ide-disk: fix flush requests (take 2)
commit 813a0eb233ee67d7166241a8b389b6a76f2247f9
Author: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Date: Fri Jan 25 22:17:10 2008 +0100
ide: switch idedisk_prepare_flush() to use REQ_TYPE_ATA_TASKFILE requests
...
broke flush requests.
Allocating IDE command structure on the stack for flush requests is not
a very brilliant idea:
- idedisk_prepare_flush() only prepares the request and it doesn't wait
for it to be completed
- there are can be multiple flush requests queued in the queue
Fix the problem (per hints from James Bottomley) by:
- dynamically allocating ide_task_t instance using kmalloc(..., GFP_ATOMIC)
- adding new taskfile flag (IDE_TFLAG_DYN)
- calling kfree() in ide_end_drive_command() if IDE_TFLAG_DYN is set
(while at it rename 'args' to 'task' and fix whitespace damage)
[ This will be fixed properly before 2.6.25 but this bug is rather
critical and the proper solution requires some more work + testing. ]
Thanks to Sebastian Siewior and Christoph Hellwig for reporting the
problem and testing patches (extra thanks to Sebastian for bisecting
it to the guilty commmit).
Tested-by: Sebastian Siewior <ide-bug@ml.breakpoint.cc>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index e41383f..7153796 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -361,17 +361,21 @@
spin_unlock_irqrestore(&ide_lock, flags);
if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
- ide_task_t *args = (ide_task_t *) rq->special;
+ ide_task_t *task = (ide_task_t *)rq->special;
+
if (rq->errors == 0)
- rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
-
- if (args) {
- struct ide_taskfile *tf = &args->tf;
+ rq->errors = !OK_STAT(stat, READY_STAT, BAD_STAT);
+
+ if (task) {
+ struct ide_taskfile *tf = &task->tf;
tf->error = err;
tf->status = stat;
- ide_tf_read(drive, args);
+ ide_tf_read(drive, task);
+
+ if (task->tf_flags & IDE_TFLAG_DYN)
+ kfree(task);
}
} else if (blk_pm_request(rq)) {
struct request_pm_state *pm = rq->data;