/**
* find a node from tree
* \param[in] dev uffs device
* \param[in] type type of node
* \param[in] parent parent serial num
* \param[in] serial serial num
*/
TreeNode * uffs_FindFromTree(uffs_Device *dev,
u8 type, u16 parent, u16 serial)
{
switch (type) {
case UFFS_TYPE_DIR:
return uffs_TreeFindDirNode(dev, serial);
case UFFS_TYPE_FILE:
return uffs_TreeFindFileNode(dev, serial);
case UFFS_TYPE_DATA:
return uffs_TreeFindDataNode(dev, parent, serial);
}
uffs_Perror(UFFS_MSG_SERIOUS,
"unkown type, can't find node");
return NULL;
}
/**
* write data to obj, return remain data (0 if all data been written).
*/
static int do_WriteObject(uffs_Object *obj, const void *data, int len)
{
uffs_Device *dev = obj->dev;
TreeNode *fnode = obj->node;
int remain = len;
u16 fdn;
u32 write_start;
TreeNode *dnode;
u32 size;
while (remain > 0) {
write_start = obj->pos + len - remain;
if (write_start > fnode->u.file.len) {
uffs_Perror(UFFS_MSG_SERIOUS, "write point out of file ?");
break;
}
fdn = GetFdnByOfs(obj, write_start);
if (write_start == fnode->u.file.len && fdn > 0 &&
write_start == GetStartOfDataBlock(obj, fdn)) {
if (dev->tree.erased_count < dev->cfg.reserved_free_blocks) {
uffs_Perror(UFFS_MSG_NOISY, "insufficient block in write obj, new block");
break;
}
size = do_WriteNewBlock(obj, data ? (u8 *)data + len - remain : NULL,
remain, fnode->u.file.serial, fdn);
//
// Flush the new block buffers immediately, so that the new data node will be
// created and put in the tree.
//
// But before do that, we need to make sure the previous
// data block (if exist) been flushed first.
//
if (fdn > 1) {
uffs_BufFlushGroup(dev, fnode->u.file.serial, fdn - 1);
}
else {
uffs_BufFlushGroup(dev, fnode->u.file.parent, fnode->u.file.serial);
}
// Now flush the new block.
uffs_BufFlushGroup(dev, fnode->u.file.serial, fdn);
if (size == 0)
break;
remain -= size;
}
else {
if(fdn == 0)
dnode = obj->node;
else
dnode = uffs_TreeFindDataNode(dev, fnode->u.file.serial, fdn);
if(dnode == NULL) {
uffs_Perror(UFFS_MSG_SERIOUS, "can't find data node in tree ?");
obj->err = UEUNKNOWN_ERR;
break;
}
size = do_WriteInternalBlock(obj, dnode, fdn,
data ? (u8 *)data + len - remain : NULL, remain,
write_start - GetStartOfDataBlock(obj, fdn));
#ifdef CONFIG_FLUSH_BUF_AFTER_WRITE
if (fdn == 0)
uffs_BufFlushGroup(dev, fnode->u.file.parent, fnode->u.file.serial);
else
uffs_BufFlushGroup(dev, fnode->u.file.serial, fdn);
#endif
if (size == 0)
break;
remain -= size;
}
}
uffs_Assert(fnode == obj->node, "obj->node change!\n");
return remain;
}
/**
* \brief delete uffs object
*
* \param[in] name full name of object
* \param[out] err return error code
*
* \return U_SUCC if object is deleted successfully.
* return U_FAIL if error happen, error code is set to *err.
*/
URET uffs_DeleteObject(const char * name, int *err)
{
uffs_Object *obj, *work;
TreeNode *node, *d_node;
uffs_Device *dev = NULL;
u16 block;
u16 serial, parent, last_serial;
UBOOL bad = U_FALSE;
URET ret = U_FAIL;
obj = uffs_GetObject();
if (obj == NULL) {
if (err)
*err = UEMFILE;
goto ext_unlock;
}
if (uffs_OpenObject(obj, name, UO_RDWR|UO_DIR) == U_FAIL) {
if (uffs_OpenObject(obj, name, UO_RDWR) == U_FAIL) {
if (err)
*err = UENOENT;
goto ext_unlock;
}
}
dev = obj->dev;
// working throught object pool see if the object is opened ...
