Hi
This fixes a crash when using hdparm --security-* on IDE devices with CFQ
scheduler.
BTW. I found out that it's impossible to use these security commands on
sparc64 because of 64-bit kernel, 32-bit userspace and a lack of ioctl
emulation (I succeeded when I recompiled hdparm on my own in 64-bit mode).
What do you think is the best fix for it? Put it to fs/compat_ioctl.c
(like SG_IO)? Or make a compat_ioctl method in IDE? Or don't fix it and
persuade distros to compile hdparm as 64-bit?
Mikulas
---
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@xxxxxxxxxx>
---
drivers/ide/ide-taskfile.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
Index: linux-2.6.34-rc2-fast/drivers/ide/ide-taskfile.c
===================================================================
--- linux-2.6.34-rc2-fast.orig/drivers/ide/ide-taskfile.c 2010-03-29 21:44:59.000000000 +0200
+++ linux-2.6.34-rc2-fast/drivers/ide/ide-taskfile.c 2010-03-29 21:52:04.000000000 +0200
@@ -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,
--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
