linux/drivers/ide/ide-park.c

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ide: Implement disk shock protection support (v4) On user request (through sysfs), the IDLE IMMEDIATE command with UNLOAD FEATURE as specified in ATA-7 is issued to the device and processing of the request queue is stopped thereafter until the specified timeout expires or user space asks to resume normal operation. This is supposed to prevent the heads of a hard drive from accidentally crashing onto the platter when a heavy shock is anticipated (like a falling laptop expected to hit the floor). Port resets are deferred whenever a device on that port is in the parked state. v3: Elias Oltmanns <eo@nebensachen.de> wrote: [...] > >> 1. Make sure that no negative value is being passed to > >> jiffies_to_msecs() in ide_park_show(). > >> 2. Drop the superfluous variable hwif in ide_special_rq(). > >> 3. Skip initialisation of task and tf in ide_special_rq() if we are not > >> handling a (un)park request. > > > > Well, #3 should have been done differently because we donn't want to > > check for REQ_(UN)?PARK_HEADS more often than is necessary. > > While preparing the backport to 2.6.27, it has just occurred to me that > we need to clear the IDE_DFLAG_PARKED flag in ide_disk_pre_reset() > because this flag must not be set after *any* sort of access to the > device. v4: Fix a memory leak due to a missing blk_put_request() in issue_park_cmd(). Additionally, we should plug the queue when enqueueing the unpark request because there is no guarantee that the park timeout has not expired by then. Even though the chance for that to happen is very slim, the request might end up hanging in the queue until the next I/O operation is queued up. While at it, clean up the code a little: - make issue_park_cmd() a function of type void since nobody cares for the return value anyway; - use blk_start_queueing() instead of __blk_run_queue() since we don't have to worry about recursion; - remove a superfluous pointer deference in task_no_data_intr(). Signed-off-by: Elias Oltmanns <eo@nebensachen.de> Cc: Jeff Garzik <jeff@garzik.org>, Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Tejun Heo <htejun@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2008-10-13 19:39:50 +00:00
#include <linux/kernel.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/gfp.h>
ide: Implement disk shock protection support (v4) On user request (through sysfs), the IDLE IMMEDIATE command with UNLOAD FEATURE as specified in ATA-7 is issued to the device and processing of the request queue is stopped thereafter until the specified timeout expires or user space asks to resume normal operation. This is supposed to prevent the heads of a hard drive from accidentally crashing onto the platter when a heavy shock is anticipated (like a falling laptop expected to hit the floor). Port resets are deferred whenever a device on that port is in the parked state. v3: Elias Oltmanns <eo@nebensachen.de> wrote: [...] > >> 1. Make sure that no negative value is being passed to > >> jiffies_to_msecs() in ide_park_show(). > >> 2. Drop the superfluous variable hwif in ide_special_rq(). > >> 3. Skip initialisation of task and tf in ide_special_rq() if we are not > >> handling a (un)park request. > > > > Well, #3 should have been done differently because we donn't want to > > check for REQ_(UN)?PARK_HEADS more often than is necessary. > > While preparing the backport to 2.6.27, it has just occurred to me that > we need to clear the IDE_DFLAG_PARKED flag in ide_disk_pre_reset() > because this flag must not be set after *any* sort of access to the > device. v4: Fix a memory leak due to a missing blk_put_request() in issue_park_cmd(). Additionally, we should plug the queue when enqueueing the unpark request because there is no guarantee that the park timeout has not expired by then. Even though the chance for that to happen is very slim, the request might end up hanging in the queue until the next I/O operation is queued up. While at it, clean up the code a little: - make issue_park_cmd() a function of type void since nobody cares for the return value anyway; - use blk_start_queueing() instead of __blk_run_queue() since we don't have to worry about recursion; - remove a superfluous pointer deference in task_no_data_intr(). Signed-off-by: Elias Oltmanns <eo@nebensachen.de> Cc: Jeff Garzik <jeff@garzik.org>, Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Tejun Heo <htejun@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2008-10-13 19:39:50 +00:00
#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;
