Hi Artem, I wanted to check the 'white-space-fixup' and re-reading your documentation before, so got delayed in replying. + my mail got moderated again by mailman..
>From: Artem Bityutskiy [mailto:artem.bityuts...@linux.intel.com] [...] >If you are worried about fragmentation, we can discuss this separately. >You can find more about UBIFS journal in my very old UBIFS presentation, >which explains basic ideas behind the UBIFS wandering journal: > >http://www.linux-mtd.infradead.org/doc/ubifs.html#L_documentation > >There is also Adrian's white paper with some design description there. > Thanks much for reminding me about this. I had read your slides long back, but never dig deep into Adrian's slides. so, this was still in my 'To Read' list. But really appreciate your work and presentation. [...] >I do not understand the question. There are no problems in your (b), >neither in "*_Case-2_" described. > >If you meant "*_Case-1_", then yes, there is a piece of doc: > >http://www.linux-mtd.infradead.org/doc/ubi.html#L_flasher_algo > >Basically, "ubiformat" is the "correct" UBI-aware flasher, while >u-boot's "nand write" seems to be a dumb flasher. I guess you have 2 >options: > >1. Teach u-boot's "nand write" to skip empty pages, or may be implement >a separate "clever" flashing command. > Yes, I'll try 'Stefano Babic' suggestion of using u-boot UBI tools. >2. Use UBIFS's "space fixup" feature. This will cause UBIFS to fix-up >all empty pages by basically copying all partially-used PEBs to >different PEBes with empty pages skipping. This will be done on the >first mount, only once, and may cause considerable delays. > >See http://www.linux-mtd.infradead.org/faq/ubifs.html#L_free_space_fixup > Though I had read about 'white-space-fixup' feature earlier too, But somewhere in back of my mind, I thought it was only for "free PEBs" (erased-blocks which had corrupted or no volume-header). But after re-reading the FAQ page, I realized that 'white-space-fixup' is done for all pages, whether in 'free-PEB' or 'used-PEB'. So, This solved my problem.. Thanks much.. >P.S. Looking at the MTD web-site now, when I am not doing any >UBI/UBIFS/MTD work anymore for few years, I am impressed how much stuff >I actually documented there :-) > Absolutely agree. Therefore your file-system is so popular.. Especially the MTD and UBI documentation is not only limited to 'how to use it', Instead I think, it has some advanced details, explanations and reasoning which were quite ahead of its time when it was written. This is something which you and other MTD/UBI/ & UBIFS Authors and Maintainers should be proud of. Thanks again .. with regards, pekon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
