/**
******************************************************************************
* @file pios_flashfs_logfs.c
* @author PhoenixPilot, http://github.com/PhoenixPilot, Copyright (C) 2012
* @addtogroup PIOS PIOS Core hardware abstraction layer
* @{
* @addtogroup PIOS_FLASHFS Flash Filesystem Function
* @{
* @brief Log Structured Filesystem for internal or external NOR Flash
*****************************************************************************/
/*
* This program 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.
*
* This program 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 this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "pios.h"
#ifdef PIOS_INCLUDE_FLASH
#include <stdbool.h>
#include <openpilot.h>
#include <pios_math.h>
#include <pios_wdg.h>
#include "pios_flashfs_logfs_priv.h"
/*
* Filesystem state data tracked in RAM
*/
enum pios_flashfs_logfs_dev_magic {
PIOS_FLASHFS_LOGFS_DEV_MAGIC = 0x94938201,
};
struct logfs_state {
enum pios_flashfs_logfs_dev_magic magic;
const struct flashfs_logfs_cfg *cfg;
bool mounted;
uint8_t active_arena_id;
/* NOTE: num_active_slots + num_free_slots will not typically add
* up to the number of slots in the arena since some of the
* slots will be obsolete or otherwise invalidated
*/
uint16_t num_free_slots; /* slots in free state */
uint16_t num_active_slots; /* slots in active state */
/* Underlying flash driver glue */
const struct pios_flash_driver *driver;
uintptr_t flash_id;
};
/*
* Internal Utility functions
*/
/**
* @brief Return the offset in flash of a particular slot within an arena
* @return address of the requested slot
*/
static uintptr_t logfs_get_addr(const struct logfs_state *logfs, uint8_t arena_id, uint16_t slot_id)
{
PIOS_Assert(arena_id < (logfs->cfg->total_fs_size / logfs->cfg->arena_size));
PIOS_Assert(slot_id < (logfs->cfg->arena_size / logfs->cfg->slot_size));
return logfs->cfg->start_offset +
(arena_id * logfs->cfg->arena_size) +
(slot_id * logfs->cfg->slot_size);
}
/*
* The bits within these enum values must progress ONLY
* from 1 -> 0 so that we can write later ones on top
* of earlier ones in NOR flash without an erase cycle.
*/
enum arena_state {
/*
* The STM32F30X flash subsystem is only capable of
* writing words or halfwords. In this case we use halfwords.
* In addition to that it is only capable to write to erased
* cells (0xffff) or write a cell from anything to (0x0000).
* To cope with this, the F3 needs carefully crafted enum values.
* For this to work the underlying flash driver has to
* check each halfword if it has changed before writing.
*/
ARENA_STATE_ERASED = 0xFFFFFFFF,
ARENA_STATE_RESERVED = 0xE6E6FFFF,
ARENA_STATE_ACTIVE = 0xE6E66666,
ARENA_STATE_OBSOLETE = 0x00000000,
};
struct arena_header {
uint32_t magic;
enum arena_state state;
} __attribute__((packed));
/****************************************
* Arena life-cycle transition functions
****************************************/
/**
* @brief Erases all sectors within the given arena and sets arena to erased state.
* @return 0 if success, < 0 on failure
* @note Must be called while holding the flash transaction lock
*/
static int32_t logfs_erase_arena(const struct logfs_state *logfs, uint8_t arena_id)
{
uintptr_t arena_addr = logfs_get_addr(logfs, arena_id, 0);
/* Erase all of the sectors in the arena */
for (uint8_t sector_id = 0;
sector_id < (logfs->cfg->arena_size / logfs->cfg->sector_size);
sector_id++) {
if (logfs->driver->erase_sector(logfs->flash_id,
arena_addr + (sector_id * logfs->cfg->sector_size))) {
return -1;
}
}
/* Mark this arena as fully erased */
struct arena_header arena_hdr = {
.magic = logfs->cfg->fs_magic,
.state = ARENA_STATE_ERASED,
};
if (logfs->driver->write_data(logfs->flash_id,
arena_addr,
(uint8_t *)&arena_hdr,
sizeof(arena_hdr)) != 0) {
return -2;
}
/* Arena is ready to be activated */
return 0;
}
/**
* @brief Marks the given arena as reserved so it can be filled.
