/*
* Read up to len bytes from the given inode, starting at seek bytes
* from the beginning of the inode. On success, return the number of
* bytes actually read, or 0 if the end of the file has been reached; on
* failure, return -errno.
*
* This function should allow reading from files or directories,
* treating them identically.
*
* Reading from a sparse block of the file should act like reading
* zeros; it should not cause the sparse blocks to be allocated.
*
* Similarly as in s5_write_file(), do not call s5_seek_to_block()
* directly from this function.
*
* If the region to be read would extend past the end of the file, less
* data will be read than was requested.
*
* You probably want to use pframe_get(), memcpy().
*/
int
s5_read_file(struct vnode *vnode, off_t seek, char *dest, size_t len)
{
dbg_print("s5_read_file: Reading File, Length: %i\n",len);
if(seek >= vnode->vn_len)
{
dbg_print("s5_read_file: Exiting with Value: 0\n");
return 0;
}
int block_index = S5_DATA_BLOCK(seek);
int block_offset = S5_DATA_OFFSET(seek);
int length;
if((int)len < vnode->vn_len - seek)
{
length = len;
}
else
{
length = vnode->vn_len - seek;
}
pframe_t *pf;
if(block_index < S5_NDIRECT_BLOCKS)
{
/* Direct Block */
dbg_print("s5_read_file: Reading from Direct Block\n");
pframe_get(&vnode->vn_mmobj, block_index, &pf);
pframe_pin(pf);
memcpy(dest,(char*)pf->pf_addr + block_offset, length);
}
else
{
s5_inode_t* inode = VNODE_TO_S5INODE(vnode);
if(inode->s5_indirect_block != 0)
{
dbg_print("s5_read_file: Reading from INDIRECT Block\n");
pframe_get(&vnode->vn_mmobj, inode->s5_indirect_block, &pf);
pframe_pin(pf);
memcpy(dest,(char*)pf->pf_addr + (block_index - S5_NDIRECT_BLOCKS), length);
}
else
{
return 0;
}
}
pframe_unpin(pf);
return length;
}
/*
* Return the number of blocks that this inode has allocated on disk.
* This should include the indirect block, but not include sparse
* blocks.
*
* This is only used by s5fs_stat().
*
* You'll probably want to use pframe_get().
*/
int
s5_inode_blocks(vnode_t *vnode)
{
/* NOT_YET_IMPLEMENTED("S5FS: s5_inode_blocks");
* return -1;
*/
s5_inode_t* inode = VNODE_TO_S5INODE(vnode);
int max_blocks = S5_DATA_BLOCK(vnode->vn_len);
int count = 0;
int block_index = 0;
while(block_index < max_blocks)
{
if(block_index < S5_NDIRECT_BLOCKS)
{
if(inode->s5_direct_blocks[block_index] != 0)
{
/* Not a sparse block */
count++;
}
}
else
{
/* Indirect block */
if(inode->s5_indirect_block == 0)
{
/* No indirect blocks */
/* Do Nothing */
}
else
{
pframe_t* pf;
pframe_get(S5FS_TO_VMOBJ(VNODE_TO_S5FS(vnode)),inode->s5_indirect_block,&pf);
pframe_pin(pf);
uint32_t indirect_map = block_index - S5_NDIRECT_BLOCKS;
uint32_t* block_array = (uint32_t*)pf->pf_addr;
if(block_array[indirect_map] != 0)
{
count++;
}
pframe_unpin(pf);
}
}
block_index++;
}
return count;
}
/*
* Read up to len bytes from the given inode, starting at seek bytes
* from the beginning of the inode. On success, return the number of
* bytes actually read, or 0 if the end of the file has been reached; on
* failure, return -errno.
*
* This function should allow reading from files or directories,
* treating them identically.
*
* Reading from a sparse block of the file should act like reading
* zeros; it should not cause the sparse blocks to be allocated.
*
* Similarly as in s5_write_file(), do not call s5_seek_to_block()
* directly from this function.
*
* If the region to be read would extend past the end of the file, less
* data will be read than was requested.
*
* You probably want to use pframe_get(), memcpy().
