This is a follow up to "scsi: Add intermediate STARGET_REMOVE state to
scsi_target_state".
If anyone has an idea how to create a regression test suite for the target
removal path I'd be all ears, given the fact that this is the 3rd or 4th patch
targeting it.
Changes to v2:
* Reverse the order of patches as pointed out by James
Changes to v1:
* Fix error (hit BUG_ON()) discovered by the 0-Day bot.
* Revert "scsi: fix soft lockup in scsi_remove_target() on module removal"
Johannes Thumshirn (2):
scsi: Add intermediate STARGET_REMOVE state to scsi_target_state
Revert "scsi: fix soft lockup in scsi_remove_target() on module
removal"
drivers/scsi/scsi_scan.c | 2 ++
drivers/scsi/scsi_sysfs.c | 6 +++---
include/scsi/scsi_device.h | 1 +
3 files changed, 6 insertions(+), 3 deletions(-)
--
1.8.5.6
Add intermediate STARGET_REMOVE state to scsi_target_state to avoid running
into the BUG_ON() in scsi_target_reap().
This intermediate state is only valid in the path from scsi_remove_target() to
scsi_target_destroy() indicating this target is going to be removed.
Signed-off-by: Johannes Thumshirn <[email protected]>
Fixes: 40998193560dab6c3ce8d25f4fa58a23e252ef38
---
drivers/scsi/scsi_scan.c | 2 ++
drivers/scsi/scsi_sysfs.c | 2 ++
include/scsi/scsi_device.h | 1 +
3 files changed, 5 insertions(+)
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 6a82066..63b8bca 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -315,6 +315,8 @@ static void scsi_target_destroy(struct scsi_target *starget)
struct Scsi_Host *shost = dev_to_shost(dev->parent);
unsigned long flags;
+ BUG_ON(starget->state != STARGET_REMOVE &&
+ starget->state != STARGET_CREATED);
starget->state = STARGET_DEL;
transport_destroy_device(dev);
spin_lock_irqsave(shost->host_lock, flags);
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 00bc721..0df82e8 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1279,11 +1279,13 @@ restart:
spin_lock_irqsave(shost->host_lock, flags);
list_for_each_entry(starget, &shost->__targets, siblings) {
if (starget->state == STARGET_DEL ||
+ starget->state == STARGET_REMOVE ||
starget == last_target)
continue;
if (starget->dev.parent == dev || &starget->dev == dev) {
kref_get(&starget->reap_ref);
last_target = starget;
+ starget->state = STARGET_REMOVE;
spin_unlock_irqrestore(shost->host_lock, flags);
__scsi_remove_target(starget);
scsi_target_reap(starget);
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index f63a167..2bffaa6 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -240,6 +240,7 @@ scmd_printk(const char *, const struct scsi_cmnd *, const char *, ...);
enum scsi_target_state {
STARGET_CREATED = 1,
STARGET_RUNNING,
+ STARGET_REMOVE,
STARGET_DEL,
};
--
1.8.5.6
This reverts commit 90a88d6ef88edcfc4f644dddc7eef4ea41bccf8b.
Signed-off-by: Johannes Thumshirn <[email protected]>
---
drivers/scsi/scsi_sysfs.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 0df82e8..9e5f893 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1272,19 +1272,17 @@ static void __scsi_remove_target(struct scsi_target *starget)
void scsi_remove_target(struct device *dev)
{
struct Scsi_Host *shost = dev_to_shost(dev->parent);
- struct scsi_target *starget, *last_target = NULL;
+ struct scsi_target *starget;
unsigned long flags;
restart:
spin_lock_irqsave(shost->host_lock, flags);
list_for_each_entry(starget, &shost->__targets, siblings) {
if (starget->state == STARGET_DEL ||
- starget->state == STARGET_REMOVE ||
- starget == last_target)
+ starget->state == STARGET_REMOVE)
continue;
if (starget->dev.parent == dev || &starget->dev == dev) {
kref_get(&starget->reap_ref);
- last_target = starget;
starget->state = STARGET_REMOVE;
spin_unlock_irqrestore(shost->host_lock, flags);
__scsi_remove_target(starget);
--
1.8.5.6
On 03/31/2016 02:53 PM, Johannes Thumshirn wrote:
> Add intermediate STARGET_REMOVE state to scsi_target_state to avoid running
> into the BUG_ON() in scsi_target_reap().
>
> This intermediate state is only valid in the path from scsi_remove_target() to
> scsi_target_destroy() indicating this target is going to be removed.
