示例#1
0
文件: cache.c 项目: Spenser309/CS551
/*===========================================================================*
 *				rw_scattered				     *
 *===========================================================================*/
PUBLIC void rw_scattered(
  dev_t dev,			/* major-minor device number */
  struct buf **bufq,		/* pointer to array of buffers */
  int bufqsize,		/* number of buffers */
  int rw_flag 			/* READING or WRITING */
)
{
/* Read or write scattered data from a device. */

  register struct buf *bp;
  int gap;
  register int i;
  register iovec_t *iop;
  static iovec_t *iovec = NULL;
  int j, r;

  STATICINIT(iovec, NR_IOREQS);

  /* (Shell) sort buffers on b_blocknr. */
  gap = 1;
  do
	gap = 3 * gap + 1;
  while (gap <= bufqsize);
  while (gap != 1) {
	gap /= 3;
	for (j = gap; j < bufqsize; j++) {
		for (i = j - gap;
		     i >= 0 && bufq[i]->b_blocknr > bufq[i + gap]->b_blocknr;
		     i -= gap) {
			bp = bufq[i];
			bufq[i] = bufq[i + gap];
			bufq[i + gap] = bp;
		}
	}
  }

  /* Set up I/O vector and do I/O.  The result of dev_io is OK if everything
   * went fine, otherwise the error code for the first failed transfer.
   */
  while (bufqsize > 0) {
	for (j = 0, iop = iovec; j < NR_IOREQS && j < bufqsize; j++, iop++) {
		bp = bufq[j];
		if (bp->b_blocknr != (block_t) bufq[0]->b_blocknr + j) break;
		iop->iov_addr = (vir_bytes) bp->b_data;
		iop->iov_size = (vir_bytes) fs_block_size;
	}
	r = block_dev_io(rw_flag == WRITING ? MFS_DEV_SCATTER : MFS_DEV_GATHER,
		dev, SELF_E, iovec,
		mul64u(bufq[0]->b_blocknr, fs_block_size), j);

	/* Harvest the results.  Dev_io reports the first error it may have
	 * encountered, but we only care if it's the first block that failed.
	 */
	for (i = 0, iop = iovec; i < j; i++, iop++) {
		bp = bufq[i];
		if (iop->iov_size != 0) {
			/* Transfer failed. An error? Do we care? */
			if (r != OK && i == 0) {
				printf(
				"fs: I/O error on device %d/%d, block %lu\n",
					major(dev), minor(dev), bp->b_blocknr);
				bp->b_dev = NO_DEV;	/* invalidate block */
				vm_forgetblocks();
			}
			break;
		}
		if (rw_flag == READING) {
			bp->b_dev = dev;	/* validate block */
			put_block(bp, PARTIAL_DATA_BLOCK);
		} else {
			bp->b_dirt = CLEAN;
		}
	}
	bufq += i;
	bufqsize -= i;
	if (rw_flag == READING) {
		/* Don't bother reading more than the device is willing to
		 * give at this time.  Don't forget to release those extras.
		 */
		while (bufqsize > 0) {
			put_block(*bufq++, PARTIAL_DATA_BLOCK);
			bufqsize--;
		}
	}
	if (rw_flag == WRITING && i == 0) {
		/* We're not making progress, this means we might keep
		 * looping. Buffers remain dirty if un-written. Buffers are
		 * lost if invalidate()d or LRU-removed while dirty. This
		 * is better than keeping unwritable blocks around forever..
		 */
		break;
	}
  }
}
示例#2
0
文件: mount.c 项目: DragonQuan/minix3
/*===========================================================================*
 *				fs_readsuper				     *
 *===========================================================================*/
PUBLIC int fs_readsuper()
{
/* This function reads the superblock of the partition, gets the root inode
 * and sends back the details of them. Note, that the FS process does not
 * know the index of the vmnt object which refers to it, whenever the pathname
 * lookup leaves a partition an ELEAVEMOUNT error is transferred back
 * so that the VFS knows that it has to find the vnode on which this FS
 * process' partition is mounted on.
 */
  struct inode *root_ip;
  cp_grant_id_t label_gid;
  size_t label_len;
  int r = OK;
  int readonly, isroot;
  u32_t mask;

  fs_dev    = fs_m_in.REQ_DEV;
  label_gid = fs_m_in.REQ_GRANT;
  label_len = fs_m_in.REQ_PATH_LEN;
  readonly  = (fs_m_in.REQ_FLAGS & REQ_RDONLY) ? 1 : 0;
  isroot    = (fs_m_in.REQ_FLAGS & REQ_ISROOT) ? 1 : 0;

  if (label_len > sizeof(fs_dev_label))
	return(EINVAL);

  r = sys_safecopyfrom(fs_m_in.m_source, label_gid, 0,
		       (vir_bytes)fs_dev_label, label_len, D);
  if (r != OK) {
	printf("%s:%d fs_readsuper: safecopyfrom failed: %d\n",
	       __FILE__, __LINE__, r);
	return(EINVAL);
  }

