On Thu, 2011-02-03 at 13:14 -0500, J. Bruce Fields wrote: > On Thu, Feb 03, 2011 at 01:04:55PM -0500, Nikolaus Rath wrote: > > Hello, > > > > I'm mounting an NFS4 volume from a kernel 2.6.32-27 server in a > > 2.6.37-020637rc2 client. > > Very often, when there is significant IO on the mounted volume, the > > client hangs. The process accessing the mountpoint is stuck in D > > state. Any more attempts to access the mountpoint get stuck in D state > > as well. Shortly after, the kernel reports the task as hanging: > > > > [ 3120.620125] Call Trace: > > [ 3120.620138] [<c05ec44d>] ? _raw_spin_lock+0xd/0x10 > > [ 3120.620146] [<c05eb4b6>] __mutex_lock_slowpath+0xc6/0x120 > > [ 3120.620152] [<c05eb1c5>] mutex_lock+0x25/0x40 > > [ 3120.620158] [<c022e3b3>] do_lookup+0xc3/0x120 > > [ 3120.620164] [<c022fbb2>] link_path_walk+0x402/0x9b0 > > [ 3120.620171] [<c0167b5a>] ? queue_work+0x1a/0x20 > > > > Additional tasks hang at a slightly different point: > > > > [ 3120.620304] [<f90b863d>] ? nfs_access_add_cache+0xcd/0x120 [nfs] > > [ 3120.620326] [<f90b8709>] ? nfs_do_access+0x79/0xc0 [nfs] > > [ 3120.620333] [<c05eb4b6>] __mutex_lock_slowpath+0xc6/0x120 > > [ 3120.620339] [<c05eb1c5>] mutex_lock+0x25/0x40 > > [ 3120.620344] [<c022e3b3>] do_lookup+0xc3/0x120 > > [ 3120.620350] [<c022fbb2>] link_path_walk+0x402/0x9b0 > > [ 3120.620356] [<c0230697>] path_walk+0x47/0xa0 > > [ 3120.620361] [<c0230819>] do_path_lookup+0x59/0xb0 > > [ 3120.620367] [<c02311ff>] user_path_at+0x3f/0x70 > > [ 3120.620374] [<c02005b8>] ? do_linear_fault+0x58/0x70 > > [ 3120.620380] [<c020133a>] ? handle_mm_fault+0xda/0x230 > > [ 3120.620387] [<c0228899>] vfs_fstatat+0x49/0x70 > > > > > > Finally, the client saturates the 100 MBit connection with sending and > > receiving from the NFS server. I'm pretty sure this is garbage data, > > even if the client would copy the entire mountpoint there wouldn't be > > that much data to copy. > > Could you take a look at that traffic with wireshark (or send the raw > packet dump data) and see what that traffic consists of? > > For example it may be repeating the same few operations, in which case > there's probably some kind of infinite loop. Not before upgrading the client. As I said earlier, there are a number of known nasty bugs/hangs in 2.6.37-rc2, so there is no point in repeating the debugging process for them... -- Trond Myklebust Linux NFS client maintainer NetApp Trond.Myklebust@xxxxxxxxxx www.netapp.com -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
