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增加大文件支持需求 #38

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155 changes: 121 additions & 34 deletions dfs_lfs.c
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Original file line number Diff line number Diff line change
Expand Up @@ -15,13 +15,30 @@
#include <stdio.h>
#include <string.h>

#if defined(RT_VERSION_CHECK) && (RTTHREAD_VERSION >= RT_VERSION_CHECK(5, 0, 2))
#if defined(DFS_OFF_MAX)
#define DFS_LFS_DFS_OFF_TYPE dfs_off_t
#define DFS_LFS_FILE_OFF_TYPE dfs_off_t
#define DFS_LFS_STAT_TYPE struct dfs_stat
#define DFS_LFS_STAT_MTIME(st) ((st)->mtime)
#elif defined(RT_USING_DFS_V2)
#define DFS_LFS_DFS_OFF_TYPE off_t
#define DFS_LFS_FILE_OFF_TYPE off_t
#define DFS_LFS_STAT_TYPE struct stat
#define DFS_LFS_STAT_MTIME(st) ((st)->st_mtime)
#else
#define DFS_LFS_DFS_OFF_TYPE off_t
#define DFS_LFS_FILE_OFF_TYPE rt_off_t
#define DFS_LFS_STAT_TYPE struct stat
#define DFS_LFS_STAT_MTIME(st) ((st)->st_mtime)
#endif

#if defined(DFS_OFF_MAX) || (defined(RT_VERSION_CHECK) && (RTTHREAD_VERSION >= RT_VERSION_CHECK(5, 0, 2)))
#define DFS_LFS_RW_RETURN_TYPE ssize_t
#define DFS_LFS_LSK_RETURN_TYPE off_t
#define DFS_LFS_LSK_RETURN_TYPE DFS_LFS_DFS_OFF_TYPE
#else
#define DFS_LFS_RW_RETURN_TYPE int
#define DFS_LFS_LSK_RETURN_TYPE int
#endif /* defined(RT_VERSION_CHECK) && (RTTHREAD_VERSION >= RT_VERSION_CHECK(5, 0, 2)) */
#endif /* defined(DFS_OFF_MAX) || (defined(RT_VERSION_CHECK) && (RTTHREAD_VERSION >= RT_VERSION_CHECK(5, 0, 2))) */

