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Added more seek tests, fixed some annoying POSIX/etc subtleties

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What do you think a file's size becomes when you:

1. seek past the end of a file
2. call write with zero data!

POSIX/etc has this case explicitly mentioned, noting that zero-sized
writes should never update the file size.

This clashes with the assumption that file writes always update the file
position, but I suppose it makes a bit of practical sense if you want
zero-sized file writes to be idempotent.
This commit is contained in:
Christopher Haster
2023-09-28 12:45:32 -05:00
parent 0638b09d18
commit 981e64f524
2 changed files with 453 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lfs.c
+13 -1
View File
@@ -8585,7 +8585,9 @@ lfs_ssize_t lfsr_file_read(lfs_t *lfs, lfsr_file_t *file,
void *buffer, lfs_size_t size) {
LFS_ASSERT(lfsr_file_isreadable(file));
lfs_ssize_t d = lfs_min32(size, file->size - file->pos);
lfs_ssize_t d = lfs_min32(
size,
file->size - lfs_min32(file->pos, file->size));
int err = lfsr_file_read_(lfs, file, file->pos, buffer, d);
if (err < 0) {
return err;
@@ -8765,12 +8767,22 @@ lfs_ssize_t lfsr_file_write(lfs_t *lfs, lfsr_file_t *file,
LFS_ASSERT(lfsr_file_iswriteable(file));
LFS_ASSERT(size <= 0x7fffffff);
// size=0 is a bit special and is gauranteed to have no effects on the
// underlying file, this means no updating file pos or file size
//
// since we need to test for this, just return early
if (size == 0) {
return 0;
}
// update pos if we are appending
// TODO wait, what does POSIX do here if we've seeked past the eof?
if (lfsr_file_isappend(file) && file->pos < file->size) {
file->pos = file->size;
}
// TODO do we need to prepare mutation?
lfs_off_t pos = file->pos;
const uint8_t *buffer_ = buffer;
int err;
tests/test_files.toml
+440 -4
View File
@@ -1163,10 +1163,10 @@ code = '''
lfsr_format(&lfs, CFG) => 0;
lfsr_mount(&lfs, CFG) => 0;
// create a file, truncating in case of powerloss
// create a file
lfsr_file_t file;
lfsr_file_open(&lfs, &file, "hello",
LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
// simulate our file in ram
uint8_t sim[SIZE];
lfs_off_t size;
@@ -1283,10 +1283,10 @@ code = '''
lfsr_format(&lfs, CFG) => 0;
lfsr_mount(&lfs, CFG) => 0;
// create a file, truncating in case of powerloss
// create a file
lfsr_file_t file;
lfsr_file_open(&lfs, &file, "hello",
LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
// simulate our file in ram
uint8_t sim[SIZE];
lfs_off_t size;
@@ -1395,6 +1395,442 @@ code = '''
'''
# more seek testing
[cases.test_files_r_seek]
defines.N = 100
defines.SEED = 'range(10)'
defines.WHENCE = ['LFS_SEEK_SET', 'LFS_SEEK_CUR', 'LFS_SEEK_END']
defines.SIZE = ['CACHE_SIZE/2', '2*CACHE_SIZE']
# chunk is more an upper limit here
defines.CHUNK = ['CACHE_SIZE/2', '4']
code = '''
lfs_t lfs;
lfsr_format(&lfs, CFG) => 0;
lfsr_mount(&lfs, CFG) => 0;
// create a file
lfsr_file_t file;
lfsr_file_open(&lfs, &file, "hello",
LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
// simulate our file in ram
uint8_t sim[SIZE];
uint32_t prng = SEED;
for (lfs_size_t i = 0; i < SIZE; i++) {
sim[i] = 'a' + (TEST_PRNG(&prng) % 26);
}
lfsr_file_write(&lfs, &file, sim, SIZE) => SIZE;
lfsr_file_close(&lfs, &file) => 0;
lfsr_file_open(&lfs, &file, "hello", LFS_O_RDONLY) => 0;
lfs_soff_t off_ = 0;
for (lfs_size_t i = 0; i < N; i++) {
// choose a random location
lfs_soff_t off = TEST_PRNG(&prng) % SIZE;
// and a random size, up to the chunk size
lfs_size_t chunk = lfs_min32(
TEST_PRNG(&prng) % CHUNK,
SIZE - off);
