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>
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 7d41afe..563ef0b 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -2678,6 +2678,18 @@
tf->device = qc->dev->devno ?
tf->device | ATA_DEV1 : tf->device & ~ATA_DEV1;
+ /* READ/WRITE LONG use a non-standard sect_size */
+ qc->sect_size = ATA_SECT_SIZE;
+ switch (tf->command) {
+ case ATA_CMD_READ_LONG:
+ case ATA_CMD_READ_LONG_ONCE:
+ case ATA_CMD_WRITE_LONG:
+ case ATA_CMD_WRITE_LONG_ONCE:
+ if (tf->protocol != ATA_PROT_PIO || tf->nsect != 1)
+ goto invalid_fld;
+ qc->sect_size = scmd->request_bufflen;
+ }
+
/*
* Filter SET_FEATURES - XFER MODE command -- otherwise,
* SET_FEATURES - XFER MODE must be preceded/succeeded