On Thu, Jun 23, 2011 at 12:17, Mark Whitney <markwhitney@gmail.com> wrote:

>
>
> Thanks for the quick response.  I had some success this time!  My test file
> did not did not disappear mounting with the new yaffs with tags-ecc-off:
>
> root@homebase:~# mount -t yaffs2 -o tags-ecc-off /dev/mtdblock5 /mnt/card/
> yaffs: dev is 32505861 name is "mtdblock5" rw
> yaffs: passed flags "tags-ecc-off"
> 322 data (null) tags cedc7db0
> 194 data (null) tags cedc7db0
> >yaffs: nandmtd2_read_chunk_tags chunk 1002 data (null) tags cedc7db0
> el 0 ser 0 seq 4133
> hused 1 obj 261 chunk168 byte 2048 del 0 ser 0 seq 4123
> root@homebase:~# ls -/mnt/card/l/mnt/card/t/mnt/card/mnt/card/i/mnt/card/
> /mnt/card//mnt/card/
>       2 drwx------    1 root     root          2048 Jun 23 16:14 lost+found
>     261 -rw-r--r--    1 root     root       3293184 Jun 23 16:12 testdata
> root@homebase:~# cat /proc/yaffs
> Multi-version YAFFS built:Jun 23 2011 10:32:11
>
>
> Device 0 "system_a"
> start_block.......... 0
> end_block............ 785
> total_bytes_per_chunk 2048
> use_nand_ecc......... 1
> no_tags_ecc.......... 1
> is_yaffs2............ 1
> inband_tags.......... 0
> empty_lost_n_found... 1
> disable_lazy_load.... 0
> refresh_period....... 500
> n_caches............. 10
> n_reserved_blocks.... 5
> always_check_erased.. 0
>
> data_bytes_per_chunk. 2048
> chunk_grp_bits....... 0
> chunk_grp_size....... 1
> n_erased_blocks...... 759
> blocks_in_checkpt.... 0
>
> n_tnodes............. 117
> n_obj................ 5
> n_free_chunks........ 48693
>
> n_page_writes........ 67
> n_page_reads......... 135
> n_erasures........... 2
> n_gc_copies.......... 66
> all_gcs.............. 14
> passive_gc_count..... 14
> oldest_dirty_gc_count 0
> n_gc_blocks.......... 1
> bg_gcs............... 1
> n_retired_writes..... 0
> n_retired_blocks..... 0
> n_ecc_fixed.......... 0
> n_ecc_unfixed........ 0
> n_tags_ecc_fixed..... 0
> n_tags_ecc_unfixed... 0
> cache_hits........... 0
> n_deleted_files...... 0
> n_unlinked_files..... 0
> refresh_count........ 1
> n_bg_deletions....... 0
> tags_used............ 1664
> summary_used......... 0
> root@homebase:~#
>
>
I was able to preserve my data in tests for far by first mounting the
partition in the new yaffs version with the tags-ecc-off flag and then
re-mounting the partition without the flag:

root@homebase:~# mount -t yaffs2 -o tags-ecc-off /dev/mtdblock5 /mnt/card;
ls -l
 /mnt/card/
yaffs: dev is 32505861 name is "mtdblock5" rw
yaffs: passed flags "tags-ecc-off"
drwx------    1 root     root          2048 Jun 27 22:49 lost+found
-rw-r--r--    1 root     root       4628480 Jun 27 22:47 testdata
 /mnt/card/root@homebase:~# umount /dev/mtdblock5
 /mnt/card/root@homebase:~# mount -t yaffs2 /dev/mtdblock5 /mnt/card; ls -l
/mnt/card/
yaffs: dev is 32505861 name is "mtdblock5" rw
yaffs: passed flags ""
drwx------    1 root     root          2048 Jun 27 22:50 lost+found
-rw-r--r--    1 root     root       4628480 Jun 27 22:47 testdata

Not exactly elegant, but does this seem like a reasonable way to migrate to
the new format?  Is the main danger that I do not get the benefit of error
protection when I do the first mount with the new format?

Thanks