SLASH2 · blog

Inode cache bugs

Mar 23, 2009 by pauln

Both this and the one below look to be caused by the reentrancy problem fixed in Zest about 2 weeks ago.

[root@castor mount_slash]# fg
PSC_LOG_LEVEL=2 SLASH_MDS_NID="128.182.58.80@tcp10" LNET_NETWORKS="tcp10(eth1)" USOCK_CPORT=1300 gdb ./mount_slash

#0  0x0000000000404e0c in atomic_dec (v=0x28)
    at ..//..//psc_fsutil_libs/include/psc_util/atomic.h:393
#1  0x000000000040531a in slash2fuse_access (req=0x7fafb0, ino=15294024,
    mask=1) at main.c:229
#2  0x0000000000403ee2 in slash2fuse_listener_loop (arg=0x0)
    at fuse_listener.c:260
#3  0x0000003e8ce073da in start_thread () from /lib64/libpthread.so.0
#4  0x0000003e8c2e62bd in clone () from /lib64/libc.so.6
(gdb) up
#1  0x000000000040531a in slash2fuse_access (req=0x7fafb0, ino=15294024,
    mask=1) at main.c:229
229             fidc_membh_dropref(c);
(gdb) print *c
Cannot access memory at address 0x0
(gdb)

SLASH compilation on Castor

Mar 20, 2009 by pauln

Here are some changes I had to make for building on Fedora Core 10. Note that a symlink was made in /usr/src/kernels.

(psc@castor:projects)$ ls -al /usr/src/kernels/slash2-devel-kernel
lrwxrwxrwx 1 root root 30 Mar 20 13:04 /usr/src/kernels/slash2-devel-kernel -> 2.6.27.19-170.2.35.fc10.x86_64/


Index: psc_fsutil_libs/include/psc_util/atomic.h
===================================================================
--- psc_fsutil_libs/include/psc_util/atomic.h   (revision 5643)
+++ psc_fsutil_libs/include/psc_util/atomic.h   (working copy)
@@ -3,9 +3,12 @@
 #ifndef _PFL_ATOMIC_H_
 #define _PFL_ATOMIC_H_

+#include "psc_types.h"
 #include <sys/types.h>
-#include <asm/bitops.h>
-#include <asm/system.h>
+#include <asm/types.h>
+//#include <linux/bitops.h>
+//#include <asm/system.h>
+#include <asm/cmpxchg.h>

 #include

PSC metadata server status

Mar 5, 2009 by pauln

wolverine (128.182.58.80) is configured as a SLASH2 metadata server. Below is a dump of the ZFS configuration:

(pauln@wolverine:zpool)$ sudo ./zpool status
  pool: wolverine_pool
 state: ONLINE
 scrub: none requested
config:

NAME        STATE     READ WRITE CKSUM
wolverine_pool  ONLINE       0     0     0
  raidz1    ONLINE       0     0     0
    sdb1    ONLINE       0     0     0
    sdc1    ONLINE       0     0     0
    sdd1    ONLINE       0     0     0

errors: No known data errors

To date I’ve been able to successfully run a 10 million file create test (and unlink). Here’s the fio test config:

group 8peReadWrite {
  files_per_dir = 1024;
  tree_depth    = 8;
  tree_width    = 3;
  pes           = 4;
  test_freq     = 0;
  block_freq    = 0;
  path          = /slashfs_client/pauln;
  output_path   = /tmp;
  filename      = 8paeRW_1mbs;
  file_size     = 128m;
  block_size    = 4m;
  thrash_lock   = yes;
  samedir       = yes;
  samefile      = no;
  intersperse   = no;
  seekoff       = no;
  fsync_block   = no;
  verify        = yes;
  barrier       = yes;
  time_block    = no;
  block_barrier = no;
  time_barrier  = no;
  iterations    = 1;
  debug_conf    = no;
  debug_block    = no;
  debug_memory    = no;
  debug_buffer    = no;
  debug_output    = no;
  debug_dtree     = no;
  debug_barrier   = no;
  debug_iofunc    = no;

  iotests (
WriteEmUp [create:openwr:close]
statem    [stat]
  )
}

System calls which should work

Feb 20, 2009 by pauln

The fuse handlers for these calls are located in mount_slash/main.c.

Works  Fs Call       Handler
-----  -----------   ------------
Y      mount()       fuse native.
Y      statfs()      slash2fuse_statfs()
Y      creat()       slash2fuse_create()
Y      open()        slash2fuse_open()
Y      stat()        slash2fuse_getattr()
Y      fstat()       slash2fuse_getattr()
Y      mkdir()       slash2fuse_mkdir()
Y      readdir()     slash2fuse_readdir_helper()
Y      rmdir()       slash2fuse_rmdir_helper()
Y      unlink()      slash2fuse_unlink_helper()
Y      close()       slash2fuse_release() / slash2fuse_releasedir()
?      access()      slash2fuse_access()
N      read()
N      write()
N      readlink()
N      mknod()
N      symlink()
N      fsync()

mount_slash and oprofiler