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managed_components/joltwallet__littlefs/src/littlefs/lfs.h
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/*
* The little filesystem
*
* Copyright (c) 2022, The littlefs authors.
* Copyright (c) 2017, Arm Limited. All rights reserved.
* SPDX-License-Identifier: BSD-3-Clause
*/
#ifndef LFS_H
#define LFS_H
#include "lfs_util.h"
#ifdef __cplusplus
extern "C"
{
#endif
/// Version info ///
// Software library version
// Major (top-nibble), incremented on backwards incompatible changes
// Minor (bottom-nibble), incremented on feature additions
#define LFS_VERSION 0x00020009
#define LFS_VERSION_MAJOR (0xffff & (LFS_VERSION >> 16))
#define LFS_VERSION_MINOR (0xffff & (LFS_VERSION >> 0))
// Version of On-disk data structures
// Major (top-nibble), incremented on backwards incompatible changes
// Minor (bottom-nibble), incremented on feature additions
#define LFS_DISK_VERSION 0x00020001
#define LFS_DISK_VERSION_MAJOR (0xffff & (LFS_DISK_VERSION >> 16))
#define LFS_DISK_VERSION_MINOR (0xffff & (LFS_DISK_VERSION >> 0))
/// Definitions ///
// Type definitions
typedef uint32_t lfs_size_t;
typedef uint32_t lfs_off_t;
typedef int32_t lfs_ssize_t;
typedef int32_t lfs_soff_t;
typedef uint32_t lfs_block_t;
// Maximum name size in bytes, may be redefined to reduce the size of the
// info struct. Limited to <= 1022. Stored in superblock and must be
// respected by other littlefs drivers.
#ifndef LFS_NAME_MAX
#define LFS_NAME_MAX 255
#endif
// Maximum size of a file in bytes, may be redefined to limit to support other
// drivers. Limited on disk to <= 2147483647. Stored in superblock and must be
// respected by other littlefs drivers.
#ifndef LFS_FILE_MAX
#define LFS_FILE_MAX 2147483647
#endif
// Maximum size of custom attributes in bytes, may be redefined, but there is
// no real benefit to using a smaller LFS_ATTR_MAX. Limited to <= 1022. Stored
// in superblock and must be respected by other littlefs drivers.
#ifndef LFS_ATTR_MAX
#define LFS_ATTR_MAX 1022
#endif
// Possible error codes, these are negative to allow
// valid positive return values
enum lfs_error {
LFS_ERR_OK = 0, // No error
LFS_ERR_IO = -5, // Error during device operation
LFS_ERR_CORRUPT = -84, // Corrupted
LFS_ERR_NOENT = -2, // No directory entry
LFS_ERR_EXIST = -17, // Entry already exists
LFS_ERR_NOTDIR = -20, // Entry is not a dir
LFS_ERR_ISDIR = -21, // Entry is a dir
LFS_ERR_NOTEMPTY = -39, // Dir is not empty
LFS_ERR_BADF = -9, // Bad file number
LFS_ERR_FBIG = -27, // File too large
LFS_ERR_INVAL = -22, // Invalid parameter
LFS_ERR_NOSPC = -28, // No space left on device
LFS_ERR_NOMEM = -12, // No more memory available
LFS_ERR_NOATTR = -61, // No data/attr available
LFS_ERR_NAMETOOLONG = -36, // File name too long
};
// File types
enum lfs_type {
// file types
LFS_TYPE_REG = 0x001,
LFS_TYPE_DIR = 0x002,
// internally used types
LFS_TYPE_SPLICE = 0x400,
LFS_TYPE_NAME = 0x000,
LFS_TYPE_STRUCT = 0x200,
LFS_TYPE_USERATTR = 0x300,
LFS_TYPE_FROM = 0x100,
LFS_TYPE_TAIL = 0x600,
LFS_TYPE_GLOBALS = 0x700,
LFS_TYPE_CRC = 0x500,
// internally used type specializations
LFS_TYPE_CREATE = 0x401,
LFS_TYPE_DELETE = 0x4ff,
LFS_TYPE_SUPERBLOCK = 0x0ff,
LFS_TYPE_DIRSTRUCT = 0x200,
LFS_TYPE_CTZSTRUCT = 0x202,
LFS_TYPE_INLINESTRUCT = 0x201,
LFS_TYPE_SOFTTAIL = 0x600,
LFS_TYPE_HARDTAIL = 0x601,
LFS_TYPE_MOVESTATE = 0x7ff,
LFS_TYPE_CCRC = 0x500,
LFS_TYPE_FCRC = 0x5ff,
// internal chip sources
LFS_FROM_NOOP = 0x000,
LFS_FROM_MOVE = 0x101,
LFS_FROM_USERATTRS = 0x102,
};
// File open flags
enum lfs_open_flags {
// open flags
LFS_O_RDONLY = 1, // Open a file as read only
#ifndef LFS_READONLY
LFS_O_WRONLY = 2, // Open a file as write only
LFS_O_RDWR = 3, // Open a file as read and write
LFS_O_CREAT = 0x0100, // Create a file if it does not exist
LFS_O_EXCL = 0x0200, // Fail if a file already exists
LFS_O_TRUNC = 0x0400, // Truncate the existing file to zero size