ide: Implement disk shock protection support (v4) On user request (through sysfs), the IDLE IMMEDIATE command with UNLOAD FEATURE as specified in ATA-7 is issued to the device and processing of the request queue is stopped thereafter until the specified timeout expires or user space asks to resume normal operation. This is supposed to prevent the heads of a hard drive from accidentally crashing onto the platter when a heavy shock is anticipated (like a falling laptop expected to hit the floor). Port resets are deferred whenever a device on that port is in the parked state. v3: Elias Oltmanns <eo@nebensachen.de> wrote: [...] > >> 1. Make sure that no negative value is being passed to > >> jiffies_to_msecs() in ide_park_show(). > >> 2. Drop the superfluous variable hwif in ide_special_rq(). > >> 3. Skip initialisation of task and tf in ide_special_rq() if we are not > >> handling a (un)park request. > > > > Well, #3 should have been done differently because we donn't want to > > check for REQ_(UN)?PARK_HEADS more often than is necessary. > > While preparing the backport to 2.6.27, it has just occurred to me that > we need to clear the IDE_DFLAG_PARKED flag in ide_disk_pre_reset() > because this flag must not be set after *any* sort of access to the > device. v4: Fix a memory leak due to a missing blk_put_request() in issue_park_cmd(). Additionally, we should plug the queue when enqueueing the unpark request because there is no guarantee that the park timeout has not expired by then. Even though the chance for that to happen is very slim, the request might end up hanging in the queue until the next I/O operation is queued up. While at it, clean up the code a little: - make issue_park_cmd() a function of type void since nobody cares for the return value anyway; - use blk_start_queueing() instead of __blk_run_queue() since we don't have to worry about recursion; - remove a superfluous pointer deference in task_no_data_intr(). Signed-off-by: Elias Oltmanns <eo@nebensachen.de> Cc: Jeff Garzik <jeff@garzik.org>, Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Tejun Heo <htejun@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2008-10-13 19:39:50 +00:00
struct request_queue *q = drive->queue;
struct request *rq;
int rc;
timeout += jiffies;
spin_lock_irq(&hwif->lock);
ide: Implement disk shock protection support (v4) On user request (through sysfs), the IDLE IMMEDIATE command with UNLOAD FEATURE as specified in ATA-7 is issued to the device and processing of the request queue is stopped thereafter until the specified timeout expires or user space asks to resume normal operation. This is supposed to prevent the heads of a hard drive from accidentally crashing onto the platter when a heavy shock is anticipated (like a falling laptop expected to hit the floor). Port resets are deferred whenever a device on that port is in the parked state. v3: Elias Oltmanns <eo@nebensachen.de> wrote: [...] > >> 1. Make sure that no negative value is being passed to > >> jiffies_to_msecs() in ide_park_show(). > >> 2. Drop the superfluous variable hwif in ide_special_rq(). > >> 3. Skip initialisation of task and tf in ide_special_rq() if we are not > >> handling a (un)park request. > > > > Well, #3 should have been done differently because we donn't want to > > check for REQ_(UN)?PARK_HEADS more often than is necessary. > > While preparing the backport to 2.6.27, it has just occurred to me that > we need to clear the IDE_DFLAG_PARKED flag in ide_disk_pre_reset() > because this flag must not be set after *any* sort of access to the > device. v4: Fix a memory leak due to a missing blk_put_request() in issue_park_cmd(). Additionally, we should plug the queue when enqueueing the unpark request because there is no guarantee that the park timeout has not expired by then. Even though the chance for that to happen is very slim, the request might end up hanging in the queue until the next I/O operation is queued up. While at it, clean up the code a little: - make issue_park_cmd() a function of type void since nobody cares for the return value anyway; - use blk_start_queueing() instead of __blk_run_queue() since we don't have to worry about recursion; - remove a superfluous pointer deference in task_no_data_intr(). Signed-off-by: Elias Oltmanns <eo@nebensachen.de> Cc: Jeff Garzik <jeff@garzik.org>, Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Tejun Heo <htejun@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2008-10-13 19:39:50 +00:00
if (drive->dev_flags & IDE_DFLAG_PARKED) {
int reset_timer = time_before(timeout, drive->sleep);
int start_queue = 0;