*/
int
s5_read_file(struct vnode *vnode, off_t seek, char *dest, size_t len)
{
if (seek < 0){
dbg(DBG_S5FS, "invalid seek value\n");
return -EINVAL;
} else if (seek >= vnode->vn_len){
return 0;
}
off_t start_pos = seek;
off_t end_pos = min(seek + len, vnode->vn_len);
off_t destpos = 0;
int get_res;
int read_size;
pframe_t *p;
while (start_pos + destpos < end_pos){
int data_offset = S5_DATA_OFFSET(seek);
get_res = pframe_get(&vnode->vn_mmobj, S5_DATA_BLOCK(seek), &p);
if (get_res < 0){
dbg(DBG_S5FS, "error getting page\n");
return get_res;
}
read_size = min(PAGE_SIZE - data_offset, end_pos - seek);
memcpy((void *) dest, (char *) p->pf_addr + data_offset, read_size);
destpos += read_size;
seek += read_size;
}
return destpos;
}
/*
* s5_seek_to_block:
* Return the disk-block number for the given seek pointer (aka file
* position).
* param vnode: pointer to vnode
* param seekptr: seek offset
* alloc: allocate new page or not
* return: the block number, or negative number on failure
*/
int
s5_seek_to_block(vnode_t *vnode, off_t seekptr, int alloc)
{
KASSERT(vnode != 0);
KASSERT(alloc == 1 || alloc == 0);
KASSERT(seekptr >= 0);
s5_inode_t* inode = VNODE_TO_S5INODE(vnode);
uint32_t block_number = S5_DATA_BLOCK(seekptr);
/* check if the block_number is valid */
if (block_number >= S5_NIDIRECT_BLOCKS + S5_NDIRECT_BLOCKS)
{
return -1;
}
if (block_number < S5_NDIRECT_BLOCKS)
{
/* sparse block */
if (inode->s5_direct_blocks[block_number] == 0)
{
/* alloc is zero, simply return */
if (alloc == 0)
{
return 0;
}
else
{
/* alloc a new disk block */
int block_num = s5_alloc_block(VNODE_TO_S5FS(vnode));
if (block_num < 0)
{
/* error */
return block_num;
}
else
{
/* add the new block to inode */
inode->s5_direct_blocks[block_number] = block_num;
/* dirty the inode */
s5_dirty_inode((VNODE_TO_S5FS(vnode)), inode);
return block_num;
}
}
}
else /* already there*/
{
return inode->s5_direct_blocks[block_number];
}
}
else
{
/* indirect blocks */
/* if the indirect block is zero, alloc it firstly */
pframe_t* page = NULL;
if (inode->s5_indirect_block == 0)
{
int block_num = 0;
if ((block_num = s5_alloc_block(FS_TO_S5FS(vnode->vn_fs))) < 0)
{
return block_num;
}
else
{
int ret = pframe_get(S5FS_TO_VMOBJ(FS_TO_S5FS(vnode->vn_fs)),
block_num, &page);
if (ret < 0 || page == NULL)
{
return ret;
}
else
{
pframe_pin(page);
memset(page->pf_addr, 0, S5_BLOCK_SIZE);
pframe_dirty(page);
pframe_unpin(page);
inode->s5_indirect_block = block_num;
s5_dirty_inode(FS_TO_S5FS(vnode->vn_fs), inode);
}
}
}
else
{
int ret = pframe_get(S5FS_TO_VMOBJ(FS_TO_S5FS(vnode->vn_fs)),
inode->s5_indirect_block, &page);
if (ret < 0 || page == NULL)
return ret;
}
KASSERT(page != NULL);
pframe_pin(page);
int off = block_number - S5_NDIRECT_BLOCKS;
int32_t* addr = ((int32_t*)page->pf_addr) + off;
pframe_unpin(page);
if (*addr == 0)
{
if (alloc == 0)
{
return 0;
}
else
{
int block_num = s5_alloc_block(VNODE_TO_S5FS(vnode));
if (block_num < 0)
{
return block_num;
}
else
{
pframe_pin(page);
*addr = block_num;
pframe_dirty(page);
pframe_unpin(page);
return block_num;
}
}
}
else
{
/* already there, return */
return *addr;
}
}
}
/*
* s5_read_file:
* Read up to len bytes from the given inode, starting at seek bytes
* from the beginning of the inode. On success, return the number of
* bytes actually read, or 0 if the end of the file has been reached; on
* failure, return -errno.
* param *vnode: the pointer to the vnode object
* param seek: the seek position
* param *bytes: the destination buffer
* param len: the length of the destination buffer in bytes
* return: the number of bytes actually read; on failure, return -errno.
