(Adding the ext2/ext3/ext4 list to Cc) Note that the MMC/SD card driver in question, atmel-mci, is not in mainline, and may be the real cause of this problem. But it looks like there might be a potential problem in the ext3 code as well? Haavard On Thu, 21 Feb 2008 14:17:04 +0800 Hein_Tibosch <hein_tibosch@xxxxxxxx> wrote: > Hi James, > > > I've had all kinds of problems with the SD-card hooked to an NGW100, just as John Voltz reported earlier: > > http://www.avr32linux.org/archives/kernel/2007-November/000421.html > http://www.avr32linux.org/archives/kernel/2007-November/000425.html > > I debugged this problem and my conclusion is: using an SD-card may lead to both BUS-errors and a complete hanging of the system, with 2.6.23.atmel.5 as well as 2.6.24.atmel.1. > > Both the driver for ext2 and ext3 are using this type of function to iterate through a array of inodes: > > static inline ext2_dirent *ext2_next_entry(ext2_dirent *p) > { > return (ext2_dirent *)((char*)p + le16_to_cpu(p->rec_len)); > } > > static inline struct ext3_dir_entry_2 * > ext3_next_entry(struct ext3_dir_entry_2 *p) > { > return (struct ext3_dir_entry_2 *)((char *)p + > ext3_rec_len_from_disk(p->rec_len)); > } > > > Sometimes, rec_len is checked for a zero-value, sometimes the entry is checked thoroughly for validity (like with ext2_check_page() or ext3_check_dir_entry()), but in other cases rec_len isn't checked at all! This is the case in e.g. fs/ext3/namei.c, function ext3_dx_find_entry(). This function is always enabled since 2.6.24 (CONFIG_EXT3_INDEX not used anymore). > > I had a card on which at one place rec_len turned out to be a small negative number. When iterating, it would either cycle for ever (until WDT) or it could enter invalid memory (OOPS: BUS error). > > ( strange though that the rec_len appeared to have a negative number, I just did a "mkfs -t ext3" on Ubuntu. Could that be caused by the Atmel-driver? ) > > I don't yet feel qualified to make a patch for this, I only did it for myself. Maybe someone can pick this up: a validity check should be made before any call to xxx_next_entry(). > > > Regards, > > Hein Tibosch (HeinBali at avr32linux) > > > > James Stewart wrote: > Hi, > > I'm wondering if there are any known issues with booting from SD card on the ATNGW100 using this kernel. I get a bunch of ext2 looking errors and then a stack dump immediately after mounting VFS. 2.6.23.atmel.5 runs perfectly, however. > > This is just compiling using atngw100_defconfig. > > Thanks, > > James > > ------------------------------------------------ > > _______________________________________________ > Kernel mailing list > Kernel@xxxxxxxxxxxxxx > http://duppen.flaskehals.net/cgi-bin/mailman/listinfo/kernel > - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
