On 07/19/2014 01:59 PM, Martin Steigerwald wrote:

Am Freitag, 18. Juli 2014, 09:36:06 schrieb Chris Mason:

quoted

On 07/18/2014 03:51 AM, Martin Steigerwald wrote:

quoted

Am Dienstag, 15. Juli 2014, 09:21:40 schrieb Chris Mason:

quoted

On 07/14/2014 05:58 PM, Martin Steigerwald wrote:

quoted

Am Montag, 14. Juli 2014, 16:12:22 schrieb Chris Mason:

quoted

On 07/14/2014 11:10 AM, Martin Steigerwald wrote:

quoted

Am Montag, 14. Juli 2014, 17:04:22 schrieben Sie:

quoted

Hi!

While with 3.16-rc3 and rc4 I didn´t have a BTRFS hang in several
days
of
usage, with 3-16-rc5 I had a hang again. Less than a hour since
booting
it.

Since the hang bug I and others had with 3.15 and upto 3.16-rc2
usually
didn´t happen that quickly after boot and since backtrace looks a bit
different from what I have in memory, I post this in a new thread.
See thread "Blocked tasks on 3.15.1" for a discussion of previous
hang
issues.

Probably good to add some basic information on the filesystem:

Do you have compression enabled?  I wasn't able to nail down the 3.15.1
hang before vacation attacked me, but I'm hoping to track it down
today.

Yes. I have.

It just hung again while I was playing PlaneShift.

Back to 3.16-rc4 as rc5 seems to be broke here.

The btrfs hang you're hitting goes back to 3.15.  So 3.16-rc4 vs rc5
shouldn't be a factor.  Are you hitting other problems with 3.16?

On this system it is a matter.

3.16-rc5: Two hangs in one day

3.16-rc4: No hang so far with three days uptime (well with hibernation
cycles in between)

So easy observation for me: 3.16-rc4 fine, 3.16-rc5 broke.

Can you please try this patch on rc5 and look for the printk:

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 3668048..8ab56df 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c

@@ -8157,6 +8157,13 @@ void btrfs_destroy_inode(struct inode *inode)
 		spin_unlock(&root->fs_info->ordered_root_lock);
 	}

+	spin_lock(&root->fs_info->ordered_root_lock);
+	if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
+		list_del_init(&BTRFS_I(inode)->ordered_operations);
+printk(KERN_CRIT "racing inode deletion with ordered

operations!!!!!!!!!!!\n"); +	}
+	spin_unlock(&root->fs_info->ordered_root_lock);
+
 	if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
 		     &BTRFS_I(inode)->runtime_flags)) {
 		btrfs_info(root->fs_info, "inode %llu still on the orphan list",

Did so and again got a hang.

No racing inodes tough:

merkaba:/boot> zgrep -i "racing inode" /var/log/syslog*
merkaba:/boot#1>

Built kernel seems right:

martin@merkaba:[…]> LANG=C grep -ir "racing inode" fs/btrfs
fs/btrfs/inode.c:printk(KERN_CRIT "racing inode deletion with ordered operations!!!!!!!!!!!\n");
Binary file fs/btrfs/inode.o matches
Binary file fs/btrfs/btrfs.o matches
Binary file fs/btrfs/btrfs.ko matches

Backtrace doesn´t seem to contain any function related to inodes.


Back to rc4 again for now.


These hangs seemed to occur first at writing several hundred MiB onto a
high speed SDHC card… yet, they persisted long after the write was finished,
upto to a point where I had to reboot cause machine hung on trying to
switch between tty7 (X11) and tty1 (for diagnosis).

Ok, this is definitely the same hang reported on 3.15.1.  Thanks for
giving the patch a try, I've got another long running test going this
weekend in hopes of triggering it here.

-chris