#if defined(RT_USING_DFS_V2) || (defined(RT_VERSION_CHECK) && (RTTHREAD_VERSION >= RT_VERSION_CHECK(5, 0, 0)))
#define DFS_LFS_MKFS_PARAMS rt_device_t dev_id, const char *fs_name
Expand Down Expand Up @@ -59,12 +76,12 @@
#define DFS_LFS_FILE_REF_COUNT(file) ((file)->vnode->ref_count)
#define DFS_LFS_FILE_IS_VALID(file) ((file)->vnode != RT_NULL)
#define DFS_LFS_FILE_FS(file) ((file)->dentry->mnt)
#define DFS_LFS_READ_PARAMS DFS_LFS_FILE_STRUCT* file, void* buf, size_t len, off_t* pos
#define DFS_LFS_WRITE_PARAMS DFS_LFS_FILE_STRUCT* file, const void* buf, size_t len, off_t* pos
#define DFS_LFS_LSEEK_PARAMS DFS_LFS_FILE_STRUCT* file, off_t offset, int whence
#define DFS_LFS_READ_PARAMS DFS_LFS_FILE_STRUCT* file, void* buf, size_t len, DFS_LFS_DFS_OFF_TYPE* pos
#define DFS_LFS_WRITE_PARAMS DFS_LFS_FILE_STRUCT* file, const void* buf, size_t len, DFS_LFS_DFS_OFF_TYPE* pos
#define DFS_LFS_LSEEK_PARAMS DFS_LFS_FILE_STRUCT* file, DFS_LFS_DFS_OFF_TYPE offset, int whence
#define DFS_LFS_IO_POS_PARAM pos
#define DFS_LFS_LSEEK_WHENCE whence
#define DFS_LFS_STORE_FILE_POS(file, pos, lfs_pos) (*(pos) = (off_t)(lfs_pos))
#define DFS_LFS_STORE_FILE_POS(file, pos, lfs_pos) (*(pos) = (DFS_LFS_DFS_OFF_TYPE)(lfs_pos))
#define DFS_LFS_REGISTER() dfs_register(&_dfs_lfs_type)
#elif defined(RT_VERSION_CHECK) && (RTTHREAD_VERSION >= RT_VERSION_CHECK(5, 0, 2))
/**
Expand All @@ -85,10 +102,10 @@
#define DFS_LFS_FILE_FS(file) ((file)->vnode->fs)
#define DFS_LFS_READ_PARAMS DFS_LFS_FILE_STRUCT* file, void* buf, size_t len
#define DFS_LFS_WRITE_PARAMS DFS_LFS_FILE_STRUCT* file, const void* buf, size_t len
#define DFS_LFS_LSEEK_PARAMS DFS_LFS_FILE_STRUCT* file, rt_off_t offset
#define DFS_LFS_LSEEK_PARAMS DFS_LFS_FILE_STRUCT* file, DFS_LFS_FILE_OFF_TYPE offset
#define DFS_LFS_IO_POS_PARAM RT_NULL
#define DFS_LFS_LSEEK_WHENCE SEEK_SET
#define DFS_LFS_STORE_FILE_POS(file, pos, lfs_pos) (DFS_LFS_FILE_POS(file) = (rt_off_t)(lfs_pos))
#define DFS_LFS_STORE_FILE_POS(file, pos, lfs_pos) (DFS_LFS_FILE_POS(file) = (DFS_LFS_FILE_OFF_TYPE)(lfs_pos))
#define DFS_LFS_FS_FLAGS DFS_FS_FLAG_DEFAULT
#define DFS_LFS_REGISTER() dfs_register(&_dfs_lfs_ops)
#elif defined(RT_USING_DFS_V1)
Expand All @@ -114,10 +131,10 @@
#define DFS_LFS_FILE_FS(file) ((file)->vnode->fs)
#define DFS_LFS_READ_PARAMS DFS_LFS_FILE_STRUCT* file, void* buf, size_t len
#define DFS_LFS_WRITE_PARAMS DFS_LFS_FILE_STRUCT* file, const void* buf, size_t len
#define DFS_LFS_LSEEK_PARAMS DFS_LFS_FILE_STRUCT* file, rt_off_t offset
#define DFS_LFS_LSEEK_PARAMS DFS_LFS_FILE_STRUCT* file, DFS_LFS_FILE_OFF_TYPE offset
#define DFS_LFS_IO_POS_PARAM RT_NULL
#define DFS_LFS_LSEEK_WHENCE SEEK_SET
#define DFS_LFS_STORE_FILE_POS(file, pos, lfs_pos) (DFS_LFS_FILE_POS(file) = (rt_off_t)(lfs_pos))
#define DFS_LFS_STORE_FILE_POS(file, pos, lfs_pos) (DFS_LFS_FILE_POS(file) = (DFS_LFS_FILE_OFF_TYPE)(lfs_pos))
#define DFS_LFS_FS_FLAGS DFS_FS_FLAG_DEFAULT
#define DFS_LFS_REGISTER() dfs_register(&_dfs_lfs_ops)
#elif defined(RT_VERSION_CHECK) && (RTTHREAD_VERSION >= RT_VERSION_CHECK(5, 0, 0))
Expand All @@ -142,10 +159,10 @@
#define DFS_LFS_FILE_FS(file) ((file)->vnode->fs)
#define DFS_LFS_READ_PARAMS DFS_LFS_FILE_STRUCT* file, void* buf, size_t len
#define DFS_LFS_WRITE_PARAMS DFS_LFS_FILE_STRUCT* file, const void* buf, size_t len
#define DFS_LFS_LSEEK_PARAMS DFS_LFS_FILE_STRUCT* file, rt_off_t offset
#define DFS_LFS_LSEEK_PARAMS DFS_LFS_FILE_STRUCT* file, DFS_LFS_FILE_OFF_TYPE offset
#define DFS_LFS_IO_POS_PARAM RT_NULL
#define DFS_LFS_LSEEK_WHENCE SEEK_SET
#define DFS_LFS_STORE_FILE_POS(file, pos, lfs_pos) (DFS_LFS_FILE_POS(file) = (rt_off_t)(lfs_pos))
#define DFS_LFS_STORE_FILE_POS(file, pos, lfs_pos) (DFS_LFS_FILE_POS(file) = (DFS_LFS_FILE_OFF_TYPE)(lfs_pos))
#define DFS_LFS_FS_FLAGS DFS_FS_FLAG_DEFAULT
#define DFS_LFS_REGISTER() dfs_register(&_dfs_lfs_ops)
#else
Expand All @@ -170,10 +187,10 @@
#define DFS_LFS_FILE_FS(file) ((file)->fs)
#define DFS_LFS_READ_PARAMS DFS_LFS_FILE_STRUCT* file, void* buf, size_t len
#define DFS_LFS_WRITE_PARAMS DFS_LFS_FILE_STRUCT* file, const void* buf, size_t len
#define DFS_LFS_LSEEK_PARAMS DFS_LFS_FILE_STRUCT* file, rt_off_t offset
#define DFS_LFS_LSEEK_PARAMS DFS_LFS_FILE_STRUCT* file, DFS_LFS_FILE_OFF_TYPE offset
#define DFS_LFS_IO_POS_PARAM RT_NULL
#define DFS_LFS_LSEEK_WHENCE SEEK_SET
#define DFS_LFS_STORE_FILE_POS(file, pos, lfs_pos) (DFS_LFS_FILE_POS(file) = (rt_off_t)(lfs_pos))
#define DFS_LFS_STORE_FILE_POS(file, pos, lfs_pos) (DFS_LFS_FILE_POS(file) = (DFS_LFS_FILE_OFF_TYPE)(lfs_pos))
#define DFS_LFS_FS_FLAGS DFS_FS_FLAG_DEFAULT
#define DFS_LFS_REGISTER() dfs_register(&_dfs_lfs_ops)
#endif /* defined(RT_USING_DFS_V2) */
Expand Down Expand Up @@ -406,6 +423,10 @@ static int _lfs_result_to_dfs(int result)
status = -ENOMEM;
break; // No more memory available

