[PATCH 12/24] aoe: don't call set_capacity from irq context

Christoph Hellwig
2020-11-06T19:04:45Z

Updating the block device size from irq context can lead to torn
writes of the 64-bit value, and prevents us from using normal
process context locking primitives to serialize access to the 64-bit
nr_sectors value. Defer the set_capacity to the already existing
workqueue handler, where it can be merged with the update of the
block device size by using set_capacity_and_notify. As an extra
bonus this also adds proper uevent notifications for the resize.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/block/aoe/aoecmd.c | 15 ++++-----------
1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index 313f0b946fe2b3..ac720bdcd983e7 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -890,19 +890,13 @@ void
aoecmd_sleepwork(struct work_struct *work)
{
struct aoedev *d = container_of(work, struct aoedev, work);
- struct block_device *bd;
- u64 ssize;

if (d->flags & DEVFL_GDALLOC)
aoeblk_gdalloc(d);

if (d->flags & DEVFL_NEWSIZE) {
- ssize = get_capacity(d->gd);
- bd = bdget_disk(d->gd, 0);
- if (bd) {
- bd_set_nr_sectors(bd, ssize);
- bdput(bd);
- }
+ set_capacity_and_notify(d->gd, d->ssize);
+
spin_lock_irq(&d->lock);
d->flags |= DEVFL_UP;
d->flags &= ~DEVFL_NEWSIZE;
@@ -971,10 +965,9 @@ ataid_complete(struct aoedev *d, struct aoetgt *t, unsigned char *id)
d->geo.start = 0;
if (d->flags & (DEVFL_GDALLOC|DEVFL_NEWSIZE))
return;
- if (d->gd != NULL) {
- set_capacity(d->gd, ssize);
+ if (d->gd != NULL)
d->flags |= DEVFL_NEWSIZE;
- } else
+ else
d->flags |= DEVFL_GDALLOC;
schedule_work(&d->work);