The patch titled
md: delay starting md threads until array is completely setup
has been added to the -mm tree. Its filename is
md-delay-starting-md-threads-until-array-is-completely-setup.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: md: delay starting md threads until array is completely setup
From: NeilBrown <neilb@xxxxxxx>
When an array is started we start one or two threads (two if there is a
reshape or recovery that needs to be completed).
We currently start these *before* the array is completely set up and in
particular before queue->queuedata is set. If the thread actually starts
very quickly on another CPU, we can end up dereferencing queue->queuedata
and oops.
This patch also makes sure we don't try to start a recovery if a reshape is
being restarted.
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/md/md.c | 8 ++++----
drivers/md/raid5.c | 3 ---
2 files changed, 4 insertions(+), 7 deletions(-)
diff -puN drivers/md/md.c~md-delay-starting-md-threads-until-array-is-completely-setup drivers/md/md.c
--- a/drivers/md/md.c~md-delay-starting-md-threads-until-array-is-completely-setup
+++ a/drivers/md/md.c
@@ -3100,7 +3100,6 @@ static int do_md_run(mddev_t * mddev)
}
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
- md_wakeup_thread(mddev->thread);
if (mddev->sb_dirty)
md_update_sb(mddev);
@@ -3121,7 +3120,7 @@ static int do_md_run(mddev_t * mddev)
* start recovery here. If we leave it to md_check_recovery,
* it will remove the drives and not do the right thing
*/
- if (mddev->degraded) {
+ if (mddev->degraded && !mddev->sync_thread) {
struct list_head *rtmp;
int spares = 0;
ITERATE_RDEV(mddev,rdev,rtmp)
@@ -3142,10 +3141,11 @@ static int do_md_run(mddev_t * mddev)
mdname(mddev));
/* leave the spares where they are, it shouldn't hurt */
mddev->recovery = 0;
- } else
- md_wakeup_thread(mddev->sync_thread);
+ }
}
}
+ md_wakeup_thread(mddev->thread);
+ md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
mddev->changed = 1;
md_new_event(mddev);
diff -puN drivers/md/raid5.c~md-delay-starting-md-threads-until-array-is-completely-setup drivers/md/raid5.c
--- a/drivers/md/raid5.c~md-delay-starting-md-threads-until-array-is-completely-setup
+++ a/drivers/md/raid5.c
@@ -3247,9 +3247,6 @@ static int run(mddev_t *mddev)
set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
mddev->sync_thread = md_register_thread(md_do_sync, mddev,
"%s_reshape");
- /* FIXME if md_register_thread fails?? */
- md_wakeup_thread(mddev->sync_thread);
-
}
/* read-ahead size must cover two whole stripes, which is
_
Patches currently in -mm which might be from neilb@xxxxxxx are
origin.patch
generic_file_buffered_write-deadlock-on-vectored-write.patch
md-possible-fix-for-unplug-problem.patch
md-set-desc_nr-correctly-for-version-1-superblocks.patch
md-delay-starting-md-threads-until-array-is-completely-setup.patch
md-fix-resync-speed-calculation-for-restarted-resyncs.patch
md-fix-a-plug-unplug-race-in-raid5.patch
md-fix-some-small-races-in-bitmap-plugging-in-raid5.patch
md-fix-usage-of-wrong-variable-in-raid1.patch
md-unify-usage-of-symbolic-names-for-perms.patch
md-require-cap_sys_admin-for-re-configuring-md-devices-via-sysfs.patch
md-fix-will-configure-message-when-interpreting-md=-kernel-parameter.patch
md-include-sector-number-in-messages-about-corrected-read-errors.patch
md-dm-reduce-stack-usage-with-stacked-block-devices.patch
lockdep-annotate-sunrpc-code.patch
-
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