root/kern/fs/sfs/sfs_io.c

/* [<][>][^][v][top][bottom][index][help] */

DEFINITIONS

This source file includes following definitions.
  1. sfs_rwblock
  2. sfs_rblock
  3. sfs_wblock

   1 /*
   2  * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
   3  *      The President and Fellows of Harvard College.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29 
  30 #include <types.h>
  31 #include <kern/errno.h>
  32 #include <lib.h>
  33 #include <uio.h>
  34 #include <vfs.h>
  35 #include <device.h>
  36 #include <sfs.h>
  37 
  38 ////////////////////////////////////////////////////////////
  39 //
  40 // Basic block-level I/O routines
  41 //
  42 // Note: sfs_rblock is used to read the superblock
  43 // early in mount, before sfs is fully (or even mostly)
  44 // initialized, and so may not use anything from sfs
  45 // except sfs_device.
  46 
  47 int
  48 sfs_rwblock(struct sfs_fs *sfs, struct uio *uio)
  49 {
  50         int result;
  51         int tries=0;
  52 
  53         KASSERT(vfs_biglock_do_i_hold());
  54 
  55         DEBUG(DB_SFS, "sfs: %s %llu\n", 
  56               uio->uio_rw == UIO_READ ? "read" : "write",
  57               uio->uio_offset / SFS_BLOCKSIZE);
  58 
  59  retry:
  60         result = sfs->sfs_device->d_io(sfs->sfs_device, uio);
  61         if (result == EINVAL) {
  62                 /*
  63                  * This means the sector we requested was out of range,
  64                  * or the seek address we gave wasn't sector-aligned,
  65                  * or a couple of other things that are our fault.
  66                  */
  67                 panic("sfs: d_io returned EINVAL\n");
  68         }
  69         if (result == EIO) {
  70                 if (tries == 0) {
  71                         tries++;
  72                         kprintf("sfs: block %llu I/O error, retrying\n",
  73                                 uio->uio_offset / SFS_BLOCKSIZE);
  74                         goto retry;
  75                 }
  76                 else if (tries < 10) {
  77                         tries++;
  78                         goto retry;
  79                 }
  80                 else {
  81                         kprintf("sfs: block %llu I/O error, giving up after "
  82                                 "%d retries\n",
  83                                 uio->uio_offset / SFS_BLOCKSIZE, tries);
  84                 }
  85         }
  86         return result;
  87 }
  88 
  89 int
  90 sfs_rblock(struct sfs_fs *sfs, void *data, uint32_t block)
  91 {
  92         struct iovec iov;
  93         struct uio ku;
  94 
  95         SFSUIO(&iov, &ku, data, block, UIO_READ);
  96         return sfs_rwblock(sfs, &ku);
  97 }
  98 
  99 int
 100 sfs_wblock(struct sfs_fs *sfs, void *data, uint32_t block)
 101 {
 102         struct iovec iov;
 103         struct uio ku;
 104 
 105         SFSUIO(&iov, &ku, data, block, UIO_WRITE);
 106         return sfs_rwblock(sfs, &ku);
 107 }

/* [<][>][^][v][top][bottom][index][help] */