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Restructured the major interfaces of the filesystem

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This commit is contained in:
Christopher Haster 2017-03-25 16:20:31 -05:00
parent f566846223
commit 84a57642e5
8 changed files with 481 additions and 444 deletions
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82
emubd/lfs_emubd.c
View File

@ -17,7 +17,7 @@
// Block device emulated on existing filesystem
lfs_error_t lfs_emubd_create(lfs_emubd_t *emu, const char *path) {
int lfs_emubd_create(lfs_emubd_t *emu, const char *path) {
memset(&emu->info, 0, sizeof(emu->info));
memset(&emu->stats, 0, sizeof(emu->stats));
@ -42,7 +42,7 @@ lfs_error_t lfs_emubd_create(lfs_emubd_t *emu, const char *path) {
}
emu->info.read_size = lfs_cfg_getu(&cfg, "read_size", 0);
emu->info.write_size = lfs_cfg_getu(&cfg, "write_size", 0);
emu->info.prog_size = lfs_cfg_getu(&cfg, "prog_size", 0);
emu->info.erase_size = lfs_cfg_getu(&cfg, "erase_size", 0);
emu->info.total_size = lfs_cfg_getu(&cfg, "total_size", 0);
@ -55,23 +55,24 @@ void lfs_emubd_destroy(lfs_emubd_t *emu) {
free(emu->path);
}
lfs_error_t lfs_emubd_read(lfs_emubd_t *emu, uint8_t *buffer,
lfs_ino_t ino, lfs_off_t off, lfs_size_t size) {
int lfs_emubd_read(lfs_emubd_t *emu, lfs_block_t block,
lfs_off_t off, lfs_size_t size, void *buffer) {
uint8_t *data = buffer;
// Check if read is valid
if (!(off % emu->info.read_size == 0 &&
size % emu->info.read_size == 0 &&
((lfs_lsize_t)ino*emu->info.erase_size + off + size
((uint64_t)block*emu->info.erase_size + off + size
< emu->info.total_size))) {
return -EINVAL;
}
// Zero out buffer for debugging
memset(buffer, 0, size);
memset(data, 0, size);
// Iterate over blocks until enough data is read
while (size > 0) {
snprintf(emu->child, LFS_NAME_MAX, "%d", ino);
snprintf(emu->child, LFS_NAME_MAX, "%d", block);
size_t count = lfs_min(emu->info.erase_size - off, size);
FILE *f = fopen(emu->path, "rb");
@ -85,7 +86,7 @@ lfs_error_t lfs_emubd_read(lfs_emubd_t *emu, uint8_t *buffer,
return -errno;
}
size_t res = fread(buffer, 1, count, f);
size_t res = fread(data, 1, count, f);
if (res < count && !feof(f)) {
return -errno;
}
@ -97,8 +98,8 @@ lfs_error_t lfs_emubd_read(lfs_emubd_t *emu, uint8_t *buffer,
}
size -= count;
buffer += count;
ino += 1;
data += count;
block += 1;
off = 0;
}
@ -106,20 +107,21 @@ lfs_error_t lfs_emubd_read(lfs_emubd_t *emu, uint8_t *buffer,
return 0;
}
lfs_error_t lfs_emubd_write(lfs_emubd_t *emu, const uint8_t *buffer,
lfs_ino_t ino, lfs_off_t off, lfs_size_t size) {
int lfs_emubd_prog(lfs_emubd_t *emu, lfs_block_t block,
lfs_off_t off, lfs_size_t size, const void *buffer) {
const uint8_t *data = buffer;
// Check if write is valid
if (!(off % emu->info.write_size == 0 &&
size % emu->info.write_size == 0 &&
((lfs_lsize_t)ino*emu->info.erase_size + off + size
if (!(off % emu->info.prog_size == 0 &&
size % emu->info.prog_size == 0 &&
((uint64_t)block*emu->info.erase_size + off + size
< emu->info.total_size))) {
return -EINVAL;
}
// Iterate over blocks until enough data is read
while (size > 0) {
snprintf(emu->child, LFS_NAME_MAX, "%d", ino);
snprintf(emu->child, LFS_NAME_MAX, "%d", block);
size_t count = lfs_min(emu->info.erase_size - off, size);
FILE *f = fopen(emu->path, "r+b");
@ -135,7 +137,7 @@ lfs_error_t lfs_emubd_write(lfs_emubd_t *emu, const uint8_t *buffer,
return -errno;
}
size_t res = fwrite(buffer, 1, count, f);
size_t res = fwrite(data, 1, count, f);
if (res < count) {
return -errno;
}
@ -146,29 +148,29 @@ lfs_error_t lfs_emubd_write(lfs_emubd_t *emu, const uint8_t *buffer,
}
size -= count;
buffer += count;
ino += 1;
data += count;
block += 1;
off = 0;
}
emu->stats.write_count += 1;
emu->stats.prog_count += 1;
return 0;
}
lfs_error_t lfs_emubd_erase(lfs_emubd_t *emu,
lfs_ino_t ino, lfs_off_t off, lfs_size_t size) {
int lfs_emubd_erase(lfs_emubd_t *emu, lfs_block_t block,
lfs_off_t off, lfs_size_t size) {
// Check if erase is valid
if (!(off % emu->info.erase_size == 0 &&
size % emu->info.erase_size == 0 &&
((lfs_lsize_t)ino*emu->info.erase_size + off + size
((uint64_t)block*emu->info.erase_size + off + size
< emu->info.total_size))) {
return -EINVAL;
}
// Iterate and erase blocks
while (size > 0) {
snprintf(emu->child, LFS_NAME_MAX, "%d", ino);
snprintf(emu->child, LFS_NAME_MAX, "%d", block);
struct stat st;
int err = stat(emu->path, &st);
if (err && errno != ENOENT) {
@ -183,7 +185,7 @@ lfs_error_t lfs_emubd_erase(lfs_emubd_t *emu,
}
size -= emu->info.erase_size;
ino += 1;
block += 1;
off = 0;
}
@ -191,49 +193,49 @@ lfs_error_t lfs_emubd_erase(lfs_emubd_t *emu,
return 0;
}
lfs_error_t lfs_emubd_sync(lfs_emubd_t *emu) {
int lfs_emubd_sync(lfs_emubd_t *emu) {
// Always in sync
return 0;
}
lfs_error_t lfs_emubd_info(lfs_emubd_t *emu, struct lfs_bd_info *info) {
int lfs_emubd_info(lfs_emubd_t *emu, struct lfs_bd_info *info) {
*info = emu->info;
return 0;
}
lfs_error_t lfs_emubd_stats(lfs_emubd_t *emu, struct lfs_bd_stats *stats) {
int lfs_emubd_stats(lfs_emubd_t *emu, struct lfs_bd_stats *stats) {
*stats = emu->stats;
return 0;
}
// Wrappers for void*s
static lfs_error_t lfs_emubd_bd_read(void *bd, uint8_t *buffer,
lfs_ino_t ino, lfs_off_t off, lfs_size_t size) {
return lfs_emubd_read((lfs_emubd_t*)bd, buffer, ino, off, size);
static int lfs_emubd_bd_read(void *bd, lfs_block_t block,
lfs_off_t off, lfs_size_t size, void *buffer) {
return lfs_emubd_read((lfs_emubd_t*)bd, block, off, size, buffer);
}
static lfs_error_t lfs_emubd_bd_write(void *bd, const uint8_t *buffer,
lfs_ino_t ino, lfs_off_t off, lfs_size_t size) {
return lfs_emubd_write((lfs_emubd_t*)bd, buffer, ino, off, size);
static int lfs_emubd_bd_prog(void *bd, lfs_block_t block,
lfs_off_t off, lfs_size_t size, const void *buffer) {
return lfs_emubd_prog((lfs_emubd_t*)bd, block, off, size, buffer);
}
static lfs_error_t lfs_emubd_bd_erase(void *bd,
lfs_ino_t ino, lfs_off_t off, lfs_size_t size) {
return lfs_emubd_erase((lfs_emubd_t*)bd, ino, off, size);
static int lfs_emubd_bd_erase(void *bd, lfs_block_t block,
lfs_off_t off, lfs_size_t size) {
return lfs_emubd_erase((lfs_emubd_t*)bd, block, off, size);
}
static lfs_error_t lfs_emubd_bd_sync(void *bd) {
static int lfs_emubd_bd_sync(void *bd) {
return lfs_emubd_sync((lfs_emubd_t*)bd);
}
static lfs_error_t lfs_emubd_bd_info(void *bd, struct lfs_bd_info *info) {
static int lfs_emubd_bd_info(void *bd, struct lfs_bd_info *info) {
return lfs_emubd_info((lfs_emubd_t*)bd, info);
}
const struct lfs_bd_ops lfs_emubd_ops = {
.read = lfs_emubd_bd_read,
.write = lfs_emubd_bd_write,
.prog = lfs_emubd_bd_prog,
.erase = lfs_emubd_bd_erase,
.sync = lfs_emubd_bd_sync,
.info = lfs_emubd_bd_info,

