390 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			390 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
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#include "fs.h"
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#include <fcntl.h>
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#include <assert.h>
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#include <minix/callnr.h>
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#include <minix/com.h>
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#include <minix/endpoint.h>
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#include <minix/ioctl.h>
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#include <minix/safecopies.h>
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#include <minix/u64.h>
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#include <string.h>
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#include "inode.h"
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#include "super.h"
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#include "const.h"
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#include "drivers.h"
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#include <minix/vfsif.h>
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PRIVATE int dummyproc;
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FORWARD _PROTOTYPE( int safe_io_conversion, (endpoint_t,
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  cp_grant_id_t *, int *, cp_grant_id_t *, int, endpoint_t *,
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  void **, int *, vir_bytes));
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FORWARD _PROTOTYPE( void safe_io_cleanup, (cp_grant_id_t, cp_grant_id_t *,
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	int));
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FORWARD _PROTOTYPE( int gen_opcl, (endpoint_t driver_e, int op,
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				Dev_t dev, int proc_e, int flags)	);
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FORWARD _PROTOTYPE( int gen_io, (int task_nr, message *mess_ptr)	);
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/*===========================================================================*
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 *				fs_clone_opcl   			     *
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 *===========================================================================*/
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PUBLIC int fs_clone_opcl(void)
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{
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 /* A new minor device number has been returned.
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  * Create a temporary device file to hold it. 
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  */
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  struct inode *ip;
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  dev_t dev; 
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  dev = fs_m_in.REQ_DEV;   /* Device number */
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  ip = alloc_inode(fs_dev, ALL_MODES | I_CHAR_SPECIAL);
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  if (ip == NIL_INODE) return err_code;
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  ip->i_zone[0] = dev;
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  fs_m_out.m_source = ip->i_dev;
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  fs_m_out.RES_INODE_NR = ip->i_num;
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  fs_m_out.RES_MODE = ip->i_mode;
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  return OK;
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}
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/*===========================================================================*
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 *				fs_new_driver   			     *
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 *===========================================================================*/
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PUBLIC int fs_new_driver(void)
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{
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 /* New driver endpoint for this device */
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  driver_endpoints[(fs_m_in.REQ_DEV >> MAJOR) & BYTE].driver_e =
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      fs_m_in.REQ_DRIVER_E;
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  return OK;
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}
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/*===========================================================================*
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 *				safe_io_conversion			     *
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 *===========================================================================*/
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PRIVATE int safe_io_conversion(driver, gid, op, gids, gids_size,
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	io_ept, buf, vec_grants, bytes)
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endpoint_t driver;
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cp_grant_id_t *gid;
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int *op;
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cp_grant_id_t *gids;
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int gids_size;
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endpoint_t *io_ept;
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void **buf;
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int *vec_grants;
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vir_bytes bytes;
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{
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	int access = 0, size;
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	int j;
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	iovec_t *v;
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	static iovec_t *new_iovec;
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	STATICINIT(new_iovec, NR_IOREQS);
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	/* Number of grants allocated in vector I/O. */
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	*vec_grants = 0;
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	/* Driver can handle it - change request to a safe one. */
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	*gid = GRANT_INVALID;
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	switch(*op) {
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		case MFS_DEV_READ:
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		case MFS_DEV_WRITE:
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			/* Change to safe op. */
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			*op = *op == MFS_DEV_READ ? DEV_READ_S : DEV_WRITE_S;
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			if((*gid=cpf_grant_direct(driver, (vir_bytes) *buf, 
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				bytes, *op == DEV_READ_S ? CPF_WRITE : 
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				CPF_READ)) < 0) {
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				panic(__FILE__,
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				 "cpf_grant_magic of buffer failed\n", NO_NUM);
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			}
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			break;
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		case MFS_DEV_GATHER:
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		case MFS_DEV_SCATTER:
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			/* Change to safe op. */
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			*op = *op == MFS_DEV_GATHER ?
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				DEV_GATHER_S : DEV_SCATTER_S;
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			/* Grant access to my new i/o vector. */
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			if((*gid = cpf_grant_direct(driver,
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			  (vir_bytes) new_iovec, bytes * sizeof(iovec_t),
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			  CPF_READ | CPF_WRITE)) < 0) {
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				panic(__FILE__,
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				"cpf_grant_direct of vector failed", NO_NUM);
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			}
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			v = (iovec_t *) *buf;
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			/* Grant access to i/o buffers. */
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			for(j = 0; j < bytes; j++) {
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			   if(j >= NR_IOREQS) 
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				panic(__FILE__, "vec too big", bytes);
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			   new_iovec[j].iov_addr = gids[j] =
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			     cpf_grant_direct(driver, (vir_bytes)
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			     v[j].iov_addr, v[j].iov_size,
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			     *op == DEV_GATHER_S ? CPF_WRITE : CPF_READ);
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			   if(!GRANT_VALID(gids[j])) {
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				panic(__FILE__, "mfs: grant to iovec buf failed",
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				 NO_NUM);
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			   }
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			   new_iovec[j].iov_size = v[j].iov_size;
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			   (*vec_grants)++;
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			}
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			/* Set user's vector to the new one. */
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			*buf = new_iovec;
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			break;
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	}
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	/* If we have converted to a safe operation, I/O
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	 * endpoint becomes FS if it wasn't already.
