/*
* See the comment in vfs.h for what is expected of this function.
*
* When this function returns, the inode refcount should be decremented.
*
* You probably want to use s5_free_inode() if there are no more links to
* the inode, and dont forget to unpin the page
*/
static void
s5fs_delete_vnode(vnode_t *vnode)
{
pframe_t *p;
mmobj_t *fs_mmobj = S5FS_TO_VMOBJ(VNODE_TO_S5FS(vnode));
if (pframe_get(fs_mmobj, S5_INODE_BLOCK(vnode->vn_vno), &p)){
panic("pframe_get failed. What the hell do we do?\n");
}
s5_inode_t *inode = ((s5_inode_t *) p->pf_addr) + S5_INODE_OFFSET(vnode->vn_vno);
dbg(DBG_S5FS, "decrementing link count on inode %d from %d to %d\n",
inode->s5_number, inode->s5_linkcount,inode->s5_linkcount - 1);
inode->s5_linkcount--;
if (inode->s5_linkcount == 0){
s5_free_inode(vnode);
} else {
s5_dirty_inode(VNODE_TO_S5FS(vnode), inode);
}
pframe_unpin(p);
}
/*
* Read fs->fs_dev and set fs_op, fs_root, and fs_i.
*
* Point fs->fs_i to an s5fs_t*, and initialize it. Be sure to
* verify the superblock (using s5_check_super()). Use vget() to get
* the root vnode for fs_root.
*
* Return 0 on success, negative on failure.
*/
int
s5fs_mount(struct fs *fs)
{
int num;
blockdev_t *dev;
s5fs_t *s5;
pframe_t *vp;
KASSERT(fs);
if (sscanf(fs->fs_dev, "disk%d", &num) != 1) {
return -EINVAL;
}
if (!(dev = blockdev_lookup(MKDEVID(1, num)))) {
return -EINVAL;
}
/* allocate and initialize an s5fs_t: */
s5 = (s5fs_t *)kmalloc(sizeof(s5fs_t));
if (!s5)
return -ENOMEM;
/* init s5f_disk: */
s5->s5f_bdev = dev;
/* init s5f_super: */
pframe_get(S5FS_TO_VMOBJ(s5), S5_SUPER_BLOCK, &vp);
KASSERT(vp);
s5->s5f_super = (s5_super_t *)(vp->pf_addr);
if (s5_check_super(s5->s5f_super)) {
/* corrupt */
kfree(s5);
return -EINVAL;
}
pframe_pin(vp);
/* init s5f_mutex: */
kmutex_init(&s5->s5f_mutex);
/* init s5f_fs: */
s5->s5f_fs = fs;
/* Init the members of fs that we (the fs-implementation) are
* responsible for initializing: */
fs->fs_i = s5;
fs->fs_op = &s5fs_fsops;
fs->fs_root = vget(fs, s5->s5f_super->s5s_root_inode);
return 0;
}
/*
* s5_alloc_block:
* Allocate a new disk-block off the block free list and return it.
* param *fs: the pointer to the file system object
* return: the block number, or negative number if no space
*/
static int
s5_alloc_block(s5fs_t *fs)
{
dbg(DBG_S5FS, "{\n");
KASSERT(fs != NULL);
lock_s5(fs);
s5_super_t* super = fs->s5f_super;
pframe_t* next_free_block = NULL;
int ret = 0;
int block_number = 0;
if (super->s5s_nfree == 0) /* no free pages */
{
int ret = pframe_get( S5FS_TO_VMOBJ(fs),
super->s5s_free_blocks[S5_NBLKS_PER_FNODE - 1],
&next_free_block);
if (ret < 0 || next_free_block == NULL)
{
/* No more free blocks */
unlock_s5(fs);
dbg(DBG_S5FS, "}(error code returned)\n");
return -ENOSPC;
}
else
{
block_number = super->s5s_free_blocks[S5_NBLKS_PER_FNODE - 1];
/* copy the next free block into the super block */
memcpy((void*)(super->s5s_free_blocks), next_free_block->pf_addr,
S5_NBLKS_PER_FNODE * sizeof(uint32_t));
memset(next_free_block->pf_addr, 0, S5_BLOCK_SIZE);
pframe_dirty(next_free_block);
pframe_clean(next_free_block);
pframe_free(next_free_block);
/* now full */
super->s5s_nfree = S5_NBLKS_PER_FNODE-1;
s5_dirty_super(fs);
unlock_s5(fs);
dbg(DBG_S5FS, "}\n");
return block_number;
}
}
else /* there is some free pages */
{
block_number = super->s5s_free_blocks[super->s5s_nfree - 1];
super->s5s_nfree--;
s5_dirty_super(fs);
unlock_s5(fs);
dbg(DBG_S5FS, "}\n");
return block_number;
}
}
/*
* Allocate a new disk-block off the block free list and return it. If
* there are no free blocks, return -ENOSPC.