27
emubd/lfs_emubd.h
View File

@ -8,14 +8,15 @@
#define LFS_EMUBD_H
#include "lfs_config.h"
#include "lfs_util.h"
#include "lfs_bd.h"
// Stats for debugging and optimization
struct lfs_bd_stats {
lfs_lword_t read_count;
lfs_lword_t write_count;
lfs_lword_t erase_count;
uint64_t read_count;
uint64_t prog_count;
uint64_t erase_count;
};
// The emu bd state
@ -28,40 +29,40 @@ typedef struct lfs_emubd {
// Create a block device using path for the directory to store blocks
lfs_error_t lfs_emubd_create(lfs_emubd_t *emu, const char *path);
int lfs_emubd_create(lfs_emubd_t *emu, const char *path);
// Clean up memory associated with emu block device
void lfs_emubd_destroy(lfs_emubd_t *emu);
// Read a block
lfs_error_t lfs_emubd_read(lfs_emubd_t *bd, uint8_t *buffer,
lfs_ino_t ino, lfs_off_t off, lfs_size_t size);
int lfs_emubd_read(lfs_emubd_t *bd, lfs_block_t block,
lfs_off_t off, lfs_size_t size, void *buffer);
// Program a block
//
// The block must have previously been erased.
lfs_error_t lfs_emubd_write(lfs_emubd_t *bd, const uint8_t *buffer,
lfs_ino_t ino, lfs_off_t off, lfs_size_t size);
int lfs_emubd_prog(lfs_emubd_t *bd, lfs_block_t block,
lfs_off_t off, lfs_size_t size, const void *buffer);
// Erase a block
//
// A block must be erased before being programmed. The
// state of an erased block is undefined.
lfs_error_t lfs_emubd_erase(lfs_emubd_t *bd,
lfs_ino_t ino, lfs_off_t off, lfs_size_t size);
int lfs_emubd_erase(lfs_emubd_t *bd, lfs_block_t block,
lfs_off_t off, lfs_size_t size);
// Sync the block device
lfs_error_t lfs_emubd_sync(lfs_emubd_t *bd);
int lfs_emubd_sync(lfs_emubd_t *bd);
// Get a description of the block device
//
// Any unknown information may be left unmodified
lfs_error_t lfs_emubd_info(lfs_emubd_t *bd, struct lfs_bd_info *info);
int lfs_emubd_info(lfs_emubd_t *bd, struct lfs_bd_info *info);
// Get stats of operations on the block device
//
// Used for debugging and optimizations
lfs_error_t lfs_emubd_stats(lfs_emubd_t *bd, struct lfs_bd_stats *stats);
int lfs_emubd_stats(lfs_emubd_t *bd, struct lfs_bd_stats *stats);
// Block device operations
extern const struct lfs_bd_ops lfs_emubd_ops;

