AP_FlashStorage: fixed a race condition

fixes #7670

thanks to night-ghost for the bug report
This commit is contained in:
Andrew Tridgell 2019-01-21 15:50:24 +11:00
parent 751dade9a8
commit 91e5f56242
2 changed files with 9 additions and 4 deletions

View File

@ -111,7 +111,12 @@ bool AP_FlashStorage::init(void)
// if the first sector is full then write out all data so we can erase it
if (states[first_sector] == SECTOR_STATE_FULL) {
current_sector = first_sector ^ 1;
if (!write_all()) {
// we start by writing all except the sector header
if (!write_all(sizeof(sector_header))) {
return erase_all();
}
// now write the header
if (!write(0, sizeof(sector_header))) {
return erase_all();
}
}
@ -309,11 +314,11 @@ bool AP_FlashStorage::erase_all(void)
/*
write all of mem_buffer to current sector
*/
bool AP_FlashStorage::write_all(void)
bool AP_FlashStorage::write_all(uint16_t start_ofs)
{
debug("write_all to sector %u at %u with reserved_space=%u\n",
current_sector, write_offset, reserved_space);
for (uint16_t ofs=0; ofs<storage_size; ofs += max_write) {
for (uint16_t ofs=start_ofs; ofs<storage_size; ofs += max_write) {
if (!all_zero(ofs, max_write)) {
if (!write(ofs, max_write)) {
return false;

View File

@ -141,7 +141,7 @@ private:
bool erase_all();
// write all of mem_buffer to current sector
bool write_all(void);
bool write_all(uint16_t start_ofs=0);
// return true if all bytes are zero
bool all_zero(uint16_t ofs, uint16_t size);