  /* Map the driver label for this major. */
  bdev_driver(fs_dev, fs_dev_label);

  /* Open the device the file system lives on. */
  if (bdev_open(fs_dev, readonly ? R_BIT : (R_BIT|W_BIT)) != OK) {
        return(EINVAL);
  }

  /* Fill in the super block. */
  STATICINIT(superblock, 1);
  if (!superblock)
	panic("Can't allocate memory for superblock.");
  superblock->s_dev = fs_dev;	/* read_super() needs to know which dev */
  r = read_super(superblock);

  /* Is it recognized as a Minix filesystem? */
  if (r != OK) {
	superblock->s_dev = NO_DEV;
	bdev_close(fs_dev);
	return(r);
  }

  if (superblock->s_rev_level != EXT2_GOOD_OLD_REV) {
	struct super_block *sp = superblock; /* just shorter name */
	mask = ~SUPPORTED_INCOMPAT_FEATURES;
	if (HAS_INCOMPAT_FEATURE(sp, mask)) {
		if (HAS_INCOMPAT_FEATURE(sp, INCOMPAT_COMPRESSION & mask))
			printf("ext2: fs compression is not supported by server\n");
		if (HAS_INCOMPAT_FEATURE(sp, INCOMPAT_FILETYPE & mask))
			printf("ext2: fs in dir filetype is not supported by server\n");
		if (HAS_INCOMPAT_FEATURE(sp, INCOMPAT_RECOVER & mask))
			printf("ext2: fs recovery is not supported by server\n");
		if (HAS_INCOMPAT_FEATURE(sp, INCOMPAT_JOURNAL_DEV & mask))
			printf("ext2: fs journal dev is not supported by server\n");
		if (HAS_INCOMPAT_FEATURE(sp, INCOMPAT_META_BG & mask))
			printf("ext2: fs meta bg is not supported by server\n");
		return(EINVAL);
	}
	mask = ~SUPPORTED_RO_COMPAT_FEATURES;
	if (HAS_RO_COMPAT_FEATURE(sp, mask)) {
		if (HAS_RO_COMPAT_FEATURE(sp, RO_COMPAT_SPARSE_SUPER & mask)) {
			printf("ext2: sparse super is not supported by server, \
				remount read-only\n");
		}
		if (HAS_RO_COMPAT_FEATURE(sp, RO_COMPAT_LARGE_FILE & mask)) {
			printf("ext2: large files are not supported by server, \
				remount read-only\n");
		}
		if (HAS_RO_COMPAT_FEATURE(sp, RO_COMPAT_BTREE_DIR & mask)) {
			printf("ext2: dir's btree is not supported by server, \
				remount read-only\n");
		}
		return(EINVAL);
	}
  }

  if (superblock->s_state == EXT2_ERROR_FS) {
	printf("ext2: filesystem wasn't cleanly unmounted previous time\n");
        superblock->s_dev = NO_DEV;
	bdev_close(fs_dev);
	return(EINVAL);
  }


  set_blocksize(superblock->s_block_size,
  	superblock->s_blocks_count,
	superblock->s_free_blocks_count,
	major(fs_dev));

  /* Get the root inode of the mounted file system. */
  if ( (root_ip = get_inode(fs_dev, ROOT_INODE)) == NULL)  {
	printf("ext2: couldn't get root inode\n");
	superblock->s_dev = NO_DEV;
	bdev_close(fs_dev);
	return(EINVAL);
  }

  if (root_ip != NULL && root_ip->i_mode == 0) {
	printf("%s:%d zero mode for root inode?\n", __FILE__, __LINE__);
	put_inode(root_ip);
	superblock->s_dev = NO_DEV;
	bdev_close(fs_dev);
	return(EINVAL);
  }

  if (root_ip != NULL && (root_ip->i_mode & I_TYPE) != I_DIRECTORY) {
	printf("%s:%d root inode has wrong type, it's not a DIR\n",
		 __FILE__, __LINE__);
	put_inode(root_ip);
	superblock->s_dev = NO_DEV;
	bdev_close(fs_dev);
	return(EINVAL);
  }

  superblock->s_rd_only = readonly;
  superblock->s_is_root = isroot;

  if (!readonly) {
	superblock->s_state = EXT2_ERROR_FS;
	superblock->s_mnt_count++;
	superblock->s_mtime = clock_time();
	write_super(superblock); /* Commit info, we just set above */
  }

