ZFS: Listable but un-stat():able snapshot

[Peter Schuller]

Hello,

first off, this is on a machine running CURRENT from ~ 2007-05-08, so perhaps 
this is no longer an issue. But I don't remember reading about it anywhere.

zfs list contains among other things (full path obscured, but otherwise 
exactly as-is):

XXX at rsync                      0      -   146G  -
XXX at 200708181011               0      -   146G  -
XXX at rsync2                  126K      -   146G  -

I took the first two snapshots rapidly in succession after each other - I 
believe without any I/O to the fs in between. After I could not "cd" into the 
rsync snapshot, I took another one (rsync2) for testing.

ls XXX/.zfs/snapshot:

200708122313    200708180037    200708181011    rsync           rsync2

ls -l XXX/.zfs/snapshot (username obscured):

ls: rsync: No such file or directory
drwx------  12 YYY YYY  43 Aug 12 22:31 200708122313
drwx------  12 YYY YYY  43 Aug 18 00:30 200708180037
drwx------  12 YYY YYY  43 Aug 18 09:30 200708181011
drwx------  12 YYY YYY  43 Aug 18 09:30 rsync2

cd XXX/.zfs/snapshot/rsync:

cd: no such file or directory: XXX/.zfs/snapshot/rsync

Excerpt of kdump after ktrace ls -l:

 55508 ls       CALL  getdirentries(0x5,0x28214000,0x1000,0x28213054)
 55508 ls       RET   getdirentries 128/0x80
 55508 ls       CALL  lstat(0x28216168,0x28216108)
 55508 ls       NAMI  "200708181011"
 55508 ls       RET   lstat 0
 55508 ls       CALL  lstat(0x28216228,0x282161c8)
 55508 ls       NAMI  "200708180037"
 55508 ls       RET   lstat 0
 55508 ls       CALL  lstat(0x282162e8,0x28216288)
 55508 ls       NAMI  "200708122313"
 55508 ls       RET   lstat 0
 55508 ls       CALL  lstat(0x28211268,0x28211208)
 55508 ls       NAMI  "rsync2"
 55508 ls       RET   lstat 0
 55508 ls       CALL  lstat(0x28211318,0x282112b8)
 55508 ls       NAMI  "rsync"
 55508 ls       RET   lstat -1 errno 2 No such file or directory

I still have the snapshot on the machine and such if anybody wants me to run 
some diagnostic commands.

-- 
/ Peter Schuller

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