557
lfs.c
View File

@ -5,62 +5,107 @@
* Distributed under the MIT license
*/
#include "lfs.h"
#include "lfs_util.h"
#include <string.h>
#include <stdbool.h>
static int lfs_diff(uint32_t a, uint32_t b) {
return (int)(unsigned)(a - b);
/// Block device operations ///
static int lfs_bd_info(lfs_t *lfs, struct lfs_bd_info *info) {
return lfs->bd_ops->info(lfs->bd, info);
}
static uint32_t lfs_crc(const uint8_t *data, lfs_size_t size, uint32_t crc) {
static const uint32_t rtable[16] = {
0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c,
};
for (lfs_size_t i = 0; i < size; i++) {
crc = (crc >> 4) ^ rtable[(crc ^ (data[i] >> 0)) & 0xf];
crc = (crc >> 4) ^ rtable[(crc ^ (data[i] >> 4)) & 0xf];
}
return crc;
static int lfs_bd_read(lfs_t *lfs, lfs_block_t block,
lfs_off_t off, lfs_size_t size, void *buffer) {
return lfs->bd_ops->read(lfs->bd, block, off, size, buffer);
}
static lfs_error_t lfs_bd_cmp(lfs_t *lfs,
lfs_ino_t ino, lfs_off_t off, lfs_size_t size, const void *d) {
const uint8_t *data = d;
static int lfs_bd_prog(lfs_t *lfs, lfs_block_t block,
lfs_off_t off, lfs_size_t size, const void *buffer) {
return lfs->bd_ops->prog(lfs->bd, block, off, size, buffer);
}
for (int i = 0; i < size; i++) {
static int lfs_bd_erase(lfs_t *lfs, lfs_block_t block,
lfs_off_t off, lfs_size_t size) {
return lfs->bd_ops->erase(lfs->bd, block, off, size);
}
static int lfs_bd_sync(lfs_t *lfs) {
return lfs->bd_ops->sync(lfs->bd);
}
static int lfs_bd_cmp(lfs_t *lfs, lfs_block_t block,
lfs_off_t off, lfs_size_t size, const void *buffer) {
const uint8_t *data = buffer;
while (off < size) {
uint8_t c;
int err = lfs->ops->read(lfs->bd, (void*)&c, ino, off + i, 1);
int err = lfs_bd_read(lfs, block, off, 1, &c);
if (err) {
return err;
}
if (c != data[i]) {
if (c != *data) {
return false;
}
data += 1;
off += 1;
}
return true;
}
static int lfs_bd_crc(lfs_t *lfs, lfs_block_t block,
lfs_off_t off, lfs_size_t size, uint32_t *crc) {
while (off < size) {
uint8_t c;
int err = lfs_bd_read(lfs, block, off, 1, &c);
if (err) {
return err;
}
*crc = lfs_crc(&c, 1, *crc);
off += 1;
}
return 0;
}
static lfs_error_t lfs_alloc(lfs_t *lfs, lfs_ino_t *ino);
/// Block allocator ///
static int lfs_alloc(lfs_t *lfs, lfs_block_t *block) {
if (lfs->free.begin != lfs->free.end) {
*block = lfs->free.begin;
lfs->free.begin += 1;
return 0;
}
// TODO find next stride of free blocks
// TODO verify no strides exist where begin > current begin
// note: begin = 0 is invalid (superblock)
return LFS_ERROR_NO_SPACE;
}
static int lfs_alloc_erased(lfs_t *lfs, lfs_block_t *block) {
int err = lfs_alloc(lfs, block);
if (err) {
return err;
}
return lfs_bd_erase(lfs, *block, 0, lfs->block_size);
}
/// Index list operations ///
// Next index offset
static lfs_off_t lfs_inext(lfs_t *lfs, lfs_off_t ioff) {
static lfs_off_t lfs_index_next(lfs_t *lfs, lfs_off_t ioff) {
ioff += 1;
lfs_size_t wcount = lfs->info.erase_size/4;
while (ioff % wcount == 0) {
ioff += lfs_min(lfs_ctz(ioff/wcount + 1), wcount-1) + 1;
while (ioff % lfs->words == 0) {
ioff += lfs_min(lfs_ctz(ioff/lfs->words + 1), lfs->words-1) + 1;
}
return ioff;
@ -68,28 +113,26 @@ static lfs_off_t lfs_inext(lfs_t *lfs, lfs_off_t ioff) {
static lfs_off_t lfs_toindex(lfs_t *lfs, lfs_off_t off) {
lfs_off_t i = 0;
while (off > 512) {
i = lfs_inext(lfs, i);
off -= 512;
while (off > lfs->block_size) {
i = lfs_index_next(lfs, i);
off -= lfs->block_size;
}
return i;
}
// Find index in index chain given its index offset
static lfs_error_t lfs_ifind_block(lfs_t *lfs, lfs_ino_t head,
lfs_size_t icount, lfs_off_t ioff, lfs_ino_t *block) {
lfs_size_t wcount = lfs->info.erase_size/4;
lfs_off_t iitarget = ioff / wcount;
lfs_off_t iicurrent = (icount-1) / wcount;
static int lfs_index_find(lfs_t *lfs, lfs_block_t head,
lfs_size_t icount, lfs_off_t ioff, lfs_block_t *block) {
lfs_off_t iitarget = ioff / lfs->words;
lfs_off_t iicurrent = (icount-1) / lfs->words;
while (iitarget != iicurrent) {
lfs_size_t skip = lfs_min(
lfs_min(lfs_ctz(iicurrent+1), wcount-1),
lfs_min(lfs_ctz(iicurrent+1), lfs->words-1),
lfs_npw2((iitarget ^ iicurrent)+1)-1);
lfs_error_t err = lfs->ops->read(lfs->bd, (void*)&head,
head, 4*skip, 4);
int err = lfs_bd_read(lfs, head, 4*skip, 4, &head);
if (err) {
return err;
}
@ -97,46 +140,34 @@ static lfs_error_t lfs_ifind_block(lfs_t *lfs, lfs_ino_t head,
iicurrent -= 1 << skip;
}
*block = head;
return 0;
}
static lfs_error_t lfs_ifind(lfs_t *lfs, lfs_ino_t head,
lfs_size_t icount, lfs_off_t ioff, lfs_ino_t *ino) {
lfs_size_t wcount = lfs->info.erase_size/4;
int err = lfs_ifind_block(lfs, head, icount, ioff, &head);
if (err) {
return err;
}
return lfs->ops->read(lfs->bd, (void*)ino, head, 4*(ioff % wcount), 4);
return lfs_bd_read(lfs, head, 4*(ioff % lfs->words), 4, block);
}
// Append index to index chain, updates head and icount
static lfs_error_t lfs_iappend(lfs_t *lfs, lfs_ino_t *headp,
lfs_size_t *icountp, lfs_ino_t ino) {
lfs_ino_t head = *headp;
static int lfs_index_append(lfs_t *lfs, lfs_block_t *headp,
lfs_size_t *icountp, lfs_block_t block) {
lfs_block_t head = *headp;
lfs_size_t ioff = *icountp - 1;
lfs_size_t wcount = lfs->info.erase_size/4;
ioff += 1;
while (ioff % wcount == 0) {
lfs_ino_t nhead;
lfs_error_t err = lfs_alloc(lfs, &nhead);
while (ioff % lfs->words == 0) {
lfs_block_t nhead;
int err = lfs_alloc_erased(lfs, &nhead);
if (err) {
return err;
}
lfs_off_t skips = lfs_min(lfs_ctz(ioff/wcount + 1), wcount-2) + 1;
lfs_off_t skips = lfs_min(
lfs_ctz(ioff/lfs->words + 1), lfs->words-2) + 1;
for (lfs_off_t i = 0; i < skips; i++) {
err = lfs->ops->write(lfs->bd, (void*)&head, nhead, 4*i, 4);
err = lfs_bd_prog(lfs, nhead, 4*i, 4, &head);
if (err) {
return err;
}
if (head && i != skips-1) {
err = lfs->ops->read(lfs->bd, (void*)&head, head, 4*i, 4);
err = lfs_bd_read(lfs, head, 4*i, 4, &head);
if (err) {
return err;
}
@ -147,8 +178,7 @@ static lfs_error_t lfs_iappend(lfs_t *lfs, lfs_ino_t *headp,
head = nhead;
}
lfs_error_t err = lfs->ops->write(lfs->bd, (void*)&ino,
head, 4*(ioff % wcount), 4);
