/*
* 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;
}
}
/*
* s5_free_block
* Given a filesystem and a block number, frees the given block in the
* filesystem.
*
* This function may potentially block.
* param *fs: the pointer to the file system
* param blockno: the block number
*/
static void
s5_free_block(s5fs_t *fs, int blockno)
{
s5_super_t *s = fs->s5f_super;
lock_s5(fs);
KASSERT(S5_NBLKS_PER_FNODE > s->s5s_nfree);
if ((S5_NBLKS_PER_FNODE - 1) == s->s5s_nfree)
{
/* get the pframe where we will store the free block nums */
pframe_t *prev_free_blocks = NULL;
KASSERT(fs->s5f_bdev);
pframe_get(&fs->s5f_bdev->bd_mmobj, blockno, &prev_free_blocks);
KASSERT(prev_free_blocks->pf_addr);
/* copy from the superblock to the new block on disk */
memcpy(prev_free_blocks->pf_addr, (void *)(s->s5s_free_blocks),
S5_NBLKS_PER_FNODE * sizeof(int));
pframe_dirty(prev_free_blocks);
/* reset s->s5s_nfree and s->s5s_free_blocks */
s->s5s_nfree = 0;
s->s5s_free_blocks[S5_NBLKS_PER_FNODE - 1] = blockno;
}
else
{
s->s5s_free_blocks[s->s5s_nfree++] = blockno;
}
s5_dirty_super(fs);
unlock_s5(fs);
}
/*
* s5_alloc_inode:
* Creates a new inode from the free list and initializes its fields.
* Uses S5_INODE_BLOCK to get the page from which to create the inode
*
* This function may block.
* param *fs: the pointer to the file system
* param type: the type of this new inode
* param devid: device id
* return: the inode number, or -1 for any errors
*/
int
s5_alloc_inode(fs_t *fs, uint16_t type, devid_t devid)
{
s5fs_t *s5fs = FS_TO_S5FS(fs);
pframe_t *inodep = NULL;
s5_inode_t *inode = NULL;
int ret = -1;
KASSERT((S5_TYPE_DATA == type)
|| (S5_TYPE_DIR == type)
|| (S5_TYPE_CHR == type)
|| (S5_TYPE_BLK == type));
lock_s5(s5fs);
if (s5fs->s5f_super->s5s_free_inode == (uint32_t) - 1)
{
unlock_s5(s5fs);
return -ENOSPC;
}
pframe_get(&s5fs->s5f_bdev->bd_mmobj,
S5_INODE_BLOCK(s5fs->s5f_super->s5s_free_inode), &inodep);
KASSERT(inodep);
inode = (s5_inode_t *)(inodep->pf_addr)
+ S5_INODE_OFFSET(s5fs->s5f_super->s5s_free_inode);
KASSERT(inode->s5_number == s5fs->s5f_super->s5s_free_inode);
ret = inode->s5_number;
/* reset s5s_free_inode; remove the inode from the inode free list: */
s5fs->s5f_super->s5s_free_inode = inode->s5_next_free;
pframe_pin(inodep);
s5_dirty_super(s5fs);
pframe_unpin(inodep);
/* init the newly-allocated inode: */
inode->s5_size = 0;
inode->s5_type = type;
inode->s5_linkcount = 0;
memset(inode->s5_direct_blocks, 0, S5_NDIRECT_BLOCKS * sizeof(int));
if ((S5_TYPE_CHR == type) || (S5_TYPE_BLK == type))
inode->s5_indirect_block = devid;
else
inode->s5_indirect_block = 0;
s5_dirty_inode(s5fs, inode);
unlock_s5(s5fs);
return ret;
}
/*
* 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;
*/
}
/*
* 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)
{
s5_super_t *s = fs->s5f_super;
lock_s5(fs);
KASSERT(S5_NBLKS_PER_FNODE > s->s5s_nfree);
int free_block_num;
if (s->s5s_nfree == 0){
free_block_num = s->s5s_free_blocks[S5_NBLKS_PER_FNODE - 1];
if (free_block_num == -1){
unlock_s5(fs);
return -ENOSPC;
}
/* get the pframe from which we'll replenish our list of free block nums */
pframe_t *next_free_blocks;
KASSERT(fs->s5f_bdev);
int get_res = pframe_get(&fs->s5f_bdev->bd_mmobj, free_block_num,
&next_free_blocks);
if (get_res < 0){
dbg(DBG_S5FS, "error in pframe_get\n");
unlock_s5(fs);
return get_res;
}
memcpy((void *)(s->s5s_free_blocks), next_free_blocks->pf_addr,
S5_NBLKS_PER_FNODE * sizeof(int));
s->s5s_nfree = S5_NBLKS_PER_FNODE - 1;
} else {
free_block_num = s->s5s_free_blocks[--s->s5s_nfree];
}
s5_dirty_super(fs);
unlock_s5(fs);
return free_block_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);
}