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WIP simplified and aligned globals

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by storing deorphaned in the globals tag itself
This commit is contained in:
Christopher Haster
2018-08-03 19:01:27 -05:00
parent 597249eea0
commit e7c4465bf5
2 changed files with 69 additions and 105 deletions
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161
lfs.c
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@@ -265,7 +265,6 @@ static int32_t lfs_fs_parent(lfs_t *lfs, const lfs_block_t dir[2],
lfs_mdir_t *parent);
static int lfs_fs_relocate(lfs_t *lfs,
const lfs_block_t oldpair[2], lfs_block_t newpair[2]);
static int lfs_fs_scan(lfs_t *lfs);
static int lfs_fs_forceconsistency(lfs_t *lfs);
@@ -410,14 +409,14 @@ static inline lfs_size_t lfs_tagsize(uint32_t tag) {
// operations on set of globals
static inline void lfs_globalxor(lfs_global_t *a, const lfs_global_t *b) {
for (int i = 0; i < sizeof(lfs_global_t)/2; i++) {
a->u16[i] ^= b->u16[i];
for (int i = 0; i < sizeof(lfs_global_t)/4; i++) {
a->u32[i] ^= b->u32[i];
}
}
static inline bool lfs_globaliszero(const lfs_global_t *a) {
for (int i = 0; i < sizeof(lfs_global_t)/2; i++) {
if (a->u16[i] != 0) {
for (int i = 0; i < sizeof(lfs_global_t)/4; i++) {
if (a->u32[i] != 0) {
return false;
}
}
@@ -425,53 +424,26 @@ static inline bool lfs_globaliszero(const lfs_global_t *a) {
}
static inline void lfs_globalzero(lfs_global_t *a) {
memset(a->u16, 0x00, sizeof(lfs_global_t));
}
static inline void lfs_globalones(lfs_global_t *a) {
memset(a->u16, 0xff, sizeof(lfs_global_t));
}
static inline void lfs_globalxormove(lfs_global_t *a,
const lfs_block_t pair[2], uint16_t id) {
a->u16[0] ^= id;
for (int i = 0; i < sizeof(lfs_block_t[2])/2; i++) {
a->u16[1+i] ^= ((uint16_t*)pair)[i];
}
}
static inline void lfs_globalxordeorphaned(lfs_global_t *a, bool deorphaned) {
a->u16[0] ^= deorphaned << 15;
lfs_globalxor(a, a);
}
static inline void lfs_globalfromle32(lfs_global_t *a) {
a->u16[0] = lfs_fromle16(a->u16[0]);
lfs_pairfromle32((lfs_block_t*)&a->u16[1]);
lfs_pairfromle32(a->s.movepair);
a->s.moveid = lfs_fromle16(a->s.moveid);
}
static inline void lfs_globaltole32(lfs_global_t *a) {
a->u16[0] = lfs_tole16(a->u16[0]);
lfs_pairtole32((lfs_block_t*)&a->u16[1]);
}
static inline const lfs_block_t *lfs_globalmovepair(const lfs_t *lfs) {
return (const lfs_block_t*)&lfs->globals.u16[1];
}
static inline uint16_t lfs_globalmoveid(const lfs_t *lfs) {
return 0x3ff & lfs->globals.u16[0];
}
static inline bool lfs_globalisdeorphaned(const lfs_t *lfs) {
return 0x8000 & lfs->globals.u16[0];
lfs_pairtole32(a->s.movepair);
a->s.moveid = lfs_tole16(a->s.moveid);
}
static inline void lfs_globalmove(lfs_t *lfs,
const lfs_block_t pair[2], uint16_t id) {
lfs_global_t diff;
lfs_globalzero(&diff);
lfs_globalxormove(&diff, lfs_globalmovepair(lfs), lfs_globalmoveid(lfs));
lfs_globalxormove(&diff, pair, id);
diff.s.movepair[0] ^= lfs->globals.s.movepair[0] ^ pair[0];
diff.s.movepair[1] ^= lfs->globals.s.movepair[1] ^ pair[1];
diff.s.moveid ^= lfs->globals.s.moveid ^ id;
lfs_globalfromle32(&lfs->locals);
lfs_globalxor(&lfs->locals, &diff);
lfs_globaltole32(&lfs->locals);
@@ -479,11 +451,8 @@ static inline void lfs_globalmove(lfs_t *lfs,
}
static inline void lfs_globaldeorphaned(lfs_t *lfs, bool deorphaned) {
deorphaned ^= lfs_globalisdeorphaned(lfs);
lfs_globalfromle32(&lfs->locals);
lfs_globalxordeorphaned(&lfs->locals, deorphaned);
lfs_globaltole32(&lfs->locals);
