Files
littlefs/tests/test_bmap.toml
T
Christopher Haster 726cccfe76 bmap: Tweaked bmapcache algo to piggyback on mdir commits
There's really no reason to immediately commit the bmap to disk, at
least no until the first mdir commit, when we need to at least discard
the previous bmap state.

We already do all the gstate handling in lfs3_mdir_commit anyways, and
piggybacking on mdir commit lets us get rid of the annoying extra mdir
param in lfs3_alloc_ckpoint.

This does mean a slightly higher risk of needing to re-rebuild the bmap
after a powerloss, but in theory only if the user does something weird
like writing to a file and never calling sync. Most on-disk operations
terminate in an mdir commit as that's how any state change becomes
atomically visibile in littlefs.

Saves a nice bit of stack:

                code          stack          ctx
  before:      36920           2368          684
  after:       36920 (+0.0%)   2368 (+0.0%)  684 (+0.0%)

                code          stack          ctx
  bmap before: 38552           2472          812
  bmap after:  38464 (-0.2%)   2400 (-2.9%)  812 (+0.0%)
2025-10-01 17:56:16 -05:00

378 lines
12 KiB
TOML

# Test some low-level block-map operations
after = ['test_btree', 'test_mtree']
ifdef = 'LFS3_BMAP'
# test simple set operations
[cases.test_bmap_set_split]
in = 'lfs3.c'
code = '''
lfs3_t lfs3;
lfs3_format(&lfs3, LFS3_F_RDWR, CFG) => 0;
lfs3_mount(&lfs3, LFS3_M_RDWR, CFG) => 0;
lfs3_alloc_ckpoint(&lfs3);
// create an initial bmap
lfs3_btree_t bmap;
lfs3_btree_init(&bmap);
lfs3_bmap_commit(&lfs3, &bmap, 0, LFS3_RATTRS(
LFS3_RATTR(LFS3_TAG_BMFREE, +BLOCK_COUNT))) => 0;
// set some blocks as in-use, avoid any weird merges for now
lfs3_bmap_set(&lfs3, &bmap, 6, LFS3_TAG_BMINUSE) => 0;
lfs3_bmap_set(&lfs3, &bmap, 8, LFS3_TAG_BMINUSE) => 0;
lfs3_bmap_set(&lfs3, &bmap, 10, LFS3_TAG_BMINUSE) => 0;
printf("bmap: w%d 0x%x.%x\n",
bmap.r.weight,
bmap.r.blocks[0],
bmap.r.trunk);
// weight should stay the same
assert(bmap.r.weight == BLOCK_COUNT);
// check ranges
lfs3_bid_t bid_;
lfs3_bid_t weight_;
lfs3_bmap_lookupnext(&lfs3, &bmap, 0,
&bid_, &weight_) => LFS3_TAG_BMFREE;
assert(bid_ == 5);
assert(weight_ == 6);
lfs3_bmap_lookupnext(&lfs3, &bmap, 6,
&bid_, &weight_) => LFS3_TAG_BMINUSE;
assert(bid_ == 6);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 7,
&bid_, &weight_) => LFS3_TAG_BMFREE;
assert(bid_ == 7);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 8,
&bid_, &weight_) => LFS3_TAG_BMINUSE;
assert(bid_ == 8);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 9,
&bid_, &weight_) => LFS3_TAG_BMFREE;
assert(bid_ == 9);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 10,
&bid_, &weight_) => LFS3_TAG_BMINUSE;
assert(bid_ == 10);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 11,
&bid_, &weight_) => LFS3_TAG_BMFREE;
assert(bid_ == BLOCK_COUNT-1);