case LFS_ERR_FBIG:
status = -EFBIG;
break; // File too large

case LFS_ERR_CORRUPT:
status = -52;
break; // Corrupted
Expand All @@ -418,10 +439,41 @@ static int _lfs_result_to_dfs(int result)
return status;
}

static int _dfs_lfs_check_lfs_range(int64_t offset)
{
if (offset < 0 || offset > (DFS_LFS_DFS_OFF_TYPE)LFS_FILE_MAX)
{
return -EINVAL;
}

return RT_EOK;
}

#if defined(RT_USING_DFS_V2)
static int _dfs_lfs_add_file_off(DFS_LFS_FILE_OFF_TYPE base,
DFS_LFS_FILE_OFF_TYPE delta,
DFS_LFS_FILE_OFF_TYPE* result)
{
if (base < 0)
{
return -EINVAL;
}

if ((delta > 0 && base > (DFS_LFS_FILE_OFF_TYPE)LFS_FILE_MAX - delta)
|| (delta < 0 && delta < -base))
{
return -EINVAL;
}

*result = base + delta;
return RT_EOK;
}
#endif /* defined(RT_USING_DFS_V2) */

/* DFS v2 passes read/write offsets explicitly. Keep DFS v1 behavior unchanged. */
static int _dfs_lfs_sync_file_pos(DFS_LFS_FILE_STRUCT* file,
dfs_lfs_fd_t* dfs_lfs_fd,
off_t* pos)
DFS_LFS_DFS_OFF_TYPE* pos)
{
#if defined(RT_USING_DFS_V2)
lfs_soff_t current;
Expand All @@ -432,7 +484,13 @@ static int _dfs_lfs_sync_file_pos(DFS_LFS_FILE_STRUCT* file,
RT_ASSERT(dfs_lfs_fd != RT_NULL);
RT_ASSERT(pos != RT_NULL);

result = _dfs_lfs_check_lfs_range((int64_t)*pos);
if (result < 0)
{
return result;
}
target = (lfs_soff_t)*pos;

current = lfs_file_tell(dfs_lfs_fd->lfs, &dfs_lfs_fd->u.file);
if (current < 0)
{
Expand Down Expand Up @@ -696,9 +754,9 @@ static int _dfs_lfs_unlink(DFS_LFS_MNT_TYPE* dfs, const char* path)
}
#endif

static void _dfs_lfs_tostat(struct stat* st, struct lfs_info* info, time_t mtime)
static void _dfs_lfs_tostat(DFS_LFS_STAT_TYPE* st, struct lfs_info* info, time_t mtime)
{
memset(st, 0, sizeof(struct stat));
memset(st, 0, sizeof(DFS_LFS_STAT_TYPE));

