtype) + + fs_size = MAX_FAT12_SIZE if fs_type == 'fat12' else MIN_FAT16_SIZE + + try: + # the volume size depends on the filesystem + fs_img = fs_helper.mk_fs(u_boot_config, fs_type, fs_size, f'{fs_size}', 1024) + except: + pytest.skip('Setup failed for filesystem: ' + fs_type) + return + else: + yield [fs_ubtype, fs_img] + call('rm -f %s' % fs_img, shell=True) diff --git a/test/py/tests/test_fs/test_fs_fat.py b/test/py/tests/test_fs/test_fs_fat.py new file mode 100644 index 0000000000..4009d0b63a --- /dev/null +++ b/test/py/tests/test_fs/test_fs_fat.py @@ -0,0 +1,25 @@ +# SPDX-License-Identifier: GPL-2.0+ +# Copyright (c) 2023 Weidmüller Interface GmbH & Co. KG +# Author: Christian Taedcke christian.taedcke@weidmueller.com +# +# U-Boot File System: FAT Test + +""" +This test verifies fat specific file system behaviour. +""" + +import pytest +import re + +@pytest.mark.boardspec('sandbox') +@pytest.mark.slow +class TestFsFat(object): + def test_fs_fat1(self, u_boot_console, fs_obj_fat): + """Test that `fstypes` prints a result which includes `sandbox`.""" + fs_type,fs_img = fs_obj_fat + with u_boot_console.log.section('Test Case 1 - fatinfo'): + # Test Case 1 - ls + output = u_boot_console.run_command_list([ + 'host bind 0 %s' % fs_img, + 'fatinfo host 0:0']) + assert(re.search('Filesystem: %s' % fs_type.upper(), ''.join(output)))