uffs_ObjectDevLock(obj);
work = NULL;
while ((work = (uffs_Object *)uffs_PoolFindNextAllocated(&_object_pool, work)) != NULL) {
if (work != obj &&
work->dev &&
work->dev == obj->dev &&
work->node &&
work->node == obj->node) {
// this object is opened, can't delete it.
if (err)
*err = UEACCES;
goto ext_lock;
}
}
if (obj->type == UFFS_TYPE_DIR) {
// if the dir is not empty, can't delete it.
node = uffs_TreeFindDirNodeWithParent(dev, obj->serial);
if (node != NULL) {
if (err)
*err = UEACCES;
goto ext_lock; //have sub dirs ?
}
node = uffs_TreeFindFileNodeWithParent(dev, obj->serial);
if (node != NULL) {
if (err)
*err = UEACCES;
goto ext_lock; //have sub files ?
}
}
// before erase the block, we need to take care of the buffer ...
uffs_BufFlushAll(dev);
if (_CheckObjBufRef(obj) > 0) {
if (err)
*err = UEACCES;
goto ext_lock;
}
node = obj->node;
// ok, now we are safe to erase DIR/FILE block :-)
block = GET_BLOCK_FROM_NODE(obj);
parent = obj->serial;
last_serial = (obj->type == UFFS_TYPE_FILE && node->u.file.len > 0 ? GetFdnByOfs(obj, node->u.file.len - 1) : 0);
uffs_BreakFromEntry(dev, obj->type, node);
uffs_FlashEraseBlock(dev, block);
node->u.list.block = block;
node->u.list.u.serial = obj->serial;
// From now on, the object is gone physically,
// but we need to 'suspend' this node so that no one will re-use
// the serial number during deleting the reset part of object.
if (HAVE_BADBLOCK(dev)) {
uffs_BadBlockProcessSuspend(dev, node);
bad = U_TRUE; // will be put into 'bad' list later
}
else {
uffs_TreeSuspendAdd(dev, node);
bad = U_FALSE; // will be put into erased list later
}
// now erase DATA blocks
if (obj->type == UFFS_TYPE_FILE && last_serial > 0) {
for (serial = 1; serial <= last_serial; serial++) {
uffs_ObjectDevUnLock(obj);
; // yield CPU to improve responsive when deleting large file.
uffs_ObjectDevLock(obj);
d_node = uffs_TreeFindDataNode(dev, parent, serial);
if (uffs_Assert(d_node != NULL, "Can't find DATA node parent = %d, serial = %d\n", parent, serial)) {
uffs_BreakFromEntry(dev, UFFS_TYPE_DATA, d_node);
block = d_node->u.data.block;
uffs_FlashEraseBlock(dev, block);
d_node->u.list.block = block;
if (HAVE_BADBLOCK(dev))
uffs_BadBlockProcess(dev, d_node);
else
uffs_TreeInsertToErasedListTail(dev, d_node);
}
}
}
// now process the suspend node
uffs_TreeRemoveSuspendNode(dev, node);
if (bad)
uffs_TreeInsertToBadBlockList(dev, node);
else
uffs_TreeInsertToErasedListTail(dev, node);
ret = U_SUCC;
ext_lock:
uffs_ObjectDevUnLock(obj);
ext_unlock:
do_ReleaseObjectResource(obj);
uffs_PutObject(obj);
return ret;
}
/** truncate obj without lock device */
static URET do_TruncateObject(uffs_Object *obj, u32 remain, RunOptionE run_opt)
{
uffs_Device *dev = obj->dev;
TreeNode *fnode = obj->node;
u16 fdn;
u32 flen;
u32 block_start;
TreeNode *node;
uffs_BlockInfo *bc;
uffs_Buf *buf;
u16 page;
int pos;
pos = obj->pos; // save current file position
if (obj->dev == NULL || obj->open_succ == U_FALSE || fnode == NULL) {
obj->err = UEBADF;
goto ext;
}
/* can't truncate a dir */
/* TODO: delete files under dir ? */
if (obj->type == UFFS_TYPE_DIR) {
obj->err = UEEXIST;
goto ext;
}
if (remain >= fnode->u.file.len) {
goto ext; //!< nothing to do ...