LFS_O_APPEND = 0x0800, // Move to end of file on every write
#endif
// internally used flags
#ifndef LFS_READONLY
LFS_F_DIRTY = 0x010000, // File does not match storage
LFS_F_WRITING = 0x020000, // File has been written since last flush
#endif
LFS_F_READING = 0x040000, // File has been read since last flush
#ifndef LFS_READONLY
LFS_F_ERRED = 0x080000, // An error occurred during write
#endif
LFS_F_INLINE = 0x100000, // Currently inlined in directory entry
};
// File seek flags
enum lfs_whence_flags {
LFS_SEEK_SET = 0, // Seek relative to an absolute position
LFS_SEEK_CUR = 1, // Seek relative to the current file position
LFS_SEEK_END = 2, // Seek relative to the end of the file
};
// Configuration provided during initialization of the littlefs
struct lfs_config {
// Opaque user provided context that can be used to pass
// information to the block device operations
void *context;
// Read a region in a block. Negative error codes are propagated
// to the user.
int (*read)(const struct lfs_config *c, lfs_block_t block,
lfs_off_t off, void *buffer, lfs_size_t size);
// Program a region in a block. The block must have previously
// been erased. Negative error codes are propagated to the user.
// May return LFS_ERR_CORRUPT if the block should be considered bad.
int (*prog)(const struct lfs_config *c, lfs_block_t block,
lfs_off_t off, const void *buffer, lfs_size_t size);
// Erase a block. A block must be erased before being programmed.
// The state of an erased block is undefined. Negative error codes
// are propagated to the user.
// May return LFS_ERR_CORRUPT if the block should be considered bad.
int (*erase)(const struct lfs_config *c, lfs_block_t block);
// Sync the state of the underlying block device. Negative error codes
// are propagated to the user.
int (*sync)(const struct lfs_config *c);
#ifdef LFS_THREADSAFE
// Lock the underlying block device. Negative error codes
// are propagated to the user.
int (*lock)(const struct lfs_config *c);
// Unlock the underlying block device. Negative error codes
// are propagated to the user.
int (*unlock)(const struct lfs_config *c);
#endif
// Minimum size of a block read in bytes. All read operations will be a
// multiple of this value.
lfs_size_t read_size;
// Minimum size of a block program in bytes. All program operations will be
// a multiple of this value.
lfs_size_t prog_size;
// Size of an erasable block in bytes. This does not impact ram consumption
// and may be larger than the physical erase size. However, non-inlined
// files take up at minimum one block. Must be a multiple of the read and
// program sizes.
lfs_size_t block_size;
// Number of erasable blocks on the device. Defaults to block_count stored
// on disk when zero.
lfs_size_t block_count;
// Number of erase cycles before littlefs evicts metadata logs and moves
// the metadata to another block. Suggested values are in the
// range 100-1000, with large values having better performance at the cost
// of less consistent wear distribution.
//
// Set to -1 to disable block-level wear-leveling.
int32_t block_cycles;
// Size of block caches in bytes. Each cache buffers a portion of a block in
// RAM. The littlefs needs a read cache, a program cache, and one additional
// cache per file. Larger caches can improve performance by storing more
// data and reducing the number of disk accesses. Must be a multiple of the
// read and program sizes, and a factor of the block size.
lfs_size_t cache_size;
// Size of the lookahead buffer in bytes. A larger lookahead buffer
// increases the number of blocks found during an allocation pass. The
// lookahead buffer is stored as a compact bitmap, so each byte of RAM
// can track 8 blocks.
lfs_size_t lookahead_size;
// Threshold for metadata compaction during lfs_fs_gc in bytes. Metadata
// pairs that exceed this threshold will be compacted during lfs_fs_gc.
