* [PATCH v3 0/2] Update SCSI target removal path
@ 2016-03-31 12:53 Johannes Thumshirn
2016-03-31 12:53 ` [PATCH v3 1/2] scsi: Add intermediate STARGET_REMOVE state to scsi_target_state Johannes Thumshirn
2016-03-31 12:53 ` [PATCH v3 2/2] Revert "scsi: fix soft lockup in scsi_remove_target() on module removal" Johannes Thumshirn
0 siblings, 2 replies; 7+ messages in thread
From: Johannes Thumshirn @ 2016-03-31 12:53 UTC (permalink / raw)
To: Martin K. Petersen, James E.J. Bottomley
Cc: Ewan D. Milne, Hannes Reinecke, Christoph Hellwig,
Johannes Thumshirn, linux-scsi, linux-kernel
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
^ permalink raw reply [flat|nested] 7+ messages in thread* [PATCH v3 1/2] scsi: Add intermediate STARGET_REMOVE state to scsi_target_state 2016-03-31 12:53 [PATCH v3 0/2] Update SCSI target removal path Johannes Thumshirn @ 2016-03-31 12:53 ` Johannes Thumshirn 2016-03-31 16:17 ` Hannes Reinecke 2016-04-02 16:36 ` James Bottomley 2016-03-31 12:53 ` [PATCH v3 2/2] Revert "scsi: fix soft lockup in scsi_remove_target() on module removal" Johannes Thumshirn 1 sibling, 2 replies; 7+ messages in thread From: Johannes Thumshirn @ 2016-03-31 12:53 UTC (permalink / raw) To: Martin K. Petersen, James E.J. Bottomley Cc: Ewan D. Milne, Hannes Reinecke, Christoph Hellwig, Johannes Thumshirn, linux-scsi, linux-kernel 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 <jthumshirn@suse.de> 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 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v3 1/2] scsi: Add intermediate STARGET_REMOVE state to scsi_target_state 2016-03-31 12:53 ` [PATCH v3 1/2] scsi: Add intermediate STARGET_REMOVE state to scsi_target_state Johannes Thumshirn @ 2016-03-31 16:17 ` Hannes Reinecke 2016-04-02 16:36 ` James Bottomley 1 sibling, 0 replies; 7+ messages in thread From: Hannes Reinecke @ 2016-03-31 16:17 UTC (permalink / raw) To: Johannes Thumshirn, Martin K. Petersen, James E.J. Bottomley Cc: Ewan D. Milne, Christoph Hellwig, linux-scsi, linux-kernel 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 <jthumshirn@suse.de> > 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 <hare@suse.com> Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg) ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v3 1/2] scsi: Add intermediate STARGET_REMOVE state to scsi_target_state 2016-03-31 12:53 ` [PATCH v3 1/2] scsi: Add intermediate STARGET_REMOVE state to scsi_target_state Johannes Thumshirn 2016-03-31 16:17 ` Hannes Reinecke @ 2016-04-02 16:36 ` James Bottomley 2016-04-04 9:39 ` Johannes Thumshirn 1 sibling, 1 reply; 7+ messages in thread From: James Bottomley @ 2016-04-02 16:36 UTC (permalink / raw) To: Johannes Thumshirn, Martin K. Petersen Cc: Ewan D. Milne, Hannes Reinecke, Christoph Hellwig, linux-scsi, linux-kernel 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 <jthumshirn@suse.de> > Fixes: 40998193560dab6c3ce8d25f4fa58a23e252ef38 The code and ordering is fine with me, so you can add Reviewed-by: James Bottomley <jejb@linux.vnet.ibm.com> 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 ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v3 1/2] scsi: Add intermediate STARGET_REMOVE state to scsi_target_state 2016-04-02 16:36 ` James Bottomley @ 2016-04-04 9:39 ` Johannes Thumshirn 0 siblings, 0 replies; 7+ messages in thread From: Johannes Thumshirn @ 2016-04-04 9:39 UTC (permalink / raw) To: James Bottomley Cc: Martin K. Petersen, Ewan D. Milne, Hannes Reinecke, Christoph Hellwig, linux-scsi, linux-kernel, linux-scsi-owner 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 <jthumshirn@suse.de> >> Fixes: 40998193560dab6c3ce8d25f4fa58a23e252ef38 > > The code and ordering is fine with me, so you can add > > Reviewed-by: James Bottomley <jejb@linux.vnet.ibm.com> > > 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. ^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v3 2/2] Revert "scsi: fix soft lockup in scsi_remove_target() on module removal" 2016-03-31 12:53 [PATCH v3 0/2] Update SCSI target removal path Johannes Thumshirn 2016-03-31 12:53 ` [PATCH v3 1/2] scsi: Add intermediate STARGET_REMOVE state to scsi_target_state Johannes Thumshirn @ 2016-03-31 12:53 ` Johannes Thumshirn 2016-03-31 16:18 ` Hannes Reinecke 1 sibling, 1 reply; 7+ messages in thread From: Johannes Thumshirn @ 2016-03-31 12:53 UTC (permalink / raw) To: Martin K. Petersen, James E.J. Bottomley Cc: Ewan D. Milne, Hannes Reinecke, Christoph Hellwig, Johannes Thumshirn, linux-scsi, linux-kernel This reverts commit 90a88d6ef88edcfc4f644dddc7eef4ea41bccf8b. Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> --- 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 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v3 2/2] Revert "scsi: fix soft lockup in scsi_remove_target() on module removal" 2016-03-31 12:53 ` [PATCH v3 2/2] Revert "scsi: fix soft lockup in scsi_remove_target() on module removal" Johannes Thumshirn @ 2016-03-31 16:18 ` Hannes Reinecke 0 siblings, 0 replies; 7+ messages in thread From: Hannes Reinecke @ 2016-03-31 16:18 UTC (permalink / raw) To: Johannes Thumshirn, Martin K. Petersen, James E.J. Bottomley Cc: Ewan D. Milne, Christoph Hellwig, linux-scsi, linux-kernel On 03/31/2016 02:53 PM, Johannes Thumshirn wrote: > This reverts commit 90a88d6ef88edcfc4f644dddc7eef4ea41bccf8b. > > Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> > --- > drivers/scsi/scsi_sysfs.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > Reviewed-by: Hannes Reinecke <hare@suse.com> Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg) ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2016-04-04 9:39 UTC | newest] Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2016-03-31 12:53 [PATCH v3 0/2] Update SCSI target removal path Johannes Thumshirn 2016-03-31 12:53 ` [PATCH v3 1/2] scsi: Add intermediate STARGET_REMOVE state to scsi_target_state Johannes Thumshirn 2016-03-31 16:17 ` Hannes Reinecke 2016-04-02 16:36 ` James Bottomley 2016-04-04 9:39 ` Johannes Thumshirn 2016-03-31 12:53 ` [PATCH v3 2/2] Revert "scsi: fix soft lockup in scsi_remove_target() on module removal" Johannes Thumshirn 2016-03-31 16:18 ` Hannes Reinecke
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