*
* This will not initialize the contents of an allocated block; these
* contents are undefined.
*
* If the super block's s5s_nfree is 0, you need to refill
* s5s_free_blocks and reset s5s_nfree. You need to read the contents
* of this page using the pframe system in order to obtain the next set of
* free block numbers.
*
* Don't forget to dirty the appropriate blocks!
*
* You'll probably want to use lock_s5(), unlock_s5(), pframe_get(),
* and s5_dirty_super()
*/
static int
s5_alloc_block(s5fs_t *fs)
{
dbg_print("s5_alloc_block: Entering Function\n");
/* get the super block frame */
s5_super_t* superblock = fs->s5f_super;
int block_return;
lock_s5(fs);
if(((int)superblock->s5s_free_blocks[S5_NBLKS_PER_FNODE - 1] == -1)
&& (superblock->s5s_nfree == 0))
{
dbg_print("s5_alloc_block: No free blocks, returning error");
unlock_s5(fs);
return -ENOSPC;
}
if(superblock->s5s_nfree == 0)
{
dbg_print("s5_alloc_block: Out of free blocks, getting more!\n");
struct mmobj* fs_vmobj = S5FS_TO_VMOBJ(fs);
int next_block = superblock->s5s_free_blocks[S5_NBLKS_PER_FNODE - 1];
pframe_t* pf;
pframe_get(fs_vmobj,next_block,&pf);
pframe_pin(pf);
memcpy(((char*)superblock->s5s_free_blocks),pf->pf_addr,S5_NBLKS_PER_FNODE * sizeof(uint32_t));
superblock->s5s_nfree = S5_NBLKS_PER_FNODE - 1;
block_return = next_block;
pframe_unpin(pf);
}
else
{
/* Frre blocks are available */
dbg_print("s5_alloc_block: Free block available\n");
superblock->s5s_nfree--;
block_return = superblock->s5s_free_blocks[superblock->s5s_nfree];
}
s5_dirty_super(fs);
unlock_s5(fs);
dbg_print("s5_alloc_block: Exiting Function\n");
return block_return;
/* NOT_YET_IMPLEMENTED("S5FS: s5_alloc_block");
* return -1;
*/
}
/*
* 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;
}
/*
* See the comment in vfs.h for what is expected of this function.
*
* When this function returns, the inode link count should be incremented.
* Note that most UNIX filesystems don't do this, they have a separate
* flag to indicate that the VFS is using a file. However, this is
* simpler to implement.
*
* To get the inode you need to use pframe_get then use the pf_addr
* and the S5_INODE_OFFSET(vnode) to get the inode
*
* Don't forget to update linkcounts and pin the page.
*
* Note that the devid is stored in the indirect_block in the case of
* a char or block device
*
* Finally, the main idea is to do special initialization based on the
* type of inode (i.e. regular, directory, char/block device, etc').