int err = lfs_bd_prog(lfs, head, 4*(ioff % lfs->words), 4, &block);
if (err) {
return err;
}
@ -158,35 +188,13 @@ static lfs_error_t lfs_iappend(lfs_t *lfs, lfs_ino_t *headp,
return 0;
}
// Memory managment
static lfs_error_t lfs_alloc(lfs_t *lfs, lfs_ino_t *ino) {
if (lfs->free.d.begin != lfs->free.d.end) {
*ino = lfs->free.d.begin;
lfs->free.d.begin += 1;
return lfs->ops->erase(lfs->bd, *ino, 0, lfs->info.erase_size);
}
/// Metadata pair operations ///
// TODO find next stride of free blocks
// TODO verify no strides exist where begin > current begin
// note: begin = 0 is invalid (superblock)
return LFS_ERROR_NO_SPACE;
}
lfs_error_t lfs_check(lfs_t *lfs, lfs_ino_t block) {
uint32_t crc = 0xffffffff;
for (lfs_size_t i = 0; i < lfs->info.erase_size; i += 4) {
uint32_t data;
int err = lfs->ops->read(lfs->bd, (void*)&data, block, i, 4);
if (err) {
return err;
}
crc = lfs_crc((void*)&data, 4, crc);
}
return (crc != 0) ? LFS_ERROR_CORRUPT : LFS_ERROR_OK;
static inline void lfs_swap(lfs_block_t pair[2]) {
lfs_block_t t = pair[0];
pair[0] = pair[1];
pair[1] = t;
}
struct lfs_fetch_region {
@ -195,43 +203,44 @@ struct lfs_fetch_region {
void *data;
};
lfs_error_t lfs_pair_fetch(lfs_t *lfs, lfs_ino_t pair[2],
static int lfs_pair_fetch(lfs_t *lfs, lfs_block_t pair[2],
int count, const struct lfs_fetch_region *regions) {
int checked = 0;
int rev = 0;
for (int i = 0; i < 2; i++) {
uint32_t nrev;
int err = lfs->ops->read(lfs->bd, (void*)&nrev,
pair[0], 0, 4);
int err = lfs_bd_read(lfs, pair[1], 0, 4, &nrev);
if (err) {
return err;
}
// TODO diff these
if (checked > 0 && lfs_diff(nrev, rev) < 0) {
if (checked > 0 && lfs_scmp(nrev, rev) < 0) {
continue;
}
err = lfs_check(lfs, pair[0]);
if (err == LFS_ERROR_CORRUPT) {
lfs_swap(&pair[0], &pair[1]);
continue;
} else if (err) {
uint32_t crc = 0xffffffff;
err = lfs_bd_crc(lfs, pair[1], 0, lfs->block_size, &crc);
if (err) {
return err;
}
if (crc != 0) {
lfs_swap(pair);
}
checked += 1;
rev = nrev;
lfs_swap(&pair[0], &pair[1]);
lfs_swap(pair);
}
if (checked == 0) {
LFS_ERROR("Corrupted metadata pair at %d %d", pair[0], pair[1]);
return LFS_ERROR_CORRUPT;
}
for (int i = 0; i < count; i++) {
int err = lfs->ops->read(lfs->bd, regions[i].data,
pair[1], regions[i].off, regions[i].size);
int err = lfs_bd_read(lfs, pair[0],
regions[i].off, regions[i].size, regions[i].data);
if (err) {
return err;
}
@ -246,21 +255,20 @@ struct lfs_commit_region {
const void *data;
};
lfs_error_t lfs_pair_commit(lfs_t *lfs, lfs_ino_t pair[2],
static int lfs_pair_commit(lfs_t *lfs, lfs_block_t pair[2],
int count, const struct lfs_commit_region *regions) {
uint32_t crc = 0xffffffff;
int err = lfs->ops->erase(lfs->bd,
pair[0], 0, lfs->info.erase_size);
int err = lfs_bd_erase(lfs, pair[1], 0, lfs->block_size);
if (err) {
return err;
}
lfs_off_t off = 0;
while (off < lfs->info.erase_size - 4) {
while (off < lfs->block_size - 4) {
if (count > 0 && regions[0].off == off) {
crc = lfs_crc(regions[0].data, regions[0].size, crc);
int err = lfs->ops->write(lfs->bd, regions[0].data,
pair[0], off, regions[0].size);
int err = lfs_bd_prog(lfs, pair[1],
off, regions[0].size, regions[0].data);
if (err) {
return err;
}
@ -271,34 +279,39 @@ lfs_error_t lfs_pair_commit(lfs_t *lfs, lfs_ino_t pair[2],
} else {
// TODO faster strides?
uint8_t data;
int err = lfs->ops->read(lfs->bd, (void*)&data,
pair[1], off, sizeof(data));
int err = lfs_bd_read(lfs, pair[0], off, 1, &data);
if (err) {
return err;
}
crc = lfs_crc((void*)&data, sizeof(data), crc);
err = lfs->ops->write(lfs->bd, (void*)&data,
pair[0], off, sizeof(data));
crc = lfs_crc((void*)&data, 1, crc);
err = lfs_bd_prog(lfs, pair[1], off, 1, &data);
if (err) {
return err;
}
off += sizeof(data);
off += 1;
}
}
err = lfs->ops->write(lfs->bd, (void*)&crc,
pair[0], lfs->info.erase_size-4, 4);
err = lfs_bd_prog(lfs, pair[1], lfs->block_size-4, 4, &crc);
if (err) {
return err;
}
lfs_swap(&pair[0], &pair[1]);
err = lfs_bd_sync(lfs);
if (err) {
return err;
}
lfs_swap(pair);
return 0;
}
lfs_error_t lfs_dir_make(lfs_t *lfs, lfs_dir_t *dir, lfs_ino_t parent[2]) {
/// Directory operations ///
static int lfs_dir_create(lfs_t *lfs, lfs_dir_t *dir, lfs_block_t parent[2]) {
// Allocate pair of dir blocks
for (int i = 0; i < 2; i++) {
int err = lfs_alloc(lfs, &dir->pair[i]);
@ -309,89 +322,77 @@ lfs_error_t lfs_dir_make(lfs_t *lfs, lfs_dir_t *dir, lfs_ino_t parent[2]) {
// Rather than clobbering one of the blocks we just pretend
// the revision may be valid
int err = lfs->ops->read(lfs->bd, (void*)&dir->d.rev, dir->pair[1], 0, 4);
int err = lfs_bd_read(lfs, dir->pair[0], 0, 4, &dir->d.rev);
if (err) {
return err;
}
dir->d.rev += 1;
// Calculate total size
dir->d.size = sizeof(dir->d);
if (parent) {
dir->d.size += sizeof(struct lfs_disk_entry);
}
// Other defaults
dir->i = sizeof(struct lfs_disk_dir);
dir->d.size = sizeof(struct lfs_disk_dir);
dir->off = dir->d.size;
dir->d.tail[0] = 0;
dir->d.tail[1] = 0;
dir->d.free = lfs->free.d;
if (parent) {
// Create '..' entry
lfs_entry_t entry = {
.d.type = LFS_TYPE_DIR,
.d.len = sizeof(entry.d) + 2,
.d.u.dir[0] = parent[0],
.d.u.dir[1] = parent[1],
};
dir->d.size += entry.d.len;
dir->d.free = lfs->free;
// Write out to memory
return lfs_pair_commit(lfs, dir->pair,
3, (struct lfs_commit_region[3]){
1 + (parent ? 2 : 0), (struct lfs_commit_region[]){
{0, sizeof(dir->d), &dir->d},
{sizeof(dir->d), sizeof(entry.d), &entry.d},
{sizeof(dir->d)+sizeof(entry.d), 2, ".."},
{sizeof(dir->d), sizeof(struct lfs_disk_entry),
&(struct lfs_disk_entry){
.type = LFS_TYPE_DIR,
.len = 12+2,
.u.dir[0] = parent ? parent[0] : 0,
.u.dir[1] = parent ? parent[1] : 0,
}},
{sizeof(dir->d)+sizeof(struct lfs_disk_entry), 2, ".."},
});
} else {
return lfs_pair_commit(lfs, dir->pair,
1, (struct lfs_commit_region[1]){
{0, sizeof(dir->d), &dir->d},
});
}
}
lfs_error_t lfs_dir_fetch(lfs_t *lfs, lfs_dir_t *dir, lfs_ino_t pair[2]) {
static int lfs_dir_fetch(lfs_t *lfs, lfs_dir_t *dir, lfs_block_t pair[2]) {
dir->pair[0] = pair[0];
dir->pair[1] = pair[1];
dir->i = sizeof(dir->d);
