From 96ebd8584aaa9b0f4eac8a922766c900a7495426 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 10 Jun 2015 23:47:14 -0400 Subject: [PATCH] block: fix ext_dev_lock lockdep report commit 4d66e5e9b6d720d8463e11d027bd4ad91c8b1318 upstream. ================================= [ INFO: inconsistent lock state ] 4.1.0-rc7+ #217 Tainted: G O --------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/6/0 [HC0[0]:SC1[1]:HE1:SE0] takes: (ext_devt_lock){+.?...}, at: [] blk_free_devt+0x3c/0x70 {SOFTIRQ-ON-W} state was registered at: [] __lock_acquire+0x461/0x1e70 [] lock_acquire+0xb7/0x290 [] _raw_spin_lock+0x38/0x50 [] blk_alloc_devt+0x6d/0xd0 <-- take the lock in process context [..] [] __lock_acquire+0x3fe/0x1e70 [] ? __lock_acquire+0xe5d/0x1e70 [] lock_acquire+0xb7/0x290 [] ? blk_free_devt+0x3c/0x70 [] _raw_spin_lock+0x38/0x50 [] ? blk_free_devt+0x3c/0x70 [] blk_free_devt+0x3c/0x70 <-- take the lock in softirq [] part_release+0x1c/0x50 [] device_release+0x36/0xb0 [] kobject_cleanup+0x7b/0x1a0 [] kobject_put+0x30/0x70 [] put_device+0x17/0x20 [] delete_partition_rcu_cb+0x16c/0x180 [] ? read_dev_sector+0xa0/0xa0 [] rcu_process_callbacks+0x2ff/0xa90 [] ? rcu_process_callbacks+0x2bf/0xa90 [] __do_softirq+0xde/0x600 Neil sees this in his tests and it also triggers on pmem driver unbind for the libnvdimm tests. This fix is on top of an initial fix by Keith for incorrect usage of mutex_lock() in this path: 2da78092dda1 "block: Fix dev_t minor allocation lifetime". Both this and 2da78092dda1 are candidates for -stable. Fixes: 2da78092dda1 ("block: Fix dev_t minor allocation lifetime") Cc: Keith Busch Reported-by: NeilBrown Signed-off-by: Dan Williams Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- block/genhd.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 7694dffe9f0e..b09f5fc94dee 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -422,9 +422,9 @@ int blk_alloc_devt(struct hd_struct *part, dev_t *devt) /* allocate ext devt */ idr_preload(GFP_KERNEL); - spin_lock(&ext_devt_lock); + spin_lock_bh(&ext_devt_lock); idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_NOWAIT); - spin_unlock(&ext_devt_lock); + spin_unlock_bh(&ext_devt_lock); idr_preload_end(); if (idx < 0) @@ -449,9 +449,9 @@ void blk_free_devt(dev_t devt) return; if (MAJOR(devt) == BLOCK_EXT_MAJOR) { - spin_lock(&ext_devt_lock); + spin_lock_bh(&ext_devt_lock); idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt))); - spin_unlock(&ext_devt_lock); + spin_unlock_bh(&ext_devt_lock); } } @@ -691,13 +691,13 @@ struct gendisk *get_gendisk(dev_t devt, int *partno) } else { struct hd_struct *part; - spin_lock(&ext_devt_lock); + spin_lock_bh(&ext_devt_lock); part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt))); if (part && get_disk(part_to_disk(part))) { *partno = part->partno; disk = part_to_disk(part); } - spin_unlock(&ext_devt_lock); + spin_unlock_bh(&ext_devt_lock); } return disk; -- 2.20.1