286 lines
		
	
	
		
			7.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			286 lines
		
	
	
		
			7.6 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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| 
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| #include <minix/vfsif.h>
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| 
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| PRIVATE int dummyproc;
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| 
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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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| 
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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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| 
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|   dev = fs_m_in.REQ_DEV;   /* Device number */
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| 
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|   ip = alloc_inode(fs_dev, ALL_MODES | I_CHAR_SPECIAL);
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| 
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|   if (ip == NIL_INODE) return err_code;
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| 
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|   ip->i_zone[0] = dev;
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| 
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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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| 
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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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| 
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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[NR_IOREQS];
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| 
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| 	/* Number of grants allocated in vector I/O. */
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| 	*vec_grants = 0;
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| 
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| 	/* Driver can handle it - change request to a safe one. */
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| 
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| 	*gid = GRANT_INVALID;
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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| /*===========================================================================*
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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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| 
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|   	cpf_revoke(gid);
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| 
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| 	for(j = 0; j < gids_size; j++)
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| 		cpf_revoke(gids[j]);
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| 
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| 	return;
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| }
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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[NR_IOREQS];
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|   endpoint_t driver_e;
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| 
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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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|   
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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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|   
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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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|   
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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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| 
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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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| 
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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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| 
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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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| 
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|   /* Call the task. */
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|   r = sendrec(driver_e, &m);
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| 
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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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|   
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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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| 
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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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| 
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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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| 
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|   return(m.REP_STATUS);
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| }
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| 
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| 
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| 
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| 
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| 
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| 
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| 
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| 
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