*/
int
s5_read_file(struct vnode *vnode, off_t seek, char *dest, size_t len)
{
dbg(DBG_S5FS, "{\n");
KASSERT(vnode != NULL);
KASSERT(dest != NULL);
KASSERT(PAGE_SIZE == S5_BLOCK_SIZE);
KASSERT((uint32_t)vnode->vn_len == VNODE_TO_S5INODE(vnode)->s5_size);
if (seek >= vnode->vn_len)
{
return 0;/* EOF*/
}
uint32_t bytes = 0;
off_t start_pos = seek;
int start_block = S5_DATA_BLOCK(start_pos);
int ret = 0;
pframe_t* start = NULL;
pframe_t* end = NULL;
ret = pframe_get(&vnode->vn_mmobj, start_block, &start);
if (ret < 0)
{
return ret;
}
off_t end_pos = MIN(start_pos + (off_t)len, vnode->vn_len);
int end_block = S5_DATA_BLOCK(end_pos);
ret = pframe_get(&vnode->vn_mmobj, end_block, &end);
if (ret < 0)
{
return ret;
}
if (start == end) /* page same */
{
pframe_pin(start);
memcpy(dest, (char*)start->pf_addr + S5_DATA_OFFSET(start_pos),
end_pos - start_pos);
pframe_unpin(start);
bytes = end_pos - start_pos;
}
else
{
/* copy the start page */
pframe_pin(start);
memcpy(dest, (char*)start->pf_addr + S5_DATA_OFFSET(start_pos),
S5_BLOCK_SIZE-S5_DATA_OFFSET(start_pos));
pframe_unpin(start);
dest += (S5_BLOCK_SIZE - S5_DATA_OFFSET(start_pos));
bytes += (S5_BLOCK_SIZE - S5_DATA_OFFSET(start_pos));
/* find next page */
int off = start_pos + S5_BLOCK_SIZE - S5_DATA_OFFSET(start_pos);
while(1)
{
pframe_t* tmp = NULL;
int block_number = S5_DATA_BLOCK(off);
ret = pframe_get(&vnode->vn_mmobj, block_number, &tmp);
if (tmp == NULL)
{
dbg(DBG_S5FS, "}(error code returned)\n");
return ret;
}
if (tmp == end)
{
break;
} else
{
pframe_pin(tmp);
memcpy(dest, tmp->pf_addr, S5_BLOCK_SIZE);
pframe_unpin(tmp);
dest += S5_BLOCK_SIZE;/* shift the dest pointer */
bytes += S5_BLOCK_SIZE;
}
}
pframe_pin(end);
memcpy(dest, end->pf_addr, len - bytes);
pframe_unpin(end);
bytes = len;
dbg(DBG_S5FS, "}\n");
}
return bytes;
}
/*
* s5_write_file:
* write len bytes to the given inode, starting at seek bytes from the
* beginning of the inode. On success,
* param *vnode: the pointer to the vnode object
* param seek: the seek position
* param *bytes: the source buffer
* param len: the length of the source buffer in bytes
* return: the number of bytes actually written; on failure, return -errno.
*/
int
s5_write_file(vnode_t *vnode, off_t seek, const char *bytes, size_t len)
{
dbg(DBG_S5FS, "{\n");
KASSERT(vnode != NULL);
KASSERT(bytes != NULL);
KASSERT(PAGE_SIZE == S5_BLOCK_SIZE);
KASSERT((uint32_t)vnode->vn_len == VNODE_TO_S5INODE(vnode)->s5_size);
off_t start_pos = seek;
off_t start_block_offset = S5_DATA_OFFSET(start_pos);
off_t end_pos = MIN(seek + len, S5_MAX_FILE_BLOCKS*PAGE_SIZE);
off_t end_block_offset = S5_DATA_OFFSET(end_pos);
int start_block = S5_DATA_BLOCK(start_pos);
int end_block = S5_DATA_BLOCK(end_pos);
int ret = 0;
pframe_t* start = NULL;
ret = pframe_get(&vnode->vn_mmobj, start_block, &start);
if (ret < 0)
{
dbg(DBG_S5FS, "}(error code returend)\n");
return ret;
}
pframe_t* end = NULL;
ret = pframe_get(&vnode->vn_mmobj, end_block, &end);
if (ret < 0)
{
dbg(DBG_S5FS, "}(error code returend)\n");
return ret;
}
uint32_t num_bytes = 0;
if (start == end)
{
pframe_pin(start);
memcpy((char*)start->pf_addr + start_block_offset, bytes, len);
KASSERT((char*)start->pf_addr + start_block_offset + len ==
(char*)start->pf_addr + end_block_offset);
/* dirty the page */
pframe_dirty(start);
pframe_unpin(start);
num_bytes = len;
s5_inode_t* inode = VNODE_TO_S5INODE(vnode );
inode->s5_size = MAX(end_pos, vnode->vn_len);
vnode->vn_len = inode->s5_size;
s5_dirty_inode(VNODE_TO_S5FS(vnode),inode);
}
else
{
/* copy the start block */
pframe_pin(start);
memcpy((char*)start->pf_addr + start_block_offset, bytes,