dir->off = sizeof(dir->d);
int err = lfs_pair_fetch(lfs, dir->pair,
return lfs_pair_fetch(lfs, dir->pair,
1, (struct lfs_fetch_region[1]) {
{0, sizeof(dir->d), &dir->d}
});
if (err == LFS_ERROR_CORRUPT) {
LFS_ERROR("Corrupted dir at %d %d", pair[0], pair[1]);
}
return err;
}
lfs_error_t lfs_dir_next(lfs_t *lfs, lfs_dir_t *dir, lfs_entry_t *entry) {
static int lfs_dir_next(lfs_t *lfs, lfs_dir_t *dir, lfs_entry_t *entry) {
while (true) {
// TODO iterate down list
entry->dir[0] = dir->pair[0];
entry->dir[1] = dir->pair[1];
entry->off = dir->i;
entry->off = dir->off;
if (dir->d.size - dir->i < sizeof(entry->d)) {
if (dir->d.size - dir->off < sizeof(entry->d)) {
return LFS_ERROR_NO_ENTRY;
}
int err = lfs->ops->read(lfs->bd, (void*)&entry->d,
dir->pair[1], dir->i, sizeof(entry->d));
int err = lfs_bd_read(lfs, dir->pair[0], dir->off,
sizeof(entry->d), &entry->d);
if (err) {
return err;
}
dir->i += entry->d.len;
dir->off += entry->d.len;
// Skip any unknown entries
if (entry->d.type == 1 || entry->d.type == 2) {
if ((entry->d.type & 0xf) == 1 || (entry->d.type & 0xf) == 2) {
return 0;
}
}
}
lfs_error_t lfs_dir_find(lfs_t *lfs, lfs_dir_t *dir,
static int lfs_dir_find(lfs_t *lfs, lfs_dir_t *dir,
const char *path, lfs_entry_t *entry) {
// TODO follow directories
lfs_size_t pathlen = strcspn(path, "/");
@ -405,7 +406,7 @@ lfs_error_t lfs_dir_find(lfs_t *lfs, lfs_dir_t *dir,
continue;
}
int ret = lfs_bd_cmp(lfs, entry->dir[1],
int ret = lfs_bd_cmp(lfs, entry->dir[0],
entry->off + sizeof(entry->d), pathlen, path);
if (ret < 0) {
return ret;
@ -418,22 +419,60 @@ lfs_error_t lfs_dir_find(lfs_t *lfs, lfs_dir_t *dir,
}
}
lfs_error_t lfs_dir_alloc(lfs_t *lfs, lfs_dir_t *dir,
const char *path, lfs_entry_t *entry, uint16_t len) {
static int lfs_dir_append(lfs_t *lfs, lfs_dir_t *dir,
const char *path, lfs_entry_t *entry) {
int err = lfs_dir_find(lfs, dir, path, entry);
if (err != LFS_ERROR_NO_ENTRY) {
return err ? err : LFS_ERROR_EXISTS;
}
// Check if we fit
if (dir->d.size + len > lfs->info.erase_size - 4) {
if (dir->d.size + strlen(path) > lfs->block_size - 4) {
return -1; // TODO make fit
}
return 0;
}
lfs_error_t lfs_dir_open(lfs_t *lfs, lfs_dir_t *dir, const char *path) {
int lfs_mkdir(lfs_t *lfs, const char *path) {
// Allocate entry for directory
lfs_dir_t cwd;
int err = lfs_dir_fetch(lfs, &cwd, lfs->cwd);
if (err) {
return err;
}
lfs_entry_t entry;
err = lfs_dir_append(lfs, &cwd, path, &entry);
if (err) {
return err;
}
// Build up new directory
lfs_dir_t dir;
err = lfs_dir_create(lfs, &dir, cwd.pair);
if (err) {
return err;
}
entry.d.type = LFS_TYPE_DIR;
entry.d.len = sizeof(entry.d) + strlen(path);
entry.d.u.dir[0] = dir.pair[0];
entry.d.u.dir[1] = dir.pair[1];
cwd.d.rev += 1;
cwd.d.size += entry.d.len;
cwd.d.free = lfs->free;
return lfs_pair_commit(lfs, entry.dir,
3, (struct lfs_commit_region[3]) {
{0, sizeof(cwd.d), &cwd.d},
{entry.off, sizeof(entry.d), &entry.d},
{entry.off+sizeof(entry.d), entry.d.len - sizeof(entry.d), path}
});
}
int lfs_dir_open(lfs_t *lfs, lfs_dir_t *dir, const char *path) {
int err = lfs_dir_fetch(lfs, dir, lfs->cwd);
if (err) {
return err;
@ -450,51 +489,15 @@ lfs_error_t lfs_dir_open(lfs_t *lfs, lfs_dir_t *dir, const char *path) {
return lfs_dir_fetch(lfs, dir, entry.d.u.dir);
}
lfs_error_t lfs_dir_close(lfs_t *lfs, lfs_dir_t *dir) {
int lfs_dir_close(lfs_t *lfs, lfs_dir_t *dir) {
// Do nothing, dir is always synchronized
return 0;
}
lfs_error_t lfs_mkdir(lfs_t *lfs, const char *path) {
// Allocate entry for directory
lfs_dir_t cwd;
int err = lfs_dir_fetch(lfs, &cwd, lfs->cwd);
if (err) {
return err;
}
lfs_entry_t entry;
err = lfs_dir_alloc(lfs, &cwd, path,
&entry, sizeof(entry.d)+strlen(path));
if (err) {
return err;
}
/// File operations ///
// Build up new directory
lfs_dir_t dir;
err = lfs_dir_make(lfs, &dir, cwd.pair); // TODO correct parent?
if (err) {
return err;
}
entry.d.type = 2;
entry.d.len = sizeof(entry.d) + strlen(path);
entry.d.u.dir[0] = dir.pair[0];
entry.d.u.dir[1] = dir.pair[1];
cwd.d.rev += 1;
cwd.d.size += entry.d.len;
cwd.d.free = lfs->free.d;
return lfs_pair_commit(lfs, entry.dir,
3, (struct lfs_commit_region[3]) {
{0, sizeof(cwd.d), &cwd.d},
{entry.off, sizeof(entry.d), &entry.d},
{entry.off+sizeof(entry.d), entry.d.len - sizeof(entry.d), path}
});
}
lfs_error_t lfs_file_open(lfs_t *lfs, lfs_file_t *file,
int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
const char *path, int flags) {
// Allocate entry for file if it doesn't exist
// TODO check open files
@ -505,8 +508,7 @@ lfs_error_t lfs_file_open(lfs_t *lfs, lfs_file_t *file,
}
if (flags & LFS_O_CREAT) {
err = lfs_dir_alloc(lfs, &cwd, path,
&file->entry, sizeof(file->entry.d)+strlen(path));
err = lfs_dir_append(lfs, &cwd, path, &file->entry);
if (err && err != LFS_ERROR_EXISTS) {
return err;
}
@ -534,15 +536,17 @@ lfs_error_t lfs_file_open(lfs_t *lfs, lfs_file_t *file,
cwd.d.rev += 1;
cwd.d.size += file->entry.d.len;
cwd.d.free = lfs->free.d;
cwd.d.free = lfs->free;
return lfs_pair_commit(lfs, file->entry.dir,
3, (struct lfs_commit_region[3]) {
{0, sizeof(cwd.d), &cwd.d},
{file->entry.off, sizeof(file->entry.d),
{file->entry.off,
sizeof(file->entry.d),
&file->entry.d},
{file->entry.off+sizeof(file->entry.d),
file->entry.d.len-sizeof(file->entry.d), path}
file->entry.d.len-sizeof(file->entry.d),
path}
});
} else {
file->head = file->entry.d.u.file.head;
@ -554,10 +558,10 @@ lfs_error_t lfs_file_open(lfs_t *lfs, lfs_file_t *file,
// TODO do this lazily in write?
// TODO cow the head i/d block
if (file->size < lfs->info.erase_size) {
if (file->size < lfs->block_size) {
file->wblock = file->head;
} else {
int err = lfs_ifind(lfs, file->head, file->windex,
int err = lfs_index_find(lfs, file->head, file->windex,
file->windex, &file->wblock);
if (err) {
return err;
@ -568,7 +572,7 @@ lfs_error_t lfs_file_open(lfs_t *lfs, lfs_file_t *file,
}
}
lfs_error_t lfs_file_close(lfs_t *lfs, lfs_file_t *file) {
int lfs_file_close(lfs_t *lfs, lfs_file_t *file) {
// Store file
lfs_dir_t cwd;
int err = lfs_dir_fetch(lfs, &cwd, file->entry.dir);