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	 */
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	if(GRANT_VALID(*gid)) {
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		*io_ept = SELF_E;
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		return 1;
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	}
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	/* Not converted to a safe operation (because there is no
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	 * copying involved in this operation).
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	 */
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	return 0;
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}
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/*===========================================================================*
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 *			safe_io_cleanup					     *
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 *===========================================================================*/
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PRIVATE void safe_io_cleanup(gid, gids, gids_size)
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cp_grant_id_t gid;
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cp_grant_id_t *gids;
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int gids_size;
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{
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/* Free resources (specifically, grants) allocated by safe_io_conversion(). */
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	int j;
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  	cpf_revoke(gid);
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	for(j = 0; j < gids_size; j++)
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		cpf_revoke(gids[j]);
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	return;
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}
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/*===========================================================================*
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 *			block_dev_io					     *
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 *===========================================================================*/
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PUBLIC int block_dev_io(op, dev, proc_e, buf, pos, bytes, flags)
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int op;				/* MFS_DEV_READ, MFS_DEV_WRITE, etc. */
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dev_t dev;			/* major-minor device number */
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int proc_e;			/* in whose address space is buf? */
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void *buf;			/* virtual address of the buffer */
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u64_t pos;			/* byte position */
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int bytes;			/* how many bytes to transfer */
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int flags;			/* special flags, like O_NONBLOCK */
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{
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/* Read or write from a device.  The parameter 'dev' tells which one. */
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  struct dmap *dp;
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  int r, safe;
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  message m;
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  iovec_t *v;
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  cp_grant_id_t gid = GRANT_INVALID;
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  int vec_grants;
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  int op_used;
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  void *buf_used;
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  static cp_grant_id_t *gids;
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  endpoint_t driver_e;
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  STATICINIT(gids, NR_IOREQS);
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  /* Determine driver endpoint for this device */
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  driver_e = driver_endpoints[(dev >> MAJOR) & BYTE].driver_e;
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  /* See if driver is roughly valid. */
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  if (driver_e == NONE) {
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      printf("MFS(%d) block_dev_io: no driver for dev %x\n", SELF_E, dev);
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      return EDSTDIED;
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  }
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  /* The io vector copying relies on this I/O being for FS itself. */
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  if(proc_e != SELF_E) {
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      printf("MFS(%d) doing block_dev_io for non-self %d\n", SELF_E, proc_e);
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      panic(__FILE__, "doing block_dev_io for non-self", proc_e);
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  }
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  /* By default, these are right. */
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  m.IO_ENDPT = proc_e;
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  m.ADDRESS  = buf;
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  buf_used = buf;
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  /* Convert parameters to 'safe mode'. */
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  op_used = op;
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  safe = safe_io_conversion(driver_e, &gid,
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          &op_used, gids, NR_IOREQS, &m.IO_ENDPT, &buf_used,
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          &vec_grants, bytes);
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  /* Set up rest of the message. */
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  if (safe) m.IO_GRANT = (char *) gid;
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  m.m_type   = op_used;
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  m.DEVICE   = (dev >> MINOR) & BYTE;
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  m.POSITION = ex64lo(pos);
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  m.COUNT    = bytes;
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  m.HIGHPOS  = ex64hi(pos);
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  /* Call the task. */
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  r = sendrec(driver_e, &m);
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  /* As block I/O never SUSPENDs, safe cleanup must be done whether
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   * the I/O succeeded or not. */
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  if (safe) safe_io_cleanup(gid, gids, vec_grants);
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  /* RECOVERY:
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   * - send back dead driver number
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   * - VFS unmaps it, waits for new driver
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   * - VFS sends the new driver endp for the FS proc and the request again 
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   */
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  if (r != OK) {
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      if (r == EDEADSRCDST || r == EDSTDIED || r == ESRCDIED) {
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          printf("MFS(%d) dead driver %d\n", SELF_E, driver_e);
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          driver_endpoints[(dev >> MAJOR) & BYTE].driver_e = NONE;
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          return r;
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          /*dmap_unmap_by_endpt(task_nr);    <- in the VFS proc...  */
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      }
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      else if (r == ELOCKED) {
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          printf("MFS(%d) ELOCKED talking to %d\n", SELF_E, driver_e);
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          return r;
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      }
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      else 
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          panic(__FILE__,"call_task: can't send/receive", r);
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  } 
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  else {
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      /* Did the process we did the sendrec() for get a result? */
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      if (m.REP_ENDPT != proc_e) {