S5_BLOCK_SIZE - start_block_offset);
bytes += S5_BLOCK_SIZE - start_block_offset;
num_bytes += S5_BLOCK_SIZE - start_block_offset;
pframe_dirty(start);
pframe_unpin(start);
s5_inode_t* inode = VNODE_TO_S5INODE(vnode );
inode->s5_size = MAX(start_pos + num_bytes, (uint32_t)vnode->vn_len);
vnode->vn_len = inode->s5_size;
while (1)
{
pframe_t* tmp;
int block_number = S5_DATA_BLOCK(start_pos + num_bytes );
ret = pframe_get(&vnode->vn_mmobj, block_number, &tmp);
if (tmp == NULL)
{
VNODE_TO_S5INODE(vnode)->s5_size = MAX(start_pos + num_bytes,
(uint32_t)vnode->vn_len);
vnode->vn_len = VNODE_TO_S5INODE(vnode)->s5_size;
s5_dirty_inode(VNODE_TO_S5FS(vnode),inode);
return ret;
}
if (tmp == end)
{
break;
}
pframe_pin(tmp);
memcpy(tmp->pf_addr, bytes, S5_BLOCK_SIZE);
pframe_dirty(tmp);
pframe_unpin(tmp);
bytes += S5_BLOCK_SIZE;
num_bytes += S5_BLOCK_SIZE;
}
/* copy the last one */
pframe_pin(end);
memcpy(end->pf_addr, bytes, len - num_bytes);
num_bytes += len - num_bytes; /* len */
pframe_dirty(end);
pframe_unpin(end);
/* add the size */
inode->s5_size = MAX(end_pos, vnode->vn_len);
s5_dirty_inode(VNODE_TO_S5FS(vnode),inode);
vnode->vn_len = inode->s5_size;
}
KASSERT((uint32_t)vnode->vn_len == VNODE_TO_S5INODE(vnode)->s5_size);
dbg(DBG_S5FS, "}\n");
return num_bytes;
}
/*
* Write len bytes to the given inode, starting at seek bytes from the
* beginning of the inode. On success, return the number of bytes
* actually written (which should be 'len', unless there's only enough
* room for a partial write); on failure, return -errno.
*
* This function should allow writing to files or directories, treating
* them identically.
*
* Writing to a sparse block of the file should cause that block to be
* allocated. Writing past the end of the file should increase the size
* of the file. Blocks between the end and where you start writing will
* be sparse.
*
* Do not call s5_seek_to_block() directly from this function. You will
* use the vnode's pframe functions, which will eventually result in a
* call to s5_seek_to_block().
*
* You will need pframe_dirty(), pframe_get(), memcpy().
*/
int
s5_write_file(vnode_t *vnode, off_t seek, const char *bytes, size_t len)
{
if (seek < 0){
dbg(DBG_S5FS, "invalid seek value\n");
return -EINVAL;
}
if (seek + len >= S5_MAX_FILE_SIZE){
len = S5_MAX_FILE_SIZE - seek - 1;
}
/* extend file size, if necessary */
uint32_t newlength = max(seek + len, vnode->vn_len);
/* if (seek + len > (unsigned) vnode->vn_len){*/
/*vnode->vn_len = seek + len;*/
/*VNODE_TO_S5INODE(vnode)->s5_size = vnode->vn_len;*/
/*s5_dirty_inode(VNODE_TO_S5FS(vnode), VNODE_TO_S5INODE(vnode));*/
/*}*/
off_t start_pos = seek;
/*off_t end_pos = min(seek + len, vnode->vn_len);*/
off_t end_pos = min(seek + len, newlength);
unsigned int srcpos = 0;
int get_res;
int write_size;
pframe_t *p;
uint32_t err = 0;
while (srcpos < len){
int data_offset = S5_DATA_OFFSET(seek);
get_res = pframe_get(&vnode->vn_mmobj, S5_DATA_BLOCK(seek), &p);
if (get_res < 0){
dbg(DBG_S5FS, "error getting page\n");
err = get_res;
break;
}
write_size = min(PAGE_SIZE - data_offset, end_pos - seek);
KASSERT(write_size >= 0 && "write size is negative");
memcpy((char *) p->pf_addr + data_offset, (void *) bytes, write_size);
int dirty_res = pframe_dirty(p);
if (dirty_res < 0){
err = dirty_res;
break;
}
srcpos += write_size;
seek += write_size;
}
if (seek > vnode->vn_len){
vnode->vn_len = seek;
VNODE_TO_S5INODE(vnode)->s5_size = vnode->vn_len;
s5_dirty_inode(VNODE_TO_S5FS(vnode), VNODE_TO_S5INODE(vnode));
}
return err ? err : srcpos;
}
/*
* Return the disk-block number for the given seek pointer (aka file
* position).