assert(weight_ == BLOCK_COUNT-11);
lfs3_unmount(&lfs3) => 0;
'''
[cases.test_bmap_set_replace]
in = 'lfs3.c'
code = '''
lfs3_t lfs3;
lfs3_format(&lfs3, LFS3_F_RDWR, CFG) => 0;
lfs3_mount(&lfs3, LFS3_M_RDWR, CFG) => 0;
lfs3_alloc_ckpoint(&lfs3);
// create an initial bmap
lfs3_btree_t bmap;
lfs3_btree_init(&bmap);
lfs3_bmap_commit(&lfs3, &bmap, 0, LFS3_RATTRS(
LFS3_RATTR(LFS3_TAG_BMFREE, +BLOCK_COUNT))) => 0;
// set some blocks as in-use, avoid any weird merges for now
lfs3_bmap_set(&lfs3, &bmap, 6, LFS3_TAG_BMINUSE) => 0;
lfs3_bmap_set(&lfs3, &bmap, 8, LFS3_TAG_BMINUSE) => 0;
lfs3_bmap_set(&lfs3, &bmap, 10, LFS3_TAG_BMINUSE) => 0;
// replace those blocks as bad, this tests deleting ranges
lfs3_bmap_set(&lfs3, &bmap, 6, LFS3_TAG_BMINFLIGHT) => 0;
lfs3_bmap_set(&lfs3, &bmap, 8, LFS3_TAG_BMINFLIGHT) => 0;
lfs3_bmap_set(&lfs3, &bmap, 10, LFS3_TAG_BMINFLIGHT) => 0;
printf("bmap: w%d 0x%x.%x\n",
bmap.r.weight,
bmap.r.blocks[0],
bmap.r.trunk);
// weight should stay the same
assert(bmap.r.weight == BLOCK_COUNT);
// check ranges
lfs3_bid_t bid_;
lfs3_bid_t weight_;
lfs3_bmap_lookupnext(&lfs3, &bmap, 0,
&bid_, &weight_) => LFS3_TAG_BMFREE;
assert(bid_ == 5);
assert(weight_ == 6);
lfs3_bmap_lookupnext(&lfs3, &bmap, 6,
&bid_, &weight_) => LFS3_TAG_BMINFLIGHT;
assert(bid_ == 6);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 7,
&bid_, &weight_) => LFS3_TAG_BMFREE;
assert(bid_ == 7);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 8,
&bid_, &weight_) => LFS3_TAG_BMINFLIGHT;
assert(bid_ == 8);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 9,
&bid_, &weight_) => LFS3_TAG_BMFREE;
assert(bid_ == 9);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 10,
&bid_, &weight_) => LFS3_TAG_BMINFLIGHT;
assert(bid_ == 10);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 11,
&bid_, &weight_) => LFS3_TAG_BMFREE;
assert(bid_ == BLOCK_COUNT-1);
assert(weight_ == BLOCK_COUNT-11);
lfs3_unmount(&lfs3) => 0;
'''
[cases.test_bmap_set_merge]
in = 'lfs3.c'
code = '''
lfs3_t lfs3;
lfs3_format(&lfs3, LFS3_F_RDWR, CFG) => 0;
lfs3_mount(&lfs3, LFS3_M_RDWR, CFG) => 0;
lfs3_alloc_ckpoint(&lfs3);
// create an initial bmap
lfs3_btree_t bmap;
lfs3_btree_init(&bmap);
lfs3_bmap_commit(&lfs3, &bmap, 0, LFS3_RATTRS(
LFS3_RATTR(LFS3_TAG_BMFREE, +BLOCK_COUNT))) => 0;
// set some blocks as in-use, avoid any weird merges for now
lfs3_bmap_set(&lfs3, &bmap, 6, LFS3_TAG_BMINUSE) => 0;
lfs3_bmap_set(&lfs3, &bmap, 8, LFS3_TAG_BMINUSE) => 0;
lfs3_bmap_set(&lfs3, &bmap, 10, LFS3_TAG_BMINUSE) => 0;
lfs3_bmap_set(&lfs3, &bmap, 12, LFS3_TAG_BMINUSE) => 0;
// set neighboring blocks as in-use, triggering merges
lfs3_bmap_set(&lfs3, &bmap, 5, LFS3_TAG_BMINUSE) => 0;
lfs3_bmap_set(&lfs3, &bmap, 9, LFS3_TAG_BMINUSE) => 0;
lfs3_bmap_set(&lfs3, &bmap, 13, LFS3_TAG_BMINUSE) => 0;
printf("bmap: w%d 0x%x.%x\n",
bmap.r.weight,
bmap.r.blocks[0],
bmap.r.trunk);