/* convert to dfs stat structure */
st->st_dev = 0;
Expand All @@ -716,10 +774,10 @@ static void _dfs_lfs_tostat(struct stat* st, struct lfs_info* info, time_t mtime
break;
}

st->st_mtime = mtime;
DFS_LFS_STAT_MTIME(st) = mtime;
}

static int _dfs_lfs_stat(DFS_LFS_MNT_TYPE* dfs, const char* path, struct stat* st)
static int _dfs_lfs_stat(DFS_LFS_MNT_TYPE* dfs, const char* path, DFS_LFS_STAT_TYPE* st)
{
dfs_lfs_t* dfs_lfs;
int result;
Expand Down Expand Up @@ -938,8 +996,9 @@ static int _dfs_lfs_ioctl(DFS_LFS_FILE_STRUCT* file, int cmd, void* args)
return -EROFS;
#else
dfs_lfs_fd_t *dfs_lfs_fd;
off_t length;
DFS_LFS_DFS_OFF_TYPE length;
int result;
lfs_off_t lfs_size;
lfs_soff_t pos;

RT_ASSERT(file != RT_NULL);
Expand All @@ -960,15 +1019,17 @@ static int _dfs_lfs_ioctl(DFS_LFS_FILE_STRUCT* file, int cmd, void* args)
return -EBADF;
}

length = *(off_t *)args;
if (length < 0)
length = *(DFS_LFS_DFS_OFF_TYPE *)args;
result = _dfs_lfs_check_lfs_range((int64_t)length);
if (result < 0)
{
return -EINVAL;
return result;
}
lfs_size = (lfs_off_t)length;

dfs_lfs_fd = (dfs_lfs_fd_t *)file->data;

result = lfs_file_truncate(dfs_lfs_fd->lfs, &dfs_lfs_fd->u.file, (lfs_off_t)length);
result = lfs_file_truncate(dfs_lfs_fd->lfs, &dfs_lfs_fd->u.file, lfs_size);
if (result < 0)
{
return _lfs_result_to_dfs(result);
Expand All @@ -979,14 +1040,14 @@ static int _dfs_lfs_ioctl(DFS_LFS_FILE_STRUCT* file, int cmd, void* args)
{
return _lfs_result_to_dfs((int)pos);
}
DFS_LFS_FILE_POS(file) = (rt_off_t)pos;
DFS_LFS_FILE_POS(file) = (DFS_LFS_FILE_OFF_TYPE)pos;

pos = lfs_file_size(dfs_lfs_fd->lfs, &dfs_lfs_fd->u.file);
if (pos < 0)
{
return _lfs_result_to_dfs((int)pos);
}
DFS_LFS_FILE_SIZE(file) = (rt_off_t)pos;
DFS_LFS_FILE_SIZE(file) = (DFS_LFS_FILE_OFF_TYPE)pos;

return RT_EOK;
#endif
Expand All @@ -1000,7 +1061,7 @@ static int _dfs_lfs_ioctl(DFS_LFS_FILE_STRUCT* file, int cmd, void* args)
}

#if defined(RT_USING_DFS_V2) && !defined(LFS_READONLY)
static int _dfs_lfs_truncate(DFS_LFS_FILE_STRUCT* file, off_t length)
static int _dfs_lfs_truncate(DFS_LFS_FILE_STRUCT* file, DFS_LFS_DFS_OFF_TYPE length)
{
return _dfs_lfs_ioctl(file, RT_FIOFTRUNCATE, &length);
}
Expand Down Expand Up @@ -1100,6 +1161,8 @@ static int _dfs_lfs_flush(DFS_LFS_FILE_STRUCT* file)
static DFS_LFS_LSK_RETURN_TYPE _dfs_lfs_lseek(DFS_LFS_LSEEK_PARAMS)
{
dfs_lfs_fd_t* dfs_lfs_fd;
lfs_soff_t lfs_offset;
int result;