* @return 0 if success, < 0 on failure
* @note Arena must have been previously erased before calling this
* @note Must be called while holding the flash transaction lock
*/
static int32_t logfs_reserve_arena(const struct logfs_state *logfs, uint8_t arena_id)
{
uintptr_t arena_addr = logfs_get_addr(logfs, arena_id, 0);
/* Read in the current arena header */
struct arena_header arena_hdr;
if (logfs->driver->read_data(logfs->flash_id,
arena_addr,
(uint8_t *)&arena_hdr,
sizeof(arena_hdr)) != 0) {
return -1;
}
if (arena_hdr.state != ARENA_STATE_ERASED) {
/* Arena was not erased, can't reserve it */
return -2;
}
/* Set the arena state to reserved */
arena_hdr.state = ARENA_STATE_RESERVED;
/* Write the arena header back to flash */
if (logfs->driver->write_data(logfs->flash_id,
arena_addr,
(uint8_t *)&arena_hdr,
sizeof(arena_hdr)) != 0) {
return -3;
}
/* Arena is ready to be filled */
return 0;
}
/**
* @brief Erases all arenas available to this filesystem instance
* @return 0 if success, < 0 on failure
* @note Must be called while holding the flash transaction lock
*/
static int32_t logfs_erase_all_arenas(const struct logfs_state *logfs)
{
uint16_t num_arenas = logfs->cfg->total_fs_size / logfs->cfg->arena_size;
for (uint16_t arena = 0; arena < num_arenas; arena++) {
#ifdef PIOS_LED_HEARTBEAT
PIOS_LED_Toggle(PIOS_LED_HEARTBEAT);
#endif
#ifdef PIOS_INCLUDE_WDG
PIOS_WDG_Clear();
#endif
if (logfs_erase_arena(logfs, arena) != 0) {
return -1;
}
}
return 0;
}
/**
* @brief Marks the given arena as active so it can be mounted.
* @return 0 if success, < 0 on failure
* @note Arena must have been previously erased or reserved before calling this
* @note Must be called while holding the flash transaction lock
*/
static int32_t logfs_activate_arena(const struct logfs_state *logfs, uint8_t arena_id)
{
uintptr_t arena_addr = logfs_get_addr(logfs, arena_id, 0);
/* Make sure this arena has been previously erased */
struct arena_header arena_hdr;
if (logfs->driver->read_data(logfs->flash_id,
arena_addr,
(uint8_t *)&arena_hdr,
sizeof(arena_hdr)) != 0) {
/* Failed to read arena header */
return -1;
}
if ((arena_hdr.state != ARENA_STATE_RESERVED) &&
(arena_hdr.state != ARENA_STATE_ERASED)) {
/* Arena was not erased or reserved, can't activate it */
return -2;
}
/* Mark this arena as active */
arena_hdr.state = ARENA_STATE_ACTIVE;
if (logfs->driver->write_data(logfs->flash_id,
arena_addr,
(uint8_t *)&arena_hdr,
sizeof(arena_hdr)) != 0) {
return -3;
}
/* The arena is now activated and the log may be mounted */
return 0;
}
/**
* @brief Marks the given arena as obsolete.
* @return 0 if success, < 0 on failure
* @note Arena must have been previously active before calling this
* @note Must be called while holding the flash transaction lock
*/
static int32_t logfs_obsolete_arena(const struct logfs_state *logfs, uint8_t arena_id)
{
uintptr_t arena_addr = logfs_get_addr(logfs, arena_id, 0);
/* We shouldn't be retiring the currently active arena */
PIOS_Assert(!logfs->mounted);
/* Make sure this arena was previously active */
struct arena_header arena_hdr;
if (logfs->driver->read_data(logfs->flash_id,
arena_addr,
(uint8_t *)&arena_hdr,
sizeof(arena_hdr)) != 0) {
/* Failed to read arena header */
return -1;
}
if (arena_hdr.state != ARENA_STATE_ACTIVE) {
/* Arena was not previously active, can't obsolete it */
return -2;
}
/* Mark this arena as obsolete */
arena_hdr.state = ARENA_STATE_OBSOLETE;
if (logfs->driver->write_data(logfs->flash_id,
arena_addr,
(uint8_t *)&arena_hdr,
sizeof(arena_hdr)) != 0) {
return -3;
}
/* Arena is now obsoleted */
return 0;
}
/**
* @brief Find the first active arena in flash
* @return arena_id (>=0) of first active arena
* @return -1 if no active arena is found
* @return -2 if failed to read arena header
* @note Must be called while holding the flash transaction lock
*/
static int32_t logfs_find_active_arena(const struct logfs_state *logfs)
{
/* Search for the lowest numbered active arena */
for (uint8_t arena_id = 0;
arena_id < logfs->cfg->total_fs_size / logfs->cfg->arena_size;
arena_id++) {
uintptr_t arena_addr = logfs_get_addr(logfs, arena_id, 0);
/* Load the arena header */
struct arena_header arena_hdr;
if (logfs->driver->read_data(logfs->flash_id,
arena_addr,
(uint8_t *)&arena_hdr,
sizeof(arena_hdr)) != 0) {
return -2;
}
if ((arena_hdr.state == ARENA_STATE_ACTIVE) &&
(arena_hdr.magic == logfs->cfg->fs_magic)) {
/* This is the first active arena */
return arena_id;
}
#ifdef PIOS_INCLUDE_WDG
PIOS_WDG_Clear();
#endif
}
/* Didn't find an active arena */
return -1;
}
/*
* The bits within these enum values must progress ONLY
* from 1 -> 0 so that we can write later ones on top
* of earlier ones in NOR flash without an erase cycle.
