Hello. I've built a kernel from git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git (Date: Fri Nov 19 19:46:45 2010 -0800) and got a kernel oops when tried to access to unplugged, but mounted external usb storage formatted with JFS. Steps to reproduce: mkfs.jfs /dev/sdb1 (unpluggable USB hard drive) mount /dev/sdb1 /mnt/drive cd /mnt/drive touch test sync ..unplug a drive ls Result: BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 IP: __mark_inode_dirty Then I got a kernel coredump. Here is a stack trace: (gdb) bt #0 __mark_inode_dirty (inode=0xffff880078fc1490, flags=<value optimized out>) at fs/fs-writeback.c:990 #1 0xffffffff810e4990 in mark_inode_dirty_sync (mnt=0xffff88007862fd00, dentry=<value optimized out>) at include/linux/fs.h:1687 #2 touch_atime (mnt=0xffff88007862fd00, dentry=<value optimized out>) at fs/inode.c:1505 #3 0xffffffff810dfeb4 in file_accessed (file=0xffff88006afed600, filler=0xffffffff810dfcf8 <filldir>, buf=0xffff88007762bf38) at include/linux/fs.h:1763 #4 vfs_readdir (file=0xffff88006afed600, filler=0xffffffff810dfcf8 <filldir>, buf=0xffff88007762bf38) at fs/readdir.c:41 #5 0xffffffff810e001a in sys_getdents (fd=<value optimized out>, dirent=0x1f61468, count=32768) at fs/readdir.c:214 #6 0xffffffff810279ab in ?? () at arch/x86/kernel/entry_64.S:479 #7 0x00007f8b23d1a4c5 in ?? () #8 0x00000000000002bb in ?? () #9 0x0000000000000000 in ?? () (gdb) p bdi $1 = (struct backing_dev_info *) 0x0 (gdb) p inode->i_mapping->backing_dev_info $15 = (struct backing_dev_info *) 0xffff880078878d48 (gdb) p inode->i_sb->s_bdi $16 = (struct backing_dev_info *) 0x0 I can't do git bisect because on n'th step my system became unbootable. But 2.6.35 doesn't fall. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