@ -580,7 +584,7 @@ lfs_error_t lfs_file_close(lfs_t *lfs, lfs_file_t *file) {
file->entry.d.u.file.size = file->size;
cwd.d.rev += 1;
cwd.d.free = lfs->free.d;
cwd.d.free = lfs->free;
return lfs_pair_commit(lfs, file->entry.dir,
3, (struct lfs_commit_region[3]) {
@ -595,10 +599,10 @@ lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
lfs_size_t nsize = size;
while (nsize > 0) {
lfs_off_t woff = file->size % lfs->info.erase_size;
lfs_off_t woff = file->size % lfs->block_size;
if (file->size == 0) {
int err = lfs_alloc(lfs, &file->wblock);
int err = lfs_alloc_erased(lfs, &file->wblock);
if (err) {
return err;
}
@ -606,21 +610,20 @@ lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
file->head = file->wblock;
file->windex = 0;
} else if (woff == 0) {
// TODO check that 2 blocks are available
// TODO check for available blocks for backing up scratch files?
int err = lfs_alloc(lfs, &file->wblock);
int err = lfs_alloc_erased(lfs, &file->wblock);
if (err) {
return err;
}
err = lfs_iappend(lfs, &file->head, &file->windex, file->wblock);
err = lfs_index_append(lfs, &file->head,
&file->windex, file->wblock);
if (err) {
return err;
}
}
lfs_size_t diff = lfs_min(nsize, lfs->info.erase_size - woff);
int err = lfs->ops->write(lfs->bd, data, file->wblock, woff, diff);
lfs_size_t diff = lfs_min(nsize, lfs->block_size - woff);
int err = lfs_bd_prog(lfs, file->wblock, woff, diff, data);
if (err) {
return err;
}
@ -639,25 +642,25 @@ lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
lfs_size_t nsize = size;
while (nsize > 0 && file->roff < file->size) {
lfs_off_t roff = file->roff % lfs->info.erase_size;
lfs_off_t roff = file->roff % lfs->block_size;
// TODO cache index blocks
if (file->size < lfs->info.erase_size) {
if (file->size < lfs->block_size) {
file->rblock = file->head;
} else if (roff == 0) {
int err = lfs_ifind(lfs, file->head, file->windex,
int err = lfs_index_find(lfs, file->head, file->windex,
file->rindex, &file->rblock);
if (err) {
return err;
}
file->rindex = lfs_inext(lfs, file->rindex);
file->rindex = lfs_index_next(lfs, file->rindex);
}
lfs_size_t diff = lfs_min(
lfs_min(nsize, file->size-file->roff),
lfs->info.erase_size - roff);
int err = lfs->ops->read(lfs->bd, data, file->rblock, roff, diff);
lfs->block_size - roff);
int err = lfs_bd_read(lfs, file->rblock, roff, diff, data);
if (err) {
return err;
}
@ -671,112 +674,106 @@ lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
}
// Little filesystem operations
lfs_error_t lfs_create(lfs_t *lfs, lfs_bd_t *bd, const struct lfs_bd_ops *ops) {
/// Generic filesystem operations ///
int lfs_format(lfs_t *lfs, lfs_bd_t *bd, const struct lfs_bd_ops *bd_ops) {
lfs->bd = bd;
lfs->ops = ops;
lfs->bd_ops = bd_ops;
lfs_error_t err = lfs->ops->info(lfs->bd, &lfs->info);
if (err) {
return err;
}
return 0;
}
lfs_error_t lfs_format(lfs_t *lfs) {
struct lfs_bd_info info;
lfs_error_t err = lfs->ops->info(lfs->bd, &info);
int err = lfs_bd_info(lfs, &info);
if (err) {
return err;
}
err = lfs->ops->erase(lfs->bd, 0, 0, 3*info.erase_size);
if (err) {
return err;
}
// TODO make sure that erase clobbered blocks
{
lfs_size_t block_count = lfs->info.total_size / lfs->info.erase_size;
lfs->read_size = info.read_size;
lfs->prog_size = info.prog_size;
lfs->block_size = info.erase_size;
lfs->block_count = info.total_size / info.erase_size;
lfs->words = info.erase_size / sizeof(uint32_t);
// Create free list
lfs->free = (lfs_free_t){
.d.begin = 2,
.d.end = block_count,
};
}
lfs->free.begin = 2;
lfs->free.end = lfs->block_count;
{
// Write root directory
lfs_dir_t root;
int err = lfs_dir_make(lfs, &root, 0);
err = lfs_dir_create(lfs, &root, 0);
if (err) {
return err;
}
lfs->cwd[0] = root.pair[0];
lfs->cwd[1] = root.pair[1];
}
{
// Write superblocks
lfs_superblock_t superblock = {
.pair = {0, 1},
.d.rev = 1,
.d.size = sizeof(struct lfs_disk_superblock),
.d.size = sizeof(superblock),
.d.root = {lfs->cwd[0], lfs->cwd[1]},
.d.magic = {"littlefs"},
.d.block_size = info.erase_size,
.d.block_count = info.total_size / info.erase_size,
.d.block_size = lfs->block_size,
.d.block_count = lfs->block_count,
};
for (int i = 0; i < 2; i++) {
lfs_ino_t block = superblock.pair[0];
int err = lfs_pair_commit(lfs, superblock.pair,
1, (struct lfs_commit_region[1]){
1, (struct lfs_commit_region[]){
{0, sizeof(superblock.d), &superblock.d}
});
err = lfs_check(lfs, block);
if (err) {
LFS_ERROR("Failed to write superblock at %d", block);
LFS_ERROR("Failed to write superblock at %d", superblock.pair[1]);
return err;
}
uint32_t crc = 0xffffffff;
err = lfs_bd_crc(lfs, superblock.pair[0], 0, lfs->block_size, &crc);
if (err || crc != 0) {
LFS_ERROR("Failed to write superblock at %d", superblock.pair[0]);
return err ? err : LFS_ERROR_CORRUPT;
}
}
return 0;
}
lfs_error_t lfs_mount(lfs_t *lfs) {
int lfs_mount(lfs_t *lfs, lfs_bd_t *bd, const struct lfs_bd_ops *bd_ops) {
lfs->bd = bd;
lfs->bd_ops = bd_ops;
struct lfs_bd_info info;
lfs_error_t err = lfs->ops->info(lfs->bd, &info);
int err = lfs_bd_info(lfs, &info);
if (err) {
return err;
}
lfs_superblock_t superblock;
err = lfs_pair_fetch(lfs,
(lfs_ino_t[2]){0, 1},
1, (struct lfs_fetch_region[1]){
lfs->read_size = info.read_size;
lfs->prog_size = info.prog_size;
lfs->block_size = info.erase_size;
lfs->block_count = info.total_size / info.erase_size;
lfs->words = info.erase_size / sizeof(uint32_t);
lfs_superblock_t superblock = {
.pair = {0, 1},
};
err = lfs_pair_fetch(lfs, superblock.pair,
1, (struct lfs_fetch_region[]){
{0, sizeof(superblock.d), &superblock.d}
});
if ((err == LFS_ERROR_CORRUPT ||
memcmp(superblock.d.magic, "littlefs", 8) != 0)) {
LFS_ERROR("Invalid superblock at %d %d\n", 0, 1);
LFS_ERROR("Invalid superblock at %d %d\n",
superblock.pair[0], superblock.pair[1]);
return LFS_ERROR_CORRUPT;
}
printf("superblock %d %d\n",
superblock.d.block_size,
superblock.d.block_count);
lfs->cwd[0] = superblock.d.root[0];
lfs->cwd[1] = superblock.d.root[1];
return err;
}
int lfs_unmount(lfs_t *lfs) {
// No nothing for now
return 0;
}

