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md: use mddev->lock to protect updates to resync_{min,max}. 

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@suse.de>
hifive-unleashed-5.1
NeilBrown 2014-12-15 12:57:01 +11:00
parent 1b30e66f5a
commit 23da422b19
2 changed files with 47 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

58
drivers/md/md.c
View File

@ -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
*/

2
drivers/md/md.h
View File

@ -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 */