| Message ID | 1447863003-26291-1-git-send-email-fdmanana@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Nov 18, 2015 at 04:10:03PM +0000, fdmanana@kernel.org wrote: > From: Filipe Manana <fdmanana@suse.com> > > Teach _check_dmesg to look for improper RCU usage and circular locking > dependency messages. It's useful to check for these as they might point > to a real problem in the filesystem's implementation (or the current > implementation just confuses the checker, probably worth simplifying > the filesystem's implementation). > > Currently the test btrfs/071 for example triggers such warnings: > > [ 912.924839] =============================== > [ 912.925617] [ INFO: suspicious RCU usage. ] > [ 912.926394] 4.3.0-rc5-btrfs-next-17+ #1 Not tainted > [ 912.927274] ------------------------------- > [ 912.928364] fs/btrfs/volumes.c:1977 suspicious rcu_dereference_check() usage! > [ 912.929626] > [ 912.929626] other info that might help us debug this: > [ 912.929626] > [ 912.931197] > [ 912.931197] rcu_scheduler_active = 1, debug_locks = 1 > [ 912.933822] 4 locks held by btrfs/6400: > [ 912.934558] #0: (&fs_info->dev_replace.lock_finishing_cancel_unmount){+.+...}, at: [<ffffffffa046a193>] btrfs_dev_replace_finishing+0x3e/0x696 [btrfs] > [ 912.948929] #1: (uuid_mutex){+.+.+.}, at: [<ffffffffa046a24a>] btrfs_dev_replace_finishing+0xf5/0x696 [btrfs] > [ 912.950987] #2: (&fs_devs->device_list_mutex){+.+.+.}, at: [<ffffffffa046a263>] btrfs_dev_replace_finishing+0x10e/0x696 [btrfs] > [ 912.953265] #3: (&fs_info->chunk_mutex){+.+...}, at: [<ffffffffa046a278>] btrfs_dev_replace_finishing+0x123/0x696 [btrfs] > (...) > > [ 912.987973] ====================================================== > [ 912.989242] [ INFO: possible circular locking dependency detected ] > [ 912.990583] 4.3.0-rc5-btrfs-next-17+ #1 Not tainted > [ 912.990801] ------------------------------------------------------- > [ 912.990801] btrfs/6400 is trying to acquire lock: > [ 912.990801] (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff8119d202>] __blkdev_get+0xa3/0x3d9 > [ 912.990801] > [ 912.990801] but task is already holding lock: > [ 912.990801] (&fs_info->chunk_mutex){+.+.+.}, at: [<ffffffffa046a278>] btrfs_dev_replace_finishing+0x123/0x696 [btrfs] > [ 912.990801] > [ 912.990801] which lock already depends on the new lock. > [ 912.990801] > [ 912.990801] > [ 912.990801] the existing dependency chain (in reverse order) is: > (...) > > Signed-off-by: Filipe Manana <fdmanana@suse.com> Makes sense to me. Reviewed-by: Eryu Guan <eguan@redhat.com> > --- > common/rc | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/common/rc b/common/rc > index 4c2f42c..dd50aa9 100644 > --- a/common/rc > +++ b/common/rc > @@ -3055,6 +3055,8 @@ _check_dmesg() > -e "Oops:" \ > -e "possible recursive locking detected" \ > -e "Internal error" \ > + -e "INFO: suspicious RCU usage" \ > + -e "INFO: possible circular locking dependency detected" \ > $seqres.dmesg > if [ $? -eq 0 ]; then > echo "_check_dmesg: something found in dmesg (see $seqres.dmesg)" > -- > 2.1.3 > > -- > To unsubscribe from this list: send the line "unsubscribe fstests" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe fstests" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/common/rc b/common/rc index 4c2f42c..dd50aa9 100644 --- a/common/rc +++ b/common/rc @@ -3055,6 +3055,8 @@ _check_dmesg() -e "Oops:" \ -e "possible recursive locking detected" \ -e "Internal error" \ + -e "INFO: suspicious RCU usage" \ + -e "INFO: possible circular locking dependency detected" \ $seqres.dmesg if [ $? -eq 0 ]; then echo "_check_dmesg: something found in dmesg (see $seqres.dmesg)"