// Defaults to ~88% block_size when zero, though the default may change
// in the future.
//
// Note this only affects lfs_fs_gc. Normal compactions still only occur
// when full.
//
// Set to -1 to disable metadata compaction during lfs_fs_gc.
lfs_size_t compact_thresh;
// Optional statically allocated read buffer. Must be cache_size.
// By default lfs_malloc is used to allocate this buffer.
void *read_buffer;
// Optional statically allocated program buffer. Must be cache_size.
// By default lfs_malloc is used to allocate this buffer.
void *prog_buffer;
// Optional statically allocated lookahead buffer. Must be lookahead_size.
// By default lfs_malloc is used to allocate this buffer.
void *lookahead_buffer;
// Optional upper limit on length of file names in bytes. No downside for
// larger names except the size of the info struct which is controlled by
// the LFS_NAME_MAX define. Defaults to LFS_NAME_MAX or name_max stored on
// disk when zero.
lfs_size_t name_max;
// Optional upper limit on files in bytes. No downside for larger files
// but must be <= LFS_FILE_MAX. Defaults to LFS_FILE_MAX or file_max stored
// on disk when zero.
lfs_size_t file_max;
// Optional upper limit on custom attributes in bytes. No downside for
// larger attributes size but must be <= LFS_ATTR_MAX. Defaults to
// LFS_ATTR_MAX or attr_max stored on disk when zero.
lfs_size_t attr_max;
// Optional upper limit on total space given to metadata pairs in bytes. On
// devices with large blocks (e.g. 128kB) setting this to a low size (2-8kB)
// can help bound the metadata compaction time. Must be <= block_size.
// Defaults to block_size when zero.
lfs_size_t metadata_max;
// Optional upper limit on inlined files in bytes. Inlined files live in
// metadata and decrease storage requirements, but may be limited to
// improve metadata-related performance. Must be <= cache_size, <=
// attr_max, and <= block_size/8. Defaults to the largest possible
// inline_max when zero.
//
// Set to -1 to disable inlined files.
lfs_size_t inline_max;
#ifdef LFS_MULTIVERSION
// On-disk version to use when writing in the form of 16-bit major version
// + 16-bit minor version. This limiting metadata to what is supported by
// older minor versions. Note that some features will be lost. Defaults to
// to the most recent minor version when zero.
uint32_t disk_version;
#endif
};
// File info structure
struct lfs_info {
// Type of the file, either LFS_TYPE_REG or LFS_TYPE_DIR
uint8_t type;
// Size of the file, only valid for REG files. Limited to 32-bits.
lfs_size_t size;
// Name of the file stored as a null-terminated string. Limited to
// LFS_NAME_MAX+1, which can be changed by redefining LFS_NAME_MAX to
// reduce RAM. LFS_NAME_MAX is stored in superblock and must be
// respected by other littlefs drivers.
char name[LFS_NAME_MAX+1];
};
// Filesystem info structure
struct lfs_fsinfo {
// On-disk version.
uint32_t disk_version;
// Size of a logical block in bytes.
lfs_size_t block_size;
// Number of logical blocks in filesystem.
lfs_size_t block_count;
// Upper limit on the length of file names in bytes.
lfs_size_t name_max;
// Upper limit on the size of files in bytes.
lfs_size_t file_max;
// Upper limit on the size of custom attributes in bytes.
lfs_size_t attr_max;
};
// Custom attribute structure, used to describe custom attributes
// committed atomically during file writes.
struct lfs_attr {
// 8-bit type of attribute, provided by user and used to
// identify the attribute
uint8_t type;
// Pointer to buffer containing the attribute
void *buffer;
// Size of attribute in bytes, limited to LFS_ATTR_MAX
lfs_size_t size;
};
// Optional configuration provided during lfs_file_opencfg
struct lfs_file_config {
// Optional statically allocated file buffer. Must be cache_size.
// By default lfs_malloc is used to allocate this buffer.
void *buffer;
// Optional list of custom attributes related to the file. If the file
// is opened with read access, these attributes will be read from disk
// during the open call. If the file is opened with write access, the
// attributes will be written to disk every file sync or close. This
// write occurs atomically with update to the file's contents.
