JFFS2 on NAND flash
gleixner at autronix.de
Thu Jan 31 05:04:10 EST 2002
I tried jffs2 on a NAND flash. Tracking down one ugly bug in fs/jffs2/write.c
i got it basicly working !
Thanks to all of you, who did his job on that jffs2/nand stuff obviously
without having access to a NAND device.
If you write a file a empty dnode is created first.
jfss2_write_dnode(c, f, ri, NULL, 0, phys_ofs, &writtenlen);
jfss2_write_dnode puts NULL & 0 , which is data and datalen into
vecs.iov_base = (unsigned char *)data;
vecs.iov_len = datalen;
and then calls
ret = jffs2_flash_writev(c, vecs, 2, flash_ofs, &retlen);
2 is the number of vecs assigned to this job.
jffs2_flash_writev calls mtd->writev, if available else it calls
mtd_fake_writev. The nand driver supports writev and does not check if the
vecs entry is empty. mtd_fake_writev takes care of this.
I suggest to do the check in jffs_write_dnode (where the wrong count comes
from), although i will include a check in nand.c.
This problem did not show up due to the fact, that obviously none of the
FLASH drivers supports writev. (I could not find one in mtd)
Patch is committed to CVS
Thomas Gleixner, autronix automation GmbH
auf dem berg 3, d-88690 uhldingen-muehlhofen
fon: +49 7556 919891 , fax: +49 7556 919886
mail: gleixner at autronix.de, http://www.autronix.de
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