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Merge pull request #966 from BrianPugh/fix-divide-by-zero-full-filesy…
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Fix DivideByZero exception when filesystem is completely full.
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@geky
geky committed Apr 17, 2024
2 parents 4dd30c1 + 1bc1493 commit 68d28b5
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Showing 3 changed files with 62 additions and 25 deletions.
2 changes: 1 addition & 1 deletion lfs.c
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Original file line number Diff line number Diff line change
Expand Up @@ -688,7 +688,7 @@ static int lfs_alloc(lfs_t *lfs, lfs_block_t *block) {
if (lfs->lookahead.ckpoint <= 0) {
LFS_ERROR("No more free space 0x%"PRIx32,
(lfs->lookahead.start + lfs->lookahead.next)
% lfs->cfg->block_count);
% lfs->block_count);
return LFS_ERR_NOSPC;
}

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16 changes: 9 additions & 7 deletions lfs.h
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Original file line number Diff line number Diff line change
Expand Up @@ -59,7 +59,8 @@ typedef uint32_t lfs_block_t;
#endif

// Maximum size of custom attributes in bytes, may be redefined, but there is
// no real benefit to using a smaller LFS_ATTR_MAX. Limited to <= 1022.
// no real benefit to using a smaller LFS_ATTR_MAX. Limited to <= 1022. Stored
// in superblock and must be respected by other littlefs drivers.
#ifndef LFS_ATTR_MAX
#define LFS_ATTR_MAX 1022
#endif
Expand Down Expand Up @@ -203,7 +204,8 @@ struct lfs_config {
// program sizes.
lfs_size_t block_size;

// Number of erasable blocks on the device.
// Number of erasable blocks on the device. Defaults to block_count stored
// on disk when zero.
lfs_size_t block_count;

// Number of erase cycles before littlefs evicts metadata logs and moves
Expand Down Expand Up @@ -252,18 +254,18 @@ struct lfs_config {

// Optional upper limit on length of file names in bytes. No downside for
// larger names except the size of the info struct which is controlled by
// the LFS_NAME_MAX define. Defaults to LFS_NAME_MAX when zero. Stored in
// superblock and must be respected by other littlefs drivers.
// the LFS_NAME_MAX define. Defaults to LFS_NAME_MAX or name_max stored on
// disk when zero.
lfs_size_t name_max;

// Optional upper limit on files in bytes. No downside for larger files
// but must be <= LFS_FILE_MAX. Defaults to LFS_FILE_MAX when zero. Stored
// in superblock and must be respected by other littlefs drivers.
// but must be <= LFS_FILE_MAX. Defaults to LFS_FILE_MAX or file_max stored
// on disk when zero.
lfs_size_t file_max;

// Optional upper limit on custom attributes in bytes. No downside for
// larger attributes size but must be <= LFS_ATTR_MAX. Defaults to
// LFS_ATTR_MAX when zero.
// LFS_ATTR_MAX or attr_max stored on disk when zero.
lfs_size_t attr_max;

// Optional upper limit on total space given to metadata pairs in bytes. On
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69 changes: 52 additions & 17 deletions tests/test_alloc.toml
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Original file line number Diff line number Diff line change
Expand Up @@ -8,17 +8,22 @@ defines.FILES = 3
defines.SIZE = '(((BLOCK_SIZE-8)*(BLOCK_COUNT-6)) / FILES)'
defines.GC = [false, true]
defines.COMPACT_THRESH = ['-1', '0', 'BLOCK_SIZE/2']
defines.INFER_BC = [false, true]
code = '''
const char *names[] = {"bacon", "eggs", "pancakes"};
lfs_file_t files[FILES];

lfs_t lfs;
lfs_format(&lfs, cfg) => 0;
lfs_mount(&lfs, cfg) => 0;
struct lfs_config cfg_ = *cfg;
if (INFER_BC) {
cfg_.block_count = 0;
}
lfs_mount(&lfs, &cfg_) => 0;
lfs_mkdir(&lfs, "breakfast") => 0;
lfs_unmount(&lfs) => 0;