//
// Custom attributes are uniquely identified by an 8-bit type and limited
// to LFS_ATTR_MAX bytes. When read, if the stored attribute is smaller
// than the buffer, it will be padded with zeros. If the stored attribute
// is larger, then it will be silently truncated. If the attribute is not
// found, it will be created implicitly.
struct lfs_attr *attrs;
// Number of custom attributes in the list
lfs_size_t attr_count;
};
/// internal littlefs data structures ///
typedef struct lfs_cache {
lfs_block_t block;
lfs_off_t off;
lfs_size_t size;
uint8_t *buffer;
} lfs_cache_t;
typedef struct lfs_mdir {
lfs_block_t pair[2];
uint32_t rev;
lfs_off_t off;
uint32_t etag;
uint16_t count;
bool erased;
bool split;
lfs_block_t tail[2];
} lfs_mdir_t;
// littlefs directory type
typedef struct lfs_dir {
struct lfs_dir *next;
uint16_t id;
uint8_t type;
lfs_mdir_t m;
lfs_off_t pos;
lfs_block_t head[2];
} lfs_dir_t;
// littlefs file type
typedef struct lfs_file {
struct lfs_file *next;
uint16_t id;
uint8_t type;
lfs_mdir_t m;
struct lfs_ctz {
lfs_block_t head;
lfs_size_t size;
} ctz;
uint32_t flags;
lfs_off_t pos;
lfs_block_t block;
lfs_off_t off;
lfs_cache_t cache;
const struct lfs_file_config *cfg;
} lfs_file_t;
typedef struct lfs_superblock {
uint32_t version;
lfs_size_t block_size;
lfs_size_t block_count;
lfs_size_t name_max;
lfs_size_t file_max;
lfs_size_t attr_max;
} lfs_superblock_t;
typedef struct lfs_gstate {
uint32_t tag;
lfs_block_t pair[2];
} lfs_gstate_t;
// The littlefs filesystem type
typedef struct lfs {
lfs_cache_t rcache;
lfs_cache_t pcache;
lfs_block_t root[2];
struct lfs_mlist {
struct lfs_mlist *next;
uint16_t id;
uint8_t type;
lfs_mdir_t m;
} *mlist;
uint32_t seed;
lfs_gstate_t gstate;
lfs_gstate_t gdisk;
lfs_gstate_t gdelta;
struct lfs_lookahead {
lfs_block_t start;
lfs_block_t size;
lfs_block_t next;
lfs_block_t ckpoint;
uint8_t *buffer;
} lookahead;
const struct lfs_config *cfg;
lfs_size_t block_count;
lfs_size_t name_max;
lfs_size_t file_max;
lfs_size_t attr_max;
lfs_size_t inline_max;
#ifdef LFS_MIGRATE
struct lfs1 *lfs1;
#endif
} lfs_t;
/// Filesystem functions ///
#ifndef LFS_READONLY
// Format a block device with the littlefs
//
// Requires a littlefs object and config struct. This clobbers the littlefs
// object, and does not leave the filesystem mounted. The config struct must
// be zeroed for defaults and backwards compatibility.
//
// Returns a negative error code on failure.
int lfs_format(lfs_t *lfs, const struct lfs_config *config);
#endif
// Mounts a littlefs
//
// Requires a littlefs object and config struct. Multiple filesystems
// may be mounted simultaneously with multiple littlefs objects. Both
// lfs and config must be allocated while mounted. The config struct must
// be zeroed for defaults and backwards compatibility.
//
// Returns a negative error code on failure.
int lfs_mount(lfs_t *lfs, const struct lfs_config *config);
// Unmounts a littlefs
//
// Does nothing besides releasing any allocated resources.
// Returns a negative error code on failure.
int lfs_unmount(lfs_t *lfs);
/// General operations ///
#ifndef LFS_READONLY
// Removes a file or directory
//
// If removing a directory, the directory must be empty.
// Returns a negative error code on failure.
int lfs_remove(lfs_t *lfs, const char *path);
#endif
#ifndef LFS_READONLY
// Rename or move a file or directory
//
// If the destination exists, it must match the source in type.
// If the destination is a directory, the directory must be empty.
//
// Returns a negative error code on failure.
int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath);
#endif
// Find info about a file or directory
//
// Fills out the info structure, based on the specified file or directory.