// test different seek methods
if (WHENCE == LFS_SEEK_SET) {
lfsr_file_seek(&lfs, &file, off, LFS_SEEK_SET) => off;
} else if (WHENCE == LFS_SEEK_CUR) {
lfsr_file_seek(&lfs, &file, off-off_, LFS_SEEK_CUR) => off;
} else if (WHENCE == LFS_SEEK_END) {
lfsr_file_seek(&lfs, &file, off-SIZE, LFS_SEEK_END) => off;
}
// tell should always report the correct position
lfsr_file_tell(&lfs, &file) => off;
// read the file and assert we got the correct data
uint8_t rbuf[2*SIZE];
memset(rbuf, 0xaa, 2*SIZE);
lfsr_file_read(&lfs, &file, rbuf, chunk) => chunk;
assert(memcmp(rbuf, &sim[off], chunk) == 0);
// tell should report the new position
lfsr_file_tell(&lfs, &file) => off + chunk;
// keep track of previous off for LFS_SEEK_CUR
off_ = off + chunk;
}
lfsr_file_close(&lfs, &file) => 0;
lfsr_unmount(&lfs) => 0;
'''
# this is pretty much the same as earlier fuzz testing, except we test
# different seek methods
[cases.test_files_w_seek]
defines.N = 100
defines.SEED = 'range(10)'
defines.WHENCE = ['LFS_SEEK_SET', 'LFS_SEEK_CUR', 'LFS_SEEK_END']
defines.SIZE = ['CACHE_SIZE/2', '2*CACHE_SIZE']
# chunk is more an upper limit here
defines.CHUNK = ['CACHE_SIZE/2', '4']
defines.INIT = [false, true]
defines.SYNC = [false, true]
code = '''
lfs_t lfs;
lfsr_format(&lfs, CFG) => 0;
lfsr_mount(&lfs, CFG) => 0;
// create a file
lfsr_file_t file;
lfsr_file_open(&lfs, &file, "hello",
LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
// simulate our file in ram
uint8_t sim[SIZE];
lfs_off_t size;
uint32_t prng = SEED;
if (INIT) {
for (lfs_size_t i = 0; i < SIZE; i++) {
sim[i] = 'a' + (TEST_PRNG(&prng) % 26);
}
lfsr_file_write(&lfs, &file, sim, SIZE) => SIZE;
size = SIZE;
} else {
memset(sim, 0, SIZE);
size = 0;
}
lfsr_file_close(&lfs, &file) => 0;
lfsr_file_open(&lfs, &file, "hello", LFS_O_WRONLY) => 0;
lfs_soff_t off_ = 0;
for (lfs_size_t i = 0; i < N; i++) {
// choose a random location
lfs_off_t off = TEST_PRNG(&prng) % SIZE;
// and a random size, up to the chunk size
lfs_size_t chunk = lfs_min32(
TEST_PRNG(&prng) % CHUNK,
SIZE - off);
// test different seek methods
if (WHENCE == LFS_SEEK_SET) {
lfsr_file_seek(&lfs, &file, off, LFS_SEEK_SET) => off;
} else if (WHENCE == LFS_SEEK_CUR) {
lfsr_file_seek(&lfs, &file, off-off_, LFS_SEEK_CUR) => off;
} else if (WHENCE == LFS_SEEK_END) {
lfsr_file_seek(&lfs, &file, off-size, LFS_SEEK_END) => off;
}
// tell should always report the correct position
lfsr_file_tell(&lfs, &file) => off;
// update the sim
for (lfs_size_t j = 0; j < chunk; j++) {
sim[off+j] = 'a' + (TEST_PRNG(&prng) % 26);
}
if (chunk != 0) {
size = lfs_max32(size, off+chunk);
}
// update the file
lfsr_file_write(&lfs, &file, &sim[off], chunk) => chunk;
// sync?
if (SYNC) {
lfsr_file_sync(&lfs, &file) => 0;
}
// tell should report the new position
lfsr_file_tell(&lfs, &file) => off + chunk;
// keep track of previous off for LFS_SEEK_CUR
off_ = off + chunk;
}
lfsr_file_close(&lfs, &file) => 0;
// check our file with stat
struct lfs_info info;
lfsr_stat(&lfs, "hello", &info) => 0;
assert(strcmp(info.name, "hello") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == size);
// and with dir read
lfsr_dir_t dir;
lfsr_dir_open(&lfs, &dir, "/") => 0;
lfsr_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfsr_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfsr_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, "hello") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == size);
lfsr_dir_read(&lfs, &dir, &info) => LFS_ERR_NOENT;
lfsr_dir_close(&lfs, &dir) => 0;
// try reading our file
lfsr_file_open(&lfs, &file, "hello", LFS_O_RDONLY) => 0;
// is size correct?