}
flen = fnode->u.file.len;
if (flen < remain) {
// file is shorter than 'reamin', fill the gap with '\0'
if (run_opt == eREAL_RUN) {
obj->pos = flen; // move file pointer to the end
if (do_WriteObject(obj, NULL, remain - flen) > 0) { // fill '\0' ...
uffs_Perror(UFFS_MSG_SERIOUS, "Write object not finished. expect %d but only %d wrote.",
remain - flen, fnode->u.file.len - flen);
obj->err = UEIOERR; // likely be an I/O error.
}
flen = obj->node->u.file.len;
}
}
else {
while (flen > remain) {
fdn = GetFdnByOfs(obj, flen - 1);
//uffs_BufFlushGroup(dev, obj->serial, fdn); //!< flush the buffer
block_start = GetStartOfDataBlock(obj, fdn);
if (remain <= block_start && fdn > 0) {
node = uffs_TreeFindDataNode(dev, obj->serial, fdn);
if (node == NULL) {
uffs_Perror(UFFS_MSG_SERIOUS,
"can't find data node when trancate obj.");
obj->err = UEIOERR;
goto ext;
}
bc = uffs_BlockInfoGet(dev, node->u.data.block);
if (bc == NULL) {
uffs_Perror(UFFS_MSG_SERIOUS,
"can't get block info when trancate obj.");
obj->err = UEIOERR;
goto ext;
}
for (page = 0; page < dev->attr->pages_per_block; page++) {
buf = uffs_BufFind(dev, fnode->u.file.serial, fdn, page);
if (buf) {
//!< ok, the buffer was loaded before ...
if (uffs_BufIsFree(buf) == U_FALSE) {
uffs_BlockInfoPut(dev, bc);
goto ext; //!< and someone is still holding the buffer,
// can't truncate it !!!
}
else if (run_opt == eREAL_RUN)
uffs_BufMarkEmpty(dev, buf); //!< discard the buffer
}
}
if (run_opt == eREAL_RUN) {
uffs_BreakFromEntry(dev, UFFS_TYPE_DATA, node);
uffs_FlashEraseBlock(dev, bc->block);
node->u.list.block = bc->block;
if (HAVE_BADBLOCK(dev))
uffs_BadBlockProcess(dev, node);
else
uffs_TreeInsertToErasedListTail(dev, node);
fnode->u.file.len = block_start;
}
flen = block_start;
uffs_BlockInfoPut(dev, bc);
}
else {
if (do_TruncateInternalWithBlockRecover(obj, fdn,
remain, run_opt) == U_SUCC) {
if (run_opt == eREAL_RUN)
fnode->u.file.len = remain;
flen = remain;
}
}
}
}
if (HAVE_BADBLOCK(dev))
uffs_BadBlockRecover(dev);
ext:
obj->pos = pos; // keep file pointer offset not changed.
