kernel26-vserver-grsec/libata-alignment.patch

   1 diff -Nur linux-2.6.32.orig/drivers/ata/libata-scsi.c linux-2.6.32/drivers/ata/libata-scsi.c
   2 --- linux-2.6.32.orig/drivers/ata/libata-scsi.c 2009-12-03 14:51:21.000000000 +1100
   3 +++ linux-2.6.32/drivers/ata/libata-scsi.c      2011-01-22 20:32:53.353775375 +1100
   4 @@ -1099,13 +1099,13 @@
   5         /* configure max sectors */
   6         blk_queue_max_sectors(sdev->request_queue, dev->max_sectors);
   7
   8 +       sdev->sector_size = ATA_SECT_SIZE;
   9 +
  10         if (dev->class == ATA_DEV_ATAPI) {
  11                 struct request_queue *q = sdev->request_queue;
  12                 void *buf;
  13
  14 -               /* set the min alignment and padding */
  15 -               blk_queue_update_dma_alignment(sdev->request_queue,
  16 -                                              ATA_DMA_PAD_SZ - 1);
  17 +               /* set DMA padding */
  18                 blk_queue_update_dma_pad(sdev->request_queue,
  19                                          ATA_DMA_PAD_SZ - 1);
  20
  21 @@ -1119,12 +1119,24 @@
  22
  23                 blk_queue_dma_drain(q, atapi_drain_needed, buf, ATAPI_MAX_DRAIN);
  24         } else {
  25 -               /* ATA devices must be sector aligned */
  26 -               blk_queue_update_dma_alignment(sdev->request_queue,
  27 -                                              ATA_SECT_SIZE - 1);
  28                 sdev->manage_start_stop = 1;
  29         }
  30
  31 +       /*
  32 +        * ata_pio_sectors() expects buffer for each sector to not cross
  33 +        * page boundary.  Enforce it by requiring buffers to be sector
  34 +        * aligned, which works iff sector_size is not larger than
  35 +        * PAGE_SIZE.  ATAPI devices also need the alignment as
  36 +        * IDENTIFY_PACKET is executed as ATA_PROT_PIO.
  37 +        */
  38 +       if (sdev->sector_size > PAGE_SIZE)
  39 +               ata_dev_printk(dev, KERN_WARNING,
  40 +                       "sector_size=%u > PAGE_SIZE, PIO may malfunction\n",
  41 +                       sdev->sector_size);
  42 +
  43 +       blk_queue_update_dma_alignment(sdev->request_queue,
  44 +                                      sdev->sector_size - 1);
  45 +
  46         if (dev->flags & ATA_DFLAG_AN)
  47                 set_bit(SDEV_EVT_MEDIA_CHANGE, sdev->supported_events);
  48