RT_ASSERT(file != RT_NULL);
RT_ASSERT(file->data != RT_NULL);
Expand All @@ -1112,10 +1175,18 @@ static DFS_LFS_LSK_RETURN_TYPE _dfs_lfs_lseek(DFS_LFS_LSEEK_PARAMS)
case SEEK_SET:
break;
case SEEK_CUR:
offset += DFS_LFS_FILE_POS(file);
result = _dfs_lfs_add_file_off(DFS_LFS_FILE_POS(file), offset, &offset);
if (result < 0)
{
return result;
}
break;
case SEEK_END:
offset += DFS_LFS_FILE_SIZE(file);
result = _dfs_lfs_add_file_off(DFS_LFS_FILE_SIZE(file), offset, &offset);
if (result < 0)
{
return result;
}
break;
default:
return -EINVAL;
Expand All @@ -1124,7 +1195,16 @@ static DFS_LFS_LSK_RETURN_TYPE _dfs_lfs_lseek(DFS_LFS_LSEEK_PARAMS)

if (DFS_LFS_FILE_TYPE(file) == FT_REGULAR)
{
lfs_soff_t soff = lfs_file_seek(dfs_lfs_fd->lfs, &dfs_lfs_fd->u.file, offset, LFS_SEEK_SET);
lfs_soff_t soff;

result = _dfs_lfs_check_lfs_range((int64_t)offset);
if (result < 0)
{
return result;
}
lfs_offset = (lfs_soff_t)offset;

soff = lfs_file_seek(dfs_lfs_fd->lfs, &dfs_lfs_fd->u.file, lfs_offset, LFS_SEEK_SET);
if (soff < 0)
{
return _lfs_result_to_dfs((int)soff);
Expand All @@ -1137,6 +1217,7 @@ static DFS_LFS_LSK_RETURN_TYPE _dfs_lfs_lseek(DFS_LFS_LSEEK_PARAMS)
lfs_off_t off;
lfs_soff_t soff;
DFS_LFS_LSK_RETURN_TYPE dirent_size;
DFS_LFS_FILE_OFF_TYPE entry_index;

dirent_size = (DFS_LFS_LSK_RETURN_TYPE)sizeof(struct dirent);
if ((offset < 0) || ((offset % dirent_size) != 0))
Expand All @@ -1145,7 +1226,13 @@ static DFS_LFS_LSK_RETURN_TYPE _dfs_lfs_lseek(DFS_LFS_LSEEK_PARAMS)
}

/* skip . and .. */
off = (lfs_off_t)(offset / dirent_size) + 2;
entry_index = (DFS_LFS_FILE_OFF_TYPE)(offset / dirent_size);
if (entry_index > (DFS_LFS_FILE_OFF_TYPE)((lfs_off_t)-1 - 2))
{
return -EINVAL;
}

off = (lfs_off_t)entry_index + 2;
Comment on lines +1229 to +1235

@coderabbitai coderabbitai Bot Jun 23, 2026

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🎯 Functional Correctness | 🟠 Major

🧩 Analysis chain

🏁 Script executed:

#!/bin/bash
# Locate rt_off_t / off_t definitions to confirm signed 32-bit configurations exist.
rg -nP '\b(typedef|`#define`)\b.*\b(rt_off_t|off_t)\b'
fd -t f -e h | rg -l 'rt_off_t' | head

Repository: RT-Thread-packages/littlefs

Length of output: 165

🏁 Script executed:

# First, let's locate the dfs_lfs.c file and verify the code snippet
fd -t f -e c | rg 'dfs_lfs' | head -20

Repository: RT-Thread-packages/littlefs

Length of output: 175

🏁 Script executed:

# Search more broadly for type definitions and includes
rg -n 'DFS_LFS_FILE_OFF_TYPE|lfs_off_t' -t c -t h | head -30

Repository: RT-Thread-packages/littlefs

Length of output: 165

🏁 Script executed:

# Look for rt_off_t in header files with broader search
rg 'rt_off_t|off_t' -t h | head -40

Repository: RT-Thread-packages/littlefs

Length of output: 165

🏁 Script executed:

# Find and read the dfs_lfs.c file
fd -t f 'dfs_lfs\.c'

Repository: RT-Thread-packages/littlefs

Length of output: 175

🏁 Script executed:

