littlefs: Fixed file truncation without writes

In the open call, the LFS_O_TRUNC flag was correctly zeroing the file, but
it wasn't actually writing the change out to disk. This went unnoticed because
in the cases where the truncate was followed by a file write, the
updated contents would be written out correctly.

Marking the file as dirty if the file isn't already truncated fixes the
problem with the least impact. Also added better test cases around
truncating files.
pull/5832/head
Christopher Haster 2018-01-11 16:27:33 -06:00
parent dc87f0b1e6
commit 5df2b9b0e7
2 changed files with 30 additions and 2 deletions

View File

@ -1261,6 +1261,9 @@ int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
file->pos = 0;
if (flags & LFS_O_TRUNC) {
if (file->size != 0) {
file->flags |= LFS_F_DIRTY;
}
file->head = 0xffffffff;
file->size = 0;
}

View File

@ -34,7 +34,8 @@ tests/test.py << TEST
lfs_size_t chunk = 31;
srand(0);
lfs_mount(&lfs, &cfg) => 0;
lfs_file_open(&lfs, &file[0], "$2", LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_open(&lfs, &file[0], "$2",
${3:-LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC}) => 0;
for (lfs_size_t i = 0; i < size; i += chunk) {
chunk = (chunk < size - i) ? chunk : size - i;
for (lfs_size_t b = 0; b < chunk; b++) {
@ -53,7 +54,10 @@ tests/test.py << TEST
lfs_size_t chunk = 29;
srand(0);
lfs_mount(&lfs, &cfg) => 0;
lfs_file_open(&lfs, &file[0], "$2", LFS_O_RDONLY) => 0;
lfs_stat(&lfs, "$2", &info) => 0;
info.type => LFS_TYPE_REG;
info.size => size;
lfs_file_open(&lfs, &file[0], "$2", ${3:-LFS_O_RDONLY}) => 0;
for (lfs_size_t i = 0; i < size; i += chunk) {
chunk = (chunk < size - i) ? chunk : size - i;
lfs_file_read(&lfs, &file[0], buffer, chunk) => chunk;
@ -78,10 +82,27 @@ echo "--- Large file test ---"
w_test $LARGESIZE largeavacado
r_test $LARGESIZE largeavacado
echo "--- Zero file test ---"
w_test 0 noavacado
r_test 0 noavacado
echo "--- Truncate small test ---"
w_test $SMALLSIZE mediumavacado
r_test $SMALLSIZE mediumavacado
w_test $MEDIUMSIZE mediumavacado
r_test $MEDIUMSIZE mediumavacado
echo "--- Truncate zero test ---"
w_test $SMALLSIZE noavacado
r_test $SMALLSIZE noavacado
w_test 0 noavacado
r_test 0 noavacado
echo "--- Non-overlap check ---"
r_test $SMALLSIZE smallavacado
r_test $MEDIUMSIZE mediumavacado
r_test $LARGESIZE largeavacado
r_test 0 noavacado
echo "--- Dir check ---"
tests/test.py << TEST
@ -105,6 +126,10 @@ tests/test.py << TEST
strcmp(info.name, "largeavacado") => 0;
info.type => LFS_TYPE_REG;
info.size => $LARGESIZE;
lfs_dir_read(&lfs, &dir[0], &info) => 1;
strcmp(info.name, "noavacado") => 0;
info.type => LFS_TYPE_REG;
info.size => 0;
lfs_dir_read(&lfs, &dir[0], &info) => 0;
lfs_dir_close(&lfs, &dir[0]) => 0;
lfs_unmount(&lfs) => 0;