*
*/
static void
s5fs_read_vnode(vnode_t *vnode)
{
pframe_t *p;
mmobj_t *fs_mmobj = S5FS_TO_VMOBJ(VNODE_TO_S5FS(vnode));
if (pframe_get(fs_mmobj, S5_INODE_BLOCK(vnode->vn_vno), &p)){
panic("pframe_get failed. What the hell do we do?\n");
}
pframe_pin(p);
s5_inode_t *inode = ((s5_inode_t *) p->pf_addr) + S5_INODE_OFFSET(vnode->vn_vno);
/* generic initializations */
vnode->vn_len = inode->s5_size;
vnode->vn_i = (void *) inode;
inode->s5_linkcount++;
/* type-specific initializations */
KASSERT(inode->s5_type == S5_TYPE_DATA
|| inode->s5_type == S5_TYPE_DIR
|| inode->s5_type == S5_TYPE_CHR
|| inode->s5_type == S5_TYPE_BLK);
switch (inode->s5_type){
case S5_TYPE_DATA:
vnode->vn_ops = &s5fs_file_vops;
vnode->vn_mode = S_IFREG;
break;
case S5_TYPE_DIR:
vnode->vn_ops = &s5fs_dir_vops;
vnode->vn_mode = S_IFDIR;
break;
case S5_TYPE_CHR:
vnode->vn_mode = S_IFCHR;
vnode->vn_devid = inode->s5_indirect_block;
break;
default: /* S5_TYPE_BLK */
vnode->vn_mode = S_IFBLK;
vnode->vn_devid = inode->s5_indirect_block;
}
s5_dirty_inode(VNODE_TO_S5FS(vnode), inode);
}
/* allocated an indirect block for a vnode who's indirect block is currently sparse */
static int alloc_indirect_block(vnode_t *v){
/* an array of 0's that we'll use to quickly create blocks of zeros */
static int zero_array[BLOCK_SIZE] = {};
s5_inode_t *inode = VNODE_TO_S5INODE(v);
KASSERT(inode->s5_indirect_block == 0);
/* first, get an indirect block */
int indirect_block = s5_alloc_block(VNODE_TO_S5FS(v));
if (indirect_block == -ENOSPC){
dbg(DBG_S5FS, "couldn't alloc a new block\n");
return -ENOSPC;
}
KASSERT(indirect_block > 0 && "forgot to handle an error case");
/* then, zero it */
pframe_t *ind_page;
mmobj_t *mmo = S5FS_TO_VMOBJ(VNODE_TO_S5FS(v));
int get_res = pframe_get(mmo, indirect_block, &ind_page);
if (get_res < 0){
return get_res;
}
memcpy(ind_page->pf_addr, zero_array, BLOCK_SIZE);
int dirty_res = pframe_dirty(ind_page);
if (dirty_res < 0){
return dirty_res;
}
/* finally, set this block to be the indirect block of the inode */
inode->s5_indirect_block = indirect_block;
s5_dirty_inode(VNODE_TO_S5FS(v), inode);
return 0;
}
/*
* s5fs_check_refcounts()
* vput root vnode
*/
static int
s5fs_umount(fs_t *fs)
{
s5fs_t *s5 = (s5fs_t *)fs->fs_i;
blockdev_t *bd = s5->s5f_bdev;
pframe_t *sbp;
int ret;
if (s5fs_check_refcounts(fs)) {
dbg(DBG_PRINT, "s5fs_umount: WARNING: linkcount corruption "
"discovered in fs on block device with major %d "
"and minor %d!!\n", MAJOR(bd->bd_id), MINOR(bd->bd_id));
}
if (s5_check_super(s5->s5f_super)) {
dbg(DBG_PRINT, "s5fs_umount: WARNING: corrupted superblock "
"discovered on fs on block device with major %d "
"and minor %d!!\n", MAJOR(bd->bd_id), MINOR(bd->bd_id));
}
vnode_flush_all(fs);
vput(fs->fs_root);
if (0 > (ret = pframe_get(S5FS_TO_VMOBJ(s5), S5_SUPER_BLOCK, &sbp))) {
panic("s5fs_umount: failed to pframe_get super block. "
