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Added simple lfsr_fs_ckmeta/ckdata functions

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These functions provide an easy API for checking all metadata/data
checksums in the filesystem:

  // Check the filesystem for metadata errors
  int lfsr_fs_ckmeta(lfs_t *lfs);

  // Check the filesystem for metadata + data errors
  int lfsr_fs_ckdata(lfs_t *lfs);

These are more-or-less the same as calling lfsr_fs_gc with
LFS_GC_CKMETA/CKDATA, but don't involve the gc/traversal-invalidation
machinery, and may be a bit easier for users to pick up.

---

Unfortunately, for simple wrappers, we're again hit with a somewhat
surprising code cost:

           code          stack
  before: 36288           2680
  after:  36472 (+0.5%)   2680 (+0.0%)

But I think we can again blame the high overhead of LFS_TRAVERSAL/
lfsr_mtree_gc. We should look into reducing/deduplicating this logic...
This commit is contained in:
Christopher Haster
2024-07-15 18:05:21 -05:00
parent 83f2a3c7fc
commit 4fe46a983f
3 changed files with 324 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lfs.c
+37
View File
@@ -13024,6 +13024,43 @@ int lfsr_fs_mkconsistent(lfs_t *lfs) {
return 0;
}
// check the filesystem for metadata errors
int lfsr_fs_ckmeta(lfs_t *lfs) {
// we leave this up to lfsr_mtree_gc
lfsr_traversal_t t = LFSR_TRAVERSAL(LFS_T_CKMETA);
while (true) {
int err = lfsr_mtree_gc(lfs, &t,
NULL, NULL);
if (err) {
if (err == LFS_ERR_NOENT) {
break;
}
return err;
}
}
return 0;
}
// check the filesystem for metadata + data errors
int lfsr_fs_ckdata(lfs_t *lfs) {
// we leave this up to lfsr_mtree_gc
lfsr_traversal_t t = LFSR_TRAVERSAL(LFS_T_CKMETA | LFS_T_CKDATA);
while (true) {
int err = lfsr_mtree_gc(lfs, &t,
NULL, NULL);
if (err) {
if (err == LFS_ERR_NOENT) {
break;
}
return err;
}
}
return 0;
}
// perform any pending janitorial work
int lfsr_fs_gc(lfs_t *lfs, uint32_t flags) {
// some flags don't make sense when only traversing the mtree
LFS_ASSERT(!lfsr_t_ismtreeonly(flags) || !lfsr_t_islookahead(flags));
lfs.h
+17 -1
View File
@@ -1165,7 +1165,23 @@ int lfsr_fs_mkconsistent(lfs_t *lfs);
#endif
#ifndef LFS_READONLY
// Attempt any janitorial work that may be pending.
// Check the filesystem for metadata errors
//
// Returns LFS_ERR_CORRUPT if a checksum mismatch is found, or a negative
// error code on failure.
int lfsr_fs_ckmeta(lfs_t *lfs);
#endif
#ifndef LFS_READONLY
// Check the filesystem for metadata + data errors
//
// Returns LFS_ERR_CORRUPT if a checksum mismatch is found, or a negative
// error code on failure.
int lfsr_fs_ckdata(lfs_t *lfs);
#endif
#ifndef LFS_READONLY
// Perform any janitorial work that may be pending.
//
// The exact janitorial work depends on the provided flags. Note multiple
// calls may be required to complete all janitorial work.
tests/test_gc.toml
+270
View File
@@ -779,6 +779,99 @@ code = '''
lfsr_unmount(&lfs) => 0;
'''
# test that an explicit lfsr_fs_mkconsistent call also works, this calls
# the same logic internally
[cases.test_gc_mkconsistent_explicit]
defines.SIZE = 'FILE_BUFFER_SIZE/2'
# <=2 => grm-able
# >2 => requires orphans
defines.ORPHANS = [1, 2, 3, 100]
code = '''
lfs_t lfs;
lfsr_format(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
uint32_t prng = 42;
// create two files
lfsr_file_t file1;