lfs_mount(&lfs, cfg) => 0;
lfs_mount(&lfs, &cfg_) => 0;
for (int n = 0; n < FILES; n++) {
char path[1024];
sprintf(path, "breakfast/%s", names[n]);
Expand All @@ -39,7 +44,7 @@ code = '''
}
lfs_unmount(&lfs) => 0;

lfs_mount(&lfs, cfg) => 0;
lfs_mount(&lfs, &cfg_) => 0;
for (int n = 0; n < FILES; n++) {
char path[1024];
sprintf(path, "breakfast/%s", names[n]);
Expand All @@ -62,17 +67,22 @@ defines.FILES = 3
defines.SIZE = '(((BLOCK_SIZE-8)*(BLOCK_COUNT-6)) / FILES)'
defines.GC = [false, true]
defines.COMPACT_THRESH = ['-1', '0', 'BLOCK_SIZE/2']
defines.INFER_BC = [false, true]
code = '''
const char *names[] = {"bacon", "eggs", "pancakes"};

lfs_t lfs;
lfs_format(&lfs, cfg) => 0;
lfs_mount(&lfs, cfg) => 0;
struct lfs_config cfg_ = *cfg;
if (INFER_BC) {
cfg_.block_count = 0;
}
lfs_mount(&lfs, &cfg_) => 0;
lfs_mkdir(&lfs, "breakfast") => 0;
lfs_unmount(&lfs) => 0;

for (int n = 0; n < FILES; n++) {
lfs_mount(&lfs, cfg) => 0;
lfs_mount(&lfs, &cfg_) => 0;
char path[1024];
sprintf(path, "breakfast/%s", names[n]);
lfs_file_t file;
Expand All @@ -91,7 +101,7 @@ code = '''
lfs_unmount(&lfs) => 0;
}

lfs_mount(&lfs, cfg) => 0;
lfs_mount(&lfs, &cfg_) => 0;
for (int n = 0; n < FILES; n++) {
char path[1024];
sprintf(path, "breakfast/%s", names[n]);
Expand All @@ -113,19 +123,24 @@ code = '''
defines.FILES = 3
defines.SIZE = '(((BLOCK_SIZE-8)*(BLOCK_COUNT-6)) / FILES)'
defines.CYCLES = [1, 10]
defines.INFER_BC = [false, true]
code = '''
const char *names[] = {"bacon", "eggs", "pancakes"};
lfs_file_t files[FILES];

lfs_t lfs;
lfs_format(&lfs, cfg) => 0;
struct lfs_config cfg_ = *cfg;
if (INFER_BC) {
cfg_.block_count = 0;
}

for (int c = 0; c < CYCLES; c++) {
lfs_mount(&lfs, cfg) => 0;
lfs_mount(&lfs, &cfg_) => 0;
lfs_mkdir(&lfs, "breakfast") => 0;
lfs_unmount(&lfs) => 0;

lfs_mount(&lfs, cfg) => 0;
lfs_mount(&lfs, &cfg_) => 0;
for (int n = 0; n < FILES; n++) {
char path[1024];
sprintf(path, "breakfast/%s", names[n]);
Expand All @@ -143,7 +158,7 @@ code = '''
}
lfs_unmount(&lfs) => 0;

lfs_mount(&lfs, cfg) => 0;
lfs_mount(&lfs, &cfg_) => 0;
for (int n = 0; n < FILES; n++) {
char path[1024];
sprintf(path, "breakfast/%s", names[n]);
Expand All @@ -159,7 +174,7 @@ code = '''
}
lfs_unmount(&lfs) => 0;

lfs_mount(&lfs, cfg) => 0;
lfs_mount(&lfs, &cfg_) => 0;
for (int n = 0; n < FILES; n++) {
char path[1024];
sprintf(path, "breakfast/%s", names[n]);
Expand All @@ -175,19 +190,24 @@ code = '''
defines.FILES = 3
defines.SIZE = '(((BLOCK_SIZE-8)*(BLOCK_COUNT-6)) / FILES)'
defines.CYCLES = [1, 10]
defines.INFER_BC = [false, true]
code = '''
const char *names[] = {"bacon", "eggs", "pancakes"};