// weight should stay the same
assert(bmap.r.weight == BLOCK_COUNT);
// check ranges
lfs3_bid_t bid_;
lfs3_bid_t weight_;
lfs3_bmap_lookupnext(&lfs3, &bmap, 0,
&bid_, &weight_) => LFS3_TAG_BMFREE;
assert(bid_ == 4);
assert(weight_ == 5);
lfs3_bmap_lookupnext(&lfs3, &bmap, 5,
&bid_, &weight_) => LFS3_TAG_BMINUSE;
assert(bid_ == 6);
assert(weight_ == 2);
lfs3_bmap_lookupnext(&lfs3, &bmap, 7,
&bid_, &weight_) => LFS3_TAG_BMFREE;
assert(bid_ == 7);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 8,
&bid_, &weight_) => LFS3_TAG_BMINUSE;
assert(bid_ == 10);
assert(weight_ == 3);
lfs3_bmap_lookupnext(&lfs3, &bmap, 11,
&bid_, &weight_) => LFS3_TAG_BMFREE;
assert(bid_ == 11);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 12,
&bid_, &weight_) => LFS3_TAG_BMINUSE;
assert(bid_ == 13);
assert(weight_ == 2);
lfs3_bmap_lookupnext(&lfs3, &bmap, 14,
&bid_, &weight_) => LFS3_TAG_BMFREE;
assert(bid_ == BLOCK_COUNT-1);
assert(weight_ == BLOCK_COUNT-14);
lfs3_unmount(&lfs3) => 0;
'''
[cases.test_bmap_set_noop]
in = 'lfs3.c'
code = '''
lfs3_t lfs3;
lfs3_format(&lfs3, LFS3_F_RDWR, CFG) => 0;
lfs3_mount(&lfs3, LFS3_M_RDWR, CFG) => 0;
lfs3_alloc_ckpoint(&lfs3);
// create an initial bmap
lfs3_btree_t bmap;
lfs3_btree_init(&bmap);
lfs3_bmap_commit(&lfs3, &bmap, 0, LFS3_RATTRS(
LFS3_RATTR(LFS3_TAG_BMFREE, +BLOCK_COUNT))) => 0;
// set some blocks as in-use, avoid any weird merges for now
lfs3_bmap_set(&lfs3, &bmap, 6, LFS3_TAG_BMINUSE) => 0;
lfs3_bmap_set(&lfs3, &bmap, 8, LFS3_TAG_BMINUSE) => 0;
lfs3_bmap_set(&lfs3, &bmap, 10, LFS3_TAG_BMINUSE) => 0;
// test a bunch of noops
lfs3_bmap_set(&lfs3, &bmap, 6, LFS3_TAG_BMINUSE) => 0;
lfs3_bmap_set(&lfs3, &bmap, 7, LFS3_TAG_BMFREE) => 0;
lfs3_bmap_set(&lfs3, &bmap, 8, LFS3_TAG_BMINUSE) => 0;
lfs3_bmap_set(&lfs3, &bmap, 9, LFS3_TAG_BMFREE) => 0;
lfs3_bmap_set(&lfs3, &bmap, 10, LFS3_TAG_BMINUSE) => 0;
printf("bmap: w%d 0x%x.%x\n",
bmap.r.weight,
bmap.r.blocks[0],
bmap.r.trunk);
// weight should stay the same
assert(bmap.r.weight == BLOCK_COUNT);
// check ranges
lfs3_bid_t bid_;
lfs3_bid_t weight_;
lfs3_bmap_lookupnext(&lfs3, &bmap, 0,
&bid_, &weight_) => LFS3_TAG_BMFREE;
assert(bid_ == 5);
assert(weight_ == 6);
lfs3_bmap_lookupnext(&lfs3, &bmap, 6,
&bid_, &weight_) => LFS3_TAG_BMINUSE;
assert(bid_ == 6);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 7,
&bid_, &weight_) => LFS3_TAG_BMFREE;
assert(bid_ == 7);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 8,
&bid_, &weight_) => LFS3_TAG_BMINUSE;
assert(bid_ == 8);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 9,
&bid_, &weight_) => LFS3_TAG_BMFREE;
assert(bid_ == 9);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 10,
&bid_, &weight_) => LFS3_TAG_BMINUSE;
assert(bid_ == 10);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 11,
&bid_, &weight_) => LFS3_TAG_BMFREE;
assert(bid_ == BLOCK_COUNT-1);