*/
enum slot_state {
/*
* The STM32F30X flash subsystem is only capable of
* writing words or halfwords. In this case we use halfwords.
* In addition to that it is only capable to write to erased
* cells (0xffff) or write a cell from anything to (0x0000).
* To cope with this, the F3 needs carfully crafted enum values.
* For this to work the underlying flash driver has to
* check each halfword if it has changed before writing.
*/
SLOT_STATE_EMPTY = 0xFFFFFFFF,
SLOT_STATE_RESERVED = 0xFAFAFFFF,
SLOT_STATE_ACTIVE = 0xFAFAAAAA,
SLOT_STATE_OBSOLETE = 0x00000000,
};
struct slot_header {
enum slot_state state;
uint32_t obj_id;
uint16_t obj_inst_id;
uint16_t obj_size;
} __attribute__((packed));
/* NOTE: Must be called while holding the flash transaction lock */
static int32_t logfs_raw_copy_bytes(const struct logfs_state *logfs, uintptr_t src_addr, uint16_t src_size, uintptr_t dst_addr)
{
#define RAW_COPY_BLOCK_SIZE 16
uint8_t data_block[RAW_COPY_BLOCK_SIZE];
while (src_size) {
uint16_t blk_size;
if (src_size >= RAW_COPY_BLOCK_SIZE) {
/* Copy a full block */
blk_size = RAW_COPY_BLOCK_SIZE;
} else {
/* Copy the remainder */
blk_size = src_size;
}
/* Read a block of data from source */
if (logfs->driver->read_data(logfs->flash_id,
src_addr,
data_block,
blk_size) != 0) {
/* Failed to read next chunk from source */
return -1;
}
/* Write a block of data to destination */
if (logfs->driver->write_data(logfs->flash_id,
dst_addr,
data_block,
blk_size) != 0) {
/* Failed to write chunk to destination */
return -2;
}
/* Update the src/dst pointers */
src_size -= blk_size;
src_addr += blk_size;
dst_addr += blk_size;
}
return 0;
}
/*
* Is the entire filesystem full?
* true = all slots in the arena are in the ACTIVE state (ie. garbage collection won't free anything)
* false = some slots in the arena are either currently free or could be free'd by garbage collection
*/
static bool logfs_fs_is_full(const struct logfs_state *logfs)
{
return logfs->num_active_slots == (logfs->cfg->arena_size / logfs->cfg->slot_size) - 1;
}
/*
* Is the log full?
* true = there are no unwritten slots left in the log (garbage collection may or may not help)
* false = there are still some entirely unused slots left in the log
*/
static bool logfs_log_is_full(const struct logfs_state *logfs)
{
return logfs->num_free_slots == 0;
}
static int32_t logfs_unmount_log(struct logfs_state *logfs)
{
PIOS_Assert(logfs->mounted);
logfs->num_active_slots = 0;
logfs->num_free_slots = 0;
logfs->mounted = false;
return 0;
}
static int32_t logfs_mount_log(struct logfs_state *logfs, uint8_t arena_id)
{
PIOS_Assert(!logfs->mounted);
logfs->num_active_slots = 0;
logfs->num_free_slots = 0;
logfs->active_arena_id = arena_id;
/* Scan the log to find out how full it is */
for (uint16_t slot_id = 1;
slot_id < (logfs->cfg->arena_size / logfs->cfg->slot_size);
slot_id++) {
struct slot_header slot_hdr;
uintptr_t slot_addr = logfs_get_addr(logfs, logfs->active_arena_id, slot_id);
if (logfs->driver->read_data(logfs->flash_id,
slot_addr,
(uint8_t *)&slot_hdr,
sizeof(slot_hdr)) != 0) {
return -1;
}
/*
* Empty slots must be in a continguous block at the
* end of the arena.
