From mboxrd@z Thu Jan 1 00:00:00 1970 From: Suresh Jayaraman Subject: Re: smbd blocks for 120 secs and then hangs in D state Date: Sun, 29 Aug 2010 23:30:02 +0530 Message-ID: <4C7AA022.3000906@suse.de> References: <20100823071702.2437b523@tlielax.poochiereds.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: linux-fsdevel@vger.kernel.org, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, Jeff Layton To: Vijai Baskar Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: samba-technical-bounces@lists.samba.org Errors-To: samba-technical-bounces@lists.samba.org List-Id: linux-fsdevel.vger.kernel.org On 08/28/2010 09:48 AM, Vijai Baskar wrote: > The server and the client are different.. Server is the board and > client is my PC. >=20 >=20 > On Mon, Aug 23, 2010 at 4:47 PM, Jeff Layton wrote= : >> On Mon, 23 Aug 2010 10:40:34 +0530 >> Vijai Baskar wrote: >> >>> Hi all, >>> >>> I am running a samba copy of a 4GB file from my local hard disk to a >>> remote hard disk and then find md5sum of the same file in the remote >>> hard disk through samba read. I do the following to accomplish this: >>> >>> 1. mount -t cifs //ip-addr/data /mnt >>> 2. cp /home/4g /mnt >>> 3. md5sum /mnt/4g >>> >>> After a few iterations of the above operation I get the following >>> warning on the board: >>> >>> echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this messa= ge. >>> [ 6122.450000] smbd =EF=BF=BD =EF=BF=BD =EF=BF=BD =EF=BF=BD =EF=BF=BD= D c0204908 =EF=BF=BD =EF=BF=BD 0 =EF=BF=BD9712 =EF=BF=BD =EF=BF=BD372 0x0= 0000000 >>> [ 6122.480000] [] (schedule+0x2dc/0x328) from [] >>> (io_schedule+0x2c/0x48) >>> [ 6122.500000] [] (io_schedule+0x2c/0x48) from [] >>> (sync_page+0x44/0x50) >>> [ 6122.530000] [] (sync_page+0x44/0x50) from [] >>> (__wait_on_bit_lock+0x5c/0xa8) >>> [ 6122.560000] [] (__wait_on_bit_lock+0x5c/0xa8) from >>> [] (__lock_page+0x88/0xa0) >>> [ 6122.590000] [] (__lock_page+0x88/0xa0) from [] >>> (truncate_inode_pages_range+0x2e4/0x38c) >>> [ 6122.620000] [] (truncate_inode_pages_range+0x2e4/0x38c) >>> from [] (truncate_inode_pages+0x18/0x20) >>> [ 6122.640000] [] (truncate_inode_pages+0x18/0x20) from >>> [] (vmtruncate+0xe4/0x14c) >>> [ 6122.670000] [] (vmtruncate+0xe4/0x14c) from [] >>> (inode_setattr+0x48/0x148) >>> [ 6122.700000] [] (inode_setattr+0x48/0x148) from >>> [] (notify_change+0x188/0x1dc) >>> [ 6122.730000] [] (notify_change+0x188/0x1dc) from >>> [] (do_truncate+0x6c/0x88) >>> [ 6122.760000] [] (do_truncate+0x6c/0x88) from [] >>> (do_sys_ftruncate+0x164/0x170) >>> [ 6122.800000] [] (do_sys_ftruncate+0x164/0x170) from >>> [] (sys_ftruncate64+0x14/0x1c) >>> [ 6122.830000] [] (sys_ftruncate64+0x14/0x1c) from >>> [] (ret_fast_syscall+0x0/0x2c) >>> >>> After this samba daemon hangs in the D state. I changed the values of >>> /proc/sys/vm/dirty_writeback_centisecs to 250 (default 500) and >>> /proc/sys/vm/dirty_expire_centisecs to 1000 (default 3000). But this >>> only delays the problem. ps-ax shows smbd in D state. This problem >>> seems to occur only during samba read. >>> >>> Can someone please provide me a solution for the above problem? >>> >>> regards, >>> vijai >>> >> >> (cc'ing linux-fsdevel and samba-technical as this problem is probably >> better reported there) >> >> The stack trace above is for smbd, so I doubt this has much to do with >> cifs per-se. Just to make sure though -- are the server and client the >> same host? Hint: if so, that configuration is prone to deadlock under >> heavy I/O. >> >> When reporting kernel bugs, it's also a good idea to mention the kerne= l >> version. It might also be helpful to know what the underlying >> filesystem is that's being served out. Care to provide the kernel version and filesystem info requested above? >> >> It looks like the process is hung trying to lock a page. Most likely >> that means that something else is holding that lock and not releasing >> it for some reason. Debugging this will probably mean figuring out >> what's holding that lock and why it's not releasing it. >> Do you have a reliable way of reproducing the problem? Thanks, --=20 Suresh Jayaraman