// Returns a negative error code on failure.
int lfs_stat(lfs_t *lfs, const char *path, struct lfs_info *info);
// Get a custom attribute
//
// Custom attributes are uniquely identified by an 8-bit type and limited
// to LFS_ATTR_MAX bytes. When read, if the stored attribute is smaller than
// the buffer, it will be padded with zeros. If the stored attribute is larger,
// then it will be silently truncated. If no attribute is found, the error
// LFS_ERR_NOATTR is returned and the buffer is filled with zeros.
//
// Returns the size of the attribute, or a negative error code on failure.
// Note, the returned size is the size of the attribute on disk, irrespective
// of the size of the buffer. This can be used to dynamically allocate a buffer
// or check for existence.
lfs_ssize_t lfs_getattr(lfs_t *lfs, const char *path,
uint8_t type, void *buffer, lfs_size_t size);
#ifndef LFS_READONLY
// Set custom attributes
//
// Custom attributes are uniquely identified by an 8-bit type and limited
// to LFS_ATTR_MAX bytes. If an attribute is not found, it will be
// implicitly created.
//
// Returns a negative error code on failure.
int lfs_setattr(lfs_t *lfs, const char *path,
uint8_t type, const void *buffer, lfs_size_t size);
#endif
#ifndef LFS_READONLY
// Removes a custom attribute
//
// If an attribute is not found, nothing happens.
//
// Returns a negative error code on failure.
int lfs_removeattr(lfs_t *lfs, const char *path, uint8_t type);
#endif
/// File operations ///
#ifndef LFS_NO_MALLOC
// Open a file
//
// The mode that the file is opened in is determined by the flags, which
// are values from the enum lfs_open_flags that are bitwise-ored together.
//
// Returns a negative error code on failure.
int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
const char *path, int flags);
// if LFS_NO_MALLOC is defined, lfs_file_open() will fail with LFS_ERR_NOMEM
// thus use lfs_file_opencfg() with config.buffer set.
#endif
// Open a file with extra configuration
//
// The mode that the file is opened in is determined by the flags, which
// are values from the enum lfs_open_flags that are bitwise-ored together.
//
// The config struct provides additional config options per file as described
// above. The config struct must remain allocated while the file is open, and
// the config struct must be zeroed for defaults and backwards compatibility.
//
// Returns a negative error code on failure.
int lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
const char *path, int flags,
const struct lfs_file_config *config);
// Close a file
//
// Any pending writes are written out to storage as though
// sync had been called and releases any allocated resources.
//
// Returns a negative error code on failure.
int lfs_file_close(lfs_t *lfs, lfs_file_t *file);
// Synchronize a file on storage
//
// Any pending writes are written out to storage.
// Returns a negative error code on failure.
int lfs_file_sync(lfs_t *lfs, lfs_file_t *file);
// Read data from file
//
// Takes a buffer and size indicating where to store the read data.
// Returns the number of bytes read, or a negative error code on failure.
lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
void *buffer, lfs_size_t size);
#ifndef LFS_READONLY
// Write data to file
//
// Takes a buffer and size indicating the data to write. The file will not
// actually be updated on the storage until either sync or close is called.
//
// Returns the number of bytes written, or a negative error code on failure.
lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
const void *buffer, lfs_size_t size);
#endif
// Change the position of the file
//
// The change in position is determined by the offset and whence flag.
// Returns the new position of the file, or a negative error code on failure.
lfs_soff_t lfs_file_seek(lfs_t *lfs, lfs_file_t *file,
lfs_soff_t off, int whence);
#ifndef LFS_READONLY
// Truncates the size of the file to the specified size
//
// Returns a negative error code on failure.
int lfs_file_truncate(lfs_t *lfs, lfs_file_t *file, lfs_off_t size);
#endif
// Return the position of the file
//
// Equivalent to lfs_file_seek(lfs, file, 0, LFS_SEEK_CUR)
// Returns the position of the file, or a negative error code on failure.
lfs_soff_t lfs_file_tell(lfs_t *lfs, lfs_file_t *file);
// Change the position of the file to the beginning of the file
//
// Equivalent to lfs_file_seek(lfs, file, 0, LFS_SEEK_SET)
// Returns a negative error code on failure.
int lfs_file_rewind(lfs_t *lfs, lfs_file_t *file);
// Return the size of the file
//
// Similar to lfs_file_seek(lfs, file, 0, LFS_SEEK_END)
// Returns the size of the file, or a negative error code on failure.
lfs_soff_t lfs_file_size(lfs_t *lfs, lfs_file_t *file);
/// Directory operations ///
#ifndef LFS_READONLY
// Create a directory
//
// Returns a negative error code on failure.
int lfs_mkdir(lfs_t *lfs, const char *path);
#endif
// Open a directory
//
// Once open a directory can be used with read to iterate over files.
