* [RFC][PATCH v4 3/3] efi_pstore: Skiping scheduling a workqueue in cases other than oops
@ 2012-08-21 20:36 Seiji Aguchi
0 siblings, 0 replies; only message in thread
From: Seiji Aguchi @ 2012-08-21 20:36 UTC (permalink / raw)
To: Mike Waychison, linux-kernel, Luck, Tony (tony.luck@intel.com),
Matthew Garrett (mjg@redhat.com),
dzickus
Cc: dle-develop, Satoru Moriya
[Problem]
efi_pstore creates sysfs files when logging kernel messages to NVRAM.
Currently, the sysfs files are updated in a workqueue which is registered in a write callback.
On the other hand, situations which users needs the sysfs files are when they erase entries or oops happen
because a system will be down and users can't access to sysfs files in other cases like panic, reboot or emergency_restart.
Also, if kernel panics due to a bug of workqueue operations and a write callback of efi_pstore is called in
panic case, efi_pstore may fail due to a failure of schedule_work().
And panic_notifier_chain()/emergency_restart() is not kicked if efi_pstore fails.
This may cause user's unwanted result.
[Patch Description]
This patch registers a workqueue updating sysfs entries in cases where users erase entries or oops happen only,
and skips it in other cases like panic, reboot or emergency_start.
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
---
drivers/firmware/efivars.c | 7 ++++++-
1 files changed, 6 insertions(+), 1 deletions(-)
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index cd16ea6..d5911fd 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -746,7 +746,12 @@ static int efi_pstore_write(enum pstore_type_id type,
spin_unlock_irqrestore(&efivars->lock, flags);
- schedule_work(&efivar_work);
+ /*
+ * The user may want to update sysfs for this write
+ * when they erase an entry via /dev/pstore or oops happen.
+ */
+ if (!size || reason == KMSG_DUMP_OOPS)
+ schedule_work(&efivar_work);
*id = part;
return ret;
-- 1.7.1
^ permalink raw reply related [flat|nested] only message in thread
only message in thread, other threads:[~2012-08-21 20:37 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-08-21 20:36 [RFC][PATCH v4 3/3] efi_pstore: Skiping scheduling a workqueue in cases other than oops Seiji Aguchi
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).