JFFS2 error messages
Hi, A couple of my XOs are reporting what look like FS error messages on boot: [91.463670] JFFS2 notice: (664) check_node_data: wrong data CRC in data node at 0x1ec215f0: read 0x3e7c7e03, calculated 0xf7e1d50c ... is this a known problem? Should I raise a ticket for it, and where is the procedure for this? thx, Bill Bill McCormick Open innovation lab Nortel ESN 393-6298 External (613) 763-6298 ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: JFFS2 error messages
2008/6/3 Bill Mccormick [EMAIL PROTECTED]: A couple of my XOs are reporting what look like FS error messages on boot: [91.463670] JFFS2 notice: (664) check_node_data: wrong data CRC in data node at 0x1ec215f0: read 0x3e7c7e03, calculated 0xf7e1d50c ... is this a known problem? According to Dave Woodhouse, who wrote JFFS2, these notices typically mean that at some point you've hard powered off, and as a result JFFS has some uncommitted data lying around on flash. It's almost always harmless, a part of the journal which was never committed: either it was a new write which hadn't yet been synced, or it was a GC write which just doesn't achieve anything now. However, these messages *could* indicate an actual problem -- we never came up with a good heuristic for when _not_ to complain. Woodhouse suggests that in the future perhaps we should write a 'yes, I know there's a CRC failure' node _after_ the offending node, when we reboot and find it since directly rewriting the node is not an option due to the mechanics of NAND flash; that would help confine these messages to immediately after a hard reboot. At present, you'll keep seeing a bad CRC message every time that particular JFFS node is accessed until it is eventually GC'ed. Anyone want to volunteer to turn the above into a FAQ which would be discoverable on our wiki, so that future wonderers don't have to pry the information from the head of dwmw2? --scott -- ( http://cscott.net/ ) ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: JFFS2 error messages
On Tue, 2008-06-03 at 12:13 -0400, C. Scott Ananian wrote: 2008/6/3 Bill Mccormick [EMAIL PROTECTED]: A couple of my XOs are reporting what look like FS error messages on boot: [91.463670] JFFS2 notice: (664) check_node_data: wrong data CRC in data node at 0x1ec215f0: read 0x3e7c7e03, calculated 0xf7e1d50c ... is this a known problem? According to Dave Woodhouse, who wrote JFFS2, these notices typically mean that at some point you've hard powered off, and as a result JFFS has some uncommitted data lying around on flash. It's almost always harmless, a part of the journal which was never committed: either it was a new write which hadn't yet been synced, or it was a GC write which just doesn't achieve anything now. However, these messages *could* indicate an actual problem -- we never came up with a good heuristic for when _not_ to complain. Woodhouse suggests that in the future perhaps we should write a 'yes, I know there's a CRC failure' node _after_ the offending node, when we reboot and find it since directly rewriting the node is not an option due to the mechanics of NAND flash; that would help confine these messages to immediately after a hard reboot. At present, you'll keep seeing a bad CRC message every time that particular JFFS node is accessed until it is eventually GC'ed. Anyone want to volunteer to turn the above into a FAQ which would be discoverable on our wiki, so that future wonderers don't have to pry the information from the head of dwmw2? I think it's already in trac as an RFE. I even respond to email about it when the email in question isn't HTML. -- dwmw2 ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: JFFS2 error messages
On Tue, Jun 03, 2008 at 05:16:17PM +0100, David Woodhouse wrote: On Tue, 2008-06-03 at 12:13 -0400, C. Scott Ananian wrote: 2008/6/3 Bill Mccormick [EMAIL PROTECTED]: A couple of my XOs are reporting what look like FS error messages on boot: [91.463670] JFFS2 notice: (664) check_node_data: wrong data CRC in data node at 0x1ec215f0: read 0x3e7c7e03, calculated 0xf7e1d50c Anyone want to volunteer to turn the above into a FAQ which would be discoverable on our wiki, so that future wonderers don't have to pry the information from the head of dwmw2? I think it's already in trac as an RFE. I couldn't find such a ticket so I created one: http://dev.laptop.org/ticket/7177 ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
