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ide: Fix IDE taskfile with cfq scheduler 

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>
This commit is contained in:
Mikulas Patocka 2010-04-06 16:43:33 -07:00 committed by David S. Miller
parent 1af1850346
commit 720fc22a7a
1 changed files with 2 additions and 4 deletions
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6
drivers/ide/ide-taskfile.c
View File

@ -428,13 +428,11 @@ int ide_raw_taskfile(ide_drive_t *drive, struct ide_cmd *cmd, u8 *buf,
{
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,