| From 720fc22a7af79d91ec460c80efa92c65c12d105e Mon Sep 17 00:00:00 2001 |
| From: Mikulas Patocka <mpatocka@redhat.com> |
| Date: Tue, 6 Apr 2010 16:43:33 -0700 |
| Subject: ide: Fix IDE taskfile with cfq scheduler |
| |
| From: Mikulas Patocka <mpatocka@redhat.com> |
| |
| commit 720fc22a7af79d91ec460c80efa92c65c12d105e upstream. |
| |
| When ide taskfile access is being used (for example with hdparm --security |
| commands) and cfq scheduler is selected, the scheduler crashes on BUG in |
| cfq_put_request. |
| |
| The reason is that the cfq scheduler is tracking counts of read and write |
| requests separately; the ide-taskfile subsystem allocates a read request and |
| then flips the flag to make it a write request. The counters in cfq will |
| mismatch. |
| |
| This patch changes ide-taskfile to allocate the READ or WRITE request as |
| required and don't change the flag later. |
| |
| Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| drivers/ide/ide-taskfile.c | 6 ++---- |
| 1 file changed, 2 insertions(+), 4 deletions(-) |
| |
| --- a/drivers/ide/ide-taskfile.c |
| +++ b/drivers/ide/ide-taskfile.c |
| @@ -428,13 +428,11 @@ int ide_raw_taskfile(ide_drive_t *drive, |
| { |
| struct request *rq; |
| int error; |
| + int rw = !(cmd->tf_flags & IDE_TFLAG_WRITE) ? READ : WRITE; |
| |
| - rq = blk_get_request(drive->queue, READ, __GFP_WAIT); |
| + rq = blk_get_request(drive->queue, rw, __GFP_WAIT); |
| rq->cmd_type = REQ_TYPE_ATA_TASKFILE; |
| |
| - if (cmd->tf_flags & IDE_TFLAG_WRITE) |
| - rq->cmd_flags |= REQ_RW; |
| - |
| /* |
| * (ks) We transfer currently only whole sectors. |
| * This is suffient for now. But, it would be great, |