assert(weight_ == BLOCK_COUNT-11);
lfs3_unmount(&lfs3) => 0;
'''
[cases.test_bmap_set_bounds]
in = 'lfs3.c'
code = '''
lfs3_t lfs3;
lfs3_format(&lfs3, LFS3_F_RDWR, CFG) => 0;
lfs3_mount(&lfs3, LFS3_M_RDWR, CFG) => 0;
lfs3_alloc_ckpoint(&lfs3);
// create an initial bmap
lfs3_btree_t bmap;
lfs3_btree_init(&bmap);
lfs3_bmap_commit(&lfs3, &bmap, 0, LFS3_RATTRS(
LFS3_RATTR(LFS3_TAG_BMFREE, +BLOCK_COUNT))) => 0;
// test that setting the first and last blocks don't break anything
//
// though in theory blocks 0x{0,1} are immutable...
lfs3_bmap_set(&lfs3, &bmap, 0, LFS3_TAG_BMINUSE) => 0;
lfs3_bmap_set(&lfs3, &bmap, BLOCK_COUNT-1, LFS3_TAG_BMINUSE) => 0;
printf("bmap: w%d 0x%x.%x\n",
bmap.r.weight,
bmap.r.blocks[0],
bmap.r.trunk);
// weight should stay the same
assert(bmap.r.weight == BLOCK_COUNT);
// check ranges
lfs3_bid_t bid_;
lfs3_bid_t weight_;
lfs3_bmap_lookupnext(&lfs3, &bmap, 0,
&bid_, &weight_) => LFS3_TAG_BMINUSE;
assert(bid_ == 0);
assert(weight_ == 1);
lfs3_bmap_lookupnext(&lfs3, &bmap, 1,
&bid_, &weight_) => LFS3_TAG_BMFREE;
assert(bid_ == BLOCK_COUNT-2);
assert(weight_ == BLOCK_COUNT-2);
lfs3_bmap_lookupnext(&lfs3, &bmap, BLOCK_COUNT-1,
&bid_, &weight_) => LFS3_TAG_BMINUSE;
assert(bid_ == BLOCK_COUNT-1);
assert(weight_ == 1);
lfs3_unmount(&lfs3) => 0;
'''
[cases.test_bmap_set_fuzz]
defines.N = [1, 2, 4, 8, 16, 32, 64, 128, 256, 512]
defines.TYPES = [2, 3, 4]
defines.SEED = 'range(20)'
fuzz = 'SEED'
in = 'lfs3.c'
code = '''
lfs3_t lfs3;
lfs3_format(&lfs3, LFS3_F_RDWR, CFG) => 0;
lfs3_mount(&lfs3, LFS3_M_RDWR, CFG) => 0;
lfs3_alloc_ckpoint(&lfs3);
// create an initial bmap
lfs3_btree_t bmap;
lfs3_btree_init(&bmap);
lfs3_bmap_commit(&lfs3, &bmap, 0, LFS3_RATTRS(
LFS3_RATTR(LFS3_TAG_BMFREE, +BLOCK_COUNT))) => 0;
// create a simulation to compare against
lfs3_tag_t *sim = malloc(BLOCK_COUNT*sizeof(lfs3_tag_t));
for (lfs3_size_t i = 0; i < BLOCK_COUNT; i++) {
sim[i] = LFS3_TAG_BMFREE;
}
uint32_t prng = SEED;
for (lfs3_size_t i = 0; i < N; i++) {
// choose a pseudo-random block
lfs3_block_t block = TEST_PRNG(&prng) % BLOCK_COUNT;
// and pseudo-random bmap type
lfs3_tag_t tag = LFS3_TAG_BMRANGE + (TEST_PRNG(&prng) % TYPES);
// set in bmap
lfs3_bmap_set(&lfs3, &bmap, block, tag) => 0;
// and set in sim
sim[block] = tag;
}
printf("bmap: w%d 0x%x.%x\n",
bmap.r.weight,
bmap.r.blocks[0],
bmap.r.trunk);
// check if bmap matches sim
lfs3_size_t i = 0;
while (i < BLOCK_COUNT) {
// we need to convert our sim's raw blocks to compressed ranges,
// in theory our bmap is optimal
lfs3_tag_t tag = sim[i];
lfs3_size_t d = 1;
while (i+d < BLOCK_COUNT && sim[i+d] == tag) {
d += 1;
}
// does our bmap contain the optimal range?
lfs3_bid_t bid_;
lfs3_bid_t weight_;
lfs3_bmap_lookupnext(&lfs3, &bmap, i,
&bid_, &weight_) => tag;
assert(bid_ == i+(weight_-1));
assert(weight_ == d);
i += d;
}
free(sim);
lfs3_unmount(&lfs3) => 0;
'''