"This should never happen (the page should already "
"be resident and pinned, and even if it wasn't, "
"block device readpage entry point does not "
"fail.\n");
}
KASSERT(sbp);
pframe_unpin(sbp);
kfree(s5);
blockdev_flush_all(bd);
return 0;
}
/*
* s5fs_delete_vnode:
* s5fs_delete_vnode is called by vput when the
* specified vnode_t no longer needs to exist
* param *vnode: the pointer to the vnode object
*/
static void
s5fs_delete_vnode(vnode_t *vnode)
{
dbg(DBG_S5FS, "{\n");
KASSERT(vnode != NULL);
KASSERT(vnode->vn_fs != NULL);
/* Lock */
kmutex_lock(&vnode->vn_mutex);
pframe_t* page = NULL;
int ret = pframe_get(S5FS_TO_VMOBJ(FS_TO_S5FS(vnode->vn_fs)),
S5_INODE_BLOCK(vnode->vn_vno), &page);
KASSERT(ret == 0);
KASSERT(page != NULL);
s5_inode_t* inode = ((s5_inode_t*)page->pf_addr) +
S5_INODE_OFFSET(vnode->vn_vno);
inode->s5_linkcount--;
s5_dirty_inode(VNODE_TO_S5FS(vnode), inode);
KASSERT(VNODE_TO_S5INODE(vnode) == inode);
KASSERT(inode->s5_linkcount >= 0);
if (inode->s5_linkcount== 0)
{
s5_free_inode(vnode);
}
pframe_unpin(page);
/* Unlock */
kmutex_unlock(&vnode->vn_mutex);
dbg(DBG_S5FS, "}\n");
}
/*
* 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)
{
s5_inode_t *inode = VNODE_TO_S5INODE(vnode);
int allocated_blocks = 0;
int i;
for (i = 0; i < S5_NDIRECT_BLOCKS; i++){
if (inode->s5_direct_blocks[i] != 0){
allocated_blocks++;
}
}
if (inode->s5_indirect_block == 0){
return allocated_blocks;
}
/* count the indirect block as an allocated block */
allocated_blocks++;
pframe_t *p;
mmobj_t *mmobj = S5FS_TO_VMOBJ(VNODE_TO_S5FS(vnode));
int get_res = pframe_get(mmobj, inode->s5_indirect_block, &p);
if (get_res < 0){
return get_res;
}
int j;
for (j = 0; j < S5_NDIRECT_BLOCKS; j++){
if (((int *)p->pf_addr)[j] != 0){
allocated_blocks++;
}
}
return allocated_blocks;
}
/*
* s5_inode_blocks:
* Return the number of blocks that this inode has allocated on disk.
* This should include the indirect block, but not include sparse
* blocks.
* param *vnode: the pointer to the vnode object
* return: the number of blocks that this inode has allocated
*/
int
s5_inode_blocks(vnode_t *vnode)
{
dbg(DBG_S5FS, "{\n");
KASSERT(vnode != NULL);
s5_inode_t* inode = VNODE_TO_S5INODE(vnode);
/* Firstly count number of direct blocks */
int num = 0;
uint32_t i = 0;
for (i = 0; i < S5_NDIRECT_BLOCKS; i++)
{
if (inode->s5_direct_blocks[i] != 0)
{
num++;
}
}
/* Secondly count the number of indirect blocks */
pframe_t* page = NULL;
/* May block */
int ret = pframe_get(S5FS_TO_VMOBJ(FS_TO_S5FS(vnode->vn_fs)),
inode->s5_indirect_block, &page);
KASSERT(ret == 0);
KASSERT(page != NULL);
/* Conver to array */
uint32_t* pageptr = (uint32_t*)(page->pf_addr);
for (i = 0; i < S5_NIDIRECT_BLOCKS; i++, pageptr++)
{
if (*pageptr != 0)
{
num++;
}
}
dbg(DBG_S5FS, "}\n");
return num;
}
/*
* s5_free_inode:
* Free an inode by freeing its disk blocks and putting it back on the
* inode free list.
