From b0519b542303bc167d22bf11dadd3f18d37dbfe2 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 27 Nov 2020 16:21:42 +0100 Subject: [PATCH] dm: remove the block_device reference in struct mapped_device Get rid of the long-lasting struct block_device reference in struct mapped_device. The only remaining user is the freeze code, where we can trivially look up the block device at freeze time and release the reference at thaw time. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Acked-by: Mike Snitzer Signed-off-by: Jens Axboe --- drivers/md/dm-core.h | 2 -- drivers/md/dm.c | 25 ++++++++++++++----------- 2 files changed, 14 insertions(+), 13 deletions(-) diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h index aace147effca..086d293c2b03 100644 --- a/drivers/md/dm-core.h +++ b/drivers/md/dm-core.h @@ -102,8 +102,6 @@ struct mapped_device { /* kobject and completion */ struct dm_kobject_holder kobj_holder; - struct block_device *bdev; - struct dm_stats stats; /* for blk-mq request-based DM support */ diff --git a/drivers/md/dm.c b/drivers/md/dm.c index ab0a8335f098..48051db006f3 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1744,11 +1744,6 @@ static void cleanup_mapped_device(struct mapped_device *md) cleanup_srcu_struct(&md->io_barrier); - if (md->bdev) { - bdput(md->bdev); - md->bdev = NULL; - } - mutex_destroy(&md->suspend_lock); mutex_destroy(&md->type_lock); mutex_destroy(&md->table_devices_lock); @@ -1840,10 +1835,6 @@ static struct mapped_device *alloc_dev(int minor) if (!md->wq) goto bad; - md->bdev = bdget_disk(md->disk, 0); - if (!md->bdev) - goto bad; - dm_stats_init(&md->stats); /* Populate the mapping, nobody knows we exist yet */ @@ -2384,11 +2375,16 @@ out: */ static int lock_fs(struct mapped_device *md) { + struct block_device *bdev; int r; WARN_ON(test_bit(DMF_FROZEN, &md->flags)); - r = freeze_bdev(md->bdev); + bdev = bdget_disk(md->disk, 0); + if (!bdev) + return -ENOMEM; + r = freeze_bdev(bdev); + bdput(bdev); if (!r) set_bit(DMF_FROZEN, &md->flags); return r; @@ -2396,9 +2392,16 @@ static int lock_fs(struct mapped_device *md) static void unlock_fs(struct mapped_device *md) { + struct block_device *bdev; + if (!test_bit(DMF_FROZEN, &md->flags)) return; - thaw_bdev(md->bdev); + + bdev = bdget_disk(md->disk, 0); + if (!bdev) + return; + thaw_bdev(bdev); + bdput(bdev); clear_bit(DMF_FROZEN, &md->flags); }