lfsr_file_open(&lfs, &file1, "cuttlefish",
LFS_O_RDWR | LFS_O_CREAT | LFS_O_EXCL) => 0;
uint8_t wbuf1[SIZE];
for (lfs_size_t j = 0; j < SIZE; j++) {
wbuf1[j] = 'a' + (TEST_PRNG(&prng) % 26);
}
lfsr_file_write(&lfs, &file1, wbuf1, SIZE) => SIZE;
lfsr_file_sync(&lfs, &file1) => 0;
lfsr_file_t file2;
lfsr_file_open(&lfs, &file2, "octopus",
LFS_O_RDWR | LFS_O_CREAT | LFS_O_EXCL) => 0;
uint8_t wbuf2[SIZE];
for (lfs_size_t j = 0; j < SIZE; j++) {
wbuf2[j] = 'a' + (TEST_PRNG(&prng) % 26);
}
lfsr_file_write(&lfs, &file2, wbuf2, SIZE) => SIZE;
lfsr_file_sync(&lfs, &file2) => 0;
// create this many orphaned files
//
// anytime we close a not-yet-created desync file, we create an
// orphan, but note we need these to be different files, and we need
// to close them after all open calls, otherwise we just end up with
// one orphan (littlefs is eager to clean up orphans)
//
lfsr_file_t orphans[ORPHANS];
for (lfs_size_t i = 0; i < ORPHANS; i++) {
char name[256];
sprintf(name, "jellyfish%03x", i);
lfsr_file_open(&lfs, &orphans[i], name,
LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL | LFS_O_DESYNC) => 0;
}
for (lfs_size_t i = 0; i < ORPHANS; i++) {
lfsr_file_close(&lfs, &orphans[i]) => 0;
}
// expect dirty initial state or else our test doesn't work
struct lfs_fsinfo fsinfo;
lfsr_fs_stat(&lfs, &fsinfo) => 0;
assert(fsinfo.flags & LFS_I_INCONSISTENT);
assert(lfs.omdirs != &lfs.gc.o.o);
// call lfsr_fs_mkconsistent
lfsr_fs_mkconsistent(&lfs) => 0;
// we should have made progress
lfsr_fs_stat(&lfs, &fsinfo) => 0;
assert(!(fsinfo.flags & LFS_I_INCONSISTENT));
// check we can still read the files
for (int remount = 0; remount < 2; remount++) {
// remount?
if (remount) {
lfsr_file_close(&lfs, &file1) => 0;
lfsr_file_close(&lfs, &file2) => 0;
lfsr_unmount(&lfs) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_file_open(&lfs, &file1, "cuttlefish", LFS_O_RDONLY) => 0;
lfsr_file_open(&lfs, &file2, "octopus", LFS_O_RDONLY) => 0;
}
lfsr_file_rewind(&lfs, &file1) => 0;
uint8_t rbuf[SIZE];
lfsr_file_read(&lfs, &file1, rbuf, SIZE) => SIZE;
assert(memcmp(rbuf, wbuf1, SIZE) == 0);
lfsr_file_rewind(&lfs, &file2) => 0;
lfsr_file_read(&lfs, &file2, rbuf, SIZE) => SIZE;
assert(memcmp(rbuf, wbuf2, SIZE) == 0);
}
lfsr_file_close(&lfs, &file1) => 0;
lfsr_file_close(&lfs, &file2) => 0;
lfsr_unmount(&lfs) => 0;
'''
# test that mkconsistent dirtying still works with the GC API
[cases.test_gc_mkconsistent_mutation]
defines.GC_STEPS = 1
@@ -1329,6 +1422,183 @@ code = '''
done:;
'''
# test that our explicit functions (lfsr_fs_ckmeta/ckdata) work as well,
# these call the same logic internally
[cases.test_gc_ckmeta_explicit]
defines.N = [1, 2, 4, 8, 16, 32, 64]
defines.SIZE = [
'0',
'FILE_BUFFER_SIZE/2',
'2*FILE_BUFFER_SIZE',
'BLOCK_SIZE/2',
'BLOCK_SIZE',
'2*BLOCK_SIZE',
'8*BLOCK_SIZE',
]
if = '(SIZE*N)/BLOCK_SIZE <= 32'
code = '''
lfs_block_t i = 0;
while (true) {
// a bit hacky, but this catches infinite loops
assert(i < 2*BLOCK_COUNT);
lfs_t lfs;
lfsr_format(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
// create an interesting filesystem
uint32_t prng = 42;
for (lfs_size_t i = 0; i < N; i++) {
char name[256];
sprintf(name, "squid%03x", i);
uint8_t wbuf[SIZE];
for (lfs_size_t j = 0; j < SIZE; j++) {
wbuf[j] = 'a' + (TEST_PRNG(&prng) % 26);
}
lfsr_file_t file;
lfsr_file_open(&lfs, &file, name,
LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
lfsr_file_write(&lfs, &file, wbuf, SIZE) => SIZE;
lfsr_file_close(&lfs, &file) => 0;
}
// traverse to find blocks
lfsr_traversal_t t;
lfsr_traversal_open(&lfs, &t, 0) => 0;
lfs_block_t k = 0;
for (lfs_block_t j = 0;; j++) {
assert(j < 2*BLOCK_COUNT);
struct lfs_tinfo tinfo;
int err = lfsr_traversal_read(&lfs, &t, &tinfo);
assert(!err || err == LFS_ERR_NOENT);
if (err == LFS_ERR_NOENT) {
lfsr_traversal_close(&lfs, &t) => 0;
lfsr_unmount(&lfs) => 0;
goto done;
}
// this gets a bit tricky be cause we need to clobber both
// blocks in mdir pairs
if (tinfo.btype == LFS_BTYPE_MDIR
|| tinfo.btype == LFS_BTYPE_BTREE) {
if (k == i || k == i+1) {
// clobber this block
printf("clobbering 0x%x\n", tinfo.block);
uint8_t clobber_buf[BLOCK_SIZE];
memset(clobber_buf, 0xcc, BLOCK_SIZE);
CFG->erase(CFG, tinfo.block) => 0;
CFG->prog(CFG, tinfo.block, 0,
clobber_buf, BLOCK_SIZE) => 0;
if (tinfo.btype != LFS_BTYPE_MDIR || k == i+1) {
i += (tinfo.btype == LFS_BTYPE_MDIR) ? 2 : 1;
lfsr_traversal_close(&lfs, &t) => 0;
goto clobbered;
}
}
k += 1;
}
}
clobbered:;
// lfsr_fs_ckmeta should find the clobbered block
lfsr_fs_ckmeta(&lfs) => LFS_ERR_CORRUPT;
lfsr_unmount(&lfs) => 0;
}
done:;
'''
[cases.test_gc_ckdata_explicit]
defines.N = [1, 2, 4, 8, 16, 32, 64]
defines.SIZE = [
'0',
'FILE_BUFFER_SIZE/2',
'2*FILE_BUFFER_SIZE',
'BLOCK_SIZE/2',
'BLOCK_SIZE',
'2*BLOCK_SIZE',
'8*BLOCK_SIZE',
]
if = '(SIZE*N)/BLOCK_SIZE <= 32'
code = '''
lfs_block_t i = 0;
while (true) {
// a bit hacky, but this catches infinite loops
assert(i < 2*BLOCK_COUNT);
lfs_t lfs;
lfsr_format(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
// create an interesting filesystem
uint32_t prng = 42;
for (lfs_size_t i = 0; i < N; i++) {
char name[256];
sprintf(name, "squid%03x", i);
uint8_t wbuf[SIZE];
for (lfs_size_t j = 0; j < SIZE; j++) {
wbuf[j] = 'a' + (TEST_PRNG(&prng) % 26);
}
lfsr_file_t file;
lfsr_file_open(&lfs, &file, name,
LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
lfsr_file_write(&lfs, &file, wbuf, SIZE) => SIZE;
lfsr_file_close(&lfs, &file) => 0;
}
// traverse to find blocks
lfsr_traversal_t t;
lfsr_traversal_open(&lfs, &t, 0) => 0;
lfs_block_t k = 0;
for (lfs_block_t j = 0;; j++) {
assert(j < 2*BLOCK_COUNT);
struct lfs_tinfo tinfo;
int err = lfsr_traversal_read(&lfs, &t, &tinfo);
assert(!err || err == LFS_ERR_NOENT);
if (err == LFS_ERR_NOENT) {
lfsr_traversal_close(&lfs, &t) => 0;
lfsr_unmount(&lfs) => 0;
goto done;
}
// this gets a bit tricky be cause we need to clobber both
// blocks in mdir pairs
if (tinfo.btype == LFS_BTYPE_MDIR
|| tinfo.btype == LFS_BTYPE_BTREE
|| tinfo.btype == LFS_BTYPE_DATA) {
if (k == i || k == i+1) {
// clobber this block
printf("clobbering 0x%x\n", tinfo.block);
uint8_t clobber_buf[BLOCK_SIZE];
memset(clobber_buf, 0xcc, BLOCK_SIZE);
CFG->erase(CFG, tinfo.block) => 0;
CFG->prog(CFG, tinfo.block, 0,
clobber_buf, BLOCK_SIZE) => 0;
if (tinfo.btype != LFS_BTYPE_MDIR || k == i+1) {
i += (tinfo.btype == LFS_BTYPE_MDIR) ? 2 : 1;
lfsr_traversal_close(&lfs, &t) => 0;
goto clobbered;
}
}
k += 1;
}
}
clobbered:;
// lfsr_fs_ckdata should find the clobbered block
lfsr_fs_ckdata(&lfs) => LFS_ERR_CORRUPT;
lfsr_unmount(&lfs) => 0;
}
done:;
'''
# pseudo-fuzz test that dirtying still works with the GC API
[cases.test_gc_mutation]