BIO Usage Error or Conflicting Designs

[Andre Hedrick <andre@linuxdiskcert.org>]

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Jens,

Below is a single sector read using ACB.
If I do not use the code inside "#ifdef USEBIO" and run UP/SMP but no
highmem, it runs and works like a charm.  It is also 100% unchanged code
from what is in 2.4 patches.  The attached oops is generate under
SMP without highmem and running the USEBIO code.

CONFIG_NOHIGHMEM=y
# CONFIG_HIGHMEM4G is not set
# CONFIG_HIGHMEM64G is not set

Regards,

Andre Hedrick
Linux Disk Certification Project                Linux ATA Development


/*
 * Handler for command with PIO data-in phase
 */
ide_startstop_t task_in_intr (ide_drive_t *drive)
{
  byte stat               = GET_STAT();
  byte io_32bit           = drive->io_32bit;
  struct request *rq      = HWGROUP(drive)->rq;
  char *pBuf              = NULL;

  if (!OK_STAT(stat,DATA_READY,BAD_R_STAT)) {
    if (stat & (ERR_STAT|DRQ_STAT)) {
      return ide_error(drive, "task_in_intr", stat);
    }
    if (!(stat & BUSY_STAT)) {
      DTF("task_in_intr to Soon wait for next interrupt\n");
      ide_set_handler(drive, &task_in_intr, WAIT_CMD, NULL);
      return ide_started;
    }
  }
  drive->io_32bit = 0;
  DTF("stat: %02x\n", stat);
#ifdef USEBIO
  if (rq->flags & REQ_CMD) {
    pBuf = ide_map_buffer(rq, &flags);
  } else {
    pBuf = rq->buffer + ((rq->nr_sectors - rq->current_nr_sectors) * SECTOR_SIZE);
  }
#else
  pBuf = rq->buffer + ((rq->nr_sectors - rq->current_nr_sectors) * SECTOR_SIZE);
#endif
  DTF("Read: %p, rq->current_nr_sectors: %d\n", pBuf, (int) rq->current_nr_sectors);
  taskfile_input_data(drive, pBuf, SECTOR_WORDS);
#ifdef USEBIO
  if (rq->flags & REQ_CMD)
    ide_unmap_buffer(pBuf, &flags);
  rq->sector++;
  rq->errors = 0;
#endif
  drive->io_32bit = io_32bit;
  if (--rq->current_nr_sectors <= 0) {
    /* (hs): swapped next 2 lines */
    DTF("Request Ended stat: %02x\n", GET_STAT());
    ide_end_request(1, HWGROUP(drive));
  } else {
    ide_set_handler(drive, &task_in_intr,  WAIT_CMD, NULL);
    return ide_started;
  }
  return ide_stopped;
}


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ksymoops 2.3.5 on i686 2.5.2-pre11.  Options used
     -V (default)
     -k /proc/ksyms (default)
     -l /proc/modules (default)
     -o /lib/modules/2.5.2-pre11/ (default)
     -m /usr/src/linux/System.map (specified)

No modules in ksyms, skipping objects
Warning (read_lsmod): no symbols in lsmod, is /proc/modules a valid lsmod file?
cpu: 0, clocks: 2659849, slice: 886616
cpu: 1, clocks: 2659849, slice: 886616
invalid operand: 0000
CPU:    0
EIP:    0010:[<c0136dd9>]    Not tainted
Using defaults from ksymoops -t elf32-i386 -a i386
EFLAGS: 00010283
eax: 00038000   ebx: 00000070   ecx: f70e4980   edx: f70e4980
esi: c0402084   edi: 00038000   ebp: f70e4980   esp: f6a01df4
ds: 0018   es: 0018   ss: 0018
Process hdparm (pid: 822, stackpage=f6a01000)
Stack: 00000000 c0402084 00000002 f70e4980 00001000 00000001 00000000 00000217 
       00000000 00000000 00000000 00000000 c01fcafe 00038000 00000070 f6a01e68 
       00000000 f7d10640 c0402084 f70e4980 00000002 00000000 00000000 00000002 
Call Trace: [<c01fcafe>] [<c01fd036>] [<c01fd14c>] [<c01fd1f9>] [<c013be3b>] 
   [<c013f00f>] [<c013ef70>] [<c012b7ce>] [<c012bc82>] [<c012bb90>] [<c01390ce>] 
   [<c0108c7f>] 
Code: 0f 0b c7 44 24 24 70 00 00 00 8b 1d 68 08 3e c0 89 5c 24 20 

>>EIP; c0136dd9 <create_bounce+49/2c0>   <=====
Trace; c01fcafe <__make_request+5e/470>
Trace; c01fd036 <generic_make_request+126/1b0>
Trace; c01fd14c <submit_bio+4c/60>
Trace; c01fd1f9 <submit_bh+99/a0>
Trace; c013be3b <block_read_full_page+1db/1f0>
Trace; c013f00f <blkdev_readpage+f/20>
Trace; c013ef70 <blkdev_get_block+0/40>
Trace; c012b7ce <do_generic_file_read+2de/460>
Trace; c012bc82 <generic_file_read+92/190>
Trace; c012bb90 <file_read_actor+0/60>
Trace; c01390ce <sys_read+8e/d0>
Trace; c0108c7f <system_call+33/38>
Code;  c0136dd9 <create_bounce+49/2c0>
00000000 <_EIP>:
Code;  c0136dd9 <create_bounce+49/2c0>   <=====
   0:   0f 0b                     ud2a      <=====
Code;  c0136ddb <create_bounce+4b/2c0>
   2:   c7 44 24 24 70 00 00      movl   $0x70,0x24(%esp,1)
Code;  c0136de2 <create_bounce+52/2c0>
   9:   00 
Code;  c0136de3 <create_bounce+53/2c0>
   a:   8b 1d 68 08 3e c0         mov    0xc03e0868,%ebx
Code;  c0136de9 <create_bounce+59/2c0>
  10:   89 5c 24 20               mov    %ebx,0x20(%esp,1)


1 warning issued.  Results may not be reliable.