87
lfs.h
View File

@ -38,63 +38,61 @@ enum lfs_open_flags {
LFS_O_SYNC = 0x1000,
};
typedef struct lfs_free {
lfs_disk_struct lfs_disk_free {
lfs_word_t begin;
lfs_word_t end;
} d;
} lfs_free_t;
typedef struct lfs_dir {
lfs_ino_t pair[2];
lfs_off_t i;
lfs_disk_struct lfs_disk_dir {
lfs_word_t rev;
lfs_size_t size;
lfs_ino_t tail[2];
struct lfs_disk_free free;
} d;
} lfs_dir_t;
typedef struct lfs_entry {
lfs_ino_t dir[2];
lfs_block_t dir[2];
lfs_off_t off;
lfs_disk_struct lfs_disk_entry {
struct lfs_disk_entry {
uint16_t type;
uint16_t len;
union {
lfs_disk_struct {
lfs_ino_t head;
struct {
lfs_block_t head;
lfs_size_t size;
} file;
lfs_ino_t dir[2];
lfs_block_t dir[2];
} u;
} d;
} lfs_entry_t;
typedef struct lfs_file {
lfs_ino_t head;
lfs_block_t head;
lfs_size_t size;
lfs_ino_t wblock;
lfs_word_t windex;
lfs_block_t wblock;
uint32_t windex;
lfs_ino_t rblock;
lfs_word_t rindex;
lfs_block_t rblock;
uint32_t rindex;
lfs_off_t roff;
struct lfs_entry entry;
} lfs_file_t;
typedef struct lfs_dir {
lfs_block_t pair[2];
lfs_off_t off;
struct lfs_disk_dir {
uint32_t rev;
lfs_size_t size;
lfs_block_t tail[2];
struct lfs_disk_free {
uint32_t begin;
uint32_t end;
} free;
} d;
} lfs_dir_t;
typedef struct lfs_superblock {
lfs_ino_t pair[2];
lfs_disk_struct lfs_disk_superblock {
lfs_word_t rev;
lfs_block_t pair[2];
struct lfs_disk_superblock {
uint32_t rev;
uint32_t size;
lfs_ino_t root[2];
lfs_block_t root[2];
char magic[8];
uint32_t block_size;
uint32_t block_count;
@ -104,23 +102,28 @@ typedef struct lfs_superblock {
// Little filesystem type
typedef struct lfs {
lfs_bd_t *bd;
const struct lfs_bd_ops *ops;
const struct lfs_bd_ops *bd_ops;
lfs_ino_t cwd[2];
lfs_free_t free;
struct lfs_bd_info info;
lfs_block_t cwd[2];
struct lfs_disk_free free;
lfs_size_t read_size; // size of read
lfs_size_t prog_size; // size of program
lfs_size_t block_size; // size of erase (block size)
lfs_size_t block_count; // number of erasable blocks
lfs_size_t words; // number of 32-bit words that can fit in a block
} lfs_t;
// Functions
lfs_error_t lfs_create(lfs_t *lfs, lfs_bd_t *bd, const struct lfs_bd_ops *bd_ops);
lfs_error_t lfs_format(lfs_t *lfs);
lfs_error_t lfs_mount(lfs_t *lfs);
int lfs_format(lfs_t *lfs, lfs_bd_t *bd, const struct lfs_bd_ops *bd_ops);
int lfs_mount(lfs_t *lfs, lfs_bd_t *bd, const struct lfs_bd_ops *bd_ops);
int lfs_unmount(lfs_t *lfs);
lfs_error_t lfs_mkdir(lfs_t *lfs, const char *path);
int lfs_mkdir(lfs_t *lfs, const char *path);
lfs_error_t lfs_file_open(lfs_t *lfs, lfs_file_t *file,
int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
const char *path, int flags);
lfs_error_t lfs_file_close(lfs_t *lfs, lfs_file_t *file);
int lfs_file_close(lfs_t *lfs, lfs_file_t *file);
lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
const void *buffer, lfs_size_t size);
lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,