*/
PIOS_Assert(slot_hdr.state == SLOT_STATE_EMPTY ||
logfs->num_free_slots == 0);
switch (slot_hdr.state) {
case SLOT_STATE_EMPTY:
logfs->num_free_slots++;
break;
case SLOT_STATE_ACTIVE:
logfs->num_active_slots++;
break;
case SLOT_STATE_RESERVED:
case SLOT_STATE_OBSOLETE:
break;
}
}
/* Scan is complete, mark the arena mounted */
logfs->active_arena_id = arena_id;
logfs->mounted = true;
return 0;
}
static bool PIOS_FLASHFS_Logfs_validate(const struct logfs_state *logfs)
{
return logfs && (logfs->magic == PIOS_FLASHFS_LOGFS_DEV_MAGIC);
}
#if defined(PIOS_INCLUDE_FREERTOS)
static struct logfs_state *PIOS_FLASHFS_Logfs_alloc(void)
{
struct logfs_state *logfs;
logfs = (struct logfs_state *)pvPortMalloc(sizeof(*logfs));
if (!logfs) {
return NULL;
}
logfs->magic = PIOS_FLASHFS_LOGFS_DEV_MAGIC;
return logfs;
}
static void PIOS_FLASHFS_Logfs_free(struct logfs_state *logfs)
{
/* Invalidate the magic */
logfs->magic = ~PIOS_FLASHFS_LOGFS_DEV_MAGIC;
vPortFree(logfs);
}
#else
static struct logfs_state pios_flashfs_logfs_devs[PIOS_FLASHFS_LOGFS_MAX_DEVS];
static uint8_t pios_flashfs_logfs_num_devs;
static struct logfs_state *PIOS_FLASHFS_Logfs_alloc(void)
{
struct logfs_state *logfs;
if (pios_flashfs_logfs_num_devs >= PIOS_FLASHFS_LOGFS_MAX_DEVS) {
return NULL;
}
logfs = &pios_flashfs_logfs_devs[pios_flashfs_logfs_num_devs++];
logfs->magic = PIOS_FLASHFS_LOGFS_DEV_MAGIC;
return logfs;
}
static void PIOS_FLASHFS_Logfs_free(struct logfs_state *logfs)
{
/* Invalidate the magic */
logfs->magic = ~PIOS_FLASHFS_LOGFS_DEV_MAGIC;
/* Can't free the resources with this simple allocator */
}
#endif /* if defined(PIOS_INCLUDE_FREERTOS) */
/**
* @brief Initialize the flash object setting FS
* @return 0 if success, -1 if failure
*/
int32_t PIOS_FLASHFS_Logfs_Init(uintptr_t *fs_id, const struct flashfs_logfs_cfg *cfg, const struct pios_flash_driver *driver, uintptr_t flash_id)
{
PIOS_Assert(cfg);
PIOS_Assert(fs_id);
PIOS_Assert(driver);
/* We must have at least 2 arenas for garbage collection to work */
PIOS_Assert((cfg->total_fs_size / cfg->arena_size > 1));
/* Make sure the underlying flash driver provides the minimal set of required methods */
PIOS_Assert(driver->start_transaction);
PIOS_Assert(driver->end_transaction);
PIOS_Assert(driver->erase_sector);
PIOS_Assert(driver->write_data);
PIOS_Assert(driver->read_data);
int8_t rc;
struct logfs_state *logfs;
logfs = (struct logfs_state *)PIOS_FLASHFS_Logfs_alloc();
if (!logfs) {
rc = -1;
goto out_exit;
}
/* Bind configuration parameters to this filesystem instance */
logfs->cfg = cfg; /* filesystem configuration */
logfs->driver = driver; /* lower-level flash driver */
logfs->flash_id = flash_id; /* lower-level flash device id */
logfs->mounted = false;
if (logfs->driver->start_transaction(logfs->flash_id) != 0) {
rc = -1;
goto out_exit;
}
bool found = false;
int32_t arena_id;
for (uint8_t try = 0; !found && try < 2; try++) {
/* Find the active arena */
arena_id = logfs_find_active_arena(logfs);
if (arena_id >= 0) {
/* Found the active arena */
found = true;
break;
} else {
/* No active arena found, erase and activate arena 0 */
if (logfs_erase_arena(logfs, 0) != 0) {
break;
}
if (logfs_activate_arena(logfs, 0) != 0) {
break;
}
}
}
if (!found) {
/* Still no active arena, something is broken */
rc = -2;
goto out_end_trans;
}
/* We've found an active arena, mount it */
if (logfs_mount_log(logfs, arena_id) != 0) {
/* Failed to mount the log, something is broken */
rc = -3;
goto out_end_trans;
}
/* Log has been mounted */
rc = 0;
*fs_id = (uintptr_t)logfs;
out_end_trans:
logfs->driver->end_transaction(logfs->flash_id);
out_exit:
return rc;
}
