Re: Unionmount and overlayfs testsuite

From: Sedat Dilek
Date: Thu May 29 2014 - 15:29:01 EST

On Thu, May 29, 2014 at 9:25 PM, David Howells <dhowells@xxxxxxxxxx> wrote:
>
> Sedat Dilek <sedat.dilek@xxxxxxxxx> wrote:
>
>> # LC_ALL=C TEST_OVERLAYFS="1" ./run.sh
>> [ run.sh ] TEST_OVERLAYFS is 1
>> ***
>> *** ./run.sh open-plain.test
>> ***
>> [ mount_union.sh ] TEST_OVERLAYFS is 1
>> TEST100: Open O_RDONLY
>> - open_file -r /mnt/a/foo100 -R :xxx:yyy:zzz
>> - open_file -r /mnt/a/foo100 -R :xxx:yyy:zzz
>> TEST101: Open O_WRONLY
>> - open_file -w /mnt/a/foo101 -W q
>> /mnt/a/foo101: Test file not on upper filesystem (line 30)
>
> This looks like the setting up worked. Can you cat /proc/mounts?
>

# cat /proc/mounts
rootfs / rootfs rw 0 0
sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0
udev /dev devtmpfs rw,relatime,size=1965028k,nr_inodes=491257,mode=755 0 0
devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0
tmpfs /run tmpfs rw,nosuid,noexec,relatime,size=393632k,mode=755 0 0
/dev/sda2 /host fuseblk
rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other,blksize=4096
0 0
/dev/loop0 / ext4 rw,relatime,errors=remount-ro,data=ordered 0 0
none /sys/fs/fuse/connections fusectl rw,relatime 0 0
none /sys/kernel/debug debugfs rw,relatime 0 0
none /sys/kernel/security securityfs rw,relatime 0 0
none /run/lock tmpfs rw,nosuid,nodev,noexec,relatime,size=5120k 0 0
none /run/shm tmpfs rw,nosuid,nodev,relatime 0 0
gvfs-fuse-daemon /home/wearefam/.gvfs fuse.gvfs-fuse-daemon
rw,nosuid,nodev,relatime,user_id=1000,group_id=1000 0 0
lower_layer /lower tmpfs ro,relatime 0 0
upper_layer /upper tmpfs rw,relatime 0 0
overlayfs /mnt overlayfs
rw,relatime,lowerdir=/lower,upperdir=/upper/upper,workdir=/upper/work
0 0


...and see a lockdep...

