fix(uavcan): close directory before processing files in migrateFWFromRoot (#26676)

migrateFWFromRoot held the SD root directory open via opendir/readdir
while performing heavy file I/O (getFileInfo, copyFw, unlink) inside the
loop. Between readdir calls the FAT semaphore is released, allowing
other tasks (e.g. logger) to dirty the shared FAT sector cache. When
the next FAT operation needed a different sector, fat_fscacheflush
would write the dirty data followed by an immediate read — triggering
a write-busy to read transition in the SDMMC WRCOMPLETE path that
kills the SD card on STM32H7.

Split into two phases: first collect .bin filenames with the directory
open, then close it before doing any file I/O. This also fixes a
missing closedir on the mkdir error path and avoids modifying directory
entries (via unlink) while iterating them with readdir.
This commit is contained in:
Jacob Dahl
2026-03-06 10:32:57 -09:00
committed by GitHub
parent 4429c53f93
commit 26969c25ff

View File

@@ -157,14 +157,8 @@ void UavcanServers::migrateFWFromRoot(const char *sd_path, const char *sd_root_p
const size_t sd_root_path_len = strlen(sd_root_path);
struct stat sb;
int rv;
char dstpath[maxlen + 1];
char srcpath[maxlen + 1];
DIR *const sd_root_dir = opendir(sd_root_path);
if (!sd_root_dir) {
return;
}
char dstpath[maxlen + 1];
if (stat(sd_path, &sb) != 0 || !S_ISDIR(sb.st_mode)) {
rv = mkdir(sd_path, S_IRWXU | S_IRWXG | S_IRWXO);
@@ -175,19 +169,21 @@ void UavcanServers::migrateFWFromRoot(const char *sd_path, const char *sd_root_p
}
}
// Iterate over all bin files in root directory
// Phase 1: collect .bin filenames with directory open, then close
static constexpr int MaxBinFiles = 10;
char bin_names[MaxBinFiles][NAME_MAX + 1];
int bin_count = 0;
DIR *const sd_root_dir = opendir(sd_root_path);
if (!sd_root_dir) {
return;
}
struct dirent *dev_dirent = NULL;
while ((dev_dirent = readdir(sd_root_dir)) != nullptr) {
uavcan_posix::FirmwareVersionChecker::AppDescriptor descriptor{0};
// Looking for all uavcan.bin files.
while ((dev_dirent = readdir(sd_root_dir)) != nullptr && bin_count < MaxBinFiles) {
if (DIRENT_ISFILE(dev_dirent->d_type) && strstr(dev_dirent->d_name, ".bin") != nullptr) {
// Make sure the path fits
size_t filename_len = strlen(dev_dirent->d_name);
size_t srcpath_len = sd_root_path_len + 1 + filename_len;
@@ -196,26 +192,33 @@ void UavcanServers::migrateFWFromRoot(const char *sd_path, const char *sd_root_p
continue;
}
snprintf(srcpath, sizeof(srcpath), "%s%s", sd_root_path, dev_dirent->d_name);
if (uavcan_posix::FirmwareVersionChecker::getFileInfo(srcpath, descriptor, 1024) != 0) {
continue;
}
if (descriptor.image_crc == 0) {
continue;
}
snprintf(dstpath, sizeof(dstpath), "%s/%d.bin", sd_path, descriptor.board_id);
if (copyFw(dstpath, srcpath) >= 0) {
unlink(srcpath);
}
strncpy(bin_names[bin_count], dev_dirent->d_name, NAME_MAX);
bin_names[bin_count][NAME_MAX] = '\0';
bin_count++;
}
}
if (sd_root_dir != nullptr) {
(void)closedir(sd_root_dir);
(void)closedir(sd_root_dir);
// Phase 2: process collected files with directory closed
for (int i = 0; i < bin_count; i++) {
uavcan_posix::FirmwareVersionChecker::AppDescriptor descriptor{0};
snprintf(srcpath, sizeof(srcpath), "%s%s", sd_root_path, bin_names[i]);
if (uavcan_posix::FirmwareVersionChecker::getFileInfo(srcpath, descriptor, 1024) != 0) {
continue;
}
if (descriptor.image_crc == 0) {
continue;
}
snprintf(dstpath, sizeof(dstpath), "%s/%d.bin", sd_path, descriptor.board_id);
if (copyFw(dstpath, srcpath) >= 0) {
unlink(srcpath);
}
}
}