Add version info for software library and on-disk structures

An annoying part of filesystems is that the software library can change
independently of the on-disk structures. For this reason versioning is
very important, and must be handled separately for the software and
on-disk parts.

In this patch, littlefs provides two version numbers at compile time,
with major and minor parts, in the form of 6 macros.

LFS_VERSION        // Library version, uint32_t encoded
LFS_VERSION_MAJOR  // Major - Backwards incompatible changes
LFS_VERSION_MINOR  // Minor - Feature additions

LFS_DISK_VERSION        // On-disk version, uint32_t encoded
LFS_DISK_VERSION_MAJOR  // Major - Backwards incompatible changes
LFS_DISK_VERSION_MINOR  // Minor - Feature additions

Note that littlefs will error if it finds a major version number that
is different, or a minor version number that has regressed.
This commit is contained in:
Christopher Haster
2018-01-26 14:26:25 -06:00
parent 997c2e594e
commit 035552a858
2 changed files with 23 additions and 5 deletions

11
lfs.c
View File

@@ -2067,7 +2067,7 @@ int lfs_format(lfs_t *lfs, const struct lfs_config *cfg) {
.d.type = LFS_TYPE_SUPERBLOCK,
.d.elen = sizeof(superblock.d) - sizeof(superblock.d.magic) - 4,
.d.nlen = sizeof(superblock.d.magic),
.d.version = 0x00010001,
.d.version = LFS_DISK_VERSION,
.d.magic = {"littlefs"},
.d.block_size = lfs->cfg->block_size,
.d.block_count = lfs->cfg->block_count,
@@ -2140,10 +2140,11 @@ int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
return LFS_ERR_CORRUPT;
}
if (superblock.d.version > (0x00010001 | 0x0000ffff)) {
LFS_ERROR("Invalid version %d.%d",
0xffff & (superblock.d.version >> 16),
0xffff & (superblock.d.version >> 0));
uint16_t major_version = (0xffff & (superblock.d.version >> 16));
uint16_t minor_version = (0xffff & (superblock.d.version >> 0));
if ((major_version != LFS_DISK_VERSION_MAJOR ||
minor_version > LFS_DISK_VERSION_MINOR)) {
LFS_ERROR("Invalid version %d.%d", major_version, minor_version);
return LFS_ERR_INVAL;
}

17
lfs.h
View File

@@ -22,6 +22,23 @@
#include <stdbool.h>
/// Version info ///
// Software library version
// Major (top-nibble), incremented on backwards incompatible changes
// Minor (bottom-nibble), incremented on feature additions
#define LFS_VERSION 0x00010002
#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 0x00010001
#define LFS_DISK_VERSION_MAJOR (0xffff & (LFS_DISK_VERSION >> 16))
#define LFS_DISK_VERSION_MINOR (0xffff & (LFS_DISK_VERSION >> 0))
/// Definitions ///
// Type definitions