ide: Implement disk shock protection support (v4) On user request (through sysfs), the IDLE IMMEDIATE command with UNLOAD FEATURE as specified in ATA-7 is issued to the device and processing of the request queue is stopped thereafter until the specified timeout expires or user space asks to resume normal operation. This is supposed to prevent the heads of a hard drive from accidentally crashing onto the platter when a heavy shock is anticipated (like a falling laptop expected to hit the floor). Port resets are deferred whenever a device on that port is in the parked state. v3: Elias Oltmanns <eo@nebensachen.de> wrote: [...] > >> 1. Make sure that no negative value is being passed to > >> jiffies_to_msecs() in ide_park_show(). > >> 2. Drop the superfluous variable hwif in ide_special_rq(). > >> 3. Skip initialisation of task and tf in ide_special_rq() if we are not > >> handling a (un)park request. > > > > Well, #3 should have been done differently because we donn't want to > > check for REQ_(UN)?PARK_HEADS more often than is necessary. > > While preparing the backport to 2.6.27, it has just occurred to me that > we need to clear the IDE_DFLAG_PARKED flag in ide_disk_pre_reset() > because this flag must not be set after *any* sort of access to the > device. v4: Fix a memory leak due to a missing blk_put_request() in issue_park_cmd(). Additionally, we should plug the queue when enqueueing the unpark request because there is no guarantee that the park timeout has not expired by then. Even though the chance for that to happen is very slim, the request might end up hanging in the queue until the next I/O operation is queued up. While at it, clean up the code a little: - make issue_park_cmd() a function of type void since nobody cares for the return value anyway; - use blk_start_queueing() instead of __blk_run_queue() since we don't have to worry about recursion; - remove a superfluous pointer deference in task_no_data_intr(). Signed-off-by: Elias Oltmanns <eo@nebensachen.de> Cc: Jeff Garzik <jeff@garzik.org>, Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Tejun Heo <htejun@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2008-10-13 19:39:50 +00:00
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_run_queue(q);
ide: Implement disk shock protection support (v4) On user request (through sysfs), the IDLE IMMEDIATE command with UNLOAD FEATURE as specified in ATA-7 is issued to the device and processing of the request queue is stopped thereafter until the specified timeout expires or user space asks to resume normal operation. This is supposed to prevent the heads of a hard drive from accidentally crashing onto the platter when a heavy shock is anticipated (like a falling laptop expected to hit the floor). Port resets are deferred whenever a device on that port is in the parked state. v3: Elias Oltmanns <eo@nebensachen.de> wrote: [...] > >> 1. Make sure that no negative value is being passed to > >> jiffies_to_msecs() in ide_park_show(). > >> 2. Drop the superfluous variable hwif in ide_special_rq(). > >> 3. Skip initialisation of task and tf in ide_special_rq() if we are not > >> handling a (un)park request. > > > > Well, #3 should have been done differently because we donn't want to > > check for REQ_(UN)?PARK_HEADS more often than is necessary. > > While preparing the backport to 2.6.27, it has just occurred to me that > we need to clear the IDE_DFLAG_PARKED flag in ide_disk_pre_reset() > because this flag must not be set after *any* sort of access to the > device. v4: Fix a memory leak due to a missing blk_put_request() in issue_park_cmd(). Additionally, we should plug the queue when enqueueing the unpark request because there is no guarantee that the park timeout has not expired by then. Even though the chance for that to happen is very slim, the request might end up hanging in the queue until the next I/O operation is queued up. While at it, clean up the code a little: - make issue_park_cmd() a function of type void since nobody cares for the return value anyway; - use blk_start_queueing() instead of __blk_run_queue() since we don't have to worry about recursion; - remove a superfluous pointer deference in task_no_data_intr(). Signed-off-by: Elias Oltmanns <eo@nebensachen.de> Cc: Jeff Garzik <jeff@garzik.org>, Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Tejun Heo <htejun@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2008-10-13 19:39:50 +00:00
return;
}
spin_unlock_irq(&hwif->lock);