[ 90.360420] =============================================
[ 90.360421] [ INFO: possible recursive locking detected ]
[ 90.360424] 3.15.0-rc7-58.2-iniza-lockdep #1 Not tainted
[ 90.360425] ---------------------------------------------
[ 90.360426] open-file/2896 is trying to acquire lock:
[ 90.360428] (&sb->s_type->i_mutex_key#10/2){+.+.+.}, at:
[<ffffffff811fc325>] generic_file_splice_write+0xa5/0x1b0
[ 90.360440]
[ 90.360440] but task is already holding lock:
[ 90.360441] (&sb->s_type->i_mutex_key#10/2){+.+.+.}, at:
[<ffffffff811d7b54>] lock_rename+0x104/0x110
[ 90.360448]
[ 90.360448] other info that might help us debug this:
[ 90.360450] Possible unsafe locking scenario:
[ 90.360450]
[ 90.360451] CPU0
[ 90.360452] ----
[ 90.360453] lock(&sb->s_type->i_mutex_key#10/2);
[ 90.360456] lock(&sb->s_type->i_mutex_key#10/2);
[ 90.360458]
[ 90.360458] *** DEADLOCK ***
[ 90.360458]
[ 90.360460] May be due to missing lock nesting notation
[ 90.360460]
[ 90.360462] 4 locks held by open-file/2896:
[ 90.360463] #0: (sb_writers#4){.+.+.+}, at: [<ffffffff811eeac4>]
mnt_want_write+0x24/0x50
[ 90.360469] #1: (&type->s_vfs_rename_key){+.+.+.}, at:
[<ffffffff811d7a83>] lock_rename+0x33/0x110
[ 90.360473] #2: (&sb->s_type->i_mutex_key#9/1){+.+.+.}, at:
[<ffffffff811d7b3e>] lock_rename+0xee/0x110
[ 90.360479] #3: (&sb->s_type->i_mutex_key#10/2){+.+.+.}, at:
[<ffffffff811d7b54>] lock_rename+0x104/0x110
[ 90.360484]
[ 90.360484] stack backtrace:
[ 90.360487] CPU: 3 PID: 2896 Comm: open-file Not tainted
3.15.0-rc7-58.2-iniza-lockdep #1
[ 90.360489] Hardware name: SAMSUNG ELECTRONICS CO., LTD.
530U3BI/530U4BI/530U4BH/530U3BI/530U4BI/530U4BH, BIOS 13XK 03/28/2013
[ 90.360491] ffffffff82305750 ffff880055ee97b0 ffffffff8172d4fc
ffff880119740d30
[ 90.360494] ffff880055ee9868 ffffffff810be698 ffff880055ee97f0
ffff880055ee9870
[ 90.360497] 0000001000000000 0000000000000000 2412950908a5652b
0000000000000000
[ 90.360500] Call Trace:
[ 90.360504] [<ffffffff8172d4fc>] dump_stack+0x4d/0x66
[ 90.360508] [<ffffffff810be698>] __lock_acquire+0x1ae8/0x1b60
[ 90.360512] [<ffffffff810bc5ea>] ? mark_held_locks+0x6a/0x90
[ 90.360514] [<ffffffff810c1bf1>] ? __raw_spin_lock_init+0x21/0x60
[ 90.360517] [<ffffffff810babfc>] ? lockdep_init_map+0x9c/0x4a0
[ 90.360520] [<ffffffff810beec9>] lock_acquire+0x99/0x120
[ 90.360523] [<ffffffff811fc325>] ? generic_file_splice_write+0xa5/0x1b0
[ 90.360527] [<ffffffff81735d7b>] mutex_lock_nested+0x6b/0x4d0
[ 90.360529] [<ffffffff811fc325>] ? generic_file_splice_write+0xa5/0x1b0
[ 90.360532] [<ffffffff811fc325>] generic_file_splice_write+0xa5/0x1b0
[ 90.360535] [<ffffffff811fbc76>] direct_splice_actor+0x36/0x40
[ 90.360537] [<ffffffff811fc573>] splice_direct_to_actor+0xc3/0x1e0
[ 90.360540] [<ffffffff811fbc40>] ? splice_from_pipe_begin+0x20/0x20
[ 90.360543] [<ffffffff811fc70c>] do_splice_direct+0x7c/0xb0
[ 90.360547] [<ffffffffa03e54cd>] ovl_copy_up_one+0x5cd/0x730 [overlayfs]
[ 90.360551] [<ffffffffa03e5709>] ovl_copy_up+0xd9/0x110 [overlayfs]
[ 90.360554] [<ffffffffa03e24f8>] ovl_dentry_open+0xc8/0xf0 [overlayfs]
[ 90.360558] [<ffffffff811ca749>] vfs_open+0x29/0x50
[ 90.360561] [<ffffffff811d9422>] do_last+0x672/0x1390
[ 90.360564] [<ffffffff811daf71>] ? link_path_walk+0x71/0x890
[ 90.360567] [<ffffffff811dbcd5>] ? path_init+0x545/0x6a0
[ 90.360570] [<ffffffff810bc700>] ? trace_hardirqs_on_caller+0xf0/0x1c0
[ 90.360573] [<ffffffff811dce88>] ? path_openat+0x78/0x680
[ 90.360575] [<ffffffff811dcecb>] path_openat+0xbb/0x680
[ 90.360579] [<ffffffff811de51a>] do_filp_open+0x3a/0x90
[ 90.360582] [<ffffffff81739de7>] ? _raw_spin_unlock+0x27/0x40
[ 90.360585] [<ffffffff811ec277>] ? __alloc_fd+0xa7/0x130
[ 90.360588] [<ffffffff811cc0a8>] do_sys_open+0x128/0x220
[ 90.360592] [<ffffffff81022805>] ? syscall_trace_enter+0x145/0x260
[ 90.360595] [<ffffffff811cc1be>] SyS_open+0x1e/0x20
[ 90.360598] [<ffffffff81743d98>] tracesys+0xe1/0xe6

- Sedat -
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