JFFS2 and bad blocks
I am using an SMC via the MTD layer. On one of the partitions I would like to put a JFFS2 filesystem. Normally I erase the partition and then mount it JFFS2. The problem is that if the partition has a bad block I cannot erase or mount it. Does the bad block handling have to be in the vendor specific nand driver ?
Cheers
Simon.
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Simon Haynes - Baydel
Phone : 44 (0) 1372 378811
Email : [email protected]
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Quoted 5 lines · On Tuesday 03 December 2002 11:23, [email protected] wrote:
I am using an SMC via the MTD layer. On one of the partitions I would like to put a JFFS2 filesystem. Normally I erase the partition and then mount it JFFS2. The problem is that if the partition has a bad block I cannot erase or mount it. Does the bad block handling have to be in the vendor specific nand driver ?
Please use latest MTD-CVS code.
Read http://www.linux-mtd.infradead.org/tech/nand.html
Signature · 5 lines
Thomas ____________________________________________________ linutronix - competence in embedded & realtime linux http://www.linutronix.de mail: [email protected]
I download the CVS stuff mid December and again today. The hardware ran ok before and could use jffs2 without errors but as I added files it was slow and I could not make file systems on partitions which contained bad blocks.
The new CVS code seems to be much quicker and I can erase, mount and copy files to my new filesystem without error. I have set up the specific driver to do soft ecc. I noticed that when I reboot the system and the filesystem gets mounted I get errors. The more writes that occur the more errors I seem to get. I ran a test for a week or so over the break which generated log files. A reboot after this produced thousands of errors but the filesystem seemed ok.
The errors are something like
Empty flash at 0x00469ffcb ends at 0x0046a000
or
jffs2_scan_dirent_node(): Node CRC failed on node at 0x0046a7f0 read 0xffffffff calculated 0xdec8161b
I was wondering if any of you could shed any light on this.
Quoted 16 lines · Thomas Gleixner
Quoted 5 lines · On Tuesday 03 December 2002 11:23, [email protected] wrote:
I am using an SMC via the MTD layer. On one of the partitions I would like to put a JFFS2 filesystem. Normally I erase the partition and then mount it JFFS2. The problem is that if the partition has a bad block I cannot erase or mount it. Does the bad block handling have to be in the vendor specific nand driver ?
Please use latest MTD-CVS code.
Read http://www.linux-mtd.infradead.org/tech/nand.htmlSignature · 5 lines
Thomas ____________________________________________________ linutronix - competence in embedded & realtime linux http://www.linutronix.de mail: [email protected]
__________________________
Simon Haynes - Baydel
Phone : 44 (0) 1372 378811
Email : [email protected]
__________________________
Quoted 13 lines · On Monday 06 January 2003 18:04, [email protected] wrote:
I download the CVS stuff mid December and again today. The hardware ran ok before and could use jffs2 without errors but as I added files it was slow and I could not make file systems on partitions which contained bad blocks.
The new CVS code seems to be much quicker and I can erase, mount and copy files to my new filesystem without error. I have set up the specific driver to do soft ecc. I noticed that when I reboot the system and the filesystem gets mounted I get errors. The more writes that occur the more errors I seem to get. I ran a test for a week or so over the break which generated log files. A reboot after this produced thousands of errors but the filesystem seemed ok.
Quoted 3 lines
The errors are something like
Empty flash at
0x00469ffcbends at0x0046a000
This happens due to NAND specific timed buffer flushing. JFFS2 fills up the write buffer to a full page boundary with 0xff and writes out the buffer to the chip, if you have no consecutive write within 2 seconds. This is done to ensure, that data is written to FLASH. This fill looks like empty FLASH on mount. So JFFS2 is wondering why there is data after the "empty" FLASH. No reason to worry.
Quoted 4 lines
or
jffs2_scan_dirent_node(): Node CRC failed on node at0x0046a7f0read0xffffffffcalculated0xdec8161b
This happens, if the write buffer is not written to FLASH before you power down your system without umount. Then the write buffer is lost and you get this error on mount. This indicates, that you may have lost data.
Quoted 1 line
I was wondering if any of you could shed any light on this.
Signature · 5 lines
Thomas ________________________________________________________________________ linutronix - competence in embedded & realtime linux http://www.linutronix.de mail: [email protected]