//
// To trancate the file, this is the last block to be trancated.
// We need to discard one or more pages within this block, hence requires 'block recover'.
//
static URET do_TruncateInternalWithBlockRecover(uffs_Object *obj,
u16 fdn, u32 remain, RunOptionE run_opt)
{
uffs_Device *dev = obj->dev;
TreeNode *fnode = obj->node;
u16 page_id, max_page_id;
TreeNode *node;
uffs_Buf *buf = NULL;
u8 type;
u32 block_start, block_offset;
u16 parent, serial;
int slot;
uffs_BlockInfo *bc = NULL;
int block = -1;
if (fdn == 0) {
node = fnode;
type = UFFS_TYPE_FILE;
max_page_id = obj->head_pages;
block_start = 0;
parent = node->u.file.parent;
serial = node->u.file.serial;
block = node->u.file.block;
}
else {
node = uffs_TreeFindDataNode(dev, fnode->u.file.serial, fdn);
if (node == NULL) {
obj->err = UEIOERR;
uffs_Perror(UFFS_MSG_SERIOUS,
"can't find data node when truncate obj");
goto ext;
}
block = node->u.data.block;
type = UFFS_TYPE_DATA;
max_page_id = dev->attr->pages_per_block - 1;
block_start = obj->head_pages * dev->com.pg_data_size +
(fdn - 1) * dev->com.pg_data_size *
dev->attr->pages_per_block;
parent = node->u.data.parent;
serial = node->u.data.serial;
}
if (run_opt == eDRY_RUN) {
// checking the buffer. this is the main reason why we need the 'dry run' mode.
for (page_id = 0; page_id <= max_page_id; page_id++) {
buf = uffs_BufFind(dev, parent, serial, page_id);
if (buf) {
//!< ok, the buffer was loaded before ...
if (uffs_BufIsFree(buf) == U_FALSE) {
obj->err = UEEXIST;
break; //!< and someone is still holding the buffer,
// can't truncate it !!!
}
}
}
buf = NULL;
goto ext;
}
// find the last page *after* truncate
block_offset = remain - block_start;
page_id = block_offset / dev->com.pg_data_size;
if (fdn == 0)
page_id++;
if (!uffs_Assert(page_id <= max_page_id, "fdn = %d, block_start = %d, remain = %d\n", fdn, block_start, remain)) {
obj->err = UEUNKNOWN_ERR;
goto ext;
}
// flush buffer before performing block recovery
uffs_BufFlushGroup(dev, parent, serial);
// load the last page
buf = uffs_BufGetEx(dev, type, node, page_id, obj->oflag);
if (buf == NULL) {
obj->err = UENOMEM;
uffs_Perror(UFFS_MSG_SERIOUS, "Can't get buf");
goto ext;
}
uffs_BufWrite(dev, buf, NULL, 0, 0); // just make this buf dirty
// lock the group
slot = uffs_BufFindGroupSlot(dev, parent, serial);
uffs_BufLockGroup(dev, slot);
if (remain == 0) // remain == 0: means discard all data in this block.
buf->data_len = 0;
else {
remain = (remain % dev->com.pg_data_size);
// remain == 0: means that we need to keep all data in this page.
buf->data_len = (remain == 0 ? dev->com.pg_data_size : remain);
}
/* mark this buf as UFFS_BUF_EXT_MARK_TRUNC_TAIL, when flushing
dirty buffers, UFFS will not do page recover for pages after
this buf page id (because this file is ended at this page) */
buf->ext_mark |= UFFS_BUF_EXT_MARK_TRUNC_TAIL;
uffs_BufPut(dev, buf);
// invalidate the rest page buf
page_id++;
for (; page_id <= max_page_id; page_id++) {
buf = uffs_BufFind(dev, parent, serial, page_id);
if (buf)
uffs_BufMarkEmpty(dev, buf);
}
// flush dirty buffer immediately, forcing block recovery.