ide: Implement disk shock protection support (v4) On user request (through sysfs), the IDLE IMMEDIATE command with UNLOAD FEATURE as specified in ATA-7 is issued to the device and processing of the request queue is stopped thereafter until the specified timeout expires or user space asks to resume normal operation. This is supposed to prevent the heads of a hard drive from accidentally crashing onto the platter when a heavy shock is anticipated (like a falling laptop expected to hit the floor). Port resets are deferred whenever a device on that port is in the parked state. v3: Elias Oltmanns <eo@nebensachen.de> wrote: [...] > >> 1. Make sure that no negative value is being passed to > >> jiffies_to_msecs() in ide_park_show(). > >> 2. Drop the superfluous variable hwif in ide_special_rq(). > >> 3. Skip initialisation of task and tf in ide_special_rq() if we are not > >> handling a (un)park request. > > > > Well, #3 should have been done differently because we donn't want to > > check for REQ_(UN)?PARK_HEADS more often than is necessary. > > While preparing the backport to 2.6.27, it has just occurred to me that > we need to clear the IDE_DFLAG_PARKED flag in ide_disk_pre_reset() > because this flag must not be set after *any* sort of access to the > device. v4: Fix a memory leak due to a missing blk_put_request() in issue_park_cmd(). Additionally, we should plug the queue when enqueueing the unpark request because there is no guarantee that the park timeout has not expired by then. Even though the chance for that to happen is very slim, the request might end up hanging in the queue until the next I/O operation is queued up. While at it, clean up the code a little: - make issue_park_cmd() a function of type void since nobody cares for the return value anyway; - use blk_start_queueing() instead of __blk_run_queue() since we don't have to worry about recursion; - remove a superfluous pointer deference in task_no_data_intr(). Signed-off-by: Elias Oltmanns <eo@nebensachen.de> Cc: Jeff Garzik <jeff@garzik.org>, Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Tejun Heo <htejun@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2008-10-13 19:39:50 +00:00
rq = blk_get_request(q, READ, __GFP_WAIT);
rq->cmd[0] = REQ_PARK_HEADS;
rq->cmd_len = 1;
rq->cmd_type = REQ_TYPE_SPECIAL;
rq->special = &timeout;
rc = blk_execute_rq(q, NULL, rq, 1);
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, READ, GFP_NOWAIT);
if (unlikely(!rq))
goto out;
rq->cmd[0] = REQ_UNPARK_HEADS;
rq->cmd_len = 1;
rq->cmd_type = REQ_TYPE_SPECIAL;
elv_add_request(q, rq, ELEVATOR_INSERT_FRONT);
ide: Implement disk shock protection support (v4) On user request (through sysfs), the IDLE IMMEDIATE command with UNLOAD FEATURE as specified in ATA-7 is issued to the device and processing of the request queue is stopped thereafter until the specified timeout expires or user space asks to resume normal operation. This is supposed to prevent the heads of a hard drive from accidentally crashing onto the platter when a heavy shock is anticipated (like a falling laptop expected to hit the floor). Port resets are deferred whenever a device on that port is in the parked state. v3: Elias Oltmanns <eo@nebensachen.de> wrote: [...] > >> 1. Make sure that no negative value is being passed to > >> jiffies_to_msecs() in ide_park_show(). > >> 2. Drop the superfluous variable hwif in ide_special_rq(). > >> 3. Skip initialisation of task and tf in ide_special_rq() if we are not > >> handling a (un)park request. > > > > Well, #3 should have been done differently because we donn't want to > > check for REQ_(UN)?PARK_HEADS more often than is necessary. > > While preparing the backport to 2.6.27, it has just occurred to me that > we need to clear the IDE_DFLAG_PARKED flag in ide_disk_pre_reset() > because this flag must not be set after *any* sort of access to the > device. v4: Fix a memory leak due to a missing blk_put_request() in issue_park_cmd(). Additionally, we should plug the queue when enqueueing the unpark request because there is no guarantee that the park timeout has not expired by then. Even though the chance for that to happen is very slim, the request might end up hanging in the queue until the next I/O operation is queued up. While at it, clean up the code a little: - make issue_park_cmd() a function of type void since nobody cares for the return value anyway; - use blk_start_queueing() instead of __blk_run_queue() since we don't have to worry about recursion; - remove a superfluous pointer deference in task_no_data_intr(). Signed-off-by: Elias Oltmanns <eo@nebensachen.de> Cc: Jeff Garzik <jeff@garzik.org>, Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Tejun Heo <htejun@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2008-10-13 19:39:50 +00:00
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 (rq->cmd[0] == REQ_PARK_HEADS) {