lfs_globalxordeorphaned(&lfs->globals, deorphaned);
lfs->locals.s.deorphaned ^= lfs->globals.s.deorphaned ^ deorphaned;
lfs->globals.s.deorphaned ^= lfs->globals.s.deorphaned ^ deorphaned;
}
@@ -696,7 +665,8 @@ static int lfs_commitglobals(lfs_t *lfs, struct lfs_commit *commit,
lfs_globalxor(locals, &lfs->locals);
int err = lfs_commitattr(lfs, commit,
LFS_MKTAG(LFS_TYPE_GLOBALS, 0x3ff, sizeof(lfs_global_t)), locals);
LFS_MKTAG(LFS_TYPE_GLOBALS + locals->s.deorphaned,
0x3ff, sizeof(lfs_global_t)), locals);
lfs_globalxor(locals, &lfs->locals);
return err;
}
@@ -893,6 +863,7 @@ static int32_t lfs_dir_find(lfs_t *lfs,
}
lfs_pairfromle32(temptail);
} else if (lfs_tagsubtype(tag) == LFS_TYPE_GLOBALS) {
templocals.s.deorphaned = (lfs_tagtype(tag) & 1);
err = lfs_bd_read(lfs, dir->pair[0], off+sizeof(tag),
&templocals, sizeof(templocals));
if (err) {
@@ -929,11 +900,11 @@ static int32_t lfs_dir_find(lfs_t *lfs,
// consider what we have good enough
if (dir->off > 0) {
// synthetic move
if (lfs_paircmp(dir->pair, lfs_globalmovepair(lfs)) == 0) {
if (lfs_globalmoveid(lfs) == lfs_tagid(foundtag)) {
if (lfs_paircmp(dir->pair, lfs->globals.s.movepair) == 0) {
if (lfs->globals.s.moveid == lfs_tagid(foundtag)) {
foundtag = LFS_ERR_NOENT;
} else if (lfs_tagisvalid(foundtag) &&
lfs_globalmoveid(lfs) < lfs_tagid(foundtag)) {
lfs->globals.s.moveid < lfs_tagid(foundtag)) {
foundtag -= LFS_MKTAG(0, 1, 0);
}
}
@@ -963,8 +934,8 @@ static int lfs_dir_fetch(lfs_t *lfs,
static int32_t lfs_dir_get(lfs_t *lfs, lfs_mdir_t *dir,
uint32_t getmask, uint32_t gettag, void *buffer) {
int32_t getdiff = 0;
if (lfs_paircmp(dir->pair, lfs_globalmovepair(lfs)) == 0 &&
lfs_tagid(gettag) <= lfs_globalmoveid(lfs)) {
if (lfs_paircmp(dir->pair, lfs->globals.s.movepair) == 0 &&
lfs_tagid(gettag) <= lfs->globals.s.moveid) {
// synthetic moves
getdiff = LFS_MKTAG(0, 1, 0);
}
@@ -1166,18 +1137,17 @@ static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
lfs_mattr_t cancelattr;
lfs_global_t canceldiff;
lfs_globalzero(&canceldiff);
if (lfs_paircmp(dir->pair, lfs_globalmovepair(lfs)) == 0) {
if (lfs_paircmp(dir->pair, lfs->globals.s.movepair) == 0) {
// Wait, we have the move? Just cancel this out here
// We need to, or else the move can become outdated
lfs_globalxormove(&canceldiff,
lfs_globalmovepair(lfs), lfs_globalmoveid(lfs));
lfs_globalxormove(&canceldiff,
(lfs_block_t[2]){0xffffffff, 0xffffffff}, 0x3ff);
canceldiff.s.movepair[0] ^= lfs->globals.s.movepair[0] ^ 0xffffffff;
canceldiff.s.movepair[1] ^= lfs->globals.s.movepair[1] ^ 0xffffffff;
canceldiff.s.moveid ^= lfs->globals.s.moveid ^ 0x3ff;
lfs_globalfromle32(&lfs->locals);
lfs_globalxor(&lfs->locals, &canceldiff);
lfs_globaltole32(&lfs->locals);
cancelattr.tag = LFS_MKTAG(LFS_TYPE_DELETE, lfs_globalmoveid(lfs), 0);
cancelattr.tag = LFS_MKTAG(LFS_TYPE_DELETE, lfs->globals.s.moveid, 0);
cancelattr.next = attrs;
attrs = &cancelattr;
}
@@ -2814,7 +2784,10 @@ static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
lfs->root[0] = 0xffffffff;
lfs->root[1] = 0xffffffff;
lfs->mlist = NULL;
lfs_globalones(&lfs->globals);
lfs->globals.s.movepair[0] = 0xffffffff;
lfs->globals.s.movepair[1] = 0xffffffff;
lfs->globals.s.moveid = 0x3ff;
lfs->globals.s.deorphaned = true;
lfs_globalzero(&lfs->locals);
return 0;
@@ -2920,8 +2893,8 @@ int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
lfs_alloc_ack(lfs);
// load superblock
lfs_mdir_t dir;
err = lfs_dir_fetch(lfs, &dir, (const lfs_block_t[2]){0, 1});