int32_t PIOS_FLASHFS_Logfs_Destroy(uintptr_t fs_id)
{
int32_t rc;
struct logfs_state *logfs = (struct logfs_state *)fs_id;
if (!PIOS_FLASHFS_Logfs_validate(logfs)) {
rc = -1;
goto out_exit;
}
PIOS_FLASHFS_Logfs_free(logfs);
rc = 0;
out_exit:
return rc;
}
/* NOTE: Must be called while holding the flash transaction lock */
static int32_t logfs_garbage_collect(struct logfs_state *logfs)
{
PIOS_Assert(logfs->mounted);
/* Source arena is the active arena */
uint8_t src_arena_id = logfs->active_arena_id;
/* Compute destination arena */
uint8_t dst_arena_id = (logfs->active_arena_id + 1) % (logfs->cfg->total_fs_size / logfs->cfg->arena_size);
/* Erase destination arena */
if (logfs_erase_arena(logfs, dst_arena_id) != 0) {
return -1;
}
/* Reserve the destination arena so we can start filling it */
if (logfs_reserve_arena(logfs, dst_arena_id) != 0) {
/* Unable to reserve the arena */
return -2;
}
/* Copy active slots from active arena to destination arena */
uint16_t dst_slot_id = 1;
for (uint16_t src_slot_id = 1;
src_slot_id < (logfs->cfg->arena_size / logfs->cfg->slot_size);
src_slot_id++) {
struct slot_header slot_hdr;
uintptr_t src_addr = logfs_get_addr(logfs, src_arena_id, src_slot_id);
if (logfs->driver->read_data(logfs->flash_id,
src_addr,
(uint8_t *)&slot_hdr,
sizeof(slot_hdr)) != 0) {
return -3;
}
if (slot_hdr.state == SLOT_STATE_ACTIVE) {
uintptr_t dst_addr = logfs_get_addr(logfs, dst_arena_id, dst_slot_id);
if (logfs_raw_copy_bytes(logfs,
src_addr,
sizeof(slot_hdr) + slot_hdr.obj_size,
dst_addr) != 0) {
/* Failed to copy all bytes */
return -4;
}
dst_slot_id++;
}
#ifdef PIOS_INCLUDE_WDG
PIOS_WDG_Clear();
#endif
}
/* Activate the destination arena */
if (logfs_activate_arena(logfs, dst_arena_id) != 0) {
return -5;
}
/* Unmount the source arena */
if (logfs_unmount_log(logfs) != 0) {
return -6;
}
/* Obsolete the source arena */
if (logfs_obsolete_arena(logfs, src_arena_id) != 0) {
return -7;
}
/* Mount the new arena */
if (logfs_mount_log(logfs, dst_arena_id) != 0) {
return -8;
}
return 0;
}
/* NOTE: Must be called while holding the flash transaction lock */
static int16_t logfs_object_find_next(const struct logfs_state *logfs, struct slot_header *slot_hdr, uint16_t *curr_slot, uint32_t obj_id, uint16_t obj_inst_id)
{
PIOS_Assert(slot_hdr);
PIOS_Assert(curr_slot);
/* First slot in the arena is reserved for arena header, skip it. */
if (*curr_slot == 0) {
*curr_slot = 1;
}
for (uint16_t slot_id = *curr_slot;
slot_id < (logfs->cfg->arena_size / logfs->cfg->slot_size);
slot_id++) {
uintptr_t slot_addr = logfs_get_addr(logfs, logfs->active_arena_id, slot_id);
if (logfs->driver->read_data(logfs->flash_id,
slot_addr,
(uint8_t *)slot_hdr,
sizeof(*slot_hdr)) != 0) {
return -2;
}
if (slot_hdr->state == SLOT_STATE_EMPTY) {
/* We hit the end of the log */
break;
}
if (slot_hdr->state == SLOT_STATE_ACTIVE &&
slot_hdr->obj_id == obj_id &&
slot_hdr->obj_inst_id == obj_inst_id) {
/* Found what we were looking for */
*curr_slot = slot_id;
return 0;
}
#ifdef PIOS_INCLUDE_WDG
PIOS_WDG_Clear();
#endif
}
/* No matching entry was found */
return -1;
}
/* NOTE: Must be called while holding the flash transaction lock */
/* OPTIMIZE: could trust that there is at most one active version of every object and terminate the search when we find one */
static int8_t logfs_delete_object(struct logfs_state *logfs, uint32_t obj_id, uint16_t obj_inst_id)
{
int8_t rc;
bool more = true;
uint16_t curr_slot_id = 0;
do {
struct slot_header slot_hdr;
switch (logfs_object_find_next(logfs, &slot_hdr, &curr_slot_id, obj_id, obj_inst_id)) {
case 0:
/* Found a matching slot. Obsolete it. */
slot_hdr.state = SLOT_STATE_OBSOLETE;