uffs_Assert(fnode == obj->node, "obj->node change!\n");
return (obj->err == UENOERR ? U_SUCC : U_FAIL);
}
//
// 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);
}
/**
* read data from obj
*
* \param[in] obj uffs object
* \param[out] data output data buffer
* \param[in] len required length of data to be read from object->pos
*
* \return return bytes of data have been read
*/
int uffs_ReadObject(uffs_Object *obj, void *data, int len)
{
uffs_Device *dev = obj->dev;
TreeNode *fnode = NULL;
u32 remain = len;
u16 fdn;
u32 read_start;
TreeNode *dnode;
u32 size;
uffs_Buf *buf;
u32 blockOfs;
u16 page_id;
u8 type;
u32 pageOfs;
if (obj == NULL)
return 0;
fnode = obj->node;
if (obj->dev == NULL || obj->open_succ == U_FALSE) {
obj->err = UEBADF;
return 0;
}
if (obj->type == UFFS_TYPE_DIR) {
uffs_Perror(UFFS_MSG_NOISY, "Can't read data from a dir object!");
obj->err = UEBADF;
return 0;
}
if (obj->pos > fnode->u.file.len) {
return 0; //can't read file out of range
}
if (obj->oflag & UO_WRONLY) {
obj->err = UEACCES;
return 0;
}
uffs_ObjectDevLock(obj);
while (remain > 0) {
read_start = obj->pos + len - remain;
if (read_start >= fnode->u.file.len) {
//uffs_Perror(UFFS_MSG_NOISY, "read point out of file ?");
break;
}
fdn = GetFdnByOfs(obj, read_start);
if (fdn == 0) {
dnode = obj->node;
type = UFFS_TYPE_FILE;
}
else {
type = UFFS_TYPE_DATA;
dnode = uffs_TreeFindDataNode(dev, fnode->u.file.serial, fdn);
if (dnode == NULL) {
uffs_Perror(UFFS_MSG_SERIOUS, "can't get data node in entry!");
obj->err = UEUNKNOWN_ERR;
break;
}
}
blockOfs = GetStartOfDataBlock(obj, fdn);
page_id = (read_start - blockOfs) / dev->com.pg_data_size;
if (fdn == 0) {
/**
* fdn == 0: this means that the reading is start from the first block,
* since the page 0 is for file attr, so we move to the next page ID.
*/
page_id++;
}
buf = uffs_BufGetEx(dev, type, dnode, (u16)page_id, obj->oflag);
if (buf == NULL) {
uffs_Perror(UFFS_MSG_SERIOUS, "can't get buffer when read obj.");
obj->err = UEIOERR;
break;
}
pageOfs = read_start % dev->com.pg_data_size;
if (pageOfs >= buf->data_len) {
//uffs_Perror(UFFS_MSG_NOISY, "read data out of page range ?");
uffs_BufPut(dev, buf);
break;
}
size = (remain + pageOfs > buf->data_len ? buf->data_len - pageOfs : remain);
uffs_BufRead(dev, buf, (u8 *)data + len - remain, pageOfs, size);
uffs_BufPut(dev, buf);
remain -= size;
}
obj->pos += (len - remain);
if (HAVE_BADBLOCK(dev))
uffs_BadBlockRecover(dev);
uffs_ObjectDevUnLock(obj);
uffs_Assert(fnode == obj->node, "obj->node change!\n");
return len - remain;
}
/**
* write data to obj, from obj->pos
*
* \param[in] obj file obj
* \param[in] data data pointer
* \param[in] len length of data to be write
*
* \return bytes wrote to obj
*/
int uffs_WriteObject(uffs_Object *obj, const void *data, int len)
{
uffs_Device *dev = obj->dev;
TreeNode *fnode = obj->node;
int remain = len;
u16 fdn;
u32 write_start;
TreeNode *dnode;
u32 size;
if (obj == NULL)
return 0;
if (obj->dev == NULL || obj->open_succ != U_TRUE) {
obj->err = UEBADF;
return 0;
}
if (obj->type == UFFS_TYPE_DIR) {
uffs_Perror(UFFS_ERR_NOISY, "Can't write to an dir object!");
obj->err = UEACCES;
return 0;
}
if (obj->pos > fnode->u.file.len) {
return 0; //can't write file out of range
}
if (obj->oflag == UO_RDONLY) {
obj->err = UEACCES;
return 0;
}
uffs_ObjectDevLock(obj);
if (obj->oflag & UO_APPEND)
obj->pos = fnode->u.file.len;
while (remain > 0) {
write_start = obj->pos + len - remain;
if (write_start > fnode->u.file.len) {
uffs_Perror(UFFS_ERR_SERIOUS, "write point out of file ?");
break;
}
fdn = GetFdnByOfs(obj, write_start);
if (write_start == fnode->u.file.len && fdn > 0 &&
write_start == GetStartOfDataBlock(obj, fdn)) {
if (dev->tree.erased_count < MINIMUN_ERASED_BLOCK) {
uffs_Perror(UFFS_ERR_NOISY, "insufficient block in write obj, new block");
break;
}
size = do_WriteNewBlock(obj, (u8 *)data + len - remain, remain, fnode->u.file.serial, fdn);
//Flush immediately, so that the new data node will be created and put in the tree.
