diff options
Diffstat (limited to 'patches/libata-alignment-2.6.37.patch')
| -rw-r--r-- | patches/libata-alignment-2.6.37.patch | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/patches/libata-alignment-2.6.37.patch b/patches/libata-alignment-2.6.37.patch new file mode 100644 index 0000000..1c26528 --- /dev/null +++ b/patches/libata-alignment-2.6.37.patch @@ -0,0 +1,71 @@ +ata_pio_sectors() expects buffer for each sector to be contained in a +single page; otherwise, it ends up overrunning the first page. This +is achieved by setting queue DMA alignment. If sector_size is smaller +than PAGE_SIZE and all buffers are sector_size aligned, buffer for +each sector is always contained in a single page. + +This wasn't applied to ATAPI devices but IDENTIFY_PACKET is executed +as ATA_PROT_PIO and thus uses ata_pio_sectors(). Newer versions of +udev issue IDENTIFY_PACKET with unaligned buffer triggering the +problem and causing oops. + +This patch fixes the problem by setting sdev->sector_size to +ATA_SECT_SIZE on ATATPI devices and always setting DMA alignment to +sector_size. While at it, add a warning for the unlikely but still +possible scenario where sector_size is larger than PAGE_SIZE, in which +case the alignment wouldn't be enough. + +Signed-off-by: Tejun Heo <tj@kernel.org> +Reported-by: John Stanley <jpsinthemix@verizon.net> +Tested-by: John Stanley <jpsinthemix@verizon.net> +Cc: stable@kernel.org +--- + drivers/ata/libata-scsi.c | 24 ++++++++++++++++++------ + 1 file changed, 18 insertions(+), 6 deletions(-) + +diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c +index 5defc74..600f635 100644 +--- a/drivers/ata/libata-scsi.c ++++ b/drivers/ata/libata-scsi.c +@@ -1099,9 +1099,9 @@ static int ata_scsi_dev_config(struct scsi_device *sdev, + struct request_queue *q = sdev->request_queue; + void *buf; + +- /* set the min alignment and padding */ +- blk_queue_update_dma_alignment(sdev->request_queue, +- ATA_DMA_PAD_SZ - 1); ++ sdev->sector_size = ATA_SECT_SIZE; ++ ++ /* set DMA padding */ + blk_queue_update_dma_pad(sdev->request_queue, + ATA_DMA_PAD_SZ - 1); + +@@ -1115,13 +1115,25 @@ static int ata_scsi_dev_config(struct scsi_device *sdev, + + blk_queue_dma_drain(q, atapi_drain_needed, buf, ATAPI_MAX_DRAIN); + } else { +- /* ATA devices must be sector aligned */ + sdev->sector_size = ata_id_logical_sector_size(dev->id); +- blk_queue_update_dma_alignment(sdev->request_queue, +- sdev->sector_size - 1); + sdev->manage_start_stop = 1; + } + ++ /* ++ * ata_pio_sectors() expects buffer for each sector to not cross ++ * page boundary. Enforce it by requiring buffers to be sector ++ * aligned, which works iff sector_size is not larger than ++ * PAGE_SIZE. ATAPI devices also need the alignment as ++ * IDENTIFY_PACKET is executed as ATA_PROT_PIO. ++ */ ++ if (sdev->sector_size > PAGE_SIZE) ++ ata_dev_printk(dev, KERN_WARNING, ++ "sector_size=%u > PAGE_SIZE, PIO may malfunction\n", ++ sdev->sector_size); ++ ++ blk_queue_update_dma_alignment(sdev->request_queue, ++ sdev->sector_size - 1); ++ + if (dev->flags & ATA_DFLAG_AN) + set_bit(SDEV_EVT_MEDIA_CHANGE, sdev->supported_events); + |