Corruption: --fix-fixable results in all nlink values = 0

[Gerrit Hannaert <degerrit@web.de>]

Hello,

I recently noticed some errors in my system log, and had already found a directory with a few files in it which could not be deleted. 
So I downloaded the newest reiserfs tools, compiled them and had a shot at reiserfsck --fix-fixable.
Big mistake. My 60GB filesystem had gone from slightly corrupt to becoming completely unmountable by doing this.

Some further analysis led me to the conclusion that *all* fields for nlink had become '0' (something I suppose shouldn't happen).

reiserfsprogs 3.6.3
filesystem version 3.6, created with something from 2.4.16 to .18
gcc used to compile: version 3.1.1 20020722 (prerelease) (SuSE Linux)
kernel 2.4.19 (compiled with same gcc)

What went wrong here? 
Will reiserfsck --rebuild-tree fix this? Or is the error some compilation thing? 
What are my chances to recover the filesystem?

Regards,

- Gerrit



--
luna:/ # mount /home
mount: Not a directory

-- /var/log/messages
Aug 15 19:40:51 luna kernel: reiserfs: found format "3.6" with standard journal
Aug 15 19:40:51 luna kernel: reiserfs: checking transaction log (ide0(3,9)) for (ide0(3,9))
Aug 15 19:40:51 luna kernel: reiserfs: using ordered data mode
Aug 15 19:40:51 luna kernel: vs-13075: reiserfs_read_inode2: dead inode read from disk [1 2 0x0 SD]. This is likely to be race with knfsd. Ign
ore
Aug 15 19:40:51 luna kernel: Using r5 hash to sort names

-- reiserfsck output
/  1 (of   4)/  1 (of 159)/  1 (of 169)bad_stat_data: block 8232, [1 2 0x0 SD (0)], directory SD has bad nlink number
bad_stat_data: block 8232, [2 3 0x0 SD (0)], directory SD has bad nlink number
bad_stat_data: block 8232, [2 13 0x0 SD (0)], directory SD has bad nlink number
bad_stat_data: block 8232, [2 14 0x0 SD (0)], directory SD has bad nlink number
/  2 (of 169)bad_stat_data: block 8233, [2 132 0x0 SD (0)], directory SD has bad nlink number
bad_stat_data: block 8233, [2 1855 0x0 SD (0)], directory SD has bad nlink number
/  5 (of 169)bad_stat_data: block 8755, [2 3793 0x0 SD (0)], directory SD has bad nlink number

-- ALL values of nlink are 0:
luna:/ # zcat /home.debugreiserfs.log.gz | grep "nlink"  | awk '{print $8}' | sort | uniq -c
 382201 0,

-- debugreiserfs output
Filesystem state: consistency is not checked after last mounting

Reiserfs super block in block 16 on 0x309 of format 3.6 with standard journal
Count of blocks on the device: 17638606
Number of bitmaps: 539
Blocksize: 4096
Free blocks (count of blocks - used [journal, bitmaps, data, reserved] blocks): 4826281
Root block: 39819
Filesystem is cleanly umounted
Tree height: 5
Hash function used to sort names: "r5"
Objectid map size 972, max 972
Journal parameters:
        Device [0x0]
        Magic [0x38906a00]
        Size 8193 blocks (including 1 for journal header) (first block 18)
        Max transaction length 1024 blocks
        Max batch size 900 blocks
        Max commit age 30
Blocks reserved by journal: 0
Fs state field: 0x1
sb_version: 2
inode generation number: 12589619
UUID: 00000000-0000-0000-0000-000000000000
LABEL:
Set flags in SB:

INTERNAL NODE (39819) contains level=4, nr_items=3, free_space=3992 rdkey
PTR 0: [dc_number=8387, dc_size=3800] KEY 0: 68140 71445 0x1a07001 IND (1) PTR 1: [dc_number=713991, dc_size=2864] KEY 1: 1671434 1672343 0x4a
...
===================================================================
LEAF NODE (8232) contains level=1, nr_items=8, free_space=128 rdkey (real items 8)
-------------------------------------------------------------------------------
|###|type|ilen|f/sp| loc|fmt|fsck|                   key                      |
|   |    |    |e/cn|    |   |need|                                            |
-------------------------------------------------------------------------------
|  0|1 2 0x0 SD (0), len 44, location 4052 entry count 0, fsck need 0, format new|
(NEW SD), mode drwxr-xr-x, size 1408, nlink 0, mtime 07/19/2002 03:02:40 blocks 3, uid 0
-------------------------------------------------------------------------------
|  1|1 2 0x1 DIR (3), len 1408, location 2644 entry count 51, fsck need 0, format old|
###: Name                     length    Object key           Hash     Gen number
  0: ".                        "(  1)                 1 2           0    1, loc 1400, state 4 not set
  1: "..                       "(  2)                 0 1           0    2, loc 1392, state 4 not set
...
 49: "lost+found               "( 10)             2 26247  2077744896    0, loc 832, state 4 "r5"
 50: "bigfiles.list            "( 13)           2 2241662  2088467072    0, loc 816, state 4 "r5"
-------------------------------------------------------------------------------
|  2|2 3 0x0 SD (0), len 44, location 2600 entry count 65535, fsck need 0, format new|
(NEW SD), mode drwxr-xr-x, size 264, nlink 0, mtime 06/25/2000 19:48:19 blocks 1, uid 0
-------------------------------------------------------------------------------
|  3|2 3 0x1 DIR (3), len 264, location 2336 entry count 11, fsck need 0, format old|
###: Name                     length    Object key           Hash     Gen number
  0: ".                        "(  1)                 2 3           0    1, loc 256, state 4 not set
  1: "..                       "(  2)                 1 2           0    2, loc 248, state 4 not set
  2: "at                       "(  2)                 3 5      208896    0, loc 240, state 4 "r5"
  3: "kbd                      "(  3)                 3 8     2494720    0, loc 232, state 4 "r5"
  4: "bash                     "(  4)                 3 6    25360384    0, loc 224, state 4 "r5"
...