uffs_BufFlushGroupEx(dev, parent, serial, U_TRUE);
// unlock the group
uffs_BufUnLockGroup(dev, slot);
// Invalidate block info cache for the 'old' block
bc = uffs_BlockInfoGet(dev, block);
if (bc) {
uffs_BlockInfoExpire(dev, bc, UFFS_ALL_PAGES);
uffs_BlockInfoPut(dev, bc);
}
ext:
return (obj->err == UENOERR ? U_SUCC : U_FAIL);
}
static URET do_TruncateInternalWithBlockRecover(uffs_Object *obj, u16 fdn, u32 remain, UBOOL dry_run)
{
uffs_Device *dev = obj->dev;
TreeNode *fnode = obj->node;
u16 page_id, max_page_id;
TreeNode *node;
uffs_Buf *buf = NULL;
u8 type;
u32 block_start;
u16 parent, serial;
int slot;
if (fdn == 0) {
node = fnode;
type = UFFS_TYPE_FILE;
max_page_id = obj->head_pages;
block_start = 0;
parent = node->u.file.parent;
serial = node->u.file.serial;
}
else {
node = uffs_TreeFindDataNode(dev, fnode->u.file.serial, fdn);
if (node == NULL) {
obj->err = UEIOERR;
uffs_Perror(UFFS_ERR_SERIOUS, "can't find data node when truncate obj");
goto ext;
}
type = UFFS_TYPE_DATA;
max_page_id = dev->attr->pages_per_block - 1;
block_start = obj->head_pages * dev->com.pg_data_size + (fdn - 1) * dev->com.pg_data_size * dev->attr->pages_per_block;
parent = node->u.data.parent;
serial = node->u.data.serial;
}
if (dry_run == U_TRUE) {
// checking the buffer. this is the main reason why we need the 'dry run' mode.
for (page_id = 0; page_id <= max_page_id; page_id++) {
buf = uffs_BufFind(dev, parent, serial, page_id);
if (buf) { //!< ok, the buffer was loaded before ...
if (uffs_BufIsFree(buf) == U_FALSE) {
obj->err = UEEXIST;
break; //!< and someone is still holding the buffer, can't truncate it !!!
}
}
}
buf = NULL;
goto ext;
}
// find the last page after truncate
for (page_id = (fdn == 0 ? 1 : 0); page_id <= max_page_id; page_id++) {
if (block_start + (page_id + 1) * dev->com.pg_data_size >= remain)
break;
}
if (page_id > max_page_id) {
obj->err = UEUNKNOWN;
uffs_Perror(UFFS_ERR_SERIOUS, "Overflow");
goto ext;
}
// flush buffer before performing block recovery
uffs_BufFlushGroup(dev, parent, serial);
// load the last page
buf = uffs_BufGetEx(dev, type, node, page_id);
if (buf == NULL) {
obj->err = UENOMEM;
uffs_Perror(UFFS_ERR_SERIOUS, "Can't get buf");
goto ext;
}
uffs_BufWrite(dev, buf, NULL, 0, 0); // just make this buf dirty
// lock the group
slot = uffs_BufFindGroupSlot(dev, parent, serial);
uffs_BufLockGroup(dev, slot);
if (remain == 0)
buf->data_len = 0;
else {
remain = (remain % dev->com.pg_data_size);
buf->data_len = (remain == 0 ? dev->com.pg_data_size : 0);
}
buf->ext_mark |= UFFS_BUF_EXT_MARK_TRUNC_TAIL;
uffs_BufPut(dev, buf);
// invalidate the rest page buf
page_id++;
for (; page_id <= max_page_id; page_id++) {
buf = uffs_BufFind(dev, parent, serial, page_id);
if (buf)
uffs_BufMarkEmpty(dev, buf);
}
// flush dirty buffer immediately, forcing block recovery.
uffs_BufFlushGroupEx(dev, parent, serial, U_TRUE);
// unlock the group
uffs_BufUnLockGroup(dev, slot);
ext:
return (obj->err == UENOERR ? U_SUCC : U_FAIL);
}