drive->sleep = *(unsigned long *)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);
}
ide: Implement disk shock protection support (v4) On user request (through sysfs), the IDLE IMMEDIATE command with UNLOAD FEATURE as specified in ATA-7 is issued to the device and processing of the request queue is stopped thereafter until the specified timeout expires or user space asks to resume normal operation. This is supposed to prevent the heads of a hard drive from accidentally crashing onto the platter when a heavy shock is anticipated (like a falling laptop expected to hit the floor). Port resets are deferred whenever a device on that port is in the parked state. v3: Elias Oltmanns <eo@nebensachen.de> wrote: [...] > >> 1. Make sure that no negative value is being passed to > >> jiffies_to_msecs() in ide_park_show(). > >> 2. Drop the superfluous variable hwif in ide_special_rq(). > >> 3. Skip initialisation of task and tf in ide_special_rq() if we are not > >> handling a (un)park request. > > > > Well, #3 should have been done differently because we donn't want to > > check for REQ_(UN)?PARK_HEADS more often than is necessary. > > While preparing the backport to 2.6.27, it has just occurred to me that > we need to clear the IDE_DFLAG_PARKED flag in ide_disk_pre_reset() > because this flag must not be set after *any* sort of access to the > device. v4: Fix a memory leak due to a missing blk_put_request() in issue_park_cmd(). Additionally, we should plug the queue when enqueueing the unpark request because there is no guarantee that the park timeout has not expired by then. Even though the chance for that to happen is very slim, the request might end up hanging in the queue until the next I/O operation is queued up. While at it, clean up the code a little: - make issue_park_cmd() a function of type void since nobody cares for the return value anyway; - use blk_start_queueing() instead of __blk_run_queue() since we don't have to worry about recursion; - remove a superfluous pointer deference in task_no_data_intr(). Signed-off-by: Elias Oltmanns <eo@nebensachen.de> Cc: Jeff Garzik <jeff@garzik.org>, Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Tejun Heo <htejun@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2008-10-13 19:39:50 +00:00
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;
ide: Implement disk shock protection support (v4) On user request (through sysfs), the IDLE IMMEDIATE command with UNLOAD FEATURE as specified in ATA-7 is issued to the device and processing of the request queue is stopped thereafter until the specified timeout expires or user space asks to resume normal operation. This is supposed to prevent the heads of a hard drive from accidentally crashing onto the platter when a heavy shock is anticipated (like a falling laptop expected to hit the floor). Port resets are deferred whenever a device on that port is in the parked state. v3: Elias Oltmanns <eo@nebensachen.de> wrote: [...] > >> 1. Make sure that no negative value is being passed to > >> jiffies_to_msecs() in ide_park_show(). > >> 2. Drop the superfluous variable hwif in ide_special_rq(). > >> 3. Skip initialisation of task and tf in ide_special_rq() if we are not > >> handling a (un)park request. > > > > Well, #3 should have been done differently because we donn't want to > > check for REQ_(UN)?PARK_HEADS more often than is necessary. > > While preparing the backport to 2.6.27, it has just occurred to me that > we need to clear the IDE_DFLAG_PARKED flag in ide_disk_pre_reset() > because this flag must not be set after *any* sort of access to the > device. v4: Fix a memory leak due to a missing blk_put_request() in issue_park_cmd(). Additionally, we should plug the queue when enqueueing the unpark request because there is no guarantee that the park timeout has not expired by then. Even though the chance for that to happen is very slim, the request might end up hanging in the queue until the next I/O operation is queued up. While at it, clean up the code a little: - make issue_park_cmd() a function of type void since nobody cares for the return value anyway; - use blk_start_queueing() instead of __blk_run_queue() since we don't have to worry about recursion; - remove a superfluous pointer deference in task_no_data_intr(). Signed-off-by: Elias Oltmanns <eo@nebensachen.de> Cc: Jeff Garzik <jeff@garzik.org>, Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Tejun Heo <htejun@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2008-10-13 19:39:50 +00:00
unsigned long now;
unsigned int msecs;
if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)
