linux/drivers/ide/ide-park.c
Jens Axboe 9a6d548800 ide: ensure atapi sense request aren't preempted
There's an issue with how sense requests are handled in IDE. If ide-cd
encounters an error, it queues a sense request. With how IDE request
handling is done, this is the next request we need to handle. But it's
impossible to guarantee this, as another request could come in between
the sense being queued, and ->queue_rq() being run and handling it. If
that request ALSO fails, then we attempt to doubly queue the single
sense request we have.

Since we only support one active request at the time, defer request
processing when a sense request is queued.

Fixes: 600335205b "ide: convert to blk-mq"
Reported-by: He Zhe <zhe.he@windriver.com>
Tested-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-01-31 08:25:09 -07:00

156 lines
3.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/ide.h>
#include <linux/jiffies.h>
#include <linux/blkdev.h>
DECLARE_WAIT_QUEUE_HEAD(ide_park_wq);
static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout)
{
ide_hwif_t *hwif = drive->hwif;
struct request_queue *q = drive->queue;
struct request *rq;
int rc;
timeout += jiffies;
spin_lock_irq(&hwif->lock);
if (drive->dev_flags & IDE_DFLAG_PARKED) {
int reset_timer = time_before(timeout, drive->sleep);
int start_queue = 0;
drive->sleep = timeout;
wake_up_all(&ide_park_wq);
if (reset_timer && del_timer(&hwif->timer))
start_queue = 1;
spin_unlock_irq(&hwif->lock);
if (start_queue)
blk_mq_run_hw_queues(q, true);
return;
}
spin_unlock_irq(&hwif->lock);
rq = blk_get_request(q, REQ_OP_DRV_IN, 0);
scsi_req(rq)->cmd[0] = REQ_PARK_HEADS;
scsi_req(rq)->cmd_len = 1;
ide_req(rq)->type = ATA_PRIV_MISC;
ide_req(rq)->special = &timeout;
blk_execute_rq(q, NULL, rq, 1);
rc = scsi_req(rq)->result ? -EIO : 0;
blk_put_request(rq);
if (rc)
goto out;
/*
* Make sure that *some* command is sent to the drive after the
* timeout has expired, so power management will be reenabled.
*/
rq = blk_get_request(q, REQ_OP_DRV_IN, BLK_MQ_REQ_NOWAIT);
if (IS_ERR(rq))
goto out;
scsi_req(rq)->cmd[0] = REQ_UNPARK_HEADS;
scsi_req(rq)->cmd_len = 1;
ide_req(rq)->type = ATA_PRIV_MISC;
spin_lock_irq(&hwif->lock);
ide_insert_request_head(drive, rq);
spin_unlock_irq(&hwif->lock);
out:
return;
}
ide_startstop_t ide_do_park_unpark(ide_drive_t *drive, struct request *rq)
{
struct ide_cmd cmd;
struct ide_taskfile *tf = &cmd.tf;
memset(&cmd, 0, sizeof(cmd));
if (scsi_req(rq)->cmd[0] == REQ_PARK_HEADS) {
drive->sleep = *(unsigned long *)ide_req(rq)->special;
drive->dev_flags |= IDE_DFLAG_SLEEPING;
tf->command = ATA_CMD_IDLEIMMEDIATE;
tf->feature = 0x44;
tf->lbal = 0x4c;
tf->lbam = 0x4e;
tf->lbah = 0x55;
cmd.valid.out.tf = IDE_VALID_OUT_TF | IDE_VALID_DEVICE;
cmd.valid.in.tf = IDE_VALID_IN_TF | IDE_VALID_DEVICE;
} else /* cmd == REQ_UNPARK_HEADS */
tf->command = ATA_CMD_CHK_POWER;
cmd.tf_flags |= IDE_TFLAG_CUSTOM_HANDLER;
cmd.protocol = ATA_PROT_NODATA;
cmd.rq = rq;
return do_rw_taskfile(drive, &cmd);
}
ssize_t ide_park_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
ide_drive_t *drive = to_ide_device(dev);
ide_hwif_t *hwif = drive->hwif;
unsigned long now;
unsigned int msecs;
if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)
return -EOPNOTSUPP;
spin_lock_irq(&hwif->lock);
now = jiffies;
if (drive->dev_flags & IDE_DFLAG_PARKED &&
time_after(drive->sleep, now))
msecs = jiffies_to_msecs(drive->sleep - now);
else
msecs = 0;
spin_unlock_irq(&hwif->lock);
return snprintf(buf, 20, "%u\n", msecs);
}
ssize_t ide_park_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t len)
{
#define MAX_PARK_TIMEOUT 30000
ide_drive_t *drive = to_ide_device(dev);
long int input;
int rc;
rc = kstrtol(buf, 10, &input);
if (rc)
return rc;
if (input < -2)
return -EINVAL;
if (input > MAX_PARK_TIMEOUT) {
input = MAX_PARK_TIMEOUT;
rc = -EOVERFLOW;
}
mutex_lock(&ide_setting_mtx);
if (input >= 0) {
if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)
rc = -EOPNOTSUPP;
else if (input || drive->dev_flags & IDE_DFLAG_PARKED)
issue_park_cmd(drive, msecs_to_jiffies(input));
} else {
if (drive->media == ide_disk)
switch (input) {
case -1:
drive->dev_flags &= ~IDE_DFLAG_NO_UNLOAD;
break;
case -2:
drive->dev_flags |= IDE_DFLAG_NO_UNLOAD;
break;
}
else
rc = -EOPNOTSUPP;
}
mutex_unlock(&ide_setting_mtx);
return rc ? rc : len;
}