* param *vnode: the pointer to the vnode object
*/
void
s5_free_inode(vnode_t *vnode)
{
uint32_t i = 0;
s5_inode_t *inode = VNODE_TO_S5INODE(vnode);
s5fs_t *fs = VNODE_TO_S5FS(vnode);
KASSERT((S5_TYPE_DATA == inode->s5_type)
|| (S5_TYPE_DIR == inode->s5_type)
|| (S5_TYPE_CHR == inode->s5_type)
|| (S5_TYPE_BLK == inode->s5_type));
/* free any direct blocks */
for (i = 0; i < S5_NDIRECT_BLOCKS; ++i)
{
if (inode->s5_direct_blocks[i])
{
dprintf("freeing block %d\n", inode->s5_direct_blocks[i]);
s5_free_block(fs, inode->s5_direct_blocks[i]);
s5_dirty_inode(fs, inode);
inode->s5_direct_blocks[i] = 0;
}
}
if (((S5_TYPE_DATA == inode->s5_type)
|| (S5_TYPE_DIR == inode->s5_type))
&& inode->s5_indirect_block)
{
pframe_t *ibp;
uint32_t *b;
pframe_get(S5FS_TO_VMOBJ(fs),
(unsigned)inode->s5_indirect_block,
&ibp);
KASSERT(ibp
&& "because never fails for block_device "
"vm_objects");
pframe_pin(ibp);
b = (uint32_t *)(ibp->pf_addr);
for (i = 0; i < S5_NIDIRECT_BLOCKS; ++i)
{
KASSERT(b[i] != inode->s5_indirect_block);
if (b[i])
s5_free_block(fs, b[i]);
}
pframe_unpin(ibp);
s5_free_block(fs, inode->s5_indirect_block);
}
inode->s5_indirect_block = 0;
inode->s5_type = S5_TYPE_FREE;
s5_dirty_inode(fs, inode);
lock_s5(fs);
inode->s5_next_free = fs->s5f_super->s5s_free_inode;
fs->s5f_super->s5s_free_inode = inode->s5_number;
unlock_s5(fs);
s5_dirty_inode(fs, inode);
s5_dirty_super(fs);
}
/*
* 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;
}
}
}
/*
* 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;
*/
}
/*
* s5fs_read_vnode:
* s5fs_read_vnode will be passed a vnode_t*, which will have its vn_fs
* and vn_vno fields initialized.
* param *vnode: the pointer to the vnode object
*/
static void
s5fs_read_vnode(vnode_t *vnode)
{
dbg(DBG_S5FS, "{\n");
KASSERT(vnode != NULL);
KASSERT(vnode->vn_fs != NULL);
kmutex_lock(&vnode->vn_mutex);
pframe_t* page = NULL;
int ret = pframe_get(S5FS_TO_VMOBJ(FS_TO_S5FS(vnode->vn_fs)),
S5_INODE_BLOCK(vnode->vn_vno), &page);
KASSERT(ret == 0);
KASSERT(page != NULL);
pframe_pin(page);
s5_inode_t* inode = ((s5_inode_t*)page->pf_addr) +
S5_INODE_OFFSET(vnode->vn_vno);
inode->s5_linkcount++;
s5_dirty_inode(VNODE_TO_S5FS(vnode), inode);
vnode->vn_i = inode;
vnode->vn_len = inode->s5_size;
switch(inode->s5_type)
{
case S5_TYPE_DIR:
{
vnode->vn_mode = S_IFDIR;
vnode->vn_ops = &s5fs_dir_vops;
break;
}
case S5_TYPE_DATA:
{
vnode->vn_mode = S_IFREG;
vnode->vn_ops = &s5fs_file_vops;
break;
}
case S5_TYPE_CHR:
{
vnode->vn_mode = S_IFCHR;
vnode->vn_ops = NULL;
vnode->vn_devid = (devid_t)(inode->s5_indirect_block);
vnode->vn_cdev = bytedev_lookup(vnode->vn_devid);
break;
}
case S5_TYPE_BLK:
{
vnode->vn_mode = S_IFBLK;
vnode->vn_ops = NULL;
vnode->vn_devid = (devid_t)(inode->s5_indirect_block);
vnode->vn_bdev = blockdev_lookup(vnode->vn_devid);
break;
}
default:
{
panic("inode %d has unknown/invalid type %d!!\n",
(int)vnode->vn_vno, (int)inode->s5_type);
}
}
kmutex_unlock(&vnode->vn_mutex);
dbg(DBG_S5FS, "}\n");
}