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md: Be more careful about clearing flags bit in ->recovery
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Setting ->recovery to 0 is generally not a good idea as it could clear
bits that shouldn't be cleared.  In particular, MD_RECOVERY_FROZEN
should only be cleared on explicit request from user-space.

So when we need to clear things, just clear the bits that need
clearing.

As there are a few different places which reap a resync process - and
some do an incomplte job - factor out the code for doing the from
md_check_recovery and call that function instead of open coding part
of it.

Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by: Jonathan Brassow <jbrassow@redhat.com>
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NeilBrown committed Jan 13, 2011
1 parent defad61 commit 7ebc0be
Showing 1 changed file with 49 additions and 37 deletions.
86 changes: 49 additions & 37 deletions drivers/md/md.c
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Original file line number Diff line number Diff line change
Expand Up @@ -3746,6 +3746,8 @@ action_show(mddev_t *mddev, char *page)
return sprintf(page, "%s\n", type);
}

static void reap_sync_thread(mddev_t *mddev);

static ssize_t
action_store(mddev_t *mddev, const char *page, size_t len)
{
Expand All @@ -3760,9 +3762,7 @@ action_store(mddev_t *mddev, const char *page, size_t len)
if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
if (mddev->sync_thread) {
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
md_unregister_thread(mddev->sync_thread);
mddev->sync_thread = NULL;
mddev->recovery = 0;
reap_sync_thread(mddev);
}
} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
Expand Down Expand Up @@ -4709,8 +4709,7 @@ static void __md_stop_writes(mddev_t *mddev)
if (mddev->sync_thread) {
set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
md_unregister_thread(mddev->sync_thread);
mddev->sync_thread = NULL;
reap_sync_thread(mddev);
}

del_timer_sync(&mddev->safemode_timer);
Expand Down Expand Up @@ -7044,6 +7043,45 @@ static int remove_and_add_spares(mddev_t *mddev)
}
return spares;
}

static void reap_sync_thread(mddev_t *mddev)
{
mdk_rdev_t *rdev;

/* resync has finished, collect result */
md_unregister_thread(mddev->sync_thread);
mddev->sync_thread = NULL;
if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
/* success...*/
/* activate any spares */
if (mddev->pers->spare_active(mddev))
sysfs_notify(&mddev->kobj, NULL,
"degraded");
}
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
mddev->pers->finish_reshape)
mddev->pers->finish_reshape(mddev);
md_update_sb(mddev, 1);

/* if array is no-longer degraded, then any saved_raid_disk
* information must be scrapped
*/
if (!mddev->degraded)
list_for_each_entry(rdev, &mddev->disks, same_set)
rdev->saved_raid_disk = -1;

clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
/* flag recovery needed just to double check */
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
sysfs_notify_dirent_safe(mddev->sysfs_action);
md_new_event(mddev);
}

/*
* This routine is regularly called by all per-raid-array threads to
* deal with generic issues like resync and super-block update.
Expand All @@ -7068,9 +7106,6 @@ static int remove_and_add_spares(mddev_t *mddev)
*/
void md_check_recovery(mddev_t *mddev)
{
mdk_rdev_t *rdev;


if (mddev->bitmap)
bitmap_daemon_work(mddev);

Expand Down Expand Up @@ -7138,34 +7173,7 @@ void md_check_recovery(mddev_t *mddev)
goto unlock;
}
if (mddev->sync_thread) {
/* resync has finished, collect result */
md_unregister_thread(mddev->sync_thread);
mddev->sync_thread = NULL;
if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
/* success...*/
/* activate any spares */
if (mddev->pers->spare_active(mddev))
sysfs_notify(&mddev->kobj, NULL,
"degraded");
}
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
mddev->pers->finish_reshape)
mddev->pers->finish_reshape(mddev);
md_update_sb(mddev, 1);

/* if array is no-longer degraded, then any saved_raid_disk
* information must be scrapped
*/
if (!mddev->degraded)
list_for_each_entry(rdev, &mddev->disks, same_set)
rdev->saved_raid_disk = -1;

mddev->recovery = 0;
/* flag recovery needed just to double check */
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
sysfs_notify_dirent_safe(mddev->sysfs_action);
md_new_event(mddev);
reap_sync_thread(mddev);
goto unlock;
}
/* Set RUNNING before clearing NEEDED to avoid
Expand Down Expand Up @@ -7223,7 +7231,11 @@ void md_check_recovery(mddev_t *mddev)
" thread...\n",
mdname(mddev));
/* leave the spares where they are, it shouldn't hurt */
mddev->recovery = 0;
clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
} else
md_wakeup_thread(mddev->sync_thread);
sysfs_notify_dirent_safe(mddev->sysfs_action);
Expand Down

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