/*
* 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;
}
/*
* 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;
}
/*
* 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;
}
/*
* 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);
}
/*
* 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;
}
}
}
/*
* 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;
}
/*
* This gets called by _pt_fault_handler in mm/pagetable.c The
* calling function has already done a lot of error checking for
* us. In particular it has checked that we are not page faulting
* while in kernel mode. Make sure you understand why an
* unexpected page fault in kernel mode is bad in Weenix. You
* should probably read the _pt_fault_handler function to get a
* sense of what it is doing.
*
* Before you can do anything you need to find the vmarea that
* contains the address that was faulted on. Make sure to check
* the permissions on the area to see if the process has
* permission to do [cause]. If either of these checks does not
* pass kill the offending process, setting its exit status to
* EFAULT (normally we would send the SIGSEGV signal, however
* Weenix does not support signals).
*
* Now it is time to find the correct page (don't forget
* about shadow objects, especially copy-on-write magic!). Make
* sure that if the user writes to the page it will be handled
* correctly.
*
* Finally call pt_map to have the new mapping placed into the
* appropriate page table.
*
* @param vaddr the address that was accessed to cause the fault
*
* @param cause this is the type of operation on the memory
* address which caused the fault, possible values
* can be found in pagefault.h
*/
void handle_pagefault(uintptr_t vaddr, uint32_t cause) {
/*NOT_YET_IMPLEMENTED("VM: handle_pagefault");*/
vmarea_t *vma;
pframe_t *pf;
int pflags = PD_PRESENT | PD_USER;
int writeflag = 0;
dbg(DBG_PRINT, "(GRADING3F)\n");
if ((vma = vmmap_lookup(curproc->p_vmmap, ADDR_TO_PN(vaddr))) == NULL) {
dbg(DBG_PRINT, "(GRADING3C 1)\n");
proc_kill(curproc, EFAULT);
return;
}
/*
if (vma->vma_prot & PROT_NONE) {
dbg(DBG_ERROR, "(GRADING3 3)\n");
proc_kill(curproc, EFAULT);
return;
}*/
if (!((cause & FAULT_WRITE) || (cause & FAULT_EXEC))
&& !(vma->vma_prot & PROT_READ)) {
dbg(DBG_PRINT, "(GRADING3D 3)\n");
proc_kill(curproc, EFAULT);
return;
}
if ((cause & FAULT_WRITE) && !(vma->vma_prot & PROT_WRITE)) {
dbg(DBG_PRINT, "(GRADING3D 3)\n");
proc_kill(curproc, EFAULT);
return;
}/*
if ((cause & FAULT_EXEC) && !(vma->vma_prot & PROT_EXEC)) {
dbg(DBG_ERROR, "(GRADING3 6)\n");
proc_kill(curproc, EFAULT);
return;;
}*/
if (cause & FAULT_WRITE) {
dbg(DBG_PRINT, "(GRADING3F)\n");
writeflag = 1;
}
if (pframe_lookup(vma->vma_obj,
ADDR_TO_PN(vaddr) - vma->vma_start + vma->vma_off, writeflag, &pf) < 0) {
dbg(DBG_PRINT, "(GRADING3D 4)\n");
proc_kill(curproc, EFAULT);
return;
}
if (cause & FAULT_WRITE) {
pframe_pin(pf);
dbg(DBG_PRINT, "(GRADING3F)\n");
pframe_dirty(pf);
/*
if ( < 0) {
dbg(DBG_ERROR, "(GRADING3 10)\n");
pframe_unpin(pf);
proc_kill(curproc, EFAULT);
return;
}*/
pframe_unpin(pf);
pflags |= PD_WRITE;
}
pt_map(curproc->p_pagedir, (uintptr_t) PAGE_ALIGN_DOWN(vaddr),
pt_virt_to_phys((uintptr_t) pf->pf_addr), pflags, pflags);
}
/*
* 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;
}
/*
* 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");
}