lfsr_file_size(&lfs, &file) => size;
// try reading
uint8_t rbuf[2*SIZE];
memset(rbuf, 0xaa, 2*SIZE);
lfsr_file_read(&lfs, &file, rbuf, 2*SIZE) => size;
// does our file match our simulation?
assert(memcmp(rbuf, sim, size) == 0);
lfsr_file_close(&lfs, &file) => 0;
lfsr_unmount(&lfs) => 0;
'''
# the above was just warmup, here's the real seek test
[cases.test_files_rw_seek]
defines.N = 100
defines.SEED = 'range(100)'
defines.WHENCE = ['LFS_SEEK_SET', 'LFS_SEEK_CUR', 'LFS_SEEK_END']
defines.SIZE = ['CACHE_SIZE/2', '2*CACHE_SIZE']
# chunk is more an upper limit here
defines.CHUNK = ['CACHE_SIZE/2', '4']
defines.INIT = [false, true]
defines.SYNC = [false, true]
code = '''
lfs_t lfs;
lfsr_format(&lfs, CFG) => 0;
lfsr_mount(&lfs, CFG) => 0;
// create a file
lfsr_file_t file;
lfsr_file_open(&lfs, &file, "hello",
LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
// simulate our file in ram
uint8_t sim[SIZE];
lfs_off_t size;
uint32_t prng = SEED;
if (INIT) {
for (lfs_size_t i = 0; i < SIZE; i++) {
sim[i] = 'a' + (TEST_PRNG(&prng) % 26);
}
lfsr_file_write(&lfs, &file, sim, SIZE) => SIZE;
size = SIZE;
} else {
memset(sim, 0, SIZE);
size = 0;
}
lfsr_file_close(&lfs, &file) => 0;
lfsr_file_open(&lfs, &file, "hello", LFS_O_RDWR) => 0;
lfs_soff_t off_ = 0;
for (lfs_size_t i = 0; i < N; i++) {
// choose a random location
lfs_off_t off = TEST_PRNG(&prng) % SIZE;
// and a random size, up to the chunk size
lfs_size_t chunk = lfs_min32(
TEST_PRNG(&prng) % CHUNK,
SIZE - off);
// and if we are reading or writing
uint8_t op = TEST_PRNG(&prng) % 2;
// test different seek methods
if (WHENCE == LFS_SEEK_SET) {
lfsr_file_seek(&lfs, &file, off, LFS_SEEK_SET) => off;
} else if (WHENCE == LFS_SEEK_CUR) {
lfsr_file_seek(&lfs, &file, off-off_, LFS_SEEK_CUR) => off;
} else if (WHENCE == LFS_SEEK_END) {
lfsr_file_seek(&lfs, &file, off-size, LFS_SEEK_END) => off;
}
// tell should always report the correct position
lfsr_file_tell(&lfs, &file) => off;
// writing?
if (op == 0) {
// update the sim
for (lfs_size_t j = 0; j < chunk; j++) {
sim[off+j] = 'a' + (TEST_PRNG(&prng) % 26);
}
if (chunk != 0) {
size = lfs_max32(size, off+chunk);
}
// update the file
lfsr_file_write(&lfs, &file, &sim[off], chunk) => chunk;
// sync?
if (SYNC) {
lfsr_file_sync(&lfs, &file) => 0;
}
// tell should report the new position
lfsr_file_tell(&lfs, &file) => off + chunk;
// keep track of previous off for LFS_SEEK_CUR
off_ = off + chunk;
// reading?
} else if (op == 1) {
// we may read less than chunk if we're past eof
lfs_off_t expected = lfs_min32(
chunk,
size - lfs_min32(off, size));
// read the file and assert we got the correct data
uint8_t rbuf[2*SIZE];
memset(rbuf, 0xaa, 2*SIZE);
lfsr_file_read(&lfs, &file, rbuf, chunk) => expected;
assert(memcmp(rbuf, &sim[off], expected) == 0);
// tell should report the new position
lfsr_file_tell(&lfs, &file) => off + expected;
// keep track of previous off for LFS_SEEK_CUR
off_ = off + expected;
}
}
lfsr_file_close(&lfs, &file) => 0;
// check our file with stat
struct lfs_info info;
lfsr_stat(&lfs, "hello", &info) => 0;
assert(strcmp(info.name, "hello") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == size);
// and with dir read
lfsr_dir_t dir;
lfsr_dir_open(&lfs, &dir, "/") => 0;
lfsr_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfsr_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfsr_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, "hello") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == size);
lfsr_dir_read(&lfs, &dir, &info) => LFS_ERR_NOENT;
lfsr_dir_close(&lfs, &dir) => 0;
// try reading our file
lfsr_file_open(&lfs, &file, "hello", LFS_O_RDONLY) => 0;
// is size correct?