lfs_t lfs;
lfs_format(&lfs, cfg) => 0;
struct lfs_config cfg_ = *cfg;
if (INFER_BC) {
cfg_.block_count = 0;
}

for (int c = 0; c < CYCLES; c++) {
lfs_mount(&lfs, cfg) => 0;
lfs_mount(&lfs, &cfg_) => 0;
lfs_mkdir(&lfs, "breakfast") => 0;
lfs_unmount(&lfs) => 0;

for (int n = 0; n < FILES; n++) {
lfs_mount(&lfs, cfg) => 0;
lfs_mount(&lfs, &cfg_) => 0;
char path[1024];
sprintf(path, "breakfast/%s", names[n]);
lfs_file_t file;
Expand Down Expand Up @@ -232,10 +252,15 @@ code = '''

# exhaustion test
[cases.test_alloc_exhaustion]
defines.INFER_BC = [false, true]
code = '''
lfs_t lfs;
lfs_format(&lfs, cfg) => 0;
lfs_mount(&lfs, cfg) => 0;
struct lfs_config cfg_ = *cfg;
if (INFER_BC) {
cfg_.block_count = 0;
}
lfs_mount(&lfs, &cfg_) => 0;
lfs_file_t file;
lfs_file_open(&lfs, &file, "exhaustion", LFS_O_WRONLY | LFS_O_CREAT);
size_t size = strlen("exhaustion");
Expand Down Expand Up @@ -263,7 +288,7 @@ code = '''
lfs_file_close(&lfs, &file) => 0;
lfs_unmount(&lfs) => 0;

lfs_mount(&lfs, cfg) => 0;
lfs_mount(&lfs, &cfg_) => 0;
lfs_file_open(&lfs, &file, "exhaustion", LFS_O_RDONLY);
size = strlen("exhaustion");
lfs_file_size(&lfs, &file) => size;
Expand All @@ -276,10 +301,15 @@ code = '''
# exhaustion wraparound test
[cases.test_alloc_exhaustion_wraparound]
defines.SIZE = '(((BLOCK_SIZE-8)*(BLOCK_COUNT-4)) / 3)'
defines.INFER_BC = [false, true]
code = '''
lfs_t lfs;
lfs_format(&lfs, cfg) => 0;
lfs_mount(&lfs, cfg) => 0;
struct lfs_config cfg_ = *cfg;
if (INFER_BC) {
cfg_.block_count = 0;
}
lfs_mount(&lfs, &cfg_) => 0;

lfs_file_t file;
lfs_file_open(&lfs, &file, "padding", LFS_O_WRONLY | LFS_O_CREAT);
Expand Down Expand Up @@ -317,7 +347,7 @@ code = '''
lfs_file_close(&lfs, &file) => 0;
lfs_unmount(&lfs) => 0;

lfs_mount(&lfs, cfg) => 0;
lfs_mount(&lfs, &cfg_) => 0;
lfs_file_open(&lfs, &file, "exhaustion", LFS_O_RDONLY);
size = strlen("exhaustion");
lfs_file_size(&lfs, &file) => size;
Expand All @@ -330,10 +360,15 @@ code = '''

# dir exhaustion test
[cases.test_alloc_dir_exhaustion]
defines.INFER_BC = [false, true]
code = '''
lfs_t lfs;
lfs_format(&lfs, cfg) => 0;
lfs_mount(&lfs, cfg) => 0;
struct lfs_config cfg_ = *cfg;
if (INFER_BC) {
cfg_.block_count = 0;
}
lfs_mount(&lfs, &cfg_) => 0;

// find out max file size
lfs_mkdir(&lfs, "exhaustiondir") => 0;
Expand Down

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