# Once we have the file, let's look for it and read the relevant lines
git ls-files | grep -E '(dfs_lfs|\.c$)' | head -20

Repository: RT-Thread-packages/littlefs

Length of output: 455

🏁 Script executed:

# Look for any file containing these types
rg 'DFS_LFS_FILE_OFF_TYPE' --type c --type h -l

Repository: RT-Thread-packages/littlefs

Length of output: 165

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# Read the dfs_lfs.c file to see the code context
wc -l dfs_lfs.c

Repository: RT-Thread-packages/littlefs

Length of output: 180

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# Read around lines 1229-1235
sed -n '1220,1245p' dfs_lfs.c

Repository: RT-Thread-packages/littlefs

Length of output: 1074

🏁 Script executed:

# Look for type definitions and includes at the beginning of dfs_lfs.c
head -100 dfs_lfs.c | grep -E 'typedef|include|define.*off'

Repository: RT-Thread-packages/littlefs

Length of output: 744

🏁 Script executed:

# Find lfs_off_t definition
rg 'typedef.*lfs_off_t|lfs_off_t.*=' -A 2 dfs_lfs.c lfs.h

Repository: RT-Thread-packages/littlefs

Length of output: 242

🏁 Script executed:

# Look for off_t and rt_off_t definitions
rg 'typedef.*off_t|typedef.*rt_off_t' -t h

Repository: RT-Thread-packages/littlefs

Length of output: 165

🏁 Script executed:

# Get more context around the DFS_LFS_FILE_OFF_TYPE definitions to understand the conditionals
sed -n '1,50p' dfs_lfs.c

Repository: RT-Thread-packages/littlefs

Length of output: 1903

🏁 Script executed:

# Search for conditional compilation around the typedef block
grep -n -B 10 -A 2 'DFS_LFS_FILE_OFF_TYPE' dfs_lfs.c | head -60

Repository: RT-Thread-packages/littlefs

Length of output: 3840

🏁 Script executed:

# Search in included headers for rt_off_t and off_t definitions
# These are likely in RT-Thread system headers, but let's check what we have available
rg 'typedef.*rt_off_t|typedef.*off_t' -i -t h --type-add 'headers:include'

Repository: RT-Thread-packages/littlefs

Length of output: 165

🏁 Script executed:

# Look at what rtthread.h includes
grep -r 'typedef.*off_t' --include='*.h' | head -20

Repository: RT-Thread-packages/littlefs

Length of output: 234

🏁 Script executed:

# Check if there are any documentation or comments about type sizes
grep -r 'int32_t.*off_t\|signed.*off_t\|32.*bit' --include='*.h' --include='*.c' | grep -i off | head -20

Repository: RT-Thread-packages/littlefs

Length of output: 234

🏁 Script executed:

# Let's verify the mathematical logic: compute what (uint32_t)-1 - 2 becomes when cast to int32_t
python3 - <<'PY'
# lfs_off_t is uint32_t (unsigned 32-bit)
lfs_off_t_value = (0xFFFFFFFF - 2) & 0xFFFFFFFF  # (uint32_t)-1 - 2
print(f"(lfs_off_t)-1 - 2 = 0x{lfs_off_t_value:08X} = {lfs_off_t_value}")

# When cast to int32_t (signed 32-bit)
import ctypes
signed_value = ctypes.c_int32(lfs_off_t_value).value
print(f"When cast to int32_t: {signed_value}")

# Test the comparison
entry_index = 0
print(f"\nComparison: entry_index ({entry_index}) > cast_value ({signed_value}) = {entry_index > signed_value}")
entry_index = 1000
print(f"Comparison: entry_index ({entry_index}) > cast_value ({signed_value}) = {entry_index > signed_value}")
PY

Repository: RT-Thread-packages/littlefs

Length of output: 344

🏁 Script executed:

# Search for any context about rt_off_t in comments or documentation
rg 'rt_off_t' -B 3 -A 3 --include='*.c' --include='*.h' --include='*.md'

Repository: RT-Thread-packages/littlefs

Length of output: 607

🏁 Script executed:

# Verify the proposed fix logic
python3 - <<'PY'
# Proposed fix: if ((uint64_t)entry_index > (uint64_t)((lfs_off_t)-1) - 2)