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          printf("MFS(%d) strange device reply from %d, type = %d, proc = %d (not %d) (2) ignored\n", SELF_E, m.m_source, m.m_type, proc_e, m.REP_ENDPT);
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          r = EIO;
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      }
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  }
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  /* Task has completed.  See if call completed. */
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  if (m.REP_STATUS == SUSPEND) {
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      panic(__FILE__, "MFS block_dev_io: driver returned SUSPEND", NO_NUM);
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  }
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  if(buf != buf_used && r == OK) {
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      memcpy(buf, buf_used, bytes * sizeof(iovec_t));
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  }
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  return(m.REP_STATUS);
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}
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/*===========================================================================*
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 *				dev_open				     *
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 *===========================================================================*/
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PUBLIC int dev_open(driver_e, dev, proc, flags)
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endpoint_t driver_e;
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dev_t dev;			/* device to open */
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int proc;			/* process to open for */
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int flags;			/* mode bits and flags */
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{
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  int major, r;
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  /* Determine the major device number call the device class specific
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   * open/close routine.  (This is the only routine that must check the
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   * device number for being in range.  All others can trust this check.)
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   */
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  major = (dev >> MAJOR) & BYTE;
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  if (major >= NR_DEVICES) major = 0;
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  r = gen_opcl(driver_e, DEV_OPEN, dev, proc, flags);
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  if (r == SUSPEND) panic(__FILE__,"suspend on open from", NO_NUM);
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  return(r);
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}
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/*===========================================================================*
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 *				dev_close				     *
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 *===========================================================================*/
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PUBLIC void dev_close(driver_e, dev)
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endpoint_t driver_e;
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dev_t dev;			/* device to close */
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{
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  (void) gen_opcl(driver_e, DEV_CLOSE, dev, 0, 0);
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}
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/*===========================================================================*
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 *				gen_opcl				     *
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 *===========================================================================*/
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PRIVATE int gen_opcl(driver_e, op, dev, proc_e, flags)
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endpoint_t driver_e;
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int op;				/* operation, DEV_OPEN or DEV_CLOSE */
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dev_t dev;			/* device to open or close */
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int proc_e;			/* process to open/close for */
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int flags;			/* mode bits and flags */
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{
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/* Called from the dmap struct in table.c on opens & closes of special files.*/
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  message dev_mess;
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  dev_mess.m_type   = op;
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  dev_mess.DEVICE   = (dev >> MINOR) & BYTE;
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  dev_mess.IO_ENDPT = proc_e;
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  dev_mess.COUNT    = flags;
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  /* Call the task. */
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  gen_io(driver_e, &dev_mess);
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  return(dev_mess.REP_STATUS);
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}
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/*===========================================================================*
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 *				gen_io					     *
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 *===========================================================================*/
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PRIVATE int gen_io(task_nr, mess_ptr)
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int task_nr;			/* which task to call */
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message *mess_ptr;		/* pointer to message for task */
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{
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/* All file system I/O ultimately comes down to I/O on major/minor device
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 * pairs.  These lead to calls on the following routines via the dmap table.
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 */
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  int r, proc_e;
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  proc_e = mess_ptr->IO_ENDPT;
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  r = sendrec(task_nr, mess_ptr);
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	if (r != OK) {
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		if (r == EDEADSRCDST || r == EDSTDIED || r == ESRCDIED) {
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			printf("fs: dead driver %d\n", task_nr);
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			panic(__FILE__, "should handle crashed drivers",
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				NO_NUM);
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			/* dmap_unmap_by_endpt(task_nr); */
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			return r;
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		}
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		if (r == ELOCKED) {
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			printf("fs: ELOCKED talking to %d\n", task_nr);
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			return r;
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		}
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		panic(__FILE__,"call_task: can't send/receive", r);
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	}
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  	/* Did the process we did the sendrec() for get a result? */
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  	if (mess_ptr->REP_ENDPT != proc_e) {
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		printf(
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		"fs: strange device reply from %d, type = %d, proc = %d (not %d) (2) ignored\n",
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			mess_ptr->m_source,
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			mess_ptr->m_type,
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			proc_e,
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			mess_ptr->REP_ENDPT);
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		return EIO;
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	}
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  return OK;
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}
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