// Returns a negative error code on failure.
int lfs_dir_open(lfs_t *lfs, lfs_dir_t *dir, const char *path);
// Close a directory
//
// Releases any allocated resources.
// Returns a negative error code on failure.
int lfs_dir_close(lfs_t *lfs, lfs_dir_t *dir);
// Read an entry in the directory
//
// Fills out the info structure, based on the specified file or directory.
// Returns a positive value on success, 0 at the end of directory,
// or a negative error code on failure.
int lfs_dir_read(lfs_t *lfs, lfs_dir_t *dir, struct lfs_info *info);
// Change the position of the directory
//
// The new off must be a value previous returned from tell and specifies
// an absolute offset in the directory seek.
//
// Returns a negative error code on failure.
int lfs_dir_seek(lfs_t *lfs, lfs_dir_t *dir, lfs_off_t off);
// Return the position of the directory
//
// The returned offset is only meant to be consumed by seek and may not make
// sense, but does indicate the current position in the directory iteration.
//
// Returns the position of the directory, or a negative error code on failure.
lfs_soff_t lfs_dir_tell(lfs_t *lfs, lfs_dir_t *dir);
// Change the position of the directory to the beginning of the directory
//
// Returns a negative error code on failure.
int lfs_dir_rewind(lfs_t *lfs, lfs_dir_t *dir);
/// Filesystem-level filesystem operations
// Find on-disk info about the filesystem
//
// Fills out the fsinfo structure based on the filesystem found on-disk.
// Returns a negative error code on failure.
int lfs_fs_stat(lfs_t *lfs, struct lfs_fsinfo *fsinfo);
// Finds the current size of the filesystem
//
// Note: Result is best effort. If files share COW structures, the returned
// size may be larger than the filesystem actually is.
//
// Returns the number of allocated blocks, or a negative error code on failure.
lfs_ssize_t lfs_fs_size(lfs_t *lfs);
// Traverse through all blocks in use by the filesystem
//
// The provided callback will be called with each block address that is
// currently in use by the filesystem. This can be used to determine which
// blocks are in use or how much of the storage is available.
//
// Returns a negative error code on failure.
int lfs_fs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data);
#ifndef LFS_READONLY
// Attempt to make the filesystem consistent and ready for writing
//
// Calling this function is not required, consistency will be implicitly
// enforced on the first operation that writes to the filesystem, but this
// function allows the work to be performed earlier and without other
// filesystem changes.
//
// Returns a negative error code on failure.
int lfs_fs_mkconsistent(lfs_t *lfs);
#endif
#ifndef LFS_READONLY
// Attempt any janitorial work
//
// This currently:
// 1. Calls mkconsistent if not already consistent
// 2. Compacts metadata > compact_thresh
// 3. Populates the block allocator
//
// Though additional janitorial work may be added in the future.
//
// Calling this function is not required, but may allow the offloading of
// expensive janitorial work to a less time-critical code path.
//
// Returns a negative error code on failure. Accomplishing nothing is not
// an error.
int lfs_fs_gc(lfs_t *lfs);
#endif
#ifndef LFS_READONLY
// Grows the filesystem to a new size, updating the superblock with the new
// block count.
//
// Note: This is irreversible.
//
// Returns a negative error code on failure.
int lfs_fs_grow(lfs_t *lfs, lfs_size_t block_count);
#endif
#ifndef LFS_READONLY
#ifdef LFS_MIGRATE
// Attempts to migrate a previous version of littlefs
//
// Behaves similarly to the lfs_format function. Attempts to mount
// the previous version of littlefs and update the filesystem so it can be
// mounted with the current version of littlefs.
//
// Requires a littlefs object and config struct. This clobbers the littlefs
// object, and does not leave the filesystem mounted. The config struct must
// be zeroed for defaults and backwards compatibility.
//
// Returns a negative error code on failure.
int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg);
#endif
#endif
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif
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