libata: add support for READ/WRITE LONG

The READ/WRITE LONG commands are theoretically obsolete,
but the majority of drives in existance still implement them.

The WRITE_LONG and WRITE_LONG_ONCE commands are of particular
interest for fault injection testing -- eg. creating "media errors"
at specific locations on a disk.

The fussy bit is that these commands require a non-standard
sector size, usually 520 bytes instead of 512.

This patch adds support to libata for READ/WRITE LONG commands
issued via SG_IO/ATA_16.

Signed-off-by:  Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 5a40a8d95114..12237d4b9f9b 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -427,6 +427,7 @@ struct ata_queued_cmd {
         int                     dma_dir;
 
         unsigned int            pad_len;
+        unsigned int            sect_size;
 
         unsigned int            nbytes;
         unsigned int            curbytes;
@@ -1182,6 +1183,7 @@ static inline void ata_qc_reinit(struct ata_queued_cmd *qc)
         qc->n_elem = 0;
         qc->err_mask = 0;
         qc->pad_len = 0;
+        qc->sect_size = ATA_SECT_SIZE;
 
         ata_tf_init(qc->dev, &qc->tf);