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authorFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>2008-09-02 11:20:20 +0400
committerJens Axboe <jens.axboe@oracle.com>2008-10-09 10:56:12 +0400
commitfad7f01e61bf737fe8a3740d803f000db57ecac6 (patch)
treed72959e6b5043bf3436f122ebcddb0c8f41d1acf /drivers/scsi/sg.c
parent818827669d85b84241696ffef2de485db46b0b5e (diff)
downloadlinux-fad7f01e61bf737fe8a3740d803f000db57ecac6.tar.xz
sg: set dxferp to NULL for READ with the older SG interface
With the older SG interface, we don't know a user-space address to trasfer data when executing a SCSI command. So we can't pass a user-space address to blk_rq_map_user. This patch fixes sg to pass a NULL user-space address to blk_rq_map_user so that it just sets up a request and bios with page frames propely without data transfer. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'drivers/scsi/sg.c')
-rw-r--r--drivers/scsi/sg.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index ed69292babde..50c07bca727d 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -615,7 +615,10 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
else
hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
hp->dxfer_len = mxsize;
- hp->dxferp = (char __user *)buf + cmd_size;
+ if (hp->dxfer_direction == SG_DXFER_TO_DEV)
+ hp->dxferp = (char __user *)buf + cmd_size;
+ else
+ hp->dxferp = NULL;
hp->sbp = NULL;
hp->timeout = old_hdr.reply_len; /* structure abuse ... */
hp->flags = input_size; /* structure abuse ... */