uintptr_t slot_addr = logfs_get_addr(logfs, logfs->active_arena_id, curr_slot_id);
if (logfs->driver->write_data(logfs->flash_id,
slot_addr,
(uint8_t *)&slot_hdr,
sizeof(slot_hdr)) != 0) {
rc = -2;
goto out_exit;
}
/* Object has been successfully obsoleted and is no longer active */
logfs->num_active_slots--;
break;
case -1:
/* Search completed, object not found */
more = false;
rc = 0;
break;
default:
/* Error occurred during search */
rc = -1;
goto out_exit;
}
} while (more);
out_exit:
return rc;
}
/* NOTE: Must be called while holding the flash transaction lock */
static int8_t logfs_reserve_free_slot(struct logfs_state *logfs, uint16_t *slot_id, struct slot_header *slot_hdr, uint32_t obj_id, uint16_t obj_inst_id, uint16_t obj_size)
{
PIOS_Assert(slot_id);
PIOS_Assert(slot_hdr);
if (logfs->num_free_slots < 1) {
/* No free slots to allocate */
return -1;
}
if (obj_size > (logfs->cfg->slot_size - sizeof(slot_hdr))) {
/* This object is too big for the slot */
return -2;
}
uint16_t candidate_slot_id = (logfs->cfg->arena_size / logfs->cfg->slot_size) - logfs->num_free_slots;
PIOS_Assert(candidate_slot_id > 0);
uintptr_t slot_addr = logfs_get_addr(logfs, logfs->active_arena_id, candidate_slot_id);
if (logfs->driver->read_data(logfs->flash_id,
slot_addr,
(uint8_t *)slot_hdr,
sizeof(*slot_hdr)) != 0) {
/* Failed to read slot header for candidate slot */
return -3;
}
if (slot_hdr->state != SLOT_STATE_EMPTY) {
/* Candidate slot isn't empty! Something is broken. */
PIOS_DEBUG_Assert(0);
return -4;
}
/* Mark this slot as RESERVED */
slot_hdr->state = SLOT_STATE_RESERVED;
slot_hdr->obj_id = obj_id;
slot_hdr->obj_inst_id = obj_inst_id;
slot_hdr->obj_size = obj_size;
if (logfs->driver->write_data(logfs->flash_id,
slot_addr,
(uint8_t *)slot_hdr,
sizeof(*slot_hdr)) != 0) {
/* Failed to write the slot header */
return -5;
}
/* FIXME: If the header write (above) failed, may have partially written data, thus corrupting that slot but we would have missed decrementing this counter */
logfs->num_free_slots--;
*slot_id = candidate_slot_id;
return 0;
}
/* NOTE: Must be called while holding the flash transaction lock */
static int8_t logfs_append_to_log(struct logfs_state *logfs, uint32_t obj_id, uint16_t obj_inst_id, uint8_t *obj_data, uint16_t obj_size)
{
/* Reserve a free slot for our new object */
uint16_t free_slot_id;
struct slot_header slot_hdr;
if (logfs_reserve_free_slot(logfs, &free_slot_id, &slot_hdr, obj_id, obj_inst_id, obj_size) != 0) {
/* Failed to reserve a free slot */
return -1;
}
/* Compute slot address */
uintptr_t slot_addr = logfs_get_addr(logfs, logfs->active_arena_id, free_slot_id);
/* Write the data into the reserved slot, starting after the slot header */
uintptr_t slot_offset = sizeof(slot_hdr);
while (obj_size > 0) {
/* Individual writes must fit entirely within a single page buffer. */
uint16_t page_remaining = logfs->cfg->page_size - (slot_offset % logfs->cfg->page_size);
uint16_t write_size = MIN(obj_size, page_remaining);
if (logfs->driver->write_data(logfs->flash_id,
slot_addr + slot_offset,
obj_data,
write_size) != 0) {
/* Failed to write the object data to the slot */
return -2;
}
/* Update our accounting */
obj_data += write_size;
slot_offset += write_size;
obj_size -= write_size;
}
/* Mark this slot active in one atomic step */
slot_hdr.state = SLOT_STATE_ACTIVE;
if (logfs->driver->write_data(logfs->flash_id,
slot_addr,
(uint8_t *)&slot_hdr,
sizeof(slot_hdr)) != 0) {
/* Failed to mark the slot active */
return -4;
}
/* Object has been successfully written to the slot */
logfs->num_active_slots++;
return 0;
}
/**********************************
*
* Provide a PIOS_FLASHFS_* driver
