Merge tag 'for-6.3/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device...

Pull device mapper fixes from Mike Snitzer:

 - Fix DM thin to work as a swap device by using 'limit_swap_bios' DM
   target flag (initially added to allow swap to dm-crypt) to throttle
   the amount of outstanding swap bios.

 - Fix DM crypt soft lockup warnings by calling cond_resched() from the
   cpu intensive loop in dmcrypt_write().

 - Fix DM crypt to not access an uninitialized tasklet. This fix allows
   for consistent handling of IO completion, by _not_ needlessly punting
   to a workqueue when tasklets are not needed.

 - Fix DM core's alloc_dev() initialization for DM stats to check for
   and propagate alloc_percpu() failure.

* tag 'for-6.3/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm stats: check for and propagate alloc_percpu failure
  dm crypt: avoid accessing uninitialized tasklet
  dm crypt: add cond_resched() to dmcrypt_write()
  dm thin: fix deadlock when swapping to thin device

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 40cb171..3ba53dc 100644 (file)
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -72,7 +72,9 @@ struct dm_crypt_io {
        struct crypt_config *cc;
        struct bio *base_bio;
        u8 *integrity_metadata;
-       bool integrity_metadata_from_pool;
+       bool integrity_metadata_from_pool:1;
+       bool in_tasklet:1;
+
        struct work_struct work;
        struct tasklet_struct tasklet;
 
@@ -1730,6 +1732,7 @@ static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
        io->ctx.r.req = NULL;
        io->integrity_metadata = NULL;
        io->integrity_metadata_from_pool = false;
+       io->in_tasklet = false;
        atomic_set(&io->io_pending, 0);
 }
 
@@ -1776,14 +1779,13 @@ static void crypt_dec_pending(struct dm_crypt_io *io)
         * our tasklet. In this case we need to delay bio_endio()
         * execution to after the tasklet is done and dequeued.
         */
-       if (tasklet_trylock(&io->tasklet)) {
-               tasklet_unlock(&io->tasklet);
-               bio_endio(base_bio);
+       if (io->in_tasklet) {
+               INIT_WORK(&io->work, kcryptd_io_bio_endio);
+               queue_work(cc->io_queue, &io->work);
                return;
        }
 
-       INIT_WORK(&io->work, kcryptd_io_bio_endio);
-       queue_work(cc->io_queue, &io->work);
+       bio_endio(base_bio);
 }
 
 /*
@@ -1936,6 +1938,7 @@ pop_from_list:
                        io = crypt_io_from_node(rb_first(&write_tree));
                        rb_erase(&io->rb_node, &write_tree);
                        kcryptd_io_write(io);
+                       cond_resched();
                } while (!RB_EMPTY_ROOT(&write_tree));
                blk_finish_plug(&plug);
        }
@@ -2230,6 +2233,7 @@ static void kcryptd_queue_crypt(struct dm_crypt_io *io)
                 * it is being executed with irqs disabled.
                 */
                if (in_hardirq() || irqs_disabled()) {
+                       io->in_tasklet = true;
                        tasklet_init(&io->tasklet, kcryptd_crypt_tasklet, (unsigned long)&io->work);
                        tasklet_schedule(&io->tasklet);
                        return;

diff --git a/drivers/md/dm-stats.c b/drivers/md/dm-stats.c
index c21a19a..db2d997 100644 (file)
--- a/drivers/md/dm-stats.c
+++ b/drivers/md/dm-stats.c
@@ -188,7 +188,7 @@ static int dm_stat_in_flight(struct dm_stat_shared *shared)
               atomic_read(&shared->in_flight[WRITE]);
 }
 
-void dm_stats_init(struct dm_stats *stats)
+int dm_stats_init(struct dm_stats *stats)
 {
        int cpu;
        struct dm_stats_last_position *last;
@@ -197,11 +197,16 @@ void dm_stats_init(struct dm_stats *stats)
        INIT_LIST_HEAD(&stats->list);
        stats->precise_timestamps = false;
        stats->last = alloc_percpu(struct dm_stats_last_position);
+       if (!stats->last)
+               return -ENOMEM;
+
        for_each_possible_cpu(cpu) {
                last = per_cpu_ptr(stats->last, cpu);
                last->last_sector = (sector_t)ULLONG_MAX;
                last->last_rw = UINT_MAX;
        }
+
+       return 0;
 }
 
 void dm_stats_cleanup(struct dm_stats *stats)

diff --git a/drivers/md/dm-stats.h b/drivers/md/dm-stats.h
index 0bc152c..c6728c8 100644 (file)
--- a/drivers/md/dm-stats.h
+++ b/drivers/md/dm-stats.h
@@ -21,7 +21,7 @@ struct dm_stats_aux {
        unsigned long long duration_ns;
 };
 
-void dm_stats_init(struct dm_stats *st);
+int dm_stats_init(struct dm_stats *st);
 void dm_stats_cleanup(struct dm_stats *st);
 
 struct mapped_device;

diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 6cd105c..13d4677 100644 (file)
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -3369,6 +3369,7 @@ static int pool_ctr(struct dm_target *ti, unsigned int argc, char **argv)
        pt->low_water_blocks = low_water_blocks;
        pt->adjusted_pf = pt->requested_pf = pf;
        ti->num_flush_bios = 1;
+       ti->limit_swap_bios = true;
 
        /*
         * Only need to enable discards if the pool should pass
@@ -4249,6 +4250,7 @@ static int thin_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                goto bad;
 
        ti->num_flush_bios = 1;
+       ti->limit_swap_bios = true;
        ti->flush_supported = true;
        ti->accounts_remapped_io = true;
        ti->per_io_data_size = sizeof(struct dm_thin_endio_hook);

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index f5cc330..2d0f934 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2097,7 +2097,9 @@ static struct mapped_device *alloc_dev(int minor)
        if (!md->pending_io)
                goto bad;
 
-       dm_stats_init(&md->stats);
+       r = dm_stats_init(&md->stats);
+       if (r < 0)
+               goto bad;
 
        /* Populate the mapping, nobody knows we exist yet */
        spin_lock(&_minor_lock);