*
* If the seek pointer refers to a sparse block, and alloc is false,
* then return 0. If the seek pointer refers to a sparse block, and
* alloc is true, then allocate a new disk block (and make the inode
* point to it) and return it.
*
* Be sure to handle indirect blocks!
*
* If there is an error, return -errno.
*
* You probably want to use pframe_get, pframe_pin, pframe_unpin, pframe_dirty.
*/
int
s5_seek_to_block(vnode_t *vnode, off_t seekptr, int alloc)
{
int block_index = S5_DATA_BLOCK(seekptr);
if ((unsigned) block_index >= S5_MAX_FILE_BLOCKS){
dbg(DBG_S5FS, "file too large");
return -EFBIG;
}
if (seekptr > vnode->vn_len && !alloc){
return 0;
}
s5_inode_t *inode = VNODE_TO_S5INODE(vnode);
uint32_t block_num;
if (block_index >= S5_NDIRECT_BLOCKS){
pframe_t *ind_page;
mmobj_t *mmo = S5FS_TO_VMOBJ(VNODE_TO_S5FS(vnode));
if (inode->s5_indirect_block == 0){
if (!alloc){
return 0;
}
int alloc_res = alloc_indirect_block(vnode);
if (alloc_res < 0){
dbg(DBG_S5FS, "error allocating indirect block\n");
return alloc_res;
}
}
if (pframe_get(mmo, inode->s5_indirect_block, &ind_page) < 0){
panic("an indirect block is messed up\n");
}
block_num = ((uint32_t *) ind_page->pf_addr)[block_index - S5_NDIRECT_BLOCKS];
/* case where we've found a sparse block and need to allocate*/
if (block_num == 0 && alloc){
pframe_pin(ind_page);
int block_num = s5_alloc_block(VNODE_TO_S5FS(vnode));
pframe_unpin(ind_page);
if (block_num == -ENOSPC){
dbg(DBG_S5FS, "couldn't alloc a new block\n");
return -ENOSPC;
}
KASSERT(block_num > 0 && "forgot to handle an error case");
((uint32_t *) ind_page->pf_addr)[block_index - S5_NDIRECT_BLOCKS] = block_num;
int dirty_res = pframe_dirty(ind_page);
if (dirty_res < 0){
return dirty_res;
}
}
} else {
block_num = inode->s5_direct_blocks[block_index];
/* case where we've found a sparse block and need to allocate*/
if (block_num == 0 && alloc){
int block_num = s5_alloc_block(VNODE_TO_S5FS(vnode));
if (block_num == -ENOSPC){
dbg(DBG_S5FS, "couldn't alloc a new block\n");
return -ENOSPC;
}
KASSERT(block_num > 0 && "forgot to handle an error case");
inode->s5_direct_blocks[block_index] = block_num;
s5_dirty_inode(VNODE_TO_S5FS(vnode), inode);
}
}
return block_num;
}
/*
* Return the disk-block number for the given seek pointer (aka file
* position).
*
* If the seek pointer refers to a sparse block, and alloc is false,
* then return 0. If the seek pointer refers to a sparse block, and
* alloc is true, then allocate a new disk block (and make the inode
* point to it) and return it.
*
* Be sure to handle indirect blocks!
*
* If there is an error, return -errno.
*
* You probably want to use pframe_get, pframe_pin, pframe_unpin, pframe_dirty.