lfsr_file_size(&lfs, &file) => size;
// try reading
uint8_t rbuf[2*SIZE];
memset(rbuf, 0xaa, 2*SIZE);
lfsr_file_read(&lfs, &file, rbuf, 2*SIZE) => size;
// does our file match our simulation?
assert(memcmp(rbuf, sim, size) == 0);
lfsr_file_close(&lfs, &file) => 0;
lfsr_unmount(&lfs) => 0;
'''
# test other corner conditions
[cases.test_files_seek_negative]
defines.WHENCE = ['LFS_SEEK_SET', 'LFS_SEEK_CUR', 'LFS_SEEK_END']
defines.SIZE = ['CACHE_SIZE/2', '2*CACHE_SIZE']
defines.INIT = [false, true]
defines.MODE = ['LFS_O_RDONLY', 'LFS_O_WRONLY', 'LFS_O_RDWR']
code = '''
lfs_t lfs;
lfsr_format(&lfs, CFG) => 0;
lfsr_mount(&lfs, CFG) => 0;
// create a file
lfsr_file_t file;
lfsr_file_open(&lfs, &file, "hello",
LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
// simulate our file in ram
uint8_t sim[SIZE];
lfs_off_t size;
uint32_t prng = 42;
if (INIT) {
for (lfs_size_t i = 0; i < SIZE; i++) {
sim[i] = 'a' + (TEST_PRNG(&prng) % 26);
}
lfsr_file_write(&lfs, &file, sim, SIZE) => SIZE;
size = SIZE;
} else {
memset(sim, 0, SIZE);
size = 0;
}
lfsr_file_close(&lfs, &file) => 0;
// try to seek before the beginning of the file, this should fail
lfsr_file_open(&lfs, &file, "hello", MODE) => 0;
if (WHENCE == LFS_SEEK_SET) {
lfsr_file_seek(&lfs, &file, -1, LFS_SEEK_SET) => LFS_ERR_INVAL;
} else if (WHENCE == LFS_SEEK_CUR) {
lfsr_file_seek(&lfs, &file, -1, LFS_SEEK_CUR) => LFS_ERR_INVAL;
} else if (WHENCE == LFS_SEEK_END) {
lfsr_file_seek(&lfs, &file, -(size+1), LFS_SEEK_END) => LFS_ERR_INVAL;
}
lfsr_file_close(&lfs, &file) => 0;
// check our file with stat
struct lfs_info info;
lfsr_stat(&lfs, "hello", &info) => 0;
assert(strcmp(info.name, "hello") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == size);
// and with dir read
lfsr_dir_t dir;
lfsr_dir_open(&lfs, &dir, "/") => 0;
lfsr_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfsr_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfsr_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, "hello") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == size);
lfsr_dir_read(&lfs, &dir, &info) => LFS_ERR_NOENT;
lfsr_dir_close(&lfs, &dir) => 0;
// try reading our file
lfsr_file_open(&lfs, &file, "hello", LFS_O_RDONLY) => 0;
// is size correct?
lfsr_file_size(&lfs, &file) => size;
// try reading
uint8_t rbuf[2*SIZE];
memset(rbuf, 0xaa, 2*SIZE);
lfsr_file_read(&lfs, &file, rbuf, 2*SIZE) => size;
// does our file match our simulation?
assert(memcmp(rbuf, sim, size) == 0);
lfsr_file_close(&lfs, &file) => 0;
lfsr_unmount(&lfs) => 0;
'''
# TODO
# [cases.test_files_truncate] ?
# [cases.test_files_fruncate] ?
# [cases.test_files_no_hidden_data]
# [cases.test_files_rwtf_fuzz] ?
# [cases.test_files_push] ?
# [cases.test_files_pop] ?
# [cases.test_files_rwtfpp_fuzz] ?
# [cases.test_files_rm]
# [cases.test_files_mv]
# [cases.test_files_mvrm]
# [cases.test_files_rmed]
# [cases.test_files_mved]
# [cases.test_files_mvrmed]
# [cases.test_files_multi_readers]
# [cases.test_files_multi_readers_one_writer]
# [cases.test_files_multi_writers]
# [cases.test_files_multi_readers_multi_writers]
# [cases.test_files_many]
# [cases.test_files_interleaved]
# [cases.test_files_interleaved_fuzz]
# [cases.test_files_interleaved_fuzz_fuzz]
# [cases.test_files_dtree_fuzz]
# [cases.test_files_dtree_fuzz_fuzz]