[linux-lvm] reiserfs panic

[Patrick Caulfield <patrick@tykepenguin.com>]

I'm posting this here partly because I hope Chris Mason is reading(!) and partly
because it may be of some use to others on the list.

There seems to be a problem when reading from a deactivated snapshot of a
reiserfs volume that causes a panic.

The problem is caused by the fact that when a snapshot becomes full, LVM
returns I/O errors for the volume and when reiserfs hits an I/O error it panics.

The solution is, of course, to make your snapshots large enough that this never
happens :-) but just in case this is not possible the following patch may be of
use:


diff -u fs/reiserfs/namei.c.orig fs/reiserfs/namei.c
--- fs/reiserfs/namei.c.orig    Thu Nov 29 16:13:28 2001
+++ fs/reiserfs/namei.c Thu Nov 29 16:34:49 2001
@@ -320,9 +320,10 @@
 
     while (1) {
        retval = search_by_entry_key (dir->i_sb, &key_to_search, path_to_entry, de);
-       if (retval == IO_ERROR)
+       if (retval == IO_ERROR) 
+           return NAME_NOT_FOUND;
            // FIXME: still has to be dealt with
-           reiserfs_panic (dir->i_sb, "zam-7001: io error in " __FUNCTION__ "\n");
+           // reiserfs_panic (dir->i_sb, "zam-7001: io error in " __FUNCTION__ "\n");
 
        /* compare names for all entries having given hash value */
        retval = linear_search_in_dir_item (&key_to_search, de, name, namelen);



patrick