*
*********************************/
#include "pios_flashfs.h" /* API for flash filesystem */
/**
* @brief Saves one object instance to the filesystem
* @param[in] fs_id The filesystem to use for this action
* @param[in] obj UAVObject ID of the object to save
* @param[in] obj_inst_id The instance number of the object being saved
* @param[in] obj_data Contents of the object being saved
* @param[in] obj_size Size of the object being saved
* @return 0 if success or error code
* @retval -1 if fs_id is not a valid filesystem instance
* @retval -2 if failed to start transaction
* @retval -3 if failure to delete any previous versions of the object
* @retval -4 if filesystem is entirely full and garbage collection won't help
* @retval -5 if garbage collection failed
* @retval -6 if filesystem is full even after garbage collection should have freed space
* @retval -7 if writing the new object to the filesystem failed
*/
int32_t PIOS_FLASHFS_ObjSave(uintptr_t fs_id, uint32_t obj_id, uint16_t obj_inst_id, uint8_t *obj_data, uint16_t obj_size)
{
int8_t rc;
struct logfs_state *logfs = (struct logfs_state *)fs_id;
if (!PIOS_FLASHFS_Logfs_validate(logfs)) {
rc = -1;
goto out_exit;
}
PIOS_Assert(obj_size <= (logfs->cfg->slot_size - sizeof(struct slot_header)));
if (logfs->driver->start_transaction(logfs->flash_id) != 0) {
rc = -2;
goto out_exit;
}
if (logfs_delete_object(logfs, obj_id, obj_inst_id) != 0) {
rc = -3;
goto out_end_trans;
}
/*
* All old versions of this object + instance have been invalidated.
* Write the new object.
*/
/* Check if the arena is entirely full. */
if (logfs_fs_is_full(logfs)) {
/* Note: Filesystem Full means we're full of *active* records so gc won't help at all. */
rc = -4;
goto out_end_trans;
}
/* Is garbage collection required? */
if (logfs_log_is_full(logfs)) {
/* Note: Log Full means the log is full but may contain obsolete slots so gc may free some space */
if (logfs_garbage_collect(logfs) != 0) {
rc = -5;
goto out_end_trans;
}
/* Check one more time just to be sure we actually free'd some space */
if (logfs_log_is_full(logfs)) {
/*
* Log is still full even after gc!
* NOTE: This should not happen since the filesystem wasn't full
* when we checked above so gc should have helped.
*/
PIOS_DEBUG_Assert(0);
rc = -6;
goto out_end_trans;
}
}
/* We have room for our new object. Append it to the log. */
if (logfs_append_to_log(logfs, obj_id, obj_inst_id, obj_data, obj_size) != 0) {
/* Error during append */
rc = -7;
goto out_end_trans;
}
/* Object successfully written to the log */
rc = 0;
out_end_trans:
logfs->driver->end_transaction(logfs->flash_id);
out_exit:
return rc;
}
/**
* @brief Load one object instance from the filesystem
* @param[in] fs_id The filesystem to use for this action
* @param[in] obj UAVObject ID of the object to load
* @param[in] obj_inst_id The instance of the object to load
* @param[in] obj_data Buffer to hold the contents of the loaded object
* @param[in] obj_size Size of the object to be loaded
* @return 0 if success or error code
* @retval -1 if fs_id is not a valid filesystem instance
* @retval -2 if failed to start transaction
* @retval -3 if object not found in filesystem
* @retval -4 if object size in filesystem does not exactly match buffer size
* @retval -5 if reading the object data from flash fails
*/
int32_t PIOS_FLASHFS_ObjLoad(uintptr_t fs_id, uint32_t obj_id, uint16_t obj_inst_id, uint8_t *obj_data, uint16_t obj_size)
{
int8_t rc;
struct logfs_state *logfs = (struct logfs_state *)fs_id;
if (!PIOS_FLASHFS_Logfs_validate(logfs)) {
rc = -1;
goto out_exit;
}
PIOS_Assert(obj_size <= (logfs->cfg->slot_size - sizeof(struct slot_header)));