lfs_mdir_t superdir;
err = lfs_dir_fetch(lfs, &superdir, (const lfs_block_t[2]){0, 1});
if (err) {
if (err == LFS_ERR_CORRUPT) {
LFS_ERROR("Invalid superblock at %d %d", 0, 1);
@@ -2930,7 +2903,7 @@ int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
}
lfs_superblock_t superblock;
int32_t res = lfs_dir_get(lfs, &dir, 0x7ffff000,
int32_t res = lfs_dir_get(lfs, &superdir, 0x7ffff000,
LFS_MKTAG(LFS_TYPE_SUPERBLOCK, 0, sizeof(superblock)),
&superblock);
if (res < 0) {
@@ -2951,7 +2924,7 @@ int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
return LFS_ERR_INVAL;
}
res = lfs_dir_get(lfs, &dir, 0x7ffff000,
res = lfs_dir_get(lfs, &superdir, 0x7ffff000,
LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 0, sizeof(lfs->root)),
&lfs->root);
if (res < 0) {
@@ -2990,11 +2963,28 @@ int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
}
// scan for any global updates
err = lfs_fs_scan(lfs);
lfs_mdir_t dir = {.tail = {0, 1}};
while (!lfs_pairisnull(dir.tail)) {
int err = lfs_dir_fetch(lfs, &dir, dir.tail);
if (err) {
return err;
}
// xor together indirect deletes
lfs_globalxor(&lfs->locals, &dir.locals);
}
// update littlefs with globals
lfs_globalfromle32(&lfs->locals);
lfs_globalxor(&lfs->globals, &lfs->locals);
lfs_globalzero(&lfs->locals);
if (!lfs_pairisnull(lfs->globals.s.movepair)) {
LFS_DEBUG("Found move %d %d %d",
lfs->globals.s.movepair[0],
lfs->globals.s.movepair[1],
lfs->globals.s.moveid);
}
return 0;
}
@@ -3186,41 +3176,10 @@ static int lfs_fs_relocate(lfs_t *lfs,
return 0;
}
static int lfs_fs_scan(lfs_t *lfs) {
if (lfs_pairisnull(lfs->root)) {
return 0;
}
// iterate over all directory directory entries
lfs_mdir_t dir = {.tail = {0, 1}};
while (!lfs_pairisnull(dir.tail)) {
int err = lfs_dir_fetch(lfs, &dir, dir.tail);
if (err) {
return err;
}
// xor together indirect deletes
lfs_globalxor(&lfs->locals, &dir.locals);
}
// update littlefs with globals
lfs_globalfromle32(&lfs->locals);
lfs_globalxor(&lfs->globals, &lfs->locals);
lfs_globalzero(&lfs->locals);
if (!lfs_pairisnull(lfs_globalmovepair(lfs))) {
LFS_DEBUG("Found move %d %d %d",
lfs_globalmovepair(lfs)[0],
lfs_globalmovepair(lfs)[1],
lfs_globalmoveid(lfs));
}
return 0;
}
static int lfs_fs_forceconsistency(lfs_t *lfs) {
if (!lfs_globalisdeorphaned(lfs)) {
if (!lfs->globals.s.deorphaned) {
LFS_DEBUG("Found orphans %d",
lfs_globalisdeorphaned(lfs));
lfs->globals.s.deorphaned);
// Fix any orphans
lfs_mdir_t pdir = {.split = true};
@@ -3292,16 +3251,16 @@ static int lfs_fs_forceconsistency(lfs_t *lfs) {
lfs_globaldeorphaned(lfs, false);
}
if (lfs_globalmoveid(lfs) != 0x3ff) {
if (lfs->globals.s.moveid != 0x3ff) {
// Fix bad moves
LFS_DEBUG("Fixing move %d %d %d",
lfs_globalmovepair(lfs)[0],
lfs_globalmovepair(lfs)[1],
lfs_globalmoveid(lfs));
lfs->globals.s.movepair[0],
lfs->globals.s.movepair[1],
lfs->globals.s.moveid);
// fetch and delete the moved entry
lfs_mdir_t movedir;
int err = lfs_dir_fetch(lfs, &movedir, lfs_globalmovepair(lfs));
int err = lfs_dir_fetch(lfs, &movedir, lfs->globals.s.movepair);
if (err) {
return err;
}

9
lfs.h
View File

@@ -287,18 +287,23 @@ typedef struct lfs_cache {
} lfs_cache_t;
typedef union lfs_global {
uint16_t u16[5];
uint32_t u32[3];
struct {
lfs_block_t movepair[2];
uint16_t moveid;
bool deorphaned;
} s;
} lfs_global_t;
typedef struct lfs_mdir {
lfs_block_t pair[2];
lfs_block_t tail[2];
uint32_t rev;
uint32_t etag;
lfs_off_t off;
uint16_t count;
bool erased;
bool split;
lfs_block_t tail[2];
lfs_global_t locals;
} lfs_mdir_t;