XFS with project quota support in Kernel 2.6.28(.9)

[Maarten Vergouwe <Maarten.Vergouwe@xxxxxxx>]

Hi

I have problems in writes that hang for more than 7 seconds because of the the kthreadd daemon keeping a mutex locked for too long.

Is there someone who might be able to help me with that?

I saw that a lot of changes were done on the XFS quota support in later kernels, but the patch list is too long between my kernel and the changed quota system.

process 411 ([khubd], kthreadd)

  pid = 411, tgid = 411, parent = 2, real parent = 2

  baduaddr = 0x00000000, badvaddr = 0x00000000, state = 2, flags = 0x80208040

  policy = 0, prio = 115, static prio = 115, normal prio = 115, rt prio = 0

  pc = vmlinux_flash.elf/context_switch+0x3ac (kernel/sched.c:2668)

                schedule (kernel/sched.c:4496)

  kernel stack

    vmlinux_flash.elf/schedule_timeout+0x24 (kernel/timer.c:1264)

    vmlinux_flash.elf/do_wait_for_common+0xd8 (kernel/sched.c:4715)

                wait_for_common (kernel/sched.c:4732)

    vmlinux_flash.elf/xfs_qm_sync+0x110 (fs/xfs/quota/xfs_qm.c:1076)

    vmlinux_flash.elf/xfs_sync+0x1c (fs/xfs/xfs_vfsops.c:255)

    vmlinux_flash.elf/xfs_fs_sync_super+0x3c (fs/xfs/linux-2.6/xfs_super.c:1202)

    vmlinux_flash.elf/fsync_super+0xc (fs/super.c:270)

process 1082 (this one takes too long and my watchdog doesn't like that)

  pid = 1082, tgid = 230, parent = 228, real parent = 228

  baduaddr = 0x00000000, badvaddr = 0x00000000, state = 2, flags = 0x00422140

  policy = 0, prio = 120, static prio = 120, normal prio = 120, rt prio = 0

  pc = vmlinux_flash.elf/context_switch+0x3ac (kernel/sched.c:2668)

                schedule (kernel/sched.c:4496)

  kernel stack

    vmlinux_flash.elf/__mutex_lock_common+0x108 (kernel/mutex.c:182)

                __mutex_lock_slowpath (kernel/mutex.c:321)

    vmlinux_flash.elf/xfs_trans_dqresv+0x50 (fs/xfs/quota/xfs_trans_dquot.c:628)

    vmlinux_flash.elf/xfs_trans_reserve_quota_bydquots+0xc0 (fs/xfs/quota/xfs_trans_dquot.c:792)

    vmlinux_flash.elf/xfs_trans_reserve_quota_nblks+0x40 (fs/xfs/quota/xfs_trans_dquot.c:847)

    vmlinux_flash.elf/xfs_iomap_write_direct+0x36c (fs/xfs/xfs_iomap.c:486)

    vmlinux_flash.elf/xfs_iomap+0x250 (fs/xfs/xfs_iomap.c:247)

    vmlinux_flash.elf/__xfs_get_blocks+0xb8 (fs/xfs/linux-2.6/xfs_aops.c:1345)

    vmlinux_flash.elf/xfs_get_blocks_direct+0x14 (fs/xfs/linux-2.6/xfs_aops.c:1426)

    vmlinux_flash.elf/get_more_blocks+0x54c (fs/direct-io.c:535)

                do_direct_IO (fs/direct-io.c:816)

                direct_io_worker (fs/direct-io.c:998)

                __blockdev_direct_IO (fs/direct-io.c:1209)

    vmlinux_flash.elf/blockdev_direct_IO_no_locking+0xf0 (include/linux/fs.h:2010)

                xfs_vm_direct_IO (fs/xfs/linux-2.6/xfs_aops.c:1506)

    vmlinux_flash.elf/generic_file_direct_write+0x148 (mm/filemap.c:2102)

    vmlinux_flash.elf/xfs_write+0x460 (fs/xfs/linux-2.6/xfs_lrw.c:745)

    vmlinux_flash.elf/do_sync_write+0xc8 (fs/read_write.c:305)

    vmlinux_flash.elf/sys_write+0x50 (fs/read_write.c:386)

    vmlinux_flash.elf/stack_done+0xdc (arch/mips/kernel/scall32-o32.S:59)

Best regards

Maarten Vergouwe

TASS Belgium