# First, compute the bound in unsigned 64-bit
lfs_off_t_max_val = 0xFFFFFFFF  # (lfs_off_t)-1, which is uint32_t max
bound = lfs_off_t_max_val - 2  # = 0xFFFFFFFD = 4294967293
print(f"Bound in uint64_t: {bound} (0x{bound:016X})")

# Test with various entry_index values
test_values = [0, 1, 2, 100, 4294967291, 4294967293, 4294967294, 4294967295]
print("\nProposed fix comparison: (uint64_t)entry_index > bound")
for val in test_values:
    result = val > bound
    print(f"  entry_index={val}: {val} > {bound} = {result}")

# Also test with original broken logic for comparison
print("\nBroken logic: entry_index > (int32_t)((uint32_t)-1 - 2)")
cast_val = -3
for val in test_values:
    result = val > cast_val
    print(f"  entry_index={val}: {val} > {cast_val} = {result}")
PY

Repository: RT-Thread-packages/littlefs

Length of output: 1047

🏁 Script executed:

# Look for any existing bug reports or comments about this in the code
grep -r 'bound\|overflow\|seek.*off' --include='*.c' --include='*.h' dfs_lfs.c | grep -i 'entry\|directory' | head -10

Repository: RT-Thread-packages/littlefs

Length of output: 165

Directory-seek bound check always rejects valid offsets on signed 32-bit off types.

When DFS_LFS_FILE_OFF_TYPE is rt_off_t (a signed 32-bit type used in legacy DFS v1), the expression (DFS_LFS_FILE_OFF_TYPE)((lfs_off_t)-1 - 2) casts 0xFFFFFFFD from unsigned 32-bit to signed 32-bit, resulting in -3. Since entry_index is non-negative, the comparison entry_index > -3 is always true, causing the function to return -EINVAL for every directory seek operation.

Apply the proposed fix to compare in unsigned 64-bit domain instead:

Fix 
     /* skip . and .. */
     entry_index = (DFS_LFS_FILE_OFF_TYPE)(offset / dirent_size);
-    if (entry_index > (DFS_LFS_FILE_OFF_TYPE)((lfs_off_t)-1 - 2))
+    if ((uint64_t)entry_index > (uint64_t)((lfs_off_t)-1) - 2)
     {
         return -EINVAL;
     }
🤖 Prompt for AI Agents 
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@dfs_lfs.c` around lines 1229 - 1235, The bound check comparison for
entry_index around line 1230 is incorrectly casting an unsigned 64-bit value to
a signed 32-bit type, resulting in -3 instead of the intended upper bound. This
causes the condition to always evaluate to true for valid offsets. Fix this by
casting entry_index to lfs_off_t (unsigned 64-bit) before comparing it to
(lfs_off_t)((lfs_off_t)-1 - 2), ensuring the entire comparison happens in the
unsigned 64-bit domain where the bound check works correctly regardless of
whether DFS_LFS_FILE_OFF_TYPE is signed or unsigned.

soff = lfs_dir_seek(dfs_lfs_fd->lfs, &dfs_lfs_fd->u.dir, off);
if (soff < 0)
{
Expand Down Expand Up @@ -1272,7 +1359,7 @@ static int _dfs_lfs_dentry_rename(struct dfs_dentry* old_dentry, struct dfs_dent
}
#endif /* !defined(LFS_READONLY) */

static int _dfs_lfs_dentry_stat(struct dfs_dentry* dentry, struct stat* st)
static int _dfs_lfs_dentry_stat(struct dfs_dentry* dentry, DFS_LFS_STAT_TYPE* st)
{
RT_ASSERT(dentry != RT_NULL);
RT_ASSERT(dentry->mnt != RT_NULL);
Expand All @@ -1283,7 +1370,7 @@ static int _dfs_lfs_dentry_stat(struct dfs_dentry* dentry, struct stat* st)
static struct dfs_vnode* _dfs_lfs_lookup(struct dfs_dentry* dentry)
{
struct dfs_vnode* vnode;
struct stat st;
DFS_LFS_STAT_TYPE st;

if (dentry == RT_NULL || dentry->mnt == RT_NULL || dentry->mnt->data == RT_NULL)
{
Expand Down