uffs_BufFlushGroup(dev, fnode->u.file.serial, fdn);
if (size == 0)
break;
remain -= size;
}
else {
if(fdn == 0)
dnode = obj->node;
else
dnode = uffs_TreeFindDataNode(dev, fnode->u.file.serial, fdn);
if(dnode == NULL) {
uffs_Perror(UFFS_ERR_SERIOUS, "can't find data node in tree ?");
obj->err = UEUNKNOWN;
break;
}
size = do_WriteInternalBlock(obj, dnode, fdn,
(u8 *)data + len - remain, remain,
write_start - GetStartOfDataBlock(obj, fdn));
#ifdef CONFIG_FLUSH_BUF_AFTER_WRITE
uffs_BufFlushGroup(dev, fnode->u.file.serial, fdn);
#endif
if (size == 0)
break;
remain -= size;
}
}
obj->pos += (len - remain);
if (HAVE_BADBLOCK(dev))
uffs_BadBlockRecover(dev);
uffs_ObjectDevUnLock(obj);
return len - remain;
}
/** truncate obj without lock device */
static URET do_TruncateObject(uffs_Object *obj, u32 remain, UBOOL dry_run)
{
uffs_Device *dev = obj->dev;
TreeNode *fnode = obj->node;
u16 fdn;
u32 flen;
u32 block_start;
TreeNode *node;
uffs_BlockInfo *bc;
uffs_Buf *buf;
u16 page;
if (obj->dev == NULL || obj->open_succ == U_FALSE || fnode == NULL) {
obj->err = UEBADF;
goto ext;
}
/* can't truncate a dir */
/* TODO: delete files under dir ? */
if (obj->type == UFFS_TYPE_DIR) {
obj->err = UEEXIST;
goto ext;
}
if (remain >= fnode->u.file.len) {
goto ext; //!< nothing to do ...
}
flen = fnode->u.file.len;
while (flen > remain) {
fdn = GetFdnByOfs(obj, flen - 1);
//uffs_BufFlushGroup(dev, obj->serial, fdn); //!< flush the buffer
block_start = GetStartOfDataBlock(obj, fdn);
if (remain <= block_start && fdn > 0) {
node = uffs_TreeFindDataNode(dev, obj->serial, fdn);
if (node == NULL) {
uffs_Perror(UFFS_ERR_SERIOUS, "can't find data node when trancate obj.");
obj->err = UEIOERR;
goto ext;
}
bc = uffs_BlockInfoGet(dev, node->u.data.block);
if (bc == NULL) {
uffs_Perror(UFFS_ERR_SERIOUS, "can't get block info when trancate obj.");
obj->err = UEIOERR;
goto ext;
}
for (page = 0; page < dev->attr->pages_per_block; page++) {
buf = uffs_BufFind(dev, fnode->u.file.serial, fdn, page);
if (buf) { //!< ok, the buffer was loaded before ...
if (uffs_BufIsFree(buf) == U_FALSE) {
uffs_BlockInfoPut(dev, bc);
goto ext; //!< and someone is still holding the buffer, can't truncate it !!!
}
else if (dry_run == U_FALSE)
uffs_BufMarkEmpty(dev, buf); //!< discard the buffer
}
}
if (dry_run == U_FALSE) {
uffs_BlockInfoExpire(dev, bc, UFFS_ALL_PAGES);
uffs_BreakFromEntry(dev, UFFS_TYPE_DATA, node);
uffs_FlashEraseBlock(dev, bc->block);
node->u.list.block = bc->block;
if (HAVE_BADBLOCK(dev))
uffs_BadBlockProcess(dev, node);
else
uffs_TreeInsertToErasedListTail(dev, node);
uffs_BlockInfoPut(dev, bc);
fnode->u.file.len = block_start;
}
else {
uffs_BlockInfoPut(dev, bc);
}
flen = block_start;
}
else {
if (do_TruncateInternalWithBlockRecover(obj, fdn, remain, dry_run) == U_SUCC) {
if (dry_run == U_FALSE)
fnode->u.file.len = remain;
flen = remain;
}
}
}
if (HAVE_BADBLOCK(dev))
uffs_BadBlockRecover(dev);
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);
}