*/
int
s5_seek_to_block(vnode_t *vnode, off_t seekptr, int alloc)
{
/* CASE BLOCK TYPE ALLOC Direct Sparse Indirect Sparse WAT DO?
* 1 (BLOCK > Total Blocks) Return Error
* 2 DIRECT FALSE TRUE N/A return block from s5_direct_blocks
* 3 DIRECT TRUE TRUE N/A allocate new block and point inode (also memcpy)
* 4 DIRECT TRUE FALSE N/A return block from s5_direct_blocks
* 5 INDIRECT FALSE TRUE TRUE return 0
* 7 INDIRECT FALSE FALSE FALSE Find block we want
* 8 INDIRECT TRUE FALSE FALSE Find block we want
* 9 INDIRECT TRUE TRUE FALSE allocate new block, memcpy to 0, set data address in indirect
* * INDIRECT TRUE N/A TRUE allocate new block, pframe_get on inode->indirect_block
*/
dbg_print("s5_seek_to_block: Entering Function, seekptr: %i, alloc: %i\n",seekptr,alloc);
s5fs_t* vnode_s5fs = VNODE_TO_S5FS(vnode);
s5_inode_t* vnode_inode = VNODE_TO_S5INODE(vnode);
struct mmobj* vnode_vmobj = S5FS_TO_VMOBJ(vnode_s5fs);
uint32_t data_block = S5_DATA_BLOCK(seekptr);
pframe_t* pf;
dbg_print("s5_seek_to_block: a\n");
if(data_block > S5_MAX_FILE_BLOCKS)
{
/* Case 1 */
dbg_print("s5_seek_to_block: Case 1\n");
return 0;
}
if(data_block < S5_NDIRECT_BLOCKS)
{
dbg_print("s5_seek_to_block: b\n");
/* Direct Block */
if(!alloc)
{
/* ALLOC FALSE */
/* CASE 2 */
dbg_print("s5_seek_to_block: c\n");
dbg_print("s5_seek_to_block: Case 2\n");
return vnode_inode->s5_direct_blocks[data_block];
}
else
{
/* ALLOC TRUE */
dbg_print("s5_seek_to_block: d\n");
if(vnode_inode->s5_direct_blocks[data_block] == 0)
{
/* Sparse Block */
/* CASE 3 */
dbg_print("s5_seek_to_block: e\n");
pframe_get(vnode_vmobj,data_block,&pf);
pframe_pin(pf);
int block_alloc = s5_alloc_block(vnode_s5fs);
dbg_print("s5_seek_to_block: f\n");
if(block_alloc == -ENOSPC)
{
/* Allocation Failure */
dbg_print("s5_seek_to_block: g\n");
pframe_unpin(pf);
dbg_print("s5_seek_to_block: Allocation Failure #1\n");
return -ENOSPC;
}
else
{
/* Success in Allocation, Connect Inode and Dirty */
dbg_print("s5_seek_to_block: h\n");
vnode_inode->s5_direct_blocks[data_block] = block_alloc;
/* memset(pf->pf_addr, 0, PAGE_SIZE); */
pframe_dirty(pf);
s5_dirty_inode(vnode_s5fs,vnode_inode);
pframe_unpin(pf);
dbg_print("s5_seek_to_block: Case 3\n");
return block_alloc;
}
}
else
{
/* Not Sparse Block */
/* CASE 4 */
dbg_print("s5_seek_to_block: Case 4\n");
return vnode_inode->s5_direct_blocks[data_block];
}
}
}
else
{
/* Indirect Block */
dbg_print("s5_seek_to_block: i\n");
if(!alloc)
{
/* ALLOC FALSE */
dbg_print("s5_seek_to_block: j\n");
if(vnode_inode->s5_indirect_block == 0)
{
/* Sparse Block */
/* CASE 5 */
dbg_print("s5_seek_to_block: Case 5\n");
return 0;
}
else
{
/* Not Sparse Block */
/* CASE 7 */
dbg_print("s5_seek_to_block: Case 7\n");
return vnode_inode->s5_direct_blocks[data_block - S5_NDIRECT_BLOCKS];
}
}
else
{
/* ALLOC TRUE */
dbg_print("s5_seek_to_block: k\n");
if(vnode_inode->s5_indirect_block == 0)
{
/* Sparse Block */
/* CASE 5 */
dbg_print("s5_seek_to_block: l\n");
int indirect_alloc = s5_alloc_block(vnode_s5fs);
if(indirect_alloc == -ENOSPC)
{
/* Allocation Failure */
dbg_print("s5_seek_to_block: Allocation Failure #2\n");
return -ENOSPC;
}
/* Success in Allocation, Connect Inode and Dirty */
dbg_print("s5_seek_to_block: m\n");
pframe_get(vnode_vmobj,vnode_inode->s5_indirect_block,&pf);