return -EOPNOTSUPP;
spin_lock_irq(&hwif->lock);
ide: Implement disk shock protection support (v4) On user request (through sysfs), the IDLE IMMEDIATE command with UNLOAD FEATURE as specified in ATA-7 is issued to the device and processing of the request queue is stopped thereafter until the specified timeout expires or user space asks to resume normal operation. This is supposed to prevent the heads of a hard drive from accidentally crashing onto the platter when a heavy shock is anticipated (like a falling laptop expected to hit the floor). Port resets are deferred whenever a device on that port is in the parked state. v3: Elias Oltmanns <eo@nebensachen.de> wrote: [...] > >> 1. Make sure that no negative value is being passed to > >> jiffies_to_msecs() in ide_park_show(). > >> 2. Drop the superfluous variable hwif in ide_special_rq(). > >> 3. Skip initialisation of task and tf in ide_special_rq() if we are not > >> handling a (un)park request. > > > > Well, #3 should have been done differently because we donn't want to > > check for REQ_(UN)?PARK_HEADS more often than is necessary. > > While preparing the backport to 2.6.27, it has just occurred to me that > we need to clear the IDE_DFLAG_PARKED flag in ide_disk_pre_reset() > because this flag must not be set after *any* sort of access to the > device. v4: Fix a memory leak due to a missing blk_put_request() in issue_park_cmd(). Additionally, we should plug the queue when enqueueing the unpark request because there is no guarantee that the park timeout has not expired by then. Even though the chance for that to happen is very slim, the request might end up hanging in the queue until the next I/O operation is queued up. While at it, clean up the code a little: - make issue_park_cmd() a function of type void since nobody cares for the return value anyway; - use blk_start_queueing() instead of __blk_run_queue() since we don't have to worry about recursion; - remove a superfluous pointer deference in task_no_data_intr(). Signed-off-by: Elias Oltmanns <eo@nebensachen.de> Cc: Jeff Garzik <jeff@garzik.org>, Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Tejun Heo <htejun@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2008-10-13 19:39:50 +00:00
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);
ide: Implement disk shock protection support (v4) On user request (through sysfs), the IDLE IMMEDIATE command with UNLOAD FEATURE as specified in ATA-7 is issued to the device and processing of the request queue is stopped thereafter until the specified timeout expires or user space asks to resume normal operation. This is supposed to prevent the heads of a hard drive from accidentally crashing onto the platter when a heavy shock is anticipated (like a falling laptop expected to hit the floor). Port resets are deferred whenever a device on that port is in the parked state. v3: Elias Oltmanns <eo@nebensachen.de> wrote: [...] > >> 1. Make sure that no negative value is being passed to > >> jiffies_to_msecs() in ide_park_show(). > >> 2. Drop the superfluous variable hwif in ide_special_rq(). > >> 3. Skip initialisation of task and tf in ide_special_rq() if we are not > >> handling a (un)park request. > > > > Well, #3 should have been done differently because we donn't want to > > check for REQ_(UN)?PARK_HEADS more often than is necessary. > > While preparing the backport to 2.6.27, it has just occurred to me that > we need to clear the IDE_DFLAG_PARKED flag in ide_disk_pre_reset() > because this flag must not be set after *any* sort of access to the > device. v4: Fix a memory leak due to a missing blk_put_request() in issue_park_cmd(). Additionally, we should plug the queue when enqueueing the unpark request because there is no guarantee that the park timeout has not expired by then. Even though the chance for that to happen is very slim, the request might end up hanging in the queue until the next I/O operation is queued up. While at it, clean up the code a little: - make issue_park_cmd() a function of type void since nobody cares for the return value anyway; - use blk_start_queueing() instead of __blk_run_queue() since we don't have to worry about recursion; - remove a superfluous pointer deference in task_no_data_intr(). Signed-off-by: Elias Oltmanns <eo@nebensachen.de> Cc: Jeff Garzik <jeff@garzik.org>, Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Tejun Heo <htejun@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2008-10-13 19:39:50 +00:00
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 = strict_strtol(buf, 10, &input);
if (rc || 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;
}