path: root/drivers/md/dm-integrity.c
diff options
authorMikulas Patocka <mpatocka@redhat.com>2020-02-24 10:20:28 +0100
committerMike Snitzer <snitzer@redhat.com>2020-02-27 16:40:58 -0500
commitadc0daad366b62ca1bce3e2958a40b0b71a8b8b3 (patch)
tree03c033437b0699892741bb7363d99bdd2c864ed9 /drivers/md/dm-integrity.c
parentdm thin metadata: fix lockdep complaint (diff)
dm: report suspended device during destroy
The function dm_suspended returns true if the target is suspended. However, when the target is being suspended during unload, it returns false. An example where this is a problem: the test "!dm_suspended(wc->ti)" in writecache_writeback is not sufficient, because dm_suspended returns zero while writecache_suspend is in progress. As is, without an enhanced dm_suspended, simply switching from flush_workqueue to drain_workqueue still emits warnings: workqueue writecache-writeback: drain_workqueue() isn't complete after 10 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 100 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 200 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 300 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 400 tries writecache_suspend calls flush_workqueue(wc->writeback_wq) - this function flushes the current work. However, the workqueue may re-queue itself and flush_workqueue doesn't wait for re-queued works to finish. Because of this - the function writecache_writeback continues execution after the device was suspended and then concurrently with writecache_dtr, causing a crash in writecache_writeback. We must use drain_workqueue - that waits until the work and all re-queued works finish. As a prereq for switching to drain_workqueue, this commit fixes dm_suspended to return true after the presuspend hook and before the postsuspend hook - just like during a normal suspend. It allows simplifying the dm-integrity and dm-writecache targets so that they don't have to maintain suspended flags on their own. With this change use of drain_workqueue() can be used effectively. This change was tested with the lvm2 testsuite and cryptsetup testsuite and the are no regressions. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Reported-by: Corey Marthaler <cmarthal@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-integrity.c')
1 files changed, 5 insertions, 7 deletions
diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index 2f98e88399ec..e1ad0b53f681 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -201,12 +201,13 @@ struct dm_integrity_c {
__u8 log2_blocks_per_bitmap_bit;
unsigned char mode;
- int suspending;
int failed;
struct crypto_shash *internal_hash;
+ struct dm_target *ti;
/* these variables are locked with endio_wait.lock */
struct rb_root in_progress;
struct list_head wait_list;
@@ -2316,7 +2317,7 @@ static void integrity_writer(struct work_struct *w)
unsigned prev_free_sectors;
/* the following test is not needed, but it tests the replay code */
- if (READ_ONCE(ic->suspending) && !ic->meta_dev)
+ if (unlikely(dm_suspended(ic->ti)) && !ic->meta_dev)
@@ -2377,7 +2378,7 @@ static void integrity_recalc(struct work_struct *w)
- if (unlikely(READ_ONCE(ic->suspending)))
+ if (unlikely(dm_suspended(ic->ti)))
goto unlock_ret;
range.logical_sector = le64_to_cpu(ic->sb->recalc_sector);
@@ -2805,8 +2806,6 @@ static void dm_integrity_postsuspend(struct dm_target *ti)
- WRITE_ONCE(ic->suspending, 1);
if (ic->recalc_wq)
@@ -2835,8 +2834,6 @@ static void dm_integrity_postsuspend(struct dm_target *ti)
- WRITE_ONCE(ic->suspending, 0);
ic->journal_uptodate = true;
@@ -3631,6 +3628,7 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
ti->private = ic;
ti->per_io_data_size = sizeof(struct dm_integrity_io);
+ ic->ti = ti;
ic->in_progress = RB_ROOT;