/**
* Erases all the specified areas and initializes them with a clean nffs
* file system.
*
* @param area_descs The set of areas to format.
*
* @return 0 on success;
* nonzero on failure.
*/
int
nffs_format_full(const struct nffs_area_desc *area_descs)
{
int rc;
int i;
/* Start from a clean state. */
nffs_misc_reset();
/* Select largest area to be the initial scratch area. */
nffs_scratch_area_idx = 0;
for (i = 1; area_descs[i].nad_length != 0; i++) {
if (i >= NFFS_MAX_AREAS) {
rc = FS_EINVAL;
goto err;
}
if (area_descs[i].nad_length >
area_descs[nffs_scratch_area_idx].nad_length) {
nffs_scratch_area_idx = i;
}
}
rc = nffs_misc_set_num_areas(i);
if (rc != 0) {
goto err;
}
for (i = 0; i < nffs_num_areas; i++) {
nffs_areas[i].na_offset = area_descs[i].nad_offset;
nffs_areas[i].na_length = area_descs[i].nad_length;
nffs_areas[i].na_flash_id = area_descs[i].nad_flash_id;
nffs_areas[i].na_cur = 0;
nffs_areas[i].na_gc_seq = 0;
if (i == nffs_scratch_area_idx) {
nffs_areas[i].na_id = NFFS_AREA_ID_NONE;
} else {
nffs_areas[i].na_id = i;
}
rc = nffs_format_area(i, i == nffs_scratch_area_idx);
if (rc != 0) {
goto err;
}
}
rc = nffs_misc_validate_scratch();
if (rc != 0) {
goto err;
}
/* Create root directory. */
rc = nffs_file_new(NULL, "", 0, 1, &nffs_root_dir);
if (rc != 0) {
goto err;
}
/* Create "lost+found" directory. */
rc = nffs_misc_create_lost_found_dir();
if (rc != 0) {
goto err;
}
rc = nffs_misc_validate_root_dir();
if (rc != 0) {
goto err;
}
rc = nffs_misc_set_max_block_data_len(0);
if (rc != 0) {
goto err;
}
return 0;
err:
nffs_misc_reset();
return rc;
}
/**
* Searches for a valid nffs file system among the specified areas. This
* function succeeds if a file system is detected among any subset of the
* supplied areas. If the area set does not contain a valid file system,
* a new one can be created via a call to nffs_format().
*
* @param area_descs The area set to search. This array must be
* terminated with a 0-length area.
*
* @return 0 on success;
* FS_ECORRUPT if no valid file system was detected;
* other nonzero on error.
*/
int
nffs_restore_full(const struct nffs_area_desc *area_descs)
{
struct nffs_disk_area disk_area;
int cur_area_idx;
int use_area;
int rc;
int i;
/* Start from a clean state. */
rc = nffs_misc_reset();
if (rc) {
return rc;
}
nffs_restore_largest_block_data_len = 0;
/* Read each area from flash. */
for (i = 0; area_descs[i].nad_length != 0; i++) {
if (i > NFFS_MAX_AREAS) {
rc = FS_EINVAL;
goto err;
}
rc = nffs_restore_detect_one_area(area_descs[i].nad_flash_id,
area_descs[i].nad_offset,
&disk_area);
switch (rc) {
case 0:
use_area = 1;
break;
case FS_ECORRUPT:
use_area = 0;
break;
default:
goto err;
}
if (use_area) {
if (disk_area.nda_id == NFFS_AREA_ID_NONE &&
nffs_scratch_area_idx != NFFS_AREA_ID_NONE) {
/* Don't allow more than one scratch area. */
use_area = 0;
}
}
if (use_area) {
/* Populate RAM with a representation of this area. */
cur_area_idx = nffs_num_areas;
rc = nffs_misc_set_num_areas(nffs_num_areas + 1);
if (rc != 0) {
goto err;
}
nffs_areas[cur_area_idx].na_offset = area_descs[i].nad_offset;
nffs_areas[cur_area_idx].na_length = area_descs[i].nad_length;
nffs_areas[cur_area_idx].na_flash_id = area_descs[i].nad_flash_id;
nffs_areas[cur_area_idx].na_gc_seq = disk_area.nda_gc_seq;
nffs_areas[cur_area_idx].na_id = disk_area.nda_id;
if (disk_area.nda_id == NFFS_AREA_ID_NONE) {
nffs_areas[cur_area_idx].na_cur = NFFS_AREA_OFFSET_ID;
nffs_scratch_area_idx = cur_area_idx;
} else {
nffs_areas[cur_area_idx].na_cur =
sizeof (struct nffs_disk_area);
nffs_restore_area_contents(cur_area_idx);
}
}
}
/* All areas have been restored from flash. */
if (nffs_scratch_area_idx == NFFS_AREA_ID_NONE) {
/* No scratch area. The system may have been rebooted in the middle of
* a garbage collection cycle. Look for a candidate scratch area.
*/
rc = nffs_restore_corrupt_scratch();
if (rc != 0) {
if (rc == FS_ENOENT) {
rc = FS_ECORRUPT;
}
goto err;
}
}
/* Ensure this file system contains a valid scratch area. */
rc = nffs_misc_validate_scratch();
if (rc != 0) {
goto err;
}
/* Make sure the file system contains a valid root directory. */
rc = nffs_misc_validate_root_dir();
if (rc != 0) {
goto err;
}
/* Ensure there is a "/lost+found" directory. */
rc = nffs_misc_create_lost_found_dir();
if (rc != 0) {
goto err;
}
/* Delete from RAM any objects that were invalidated when subsequent areas
* were restored.
*/
nffs_restore_sweep();
/* Set the maximum data block size according to the size of the smallest
* area.
*/
rc = nffs_misc_set_max_block_data_len(nffs_restore_largest_block_data_len);
if (rc != 0) {
goto err;
}
return 0;
err:
nffs_misc_reset();
return rc;
}