Re: is -1 really too "large" ?

On 10/21/2013 09:52 PM, Dave Jones wrote:
> On Mon, Oct 21, 2013 at 08:40:20PM +0200, Toralf Förster wrote:
>  > got today :
>  > 
>  >  run trinity at Mon Oct 21 20:38:27 CEST 2013 28#-1 M=/mnt/nfsv4
>  > 
>  > rm: cannot remove '/mnt/nfsv4/victims/v1/v2/.nfs0000000000004924000000cb': Device or resource busy
>  > rm: cannot remove '/mnt/nfsv4/victims/v1/v2/.nfs0000000000003fdd000000a9': Device or resource busy
>  > rm: cannot remove '/mnt/nfsv4/victims/v1/v2/.nfs00000000000034230000007a': Device or resource busy
>  > rm: cannot remove '/mnt/nfsv4/victims/v1/v2/.nfs0000000000002d320000006b': Device or resource busy
>  > rm: cannot remove '/mnt/nfsv4/victims/v1/v2/.nfs0000000000001a7c00000035': Device or resource busy
>  > rm: cannot remove '/mnt/nfsv4/victims/v1/v2/.nfs00000000000017600000002a': Device or resource busy
>  > Trinity v1.3pre  Dave Jones <[email protected]>
>  > Done parsing arguments.
>  > Marking all syscalls as enabled.
>  > [init] Enabled 351 syscalls. Disabled 0 syscalls.
>  > [init] Using pid_max = 32768
>  > [init] Started watchdog process, PID is 15311
>  > [main] Main thread is alive.
>  > [main] Generating file descriptors
>  > [main] Something went wrong during nftw(/mnt/nfsv4/victims/v1/v2). (-1:Value too large for defined data type)
> 
> So NFS returned -EOVERFLOW. Not sure why it would do that, but I'm goingto guess it
> came from nftw internally doing an lseek.  lseek's man page suggests..
> 
>        EOVERFLOW
>               The resulting file offset cannot be represented in an off_t.
> 
> 64bit server and 32 bit client perhaps ?
> 
I do only run 32 bit Gentoo Linux (both at host and as user mode linux client).


FWIW in this particular test case I run both an NFS service and a NFS client software at the same UML image do find a reliable rest case to reproduce this hang/cpu burner of one of the linux processes at the host :

tfoerste@n22 ~ $ sudo gdb /home/tfoerste/devel/linux/linux 23921 -n -batch -ex bt
0x08298edc in radix_tree_next_chunk (root=0x14, iter=0x46cc7c60, flags=12) at lib/radix-tree.c:770
770                                             if (node->slots[offset])
#0  0x08298edc in radix_tree_next_chunk (root=0x14, iter=0x46cc7c60, flags=12) at lib/radix-tree.c:770
#1  0x080cc11e in find_get_pages (mapping=0x46ef9b00, start=0, nr_pages=14, pages=0xc) at mm/filemap.c:844
#2  0x080d5c8a in pagevec_lookup (pvec=0x46cc7cc4, mapping=0x14, start=20, nr_pages=20) at mm/swap.c:914
#3  0x080d607a in truncate_inode_pages_range (mapping=0x46ef9b00, lstart=0, lend=-1) at mm/truncate.c:241
#4  0x080d641f in truncate_inode_pages (mapping=0x14, lstart=51539607572) at mm/truncate.c:358
#5  0x08260818 in hostfs_evict_inode (inode=0x46ef9a48) at fs/hostfs/hostfs_kern.c:242
#6  0x0811a8af in evict (inode=0x46ef9a48) at fs/inode.c:549
#7  0x0811b28d in iput_final (inode=<optimized out>) at fs/inode.c:1391
#8  iput (inode=0x46ef9a48) at fs/inode.c:1409
#9  0x08117628 in dentry_iput (dentry=<optimized out>) at fs/dcache.c:331
#10 d_kill (dentry=0x4915d6e0, parent=0x49171dc0) at fs/dcache.c:477
#11 0x08118048 in dentry_kill (dentry=<optimized out>, unlock_on_failure=<optimized out>) at fs/dcache.c:586
#12 dput (dentry=0x4915d6e0) at fs/dcache.c:641
#13 0x081048e3 in __fput (file=0x46cfe900) at fs/file_table.c:264
#14 0x0810494b in ____fput (work=0x46cfe900) at fs/file_table.c:282
#15 0x08094496 in task_work_run () at kernel/task_work.c:123
#16 0x0807efd2 in exit_task_work (task=<optimized out>) at include/linux/task_work.h:21
#17 do_exit (code=1213106688) at kernel/exit.c:787
#18 0x0807f5dd in do_group_exit (exit_code=0) at kernel/exit.c:920
#19 0x0807f649 in SYSC_exit_group (error_code=<optimized out>) at kernel/exit.c:931
#20 SyS_exit_group (error_code=0) at kernel/exit.c:929
#21 0x08062984 in handle_syscall (r=0x46f493d4) at arch/um/kernel/skas/syscall.c:35
#22 0x08074fb5 in handle_trap (local_using_sysemu=<optimized out>, regs=<optimized out>, pid=<optimized out>) at arch/um/os-Linux/skas/process.c:198
#23 userspace (regs=0x46f493d4) at arch/um/os-Linux/skas/process.c:431
#24 0x0805f750 in fork_handler () at arch/um/kernel/process.c:160
#25 0x5a5a5a5a in ?? ()




-- 
MfG/Sincerely
Toralf Förster
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