I'm using the yaffs2 file system in a device running a TI DM ARM chip along with a 512 MB NAND chip. The Linux kernel version is 2.6.5, and the yaffs version 1.1.2.4,yaffs_fs and 11.2.1,yaffs_guts. The problem we're seeing is that yaffs2 is in some circumstances reporting a used block as free. This seems to happen after either an unmount or powerloss. The first yaffs2 warning is: **>> yaffs chunk 144754 was not erased **>> yaffs chunk 146432 was not erased **>> yaffs chunk 146752 was not erased **>> yaffs chunk 146880 was not erased **>> yaffs chunk 147264 was not erased **>> yaffs chunk 147648 was not erased **>> yaffs write required 7 attempts And, after enough time: page 84227 in gc has no object page 84228 in gc has no object page 84229 in gc has no object page 84230 in gc has no object CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED is set, and the output of /proc/yaffs is as follows on a file system exhibiting the errors described above. YAFFS built:Apr 8 2010 15:21:02 $Id: yaffs_fs.c,v 1.1.2.4 2007-05-02 20:56:15 ddompe Exp $ $Id: yaffs_guts.c,v 1.1.2.1 2007-03-19 21:08:58 rgomez Exp $ Device 0 "ROOTFS" startBlock......... 0 endBlock........... 287 chunkGroupBits..... 0 chunkGroupSize..... 1 nErasedBlocks...... 154 nTnodesCreated..... 800 nFreeTnodes........ 64 nObjectsCreated.... 900 nFreeObjects....... 74 nFreeChunks........ 11987 nPageWrites........ 0 nPageReads......... 0 nBlockErasures..... 0 nGCCopies.......... 0 garbageCollections. 0 passiveGCs......... 0 nRetriedWrites..... 0 nRetireBlocks...... 0 eccFixed........... 0 eccUnfixed......... 0 tagsEccFixed....... 0 tagsEccUnfixed..... 0 cacheHits.......... 0 nDeletedFiles...... 161 nUnlinkedFiles..... 4564 nBackgroudDeletions 0 useNANDECC......... 1 isYaffs2........... 1 Device 1 "VARFS" startBlock......... 0 endBlock........... 79 chunkGroupBits..... 0 chunkGroupSize..... 1 nErasedBlocks...... 15 nTnodesCreated..... 200 nFreeTnodes........ 148 nObjectsCreated.... 300 nFreeObjects....... 140 nFreeChunks........ 4791 nPageWrites........ 0 nPageReads......... 0 nBlockErasures..... 47 nGCCopies.......... 114 garbageCollections. 47 passiveGCs......... 20 nRetriedWrites..... 0 nRetireBlocks...... 0 eccFixed........... 0 eccUnfixed......... 0 tagsEccFixed....... 0 tagsEccUnfixed..... 0 cacheHits.......... 15 nDeletedFiles...... 26 nUnlinkedFiles..... 79 nBackgroudDeletions 0 useNANDECC......... 1 isYaffs2........... 1 Device 2 "DATAFS" startBlock......... 0 endBlock........... 3647 chunkGroupBits..... 0 chunkGroupSize..... 1 nErasedBlocks...... 5 nTnodesCreated..... 25700 nFreeTnodes........ 63 nObjectsCreated.... 13200 nFreeObjects....... 47 nFreeChunks........ 29545 nPageWrites........ 0 nPageReads......... 0 nBlockErasures..... 145 nGCCopies.......... 6414 garbageCollections. 140 passiveGCs......... 0 nRetriedWrites..... 6 nRetireBlocks...... 0 eccFixed........... 0 eccUnfixed......... 0 tagsEccFixed....... 0 tagsEccUnfixed..... 0 cacheHits.......... 0 nDeletedFiles...... 1702 nUnlinkedFiles..... 3490 nBackgroudDeletions 0 useNANDECC......... 1 isYaffs2........... 1 --------------------------------------------------------------------- CONFIDENTIALITY NOTICE: This e-mail and any attachments contain information from DriveCam, Inc., and are intended solely for the use of the named recipient(s). This e-mail may contain confidential information of DriveCam, Inc. and its customers. Any dissemination of this e-mail by anyone other than an intended recipient is strictly prohibited. If you are not a named recipient, you are prohibited from any further viewing of the e-mail or any attachments or from making any use of the e-mail or attachments. If you believe you have received this e-mail in error, notify the sender immediately and permanently delete the e-mail, any attachments, and all copies thereof from any drives or storage media and destroy any printouts of the e-mail or attachments. This message has been content scanned for known viruses, spam, undesirable content and malicious code by the MailGate. ---------------------------------------------------------------------