if (logfs->driver->start_transaction(logfs->flash_id) != 0) {
rc = -2;
goto out_exit;
}
/* Find the object in the log */
uint16_t slot_id = 0;
struct slot_header slot_hdr;
if (logfs_object_find_next(logfs, &slot_hdr, &slot_id, obj_id, obj_inst_id) != 0) {
/* Object does not exist in fs */
rc = -3;
goto out_end_trans;
}
/* Sanity check what we've found */
if (slot_hdr.obj_size != obj_size) {
/* Object sizes don't match. Not safe to copy contents. */
rc = -4;
goto out_end_trans;
}
/* Read the contents of the object from the log */
if (obj_size > 0) {
uintptr_t slot_addr = logfs_get_addr(logfs, logfs->active_arena_id, slot_id);
if (logfs->driver->read_data(logfs->flash_id,
slot_addr + sizeof(slot_hdr),
(uint8_t *)obj_data,
obj_size) != 0) {
/* Failed to read object data from the log */
rc = -5;
goto out_end_trans;
}
}
/* Object successfully loaded */
rc = 0;
out_end_trans:
logfs->driver->end_transaction(logfs->flash_id);
out_exit:
return rc;
}
/**
* @brief Delete one instance of an object from the filesystem
* @param[in] fs_id The filesystem to use for this action
* @param[in] obj UAVObject ID of the object to delete
* @param[in] obj_inst_id The instance of the object to delete
* @return 0 if success or error code
* @retval -1 if fs_id is not a valid filesystem instance
* @retval -2 if failed to start transaction
* @retval -3 if failed to delete the object from the filesystem
*/
int32_t PIOS_FLASHFS_ObjDelete(uintptr_t fs_id, uint32_t obj_id, uint16_t obj_inst_id)
{
int8_t rc;
struct logfs_state *logfs = (struct logfs_state *)fs_id;
if (!PIOS_FLASHFS_Logfs_validate(logfs)) {
rc = -1;
goto out_exit;
}
if (logfs->driver->start_transaction(logfs->flash_id) != 0) {
rc = -2;
goto out_exit;
}
if (logfs_delete_object(logfs, obj_id, obj_inst_id) != 0) {
rc = -3;
goto out_end_trans;
}
/* Object successfully deleted from the log */
rc = 0;
out_end_trans:
logfs->driver->end_transaction(logfs->flash_id);
out_exit:
return rc;
}
/**
* @brief Erases all filesystem arenas and activate the first arena
* @param[in] fs_id The filesystem to use for this action
* @return 0 if success or error code
* @retval -1 if fs_id is not a valid filesystem instance
* @retval -2 if failed to start transaction
* @retval -3 if failed to erase all arenas
* @retval -4 if failed to activate arena 0
* @retval -5 if failed to mount arena 0
*/
int32_t PIOS_FLASHFS_Format(uintptr_t fs_id)
{
int32_t rc;
struct logfs_state *logfs = (struct logfs_state *)fs_id;
if (!PIOS_FLASHFS_Logfs_validate(logfs)) {
rc = -1;
goto out_exit;
}
if (logfs->mounted) {
logfs_unmount_log(logfs);
}
if (logfs->driver->start_transaction(logfs->flash_id) != 0) {
rc = -2;
goto out_exit;
}
if (logfs_erase_all_arenas(logfs) != 0) {
rc = -3;
goto out_end_trans;
}
/* Reinitialize arena 0 */
if (logfs_activate_arena(logfs, 0) != 0) {
rc = -4;
goto out_end_trans;
}
/* Mount arena 0 */
if (logfs_mount_log(logfs, 0) != 0) {
rc = -5;
goto out_end_trans;
}
/* Chip erased and log remounted successfully */
rc = 0;
out_end_trans:
logfs->driver->end_transaction(logfs->flash_id);
out_exit:
return rc;
}
/**
* @brief Returs stats for the filesystems
* @param[in] fs_id The filesystem to use for this action
* @return 0 if success or error code
* @retval -1 if fs_id is not a valid filesystem instance
*/
int32_t PIOS_FLASHFS_GetStats(uintptr_t fs_id, struct PIOS_FLASHFS_Stats *stats)
{
PIOS_Assert(stats);
struct logfs_state *logfs = (struct logfs_state *)fs_id;
if (!PIOS_FLASHFS_Logfs_validate(logfs)) {
return -1;
}
stats->num_active_slots = logfs->num_active_slots;
stats->num_free_slots = logfs->num_free_slots;
return 0;
}
#endif /* PIOS_INCLUDE_FLASH */
/**
* @}
* @}
*/