There are interdependencies between these two sysfs attributes
and whether a resync is currently running.
Rather than depending on reconfig_mutex to ensure no races when
testing these interdependencies are met, use the spinlock.
This will allow the mutex to be remove from protecting this
code in a subsequent patch.
Signed-off-by: NeilBrown <neilb@xxxxxxx>
---
drivers/md/md.c | 58 +++++++++++++++++++++++++++++++++++++++++++------------
drivers/md/md.h | 2 ++
2 files changed, 47 insertions(+), 13 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index e68824d2d21e..c17de6d0fb42 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -4269,22 +4269,36 @@ static ssize_t
min_sync_store(struct mddev *mddev, const char *buf, size_t len)
{
unsigned long long min;
+ int err;
+ int chunk;
+
if (kstrtoull(buf, 10, &min))
return -EINVAL;
+
+ spin_lock(&mddev->lock);
+ err = -EINVAL;
if (min > mddev->resync_max)
- return -EINVAL;
+ goto out_unlock;
+
+ err = -EBUSY;
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
- return -EBUSY;
+ goto out_unlock;
/* Must be a multiple of chunk_size */
- if (mddev->chunk_sectors) {
+ chunk = mddev->chunk_sectors;
+ if (chunk) {
sector_t temp = min;
- if (sector_div(temp, mddev->chunk_sectors))
- return -EINVAL;
+
+ err = -EINVAL;
+ if (sector_div(temp, chunk))
+ goto out_unlock;
}
mddev->resync_min = min;
+ err = 0;
- return len;
+out_unlock:
+ spin_unlock(&mddev->lock);
+ return err ?: len;
}
static struct md_sysfs_entry md_min_sync =
@@ -4302,29 +4316,42 @@ max_sync_show(struct mddev *mddev, char *page)
static ssize_t
max_sync_store(struct mddev *mddev, const char *buf, size_t len)
{
+ int err;
+ spin_lock(&mddev->lock);
if (strncmp(buf, "max", 3) == 0)
mddev->resync_max = MaxSector;
else {
unsigned long long max;
+ int chunk;
+
+ err = -EINVAL;
if (kstrtoull(buf, 10, &max))
- return -EINVAL;
+ goto out_unlock;
if (max < mddev->resync_min)
- return -EINVAL;
+ goto out_unlock;
+
+ err = -EBUSY;
if (max < mddev->resync_max &&
mddev->ro == 0 &&
test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
- return -EBUSY;
+ goto out_unlock;
/* Must be a multiple of chunk_size */
- if (mddev->chunk_sectors) {
+ chunk = mddev->chunk_sectors;
+ if (chunk) {
sector_t temp = max;
- if (sector_div(temp, mddev->chunk_sectors))
- return -EINVAL;
+
+ err = -EINVAL;
+ if (sector_div(temp, chunk))
+ goto out_unlock;
}
mddev->resync_max = max;
}
wake_up(&mddev->recovery_wait);
- return len;
+ err = 0;
+out_unlock:
+ spin_unlock(&mddev->lock);
+ return err ?: len;
}
static struct md_sysfs_entry md_max_sync =
@@ -7585,6 +7612,7 @@ void md_do_sync(struct md_thread *thread)
skip:
set_bit(MD_CHANGE_DEVS, &mddev->flags);
+ spin_lock(&mddev->lock);
if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
/* We completed so min/max setting can be forgotten if used. */
if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
@@ -7593,6 +7621,8 @@ void md_do_sync(struct md_thread *thread)
} else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
mddev->resync_min = mddev->curr_resync_completed;
mddev->curr_resync = 0;
+ spin_unlock(&mddev->lock);
+
wake_up(&resync_wait);
set_bit(MD_RECOVERY_DONE, &mddev->recovery);
md_wakeup_thread(mddev->thread);
@@ -7793,7 +7823,9 @@ void md_check_recovery(struct mddev *mddev)
* any transients in the value of "sync_action".
*/
mddev->curr_resync_completed = 0;
+ spin_lock(&mddev->lock);
set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
+ spin_unlock(&mddev->lock);
/* Clear some bits that don't mean anything, but
* might be left set
*/
diff --git a/drivers/md/md.h b/drivers/md/md.h
index b4fbd6a63fcf..6bf3faa951ec 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -394,6 +394,8 @@ struct mddev {
* pers (also protected by reconfig_mutex and pending IO).
* clearing ->bitmap
* clearing ->bitmap_info.file
+ * changing ->resync_{min,max}
+ * setting MD_RECOVERY_RUNNING (which interacts with resync_{min,max})
*/
spinlock_t lock;
wait_queue_head_t sb_wait; /* for waiting on superblock updates */
--
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