Пример #1
0
/*
 * 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;
}
Пример #2
0
/*
 * 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);
}
Пример #3
0
/*
 * 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);
}
Пример #4
0
/*
 * 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;
}
Пример #5
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;
    }
}
Пример #6
0
/*
 * 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;
}
Пример #7
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;
        */
}
Пример #8
0
/*
 * 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;
}
Пример #9
0
/*
 * 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);
}
Пример #10
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)
{
    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;
}
Пример #11
0
/* 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;
}
Пример #12
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;
}
Пример #13
0
/*
 * 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");*/
	vmmap_t *map = curproc->p_vmmap;
	dbginfo(DBG_ERROR, proc_info, curproc);
	dbginfo(DBG_ERROR, proc_list_info, NULL);
	if(vaddr == NULL){
	}	
	vmarea_t *vma =	vmmap_lookup(map, ADDR_TO_PN(vaddr));
	
	/*uintptr_t pagenum = PAGE_OFFSET(vaddr);*/
	if(vma == NULL ||  !(cause & FAULT_USER)){
		/*XXX permission checks*/
		curproc->p_status = EFAULT;
		proc_kill(curproc, EFAULT);
	}
	pframe_t *pf;
	uintptr_t pagenum =  ADDR_TO_PN(vaddr) - vma->vma_start+vma->vma_off;
	/*XXX handle shadow objects*/	
	/*
	int forWrite = 0;
	if(cause & FAULT_WRITE){
		forWrite = 1;
	}
	*/		
	/*
	if(vma->vma_obj->mmo_shadowed != NULL){
		shadow_lookuppage(vma->vma_obj->mmo_shadowed, pagenum, forWrite,&pf);
	}else{
	*/
		pframe_get(vma->vma_obj, pagenum, &pf);
	/*}*/
	uintptr_t paddr = pt_virt_to_phys((uintptr_t)pf->pf_addr);
	uintptr_t pdflags = PD_PRESENT | PD_WRITE | PD_USER;
	uintptr_t ptflags = PT_PRESENT | PT_WRITE | PT_USER;
	/*XXX tlb flush?*/
	pt_map(curproc->p_pagedir,(uintptr_t)PAGE_ALIGN_DOWN(vaddr), paddr, pdflags, ptflags);

}
Пример #14
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");
}
Пример #15
0
/*
 * 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;
}
Пример #16
0
/*
 * 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;
}
Пример #17
0
/*
 * 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;
}
Пример #18
0
/*
 * 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");
}
Пример #19
0
/*
 * 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);
}
Пример #20
0
/*
 * 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;
        }
    }
}
Пример #21
0
/*
 * 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;
}
Пример #22
0
/*
 * 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;
        */
}
Пример #23
0
/*
 * 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;
}
Пример #24
0
/*
 * 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;
}
Пример #25
0
/*
 * 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;
}
Пример #26
0
/*
 * 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;
}