  /* Root inode properties */
  fs_m_out.RES_INODE_NR = root_ip->i_num;
  fs_m_out.RES_MODE = root_ip->i_mode;
  fs_m_out.RES_FILE_SIZE_LO = root_ip->i_size;
  fs_m_out.RES_UID = root_ip->i_uid;
  fs_m_out.RES_GID = root_ip->i_gid;

  fs_m_out.RES_CONREQS = 1;	/* We can handle only 1 request at a time */

  return(r);
}
示例#3
0
文件: cache.c 项目: 0xenvision/minix
/*===========================================================================*
 *				rw_scattered				     *
 *===========================================================================*/
void rw_scattered(
  dev_t dev,			/* major-minor device number */
  struct buf **bufq,		/* pointer to array of buffers */
  int bufqsize,		/* number of buffers */
  int rw_flag 			/* READING or WRITING */
)
{
/* Read or write scattered data from a device. */

  register struct buf *bp;
  int gap;
  register int i;
  register iovec_t *iop;
  static iovec_t *iovec = NULL;
  u64_t pos;
  int j, r;

  STATICINIT(iovec, NR_IOREQS);
  assert(bufq != NULL);

  /* (Shell) sort buffers on b_blocknr. */
  gap = 1;
  do
	gap = 3 * gap + 1;
  while (gap <= bufqsize);
  while (gap != 1) {
	gap /= 3;
	for (j = gap; j < bufqsize; j++) {
		for (i = j - gap;
		     i >= 0 && bufq[i]->b_blocknr > bufq[i + gap]->b_blocknr;
		     i -= gap) {
			bp = bufq[i];
			bufq[i] = bufq[i + gap];
			bufq[i + gap] = bp;
		}
	}
  }

  /* Set up I/O vector and do I/O.  The result of dev_io is OK if everything
   * went fine, otherwise the error code for the first failed transfer.
   */
  while (bufqsize > 0) {
	for (j = 0, iop = iovec; j < NR_IOREQS && j < bufqsize; j++, iop++) {
		bp = bufq[j];
		if (bp->b_blocknr != (block_t) bufq[0]->b_blocknr + j) break;
		iop->iov_addr = (vir_bytes) bp->b_data;
		iop->iov_size = (vir_bytes) fs_block_size;
	}
	pos = mul64u(bufq[0]->b_blocknr, fs_block_size);
	if (rw_flag == READING)
		r = bdev_gather(dev, pos, iovec, j, BDEV_NOFLAGS);
	else
		r = bdev_scatter(dev, pos, iovec, j, BDEV_NOFLAGS);

	/* Harvest the results.  The driver may have returned an error, or it
	 * may have done less than what we asked for.
	 */
	if (r < 0) {
		printf("ext2: I/O error %d on device %d/%d, block %u\n",
			r, major(dev), minor(dev), bufq[0]->b_blocknr);
	}
	for (i = 0; i < j; i++) {
		bp = bufq[i];
		if (r < (ssize_t) fs_block_size) {
			/* Transfer failed. */
			if (i == 0) {
				bp->b_dev = NO_DEV;	/* invalidate block */
				vm_forgetblocks();
			}
			break;
		}
		if (rw_flag == READING) {
			bp->b_dev = dev;	/* validate block */
			put_block(bp, PARTIAL_DATA_BLOCK);
		} else {
			bp->b_dirt = CLEAN;
		}
		r -= fs_block_size;
	}
	bufq += i;
	bufqsize -= i;
	if (rw_flag == READING) {
		/* Don't bother reading more than the device is willing to
		 * give at this time.  Don't forget to release those extras.
		 */
		while (bufqsize > 0) {
			put_block(*bufq++, PARTIAL_DATA_BLOCK);
			bufqsize--;
		}
	}
	if (rw_flag == WRITING && i == 0) {
		/* We're not making progress, this means we might keep
		 * looping. Buffers remain dirty if un-written. Buffers are
		 * lost if invalidate()d or LRU-removed while dirty. This
		 * is better than keeping unwritable blocks around forever..
		 */
		break;
	}
  }
}