>
> Signed-off-by: Johannes Thumshirn <[email protected]>
> Fixes: 40998193560dab6c3ce8d25f4fa58a23e252ef38
> ---
> drivers/scsi/scsi_scan.c | 2 ++
> drivers/scsi/scsi_sysfs.c | 2 ++
> include/scsi/scsi_device.h | 1 +
> 3 files changed, 5 insertions(+)
>
> diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
> index 6a82066..63b8bca 100644
> --- a/drivers/scsi/scsi_scan.c
> +++ b/drivers/scsi/scsi_scan.c
> @@ -315,6 +315,8 @@ static void scsi_target_destroy(struct scsi_target *starget)
> struct Scsi_Host *shost = dev_to_shost(dev->parent);
> unsigned long flags;
>
> + BUG_ON(starget->state != STARGET_REMOVE &&
> + starget->state != STARGET_CREATED);
> starget->state = STARGET_DEL;
> transport_destroy_device(dev);
> spin_lock_irqsave(shost->host_lock, flags);
> diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
> index 00bc721..0df82e8 100644
> --- a/drivers/scsi/scsi_sysfs.c
> +++ b/drivers/scsi/scsi_sysfs.c
> @@ -1279,11 +1279,13 @@ restart:
> spin_lock_irqsave(shost->host_lock, flags);
> list_for_each_entry(starget, &shost->__targets, siblings) {
> if (starget->state == STARGET_DEL ||
> + starget->state == STARGET_REMOVE ||
> starget == last_target)
> continue;
> if (starget->dev.parent == dev || &starget->dev == dev) {
> kref_get(&starget->reap_ref);
> last_target = starget;
> + starget->state = STARGET_REMOVE;
> spin_unlock_irqrestore(shost->host_lock, flags);
> __scsi_remove_target(starget);
> scsi_target_reap(starget);
> diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
> index f63a167..2bffaa6 100644
> --- a/include/scsi/scsi_device.h
> +++ b/include/scsi/scsi_device.h
> @@ -240,6 +240,7 @@ scmd_printk(const char *, const struct scsi_cmnd *, const char *, ...);
> enum scsi_target_state {
> STARGET_CREATED = 1,
> STARGET_RUNNING,
> + STARGET_REMOVE,
> STARGET_DEL,
> };
>
>
Reviewed-by: Hannes Reinecke <[email protected]>
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
[email protected] +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N?rnberg
GF: J. Hawn, J. Guild, F. Imend?rffer, HRB 16746 (AG N?rnberg)
On 03/31/2016 02:53 PM, Johannes Thumshirn wrote:
> This reverts commit 90a88d6ef88edcfc4f644dddc7eef4ea41bccf8b.
>
> Signed-off-by: Johannes Thumshirn <[email protected]>
> ---
> drivers/scsi/scsi_sysfs.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
Reviewed-by: Hannes Reinecke <[email protected]>
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
[email protected] +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N?rnberg
GF: J. Hawn, J. Guild, F. Imend?rffer, HRB 16746 (AG N?rnberg)
On Thu, 2016-03-31 at 14:53 +0200, Johannes Thumshirn wrote:
> Add intermediate STARGET_REMOVE state to scsi_target_state to avoid
> running
> into the BUG_ON() in scsi_target_reap().
>
> This intermediate state is only valid in the path from
> scsi_remove_target() to
> scsi_target_destroy() indicating this target is going to be removed.
>
> Signed-off-by: Johannes Thumshirn <[email protected]>
> Fixes: 40998193560dab6c3ce8d25f4fa58a23e252ef38
The code and ordering is fine with me, so you can add
Reviewed-by: James Bottomley <[email protected]>
However, I'd really appreciate it if the description of what was going
on was clearer for a non-SUSE distro maintainer. What we're doing is
applying a more comprehensive fix for a previously hack fixed problem
and then reverting the hack. I think message 1 should say "this
refixes the problem introduced by commit X in a more comprehensive way"
and message 2 "Now that we've done a more comprehensive fix with the
intermediate target state in patch Y, we can remove the previous hack"
James
On 2016-04-02 18:36, James Bottomley wrote:
> On Thu, 2016-03-31 at 14:53 +0200, Johannes Thumshirn wrote:
>> Add intermediate STARGET_REMOVE state to scsi_target_state to avoid
>> running
>> into the BUG_ON() in scsi_target_reap().
>>
>> This intermediate state is only valid in the path from
>> scsi_remove_target() to
>> scsi_target_destroy() indicating this target is going to be removed.
>>
>> Signed-off-by: Johannes Thumshirn <[email protected]>
>> Fixes: 40998193560dab6c3ce8d25f4fa58a23e252ef38
>
> The code and ordering is fine with me, so you can add
>
> Reviewed-by: James Bottomley <[email protected]>
>
> However, I'd really appreciate it if the description of what was going
> on was clearer for a non-SUSE distro maintainer. What we're doing is
> applying a more comprehensive fix for a previously hack fixed problem
> and then reverting the hack. I think message 1 should say "this
> refixes the problem introduced by commit X in a more comprehensive way"
>
> and message 2 "Now that we've done a more comprehensive fix with the
> intermediate target state in patch Y, we can remove the previous hack"
>
> James
OK, I'll try my very best. Thanks for the review.