20
lfs_bd.h
View File

@ -16,10 +16,10 @@ typedef void lfs_bd_t;
// Description of block devices
struct lfs_bd_info {
lfs_size_t read_size; // Size of readable block
lfs_size_t write_size; // Size of programmable block
lfs_size_t prog_size; // Size of programmable block
lfs_size_t erase_size; // Size of erase block
lfs_lsize_t total_size; // Total size of the device
uint64_t total_size; // Total size of the device
};
// Block device operations
@ -30,29 +30,29 @@ struct lfs_bd_info {
// block device
struct lfs_bd_ops {
// Read a block
lfs_error_t (*read)(lfs_bd_t *bd, uint8_t *buffer,
lfs_ino_t ino, lfs_off_t off, lfs_size_t size);
int (*read)(lfs_bd_t *bd, lfs_block_t block,
lfs_off_t off, lfs_size_t size, void *buffer);
// Program a block
//
// The block must have previously been erased.
lfs_error_t (*write)(lfs_bd_t *bd, const uint8_t *buffer,
lfs_ino_t ino, lfs_off_t off, lfs_size_t size);
int (*prog)(lfs_bd_t *bd, lfs_block_t block,
lfs_off_t off, lfs_size_t size, const void *buffer);
// Erase a block
//
// A block must be erased before being programmed. The
// state of an erased block is undefined.
lfs_error_t (*erase)(lfs_bd_t *bd,
lfs_ino_t ino, lfs_off_t off, lfs_size_t size);
int (*erase)(lfs_bd_t *bd, lfs_block_t block,
lfs_off_t off, lfs_size_t size);
// Sync the block device
lfs_error_t (*sync)(lfs_bd_t *bd);
int (*sync)(lfs_bd_t *bd);
// Get a description of the block device
//
// Any unknown information may be left as zero
lfs_error_t (*info)(lfs_bd_t *bd, struct lfs_bd_info *info);
int (*info)(lfs_bd_t *bd, struct lfs_bd_info *info);
};

39
lfs_config.h
View File

@ -10,48 +10,17 @@
#include <stdint.h>
// Type definitions
typedef uint64_t lfs_lword_t;
typedef uint32_t lfs_word_t;
typedef uint16_t lfs_hword_t;
typedef uint32_t lfs_size_t;
typedef uint32_t lfs_off_t;
typedef lfs_word_t lfs_size_t;
typedef int32_t lfs_ssize_t;
typedef lfs_word_t lfs_off_t;
typedef int lfs_error_t;
typedef int32_t lfs_soff_t;
typedef lfs_lword_t lfs_lsize_t;
typedef lfs_word_t lfs_ino_t;
typedef lfs_hword_t lfs_ioff_t;
typedef uint32_t lfs_block_t;
// Maximum length of file name
#define LFS_NAME_MAX 255
// Builtin functions
static inline lfs_word_t lfs_max(lfs_word_t a, lfs_word_t b) {
return (a > b) ? a : b;
}
static inline lfs_word_t lfs_min(lfs_word_t a, lfs_word_t b) {
return (a < b) ? a : b;
}
static inline lfs_word_t lfs_ctz(lfs_word_t a) {
return __builtin_ctz(a);
}
static inline lfs_word_t lfs_npw2(lfs_word_t a) {
return 32 - __builtin_clz(a-1);
}
static inline void lfs_swap(lfs_word_t *a, lfs_word_t *b) {
lfs_word_t temp = *a;
*a = *b;
*b = temp;
}
// Attributes
#define lfs_disk_struct struct __attribute__((packed))
// Logging operations
#include <stdio.h>
#define LFS_ERROR(fmt, ...) printf("Error: " fmt "\n", __VA_ARGS__)

27
lfs_util.c Normal file
View File

@ -0,0 +1,27 @@
/*
* lfs util functions
*
* Copyright (c) 2017 Christopher Haster
* Distributed under the MIT license
*/
#include "lfs_util.h"
uint32_t lfs_crc(const void *buffer, lfs_size_t size, uint32_t crc) {
static const uint32_t rtable[16] = {
0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c,
};
const uint8_t *data = buffer;
for (lfs_size_t i = 0; i < size; i++) {
crc = (crc >> 4) ^ rtable[(crc ^ (data[i] >> 0)) & 0xf];
crc = (crc >> 4) ^ rtable[(crc ^ (data[i] >> 4)) & 0xf];
}
return crc;
}

38
lfs_util.h Normal file
View File

@ -0,0 +1,38 @@
/*
* lfs utility functions
*
* Copyright (c) 2017 Christopher Haster
* Distributed under the MIT license
*/
#ifndef LFS_UTIL_H
#define LFS_UTIL_H
#include "lfs_config.h"
// Builtin functions
static inline uint32_t lfs_max(uint32_t a, uint32_t b) {
return (a > b) ? a : b;
}
static inline uint32_t lfs_min(uint32_t a, uint32_t b) {
return (a < b) ? a : b;
}
static inline uint32_t lfs_ctz(uint32_t a) {
return __builtin_ctz(a);
}
static inline uint32_t lfs_npw2(uint32_t a) {
return 32 - __builtin_clz(a-1);
}
static inline int lfs_scmp(uint32_t a, uint32_t b) {
return (int)(unsigned)(a - b);
}
uint32_t lfs_crc(const void *buffer, lfs_size_t size, uint32_t crc);
#endif