pframe_pin(pf);
/* memset(pf->pf_addr, 0, PAGE_SIZE); */
vnode_inode->s5_indirect_block = indirect_alloc;
pframe_dirty(pf);
s5_dirty_inode(vnode_s5fs,vnode_inode);
dbg_print("s5_seek_to_block: n\n");
}
else
{
/* Not Sparse Block */
dbg_print("s5_seek_to_block: o\n");
pframe_get(vnode_vmobj,vnode_inode->s5_indirect_block,&pf);
pframe_pin(pf);
}
dbg_print("s5_seek_to_block: p\n");
uint32_t indirect_map = data_block - S5_NDIRECT_BLOCKS;
uint32_t* block_array = (uint32_t*)pf->pf_addr;
int direct_index = block_array[indirect_map];
if(direct_index == 0)
{
dbg_print("s5_seek_to_block: q\n");
direct_index = s5_alloc_block(vnode_s5fs);
if(direct_index == -ENOSPC)
{
/* Allocation Failure */
dbg_print("s5_seek_to_block: Allocation Failure #3\n");
return -ENOSPC;
}
}
dbg_print("s5_seek_to_block: rn");
block_array[indirect_map] = direct_index;
pframe_dirty(pf);
pframe_unpin(pf);
dbg_print("s5_seek_to_block: Case 6\n");
return direct_index;
}
}
/* NOT_YET_IMPLEMENTED("S5FS: s5_seek_to_block");
* return -1;
*/
}
/*
* Write len bytes to the given inode, starting at seek bytes from the
* beginning of the inode. On success, return the number of bytes
* actually written (which should be 'len', unless there's only enough
* room for a partial write); on failure, return -errno.
*
* This function should allow writing to files or directories, treating
* them identically.
*
* Writing to a sparse block of the file should cause that block to be
* allocated. Writing past the end of the file should increase the size
* of the file. Blocks between the end and where you start writing will
* be sparse.
*
* Do not call s5_seek_to_block() directly from this function. You will
* use the vnode's pframe functions, which will eventually result in a
* call to s5_seek_to_block().
*
* You will need pframe_dirty(), pframe_get(), memcpy().
*/
int
s5_write_file(vnode_t *vnode, off_t seek, const char *bytes, size_t len)
{
dbg_print("s5_write_file: Writing to File, Length: %i\n",len);
uint32_t to_write = len;
/* Block Number */
uint32_t block_index = S5_DATA_BLOCK(seek);
if(block_index >= S5_MAX_FILE_BLOCKS)
{
dbg_print("s5_write_file: Exiting with Value: 0\n");
return 0;
}
/* Offset within block */
uint32_t block_offset = S5_DATA_OFFSET(seek);
uint32_t remaining = S5_BLOCK_SIZE - block_offset;
int total_written = 0;
s5_inode_t* inode = VNODE_TO_S5INODE(vnode);
s5fs_t* dir_fs = VNODE_TO_S5FS(vnode);
if(seek >= vnode->vn_len)
{
/* End to Start of Writing should be written as sparse */
}
while(to_write > 0)
{
pframe_t* pf;
pframe_get(&(vnode->vn_mmobj),block_index,&pf);
pframe_pin(pf);
if(to_write <= remaining)
{
memcpy((char*)pf->pf_addr + block_offset,bytes + total_written,to_write);
total_written += to_write;
block_offset = 0;
to_write = 0;
}
else
{
/* to_write > remaining */
memcpy((char*)pf->pf_addr + block_offset,bytes + total_written,remaining);
total_written += remaining;
block_offset = 0;
to_write -= remaining;
block_index++;
remaining = S5_BLOCK_SIZE;
if(block_index == S5_MAX_FILE_BLOCKS)
{
break;
}
}
pframe_dirty(pf);
pframe_unpin(pf);
}
if(seek + total_written > vnode->vn_len)
{
vnode->vn_len = seek + total_written;
inode->s5_size = seek + total_written;
}
s5_dirty_inode(dir_fs,inode);
return total_written;
}