SV: Jffss2_write_super erasing all the blocks

Joakim Tjernlund joakim.tjernlund at
Sat Feb 2 14:30:08 EST 2008

This is a long standing issue that I tried to address fairly recently.
Please search the archive and you should find some posts/patch from
me about this.


> -----Ursprungligt meddelande-----
> Från: linux-mtd-bounces at [mailto:linux-mtd-bounces at] För Nikhil
> Bansal (nikbansa)
> Skickat: den 31 januari 2008 20:22
> Till: linux-mtd at
> Ämne: Jffss2_write_super erasing all the blocks
> Hi,
> I have a question about JFFS2 fs. In my setup, I am running JFFS2 on AMD
> Spansion flash (NOR flash). What I noticed was that whenever I erase a
> file from my flash, I see that jffs2_write_super function gets called
> which in turn calls jffs2_erase_pending_blocks(0) which goes ahead and
> deletes all the pending blocks. While this erase is going on super block
> is locked and we can not perform any other operation with JFFS2.
> Can someone please explain the logic behind this or if there is
> something I am missing here?
> Thanks,
> Nikhil
> -----Original Message-----
> From: linux-mtd-bounces at
> [mailto:linux-mtd-bounces at] On Behalf Of llandre
> Sent: Thursday, January 31, 2008 8:54 AM
> To: linux-mtd at
> Subject: JFFS2: file contents in case of data CRC error
> I have a JFFS2 partition on 32MByte NAND device.
> When reading a specific file - see below for details - JFFS2 reports a
> Data CRC error but function nand_correct_data never returns -1, so I
> assume ECC algorithm is able to correct errors.
> However the file is not equal to the original one that has been written
> to NAND. In fact, in the middle of the file, I see a 4-kByte "hole"
> where all bytes are 0.
> Anybody can help me about understanding if this is the expected
> behaviour of JFFS2?
> Thanks in advance.
> bash-2.05# mount -t jffs2 -o ro /dev/mtdblock0 /mnt/nand0 mtdblock_open
> ok bash-2.05# cp -v /mnt/nand0/f.img /tmp/
> jffs2_get_inode_nodes(): Data CRC failed on node at 0x01d55544: Read
> 0x80b8997f, calculated 0x57f0ea8e `/mnt/nand0/f.img' -> `/tmp/f.img'
> --
> llandre
> DAVE Electronics System House - R&D Department
> web:
> email: r&d2 at
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